These proceedings have been prepared electronically 

from copy supplied by the authors. Authors are 

responsible for the content and accuracy of their papers. 

Waldrop, Thomas A,, ed. 

1989, Prsceedings of pine-hardwoad mixtures: a symposium on management and 

ecology of the type; 1989 April 18-19; Atlanta, GA: Gen. Tech. Rep. SE-58. 

Ashevilke, NC: U,S, Department of Agriculture, Forest Service, Southeastern 

Forest Experiment St;ar;ian. 271 pp. 

Thirty-four papers are presented in four categories: Silviculture and Ecology; 

Wildlife; Growth and Yield; and Management, In addition, eight poster 

presentations are summarized and three papers from a general session are 

included, 

Remarks abouc pesticides appear in some technical papers contained in these 

proceedings. Publication of these statements does not constitute endorsement 

or recommendation sf them by the conference sponsors, nor does it imply that 

uses discussed have been registered, Use of most pesticides is regulated by 

State and Federal Law, Applicable regulations must be obtained from appropriate regulatory agencies, 

CAUTION: Pesticides can be injurious to humans, domestic animals, desirable 

plants, and fish and other wildlife--if they are not handled and applied 

properly. Use all pesticides selectively and carefully, Follow recommended 

practices given on the label for use and disposal of pesticides and pescieide 

containers. 

The use of trade or company names of products or senices in the proceedings 

is for the benefit of the reader, Such use does not constitute an endorsement 

or approval of any service or product by the spposfum sponsors to the exclusion of others that may be suitabbe, 

Cover art by Suzy Mefferd, Clemson, SC. 
Proceedings of 

PINE-HARDWOOD MIXTURES: 

A SWPOSIZTM ON MANAGEHm AND ECOLOGY OF THE TYPE 

Edited by 

Thomas A. Waldrop 

Atlanta, Georgia 

April 18-19, 1989 

Sponsored by 

USDA Forest Service: 

Southeastern Forest Experiment Station 

Southern Forest Experiment Station 

Region 8, National Forest System 

Region 8, Cooperative Forestry 

Clemson University: 

Cooperative Extension Service 

Department of Forestry 

Society of American Foresters 

Georgia-Pacific Corporation 

National Association of State Foresters, Southern Region 

Southern Regional Cooperative Extension Foresters 

Published by: Southeastern Forest Experiment Station 

P.O. Box 2680, Asheville, NC 28802 

September 1989 
PREFACE 

Pine-Hardwood Mixtures: A Symposium on Management and Ecology of the Type was 

held on April 18 and 19, 1989, in Atlanta, GA. The meeting was attended by 

over 200 land managers, wildlife managers, and researchers. Thirty-seven 

papers and eight posters were presented over a period of one and one-half 

days. Subject areas included Silviculture and Ecology; Wildlife; Growth and 

Yield; and Management. 

The purpose of the symposium was to stimulate interest in management and 

ecology of pine-hardwood mixtures. Papers were selected by the planning 

committee from abstracts submitted prior to the meeting. Preference was given 

to papers that would identify current research and present research results on 

silvicultural practices, environmental effects, wildlife interactions, and 

productivity. Other papers were selected to provide examples of management 

approaches, describe biologic and geographic limits of the pine-hardwood type, 

and identify research needs. Authors followed the review policies of their 

individual institutions, and the proceedings editor checked each paper for form 

and completeness. 

The planning committee gratefully appreciates the efforts of authors and 

reviewers which contributed to a successful and informative program. Our 

appreciation is also given to Sara Baldwin, Timothy Evans, Donn Geisinger, John 

Haney, Darla Miller, Beth White, and David White for an excellent job of 

operating audio-visual equipment. A special note of thanks is given to the 

moderators who provided additional insight to each topic and kept the 

concurrent sessions on schedule. Moderators included: Gilbert P. Dempsey of 

the Northeastern Forest Experiment Station; M. Boyd Edwards, Jr., of the 

Southeastern Forest Experiment Station; David C. Guynn, Jr., of Clemson 

University; William L. Hafley of North Carolina State University; David Wm. 

Smith of Virginia Polytechnic Institute and State University; and Klaus 

Steinbeck of the University of Georgia. 
DEDICATION TO DOUGLAS R, PHILLIPS 

Douglas R. Phillips 

1943-1988 

Douglas R. Phillips was a native of Jefferson, NC. He received his Bachelor's 

degree from N. C. State University at Raleigh in 1965. His forestry career 

started at the Southeastern Forest Experiment Station as a group leader in 

Forest Survey. After a few years in the field, he returned to N. C. State 

University and received his Master's degree with the hope of getting into 

forestry research. Upon completion of his degree, he was assigned to the Wood 

Quality Research Work Unit at Athens, GA. I served as Doug's supervisor on his 

first research project in 1969, and watched him develop into a very productive 

research scientist with a great deal of curiosity, energy, and leadership 

qualities. Doug's leadership qualities were recognized early on and he was 

appointed as Project Leader of the Silvicultural Guidelines for Managing 

Piedmont Hardwoods Work Unit at Clemson, SC. While at Clemson, Doug was 

encouraged to pursue his Doctorate which he undertook while working full time. 

He became the first forestry Ph.D. graduate at Clemson University in 1985. 

During his tenure at Clemson, he established a new research work unit to study 

the silviculture and management of pine-hardwood mixtures in the Piedmont. In 

1987, his leadership qualities were once again recognized and he was promoted 

to Research Coordinator for the Programs and Legislative Branch of the RPA 

staff in Washington, DC. Doug saw the advantages that could be realized from 

the pine-hardwood mixture concept and promoted its use through his research, 

It was his idea that this symposium on the ecology and management of 

pine-hardwood mixtures be held. It was unfortunate that he was unable to see 

the fruits of his labor since he died of cancer at the age of 44 in 1988. 

It is fitting and proper that we dedicate these proceedings to Doug, a very 

lovable man, with a great sense of humor, vision, and dedication to his work 

and family. His memory will be perpetuated through contributions made by his 

friends to the Douglas R. Phillips Award for Graduate Students in Forestry at 

Clernson University. 

Michael A. Taras, Head 

Department of Forestry 

Clemson University 
PLANNING COMMITTEE 

F. Thomas Lloyd, Chairman 

Southeastern Forest Experiment 

Station, USDA Forest Service 

Thomas A, Waldrop, Proceedings Editor 

Southeastern Forest Experiment 

Station, USDA Forest Service 

Tom L. Darden 

Region 8, USDA Forest Service 

Charles H. Hardin 

Society of American Foresters 

Jacqueline L. Haymond 

Department of Forestry, 

Clemson University 

Charles E. McGee 

Southern Forest Experiment Station, 

USDA Forest Service 

James E. Neal 

Southern Regional Cooperative 

Extension Service 

Daniel H. Sims 

Region 8, USDA Forest Service 

Robert Zahner 

Department of Forestry, 

Clemson University 
CONTENTS 

Page Page 

GEXERAL SESSION Application of Landscape Ecosystem 

Classification in Identifying 

KEYNOTE ADDRESS Productive Potential of PineEcology of the Pine-Hardwood Type . 3 Hardwood Stands .......... 54 

Arthur W. Cooper Steven M. Jones 

The Pine-Hardwood Resource in the Biomass Accrual in Four-Year-Old 

Eastern United States . * Pine-Hardwood Reproduction Across 

Raymond M. Sheffield, Thomas W. a Soil Moisture Gradient ...... 70 

Birch, Earl C, Leatherberry, John C, Adams and Kenneth W, and William H, MeWilliams Farrish 

Are Our Traditional Attitudes 

Restricting Forestry Management 

Options? ............. Robert J. Lentz, Daniel H. Sims, 

and Peter J. Ince 

SILVICULTURE AND ECOLOGY 

Evolution of Forest Types in the 

Southeast ............. 27 

Edward Buckner 

The Decline of the Missouri Ozark 

Forest Between 1880 and 1920 .... 34 

Robert J. Cunningham and 

Carl Hauser 

Characterization of the Hardwood 

Component in Southern Pine Cover 

Types in the Southeast ....... 38 

Gregory A. Ruark and William A. 

Bechtold 

The Gypsy Moth in Pitch Pine-Oak 

Mixtures: Predictions for the 

South Based on Experiences in the 

North ............... 43 

Michael E. Montgomery, Michael L. 

McManus, and C. Wayne Berisford 

Gypsy Moth Impacts in PineHardwood Mixtures ......... 50 

Kurt W. Gottschalk and 

Mark J. Twery 

Fell and Burn to Regenerate 

Mixed Pine-Hardwood Stands: An 

Overview of Research on Stand 

Development ......... Thomas A. Waldrop, F. Thomas 

Lloyd, and James A. 

Abercrombie , Jr . 

Fell and Burn to Regenerate Mixed 

Pine-Hardwood Stands: An Overview 

of Effects on Soil ......... 83 

David H. Van Lear and Peter R. 

Kapeluck 

Sprout Growth Following Winter and 

Spring Felling With and Without 

Summer Broadcast Burning ...... 91 

Donn R. Geisinger, Thomas A. 

Waldrop, Jacqueline L. Haymond, 

and David H. Van Lear 

Influence of Whole-Tree Harvesting 

on Stand Composition and Structure 

in the Oak-Pine Type ........ 96 

James W. McMinn 

The Development of Five-Year-Old 

Mixed Upland Hardwood-Pine Stands . 100 

S.M. Zedaker, D.Wm. Smith, R.E. 

Kreh, and T,S. Fredericksen 

Converting Low-Quality Hardwood 

Stands to Pine-Hardwood Mixtures . . 107 

Charles E. McGee 

Site Quality: The Ecological 

Basis for Pine-Hardwood Management 

Decisions ............. 59 

Robert Zahner and Glendon W. 

Smalley 
Page Page 

Early Crop Tree Presence in Upland 

Pine-Hardwood Stands Related to 

Site Quality and Preharvest Stand 

Condition ............. 112 

hwrence E. N%x, momas F, 

Ruekelshaus, and Steven H, Jones 

A Comparison of Lsblolly Pine 

Growth and Yield on Pure Pine and 

Mixed Pine-Hardwood Stands ..... Ilf 

James B, Haywr~od and John R, 

Toliver 

Even-Aged Mixtures sf Cherrybark 

Oak and Eoblolly Pine in 

Southwestern Arkansas ....... 123 

Wayne K. Clatterbuck 

Wildlife Habitat Quality in 

Varying Mixtures of Pine and 

Hardwood .............. 131 

T, Bently Wigley, R. Laxq 

Willett, Michael E, Garner, and 

Janres B. Baker 

Wild Turkey Activities in Relation 

to Timber Types on the Francis 

Marion National Forest ....... 137 

Hugh R. Still, Jr, and DavXd P. 

Barnam 

The Fox Squirrel (Sciurus 

in Southeastern Pine-Hardwood 

Forests .............. 142 

Susan C. Loeb and Michael R, 

Lennar tz 

Avifauna of the Pine-Hardwood 

Forest in East Central 

Mississippi ............ 149 

Carroll J, Perkins and George A, 

Wurst 

Avian Communities sf Pine-Hardwood 

Forests in the Southeast: 

Characteristics, Management, and 

Modeling .............. 156 

meodore A, Irdeqez and Dean IF, 

S tauf fer 

Volume Growth of Pine and Hardwood 

in Uneven-Aged Loblolly Pine-- 

Upland Hardwood Mixtures ...... 173 

Robert MI, Farrar, Jr., Paul A. 

Muqhy, and Daniel J. Leduc 

Individual Tree Growth 

Relationships in Pine-Wardwooc. 

Mixtures .............. 181 

Paul A. Murphy, Robert H. 

Farrar, Jr., and R. Larry Willett 

Relative Basal Area as it Ap, ies 

to Pine-Hardwood Mixtures in the 

Upper Coastalplain ........ 189 

Hiehael D. Cain 

Dynamics of Mixed Pine-Hardwood 

Stands that Develop from Hardwood 

Encroachment in Pine Plantations . . 197 

W. D. Smith, W, L. Hafley, and 

9". A, Diermf 

Development and Application of a 

Variable DensiGy Yield Model for 

Midsouth Pine-Hardwood Stands ... 200 

John F, Kelly 

Linking Stand-Level and 

Individual-Tree Growth Simulators 

for Mixed Species Stands ...... 206 

F, momas Lloyd 

Bine-Hardwood Forests in NorthCentral Mississippi: An Ecological 

and Eeonomic Perspective ...... 211 

Bmce D, bopold, Garnet H, 

Ueaver, Jmes D, Cutler, and 

Randall @, Warren 

Fine and Hardwood Regeneration 

Ogrions on a Cumberland Plateau 

Site: An Economic Perspective ... 223 

Todd E, Wepp 
Page Page 

Managed Mixed Pine-Hardwood Stands 

Can Yield High Rates of Return on 

Investment ............. 230 

E. Carlyle Franklin 

Hardwood Material Use: Past, 

Present, and Future ........ 236 

William G. Luppold 

Management Options When Loblolly 

Pine Reproduction Invades a 

Clearcut Initiated for Hardwoods . . 242 

Roger W. Dennington 

Lower Coastal Plain Pine-Hardwood 

Stands: Management of Two 

Distinctly Different Site Types . . 246 

Donald J. Lipscomb and Thomas H, 

Williams 

POSTER ABSTRACTS 

Nitrogen Gains and Losses 

Associated with Site-Preparation 

Burning in Southern Pine-Hardwood 

Forests .............. 253 

Lindsay R. Boring, Joseph J, 

Hendricks, and N. Boyd 

Edwards, Jr. 

Developing Feedback Thi.nning 

Policies for Uneven-Aged 

Management with Stochastic Prices . 254 

Robert G. Haight 

Working with Nature: Pine-Hardwood 

Mixtures (Videotape) ........ 255 

Jacqueline L. Haymond and James 

A. Abercronibie , Jr . 

A Growth Projection System for 

Mixed-Species Stands ........ 257 

Ralph S. Heldahl, Roger K. 

Bolton, and Ti~~othy R. 

Bottenfield 

Photos for Estimating Residue 

Loading Before and After Burning 

in Southern Appalachian Mixed 

Pine-Hardwood Stands ........ 258 

Bradford H. Sanders and David H, 

Van Lear 

The Effects of Fire on Table 

Mountain Pine Communities ..... 259 

Greg Sanders and Edward Buckner 

Early Regeneration Response in a 

North Carolina Piedmont Mixed 

Pine-Hardwood Stand ........ 260 

Peter C, Steponkus 

APPENDIXES 

Appendix I--Registration List ... 263 

Appendix II--Alphabetical List of 

Authors ........ 271 

Nutrient Response to Overstory 

Removal and Winter Prescribed Fire 

versus Clearcutting and Summer 

Site Prep Burns in Oklahoma 

Ouachita Mountains ......... 256 

Ronald E. Masters 

Moderator: 

F, Thomas Lloyd 

Southeastern Forest Experiment Station 

USDA Forest Service 

ECOLOGY OF THE PINE-HARDWOOD WPE 

Arthur W. ~oo~er' 

--The m~xed ptne-hardwood type occurs sver a wide array of so;'s and ir a 

number of geographic regtons in the Southeastern iintted States 2uring most recent 

futi glac~al time genera and specres now composing the type #ere confined to the 

Lower Coastal Piarn of the glitf states Rapid northward nrgratrons followed giacral 

retreat and present specres drstrrbulions in the Southeast were reached about 5 000 

yeas ago The vegetation of the Southeast before settlement by Europeans was heavily influenced by fire and other natural disturbances On the Coastal Plain ~t cons~sted 

largely of longleaf pine savannas and woodlands whereas a transition zone of iongleaf 

and other plnes mixed with hardwoods in savanna woodlands accurred along the edge 

of the largely hardwood domrnated forests of the Piedmont plateau V~rtuaily all of thrs 

open pine and prne-hardwood forest rs now gone The present forests of the Southeast 

are classified into tvvo regions In the Oak-P~ne region of the Piedmont stands sf oak 

and hickory mrxed with pine are dominant The Southeastern Evergreen Regron covers 

most of the Coastal Platn Here, In the absence of frre successron produces a mrxture 

of plne and p~ne-hardwood types on the uplands iiVhen distrubance 1s elrmrnated 

upland successton often leads to a mixed forest composed of many of the common 

Southeastern hardwoods 

Management of mixed pine-hardwoods can produce a number of benefits. Since the 

type develops naturally, its management does not usually involve large investments for 

establishment and hardwood control and the environmentally-conlroversial practices 

associated with plantation forestry. Mixed stand management also leads to stands 

that have greater diversity than plantations. Mixed stands have more niches and micro 

habitats, are genetically more diverse, and have greater variety in species composition 

and architecture than plantations. Management of' mixed stands also allows the 

forester opportunities to create diversity and promote more varied wildlife populations. 

IL'lixed stands, under many circumstances, offer the iandswner a management opportunity that is not only closer to his or her pefsonai reasons for owning forest land but 

also may be financially more attractive, Consequently. emphasis on mixed stand 

management may bring more acres into production than would persistent efforts to 

promote plantations. Successful mixed stand management wili require more silviclaltural skill and knowledge and better growth and yield information than we now have. 

It will also require greater sensitivity on the part of foresters to the concerns of private 

landowners. Foresters must learn to incorporate land owner desires and those of the 

public into management practices rather than forcing their views on society. 

INTRODUCTION 

To discuss the ecology of pine-hardwood mi~ures now practiced t hroug hout the Southeast. Although 

is a daunting task. The type occurs in most of the it would be productive to consider the pinemajor forest regions of eastern North America and hardwood mixtures of New England and the Lake 

involves literally thousands of species, hundreds of States, to do so would be mare than can comfortabsoil types, and a number of climatic zones. When ly be handled in my alloted time. 

these are coupled with the wide array of impacts 

man may induce, the breadth required of a competent treatment is substantial. Furthermore, 

another paper on the program will discuss several 

significant aspects of the subject. Consequently, I 

will limit the scope of my comments by discussing 

in detail the pine-hardwood type in the Southeastern United States and some of the ecological 

and social benefits, both real and perceived, to be 

derived from a greater emphasis on management of 

the type. As should be clear, the standard against 

which management of the pine-hardwood type is 

measured is pine plantation management as it rs 

' tiead, Department of Forestry, North Carolrna 

State University, Raleigh, NC. 

EVOLUTION OF THE SOUTHEASTERN 

PINE-HARDWOOD "BYPE 

Although the genera, and even some of the species, 

that combine to make up the vegetation types of the 

present Southeastern pine-hardwood region have 

probably existed for millions af years, the forest 

types which we are now managing have existed for 

much shorter periods of time. Major climatic changes, ecological factors such as soil wype, topography, and Fire, and man's ability to alter the 

operation of these factors have combined in different ways at different points in time to produce an 

ever-changing landscape. In fact, given what we 

now know about the likelihood sf climate change in 

the future, it is quite likely that our landscape will 

continue to cha~ge, 
In beginning our consideration of the history of the 

Southeastern pine-hardwood region, we must go 

back to the beginning of the most recent full glacial 

episode 50-1 00,000 years ago. At that time ice 

sheets began their slow movement south. Whatever 

vegetation existed at that time also migrated southward ahead of the advancing ice. This last cycle of 

glaciation, the Wisconsinan, reached its greatest extent about 20-1 8,000 years ago. At that time ice extended from the Rockies in Canada across the 

northern plains and then southward to southern IIlinois, Indiana, and Ohio and thence eastward 

across southern New York and northern Pennsylvania to Long Island. 

Although there has historically been much debate 

about what the forest types of the Southeast were 

during this full glacial time, it is now generally 

agreed that they were very different in composition 

and distribution than they are now (Delcourt and 

Delcourt 1979). The maximum displacement of 

eastern deciduous species occurred between 

22,000 and 16,500 years ago (Delcourt and Delcourt 1979). Throughout most of the Piedmont and 

Upper Coastal Plain as far south as South Carolina 

boreal species of spruce and jack pine were the 

dominants. This type extended in a broad belt from 

Missouri to North Carolina and northward Po a iine 

running south from southern Minnesota, southern 11- 

linsis, Indiana, and Ohio to Pennsylvania. 

The species that now comprise the eastern 

deciduous forest were confined to relatively small 

populations in the Lower Coastal Plain of the gulf 

states and Florida. During full glacial time, xeric 

oak- hic kory woodland occurred in the Gulf Coastal 

Plain from central Texas to south Georgia and 

southern yellow pines persisted on the Alabama 

Coastal Plain (Delcourt and Delcourt 1 979). Populations of oak-hickory type in Texas and Louisiana 

were isolated from those on the Gulf Coast (Delcourt and Delcourt 1979). Large portions of the 

Southeast were also much more arid than they are 

now (Davis 1981 ). The vegetation of the zone between the oak-hickory-southern yellow pine woodland and the spruce-fir-jack pine forests is not 

known, but Delcourt and Delcourt (1 979) speculate 

that it was a tension zone somewhat similar to the 

northern hardwood zone of today's Lake States. 

Retreat of the continental glaciers 16-1 0,000 years 

ago was rapid and accompanied by an equally 

rapid migration of species northward. In the extreme south, boreal species essentially disappeared 

by 15,000 years ago and were replaced by 

deciduous forest species. In the latitude of North 

Carolina and through most of the Piedmont and 

Upper Coastal Plain spruce and pine forests were 

replaced by components of what we now call northern hardwoods (beech, hemlock, sugar maple) by 

10,000 years ago. Pollen data suggest that at that 

time these forests may have contained southern 

genera such as Liriodendron and Liquidambar, and 

oaks and hickories and thus were not like the true 

northern hardwoods of today (Delcourt and Delcourt 1979). Over the next 5,000 years, northern 

hardwoods were replaced by the species that now 

compose the mixed oak-hickory and pine forests of 

the southeast. The Mixed Mesophytic forest 

migrated to its present location in the Cumberland 

and Alleghany Plateaus. A period of warming and 

drying about 5,000 years ago led to final elimination 

of most cool temperate genera from the Southeast. 

Presumably, changes occurring during the past 

5,000 years led to development of the pre-settlement forest types of the Southeast. 

There have been few extensive studies of the presettlement vegetation of the Southeast. The studies 

that have been done show that presettlement 

Southeastern forests were subject to much higher 

degrees of disturbance, particularly by fire, than 

might have been supposed. For example, Ware 

and others (in press) show that 97% of the Coastal 

Plain uplands and parts of the Piedmont was once 

covered by fire-influenced vegetation such as pine 

savannas and woodlands. Only 3% of the area was 

covered by Southern Mixed Evergreen Forest, 

which has been considered by many Po be the 

"climax" type of the Coastal Plain. Longleaf pine, 

which was once the most abundant tree of the Coastal Plain, now occurs in only about 1 % of its original 

range. Fire-influenced communities have declined 

throughout the 400 years that Europeans have 

been in the South. From this, one can infer that the 

view that succession in the Coastal Plain will lead to 

hardwood dominated forests essentially free of 

pine, although perhaps theoretically correct, will 

occur only if protection from fire is rigorously pursued. In the presence of fire, which was the normal 

state of affairs in the Coastal Plain prior to 

European settlement, forest types will tend more 

toward pure stands of pine or mixtures of pine and 

hardwood than pure stands of hardwood. Ware 

and others (in press) point out that in the Coastal 

Plain hardwoods were once mostly confined to the 

edges of swamps and their expansion into upland 

areas occupied by pine has occurred in the absence of fire and logging. These circumstances 

have led to the concept of a mixed hardwood forest 

as the "climax" type of the Coastal Plain. 

Ware and others (in press) show that there were 

two major regions of presettlement forest within 

what is now the southern yellow pine region. The 

largest of these was a zone covering most of the Atlantic and Gulf Coastal Plain from southeastern Virginia to east Texas in which longleaf pine was the 

dominant species. Many ecologists refer to this 

region as the Southern Mixed Hardwood Forest. 

This zone was a "mosaic of pine savannas, 

sandhills and flatwoods"', within which other, more 
localized communities were mixed (Ware and 

others 1989). Between this vast region dominated 

by longleaf pine and the oak-hickory-shortleaf pine 

forests of the interior of the Piedmont Plateau lay a 

transitional forest in which longleaf pine in almost 

equal proportion was mixed with hardwoods (Ware 

and others 1989). This was not what we now call 

mixed pine and hardwoods, which occurs largely 

following logging, but a savanna woodland with 

varying mixtures of dominants including longleaf, 

shortleaf, and loblolly pine, post, white, and 

southern red oak, hickories, and scrub oaks (Ware 

and others 1989). The forests of this region were 

eliminated by logging many years ago. It is essentially gone from the landscape and no remnants of 

it are preserved anywhere. 

PRESENT FOREST TYPES OF THE SOUTHEAST 

From an ecological perspective, the area covered 

by the pine-hardwood type that is the focus of the 

majority of papers on this program, is essentially 

the Oak-Pine and Southeastern Evergreen Regions 

of Braun (1950) and is virtually conterminous with 

the distribution of the four major southern yellow 

pines (longleaf, loblolly, shortleaf, and slash). The 

Oak-Pine region covers the Coastal Plain of New 

Jersey, Deiaware, and Maryland, par? of the Coastal 

Plain and all of the Piedmont of Virginia, the Piedmont of the Carolinas and Georgia, the Piedmont 

and Coastal Plain of Alabama and Mississippi, and 

a section in southwest Arkansas, northwest 

Louisiana, and east Texas. It is frequently called 

the Eastern Oak-Hickory region because its 

dominant species are oaks and hickories many of 

which occur in the Oak-Hickory region of the midwest. The Oak-Pine region is now characterized by 

stands of mixed oak, with white oak frequently 

dominant, hickory, yellow poplar, beech, and other 

hardwoods. Although the region was probably less 

affected by fire than the Coastal Plain prior to 

European settlement, disturbance was still great 

enough so that pines were a common component 

of the canopy. Now pines, as a result of land clearing for farming, land abandonment and numerous 

cycles of high-grading, are major components of 

the forests of the region. 

The Southeastern Evergreen Region covers the 

Coastal Plain of Southeastern Virginia, the 

Carolinas and Georgia, the Middle and Lower Coastal Plain of Alabama and Mississippi, and a small 

section of west Louisiana and east Texas. As indicated previously, much of the original vegetation of 

this region was longleaf pine maintained by continued fires. Now, the region is a mixture of pine 

forests, primarily loblolly and slash, in a variety of 

different physiographic situations, stands of mixed 

pine and hardwoods, and hardwoods. Bottomland 

and other wet forests are extensively developed. 

Whereas the original "climax" forests of this region 

were undoubtedly pine forests over most of the 

area, now these forests are not naturally reproducing themselves and, where disturbances are 

eliminated, succession is leading toward a mixed 

hardwood forest (Quarterman and Keever 1 962). 

Thirteen upland SAF forest cover types (SAF 1980) 

are included in the region under consideration, including 9 southern yellow pine types and 4 oakpine types (true mixed pine hardwood types). The 

oak-pine types include longleaf pine-scrub oak, 

shortleaf pine-oak, virginia pine-oak, and loblolly 

pine-hardwood. All of these types are, in one way 

or another, successional. The pine types are effectively early successional stages and the oak-pine 

types are transitional to some type of more stable 

hardwood type. 

The U.S. Forest Service recognizes three broad 

types within the region - oak-pine, loblolly-shortleaf 

pine, and longleaf-slash pine (USDA-Forest Service 

1969). These types occur in the Piedmont and 

Coastal Plain of the Southeast from Virginia to east 

Texas and northward into the Ridge and Valley 

Province of Tennessee. 

From a vegetational perspective the Southeastern 

region is one in which the distinction between 

climax and successional types is heavily blurred by 

the activities of man. There are essentially no 

remaining stands of original natural vegetation. It is 

clear that man has altered the forest types of the 

region in a number of ways. By the early 1900's 

lumbering removed the vast stands of pine, chiefly 

longleaf, that occurred extensively throughout the 

region. They were replaced by pines and 

hardwoods with the exact species mix depending 

upon geography and site conditions. Land clearing 

for agriculture eliminated large areas of forest, particularly on the better soils. As soil deteriorated and 

the economic condition of agriculture waxed and 

waned, these lands were abandoned and quickly 

began to revert to pine forest, chiefly shortleaf, Virginia, and loblolly. Hardwoods quickly entered 

these pine stands. Natural succession, without further disturbance, produced stands in which there 

were mixtures of young hardwoods and older 

pines. Without disturbance, these stands eventually 

progressed to hardwood dominance with pines 

present only as scattered, mature trees. With logging, which occurred mostly as high-grading, these 

stands were quickly converted to pine-hardwood 

mixtures or hardwood stands with a varying, but 

smaller, component of pine. In almost all situations 

forests were protected against fire. Such protection 

tended to reduce the likelihood of pine reestablishment and to favor encroachment of hardwoods. 

Regardless of the nature of disturbance, natural successional trends led almost exclusively to the 

production of pine- hardwood mixtures and, eventually, to pure stands of hardwoods. 
The loblolly pine-hardwood type, which is now so 

extensive in the Upper Coastal Plain and the Piedmont where it abuts the Coastal Plain, is a type of 

relatively recent origin. Loblolly pine was originally 

distributed largeiy as single trees or small groups of 

trees in or near swamps and other wetlands (Ashe 

1915). Its prolific early seed production and rapid 

growth enabled it to expand its range following lumbering into abandoned agricultural fields and 

cutover woodlands (Ashe 191 5). These natural 

stands of loblolly pine, frequently mixed with 

hardwood, became the original base of the post 

World War II pine lumber industry of the 

Southeastern Coastal Plain. The species further expanded its range following logging. Its silvical 

characteristics and desirable commercial properties 

caused it to become the favored species for intensive industrial management throughout much of the 

South. 

BENEFITS OF MANAGING MIXED 

PINE-HARDWOOD STANDS 

There appear to be a number of advantages to 

management of mixed pine-hardwood stands, at 

least when compared to plantation monocultures of 

pine Although it is unlikely that the economics of 

management of mixtures will approach that of plantations, there are certain circumstances and situations when reduced dollar gain is more than 

balanced by non-monetary benefits. 

As pointed out in my discussion of the evolution of 

the mixed pine-hardwoods, the type develops 

naturally, as a result of successional forces. 

Hardwoods invade pure stands of pine and become 

components of logged stands of pine or mixed pine 

and hardwoods. In fact, in order to maintain plantations in pine the forester has to devote resources to 

preventing this natural progression of pine to 

hardwood. Substantial sums of money are spent at 

establishment to control hardwood competition, 

either mechanically or with herbicides. In addition, 

fire and herbicides may be used later in the rotation 

to control hardwood encroachment, Such silvicultural practices are costly. Site preparation at establishment can add substantially to the front end cost 

of tree growing as can the cost of eontrolied burns, 

either at establishment or during the rotation. Herbicidal control of hardwoods is not only costly from 

a financial point of view, but it may also be costly 

from an environmental and public relations point of 

view. Many people do not accept herbicides, particularly when they are applied aerially as they often 

must be at establishment. Forest management that 

reduces dependency on chemicals for control of 

competition is, from a public relations point of view, 

highly desirable. Obviously, any management system that can reduce establishment costs and still 

produce a manageable stand, is also highly 

desirabie. 

Management of mixed pine hardwood stands is 

also preferable from a purely biological perspective 

in that it leads to forest stands which are more 

diverse biologically than are pure plantations of any 

species, particularly pine. This diversity is 

manifested in a greater number of species, not only 

trees and forest shrubs and herbs, but also in 

animal species. For example, in Oosting's classic 

study of succession in the North Carolina Piedmont, he found that in young pine stands there was 

only one canopy dominant (loblolly pine) and 10 

young hardwood species (Oosting 1942). In mature loblolly pine stands the total number of canopy 

and transgressive species was about 20, and in mature oak-hickory stands the number was 28. The 

number of niches and microhabitats also increases 

as succession progresses. 

It can be argued that mixed stand management 

promotes greater diversity in other ways, at least in 

comparison to plantation management. By relying 

to a greater extent on natural reproduction which 

encourages populations of both pines and 

hardwoods, the total genetic diversity of the stand is 

increased. Depending upon the origin of the pines 

in the stand, the gene pool may, or may not, be 

wider than that of the pines in a plantation. In light 

of the potential effects of climatic change of forests 

in the Southeast, this reservoir of genes in mixed 

pine-hardwood stands may provide the genetic 

flexibility that the type and its component species 

need to respond to future climatic warming or 

drying. 

Emphasis on mixed stand management promotes 

diversity in another way in that it leads to greater 

landscape variety. Despite their orderly nature, 

plantation pine stands are viewed by many as creating a monotonous landscape. Pine-hardwood 

stands, however, because of the great variety and 

differing architecture of species found in them are 

more diverse in appearance and lead to a 

landscape with more variety in it. What may appear to the forester as a ragged, disorderly, unproductive landscape with patches of mixed-pine 

and hardwoods of varying composition and age, 

presents a greater variety in terms of aesthetic appeal and compositional and structural variation 

than a plantation-dominated landscape. 

Management of the pine-hardwood type actually 

presents the forester with opportunities to create 

diversity through management practices. Through 

manipulation of species composition and age structure, the manager has a wide variety of options for 

creating stands of differing species composition 

and structure. Such different stands will contain 

populations of different lesser plant and associated 

animals species thus further contributing to the ob- 
jective of promoting diversity. Because diversity is 

so much on the mind of forest managers and the 

public today, any practice which can reasonably be 

said to promote diversity is likely to find far wider acceptance with the public than will intensive, plantation forestry. 

Mixed stands also favor more diverse wildlife 

populations. Pine plantations are noted for their 

limited ability to support large wildlife populations. 

Mixed pine-hardwood stands, on the other hand, 

can be expected to support substantial populations 

of many of our important game species. Deer, 

turkey, squirrel and rabbits are more likely to survive in large numbers in mixed stands. Quail are 

perhaps the only major game species favored by 

pure pine stands, and they do not survive without 

management assistance from a controlled burn 

program. Additional variety can be added by allowing dead pines and hardwoods to persist in mixed 

stands, a practice hardly compatible with plantation 

managment and clearcut regeneration. Although 

wildlife populations differ with differing mixes of 

pine and hardwoods, and will change as stands 

age and the mix of pine and hardwoods and of 

hardwoods changes, the manager is clearly promoting a social benefit by managing for stand mixtures. 

Pine-hardwood mixtures also are probably aesthetically more appealing than are pure stands of pine. 

Although the forester is proud of a well-established, 

rapidly growing pine plantation regenerated with 

genetically improved stock, most non-foresters look 

on such stands as they do agricultural fields--as 

uninteresting, intensive uses of land for production 

purposes. They do not view plantations as forests. 

A pine-hardwood mixture, with its towering old 

pines and its ragged, multispecies hardwood understory, is much more a "forest" to the non-forester. 

In addition, older stands of mixed-pine and 

hardwoods, usually with no effort from the 

manager, develop significant populations of the 

rarer forest wildflowers and invertebrates that many 

forest lovers regard as the major benefit of forest 

management. With just a few exceptions, such as 

the pink ladyslipper, few wildflowers occur in pine 

plantations. On the other hand, the major locations 

where we seek spring and summer wildflowers is in 

deciduous woodlands. Many members of the 

general public are reacting negatively to monocultural forestry. To the extent that we can move to 

management of mixtures, it seems we may well 

recapture some of our lost support among the 

general public. 

Management of mixed stands also presents an attractive financial alternative to private, non-industrial landowners who have neither the money or 

the desire to manage intensively for pine. Many 

private landowners hold their land only incidentally 

for production of timber. They are more interested 

in the "other" benefits that can be derived from the 

woods they own. When approached with an intensive, monocultural management plan, such landowners recoil and turn to no management at all as 

their only perceived alternative. If we present such 

owners with true alternative land management 

schemes that involve managing mixed stands, 

using cutting regimes that leave a substantial 

amount of the stand after each entry, promoting 

plant and animal diversity, providing for structural 

diversity by leaving dead standing timber and 

promote fallen dead wood, and maintaining the 

values of the forest on which the owner puts emphasis, we run a much better chance of having our 

proposal accepted. In addition, under certain conditions management of mixed stands may actually 

be more attractive financially than plantations 

management. 

Presentation of genuine management alternatives to 

private owners may have the effect of bringing more 

land into production than might otherwise occur. 

Many and, perhaps, the majority of small landowners, are simply not interested in intensive forest 

management. They can neither afford it nor can 

they accept its consequences in terms of perceived, 

or real, environmental damage. The net result is 

that the lands of such owners are effectively 

removed from those that might potentially be harvested. We may well be able to accomplish the objective of bringing more land into production to 

meet our timber goals by harvesting such lands 

more "lightly" and using practices which more closely approximate nature than by insisting on intensive 

forestry. 

PROBLEMS IN MANAGEMENT OF THE 

PINE-HARDWOOD TYPE 

It should be clear, however, that management of 

mixed stands is no panacea for the social and environmental problems that now beset forestry. 

There are a number of problems that will arise from 

mixed stand management and we should consider 

these well in making our plans for furthering such 

management. 

First, it is likely that mixed stand management will 

require more silvicultural knowledge than we now 

have. More species are involved and we know very 

little about the silvics of some of these. For example, we are all well aware of the difficulty that we 

have encountered in regenerating oak on many 

lands that previously supported oak throughout the 

South. In a system stressing mixed composition in 

the managed stand, we well may not know enough 

about certain species to be able to manage them effectively. Further, we may not yet have the silvicultural skills - systems -to promote certain types of 

management. This is certainly true when our concern is lesser plant species or invertebrates. We 
simply have too little experience with their management to be sure we can meet public demands for 

their production. 

It is a certainty that we wilt need more and better information on growth and yield. Fortunately, a number of researchers are now beginning the 

development of growlh and yield projections for 

mixed stands. A number of these are featured at 

this symposium. It is clear that we will need this information in order to make informed decisions 

about management alternatives and to develop a 

sound base on which to project the economics of 

mixed stand management. 

Mixed stand management will require more sensitivity of the foresters making management recommendations than we have probably seen in the 

past. The usual posture of the forester when confronted with someone who criticizes professionallyaccepted forest management practices is to regard 

the person as poorly informed. The forester assumes that if the person were "educated" to understand the forester's viewpoint, then the 

disagreement would go away. As Magill (1 988) 

points out, professionals seem unable to accept the 

opinions of the public as sound, because they have 

not been scientifically reached, but rat her regard 

them as "uninformed, emotional, and unimportant." 

As a consequence, professionals believe that in interacting with the public they must shape public 

opinion rather than incorporate it into their management policies (Mag ill 1 988). This unwillingness to listen to the public and accept its views as valid lies at 

the base of many of today's resource disputes. How 

many times has each of us said, "If we could just 

educate the public about clearcutting, they would 

understand the practice and accept it." My guess is 

that we could spend the rest of our lives explaining 

clearcutting and our opponents will never accept it. 

in short, there is a clear distinction between forcing 

our views on the public and incorporating their 

views into our management programs. 

CONCLUSIONS 

Mixed stand management affords us an opportunity 

to incorporate many values about which the public 

feels strongly into forest management and, by so 

doing, making allies of persons who are now our bitter foes. in managing mixed stands, we will not 

have ts emphasize controversial practices such as 

intensive site preparation and clearcutting. We can 

manage for timber production, albeit at a lower 

level of intensity, while at the same time managing 

For larger populations of the wildlife and lesser plant 

and animal species that members of the public 

value highly. We can also manage for aesthetics 

and emphasize practices that are likely to bring into 

product ion acres that othewise might be unproductive from the perspective of timber production. 

In a way, mixed stand management may well offer 

us an opportunity to regain some of our natural constituency in the public that we now seem to antagonize by viPtually everything we do. Let us hope 

I am right and, if I am, that we as a profession are 

wise enough to take advantage of the opportunity. 

LITERATURE CITED 

Ashe, W. W. 191 5. Loblolly or North Carolina pine. 

North Carolina Geological and Economic Survey, 

Bulletin 24. Raleigh: North Carolina Geological 

and Economic Survey. 176 p. 

Braun, E. L. 1950. Deciduous Forests of Eastern 

North America. Philadelphia: The Blakiston Company. 596 p. 

Davis, M. B. 1981. Quaternary history and the 

stabililty for forest communities. pp. 132-1 53. In: 

West, D. C. and D. 8. Botkin, eds. Forest Succession, Concepts and Application. New York: 

Springer-Verlag. 

Delcourt, P. A.; Delcourt, H. R. 1979. Late Pleistocene and Holocene distributional history of the 

deciduous forest in the Southeastern United 

States. pp. 79-107. In: H. Leith and E. Landolt, 

eds. Contributions to the Knowledge of the Flora 

and Vegetation in the Carolinas, Vol. 1. Zurich: 

Versft"entlichungen des Geobstanischen institutes 

der Eidg. Techn. Hochschule, Stiftung Rubel, Heft 

68. 

Magill, A. W. 1988. Natural resource professionals: 

the reluctant public servants. Environmental 

Professional 1 0:295-303. 

Oosting, H. J. 1942. An ecological analysis of the 

plant communities of Piedmont, North Carolina. 

American Midland Naturalist 28(1): 1-1 26. 

Quarterman, E.; Keever, C. 1962. Southern mixed 

hardwood forest: climax in the Southeastern 

Coastal Plain, U.S.A. Ecological Monographs 

32: 167-1 85. 

Society of American Foresters. 1 980. Forest Cover 

Types of the United States and Canada. F. H. 

Eyre, ed. Washington: Society of American 

Foresters. 148 p. 

U. S. Department of Agriculture, Forest Service. 

1969. A Forest Atlas of the South. New Orleans: 

Southern Forest Experiment Station and 

Asheville: Sdutheastern Forest Experiment Station. 27 p. 

Ware, S. ; Frost, C. C.; Doerr, P. [in press]. 

Southern mixed hardwood forest (the former 

longleaf pine forest). Chapter 11. In W. H. Martin, ed. Biotic communities of the southeastern 

United States. Voi. 1 , Terrestrial Communities. 

New York: John Wiley & Sons. 
THE PINE-WAR D RESOURCE IN THE EASTERN 

UNITED STATES 

Raymond M. Sheffield, Thomas W. Birch, Earl C. Leatherberry, and 

William H. ~c~illiams' 

.-In the Eastern Un~ted States, 31 million acres of timberland are classrf~ed as pinehardwood. Many additional stands classified as pine or hardwood types are also diverse mgxtures of sohood and hardwood species. The pine-hardwood resource 1s c~ncentraaed in the 

South, Natural forces and human activity cause these mixed stands to be transitory and dynamic. 

INTRODUCTION 

Mixtures of pine and hardwood are an inevitable 

component of the landscape wherever pines and 

other sofiwood species exist. Pine-hardwood 

stands form one of the major Eastern United States 

ecosystems (Garrison and others 1977). Once 

viewed as an end result to be avoided from a timber 

management perspective, mixed stands of pine and 

hardwood are now recognized as a viable, manageable forest resource (Phillips and Abercrombie 

1987). Mixed stands supply significant quantities of 

timber, diverse habitats for wildlife, and large 

acreages for recreation. Perhaps the most important benefit Is the diversity, both biological and esThis paper summarizes existing data documenting 

the extent of the pine-hardwood resource in the 

Eastern United States. These data were collected 

during periodic inventories conducted in each State 

by the USDA Forest Service. Forest Inventory and 

Analysis (FIA) Research Work Units at the North 

Central, Northeastern, Southeastern, and Southern 

Forest Experiment Stations, which are responsible 

for these broad-scale inventories in their respective 

sections of the Eastern United States (figure I), 

provided the data for this descriptive analysis. For 

reference purposes the data have been dated 1989, 

but the statistics are from the most recent inventory 

'Research Forester. Southeastern Forest Experiment 

Station, Asheville, NC; Forester, Northeastern Forest 

Experiment Station, Broomali, PA; Geographer, North 

Central Forest Experiment Station, St. Paul, MN; and 

Research Forester, Southern Forest Experiment Station, Starkville, MS. 

Figure 1 .--Delineations of the Eastern United States, 

by regions of inventory responsibility. 
of each State and have not been updated to a common date. Inventory dates for individual States 

range from 1972 to 1 988; inventories have been 

completed in most of the States involved since 

1980. Most of the data presented are totals for the 

entire Eastern United States. Additional data are 

presented for the North and South. The North is 

comprised of the North Central and Northeast 

regions as depicted in figure 1; the South is made 

up of the South Central and Southeast regions. 

DEFINlNG THE rVPE 

Any estimate of mixed pine-hardwood acreage 

must be related to a definition of what constitutes a 

mixed stand. Standards used by FIA in classifying 

forest types are based on the stocking of softvvoods 

present in a stand relative to the total stocking of all 

species. A softwood forest type is assigned to all 

stands in which softwoods (excluding cypress) constitute 50 percent or more of the total stocking. 

Hardwood types are assigned when the softwood 

propofiion is less than 25 percent (more than 75 

percent hardwoods). All stands with between 25 

and 50 percent softwood stocking are assigned an 

oak-pine type (referred to as pine-hardwood 

throughout the paper). The totals established for 

pine-hardwood stands in this paper are based on 

these forest type standards. 

We acknowledge that these forest type standards 

exclude a poflion of the forest resource that could 

be described as mixed stands of pine and 

hardwood. An extreme interpretation of forest type 

guidelines could include as pine-hardwood every 

stand except those that are 100 percent softwood 

or 100 percent hardwood. Perhaps the most realistic way to portray the relative magnitude of mixed 

stands is to array all stands on a continuum between 0 and 100 percent softwood stocking. Figure 

2 displays a frequency distribution for timberland in 

Percent of total 

60 j 1 I Hardwood Pine-hardwood Pine 

V 

0-30 11-20 21-30 31-40 41-50 5180 61-70 71-80 81-90 91-100 

Softwood proportion 

Figure 2.--Percentage distribution of timberland in 

the South, by softwood stocking proportion. 

the South by 10-percent softwood stocking 

categories. More than half of the South's timberland is in the two lowest categories of softwood 

stocking. In other words, hardwoods make up 80 

percent or more of the stocking on more than half 

of the South's timberland. Except for the 91 -1 00 

percent class, the remaining timberland is distributed almost equally among the remaining stocking categories. Stands classed as pine-hardwood 

are highlighted on the chart. The reader can approximate the impact of classifying a wider range of 

softwood proportions on the estimates of mixed 

stand area. 

AREA 

As defined, pine-hardwood stands currently occupy 

some 31.2 million acres throughout the East (table 

1). Across this region, pine-hardwood stands account for 8.7 percent of all timberland. Mixed 

stands are concentrated in the South, where pines 

are more common. About 27.2 million acres, nearly 

15 percent of the timberland area, are classified as 

Table 1.--Area of pine-hardwood stands in the Eastern United States, by 

detailed type and region 

Detailed 

Million acres 

White pine-hardwood 

E, redcedar-hardwood 

Longleaf pinewscrub oak 

Shortleaf pine-oak 

Virginia pine-hardwood 

Lsblolly pine-hardwood 

Slash pine-hardwood 

Other pine-hardwood 

All pine-hardwood 31.2 4.0 
United States classified as pine-hardwood forest 

tY pe. 

pine-hardwood in the South. The remaining 4.0 million acres are in the North. 

Concentrations of pine-hardwood acreage are clearly indicated by mapping each county according to 

the proportion of timberland classed as pinehardwood (figure 3). Most of the South's counties 

have more than 8 percent of their timberland classified as pine-hardwood. A notable exception includes counties along the Mississippi River that 

contain mostly boltomland hardwood forests. Further north, pine-hardwood stands occur less frequently but remain a common component of the 

landscape in much of Missouri. Kentucky. southern 

Illinois, Indiana, and Ohio, and northeastward to 

Maine. 

The primary softwood species that mix with 

hardwoods change dramatically with geography. 

Even within local areas, many different softwood 

species may form various mixtures with hardwood 

species. FIA recognizes seven different pinehardwood detailed types plus an "other" category. 

These detailed types are named according to the 

primary softwood species present in combination 

with hardwoods, and their occurrence follows the 

range of each individual softwood species. These 

detailed types are listed and briefly described 

below. Scientific names of species are in table 2. 

(1 ) Slash pine-hardwood. Slash pine and 

hardwood mixtures are confined to the 

southernmost States, where the slash pine ecosystem is located (Sheflield and others 1983). Slash 

pine-hardwood stands total 1.7 million acres. They 

occur most commonly in Florida, Georgia, 

Alabama, and Mississippi. 

(2) Longleaf pine-scrub oak. This combination is 

more widely distributed than slash pine. but it is still 

generally confined to the southern areas2 Longleafscrub oak mixtures occupy 1.3 million acres and 

are common in ponions of Mississippi, Alabama, 

Florida, Georgia, and the Carolinas. 

 ell^, John F.; Bechtold, William A The longleaf pine 

resource. In: Longleaf pine management symposium 

proceedings; 1989 April 4-6; tong Beach, MS. (in process), 
Table 2,--Cornon and scientific names of referenced 

tree species 

Contaaon nme Scientific name 

Softwoods : 

Eastern hemlock 

Eastern redcedar 

Emtern white pine 

Fir 

Loblolly pine 

Longleaf pine 

Pitch pine 

Pond pine 

Shortleaf pine 

Slash pine 

Spruce 

Table Mountain pine 

Virginia pine 

Hardwoods: 

Blackgum/tupelo 

Chestnut oak 

Laurel oak 

Northern red oak 

Wed maple 

Scarlet oak 

Southern red oak 

Swee tgum 

Water oak 

White oak 

Willow oak 

Yellow-poplar 

Tsuga canadensis (L.) Carr. 

Juniperus virginiana L. 

-- Pinus strobus L. 

Abies SEE. Mill. 

Pinus taeda L. 

Pinus palustris Mill. 

Pinus rigida Mill. 

Pinus serotina Michx. 

Pinus echinata Mill. 

Pinus elliottii Engelm. 

Picea a. A. Dietr. 

Pinus pungens Lamb. 

Pinus virginiana Mill. 

Nyssa SEE. L. 

Quercus prinus L. 

Quercus laurifolia Michx. 

-- Quercus rubra L. 

-- Acer rubrum L. 

Quercus coccinea Muenchh. 

-- Quercus falcata Michx. 

Liquidambar styraciflua L. 

Quercus nigra L. 

-- Quercus alba L. 

Quercus ~hellos L. 

Liriodendron tulipifera L. 

(3) Lobkolly pine-hardwood. This mixture is by far 

the most common, covering 14 million acres. 

Loblolly pine occurs across an extensive 

geographic area in association with a wide range of 

hardwood species on both upland and bottomland 

sites. The occurrence of this mixture follows the 

natural and introduced range of the species (McWilliams and Birdsey 1984; Sheffield and Knight 

1983). It is found throughout much of the South, extending as far north as Arkansas, Kentucky, Virginia, Maryland, and Delaware. 

(4) Shortleaf pine-oak. Shortleaf pine mixes with 

numerous upland oak species to form the second 

most prevalent pine-hardwood type (6.1 million 

acres). These mixtures occur throughout much of 

the South and extend into the North. The most significant concent rations exist from Arkansas, eastern 

Texas, eastward through Mississippi and Alabama, 

and then noeheastward through the Piedmont 

Plateau of the Southeast (McWilliams and others 

1986). The type is also common in Missouri, Tennessee, Kentucky, West Virginia, and New Jersey. 

(5) Virginia pine-hardwood. This type occupies 

some 2.7 million acres. It is not found in the extreme southern portion of the South, but occurs 

with high frequency in North Carolina, Virginia, Tennessee, West Virginia, and Kentucky. 

(6) Eastern redcedar-hardwood. This mixture, totaling some 1.6 million acres, is the major non-pine association included in the pine-hardwood group. 

Redcedar-hardwood stands are especially 

prominent in Tennessee, Kentucky, and Missouri. 

They are less prominent but common over a much 

wider area. 

(7) White pine-hardwood. White pine-hardwood 

mixtures are the most prevalent pine-hardwood 

type in the North. The type occurs with regularity in 

the Appalachian Mountains as far south as northern 

Georgia. Eastern hemlock is included in this association. 

(8) Other pine- hardwood. This group includes all 

other pine species that occur in association with 

hardwoods. Pond, pitch, and Table Mountain pines 

are the major pine species comprising this group. 

The majority of the pine-hardwood resource is controlled by nonindustrial private landowners, as are 

most forest ecosystems in the Eastern United States 

(U.S. Department of Agriculture 1988a). These landowners control 69 percent of the pine-hardwood 

resource (table 3)--66 percent in the South and 84 

percent in the North. More than 1 1 percent of pinehardwood stands are on public land, whereas 20 

percent, or 6.3 million acres, are controlled by 

forest industry. 

Across all ownerships and regions, significant portions of the pine-hardwood resource are found in 

each of three stand-size classes--sap1 ing-seedling, 

poletimber, and sawtimber (figure 4). A fourth 

category, nonstocked, includes stands so poorly 

stocked that a stand-size classification is not meaningful. Excluding these nonstocked stands, 43 percent of the pine-hardwood stands are dominated by 

sawtimber-size trees, 28 percent have a 

predominance of poletimber-size trees, and 29 percent are primarily stocked with trees in the saplingMillion acres 

14 1 

" 

Sapling-Seedling Poletimber Sawtimber Nonstocked 

Stand-size class 

Figure 4.--Area of pine-hardwood forest type in the 

Eastern United States, by stand-size class and 

reg ion. 
Table 3.--Area of pine-hardwood stands in the Eastern United States, by stand 

size, stand origin, and ownership class 

Stand size All Forest Other Public and origin ownerships industry private 

Million acres 

Sapling-seedling: 

Planted 2.5 

Natural 

Tot a1 

Poletimber: 

Planted 

Natural 

Total 

Sawtimber: 

Planted 

Natural 

Total 

Nonstocked (natural) 0.3 0 0.1 0.2 

All sizes: 

Planted 

Natural 

Tot a1 312 3.5 6.3 21.4 

seedling size group (less than 5.0 inches d. b. h.). 

Concentration in the sawtimber group is evident in 

both major regions. Sapling-seedling stands are 

more common in the South than the North, reflecting the higher rates of timber harvest in the South. 

New stands of pine and hardwood often develop 

after timber harvests. 

Almost 11 percent of all pine-hardwood stands, or 

3.4 million acres, are planted (table 3). In these 

stands, the pine component has been planted but 

the hardwood stocking exceeds that of the pine. 

Planting efforts contribute 28 percent of the current 

sapling-seedl ing stands, but are relatively minor 

component of the more mature stands. Planted 

sapling-seedling stands are concentrated on forest 

industry land; nearly three-fifths of these young 

pine-hardwood stands on forest industry are 

planted. Sawtimber stands dominate the pinehardwood resource on public and other private 

ownerships, whereas sapling-seedling stands 

dominate the type on forest industry land. 

Pine-hardwood stands are found mainly on sites 

with average or better productive potential (figure 

5). FIA measures of site quality are based on potential yields in cubic feet per acre of mean annual 

growth at the culmination of increment in fully stocked natural stands. Average sites (50-84 cubic feet 

per acre per year) make up 39 percent of the pinehardwood acreage. Poor sites (20-49 cubic feet 

per year) account for only 13 percent, and good 

sites (more than 85 cubic feet per acre per year) 

make up the remaining 48 percent. 

These potential yields usually are not realized 

across large areas like entire States. This observation appears to be especially true for pinehardwood stands. Throughout the five 

Million acres 

- 20-49 50-84 85-1161 120* 

Cu. ft./acre/year 

Figure 5.--Area of pine-hardwood forest type in the 

Eastern United States, by productivity class. 
Southeastern States, net annual growth in pinehardwood stands currently averages only 50 cubic 

feet per acre. Pine ecosystems tend to be more 

productive, averaging more than 70 cubic feet per 

acre annually. Part of the reason for low productivity of pine-hardwood stands is that conditions are 

less than desirable in these stands. Partial harvests 

(otten high-grading) created many of the pinehardwood stands that now exist. The cutting often 

left a poorly stocked residual stand that hampers 

the establishment and vigorous development of 

reproduction. Common treatment needs are displayed in figure 6. About 18 percent of all pinehardwood stands in the East are so poorly stocked 

that a manageable stand does not exist. A new 

stand should be established through an appropriate 

stand regeneration method. Another 19 percent 

need intermediate treatments such as release cuttings to permit crop trees to develop unhampered 

by older residuals and culls. 

INVENTORY VOLUME 

The 31 '2 million acres classed as pine-hardwood 

contain 33.7 billion cubic feet of growing stock 

(table 4). About 55 percent of this standing inventory is softwood and 45 percent is hardwood. This 

total inventory is equivalent to 1,080 cubic feet per 

acre. Consistent with the acreage distribution, 

about 55 percent sf the volume is in the South. 

The amount pine-hardwood stands contribute to 

total inventory volumes varies by region. Pinehardwood stands contain 16 percent of the South's 

Harvest -2 

None 

54% 

Figure 6.--Percentage distribution of pine- hardwood 

acreage in the Eastern United States, by treatment 

opportunity. 

softwood inventory and 10 percent of the 

hardwood. In the North, these proportions stand at 

4 percent for softwood and only 2 percent for 

hardwood. Under a more encompassing definition 

of pine-hardwood type, the contributions of these 

stands to regional invent~fy totals would increase. 

Pine-hardwood stands are diverse in species cornposition. A complete listing of species is too long 

for this discussion, but major species and species 

groups are listed, along with associated inventory 

volumes for the two major regions (table 5). In the 

North, white pine is the dominant softwood in pinehardwood stands with 0.9 billion cubic feet of 

Table 4.--volume of growing stock on timberland in the Eastern United States, 

by region, species group, and stand type 

Region and All Pine-hardwood Other 

species group types type types 

Billion cubic feet 

North : 

Softwood 

Hardwood 

Total 

South: 

Softwood 

Hardwood 

Total 

Eastern United States: 

Softwood 151.7 18.6 133.1 

Hardwood 273.8 15.1 258.7 

Total 425 5 33.7 391 . 8 
Table 5.--Volume of growing stock in pine-hardwood stands in the Eastern 

United States, by species and region 

Species Total North South 

Billion cubic feet 

Softwood : 

Longleaf-slash pine 1.8 0 1.8 

Loblolly-shortleaf pine 12.5 0.4 12.1 

Other yellow pine 2.0 0.4 1.6 

White-red pine 1.3 03 0.4 

Other softwood 1.0 0.4 0.6 

Total 18.6 2.1 16.5 

Hardwood : 

Select oak 3.0 1.0 2.0 

Other oak 50 0.5 4 5 

Hickory 1.0 0.3 0.7 

Soft maple 0.8 0.3 0.5 

Swee tgum 2.1 0.1 2.0 

Tupelo-blackgum 0.7 0 0 7 

Yellow-poplar 1.1 0.1 1.0 

Other hardwood 1.4 0.5 0.9 

Total 15.1 2.8 12.3 

All species 33.7 4. 9 28.8 

volume, or 44 percent of all softwood inventory in in the North. Soft maples (primarily red maple) are 

these stands. The remainder is equally divided be- the most common soft textured hardwood species. 

tween the loblolly-shortleaf group, other yellow 

pines (primarily Virginia and pitch pine), and a 

group of other softwoods (primarily eastern redcedar, hemlock, spruce, and fir). In the South, the 

loblolly-shortleaf group accounts for nearly threefourths of the softwood total. 

Oak species tend to dominate the hardwood component of the pine-hardwood resource throughout 

the Eastern United States. In the South, "other oak 

species" account for 4.5 billion cubic feet, or 37 percent of the hardwood total. This group includes 

laurel, witlow, water, southern red, scarlet, chestnut 

oak, and numerous less common oak species. 

Select oaks, primarily white oak and northern red 

oak, account for 2.0 billion cubic feet, or 16 percent 

of the hardwood total in the South. Significant 

volumes of sweetgum, blackgum/tupelo, and yellowpoplar also exist in pine-hardwood stands in the 

South. 

In the North, hardwood volume includes a noticeably higher proportion of select oaks. Select oaks account for 36 percent of the hardwood inventory in 

pine-hardwood stands in this region. The sweetgumiblackgum/yellow-poplar component is minor 

In the South, the softwood component in pinehardwood stands tends to be larger than the 

hardwoods (figure 7a). A higher proportion of the 

softwood volume exists in the 12-inch and larger 

d. b. h. classes than does the hardwood component. 

Hardwoods are more concentrated in the 6-, 8-, 

and 1 0-inch diameter classes. Softwood and 

hardwood distributions across all forest types in the 

South show just the opposite picture (figure 7b). 

Generally, the softwoods are smaller than the 

hardwoods. The concentration of hardwoods in the 

smaller diameter classes reflects the manner in 

which many of the current pine-hardwood stands 

were created. Partial harvesting in pine stands 

during previous decades has promoted the growth 

and development of understory and midstory 

hardwoods. Even though the hardwood component of these disturbed stands has thrived, the 

stems are smaller than those of most residual pines. 

From a timber supply standpoint, the larger pines 

in pine-hardwood stands will become a more and 

more attractive source of large diameter sawtim ber 

as pine plantations account for more of regional 

pine inventories (US. Department of Agriculture 

1 988 b) . 
(a) Pine-hardwood Stands 

Percent sf total 

20r 

of twood ----- 

18 

188) 

(b) All Stands 

Percent al total 2or 

12 14 l6 

1.h. class (inches) 

Figure ?.--Percentage distribution of growing-stock 

volume in the South, by species group and d.b.h. 

class. 

FUTURE DIRECTIONS 

What changes in the pine-hardwood resource can 

be expected in the future? Will there be more 

mixed conditions or fewer? Will mixed stands be 

older or younger? Will they contain high-quality timber needed to help meet future demands? We do 

not have a crystal ball to provide the answers. We 

can, however, develop likely scenarios from what 

we know about the present resource, how it came 

into existence, and how it has been changing. 

During the past two decades, acreage of pinehardwood forest type in the Eastern United States 

has declined by 1 1 percent, dropping from 35 million acres in 1990 to the present 31 million acres 

(figure 8). In the Noflh, acreage has remained at a 

constant 4 million acres, All of the decline has occurred in the South, especially in the latest decade. 

Southern pine plantation acreage has increased 

during the past two decades, while the extent of 

both natural pine and pine-hardwood types has 

dropped (US. Department of Agriculture 1988b). 

Losses to nonforest land uses also have been a 

major contributing factor in these reductions. 

A recent regional and national assessment of forest 

resources provided projections of timberland area 

for each of the major forest types3 (U.S. Depattment 

of Agriculture 1 988 b) . These project ions suggest 

that the recent trends in pine-hardwood acreage in 

the Eastern United States will continue, at least for 

the near future. By the year 2000, pine-hardwood 

acreage is projected to drop another 4 million 

acres, with the bulk of the loss occurring in the 

South. Much of the reduction is projected for forest 

industry land. Thereafter, small declines are 

projected to 2040. 

Driving Forces 

The model used to estimate prospective change in 

area by forest type is based on a wealth of 

economic inputs, plus data on stand treatment and 

disturbance rates (Alig 1984). The rates of treatment by type are linked to probabilities that the 

treated stands will shift to another type or remain in 

the original type. Treatment and disturbance data, 

and resulting shift rates, were developed from FIA 

broad-scale inventory data. The repetitive nature of 

these forest inventories makes them a unique data 

source to quantify regional change in forest types. 

These inventories also help identify treatments and 

disturbances that play major roles in creating and 

diverting pine-hardwood stands. We should examine these forces since they will probably shape 

tomorrow's pine-hardwood resource unless we alter 

and control them in a positive manner. 

Three major forces tend to create pine-hardwood 

stands: (1) partial harvests, (2) stand establishment 

or regeneration, and (3) successional change or 

stand development. Partial harvests include a number of kinds of timber cuttings, but all too often the 

cutting is best described as hig h-grading. Partial 

harvests in pine stands create an instant pinehardwood type when the softwood stocking is 

reduced below that of the hardwood component. 

After more complete harvests, the regeneration that 

develops, or is planted, often results in a mixed condition. Natural regeneration on former pine sites 

results in a pine-hardwood condition more often 

than after planting. The third factor, natural succession, reflects the natural course of stand development. In established pine stands, natural 

3~lig, Ralph J.; Murray, Brian; Hohenstein, William [and 

others]. Changes in timberland area in the United States 

by state and ownership, 1952-1987, with projections to 

2040. Gen. Tech. Rep, WO- . Washington, DC: US. 

Department of Agriculture, Forest Service (in process). 
MILLION ACRES 

40 ----- 

0 

1970 1975 1980 1985 

YEAR 

++-+ EAST Ek-f++! NORTH SOUTH 

Figure 8.--Area of pine-hardwood forest type in the 

Eastern United States, by region, 1970-89. 

succession moves stands from pine to hardwood. 

As pine stands mature, the hardwood component 

assumes greater dominance and a pine-hardwood 

type eventually results. In very young stands with 

less than 25 percent pine, succession can favor the 

pines and move stands from a hardwood to a pinehardwood type. 

Three major factors divert acres from pinehardwood: (1) stand harvests, (2) successional 

change or stand development, and (3) timberland 

clearing. When a pine-hardwood stand is completel y or partially harvested, conversion to another type 

usual1 y results. Sometimes the conversion is 

planned, such as when a pine plantation is established after a harvest. In many cases, however, the 

natural course of events is accepted. Successional 

change or stand development also plays an important role in losses of pine-hardwood in both young 

and older stands. In the more mature pinehardwood stands, the successional forces continue 

until the hardwood stocking is high enough to move 

the stand to a hardwood type. In young stands, 

changes can occur more rapidly. Newly established stands often begin as pine-hardwood mixtures. As these young stands develop, the pines 

often assume dominance and the stand takes on a 

pine type. Such changes during the early years of' 

stand development are more common in planted 

mixed stands than in natural mixed stands4. The 

clearing of pine-hardwood stands is also an obvious and major factor in losses of mixed acreage. 

Obviously, human activity and naturai Forces cause 

both gains and losses to the pins-hardwood 

resource over time. Figure 9 shows the net: effect of 

final harvest, partial harvest, and '"0 cu8iatgi"on the 

annual change in pine-hardwood acreage in the 

South. The "no cming'kategory inc!udes all areas 

where no activity was recorded plus all forms of 

minor human adivity and natural changes. The net 

eBect of timber cming (final and parlial harvests) is 

to maintain the base acreage in pine-hardwmd 

stands--annual additions to pine-hardwood offset 

48ata on fils at the S~uthclastern Forest hperiment Station, 

Forest Inventory and Analysis, 
Pine- hard wood Gains From 

Other Forest Types 

Pine-hardwood Losses To 

Other Forest Types 

Tbusand acres 

lrnO r 

BOO 800 ........................... ........................... ........................... ........................... ........................... .......................... 000 600 .......................... 

.......................... ..............*..,.....t. 

400 400 

200 200 

0 - 0 

Final harveat Parti J harvert No cutting Final harwet Partial harveet No cutting 

Hardwood a Natural pine a Pine planlation Hardwood Natural pine a Plno plantation 

Figure 9.--Annual gains and losses of pinehardwood acreage in the South, by type of treatment. Data developed from all States in the South 

except Tennessee. Most recent remeasurement 

period used--length ranges from 8 to 10 years. 

annual diversions to other types. Additions that CONCLUSIONS 

result from timber cutting come largely from natural Three conclusions about the pine-hardwood 

pine stands. On the loss side, harvested pine- resource can be drawn: 

hardwood stands usually shift to hardwood types. 

Almost 28 percent of pine-hardwood stands moving 

to another type after a final harvest were converted 

to pine plantations. The "no cutting" category accounts for higher annual gains and losses; the net 

result is a 173,000 acre loss of pine-hardwood type 

annually. A surprisingly high proportion of the 

gains to pine-hardwood in this group were formerly 

hardwood types, suggesting that young hardwood 

stands often develop into mixed stands. For losses, 

most pine-hardwood stands that move to other 

types in the absence of cutting go to a pine designation, either natural or planted. 

Regionally, pine-hardwood mixtures can be viewed 

as dynamic and transitory. With time, stands move 

into and out of the pine-hardwood classification 

very easily and often. In part, the high rate of 

change for this resource can be attributed to the 

range of softwood stocking used in defining it. The 

real driving force, however, is the human activity 

that has altered and speeded the natural tendency 

of these stands to change. 

(1) Recent changes in the resource and the factors 

causing these changes suggest further short-term 

reductions in pine-hardwood acreage in the South. 

Two major factors influencing the prospective drop 

include continued favoring of pine plantations over 

natural stands and the clearing of pine-hardwood 

stands for nonforest uses. Mixed stands of pine 

and hardwood will continue to be a major component of forests in the Eastern United States because human activities and nature create mixed 

stands. 

(2) The pine-hardwood resource will probably become younger. High harvest rates in the South will 

continue to create mixed sapling-seedling stands. 

Younger stands could result in a pine-hardwood 

resource that is even more transitory than in the 

past. 

(3) The quality of tomorrow's pine-hardwood 

resource will be determined by the collective actions of all of us. The resource we have today has 

been shaped profoundly by human intervention 

and activities. Some human influences have been 

positive, but all too often pine-hardwood stands are 

the product of poor pine management. The quality 

of tomorrow's resource is something we all have the 

opportunity to impact in a positive way. The growing awareness that pine-hardwood stands can be 

managed to maximize the benefits they offer is an 

encouraging step in that direction. 
LITERATURE CITED 

Alig, Ralph J. 1984. Modeling acreage changes in 

forest ownerships and cover types in the 

Southeast. Res. Pap. RM-260. Fort Collins, CO: 

U.S. Department of Agriculture, Forest Service, 

Rocky Mountain Forest and Range Experiment 

Station. 14 pp. 

Garrison, George A.; Bjudstad, Ardeli J.; Duncan, 

Don A. [and others]. 1977. Vegetation and environmental features of forest and range 

ecosystems. Agric. Handb. 475. Washington, DC: 

U .S. Department of Agriculture, Forest Service, 

68 PP. 

McWilliams, William H.; Birdsey, Richard A. 1984. 

Loblolly pine ecosystem of the Midsouth. pp. 41 - 58. In: Proceedings of the symposium on the 

loblolly pine ecosystem (West Region); 1983 

March 20-23; Jackson, MS. Mississippi State: Mississippi State University Cooperative Extension. 

McWilliams, William H.; Sheff ield, Raymond M.; 

Hansen, Mark H. [and others]. 1986. The 

shortleaf pine resource. pp. 9-23. In: Proceedings 

of the symposium on the shortleaf pine ecosystem; 1986 March 31 -April 2; Little Rock, AR. 

[Available from Arkansas Cooperative Extension 

Service, P.O. Box 3468, UAM, Monticello, AR 

71 6551 

Phillips, Douglas R.; Abercrombie, James A., Jr. 

1987. Pine hardwood mixtures- a new concept in 

regeneration. Southern Journal Applied Forestry 

11(4):192-197. 

Sheffield, Raymond M.; Knight, Herbert A. 1983. 

Loblolly pine resource-Southeast region. pp. 7- 

24. In: Proceedings of the symposium on the 

loblolly pine ecosystem (East Region); 1982 

December 8-10; Raleigh, NC. Raleigh, NC: 

School of Forest Resources, North Carolina State 

University. 

Sheffield, R.M.; Knight, H.A.; WlcClure, J.P. 1983. 

The slash pine resource. pp. 4-23. In: The 

managed slash pine ecosystem; 1981 June 9-1 1 ; 

Gainesville, FL. Gainesville, FL: School of Forest 

Aesources and Conservation, University of 

Florida. 

U.S. Department of Agriculture, Forest Service. 

1988a. An analysis of the timber situation in the 

United States: 1989-2040. Part I: The current 

resource and use situation. [Draft]. Washington, 

DC. 281 pp. and appendices. 

U.S. Department of Agriculture, Forest Service. 

1988b. The South's fourth forest: alternatives for 

the future. For. Resour. Rep. 24. Washington, DC. 

512 pp. 
ARE OUR TRADITIONAL ATTITUDES RESTRICTING 

FORESTRY MANAGEMENT OPTIONS? 

Robert J. ~entz,' Daniel H. ~irns,' and Peter J. lnce3 

. - f nvironmental influences and marketiprocessing trends are changing the 

future of forestry in the South. Forest management options must be broadened beyond 

the current mindset to achieve future environmental and economic goals. 

Pineihardwood mixtures on appropriate sites is a positive response to future tiends. 

INTRODUCTION 

Is it reasonable to grow, harvest, and regenerate 

pine and hardwoods in mixtures? For centuries, 

trees have grown this way without any management. The question is, "Can these mixtures be 

managed to meet the challenging environmental 

and economic needs of tomorrow's markets and 

society?" 

Will foresters have time to study, debate, and test 

options or wili the pineihardwood mixtures or other 

systems be forced upon us without solid research? 

The answer isn't clear but let's explore some possibilities facing us today and tomorrow. Two major 

trends are shaping this management scheme: environmental influences and changing 

mar kets/processes. 

ENVIRONMENTAL INFLUENCES 

Southern forest managers' attention is being slightly 

diverted to address foreign or less popular concerns such as biological diversity, uneven-aged 

management and pine/hardwood mixtures. Public 

attitudes and special interests are raising this awareness. Some examples are public land pressures, 

environmental organization influx, hunting leases, 

nongame wildlife uses, landowner objectives and 

public opinion. 

PUBLIC LAND PRESSURES 

Environmental concerns dominated the national 

forest land management planning efforts in the 

South. In January 1988, 95 percent of the active issues under negotiation involved environmental issues. Interest was keen on the impact of timber 

Director, Cooperative Forestry, USDA, Forest Service 

Southern Region, Atlanta, GA; 

* Hardwood Specialist, USDA Forest Service, Southern 

Region, Atlanta, GA.; 

Research Forester, USDA Forest Service. Forest 

Products Laboratory, Madison, WI. 

management on wildlife (about 50 percent). Many 

of these interests prefer eliminating intensive plantation management. They would increase the 

hardwood component to avoid a perceived pine 

monoculture. Comments imply a reduced harvest 

on public lands, with the private lands to pick up 

the shift in supply. 

HUNTING LEASES AND WILDLIFE INTEREST. 

Hunting leases are increasing on private lands in 

the South (1 981). Smith reports that 26 percent of 

all nonindustrial private forest lands are leased to 

hunting clubs or require a fee to hunt. Similarly, 29 

percent of industry lands are leased. Those percentages increased to 33 percent by 1985, as landowners gained higher fees and achieved other 

benefits such as road maintenance from such contracts (Marion and others, 1988). 

Hunting rates can run $90 per day for deer hunting 

or $400 per day for quail. Best habitat, with high 

numbers of animals and demand near populated 

areas yield higher prices. Leases are expected to 

increase for hunting and nonconsumptive uses 

such as birdwatching, camping, and hiking. 

Hardwoods can enhance habitat diversity for both 

game and nongame species, and potentially yield 

higher lease fees. 

NONGAME WlLDLlF E USES 

Birdwatching is another factor shaping public 

opinion. In 1987, Americans spent $1 .l billion on 

bird feed, according to Harmon (1 988). In 1985, 

82.5 million people--slightly more than one-t hird of 

our population fed birds. They spent $239 million 

on feeders, nest boxes and birdbaths. Nearly $375 

million went for binoculars and spotting scopes. 

The trend for this activity is dramatically upward. 

Let these people (many urbanites) "perceive" that 

forest management has done anything to adversely 

affect their feathered friends and watch what happens! 
LANDOWNER OBJECTIVES 

Landowner studies show that timber for profit is not 

the only motivator for landowners. Royer (1987) 

asked landowners to rate several factors on a scale 

of 1 -1 0 (1 0 = high) Forty-nine percent rated 7 ifor timber growing as a source of income. Similarly, 44 percent rated 7 + for recreational opportunity 

and hunting. 

Fecso and others (1982) asked landowners who harvested timber, "Why do you own the land?'' The 

results were: growing wood for sale (78 percent), 

recreation and hunting (30 percent), esthetics (1 9 

percent), inherited the land (51 percent), and plan 

to pass land on to heirs (53 percent). Over one-half 

of the owners inherited the land and plan to pass it 

on to their heirs. 

Haymond (1988) surveyed NIPF opinion leaders to 

determine the primary source of satisfaction in 

owning forest land in South Carolina. The primary 

reasons included pride of ownership and personal 

satisfaction, stewardship, best land use and conservation, privacy, recreation, pleasure and family. 

Lifestyle enhancement was primary to 52 percent of 

the respondents. Forty-eight percent chose 

economics and timber as the primary reason. 

These studies show a preference for land 

stewardship, hunting, wildlife, and esthetics, as well 

as timber, in NIPF forest management options. 

These are the landowners who control 72 percent of 

our forest land base in the South. Pine/hardwoods 

in mixtures could enhance these values. Are we 

giving them that option on appropriate sites? 

PUBLIC OPINION 

An industry public opinion survey by the American 

Forest Institute (1 986) and southern forestry associat ions surfaces conflicting messages. Sixtyseven percent agree that industry does a good job 

of conserving natural resources. Seventy one percent agree that industry grows and harvests trees in 

ways that are environmentally sound. Yet, only 29 

percent agree that owners of forest land can be 

trusted to protect the beauty of forest lands and the 

quality of the environment without regulation. 

ENVIRONMENTAL INFLUENCES SUMMARY 

Environmental concerns are increasing in importance to land managers, private landowners, organized groups and the general public. Wildlife, 

esthetics and stewardship are key public and landowner concerns. These concerns can be turned 

into assets through increased diversity. 

Environmental pressure is currently directed to 

public lands, but private land challenges are not far 

behind. We walk a fine line of public support. 

Forest managers must improve the balance between environmental quality and economic development or the public will call our hand and make 

changes we don't need or want. 

Much of our research. education and day-to-day 

operations emphasize maximum wood production 

(generally pine production). While we try to grow 

every cubic foot or ton of wcod we can out of the 

landscape, landowners are saying stewardship and 

other resource values are equally or more important. Are our attitudes blinding us to other forest 

management options? 

CHANGING MARKETS AND PROCESSES 

Change in wood products and markets is the 

second major influence affecting pinei hardwood 

management options. Improved processing and 

wood for energy, and resultant hardwood stumpage 

prices will have the greatest impact on 

pine/hardwood use in the South. 

IMPROVED PROCESSING 

In the pulp and paper industry, improved pressing 

technology, including wide nip and high impact 

presszs, are being installed. Many milis in the 

South have installed this processing improvement 

since 1980. The result is that some kraft linerboard 

mills have been able to shift from less than 10 percent hardwood to 30 percent or more hardwood in 

fiber furnish. 

Press drying or impulse drying in the future means 

even more hardwood in linerboard and newsprint. 

The press-dried paperma king process developed 

by USDA1s Forest Products Laboratory can use up 

to 100 percent hardwoods to produce linerboard 

with improved strength. Here is a process using 

hardwoods, when compared to existing technology, 

can save on capital costs, energy, raw materials (by 

using hardwoods with lower current stumpage 

value) and at the same time increase yields from 

raw materials and reduce effluent (Ince 1983). 

The rising demand for other paper and board 

products will involve the use of higher percentages 

of hardwoods. Substantial increases in demand 

are expected for printing and writing paper, tissue, 

and semichemical board (Ince and others, "1987 j. 

See figures 1, 2, 3, 4 and 5. Greater demand for 

these products means more use of hardwood since 

hardwoods are already heavily used in these 

materials. 

Based upon a consensus of pulp and paper industry experts, the study projects major trends that. 

will positively impact the use of hardwoods. For example: 
Figure I.-Praductlon of Prlntlng & Wrntlng Paper 

Trend & Brojsctlon, 1960-2640 

Figure 3.--Semichemical Board - Production 

South 

Figures 2.--Printing & Writing Paper 

Hardwood Use in the South 

9 1 .More hardwood fiber will be used in printing 

and writing paper, as demand is expected to 

rise substantially. 

e 2. More use of short-fiber furnish in linerboard: 

New product market demands for stronger 

boxes with compression strength and printability is achievable with more hardwood fiber. 

1980 1990 2000 2010 2020 2030 2040 

Yea: 

FIgurs 4.-Production of TIssus 

Trend and Projection, 1960.2040 

Better sheet additives, particularly strength-irnproving additives, and improved pressing technology, translates into general prospects for 

more use of hardwoods in kraft linerboard. 

03.Further replacement of groundwood pulp by 

modern mechanical pulping methods such as 

thermomechanical and chemithermomechanical pulping is anticipated. 
Figure 5.--Southern Pulpwood Prices 

Proj., 1987-2035 Sfwd. & Hdwd. 

a- Hardwoods 

--+- Softwoods 

Other research is underway to shape and mold 

paper and wood fiber. This opens the door for a 

whole new generation of wood products. An example is Temple Inland, Inc., moulded microwave 

dishes. The Forest Products Laboratory is experimenting with a new molded fiber product called 

spaceboard. 

WOOD FOR ENERGY 

Each day we hear of new mills being constructed to 

produce oriented strand board or flakeboard, which 

use a component of hardwoods. In addition, 

markets for quality hardwoods seems unlimited. 

Together, these processes and markets add up to 

increased use of hardwoods. 

Wood for energy has potential. Technology for 

wood combustion and feeder systems is on the 

shelf and could easily be adopted if fossil fuel prices 

rise slightly. Any interruption of our oil imports, 

(which have gradually increased) will cause 

shortages, increased prices, and the use of more 

wood for fuel. Even with a lagging wood-energy 

market, more wood is consumed as fuel in the 

United States today than for all other uses combined. 

HARDWOOD STUMPAGE 

Pulp and paper processing along the southern 

coasts has shifted from mostly pine to a higher percentage of hardwoods, some as much as 80 percent hardwood. Two reasons for this are cheaper 

stumpage price for hardwoods and an increasing 

market for high quality white paper (printing and 

writing paper). lndustry is adjusting their machines 

to accommodate hardwoods rather than adjusting 

the iandscape to pine. Some localized shortages of 

hardwoods have occurred and have brought 

hardwood pulpwood stumpage prices within $2 of, 

or even exceeded, pine prices. 

The question behind most management options is, 

"How can the forest or landowner achieve the 

greatest benefit in the future?" This is usually 

judged by foresters to mean maximum timber 

values. The timber prices are measured by current 

and projected timber prices. These prices project a 

pine increase of 4 percent per year while hardwood 

stumpage remain static or a smaller increase than 

pine. Yet, with trends before us, hardwood prices 

are expected to increase at a faster rate than the 

price of pine. Accordingly, a leveling eFfect is 

forecast by 2010 (figure 5). Perhaps we need to 

rethink our economics and the advice given based 

upon past assumptions. This trend of increased 

hardwood use with resultant higher hardwood 

prices is expected to continue through 2035 when 

hardwood prices could exceed those for pine 

pulpwood. 

MARKET INFLUENCE SUMMARY 

These marketing and processing trends strong1 y 

suggest that industries and landowners will diversify 

their markets. Industry will diversify their raw 

materials and product mix as landowners diversify 

their management and production of raw materials. 

The increased use of hardwoods and a gradual 

leveling trend between pine and hardwood 

stumpage prices will stimulate this diversification, 

as well as economic development. Are our 

southern pine attitudes restricting forest management options? 

3-8 TEST 

Based upon the trends we just discussed, it appears that every option for a pine/hardwsod mixture site should be given the "3-B Teest." This 

3-dimensional test will review the management options for future environmental 

Environmental is a test For a variety of 

plants and ani g and growing together to 

satisfy wildlife, esthetics and stewardship concerns. 

Market product "iests the raw 

materials produced against current and future 
markets, keeping an eye on new products and 

processes looming on the horizon. 

Overall economic tests for jobs, income and new business stimulated through forest 

management options. Major options are not just for 

timber, but also for hunting, bird-watching and 

other primary and secondary spinoffs from future 

forests. 

Pineihardwood mixtures on appropriate sites 

should certainly be a viable option against these 

tests. The test would also have to be within the 

framework of the landowners' objectives. 

This 3-0 Test will show that all our pine decisions in 

the past are not bad and that softwood management is not on the way out. Our past decisions 

have sewed us well. Basically, our southern pine attitudes are not bad, but perhaps they need some 

fine tuning. The questions we must ask is: "Will 

today's decisions serve us well in the future?" Are 

we ready ts risk opening new frontiers in pins 

hardwood management that are less costly, work 

with nature to provide many environmental spinoffs 

yet potentially produce a little less wood. 

UNLOCK OUR MINDS 

How do we change thinking to broaden forest 

management options? First, reach landowners 

I before the timber harvest decision is made. Then 

you should have options available. 

Second, seek landowner objectives and don't listen 

selectively for a pine option or maximum timber 

production option. This means top level officials in 

your organization must have more than maximum 

timber profit on their agenda. The pine/hardwood 

option could mean a higher rate of return because 

of lower front-end costs and other resource 

economic benefits. 

Third, remember the 3-D test--options for increased 

ecological diversity, product diversification, and 

overall economic development. Where it blends 

with landowner objectives and site conditions, try 

options other than pure pine. 

Other thoughts are: 

-Consider the hardwood component first because 

it will usually be regenerated naturally. Then consider supplemental planting or natural regeneration 

with pine. 

-On regeneration cuts get total utilization to 

reduce regeneration costs and eliminate highgrading once and for all. 

-Stimulate new or change existing incentives, 

programs, pilot projects and demonstrations to enhance pine/hardwsod miaures on proper sites. 

-Accelerate research and technology transfer that 

improves our knowledge and management of 

pineihardwood mixtures and creates new processes and markets for pineihardwood use. 

So now we stand on the threshold of continuing 

down the primarily pine management path or exploring a new opportunity on appropriate sites and 

managing for pineihardwood mixtures. Will our 

traditional pine attitudes restrict forest management 

options? The answer is up to you. 

LITERATURE CITED 

American Forest Institute. 1986. Public opinion survey. Washington: Technical Notes. The 

American Forest Council and Southern Forestry 

Associations. p. 19. 

Fecso, R. S.; Kaiser, H. F.; Royer, J. P.; Weiderhamer, M. 1982. Management practices and 

reforestation decisions for hawssting southern 

pinelands. SRS staff report No. AGES821 230. 

Washington: USDA Statistical Rsporting Service. 

74 p. 

Harmon, John. 1988. Americans are going to the 

birds. News article. The Atlanta Journal. p A22 

Haymond, Jacqueline L 1988. MI PF Bpinjon 

Leaders: What do they want? Journal of 

Forestry, April, 30-34 pp. 

Ince, Peter J. 1983. Process economics of press 

drying for kraft linerboard. Madison, WI. Extended abstract of a paper presented at Press 

Dry Conference 1983. USDA Forest Products 

Laboratory. 6 p. 

lnce, Peter J.; Burbak, Irene; Howard, James L. 

1987. Pulpwood model--data, assumptions, 

preliminary results review draft. Madison, WI. 

USDA, Forest Products Laboratory. 63 p. 

Marion, Wayne R.; Gates, Cyndi A., 1988. Hunting 

lease arrangements in Florida and the Southeast. 

Circular 793. Gainesville, FL. Florida Cooperative Extension Service, Institute of Food and 

Agricultural Services, University of Florida. 19 p. 

Royer, Jack P., 1987. Use and effects of the 

reforestation tax incent ives and cost sharing in 

the South. Durham, N.C., Duke University. p 6- 

20. 

Smith, George E.; Palermo, Ray; Evans, Ray. 1981. 

Forest Landowners: An assessment of hunting 

and wildlife planning on forest lands in the 

southeast. Technical Report of a Study Group appointed by the Forest Resources Committee. 

Southeastern Association of Fish and Wildlife 

Agencies. 7 p. 
Moderators: 

M. Boyd Edwards, Jr. 

Southeastern Forest Experiment Station 

USDA Forest Service 

David Wm. Smith 

Department of Forestry 

Virginia Polytechnic Institute and State University 

Klaus Steinbeck 

School of Forest Resources 

University of Georgia 

EVOLUTION OF FOREST TYPES IN THE SOUTHEAST 

-Two separate factors are invoived rn triack~ng the evolution of forest types rn the 

Southeast - 1) the e\iolution of the species that comprise them and 2] the debeispment of the forest 

assoc~atrons that we ~dentify as cover types Oi the two taxoqornic that camprise 

Southeastern forests (gymnosperms and angiosperms) the gymnosperms are the more primitive 

datrng from the Palsozolc era (over 300 mlliions years ago) wh4e Ibs angiosperms date to the 

Ea~iy Ctetaeesus Period (120 rn~ilton years ago) ir; both grotips most of the species found in 

Southeastern forests today evolved during the Cenozoic Era the last 65 mrl'ion years) The 

present forest associattons (forest types: found in the sodtbeast developed since the last ice age 

largely during the Holocene Epoch (last 10,000 years) and they are stir/ changing Afitkroptagen~c 

influences were and st111 are important vectors In drrecrlng these char4ges 

INTRODUCTION 

Among the more intriguing puzzles that scientific inquiry deals with is the question of how the "here 

and now' came to be. When the subject in question 

is the forest cover types of a region, ferreting out 

their origin and the evolutionary road to the present 

is of more than academic interest. 

Understanding these pathways and the vectors that 

drove the processes should be the base on which 

sound forest management strategies are developed. 

The numerous environmental groups who are today 

insisting that forest managers return our forests to 

their '"original" condition is further stimulus for gaining this understanding. 

Once the evolution of the present forest cover of a 

region is tracked, the opportunities for keeping it in 

(returning it to) its "original" condition can be 

evaluated. Apparent in this process will be the 

recognition that forests are dynamic - they are and 

always have been changing through time, a fact 

that man's short life span often conceals. 

The present forest types of Southeastern U.S. are 

composed of members of two taxonomic groups - 

gymnosperms (conifers) and angiosperms 

(hardwoods), mixtures of which are the primary 

focus of this symposium. The silvical characteristics 

sf the species that are broadly distributed over the 

Southeast (pines and hardwoods) are such that 

pines usually become established in pure stands following major disturbances (pioneer species) white 

most hardwoods are later successional species that 

became established in various miMures. The pinehardwood mixture is characteristically a mid-%era/ 

stage that is ephemeral on a given site. It is maintained in a changing landscape mosaic where scartered disturbances re-initiate succession in a 

stochastic manner. 

' ~rofesssr, Department of Forestry, Wildlife & F~sher~es 

Unrversrty of Tennessee, Knoxv~lle, TN 37901 -1 071 

Two separate fadors are involved in gaining an understanding of the origin sf these associations. First 

is the evolution of the species that comprise the 

forests, and second is "re ddevc?lhapmenr of the forest 

associations that are identified as cover types. 

These developments were largely independent of 

each ohher with most of the existing species having 

evolved earlier in the present geologic era 

(Cenozoic) while the present forest associations are 

more near1 y "current events. ' 

SPECIES EVOLUT193N 

Understanding the evsiutionary pathways to the 

species comprising the present forest types of the 

Southeast poses a basic question - where do we 

begin? Assuming that the usual answer "in the 

beginning" is wprepriate, scientists today are in 

general agreement that the seQing for the evstutionary processes on Eafl-lch came into being some 4.6 

billion years ago (table 1). As early as 3.8 billion 

years ago fossil evidence confirms that primitive 

marine piants had evsived: bl @-green algae, baeteria, fungus-like organisms and green algae, or 

Chlesrophyla, the probable precursors ts the 

Tracheopkyqes, the vascular plants that 'clot he" 

much of the land area of the Each today (Cooper 

and others 1986). 

More than 3 4 billion years was required for these 

original primitive life-forms to evolve into the vascular pfanis that could sui-dive on the drier upland 

regions 0%: the Earth, During the Silurian Period both 

plan& and animals moved from marine Po terrestrial 

environments By late Devonian vascular, seed-bearing plants had devei~ped, including the gymnosperms (Levin I 97%) 

During the Foliowing Mississippian and Pennsylvanian Periods (Carboniferous) broad areas of 

lowband forests (dominaNec8 by seed ferns) were 

buried under anaerobic csnditions lacking much sf 
Table 1. Geologic events of signifigance to the evolution of forest types 

in Southeastern U.S. 

Simple marine plants (blue-green algae, 

PRECAMBRIAN TIME colonial bacteria, fungus-like plants & 

green algae (=Chlorophyta).----------- 3,800 

'~illion Years Before Present 

28 

Significant Geologic Events Time 

(MYBP) 1 

Development of man. 0.01 

Most recent ice ages. 

2.5- 

Speciation with the development 5 

of most of the plant species 23 

known today. 37 

55 

Epochs 

Holocene 

Pleistocene 

Pliocene 

Miocene 

Oligocene 

Eocene 

Paleocene 

Eras 

C 

E 

N 

0 

Z 

0 

I 

C 

Periods 

Quaternary 

Tertiary 

M 

E 

S 

0 

z 

0 

I 

C 

Extinction of dinosaurs. 65- 

Cretaceous Origin and rapid development of 

the ANGIOSPERMS along with insects. 144- 

Jurassic Extinction of seed ferns. 

208- 

Triassic Origin of dinosaurs. 

245- Appalachian Revolution = Uplift of SE & 

Permian formation of Appalachian Mountains. 

I Formation of Pangaea completed. 286- 

P 

A 

L 

E 

0 

Z 

0 

I 

C 

Pennsylvanian Vast forests (largely sporophytes). 

(Upper Carboniferous) 320- Major coal-forming swamps. 

Mississippian Origin of conifers (including GYMNOSPERMS). 

(Lower Carboniferous) 3 60---- 

Devonian Seed ferns (first seed-bearing plants). 

Earliest forests. 408- 

Silurian Development of vascular plants. 

Earliest record of land plants. 438- 

Ordovician 

505- 

Cambrian Non-vascular, marine plant fossils 

(with reproductive spores). 

G7n- 
the atmospheric carbon (present as C02) into the 

extensive coal beds that are a primary energy 

source today. (Our current use of this stored energy 

is creating environmental probiems as this carbon 

is re-introduced into the atmosphere.) 

At the end of the Paleozoic Era (Permian Period) 

another geologic event of great significance to plant 

evolution in the Southeastern U.S. occurred - the 

Appalachian Revolution. This was the time when the 

Appalachian uplands were formed. Over the millennia these now old, deeply weathered uplands have 

been eroding, their sediments now form the broad, 

flat regions known as the Gulf and South Atlantic 

Coastal plains. Although the coastal regions have 

been alternately inundated and exposed during the 

several ice ages that have occurred since their formation, the higher uplands have been available for 

plant occupancy throughout the Mesozoic and 

Cenozoic eras - some 260 million years. 

During the middle of the Mesozoic Era (probably 

the Early Cretaceous Period - about 120 million 

years ago), angiosperms appeared in the 

landscape marking the next geologic event of signifigance in the evolution of Southeastern forest 

cover types. Not only did these, the flowering 

plants, appear suddenly in the fossil record, they 

flourished. By the end of the Mesozoic Era they 

were the most abundant land plants. This rapid 

proliferation is generally attributed to the concurrent 

evolutionary burst in insects, which were the 

primary pollinating vectors for the early flowering 

plants (such as magnolias). Today in Southeastern 

North America angiosperms comprise 95 percent of 

all living, terrestrial plants numbering over 250,000 

species compared to only 675 gymnosperms, 525 

of which are conifers (Harlow and others 1979). 

During the millennia since their appearance, angiosperms have vied with gymnosperms for 

dominance on the uplands of the Earth. While gymnosperms first occupied good sites, the greater 

com petit ive ability of angiosperms has general1 y 

relegated gymnosperems to poorer, harsher sites. 

With only a few exceptions (e.g. Pacific coastal 

forests), they are now dominant only in boreal 

forests, on poor, xeric soils and following disturbances that remove the more aggressive angiosperms. 

Not only are the gymnosperms more restricted in 

distribution, their taxonomic diversity is greatly 

reduced from their "heyday" in the early Mesozoic 

Era. [The competitive positions of these two groups 

in today's landscapes are somewhat ironic as the 

gymnosperms are in much greater demand by industry than are the angiosperms.] 

While the uplands of the Southeast were generally 

stable throughout the Mesozoic and Cenozoic Eras 

(in contrast to the general uplift and mountain building in western North America that marked these 

eras), changing climates and sea level fluctuations 

in the Southeast forced plant migrations that 

resulted in continued speciation (Cooper and 

others 1986). Most of the species found in the 

Southeast today were present when the last series 

of events that significantly influenced the forest 

cover types of Southeast occurred - the Pleistocene 

glacial events. 

In the 2.5 million years since the Quaternary Period 

began there have been at least 20 major ice 

episodes with each glacialiinterglacial cycle typically lasting 100,000 years. These advancing-retreating 

ice masses caused plant migrations that resulted in 

the extinction of over 50 percent of the pre-Pleistocene plant species found in Europe (Davis 1983). 

As a consequence of the essentially north-south 

orientation of the Appalachian Mountains migration 

corridors were open allowing plants to retreat 

before and advance after the various ice episodes 

(in contrast to the largely east-west orientation of 

mountains in Europe that forced plant extinctions 

rat her than allowing migration). The Wisconsinan 

Continental Glaciation, the last and largest ice 

episode of the Quaterrtary Period, peaked approximately 18,000 years ago when the continental 

ice mass extended southward to approximately the 

present positions of the Missouri and Ohio rivers 

(Delcourt and Delcourt 1 987). 

At this time the zone just south of the glacial front 

was tundra as were the higher elevations of the 

Southern Appalachians (in contrast to the claims of 

Braun (1 950) who saw them as a refuge for many of 

the plants that migrated northward as the glaciers 

retreated). The Southeast was a refuge for boreal, 

temperate deciduous and southeast evergreen 

forests during this time (Delcourt and Delcourt 

1985). Northern pines, spruces, fir and larch comprised the dominant forest cover as far south as the 

southern borders of Tennessee and North Carolina. 

Temperate deciduous and southeast evergreen 

species found refuge in the deeper South, pines 

and oak-hickory on the upper, dry sites, possibly associated with fire regimes, while the mixed 

mesophytic species were on moister, more fertile 

bottomlands. 

Northward migrations occurred rapidly as the ice 

mass retreated. Present woody plant distributions 

were largely "in placei' by the beginning of the 

Holocene - some 10,000 years ago. Essentially concomitant with this was the first evidence of human 

occupations in the region - approximately 1 2,000 
years ago (table 2). Thus "Man' (Horns 

was a part of the Southeastern environment during 

the time significant climatic changes \&ere driving 

major species migrations in the region. 

HUMAN IMPACTS ON FOREST EVOLUPlOH 

The extent of pre-Colurnbian human impacts on the 

landscapes of the Southeast has been largely sverlooked by both historians and ecologists 01: the 

many ways in which pre-historic man modified the 

forest, only through his use of fire &as his inftuence 

broad enough to srgnif~eantly affect the evolution of 

forest types. Fire has been used by mankind as a 

cultural tool for nearly 2 million years in Africa It 

was brought to America by the original settlers who 

crossed the land bridge (Beringla) that connected 

Alaska with Siberia during much of the Pleistocene. 

It wasiis a cultural tool that can quickly and easily 

modify large segments of the landscape, generally 

to the advantage of primitive human populations as 

it encouraged both the heiiophfles and herbivores 

that were primary food sources (Oakes 1939) 

The original human inhabitants sf the Southeast 

were the Paleo-Indians. Archeological evidence has 

established their presence in the region as early as 

12,000 years ago (Chapman i985j. At this time 

boreai and northern tree species were being displaced by southern taxa from that pofiisn of the 

Southeast north of 34' north latitude (approximately 

an east-west line through Atlanta, Georgia). The earliest of these inhabitants possibly contended with a 

periglacial climate (localized permafrost) as far 

south as an east-west line through Asheville, North 

Carolina (Keel 1 976). 

Paleo-Indians were largely hunter-gatherers whose 

use of fire to drive or trap large megafauna (large 

animals like buMalo and mastedon) is largely 

speculative. If, however, fire was used in this manner, subsistence needs would likely mean that fire 

was of frequent occurrence. Also, it is highly unlikely that their primitive tools enabled them "; contain 

their fires. Fuel loading and weather probably determined their extent and intensity. 

During this cultural period very rapid species adjustments were occurring throug hout the Southeast in 

response to the rapid climate warming that followed 

the Wisconsinan glacial episode (Delcoufi and Deleou~ 1987) Jack pine ( L ), currently a native of Eastern Canada, was then 

widespread throughout Tennessee, the Carolinas 

and northern Georgia. By the end of the Paleo-indian period it was rapidly disappearing From the 

Southeast. Today jack pine has a highiy serotinous 

cone indicating that fire was a primary factor 

'fixing' this feature in its genetic makeup. 

The Archaic Period (8500 to 1000 B.C. or 10,500 to 

3000 Before Present (8.P.j) was a time of human 

population grovv"ih and concentration in villages. 

The stone hearlhs, pottery and middens found in archaeological excavations indicate the evolution of a 

much more sophisticated lifestyle (Keel 1976). The 

widespread occurrence of sites of Archaic age 

throughout the Southeast and particularly in the 

Southern Appalachians suggest that these people 

were using the entire landscape, not just the fertile 

river bottsms (Keel 1976) They continued to be 

nomadic, however, which may account for the large 

number of sites identified. By the end of this period 

there are indications of a primative horticulture with 

squash and gourds as primary crops. Fire was the 

only feasible tool available to these people that 

could enable them to accomplish significant agricultural clearing. 

Archaeological findings from the Woodland Period 

(1000 B.C. to 880 A.D. or 3000 to 1200 B.P.) reflect 

the development of stronger agrarian societies with 

increased trade with other regions. Village sites 

were occupied throughout the year and, toward the 

end of this Period, the cultivation of corn ( 

was introduced from the Southwest. About 

this same time the development of the bow and 

arrow allowed for more efficient hunting. 

By this time the center of the oak populations had 

moved out of the deep South and were concentrated in the central interior region, essentially 

their present positions. The southern yellow pines 

became the dominant species on uplands over 

much of the deep South, probably due to the effects of widespread burning. 

The Mississippian Period (800 to 1540 A.D. or approx. 1200 to 500 B. P.) is considered by many archeologists to overlap with historic (Colonial) time 

in the Southeast. The Southeastern Indians were 

now highly dependent on agriculture with corn as 

their primary crop. Members of the various tribes 

were concentrated in villages located along the 

broad alluvial flood plains where shifting agriculture 

was their primary means of sustenance. 

These continusus shiFTs in land cultivation plus their 

continued use of fire for clearing land and opening 

the forest probably kept a mosaic of various stand 

ages and types in the landscape. It also maintained 

open corridors that favsred plant migration, especially for intolerant species2. Since the implements 

'Personal cammuf;~catian w~th Dr Paul Deicourt and Dr 

Hazel Deicaurt 
Table 2. Late Pleistocene and Holocene events of significance in the 

development of forest types in Southeastern U.S. 

HISTORIC PERIOD: Modern times. 2000 

Settlement times. 

CULTURAL EVENTS calendar 

High Indian mortality. 

America discovered. 1500 

years before CLIMATEfVEGETATIONAL 

~resent STAGES 

MISSISSIPPIAN PERIOD: 

Indian cultures largely 

agrarian, large palisades. 1000 

WOODLAND PERIOD: 

Pottery . 500 

Corn cultivated; bow & arrow. 

AD 

Burial mounds, ---- 0 

BC 

ARCHAIC PERIOD: 1000 

Marked increase in Indian 

population; exchange with 

other regions. 2000 

Beginnings of cultivation with 

fire as the only feasible 

tool for land clearing. 3000 

Archeological evidence that 4000 

Archaic Indians used total 

landscape of So. Appalachians. 

5000 

8000 

PALEOINDIAN PERIOD: Largely 

hunting/gathering tribes; 

fire was an available 9000 

tool. 

First evidence of humans 10000 

in the SE. 

0 Man-made forests widespread, 

Exploitation of forests & soil. 

500 Indian impacts (cultivation & 

fire) mold forest character. 

Northern pines had moved into 

2000 Canada while southern pines 

had moved into Tennessee - 

their present distributions. 

3000 

4000 Sea level rises to modern 

position. 

5000 "Southern pine rise" = marked 

increase in dominance of 

southern pines in SE. 

6000 

7000 Increased summer warmth and 

drought . 

9000 Central hardwood oak-hickory 

forests became established. 

10000 Periglacial climate extended 

as far south as an eastwest line thru Asheville, NC. 

11000 Temperate, deciduous forests 

replace Jack pinelsprucelfir. 

15000 Jack pine, fir and spruce are 

the primary forest types as 

far south as Tennessee. 

18000 ~uI.1 glacial maxima. 
of this time were still Stone Age-type tools, the wide 

range in tree sizes likely enabled them to utilize 

forests to a much greater degree than would otherwise have been possible (e.g., very targe numbers 

of pole-size, straight trees were needed to build the 

miles of pallisades constructed during this period; 

such trees are found only in young, evenaged 

stands). 

The open character of the forest when first viewed 

by EuroAmerican settlers is well documented in 

early descriptions of the landscape as is the 

widespread use of fire by the native Americans (Guffey, 1977). How the popular notion of a closed, high 

forest (variously described as virgin, climax, pristine) covering Eastern North America from the Atlantic to the Great Plains (Day 1953) became so firmly 

entrenched in American thought and popular literature is difficult to explain. Fortunately, popular literature is now recognizing that ". . . the wooded valleys 

and lowlands where Indians lived had been cycled 

and recycled by swidden farming; they weren't the 

'forest primeval' the 'discoverers' eulogizedi' (Billard 

1 989). 

A factor that may partially account for historians 

failure to recognize the open character of the 

"original" landscape is the very high Indian mortality 

throughout Eastern North America during the 16th 

and 17th centuries. European diseases decimated 

l ndian populations after their first white contact. 

DeSoto's large contingent of "explorers" roamed 

through much of the Southeast in 1539-40. Scattered accounts from various parts of Eastern North 

America claim that: 1) at least 80 percent of the Indian population of the Central Mississippi Valley 

died during the 16th and 17th centuries (Phillips 

and others 1951 ; Dobyns 1983 reported by Delcourt 

& Delcourt 1987) and 2) entire villages in the Northeast were wiped out (Cronan, 1975). 

In the various villages these epidemics preceded by 

decades either the arrival of the first settlers or 

those literate enough to provide good historical 

records of the landscape. "Pestilence spreading 

ahead of a wave of settlers is only one example of 

how the influence of a frontier travels in advance of 

that frontier" (Billard 1989). Billard also states that 

"When the Spanish left Florida in 1763, they took 

with them the 83 Christianized suwivors of a 

Timucua population that once had numbered 

15,000." 

By the time historical accounts were being written 

(1 8th century) former lndian old fields and fire-maintained uplands were supporting 50 to 1 50-year-old 

forests that could easily be perceived as pristine 

and virgin. In the Deep South the forests described 

in these early accounts were commonly composed 

of yellow pines, which are pioneer species on disturbed sites. The magnitude of the effort required to 

keep pine on these sites rather than hardwoods, the 

species that comprise the later seral stages that 

replace pines, is well understood by industry today. 

PINE-HARDWOOD STANDS 

The natural and ant hropogenic forces that have 

been altering the Southeastern landscape for the 

past 1,000 to 2,000 years should have encouraged 

the widespread occurrence of pine-hardwood forest 

types. Indian old fields were probably "captured" by 

pure pine stands, as happened following widespread agricultural abandonment earlier in this century. If left undisturbed hardwood encroachment 

would result in a pine-hardwood mixture once the 

invading hardwoods filled the canopy openings that 

occur as pine stands mature and begin to break 

up. Left undisturbed long enough most sites in the 

Southeast will eventually become hardwood stands 

(Kuc hler 1 964). 

A second mechanism was provided where fires 

caused hardwood mortality on frequently burned 

uplands created openings allowing the establishment and development of pines, resulting in a 

pine-hardwood mixture. The quality of hardwoods 

in these stands would be low as fire scars would encourage the decay fungi that cause butt rot. 

However, these "den trees" provide good wildlife 

habitat. Both of these mechanisms through which 

pine-hardwood mixtures were perpetuated 

depended on repeated disturbance. 

In the pre-Columbian landscapes the pinehardwood types were maintained as a mid-sera1 

successional stage that occurred as a shifting 

mosaic. Efforts to "fix" pine-hardwood stands on 

specific sites in perpetuity will be difficult and somewhat "unnatural." 

IN CONCLUSION 

Over much of the Southeast disturbance-initiated 

species have been the dominant forest cover for as 

long as the extant species have been here. Furthermore, for at least the past 10,000 years man has 

been the originator of many of the landscape disturbances that have affected forest composition (according to some anthropologists, "man" is 

responsible for the serotinous-cone character of 

several pine populations). 

The notion that some "natural" forest condition existed in 1492 in the sense of the broad landscape 

being composed of climax forest associations that 

formed independent of a human influence is a 

myth. Further, trying to devise management 
strategies today to try to recapture this "figment of 

our romantic nature and imagination'' is not a viable 

option. Any significant effort in that direction is 

counter productive. 

A serious concern, not only to forest resource 

managers, but the public in general, must be the 

guidelines used to manage the Southeastern 

landscape. It is proper and desirable that there be 

public input into this process, Too often, however, 

the voices heard are from those who have little 

biological training and even less understanding of 

the #'natural" condition that they want to "re-capture. ' Of great concern to the resource managers 

responsible for the wise management of the 

Southeastern forest is the demand that it be 

returned to some "natural" or "original" (pre-Columbian?) condition which they preceive to have 

evolved without disturbance. This demand becomes an anomaly when the evolutionary history of 

the Southeastern forest is understood. 

The hard fact must be established that conditions 

that the average forest user of today perceives as 

"ugly" (i.e., just after a stand-replacement fire) are 

essential to the healthy and "natural" function of 

many forest ecosystems. Such impacts maintain 

the biodiversity that accomodates the wide range of 

species and forest types that characterize the 

Southeastern landscape. The extent to which forest 

managers are allowed to manage the Southeastern 

forests in what they perceive to be a wise manner 

may largely depend on their ability to tell this story 

to a public who increasingly is "calling the plays." 

LITERATURE CITED 

Billard, Jules B. 1989. The World of the American Indian. Washington: National Geographic Society. 

399 pp. 

Braun, E. Lucy. 1950. Deciduous forests of North 

America. Philadelphia: The Blakiston Co. 596 pp. 

Chapman, Jefferson. 1 985. Tellico archeology: 

12,000 Years of Native American History. Knoxville: Tennessee Valley Authority. 136 pp. 

Cooper, John D.; Miller, Richard H.; Patterson, Jacqueline. 1986. A trip through time: principles of 

historical geology. London: Merrill Publishing 

Company. 469 pp. 

Cronon, William. 1983. Changes in the land: Indians, colonists, and the ecology of New 

England. New York: Hill and Wang. 241 pp. 

Davis, Margaret 8. 1983. Annals of the Missouri 

Botanical Gardens. 70:550-563. 

Day, Gordon M. 1953. The Indian as an ecological 

factor in the northeastern forest. Ecology 

34(2) 1329-346. 

Delcourt, Hazel R.; Delcourt, Paul A. 1985. Quaternary palynology and vegetational history of the 

southeastern United States. pp. 1-37. In: Bryant, 

V.M. Jr.; Hoiloway, R.G. eds. Poilen records of 

late-Quaternary North American sediments. 

American Association of Stratigraphic 

Palynologists Foundation. 

Delcourt, Paul A.; Delcourt, Hazel R. 1987. Longterm forest dynamics of the temperate zone. New 

York: Springer-Verlag. 439 pp. 

Guffey, Stanley 2. 1977. A review and analysis of 

the effects of pre-Columbian man on the Eastern 

North American forests. Nashville: Tennessee 

Anthropologist 2:121-137. 

Harlow, William M.; Harrar,Elwood S.; White, Fred 

M. 1979. Textbook of dendrology. New York: McGraw-Hill Book Company. 510 pp. 

Keel, Bennie C. 1976. Cherokee archeology: a 

study of the Appalachian Summit. Knoxville: The 

University of Tennessee Press. 290 pp. 

Kuchler, A. W. 1964. Potential natural vegetation of 

the conterminous United States. American 

Geographic Society, Special Publication #36. 

116 pp. 

Levin, Harold L. 1975. Life through time. Wm C. 

Brown. 21 7 pp. 

Oakes, A. 1939. Economic annuals and human cultures. Cambridge, MA: Botanical Museum, 

Waward University. 
THE DECLINE OF THE MISSOURI OZARK FOREST 

BMEEN 1880 AND 1920 

Robert J. Cunning ham and Carl ~auser' 

.-Missouri's presettlement pine and oak-pine forest once extended over six 

million acres. Today the pine and oak-pine cover types occur on less than 400,000 

acres. Between 1880 and 1920, some of the Nation's largest producing sawmills were 

operating in Missouri's Eastern Ozarks region. A historic review of this period's industrial and social activities toward the Ozark forests illustrates how an area once 

dominated by pine was converted to hardwoods. 

INTRODUCTION 

Industrial and social activities occurring in the Missouri Ozarks between 1880 and 1920, dramatically 

changed the area's oak-pine forest cover. During 

this period, large-scale lumber companies and the 

workers they attracted, thoroughly exploited the virgin forest resources. The effects of this period relate directly to the formation of the present forest 

cover type. 

PRE-INDUSTRIAL PERIOD 

Before 1880, Missouri's pine and oak-pine cover 

types were estimated at 6.6 million acres (Law 

1984; Liming 1946). The range primarily covered 

the southeast Ozark highland on a geographic unit 

known as the Courtois Hills (figure 1). Shortleaf 

pine (Pinu em Mill.) was the dominant 

species and was distributed unevenly across its 

natural range. Associated hardwoods included 

black oak (mrcuvelutina Lam.), white oak (a 

ialkrar L.), scarlet oak (a coccinea Muenchh), and 

post oak (a stellata Wangenh.). Often, it formed 

pure stands; otherwise, it mixed with the 

hardwoods. Early lumber company records indicated that old-growt h pine volumes averaged 4,000 

board feet per acre (Hill 1949). Occasional stands 

containing 25,000 board feet per acre were also 

recorded (Brinkman and Smith 1968; Record 191 0). 

Individual trees with butt cuts nearly 4 feet in 

diameter at the small end of a 16 foot log were common (Hill 1 949). 

Immediately following the Civil War, most of the 

Ozarks was still isolated from settlement and commercial resource exploitation. Its rugged terrain discouraged the only practical means for lumber 

transportation: railroads. Because the demand for 

forest products was concentrated in the more populated eastern United States, Missouri's remote 

forests remained uncut. 

kssistant District Forester, Missouri Department of 

Conservation, West Plains, MO; Silviculture Specilist, 

Missouri Department of Conservation, Jefferson City, 

Figure 1 .--Natural range of shortleaf pine in Missouri. (From Brinkman and Smith 1968) 

By 1880, lumber output from the eastern forests 

had declined (Galloway 1961 ). The westward migration of people through Missouri and on to the treeless Great Plains greatly increased the demand for 

Ozark lumber. When railroad developers showed interest with line construction across southern Missouri, eastern timber speculators were attracted to 

the Ozark pineries. Uncut timberland was cheap 

and often sold for $1 .OO per acre (Hill 1949). Investors pieced together major land holdings that 

formed the resource base for future lumber companies. 

THE LUMBER BOOM 

The Ozark's lumbering boom started in 1887 when 

the railroads began line construction (Hill 1949). By 

then, lumber companies were erecting enormous 

sawmills. Populations increased rapidly as loggers 

and their families were drawn to the new mill towns 

and logging camps. Large towns eventually 
developed at Grandin, Winona. Birch Tree. Leeper, 

Greenville, Doniphan, West Eminence, Midco and 

Bunker, MO (figure 2). Production peaked in 1899 

when Missouri sawmills turned out 724 million 

board feet of lumber (Steer 1948). The boom lasted 

until the early 1920%. 

Most of the large mills were engaged in the 

manufacture of pine lumber. The Missouri Lumber 

and Mining Company at Grandin, MO was the first 

mill to undertake large-scale lumbering in the 

Ozarks (Galloway 1961 ). Orterm referred to as the 

Grandin Mill, its practices and policies were 

developed under the leadership of General 

Manager John B. White and typified the activities of 

other regional sawmills. 

The operations at Grandin were enormous considering current Missouri standards. The milling cmplex comprised two large band miils, one circular 

sawmill, four planing mills, fourteen drying kilns and 

thirty warehouses, with an annual production 

capacity of 75 million board feet. Seventy-five acres 

of old-growth pine were cut daily to feed the mills. 

In 1894, the Grandin Mill was the largest of its kind 

in Missouri and reputed to be the largest operating 

sawmill in the United States (Will 1949). 

Activities away from Grandin centered around the 

togging camps. An eaensive network of companyowned railroads, or tram lines, connected the 

camps to the mill. Most sf the fogs were 

transpafled across these lines Others were floated 

down the Current River during enormous log drives 

Logging practices were best described as tut-andget-atst operations. White had ordered all pine 

trees having a burr: diameter larger than 12 inches, 

or hollow ones containing at least 5 inches of sound 

wood, to be cut and hauled to the mill (Will 1949). 

Hardwoods were hewn into railroad ties and either 

used on the tram lines or sold to other railroads. 

Mid-Continent Iron Company's (BVsidco) operation at 

Midco, MO, is another example of an industry that 

totally exploited the forest. Original1 y, Midco was 

an iron smelting facility. Local timber sources were 

convefled into charcoal lor use in the furnaces. 

Daily wood canscamptian equaled 180 cords. 

During World War I, the United States government 

installed a chemical distillation pknt at Midco. 

Large quantities of wood alcohol, tar, calcium 

acetate and wood oils were recovered from the charFigure 

BIRCH TREE 

2.--Location of Missouri's large forest industry between 1880 and "192, 
coal process (Oakley 1970). During its operation 

period, thousands of acres were completely 

stripped of all forest resources. 

SOCIAL AND ECONOMlC FACTORS 

CONTRIBUTING TO FOREST COVER CHANGE 

The synergic relationship described below between 

the Ozark natives and the lumber companies eventually destroyed the intrinsic values each had 

placed upon the pineries. The activities of both 

groups had drastically curtailed pine regeneration, 

thus allowing a predominance of hardwood 

regrowth. 

People living in the Ozarks prior to the lumber 

boom were subsistence farmers. Most received 

some income by raising livestock on the open 

range. Other forms of agriculture were very limited, 

owing mainly to the rough, stony character of the 

land. The pine forests were well suited to produce 

forage because they were naturally open with an understory of grass. 

With the advent of the big mills came social and 

economic changes to the Ozarks. The industries 

provided employment and a means for woodland 

owners to liquidate timber assets. Reynolds County, MU, for example, was one of the last regions to 

be cut. Its population in 1920 was 10,106, of which 

half were engaged in lumbering (Krusekopf and 

others 191 8). 

Lumber companies had produced some short-term 

economic benefits for the people. However, when 

the timber supplies were exhausted, the companies 

abandoned their operations, leaving behind the unemployed timber workers. These vocationally unadjusted people returned to farming for an economic 

base. Krusekopf and others (1 91 8) best described 

the effects that cutting the forest had on agriculture: 

"After the removal of the pine and the 

larger hardwood trees, a dense growth of 

young oak timber sprang up and the wild 

grasses diminished in abundance, greatly 

reducing the value of the range for pasture. This change did not prove particularly serious at the time, however, since 

more dependence was placed on the income from lumbering, but with the cutting 

of most of the marketable timber and 

return to agriculture the injury became 

more evident." 

Those trying to pasture the cut-over lands had to 

contend with the hardwood regrowth. Intensive 

goat and sheep grazing was one technique used for 

pasture reclamation. Without the continuous grazing, the hardwood sprouts would always return. 

However, fire was the primary means used to sustain the dwindling grass cover. The repeat fires exposed the thin Ozark soils to erosion, robbing the 

hillsides of the nutrients essential for both grass and 

tree growth. 

Several factors contributed to the lack of pine 

regeneration. The lumber companies' severe cutting practices stemmed from the local property-tax 

situation. Much of the lands had been acquired at 

tax sales. Land with timber often sold for the same 

price as cut-over land (Hill 1949). Many of the 

tracts were purchased with uncePtain titles. Because property taxes remained high after cutting, 

companies saved taxes and protected their investments against prior title claims by quickly removing 

any timber and disposing of the land. Without its 

timber, the land was useless to the lumber companies. The lands that could not be sold were abandoned and again auctioned at public tax sales. Any 

interest in reforestation or conservation was discouraged by the prospect of long-term tax investments. 

Timber theft and fire also diminished the possibility 

of natural pine regeneration. Logging had already 

eliminated most of the potential seed trees. Remaining small-diameter pines were often poached from 

company lands. This practice of stealing timber 

was Iscally known as "Grandma-ing" (Galloway 

1961). The term is derived from the statement a 

poacher would make as to the property from which 

a log was acquired: ". . . from Grandma's back 40". 

The annual woods burning by area farmers further 

destroyed pine regenerat ion. Fire killed pine seedlings and caused hardwoods to vigorously 

resprout. Germinating pine seedlings were unable 

to survive under the prolific hardwood canopy. 

Artificial pine reforestation may have been considered by some industry leaders but never practiced. Galloway (1 961), quoted John B. White's 

somewhat erroneous feelings on the matter: 

"I suppose that a vigorous pine forest exhausts from the soil that element most 

adapted for reproducing pine. All through 

the pine forests there are small oak 

bushes which are burned off from year to 

year by forest fires so that they do not get 

a good start. And they are also kept back 

by the shade of the pine forest trees, and 

when these are cut down they sprout and 

thrive in the sunlight and take possession 

of the ground once occupied by the pine. 

However, wherever a pine comes up it appears to grow and it would be easy in my 

opinion to reproduce the pine by 

transplanting and I do not believe that the 

soil is sufficiently exhausted to make it impracticable, but the oak, being more 

vigorous takes the place as opportunity offers." 
After the sawmills were dismantled, some of the lumber companies still owned thousands of cut-over 

acres. By this time, many had switched from the 

manufacture of lumber to selling real estate. Marketing lands worth less than the taxes assessed 

against them was a difficult task. Listings were sent 

across the United States and often included advertisements overrating the land's potential to grow 

fruits and vegetables or sustain livestock. Ironically, 

such schemes were encouraging the same land use 

practices that had compounded the problem of 

pine regrowth. In turn, this discouraged the continued operation of the lumber companies. Large 

blocks of land were sometimes divided into lots of 

2.5 acres or less, and then individually sold. One of 

the more famous subdivisions was created by the 

Munger Securities Company of Hunter, MO. 

Munger lots still retain their original pattern today, 

across many thousands of acres in Carter and 

Reynolds County. The size and abundance of 

these lots made timber management impractical. 

POST LUMBER BOOM RESULTS 

The second-growth forest contains less pine than 

the original stands. In many places, hardwoods 

have completely replaced pine. Today, the pine 

and oak-pine cover types occur on less than 

400,000 acres of Missouri's remaining 12.4 million 

acres of forest land (Essex and Spencer 1976). The 

Pine Valley drainage of Reynolds and Carter Counties is a dramatic example of this change. Named 

for its once-bountiful pine forest, today Pine Valley 

is almost entirely covered with hardwoods. Scarlet 

and black oak are now the dominant species. 

The result of the boom period was a reduction in 

the presettlement forest's unique composition and 

quality stemming from industrial and social interactions. This eastern Ozarks Region today is heavily 

affected by a disease complex known as oak 

decline. In Missouri, this gradual or sudden 

dieback or mortality of oaks is frequently found on 

sites formerly dominated by pines. Red oaks, particularly scarlet, are the most severely affected 

(Gass and Luley 1 988). Since 1 978, management 

of an estimated 180,000 acres of Mark Twain National Forest land has been altered as a result of oak 

decline (Law and Gott 1988). An estimated 30,000 

acres of state forest land and many thousand acres 

of private land are also affected. The large scale 

conversion of the native pine and oak-pine types to 

forests dominated by black and scarlet oak undoubtedly contributed to the current problem. 

To avoid similar conditions in the future, management recommendations must encourage species 

diversity, primarily oak-pine mixtures. This, combined with sustained yield management, should insure a healthy forest throughout the Missouri Ozarks. 

LITERATURE CITED 

Brinkman, Kenneth A.; Smith, Richard C. 1968. 

Managing shortleaf pine in Missouri. Station Bulletin 875. Columbia, MO: University of 

Missouri-Columbia, Agriculture Experiment Station. 35 pp. 

Essex, Barton L.; Spencer, John S. 1976. Timber in 

Missouri. Resource Bulletin NC-30. St. Paul, 

MN. U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station. 

108 pp. 

Galloway, John Albert. 1961. John Barber White: 

lumberman. Ph. D. dissertation. Columbia, MO. 

University of Missouri-Columbia. 267 pp. 

Gass, Ramon D.; Luley, Christopher J. 1988. Missouri Forest Pest Report. Missouri Department of 

Conservation, Forestry Division. Box 180, Jefferson City, MO. 38 pp. 

Hill, Leslie G. 1949. History of the Missouri Lumber 

and Mining Company, 1880-1 909. Ph. D. dissertation. Columbia, Mo. University of 

Missouri-Columbia. 289 pp. 

Krusekopf, H. H.; DeYoung, W.; Watkins, W. I.; 

Deardorff, C. E. 1921. Soil survey of Reynolds 

County, Missouri. Washington, DC. U.S. Department of Agriculture, Bureau of Soils. 30 pp. 

Law, Jay R. 1984. The range of shortleaf pine in 

Missouri. pp. 1-8. In: Artificial reforestation of 

shortleaf pine, a Missouri seminar. 1984, May 9; 

Salem, MO: Mark Twain National Forest and Missouri Department of Conservation. [Available 

from Forest Supervisor's Office, Mark Twain National Forest, Rolla, MO]. 

Law, Jay R.; Gott, Jerry. 1988. Oak decline on the 

Mark Twain- an update. Unpublished paper. 

[Available from the Forest Supervisor's Office, 

Mark Twain National Forest, Rolla, MO]. 

Liming, Franklin G. 1946. The range and distribution of shortleaf pine in Missouri. Technical 

Paper No. 106. Columbia, OH. U.S. Department 

of Agriculture, Forest Service, Central States Experiment Station, 4 pp. 

Oakley, Gene. 1970. Big springs country, the history of Carter County. Van Buren, MO. J-G 

Publications. 144 pp. 

Record, S. J. 191 0. Forest conditions in the Ozark 

Region of Missouri. Bulletin No. 89. Missouri 

Agriculture Experiment Station. 

Steer, Henry 8. 1948. Lumber production in the 

United States. U. S. Department of Agriculture, 

Misc. Publication number 669. Washington D. C. 

233 pp. 
CHARACTERIZATION OF THE HARDWOOD COMPONENT 

IN SOUTHERN PINE COVER TYPES IN THE SOUTHEAST 

Gregory A. Ruark and William A. ~echtold' 

-Forest 'nve~toiy and Analysis ~Fisiii cata indicate that pine cover types comprise 41 percent of the rota8 &orest land ,n Florida Georgra South Carolina North Caroitna and Vrrgrn~a Of 

these 12 7 miilion ail es are piflirrled aqd "1 2 rnm,~iion acres are ~aturally regenerated Many of 

these prne slards cantair coi?sidc:ab!e arrounts of hardwood Understanding the dynamlcs of 

grsbth #r these slancs rbmel~re readires knowledge of pine-hardbood Interact~ons lnformat~on 

#s provided on the hardwood coinponeri ~~th!n natural and planted stands of ioblolly and slash 

pine as well as natural stands b4 osgleaf pond shortieat and ?i~fg;nia pine on both Coastai Plain 

and Piedrncrt sates in :he Ss~iPeas.i 

INTRODUCBLON 

While only 11 percent OF the forested landbase In 

the Southeast (Florida, Georgia, South Carolina 

North Carolina, and Virginia), is classed as oakpine an additional 26 percent is classed as naturally regenerated pine (figure I j These propoflions 

are similar Fcsr both the Coastal Plain and the Piedmont However, total acreage differs, with 11 8 million acres of natural pine an the Coastal Pialn and 

7.8 nlillian acres in the Piedmont Large amounts of 

hardwood basal area are frequently eracoantered nn 

these pine stands. tn some cases the degree acrf 

hardwood cclmpe%it!or^r issuficieni to suggest that 

these stands function more as mixed pinehardwood than as pure pine stands 

This paper uses Forest Inventory and Analysis {FiAS 

data from the most recent (1983 thru 1987) State 

suweys to provide distributional information on 

stand-level variables of age, stocking, site quality 

and hardwood competition within the major planted 

and naturally regenerated pine cover types in the 

Southeast (Bechtolb and Ruark 7 988) Our objective is to identify situations where pine forests are 

moving towards a pine-hardwood composition 

METHODS 

The design of FlA is predicated on the collection of 

a well-distributed, systematic sampie, with proportionate sampling of air major forest types, sites and 

ownerships Approximately 25 COO permanent pihats 

are measured during the course of a survey cycle 

within the five state region adrn~nrstered by the 

Soul heastern Forest Experiment Station Each plot 

represents an average of about 3,400 acres 

Stand-level characterrslics are measured on 

clusters of five sampling points per plot with a basal 

area Factor (BAF) prism sf 37 5 The basal area and 

' Project Leader and %source Arialyst respect,\ e 

Iy dSDA Farest Sewce Sourbeastern Forest Eli 

geiirnent Station 

Coastal Plain Piedmont 

(45,322,367 acres) (26,974,967 acres) 

Natural 

pine Oa k-gins 

Figure 1. Percentage distribution of all timberlands 

in the Southeast, by broad forest type and 

physiographic region. 

number of stems per acre are calculated for each 

major species on the plot (Beers and Miller 1964). 

Stand age and site index are determined from increment cores and height data from dominant and 

codominant trees in the stand (Schumacher and 

Coile 1 960). 

There are three to five suwey units in each of the 

five States. Each suwey unit is confined to one of 

three major physiographic associations (Coastal 

Plain, Piedmont, or Appalachian Mountains). 

In this paper stand composition is evaluated by 

physiographic region averaged over all five States 

and by individual States averaged over 

physiographic regions. Means and standard deviations (weighted by acreage), as well as other statistics required to c harac"iririze t he sband-level 

distribution of age, stocking, site index, and 

hardwood competition for a cover type are 

provided by Bechtold and Ruark (1988). Only mean 

values are discussed in this paper. 
TABLE 1. Average characteristics of naturally regenerated pine a s tarlds by ownership 

Age Site Pine Hardwood 

index stems basal Acres Plots 

area 

Year Feet No. /acre pct 1000 No. 

Coastal Plain 

National Forest 47 67 209 

Other Public 41 64 225 20 1,253 561 

Forest Industry 32 68 286 24 2,172 785 

Farmer 36 73 259 24 2,918 1,030 

Other Private 33 67 264 23 4,958 1,776 

Piedmont 

National Forest 49 74 39 1 26 215 64 

Other Public 40 67 357 21 336 194 

Forest Industry 31 68 459 24 984 292 

Farmer 33 68 383 28 1,917 535 

Other Private 30 67 407 26 4,385 1,209 

a From Tables 23-25, Bechtold and Ruark (1988) 

RESULTS AND DISCUSSION 

Qwnersh~ 

Five ownership categories are recognized: National 

Forest, other public, forest industry, farmer, and 

other private. The average age of natural pine 

stands on National Forest lands exceeds that of 

other ownerships for both Coastal Plain and Piedmont sites (table 1). Site index does not vary greatly 

among ownerships, but site index is higher for 

farmers than others on the Coastal Plain and higher 

for National Forests on the Piedmont. The number 

of natural pine stems per acre is always much 

higher on Piedmont than on Coastal Plain sites. 

However, the average proportion of total stand 

basal area comprised by hardwoods ranges from 

16 to 28 percent and does not differ greatly between the two physiographic regions. The lowest 

proportion of hardwood basal area is on Coastal 

Plain, National Forest sites, while the highest levels 

are manifested on Piedmont farmer ownerships. 

The situation differs for planted pine stands (table 

2). The average age of plantations ranges from 1 2 

to 19 years across all ownerships. The greatest 

average age for plantations, 19 years, is for the 

other public catagory on the Coastal Plain. The 

lowest average site index on the Coastal Plain for 

National Forest land and the highest for farmer holdings. On the Piedmont, avearge site quality is 

similar for all owner groups. The average proportion 

of total stand basal area allocated to hardwoods 

ranges from 9 to 21 percent, with a notably high 

proportion of hardwoods in Piedmont National 

Forest plantations. 

TABLE 2. Average characteristics of planted pine stands by a ownership 

Age Site Pine Hardwood 

index stems basal Acres Plots 

area 

Year Feet No. /acre pct 1000 No. 

Coastal Plain 

National Forest 13 61 562 

Other Public 19 65 358 10 418 207 

Forest Industry 14 69 373 9 6,170 2,243 

Farmer 13 72 331 12 747 269 

0 ther Private 15 68 345 10 1 , 877 698 

Piedmont 

National Forest 13 70 457 21 

0 ther Public 15 73 408 14 50 33 

Forest Industry 12 70 377 11 1,606 485 

Farmer 16 74 288 16 323 90 

0 ther Private 17 73 299 10 767 210 

a From Tables 23-25, Bechtold and Ruark (1988) 
Overall, the ownership data in tables 1 and 2 suggest that there is a substantial hardwood component in naturally regenerated pine stands 

regardless of ownership. The situation exists on 

both the Coastal Plain and Piedmont across a 

range of age classes and sites. 

On Coastal Plain sites the proportion of stand basal 

area relegated to hardwood species increases with 

latitude from south to north; ranging from 12 percent in Florida to 29 percent in Virginia (figure 2). 

These values reflect an average for all pine cover 

types. The difference in hardwood competition with 

latitude on the Coastal Plain is not related to the 

greater acreage of plantations on the south end of 

the gradient (figure 3). The same trend in hardwood 

competition is evident when planted and natural 

stands are viewed separately. There is no apparent 

latitude gradient on Piedmont sites, where the 

proportion of stand basal area occupied by 

hardwoods averages 24 percent in all five States. 

TABLE 3. Average characteristics of naturally regenerated 

stands in the Coastal Plain (CP) and the Piedmont 

(P) of the southeasta 

Site Total --Hardwood-- 

Age Index basal SDI~ Stems Basal Acres 

area area 

Year Feet ~t~/acre - - - pct --- 1000 

......................... POND .................... CP 37 58 69 181111 64 22 1.239 

........................ SLASH -------me----------- 

CP 31 67 7 1 1r 44 18 3,818 P 19 - 43 147 43 9 50 

....................... VIRGINIA ------------------ CP 35 68 121 301 49 27 109 P 32 66 105 265 51 24 1,571 

Calculated from Tables 2-5, Bechtold and Ruark (1988) 

Stand Density Index (Reineke 1933) 

Table 3 gives average age, stocking, site index, and 

hardwood composition for naturally regenerated 

pine stands in the Coastal Plain and Piedmont of 

the Southeast. The number of hardwood stems in 

each covertype ranges from 43 to 66 percent. Since 

many of the hardwoods are small diameter coppice 

sprouts, their basal area better reflects their influence on the pine than does the number of stems. 

Figure 2. Percent of stand basal area in hardwood 

species by state and physiographic region, 

averaged for all pine cover types. (tables 6 and 11 - 

20 from Bechtold and Ruark, 1988). 

Figure 3. Percent of stand basal area in hardwood 

species in natural and planted stands on the Csastat Plain. Averaged and weighted by acreage for 

loblolly and slash pine. (tables 6, 11, 14, 17, and 19 

from Bechtold and Ruark, 1988). 

Loblolly, pond, shortleaf, and Virginia pine stands 

all average in excess of 22 percent hardwood basal 

area on both the Coastal Plain and Piedmont. 

Longleaf stands are the oldest and are often poorly 

stocked with low totai basal area, but have on1 y 1 3 

and 14 percent hardwood basal area on the Coastal 
TABLE 4. Average charact$ristics of natural (N) and planted 

(P) pine stands 

me-- Coastal Plain ---- ------ Piedmont ------ 

Loblolly Slash Loblolly Slash 

N P N P N P N P 

Age (Years) 34 12 31 16 31 13 19 19 

Site Index 75 71 67 67 72 72 - 75 

(Feet) 

Bas L area 103 60 2 '71 53 98 59 43 67 

(Ft /acre) 

Hardwood 

Stems (pct) 66 46 44 26 

Basal (pet) 29 15 18 8 23 12 9 7 

a Calculated from Tables 2-5, Bechtold and Ruark (1988). 

Plain and Piedmont, respectively. These low values 

may reflect the strong tendency of longleaf stands 

to form associations with scrub oaks. Natural slash 

pine stands have 18 percent hardwood basal area 

on Coastal Piain sites, but only 9 percent on the 

Piedmont. Piedmont slash pine stands are notably 

younger and may reflect: recent: changes in management. However, sample size was small for this 

resource. 

Loblolly and slash pine are planted across large 

areas in the Southeast. In excess of 1.2 and 2.4 million acres are planted to loblolly pine on the Coastal 

Piain and Piedmont, respectively. Slash pine plantations are concentrated onto 5.6 million acres of 

coastal sites, with only 337,000 acres planted on 

the Piedmont (Bechtold and Ruark 1988). Coastal 

Plain plantations of both species have roughly half 

the hardwood basal area proportion of corresponding natural stands, reflecting the success of site 

preparation practices and prescribed burning (table 

4). This holds true for Piedmont loblolly pine plantations, but naturally regenerated slash pine stands 

on the Piedmont exhibit a characteristically low 

level of hardwood competition, but the sample size 

is small for this situation. For both loblolly and slash 

pines, the proportion of hardwood basal area was 

always greater on Coastal Plain than on Piedmont 

sites, regardless of stand origin. On Coastal Plain 

sites planted stands averaged as much as 15 percent hardwood basal area and natural stands 

ranged up to 29 percent. 

STAND AGE - YEARS 

Figure 4. Basal area proportion of hardwoods by 

stand age on site index 70-79 loblolly pine sites in 

the Southeast. For planted and naturally 

regenerated Coastal Plain (CP) and Piedmont (P) 

sites. (figures. 18C, 19C, 26C and 27C from Bechtold and Ruark, 1988). 

Hardwood competition varies with stand age (figure 

4). Medium quality (site index 70-79 feet) loblolly 

pine sites in the Southeast were grouped by stand 

origin and physiography. The propoaion of 

hardwoods was lowest between ages 15 and 25 for 

both natural and planted loblolly pine on the Coastal Plain, However, the hardwood component increased as stand age Increased, with hardwoods 

comprising 37 percent of the basal area of natural 

loblolly pine stands by age 65. Piedmont sites 

showed a general decrease in percent hardwood 

basal area from age 5 to 25 regardless of stand 

origin, but no clear trend was present in more mature stands. In general, at any given age the proportion of hardwoods was greater in natural stands; the 

only exception was age 35, at which Coastal Plain 

plantations had more hardwood competition than 

natural Piedmont sites. 
w 

Statewide totals for naturally regenerated loblolly u a3 

pine on Coastal Plain and Piedmont sites were es- to 

timated for medium quality sites (site index 70-79 3.d 

feet) in Noflh Carolina and South Carolina (figure Q: 0 

V) 

5) At all ages, the proportion of hardwoods in 2 30 

Norah Carolina substantially exceeds that on corn- D 20 

parable sites in South Carolina. Whether this dif- 0 

ference is due to management, site, and/or 

0 

3 lo 

environment is not apparent, but it clearly occurs P ix 0 

NATURAL 

throughout the length of the rotation. 

3 

a: 

Q 

zi' PLANTED U) 

4 30 

5i 

i3 SlTE INDEX - FEET 

a: 2 20 Figure 6. Hardwood competition within natural and C 

2%' planted pine stands by site quality in the Southeast 0 

U €x at age 20-29 years. (figures. 18C, 19C, 20C, 21 C, W 

a 10 26C, and 27C from Bechtold and Ruark, 1988) 

STAND AGE - YEARS 

the Coastal Plain and at increasingly northern Figure 5 Csmparlson of hardwood basal area latitudes, where hardwoods already comprise a propoflion in natural loblolly pine stands of North large percentage of the stand basal area, lack of ag- Carolina and South Carolina for site index 70-79 gressive hardwood control measures at hawest will 

lands (figures. 48C and 55C from Bechtold and likely result in many of these stands being reclassed 

Ruark, 1988). as pine-hardwood or pure hardwood cover types 

during the next rotation. Additionally, many naturally regenerated pine stands are already functioning 

The propoflion of hardwood basal area in planted as mixed pine-hardwood stands. This is particularly 

loblolly pine stands declines as site quality im- true of loblolly, shortleaf, and Virginia pine. proves (figure 6). On low quality loblolly pine sites, 

hardwood encroachment is large in both planted The structure of pine stands in the Southeast supand natural stands. The tendency to intensively ports the need for accelerated research into pinemanage better sites may explain this difference. hardwood management. 

However, alternative explanations, such as the 

slower rate of canopy closure on poor sites, may 

result in more hardwood competition. On the best 

Piedmont sites, the hardwood competition in 

natural stands is notably low. For slash pine, the 

hardwood component is generally small across site 

elasses, regardless of stand origin. Except for 

natural slash on the best coastal sites, slash does 

not seem to be severely chatlenged by hardwoods. 

However, our analysis does not examine competition Prom herbaceous plants that could substantially 

comprsmise the water and nutrient resources available to pines. 

CONCLUSIONS 

The mounting pressure to restrict the use of 

prescribed Fire and herbicides, as well as economic 

constraints on management. inputs, will likely 

present more obstacles towards limiting the degree 

of hardwood encroachment in pine cover types. In 

LITERATURE CITED 

Bechtold, W. A.; Ruark, G. A. 1988. Structure of 

Pine Stands in the Southeast. Research Paper 

274. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest 

Experiment Station. 185pp. 

Beers, T. W.; Miller, C. 1. 1964. Point sampling: research results, theory, and application. Res. Bull. 

786. bafayette, IN. Purdue University Agricultural 

Experiment Station. 56pp. 

Reineke, L. H. "133. Perfecting a stand density 

index for even-aged forests. Journal of Agricultural Research. 46:627-638. 

Schumacher, F. X.; Coile, T. S. 1960. Growth and 

yields of natural stands of the southern pines. 

Durham, NC: T. S. Coile Inc. 11 5pp. 
THE GYPSY MOTH IN PITCH PINE-OAK MIXTURES: 

PREDlCTlONS FOR THE SOUTH BASED ON BPERIENCES 

IN THE NORTH 

Michael E. Montgomery, Michael L. McManus,and C. Wayne ~erisford' 

. -Historically, pitch pine-oak stands growing on xeric, poor quality sites in the Northeast 

have experienced frequent and severe episodes of defoliation by the gypsy moth. The dynamics 

of a gypsy moth outbreak in pltch pine-oak stands and in more mesic mixed hardwood stands in 

the Northeast were analyzed. Gypsy moth egg mass densities were sufficient in all stands to 

cause severe defoliation, but such defoliation occurred only in the pitch pine-oak stands, In these 

stands, oaks were severely defoliated, most for 2 successive yeais, but few pines were severely 

defoliated. Mortality of oak species ranged from 7 to 36 pereent while mortality of pitch pine was 

only 13 percent. Oaks generally did not die unless completely defoliated for 2 years. Pitch pine 

always died when completely defoliated and some died that were only 60 percent defoliated, 

Pines are not preferred hosts of the gypsy moth and early instar larvae cannot successfully establish on them; however late instar larvae can feed and complete development on pine. If the hard 

pines of the South are similar to pitch pine in their resistance to defoliation, morlality of pine from 

gypsy moth outbreaks will likely be minor. 

INTRODUCTION 

The gypsy moth ( dlseac) causes substantial defoliation of northern temperate forests in Asia, 

Europe and North America (Montgomery and 

Wallner 1988). It was introduced from Europe into 

North America near Boston, Massachusetts, in 

1869, and was restricted to the New England States 

until 1950 through the actions of regulatory quarantines and barrier zones (McManus and Mclntyre 

1981). In the last 20 years it has more than 

doubled its area of infestation and populations now 

extend south to Virginia and west to Ohio and 

Michigan. 

Preferred hosts include oaks, poplar, some birches 

and larch (Lechowicz and Mauffette 1986; Mosher 

191 5). Pines cannot be utilized by small larvae, but 

late instar larvae are able to survive and develop on 

pines, including loblolly pine (Pin& l.i@h) and 

other species common to the southern United 

States (Barbosa and others 1983). When outbreaks 

of the gypsy moth occur, conifers such as white 

pine ( ) and hemlock 

SIS) may be severely defoliated. Hemlock is particularly vulnerable and catastrophic mortality is the 

usual consequence if it is completely defoliated 

rurner 1963). White pine may be less vulnerable 

than hemlock, in part because it is less likely to be 

totally defoliated since the larvae will eat the new, 

current year needles of white pine only as a last 

resort (Stephens 1 984). 

There are no reports on susceptibility and vulnerability to defoliation by the gypsy moth of stands 

containing hard pines. Stands in the Nofiheast containing pitch pine ( ) usually are classified as susceptible to gypsy math defoliatisn. 

Stands susceptible to defoliation generally occur on 

xeric sites such as rocky ridgetops or wedl-drained 

sand plains (Houston 1981 ). In contrast, resistant 

stands occur on mesic sites with deeper soil. The 

resistant stands have a greater diversity of species, 

with oak often a minor component, whereas the susceptible sites are often 80 to 90 percent oaks. 

Mixed pine-hardwood stands in the South occur on 

a wide variety of sites, but they are more common 

on the drier sites. Loblolly pine and shsrsieaf pine 

(12. echin-) are most frequently associated with 

hardwood species on these sites, particularly oaks 

pp.) and sweetgum ( 

(Knight and McClure 

stands considered to be pure pine frequently have 

a significant hardwood component fTansey 1983). 

In this report, we! will examine the progression and 

consequence of an outbreak of gypsy moth in two 

stands of mixed oak-pitch pine, one toc=a"ied on 

Cape Cod, Massachusetts, and the ather in 

southern New Jersey. These areas were part- of a 

system of research plots established at the onset of 

a region-wide out break of the gypsy moth In 1 972. 

Results from laboratory studies to evaluate the performance of gypsy moth larvae on soma common 

southern hardwoods and loblolly pine also will be 

given. 

'Research Entomologist and Project Leader, 

respectrvely, NoFtheastern Forest Experiment Station, Hamden, CT; and Professor, Department of 

Entomology, University of Georgia, Athens, GA' 

THE INTENSIVE PLOT SYSTEM 

An extensive body af data including gypsy moth 

egg mass densities, sources of gypsy moth mortality, defoliation and su bsequenk tree morlal ity was 
collected from 1972 to 1978 in six forest areas in the 

northeastern United States (figure 1). Each area of 

this '*Intensive Plot System ' (IPS) consisted of five to 

eight sites with each site fairly homogeneous in soil 

type and species composition. Within each site, 

there were five 0.04-ha plots and data were collected on all trees greater than 5 cm dbh. Altogether, data were collected on almost 10,000 

trees for 7 years. M 

Five of the six study areas contained 10 to 13 percent pine (table 1). The pine specie in Areas 2, 3 

and 4 was white pine whereas Areas 1 and 7 contained pitch pine. Areas 1 and 7 contained few 

species other than pine and oak, the latter comprising 82 and 87 percent of the stand stems, respectively. Although Areas 2, 3, 4, and 6 contained 

proportionately less oak, the other species present 

included aspen and white birches and all these 

areas had at least 50 percent of the stems in the 

preferred food class. Thus, each area had the 

potential to support large populations of gypsy 

moth. 

The current threshold for activation of gypsy moth 

suppression programs is 600 egg massesiha (US. 

Department of Agriculture 1989). Densities of egg 

masses in each area, except Area 4, exceeded this 

, threshold in at least one of the years (table 1). 

Severe defoliation, however, occurred only in the 

areas containing pitch pine. Egg mass densities of 

< 400iha resulted in > 55 percent defoliation in 

these two areas whereas, peak densities of 453 to 

2,394 egg masses/ha resulted in defoliation ranging 

from 12 to 40 percent in the other areas. The distinction between the pitch pine-oak stands and the 

other stands lies less in differences of resistance to 

Figure 1 .--Location of the Intensive Plot System population build-up than in resistance to defoliation 

study areas. by high populations of gypsy moth. 

It is not certain why the mesic-site stands in the InAreas 1 and 7 are oak-pitch pine stands located on tensive Plot System were less defoliated than the 

coastal sand-plains, the other areas consist of oak-pitch pine stands but disease could have 

mesic mixed hardwood stands that contain some caused population reduction before the larvae grew 

white pine. to a size that could consume large amounts of 

Table 1. --Summary description of Intensive Plot Sys tem study areas 

Area 

2 Basal area,m /ha 17.9 21.4 24.7 21.1 29.0 13.5 

Total sterns/ha 2006 1238 1242 1159 883 1644 

(pet of total) 

Pines 10.5 11.9 11.7 11.0 0 13.0 

Red oaks 53.3 25.0 23.8 12.3 15.7 27.7 

White oaks 29.1 10.8 40.0 4.1 8.7 59.2 

Other 7.1 52.2 24.6 72.5 75.4 0.0 

Egg masseslha 

Year 1972 316 1300 927 453 516 356 

1973 1497 1345 446 319 2394 6018 

1974 243 562 72 19 145 9 

Defoliation (pct) 

Year 1972 90.4 35.2 16.5 12.1 13.2 55.8 

1973 63.5 15.8 9-1 2-5 39.6 91.5 

1974 9*1 9 2 3.0 0.9 8.4 2.3 
foliage. Epizoot ics of virus disease triggered by 

starvation and other overpopulation phenomena 

are usually responsible for collapse of defoliating 

outbreaks. Disease incidence of older, 4th-6th instar larvae, may be higher on mesic sites than on 

drier sites (Campbell 1963). Oaks growing on xeric 

sites have higher levels of tannins in their foliage 

(Kleiner and others in press). These tannins apparently can decrease the susceptibility of larvae to 

viral disease (Keating and others 1988). Beth pitch 

and loblolly pine foliage contain fairly high concentrations of condensed tannins (Montgomery, unpublished observation). 

Utilization of Species in Oak-Pitch Pine Stands 

The high susceptibility of the coastal-plain pitch 

pine-oak stands (Areas 1 and 7) is most likely a consequence of the high percentage of oak in these 

stands. The presence of a small amount of pitch 

pine, although not a favorable food plant, may be a 

contributing factor because it has structural characteristics that may allow the gypsy moth to better escape natural enemies. 

Pitch, loblolly and other hard pines have very furrowed and rough bark that can provide refuge from 

predators on the forest floor. Bess and others 

(1 947) introduced the importance of structural features, particularly rough, furrowed bark and loose 

bark defects, as a characteristic of forest stands susceptible to the gypsy moth. They found that in 

dense, mesophytic forests gypsy moth larvae that 

went to the forest floor had higher rates of mortality 

than larvae that remained above the floor on the 

tree bole. They observed that forests susceptible to 

gypsy moth defoliation had a higher proportion of 

trees with bark flaps and crevices that encourage 

larvae to remain on the tree bole. 

Egg masses laid on pine may also be exposed to 

less parasitism and virus disease. Rossiter (1 987) 

found that parasitism of gypsy moth eggs by OoenQ!J-&JS kuvan~ was 25 percent lower on pitch pine 

than on oak. Larvae hatching from egg masses 

found on pine had only a 4 to 18 percent incidence 

of nucleopolyhedrosis virus (NPV) compared to 14 

to 57 percent for those found on oak. As pupation 

approached, larvae began to use pine not only as a 

resting site, but also to consume it. At the onset of 

the fourth instar, Rossiter found 3 times the number 

of larvae per tree on oak as on pine, but the numbers of pupae were nearly equal on oak and pine, 

and the number of egg masses was 0.7: 1 oak:pine. 

The work of Rossiter (1 987) in low density populations provides further rationale for gypsy moth to 

utilize pitch pine as a resting and oviposition site. 

The hypothesis that pitch pine is a preferred 

species for oviposition by the gypsy moth was 

tested by examining the distribution of egg masses 

among trees in Areas 1 and 7. To clarify the importance of rough bark, the oaks were separated into 

whites and reds, the former having rougher bark. 

Since tree size can also influence egg mass distribution and the mean dbh of pitch pine was 30 percent 

(Area 1) and 200 percent (Area 7) greater than oak, 

egg mass densities were calculated per stem dbh. 

In 1972, when populations were increasing, more 

eggs per dbh of stem were found on pine than on 

oak in both areas (figure 2). In Area 1 in 1972, all 

species of oak were defoliated and larvae moved to 

pine to complete development; hence, many more 

egg masses were present on pine than on oak in 

the Spring of 1973. White oaks were heavily 

defoliated in Area 7 in 1972 and larvae moved to the 

red oaks to complete development and oviposit the 

eggs that made up the starting population for 1973. 

EGG MASSES per DBH (cm) 

PINES RED OAKS WHITE OAKS 

r 

AREA 1 .O 

.26 

I YEAR 

Figure 2.--Proportionate distribution and density of 

egg masses per cm of stem diameter in two pitch 

pine-oak stands. 

Few egg masses were found in Area 7 in 1974 indicating that the population crashed before larvae 

reached maturity. Overall, populations were more 

stable in Area 1 than in Area 7 where use of pine 

was proportionately less. 

Pitch pine did not experience heavy defoliation in 

either area even though many of the oaks were completely defoliated 2 years in a row (figure 3). In 

Area 1 in 1972, only 25 percent of the pitch pine 

received more than 60 percent defoliation and only 

4 percent was completely defoliated. It was surprising that the pine was not defoliated more, since 

nearly all of the oak was completely stripped of 

foliage. The only species heavily defoliated for 2 

successive years in Area 1 was white oak (Qm 

alba). In Area 7, pitch pine was defoliated even less 

despite the extensive defoliation of oak in 1973. 

Both white oak and chestnut oak (Q. prinus) were 
r igida 

alba 

rubra 

velut ina 

AREA 1 

1972 

AREA 7 

1972 

r igida 

alba 

pta inus cocc ine 

0 

10 35 60 85 100 10 35 60 85 100 

X OEFOLIATION CLASS X OEFOLIATION CLASS 

a. coccinea 

Figure 3.--Defoliation of the most common tree 

species in two pitch pine-oak stands. Class values 

are midpoints except for 100 percent. 

severely defoliated in Area 7 with most of the 

chestnut oak receiving 2 years of 100 percent 

defoliation. Black oak (Q. yelutina) was a minor 

component ( 10 percent of total stems) in the stand, 

and is not depicted in the figure, but it also received 

severe defoliation by the gypsy moth in both years. 

A shortage of food was likely the cause of the 

population collapse in Area 7, but this seems inadequate to explain the collapse in Area 1. Likely, virus 

disease and host specific parasites contributed to 

the population collapse in Area 1, which has had a 

resident gypsy moth population for over 60 years. 

Parasites and disease may have been less 

prevalent in Area 7 since this was the first time it 

was severely defoliated. Natural enemies were 

probably less established and hence only a 

shoftage of food could stop the population outbreak. V 

\b8 b\!03~c0C'r~b $9 c \* 

0 . ' Q* 0. 40 

Mortality of the major species in each area is given Q* 0 Q. 

in figure 4, In Area 1, white oak was the only 

species severely defoliated for 2 successive years AREA 1 AREA 7 

and it had the highest mortality rate. All pines that 

received 85 percent or greater defoliation in 1 year Figure 4.--Tree mortality during a 5-year period 

died. In Area 7, chestnut oak and white oak were (1 973-1 978) in two pitch pine-oak stands defoliated 

the most severely defoliated species; however, mor- by the gypsy moth in 1972 and 1973. 
tality was higher for the red oaks, black oak, and 

scarlet oak (4. coccinea). This was puzzling since 

less than 10 percent of either species were overtopped and the trees were in good condition. 

Review of the original records revealed that these 

oaks received a third successive year of defoliation 

in 1974 by the fall cankerworm (Alsu 

. As in Area 1, few pines died in Area 7 

and some of this mortality may have been due to 

other causes, since a few lightly defoliated pines 

also died. 

The percentage of stems dying was generally 

highest in the overtopped crown class, but for most 

species there were few stems in this category (table 

2). Although 100 percent of the overtopped pine 

died in Area 1, this represented only 4 trees, or 17 

percent of the total mortality of pine in Area 1. Pitch 

pine experienced about the same mortality in all 

three strata in Area 7. Overtopped oaks were also 

more likely to die than overstory oaks, but this represented a significant percentage of the total stems 

sites where tree growth is faster (Houston and Valentine 1977). The small, slow-growing trees on the 

coastal sand-plains probably have low energy 

demands compared to faster-growing trees on better sites. Mortality associated with gypsy moth in 

central Pennsylvania, where growing conditions 

were better, averaged 23 percent for oaks (Gansner 

1 987). 

MBORATORY FEEDING TRIALS 

Gypsy moth larvae were reared in a quarantine 

facility at the University of Georgia at Athens to 

determine the survival and growth of larvae on 

several tree species that are common in southern 

forests. Newly-hatched larvae were placed on the 

foliage shortly after budbreak. The foliage was 

changed every other day to maintain freshness. 

Larvae were reared in two ways: in one case they 

had access to only one species; in the other, they 

had access to a hardwood species plus loblolly 

pine. 

that died. Percent mortality was highest among 

overtopped northern red oak (Q. rubra) and black Survival of larvae varied with tree species. Survival 

oak in Area 1. This represented one-third of the was highest on water oak (8. niara) (29 percent), 

total mortality. In Area 7, mortality was highest followed by sweetgum (26 percent), white oak, (22 

among overtopped oak of all species and over- percent), southern red oak (Q. falcata) (20 percent), 

topped mortality was 26 percent of total mortality. and post oak (Q. $tellat@ (1 7 percent). Only 1 percent of the larvae survived on red maple (Acer 

Considering the severity of defolialtion, the overall rubrum) and no larvae survived beyond the second 

mortality of trees in the pitch pine-oak stands was instar on loblolly pine. The best growth, as 

low, about 16 percent. These forests occurred on measured by pupal weight, was obtained on water 

poor sites for growth. Such sites where tree growth oak (1 .I 5 gm female, 0.45 gm male) followed by 

is slow may experience less mortality than better sweetgum, southern red oak, post oak and white 

Table 2.--Percent mortality by crown class during a 5-year period 

after gypsy moth defoliation; in parentheses is the total number of 

stems, both living and dead, in each crown class. 

CROWN CLASS 

Area Species Uppers tory Intermediate Overtopped 

Pinus rigida 

Quercus alba 

&. rubra 

- Q. velutina 

7 - P, rigida 10.6 (113) 13.6 ( 88) 10.8 ( 37) 

- Q. alba 0.5 (208) 9.8 (215) 27.8 ( 36) Q. prinus - 5.9 (254) 10.3 (312) 28.8 (118) - Q. coccinea* 13.7 (234) 20.8 (120) 27.8 ( 21) 

Q. velutina* - 34.2 ( 76) 35.1 ( 3'7) 57.1 ( 7) 

*Was also defoliated by the fall cankerworm following the 

gypsy moth outbreak. 
oak with 0.85 grn female. O 32 grn male pupal 

weights obtained on the laMer. Since white oak is a 

superior host species in the northern states, these 

data indicate that the southern oak species are as 

suitable as the northern oak species, if not more so 

When the gypsy moth lawae were reared with a 

choice of either loblolly pine or one of the 

hardwood species, they always chose to feed on 

the hardwood, even if it was red maple. The larvae, 

at all stages of development, chose hardwoods over 

pine However, lobloily pine was frequently 

selected as a pupation site 

Large, late instar lawae will consume and survive 

on hard pine foiiage when given no other choice. 

Barbosa and others (1 986) reared gypsy moth first 

on black oak until about half grown and then 

switched them to loblolly pine or Virginia pine (El. . . ), lawae switched to pine aMained female 

pupal weights that were greater than if they had 

remained on black oak. They also observed that 

first instar larvae could not survive on pine. Thus, it 

appears that southern pines are not preferred hosts 

hut may be suitable food for half-grown gypsy moth 

larvae. 

When gypsy moth Iawae do feed on pine, the 

amount of defoliation may be considerably higher 

than expected for a given population size. We 

placed fifth and siHh instar lawae on a tkreeneedled pine with 20-cm long needles similar in appearance to loblolly pine but growing in 

Connecticut. Typically, a larva would exlend out on 

a needle with its hind prolegs attached to the stem, 

sever the needle and backfeed to the needle 

sheath. These lawae, which averaged 0.35 gm dry 

weight, removed about 0.48 gm needles per day, 

but consumed only O 17 gm. This low ratio of only 

35 percent of the severed foliage being consumed 

indicates that relatively low numbers of larvae can 

cause considerable defoliation of pine. By comparison, the gypsy moth is estimated to consume 

86 percent of the oak foliage it removes (Braham 

and WiRer 1978) 

CONCLUSTONS 

Analysis of a historical defoiiatioin episode in oakpitch pine stands in the Nsflbest showed that 

pitch pine was lightly defoliated (< 40 percent) in 

years when oaks were severely defoliated (85-1 00 

percent). The hard-needled pitch pine seems less 

susceptible to defsf iatidan than the soR-needled 

white pine, in Area 2 of the IPS, where defoliation 

of oaks was only 50 percent, white pine was 21 percent defoliated. Herrick and Gansner (1981) obsewed a similar pal"aern of relative defoliation from a 

gypsy moth outbreak in Pennsylvania in 1981 : overail average defoliation was 60 percent for chestnut 

oak, 9 percent for white pine and 1 percent for pitch 

pine. 

Tree mortality varied by species and crown class. 

Nearly all pitch pine that was more than 85 percent 

defoliated died, but overall mortality was only 13 

percent since few pines were defoliated this severely. Because it is a shade-intolerant species, few 

pitch pine stems occurred in the understory. Overtopped pine all died in Area 1, but in the very lightly 

stocked Area 7, mortality was the same in the understory as in the overstory. Mortality of oaks in the 

oak-pitch pine stands varied from 7 to 35 percent 

but differences between species were not consistent 

between the two areas. Generally, overtopped trees 

of all oak species were more likely to die. All oaks 

that died received two or more successive years of 

severe, usually complete, defoliation. 

First instar gypsy moth larvae cannot successfully 

establish on pine foliage, possibly because they are 

limited to feeding on the tough, previous years' 

needles. However, laboratory tests have confirmed 

field observations that half-grown latvae will consume the foliage of hard pines when an alternative 

preferred food is not available. Pine foliage is 

nutritious to late instar larvae and we observed the 

highest number of eggstegg mass and highest densities of egg masses in the stands containing pitch 

pine. 

Based on our experience in the Northeast, we suggest that southern hard pines will be fairly resistant 

to defoliation by the gypsy moth. The dynamics of 

gypsy moth populations in southern oak-pine 

stands and their ultimate impact on the resource 

will vary substantially depending on the ratio of oak 

to pine basal area. A small component of pine in 

these stands may increase the susceptibility of oak 

to severe defoliation. Currently, plots are being established to acquire these data in loblolly pine-oak 

sites in Virginia that are being invaded by the gypsy 

moth. 

For the moment, concern should be focused on 

what impact the gypsy moth will have on 

predominately oak stands in the South. A simulation model of the impact of gypsy moth on North 

Carolina forests (Byrne and others 1987) suggests 

that oak-hickory stands will decrease, while oakpine stands with a high basal area in pine will increase. 
LITERATURE CITED 

Barbosa, P; Waldvogel, M.; Martinat, P. [and 

others], 1 983. Developmental and reproductive 

performance of the gypsy moth, Lvmantria 

(L ) (Lepidoptera: Lymantriidae), on selected 

hosts common to Mid-Atlantic and Southern 

forests. Environmental Entomology 12: 1858-1 862. 

Barbosa, P.; Martinat, P.; Waldvogel, M. 1986. 

Development, fecundity and sunrivai sf the herbivore and the number of plant 

species in its diet. Ecological Entomology 11: 1-6. 

Bess, Henry A,; Spurr, Stephen H.; Littlefield, E.W. 

1947. Forest site conditions and the gypsy moth. 

Hanrard Forest Bulletin 22. 

Braharn, R.R.; Witter, J.A. 1978. Consumption of 

foliage of juvenile and mature red oak trees by 

late instar gypsy moth larvae. Journal sf 

Economic Entomology 91 (3): 425-426. 

Byrne, Stephen V,; Wehrle, Michael M.; Keller, 

Michael A. [and others]. 1987. Impact of gypsy 

moth infestation on forgst succession in the North 

Carolina Piedmont: A simulation study. Ecological Modelling 351633-84. 

Campbell, R .W. 1963. The role of disease and 

desiccation in the population dynamics of the 

gypsy moth, (L.) (Lepidoptera: 

Lymantriidae). Canadian Entomologist 95: 426- 

434. 

Gansner, David A. 1987. Site productivity and tree 

mortality on new frontiers of gypsy math infestation. Res. Note NE-340. Broomall, PA: U.S. 

Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 3 pp. 

Herrick, Owen W.; Gansner, David A. 1987. Gypsy 

moth on a new frontier: Forest tree defoliation 

and mortality. Northern Journal of Applied 

Forestry 4(3): 128-1 33. 

Houston, D.R. 1981 . Forest stand relationships. 

pp. 267-293. In: Doane, C.C.; McManus, M.L., 

eds. The gypsy moth: Research toward integrated pest management. Tech. Bull. 1584. 

Washington, D.C.: U.S. Department of Agriculture, Forest Service. 757 pp. 

Houston, David R.; Valentine, Harry T. 1977. Comparing and predicting forest stand susceptibility 

to gypsy moth. Canadian Journal of Forest 

Research 7(3):447-461. 

Keating, S.T.; Yendoi, W.G.; Schultz, J.C. 1988. 

Relationship between susceptibility of gypsy 

moth larvae (Lepidoptera: Lymanlriidae) to a 

baculovirus and host plant foliage esnstituents, 

Environmental Entomofogy 17(6):952-958. 

Kleiner, M.W.; Montgomery, M. E.; SckuOlz, J.C. 

Variation in leaf quality of two oak species: implications for stand sldscepilibiiiliy to gypsy moth 

deioiialie;rn. Canadian Journal sf Forest 

Research, in press. 

Knight, H.A.; McClure, J. P. 1974. Georgia's timber 

1972. Res. Bull. SE-27. Asheville, NC: U.S. 

Department of Agriculture, Forest Service, 

Southeastern Forest Experiment Station. 48 pp, 

Lechowicz, M.J.; MauMehle, V. 19116. Host prefsrences of the gypsy moth in eastern Narth American 

versus European Farssts. Revue dlEntarnologie 

du Quebec 31 (1 -2):43-51. 

McManus, M.L.; Mclntyre, T, 3 981. introduetiran. 

pp. 1-7 In: Daane, C.C.; MeManus, M.L., eds. 

The gypsy moth: Research toward integrated 

pest management. Tech. Bull, 1584. 

Washington, D.C. U.S. Depaement of Agriculture, Forest Sewice. "75 wpp, 

Montgomery, Michael E.; Waflner, William E. 1988. 

The gypsy matt?: A westward migrant. pp. 353- 

375. In: Berryman, A.A., ed. Dynamics of forest 

insect populations. New Vork: Plenum Publishing Corp. 

Rossiter, MaryCarol. 1987. Use of a secondary 

host by non-outbreak populations of the gypsy 

moth. Ecology 68(4):857-868. 

Stephens, George R. 1984. Heavily defoliated 

white pine has lower mortality than hemlock. 

Frontiers of Plant Science, Fall 1984:4-5, 

Tansey, J.B. 1983. Forest statistics for Georgia, 

1982. Res. Bull. SE-69. Asheville, NC: U.S. 

Department of Agriculture, Forest Service, 

Southeastern Forest Experiment Station. 50 pp. 

Turner, Neely. 1963. EhFect of defoliation by the 

gypsy moth. Bulletin 658. Mew Haven, CT: Connecticut Agricultural Experiment Station. 30 pp. 

United States Depafiment of Agriculture, Forest Service, Northeastern Area, State and Private 

Forestry. 1989. Final environmental impact statement for the Appalachian Integrated Pest 

Management (AIPM) gypsy moth demonstration 

project. Management Bulletin R8-ME3 33. 

Broomali, PA. 117 pp. and 6 appendices. 
GYPSY MOTH IMPACTS IN PINE-HARDWOOD MIXTURES 

Kurt W. Gottschalk and Mark J. ~wer~' 

Abstract. -Gypsy moth has affected pine-hardwood mixtures, especially oak-pine stands, 

since the late 1800's. Several old and new studies on impacts in mixed stands are reviewed. 

When pines are heavily defoliated, considerable growth loss and mortality can occur. Mortality is heaviest in understory white pine trees, Impact information is used to suggest silvicultural management actions to minimize damage in northern mixed stands. Suggestions 

for pre-infestation treatments in southern mixed stands are made, 

INTRODUCTION 

Since its introduction into the United States in 1869, 

the gypsy moth has affected millions of acres of 

forest in the northeastern and middle Atlantic states. 

Many of these forested areas were mixtures of 

hardwoods and conifers, especially mixtures of oak 

and pine. These mixtures have been located 

primarily in southern New England. Information on 

the impacts of gypsy moth on these mixed stands 

has been collected by a number of people over a 

number of years. Our intent is to summarize these 

reports and suggest silvicultural treatments to minimize gypsy moth related impacts in these stands. 

SUSCEPTIBILITY TO DEFOLIATION 

The susceptibility to defoliation is the primary determinant of whether or not gypsy moth will affect a 

stand. Without heavy defoliation levels, there will be 

no significant impacts. Susceptibility will be considered on both the species and stand level. 

Gypsy moth feeding preferences are quite 

pronounced. Some species are favored as food by 

gypsy moth larvae (notably oaks, aspen, birch, and 

sweetgum), while other species are unfavored and 

are rarely fed upon (table 1 .; Mosher 191 5). All 

pines that have been tested have been intermediate; young larvae will not eat their needles, but 

older larvae will readily eat pine foliage. Larvae 

prefer the older needles of both pitch and white 

pine; only rarely do they eat the new needles of 

pitch pine, but new needles of white pine are eaten 

more readily (Hall 1935; Mosher 191 5). Because of 

this feeding pattern, many of the current year needles are not damaged or only lightly fed on unless 

populations are very heavy. White pine growing in 

the understory of mixed or pure stands is much 

more susceptible to defoliation than trees growing 

in the overstory (figure I). In contrast to pine, 

gypsy moth larvae prefer the new foliage of hemlock, so older needles are usually the ones left on 

the tree (Mosher 1915). 

'~roject Leader and Research Forester respectively, 

Nonheastern Forest Experiment Station, Morgantown, 

WV 

Most species tested for gypsy moth suitability have 

been northern species or southern species that 

reach their northern limit in southern New England. 

Loblolly, pitch, Virginia, and shortleaf pine are the 

only southern pines that have been tested and all 

are intermediate (Barbosa and others 1983, 1986; 

Mosher 191 5). In general, soft (white) pines are 

generally preferred over hard (yellow) pines. Sweetgum is the only southern hardwood other than oak 

which has been found to be highly preferred (Martinat and Barbosa 1987; Barbosa and others 1983). 

Many other hardwoods are intermediate, while most 

southern hardwoods, especially understory species, 

have not been tested. 

Stand Level 

Susceptibility on a stand level is determined by 

species composition and site factors (Bess and 

others 1 947; Houston and Valentine 1 977; Herrick 

and Gansner 1986). By far the most important factor is species composition. As the percentage of 

basal area in highly preferred species increases, the 

susceptibility of the stand increases (table 2, figure 

2). Pines growing in mixed stands are more susceptible than pines growing in pure stands because the 

availability of preferred foliage allows the young larvae to survive to the stage where they can then feed 

on pine foliage. In figure 1, overstory and understory white pines were more heavily defoliated when 

growing in oak-pine stands (50 percent oak), than 

in pine-oak stands (2 percent oak), which were in 

turn higher than pure pine stands (90 percent pine) 

(Brown and others 1988). The timing of defoliation 

in mixed stands proceeds as follows: first the 

preferred hosts are defoliated; as they approach 

moderate to heavy defoliation, understory pines are 

beginning to be fed on; as the preferred hosts are 

heavily defoliated, the understory pines are approaching moderate to heavy defoliation and the 

overstory pines have some feeding on them; and 

finally the preferred species and understory pines 

are completely defoliated, while the larvae moderately to heavily defoliate the overstory pines. In severe 

outbreaks, the overstory pines may suffer 1 year of 

moderate to heavy defoliation, while preferred hosts 

like oaks may suffer 1 or 2 years of moderate and 1 

or 2 years of heavy defoliation. 
Table 1.--Break down of woody plant species by gypsy moth food preference 

(susceptibility) classes (adapted from Mosher 1915) 

Class I: Species that are favored food for gypsy moth larvae during all larval 

stages. 

Overs tory: apple, basswood (American linden) , bigtooth and quaking aspen , gray, paper (white), and river birch, boxelder, larch (tamarack), 

American mountain-ash, all oak species, lombardy poplar, sweetgum, 

willow. 

Understory: alder, hawthorn, hazelnut, eastern hophornbeam, serviceberry, all 

sumac species, witch-hazel 

Class 11: Species that are favored food for gypsy moth larvae after the 

earlier larval stages. 

Overstory: chestnut, eastern hemlock, all pine species, all spruce species 

Class 1x1: Nongrefesred species fed upon by later larval stages only when 

preferred foliage is not available. 

Overstory: American beech, black (sweet) and yellow birch, blackgum 

(tupelo), Ohio and yellow buckeye, butternut, sweet and black cherry, 

eastern cottonwood, cucumbertree, American and slippery elm, hackberry, 

all hickory species, Norway, red, silver, and sugar maple, pear, silver 

poplar, sassafras, black walnut. 

Understory: blueberries, pin and choke cherry, American hornbeam, paw paw, 

persimmon, redbud, sourwood, sweetfern. 

Class IV: Unfavored species that are rarely fed upon. 

Overstory: all ash species, baldcypress, northern catalpa, eastern redcedar, 

balsam and fraser fir, American holly, horsechestnut, Kentucky 

coffee-tree, black and honey locust, mulberry, sycamore, tuliptree 

(yellow-poplar). 

Understory: all azalea species, dogwood, elderberry, grape, greenbrier, 

juniper, mountain and striped maple, rhododendron, all rubus species, 

sheep and mountain laurel, spicebush, sarsparilla, all viburnum species 
Table 2.--Average three-year defoliation and stand susceptibility 

to defoliation as related to species composition of the 

stand (adapted from Herrick and Gansner 1986). 

Preferred Three-year Stand 

species average defoliation susceptibility 

pct pct 

low 

moderate 

high 

very high 

Overstory 

1 . Mortality 

Oak-Pine Pin& Pint Oak-Pine Pin&& Pine 

Defoliated Undefoliated 

75-100% 

63 "75% 

Understory C] &SO% 

Oak-Pine Pin& Pins W-Pine PinaOlk Pine 

Defoliated Undefoliated 

Percentage in Oak 

Figure 2.--Defoliation and mortality between 191 2 

and 1921 on Melrose Highlands plots in New 

England, classed by percentage of oak (basal area) 

in the stands (Campbell and Sloan 1977). 

Figure 1 .--Distribution of defoliation of white pine 

trees in the overstory and understory on plots in 

Rhode Island classed as defoliated and undefoliated in 1 981 (Brown and others 1 988). 
IMPACTS ON PINE-HARDWOOD STANDS 

While the gypsy moth has many socio-political impacts in addition to its biological impacts on forest 

stands, we are only considering the impacts on timber production in mixed pine-hardwood stands in 

this paper. Vulnerability is the probability of a tree 

(or stand) suffering impacts, such as mortality of 

trees, growth loss, and changes in species composition, once it has been defoliated. 

Mortalitv 

Numerous papers have been written on the vulnerability to mortality of oaks to gypsy moth 

(Campbell and Sloan 1977; Quimby 1987; Herrick 

and Gansner 1987a). However, we would like to 

bring together the literature on vulnerability of white 

pine and hemlock in New England. Pitch pine, and 

to a smaller exlent Virginia pine, have also been 

studied. Pitch pine is covered in another paper in 

these proceedings (Montgomery and others 1989). 

As shown in figure 2, mortality of oaks is directly related to defoliation, although many other factors influence the process. As with oaks, defoliation 

intensity is a major factor determining vulnerability 

of white pine. Baker (1 941) studied mortality of 

white pines defoliated between 1 91 2 and 1 921 

(figure 3). When only a trace of defoliation occurred on old needles, mortality was less than 5 percent. When all old needles were completely eaten 

and new foliage was defoliated between 0 and 80 

percent, mortality was around 10 percent. Only 

when defoliation of new foliage was greater than 80 

percent, did mortality increase threefold. In 1953, 

similar results were obtained for both white pine 

and hemlock; mortality increased when defoliation 

surpassed 80 percent and hemlock mortality was 

74 percent when completely defoliated (figure 4, 

House 1960). Similar and even more dramatic 

results were obtained for white pine and hemlock 

defoliated in 1981, where 94 percent of the completel y defoliated hemlock trees died (figure 5, 

Stephens 1988). The difference in mortality rates 

between white pine and hemlock are related to the 

defoliation patterns. Since new foliage is consumed 

first for hemlock and it has no capacity for refoliation, complete defoliation causes severe mortality. 

White pine still has many new needles left and they 

have not yet completed elongation when gypsy larvae pupate, so they continue to develop some additional foliage and survive better. 

White Pine mortality 

White Pine growth loss 

Trace 0-20 21-40 41-60 61-80 81-100 

Percent Defoliation 

Figure 3.--Mortality and growth loss of oak and 

white pine between 191 2 and 1921 in New England, 

classed by percent defoliation of study plots. Trace 

defoliation represents old foliage present. A11 other 

categories have all old foliage eaten and various 

degrees of defoliation on new foliage (Baker 1941). 

None 0-40 50 60 70 80 

Percent Defoliation 

Figure 4.--White pine and hemlock mortality after different levels of defoliation in 1953 in New England 

(House 1960). 

Crown class and position also affect the defoliation 

and subsequent mortality of white pine and hemlock. Stephens (1 988) found that understory white 

pine and overstory hemiock tended to be defoliated 
60 70 8 0 9 0 100 

Percent Defoliation 

Figure 5.--Morlality in white pine and hemlock between 1981 and 1984 after defoliation in 1981 in 

Connecticut (Stephens 1988). 

more heavily than overstory white pine and understory hemlock, although hemlock was much more 

uniform that white pine (figure 6). Mortality rates 

showed that while dominant hemlocks were 

defoliated slightly more, they died at half the rate of 

codominant, intermediate, and suppressed trees 

(figure 6). The only mortality in white pine occurred 

in understory trees, dominant and codominant 

trees were defoliated less and did not die because 

they sufiered less than 80 percent defoliation (figure 

ti). Brown and others (1988) showed similar patterns of heavy mortality in understory white pine in 

mixed and pure pine stands that were defoliated, 

while undefaiiated stands had much lower mortality 

rates (figure 7). Quimby (1 987) reported mortality 

rates in Pennslyvania of 39 to 44 percent in 

pulpwssd-sized conifers. Sawtimber-sized trees 

had mortalities of 3, 1 2, 9 to 17, and 0 percent for 

while pine, hemlock, pitch pine, and red pine, 

respectively. In New Jersey, mortality was 31 percent for hemlock and 20 percent for white pine 

(Kegg 1974). Heavy defoliation causes mortality in 

both white pine and hemlock. Overstory hemlock 

dies at a lower rate than understory hemlock. Hemlock dies at a higher rate than white pine. Overstory white pine rarely dies, but understory white 

pine is very vulnerable. 

Since many pines do not die following defoliation, 

the question sf impacts on growth rate arises. 

What does the defoliation of needles do to the 

gt-oWh of pines? Baker (1 941) examined increment 

cores from many oaks and white pines that were 

defoliated to various degrees. He found 20 to 60 

Dominant Codominant Intermediate Suppressed 

Crown Class 

White Pine 

a Hemlock 

Dominant Codominant Intermediate Supgrwsed 

Crown Class 

Figure 6.--Mortality and defoliation in white pine 

and hemlock by crown class after 1981 defoliation 

in Connecticut (Stephens 1988). 

percent losses in radial growth of both white pine 

and oaks (figure 3). The losses in general increased with increasing defoliation intensity and 

were similar between the two groups of trees. 

House (1 960) also looked at diameter growth losses 

of white pine and of hemlock (figure 8). Five-year 

diameter growth losses (compared to previous 5- 

year diameter growth) were not different from undefoliated trees for defoliation intensities up to 80 

percent. For trees defoliated 80 to 100 percent, 

diameter growth losses were double the normat 
Oak-Pkic Pine-Oak Pine Oak-Pine Pin5Oak Pine 

Defoliated Undefoliated 

Figure ?.--Mortality in white pine between 1981 and 

1 983 after defoliation in 1 981 in R hode Island 

(Brown and others 1 988). 

I H wtehepwtfi icsf I [Z) Hemlock growth loss 

An 

None 040 50 60 70 80 90 100 

Percent Defoliation 

Figure 8.--Five-year diameter growth loss in white 

pine and hemlock after different levels of defoliation 

in 1953 in New England. The horizontal bar is a 

reference line representing baseline growth loss 

compared to the previous five years (House 1960). 

loss. These studies suggest that growth losses can 

be as serious as mortality for trees that receive 

heavy defoliation levels. In an interesting study of 

oak-pitch pine mixtures, Campbell and Garlo (1982) 

showed mortality and decline in grovvth of 

defoliated black oaks in the stand and a corresponding increase in growth of pitch pines which 

were only lightly defoliated. Because pitch pine 

was more valuable than black oak, this infestation 

actually increased stand value. Management of 

mixed stands may be affected by differential stand 

growth and developmental patterns resulting from 

differential defoliation patterns. 

When mortality or differential groMh occurs in 

mixed stands, it is possible for the species composition to shift. In oak-white pine stands, greater mortality in the oaks may shift the stand to more 

dominance by white pine initially but with less pine 

in the long run due to loss of understory pines. In 

oak-hemlock stands, a purer oak stand may result 

from the heavy mortality in hemlock. When an oak 

shelterwood stand with white pine regeneration is 

defoliated, the pine can be almost eliminated 

preventing the conversion to pine or mixed oakpine It is also possible for a stand to remain at the 

same relative composition due to mortality in both 

groups (Brown and others 1988). 

SlLVlCULTURAL AND MANAGERIAL 

RECOMMENDATlONS 

Silvicultural treatments to cope with the gypsy moth 

were suggested very early in New England (Fiske 

191 3; Clement and Munro 191 7). Many of the early 

New England prescriptions dealt with mixed oakpine stands and recommended conversion to nonpreferred species. The high value of oak stands 

limits the desirability of conversion. We have 

refined these prescriptions for northern stands and 

also suggested some similar treatments for 

southern stands, although with much less reliabfe information on which to base them. 

There are limited options available to minimize irnpact of gypsy moth by silvicultural means. These 

have been practiced with some success in areas 

where gypsy moth has existed for many years, but 

they may still not be acceptable for some management objectives. The primary means of anecting 

the seriousness of gypsy moth outbreaks are to 

manipulate the species composition away from 

preferred host species and to maintain the vigor of 

the stand. 

Mixed species conditions. In stands with mixed 

pine-oak overstories, the pines are at minimat risk. 

Where stands are white pine and red oak, the pines 

are often dominant individuals which are rarely futly 

defoliated and suffer little or no mortality (Stephens 

1988). In New Jersey forests of black oak and pitch 

pine, Campbell and Garlo (1982) found increased 

growth and vigor of pines when the oaks suFfered 
defoliation and mortality. If pine is the major 

product desired from stands such as these, iittle 

heed need be paid to the gypsy moth. However, if 

oaks are the primary species of interest, the trees 

should not be allowed to stagnate, because trees 

with small crowns and poor vigor are the most vulnerable to gypsy moth outbreaks and the secondary agents which follow. 

Many stands in New England have an overstory of 

oaks with an understory of white pine. These 

stands are often managed as a sheltewood, with 

the overstory oak protecting the pines from the 

white pine weevil until they are over one log tall. 

The stand is then converted to pine by harvesting 

the oak overstory. If a gypsy moth outbreak occurs 

before the oak is removed, the understory pine is at 

great risk. Many of the understory pines will die 

when the lanrae defoliate them after exhausting 

their food supply in the sverstory, The best alternative for management of such a scenario is to harvest the overstory before an outbreak. If the 

overstory is not yet ready for hawest, spraying to 

prevent an outbreak is recommended. 

Where the understory is hemlock instead sf pine, 

the trees are at even greater risk. Hemlock does 

not recover after a Fuil defoiiation. However, it is 

also a less desirable species as timber. The 

primary situation where it is a desired part of the 

stand is where it is needed as cover for game 

species, in which case protection of the stand by 

spraying is the only recommended method for 

retaining hemlock in a mixture with oaks. 

Stands where pines comprise the overstory and 

hardwoods the understory are not as common as 

they are farther south, but this situation does exist 

in some plantations and old-field stands. The understory hardwoods, however, are generally not those 

favored by gypsy moth, such as beech, red maple, 

and viburnum. These stands are generally not at 

risk from gypsy moth outbreaks. If the understory 

develops a large proportion of more favored 

species such as witch hazel, blueberry, or oak, then 

the situation may change. 

Silvicultural options. Reduction of susceptible 

species in a stand is the most reliable way of reducing the threat from gypsy moth (Gottschalk 1982). 

Treatments which might be classified as sanitation 

or presaivage cuttings (Smith 1986) are typical 

methods of achieving this reduction. In these treatments the proportion of the stand in susceptible or 

vulnerable trees is reduced sufficiently to decrease 

the likelihood of an efiensive outbreak. The extreme form of this method is stand conversion, 

which leaves only trees which will not support a 

gypsy moth population. 

If the situation is such that a susceptible species is 

still the most desired tree, such as in a stand 

dominated by red oak, the best available method to 

reduce hazard is to maintain a vigorous stand. The 

most vulnerable trees, even among favored host 

species, are those with small crowns or many dead 

branches within the crown (Herrick and Gansner 

1987b). if a stand is maintained in an uncrowded, 

vigorously growing condition, there is less 

likelihood that a defoliation will cause mortality (Gottsc ha1 k 1 982). 

Little information and few options are available to 

minimize impact of gypsy moth by silvicultural 

means in southern stands. Some success from 

areas where gypsy moth has existed for many 

years can be transferred south, but they still may 

not be acceptable for some management objectives 

and some conditions. The principal techniques for 

reducing the impacts of gypsy moth outbreaks farther south are to manipulate the, species campssition away from preferred host species and to 

maintain the vigor of the stand. 

Mixed Species Conditions. Southern mixed stands 

have a much broader and more varied composition 

than northern stands. All across the South, the 

major mixed stands are oak-pine stands that contain 50 percent or more oak, and 25 to 50 percent 

southern pines with hickories and blackgum as 

common associates. In these stands, pine will 

probably not suffer extensively compared to the 

oaks. If pine is desired, then gypsy moth will not 

need to be managed. However, if oaks are important for timber or wildlife habitat, then they should 

be kept in vigorous condition with large, healthy 

crowns by thinning. Healthy trees are the least likely to die from gypsy moth defoliation and subsequent secondary organism attack. 

In the Piedmont and Coastal Plain, southern pine 

stands can have up to 40 to 50 percent hardwoods 

growing with the pines. The variety of species differs widely with site and stand conditions. When 

enough of the hardwoods are preferred species 

such as oaks or sweetgum, it is likely that gypsy 

moth populations will rise high enough to affect the 

pine However, since the pine is usually the desired 

product, loss of the hardwoods may be of little cansequence and even benefit the growth and value of 
the stand. One fear expressed by some southern 

entomofogists, is that enough damage will be done 

to the southern pines, especially loblolly, to stress 

the trees sufficiently to cause a southern pine beetle 

outbreak to start in the stand.2 

Stands where pines dominate the overstory and 

hardwoods the understory occur across millions of 

acres in the South. Many of these southern understory species have not been tested for their gypsy 

moth feeding suitability. if sufficient numbers of 

preferred species are present in the understory, it 

may be possible that enough gypsy moth larvae will 

survive to a stage where they can move to the pine 

foliage. Some tests have shown that this situation 

may enhance the survival of the gypsy moth (Rossiter 1987; Barbosa and others 1986). Again, just 

enough stress could be placed on these pine trees 

to trigger other pest problems. 

The best silvicultural treatment in mixed oak-pine 

stands is to reduce the proportion of susceptible 

species in the stand to a level that places lass risk 

on the stand as a whole; less than 50 percent of the 

basal area is good, less than 30 percent Is better, 

and less than 15 to 20 percent is best, but hard to 

achieve in less than two thinnings, The extreme 

form of this treatment results in stand conversion to 

nsn-preferred species, or a gypsy moth-proof stand. 

Where is it neither practical nor desirable to convert 

or reduce preferred hosts sufficiently, then thinnings should be used to increase the vigor of the 

remaining trees. Development of large, healthy 

crowns will increase the probability of a tree surviving defoliation. It will also have the often desirable 

effect of increasing mast production of the oaks. 

Many stands may need to be protected with a 

chemical or biological insecticide. Especially vulnerable are seed tree or shelterwood stands that 

are in the process of regenerating the stand. Loss 

of these trees can destroy the entire treatment. 

Depending upon the situation with host suitability of 

understory trees, it may be desirable to remove 

preferred species from the understories of pine 

stands to protect them from stress caused by the 

gypsy moth. This treatment will have the benefit of 

preventing subsequent pest pro biems that may 

arise from stress on the pines at a much lower total 

cost than treating the secondary pests. 

'~ersonai commun~cation, C Wayne Berisford, 

Department of Entomology, University sf Georgia, 

Athens GA. 

RESEARCH NEEDS 

Many unanswered questions exist for mixed pinehardwood stands, especially for southern forest 

types. A few of the more important questions are: 

1. What are the host feeding preferences of many 

southern species? 

2. What are the species compositions and stand factors that affect stand susceptibility in pinehardwood mixtures in the South? 

3. What are the impacts (mortality and groWh loss) 

in pine-hardwood types in the South? 

4. Can appropriate silvicultural treatments minimize 

gypsy moth impacts in pine-hardwood mixtures in 

both the North and South? 

LITERATURE CITED 

Baker, W.L. 1941. Effect of gypsy moth defoliation 

on ceflaln forest trees, Journal of Forestry 

39:1017-1022. 

Barbosa, P.; Martinat, P.; Waldvsgel, M. 1986. 

Development, fecundity and suwival of the herbivore and the number of plant 

species in its diet. Ecologicai Ewtsmology 1 1 :I -6. 

Barbosa, P.; WaldvogeC, M.; Martinat, P. [and 

others]. 1983. Developmsntal and reproductive 

performance of the gypsy moth, 

(L.) (Lepidoptera: Lymantriidae), on selected 

hosts common to mid-Atlantic and southern 

forests. Environmental Entomology 12(6): 1858- 

1 862. 

Bess, Henry A.; Spurr, Stephen H.; Littlefield, E.W. 

1947. Forest site conditions and the gypsy moth. 

Harvard Forest Bulletin 22. 56 pp. 

Brown, James H.; Cruickshank, Valerie €3.; Gould, 

Walter P. [and others]. 1988. Impact of gypsy 

moth defoliation in stands containing white pine. 

Northern Journal of Applied Forestry 5:108-111. 

Campbell, Robert W.; Garlo, Albert S. 1982. Gypsy 

moth in New Jersey pine-oak. Journal of Forestry 

80: 89-90. 

Campbell, Robert W.; Sloan, Ronald J. 1977. Forest 

stand responses to defoliation by the gypsy 

moth. Forest Science Monograph 19. 34 pp. 

Clement, G.E.; Munro, Willis, 191 7. Control of the 

gipsy moth by forest management. Agric. Bull. 

484. Washington, DC: U.S. Department of Agriculture, Bureau of Entomology. 54 pp. 

Fiske, W.F. 1913. The gipsy moth as a forest insect, 

with suggestions as to its control. Agric. Circ. 

164. Washington, DC: U.S. Department of Agriculture, Bureau of Entomology. 20 pp. 
Gottschalk, Kurt W. 1982. Silvicultural alternatives 

for coping with the gypsy moth. pp. 137-1 56. In: 

Finley, J.C.; Cochran, S.R.; Baughman, M. H., 

eds. Proceedings, Coping with the gypsy moth; 

1982 February 17-1 8; University Park, PA: Pennsylvania State University. 166 pp. 

Hall, Ralph C. 1935. Cape Cod pitch pine: Its resistance to gipsy moth defoliation and its 

advantages as a forest tree. Journal of Forestry 

331169-1 72. 

Herrick, Owen W.; Gansner, David A. 1986. Rating 

forest stands for gypsy moth defoliation. Res. 

Pap. NE-583. BroomaI1,PA: U.S. Department of 

Agriculture, Forest Service, Northeastern Forest 

Experiment Station. 4 pp. 

Herrick, Owen W.; Gansner, David A. 1987a. Gypsy 

moth on a new frontier: forest tree defoliation and 

mortality. Northern Journal of Applied Forestry 

4:128-133. 

Herrick, Owen W.; Gansner, David A. 1987b. Mortality risks for forest trees threatened with gypsy 

moth infestation. Res. Note NE-338. Broomall, 

PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 4 

PP. 

House, W.P. 1960. Gypsy moth-white pine damage 

study. Final Report: U.S. Department of Agriculture, Plant Pest Control Division. Reprinted in 

Turner, N., ed. 1963. Effect of defoliation by the 

gypsy moth. Bulletin 658. New Haven, CT: The 

Connecticut Agricultural Experiment Station. 30 

PP. 

Houston, David R.; Valentine, Harry T. 1977. Comparing and predicting forest stand susceptibility 

to gypsy moth. Canadian Journal of Forest 

Research 7:447-461. 

Kegg, John David. 1974. Quantitative classification 

of forest stands as related to their vulnerability to 

loss following initial outbreak of the gypsy moth, 

Porthetria diu (L.), with equations for forecasting basal area losses. New Brunswick, NJ: 

Rutgers University. 36 pp. Thesis. 

Martinat, Peter J.; Barbosa, Pedro. 1987. Relationship between host-plant acceptability and 

suitability in newly eclosed first-instar gypsy 

moths, (L.) (Lepidoptera: 

Lymantriidae). Annals of the Entomological 

Society of America 80: 141 -1 47. 

Montgomery, Michael E.; McManus, Michael L.; 

Berisford, C. Wayne. 1989. The gypsy moth in 

pine-oak miflure$: predictions for the south 

based on experiences in the north. [This Proceedings]. 

Mosher, F.H. 1915. Food plants of the gipsy moth 

in America. Agric. Bull. 250. Washington, DC: 

U.S. Department of Agriculture, Bureau of Entomology. 39 pp. 

Quimby, John W. 1987. Impact of gypsy moth 

defoliation on forest stands. pp. 21 -29. In: 

Fosbroke, Sandra; Hicks, Ray R. Jr., eds. 

Proceedings of coping with the gypsy moth in the 

new frontier: a workshop for forest managers; 

1987 August 4-6; Morgantown, WV: West Virginia 

University Books. 153 pp. 

Rossiter, MaryCarol. 1987. Use of a secondary host 

by non-outbreak populations of the gypsy moth. 

Ecology 68:857-868. 

Stephens, George R. 1988. Mortality, dieback, and 

growth of defoliated hemlock and white pine. Northern Journal of Applied Forestry 5:93-96. 

Smith, David M. 1986. The Practice of Silviculture. 

8th ed. New York: Wiley & Sons. 527 pp. 
SITE QUALIN: THE ECOLOGICAL BASIS FOR 

PINE-HARDWOOD MANAGEMENT DECISIONS 

Robert Zahner and Glendon W. ~rnalle~' 

-S~te productivity and tree species compos~tion are the essenfrat ingredrents rn 

forest management plannlng for multtple uses Prne-hardwood mlxtures one< forest 

managers many cholcec and beaef~ts for all resource ou?puts timber quality and quantity, 

w~ldl~fe hab~tat, water quallty and quantlty and recreation oppslrtutl~tres S~te qualrty erther 

enhances or l~mrts management choices of these outputs Although desirabte mcall~pie 

forest benef~ts can be achievea w~th p~ne-hardwood mrxtures on nearly all srtes spec~fic 

resource outputs depend almost entrrely on the edaphrc character~st~cs of a grven site In 

l~ght of an ant~cipated warmlng cl~mate for the southeastern Un~ted States over the next 

several decades a divers~ty of tree species on every sire w~li provide maximum protectton 

from erratlc weather and attendant pests 

INTRODUCTION 

It is a fundamental principle of forest ecology that 

site quality and climate together determine species 

composition and the productivity of those species 

(Spurr and Barnes 1980). In the South, much emphasis has been placed on the concept of speciessite suitability, that is, adapting or matching a single 

pine species or a pure hardwood type to a given 

site, based almost solely on the economic productivity of certain species-site combinations (Barrett 

1982). In managing mixtures of pines and 

hardwoods, this concept of species-site suitability 

goes one step further - to the desired resource outputs As the magnitude of genetic input increases, 

so does the opportunity for more diverse resource 

output, but only as enhanced or limited by site 

quality and climate (figure 1). Resource outputs 

begin with the quality of sites existing under a given 

climate. Since the range of resource outputs increases in direct proportion to the degree of forest 

diversity, pine-hardwood mixtures seem to offer 

forest managers more options than either pure pine 

or pure hardwood forest types. 

ENVIRONMENTAL INPUT 

(Site Quality and Climate) 

Another consideration that is cerhain to affect forest 

management decisions is the prospect of global 

warming. In the South, we can expect drier summers in the Piedmont and possibly weaer growing 

seasons along the coast and in the mountains 

(Manabe and Wetherald 1986, Solin and Boos 

1986). Csnsequentl y forest site quality will gradually 

change and. no doubt, site wilf exercise mere control over forest resource outputs in the near future. 

PINE-HARDWOOD SITES IN THE SOUTH 

There are several recent overviews of forest habitats 

and their classificatisn by physiographic provinces, 

landtypes, and cl irnates t hrsughout the South 

(Hodgkins and others 1996; Evans and others 1983; 

Pahner 1984; Pehl and Brim 1985; Smalley 1986~1, 

1986b; Myers and others 1986). We will not 

reiterate the detaits of these publications, nor discuss the edapkic and climatic factors contributing 

to variations in forest site quality. Many pine and 

hardwood species occur nat urafl y in all regions of 

the South, and, evidently: in pre-seulernent times alRESOURCE OUTPUTS 

Timber Quality and Quantity 

Wildlife Habitat 

FOREST PRODUCTION Watershed Values 

(Martagemen4 Pracl~ces) Recreation Opportunities 

Scientific Values 

(Tree Species Diversity) 

'Professor, Department of Forestry. Clemson 

University, Clemson, SC; and Princ~pal Soil Scientist (Retired), Southern Forest Experiment Station, 

Sewanee, TN 

\ Wilderness Habitat 

Figure 1. Diagram illustrating haw site quality and 

climate constitute the ecological basis Far forest 

resource outputs. 
most always in mixed stands (Braun 1950). With 

few exceptions, e.g. first bottom river floodplains 

and high elevation mountain habitats, there are 

probably no sites in the South that have not supported pine and hardwood mixtures at some time in 

the past. Therefore, the potential exists for the 

management of pine-hardwood mixtures in almost 

all forest habitats of the South. 

For the remainder of this paper, we assume that the 

forest landowner or manager prefers to maintain 

stands of mixed pines and hardwoods. The 

management objectives may vary from timber and 

wildlife considerations to aesthetics. Today there is 

much emphasis on maintaining species diversity, 

both plants and animals, as an ecologically sound 

and ethically "right" approach to land stewardship 

(Wilson 1988). Thus the "value" to society of pinehardwood mixtures lies in both economic and noncommodity resources. Also emerging in the 

biological sciences is an urgency to preserve (and 

to restore damaged) ecosystems of all types (Millar 

and Ford 1988; Cairns 1988). The diversity of 

habitats in the South, created by the diversity of 

landforms, soils, climate, and plant and animal 

species, assures that forest management can 

achieve all of the above societal values* In our 

opinion, managing for pine-hardwood mixtures can 

augment these values on nearly all sites. 

Forest habitats in the South, of course, have been 

subjected to over 200 years of major disturbances 

by European man, and even the least disturbed 

sites or those with the longest periods of recovery 

are not truly pre-Columbian ecosystems. Abandoned agricultural lands are the most extensive altered ecosystems, but the nature of forest 

succession assures that both pines and hardwoods 

are present in the site recovery process. Extremely 

damaged sites, such as those resulting from strip 

mining or gully erosion, require restoration methods 

that utilize diverse mixtures of tree species, including both pines and hardwoods on the same site, in 

order to achieve desired rehabilitation objectives. 

Less-altered habitats, in particular those converted 

from hardwoods to planted southern pines, almost 

always continue to support a mixture of residual 

hardwoods that play an important role in soil structure and fertility. Mixed hardwood forest vegetation 

increases the incorporation of organic matter, improves soil nutrient status through more diverse cycling of minerals, improves nitrogen fixation, 

increases infiltration of water, improves soil aeration 

and water retention, and in general results in 

gradual, long-term improvement of site quality for 

both pines and hardwoods (Zahner 1982). 

The array of historical land uses in the South 

amplifies opportunities for mixed pine-hardwood 

management through both the environmental and 

genetic inputs illustrated in figure 1. Site quality 

and species composition have been diversified by 

the many patterns of past land use and habitat disturbance and recovery, thus contributing to a wide 

array of possible management outputs. 

In the following section we discuss some of these 

management outputs for various pine-hardwood 

habitats throughout the South. 

EXAMPLES OF SITE-REGULATED 

MANAGEMENT DECISIONS 

Piedmont Uplands 

So-called "pine sites" in the Piedmont region were 

originally classed as oak-pine by early ecologists 

(Braun 1950). Both oaks and pines are naturally 

well-adapted to Piedmont uplands, and both types 

are drought tolerant. In spite of determined and aggressive attempts to control them, the typical mixture of hardwoods that occur on "pine sites" are 

here to stay and offer the landowner both economic 

and non-commodity resources. Quality hardwood 

sawlogs, of course, cannot practically be grown on 

many upland sites, but hardwood pulpwood is now 

as valuable a resource as pine. 

Biomass produced during the early years by the 

hardwood component in a stand of equal mixture 

should exceed that of the pine because of the rapid 

growth of young hardwood sprouts and their high 

wood specific gravity (Zahner and Harris 1984). 

Typical Piedmont uplands with a basal area mixture 

of 60 percent pine, 20 percent oak, and 20 percent 

other hardwoods might reasonably be expected to 

support a volume of 24 cords of pine and 16 cords 

of hardwood per acre at age 30 (Zahner 1982). A 

thinning might remove 20 percent of the pine basal 

area and 40 percent of the hardwood, yielding perhaps 5 cords of pine and 6 cords of hardwood per 

acre. This type of management would leave a good 

mixture of pine crop trees for future sawlogs and 

mast-producing oaks and other hardwoods to enhance wildlife habitat. 

Blue Ridge Mountains 

The southern Blue Ridge Mountains were assigned 

to the oak-chestnut forest region (Braun 1950). 

Here the native mixture of eastern white pine and 

upland oaks and other hardwoods has undergone 

severe alteration by European man. The potential 

remains, however, to manage mixed pinehardwood stands on many mountain sites for 

diverse multiple use outputs. Planting of eastern 

white pine at wide spacings on clearcut hardwood 

south slopes results in a future potential for pine 

sawtimber mixed with mast-producing oaks and 
other hardwoods for enhancement of wildlife 

habitat. South-facing mountain slopes tend to have 

shallower soils than north-facing slopes, and, invariably support plentiful oak regeneration, but 

have little potential for producing hardwood sawtimber under a warming climate. 

Several native species of pines whose seed source 

has been eliminated by past hawesting and other 

land-use practices, including eastern white pine, 

shortleaf pine, Table Mountain pine, and pitch pine, 

when reintroduced have excellent potential for small 

sawtimber in mixture with naturally occurring 

hardwoods. On north-facing lower slopes, and in 

coves, where yellow-poplar makes its best development in the mountains, eastern white pine also has 

its greatest potential for quality growth, with both 

species reaching a site index of 100 (base age 50). 

Eastern white pine and yellow-poplar were once 

natural mixtures on such sites, probably reprod ucing and suwiving together in even-aged stands following natural disturbances through thousands of 

years (Braun 1950). 

Southern Ridge and Valley 

The Southern Ridge and Valley is split between the 

oak-chestnut and the oak-pine forest regions 

(Braun 1950). Because of drastic land-use changes 

wrought by European settlers during the 19th and 

20th centuries, forests are largely confined to ridges 

and steep sideslopes, where soils are generally shallow over shale and sandstone and low in fertility. 

These uplands are a mosaic of oak-dominated communities, in mixture with Virginia and shortleaf 

pines (Martin 1971 ), with site indices for both oaks 

and pines varying locally from 60 to 80. Such forest 

sites obviously do not offer potential for large sawtimber, but wildlife habitat, recreation, and watershed values are high. 

Most woodland ownerships are small and highly 

fragmented, enhancing these non-timber management options along with a high firewood demand. 

A few better sites offer potential for pine-hardwood 

timber production, where either natural or planted 

loblolly pine occurs in mixture with yellow-poplar on 

stream terraces, small bottoms, and talus slopes 

where soils are deeper and site index can reach 

100 for these two species. 

Cumberland Plateau and Mountains 

Although this province has been classed in the 

mixed mesophytic forest region (Braun ?950), twothirds of the Plateau surface supports natural mixtures of pines and hardwoods; the mesophytic 

forest types are restricted to coves, gorges, and 

cool slopes (Smalley 1986a). Virginia pine, shortleaf 

pine, and pitch pine are common associates with 

oaks on dry ridges with shallow to moderately deep 

soils, where site index is generally below 75 for 

these pines and below 65 for oaks. Pure stands of 

native pine are generally limited to abandoned 

cropland and other disturbed sites, and support 

moderate to dense hardwood understories, providing potential for the development of true mixed pinehardwood stands. 

High quality sites are on cool slopes and in coves in 

the Mountains, and on cool escarpment slopes and 

in gorges and stream bottoms on the Plateau. 

Here, where site index approaches 100 for yellowpoplar and eastern white pine, and 70 to 80 for 

oaks and yellow pines, there is opportunity for 

quality sawtimber outputs of both pines and 

hardwoods. 

Re-esta blishing native pines or introducing loblolly 

pine in mixture with hardwood residuals, offers a 

low-cost option for rehabilitating many low-quality 

stands (Sims and others 1981). Although loblolly 

pine has been extensively planted in aggressive 

management programs, this species may be limited 

to short rotation crops because of damage from periodic glaze storms. Another option may be planting eastern white pine in cut-over mixed stands on 

the undulating Plateau surface (Personal communication, W. C. Davis, University of the South). 

Several recreation-oriented management outputs, including game animal habitat improvement and 

scenic values, are important in this region, and are 

enhanced by establishment of mixed pinehardwood stands on a wide variety of sites. 

Highland Rim-Pennyroyd 

Although Braun (1 950) described the forests of this 

province as a mosaic of oak-dominated communities reflecting the widespread influence of man, 

shortleaf and Virginia pines occur throughout the 

Rim, lending the forests naturally to mixed pinehardwood management (Smalley 1986a). As with 

most of the other provinces in the Appalachian 

region, woodlands on the Eastern Rim consist for 

the most part of small fragmented tracts, but become more extensive on the Western Rim. 

Loblolly pine occurs naturally on the Alabama portion of the Rim, and is also an option for planting 

farther north into middle Tennessee. As on the Cumberland Plateau, however, loblolly pine is susceptible to damage from winter glaze storms and may 

not be suitable for sawlog rotations along with oaks 

and other hardwoods. All landforms on the Rim 

support mixtures of pines and hardwoods, with site 

indices varying from 60 to 70 for upland oaks and 

native pines on ridges and north cherty slopes, and 

from 80 to 90 for yellow-poplar and planted loblolly 

pine on better sites. Planting yellow pines in 

cutover upland hardwoods is also a low-cost option 

for rehabilitating many poor sites and low quality 
stands on the Rim-Pennyroyal (Sirns and others 

1981 ). Pine-hardwood management outputs on the 

Rim include a full array of options, with limber 

production, wildlife habitat, and recreation equatty 

feasible. 

This province is the most extensive in the 

Southeast, occupying all of the upper Coastal Plain 

south of the Piedmont Fat1 Line from Wrginia into 

Alabama, thence northwest across northern Mississippi into West Tennessee, thence west beyond the 

Mississippi alluvial floodplain across Arkansas and 

Louisiana into East Texas (Zahner 1 984; Smalley in 

press). Except for that portion occurring in Tennessee, the Hilly Coastal Plain encompasses the 

heart of native loblolly pine, and thus this species is 

the favored pine component in pine-hardwood 

management. Land use here is still highly agricultural, although the southern pulpwood industry has 

established extensive tracts of lobloll y pine plantations throughout. 

Today the focus of mixed pine-hardwood management is with non-industrial woodlands where wildlife 

and recreation outputs are more desirable than 

pine timber outputs. With the present hardwood 

pulpwood market expanding rapidly, ail types of 

ownership may move strongly toward mixed pinehardwood management in the near Future. Site 

quality throughout the uplands of the Haly Coastal 

Plain is generally good to excellent, where deep 

soils are well developed in the unconsolidated 

sands and clays. Managed stands are productive 

on every major land type, with site index over 85 for 

loblolly pine and comparable for such hardwoods 

as southern red oak, white oak, sweetgum, and yeilow-poplar. Because mixed pine-hardwood stands 

should be more productive over a larger land area, 

as well as on a larger array of sites throughout this 

province than elsewhere, timber outputs will probably take precedence over other woodland management objectives. 

In West Tennessee, the soils of this province are 

fragile, formed in loess overlying the unconsolidated sands and clays that are the typical soil 

parent materials of the rest of the province, Here, 

just north of the natural range of loblofly pine, native 

shortleaf and Virginia pines predominate in natural 

mixed pine-hardwood forests. Because loblolty pine 

has been extensively planted on former croplands, 

particularly to aid control of severe erosion of these 

fragile soils, stands of mixed pine-hardwoods are 

sewing the important primary objective of watershed protection along with various wildlife and 

recreation outputs. 

This province lies east of :he Mississippi River 

floodplains, where high-quality saLvtimber stands of 

both pines and hardwoods occur in a mosiac of 

species types conforming to the broken topography 

and land forms (Zahner 1984). Soils are fertile with 

a moist water regime, developed in loess parent 

materials in the high rainfalt climate of the central 

Gulf Coastal Plain. Lobloliy pine, cherry bark oak, 

yellow-poplar, and sweetgum occur in both pure 

stands and natural mixtures, with site index for all 

species general1 y over 100. Here forest management opporlunities include a wide variety of timber 

and wildlife outputs blended with stand-by-stand 

species composition (Mann and others 1979). The 

combination of soils and mixed pine-hardwoods assures continued high levels of quality forest outputs 

for expected climate changes in this region. 

Pine site index is usually greater than 100 feet on 

most second bottoms and river terraces throughout 

the Soclth, with the exception of the Mississippi 

Delta and other broad floodplains. In mixture with 

the native hardwoods, these ''hardwood sites" of 

today once supported many large individual pines 

that were cut during Colonial settlement (Braun 

1950). With the unceflainties today of regenerating 

quality bottomland hardwoods such as cherrybark 

oak, a feasable management option is to plant 

pines on such sites, permitting natural hardwood 

regeneration to develop in mixture with the pine. 

The landowner then has the opportunity to produce 

quality pine saMtimber at half the rotation age of 

hardwoods, wi"lout diminishing either wildlife 

habitat or the value of the stand to develop quality 

hardwood crop trees for the future. The introduction 

of loblolly pine in particular on such bottomland 

sites should be a sound precaution against a warming climate with possibly more frequent droughts. 

In any case, the diversity of a pine-hardwood mixture adds more options on bottomlands than do 

hardwoods alone in an uncefiain future climate. 

CONCLUSION 

Multiple-use foresrnanagement is enhanced, and 

choices are amplified for both economic utilization 

and habitat presewation, by the occurrence and 

maintenance of mixed pine-hardwood stands on 

the widest diversity af sites. The more diverse are 

sites, the more potential for mixtures of forest 

species, and therefore the greater the possible 

management outputs. With the added uncertainties 

of forest responses to expected climate changes 

over the next 50 years, site quality will doubtless 

play an even greater role in determining forest 

habitat uses in the future. 
LITERATURE CITED 

Barrett, J. W., ed. 1980. Regional silviculture of the 

United States. New York: John Wiley and Sons. 

551 pp. 

Bolin, B.; Doos, B.R., eds. 1986. The geenhouse effect: climate change and ecosystems. New York: 

John Wiley and Sons. 541 pp. 

Braun. E. L. 1950. Deciduous forests of eastern 

North America. Philadelphia: The Blakiston Co. 

596 pp. 

Cairns, J., Jr., ed. 1988. Rehabilitating damaged 

ecosystems. Boca Raton, FL: CRC Press. 334 pp. 

Evans, D. L.; Burns, P.Y.; Linnartz, N.E.; Robinson, 

C. J. 1983. Forest habitat regions of Louisiana. 

Louisiana Agricultural Experiment Stat ion. Res. 

Rep. No. 1. 23 pp. Map supplement, scale 

1 : 1,000,000. 

Hodgkins, E. J.; Golden, M.S.; Miller, W.F. 1979. 

Forest habitat regions and types on a photomorphic-physiographic basis: A guide to forest site 

classification in Ala bama-M ississippi. Alabama 

Agricultural Experiment Station and Mississippi 

Agricultural and Forest Experiment Station. 

Southern Coop. Bull. 210. 64 pp. Map supplement, scale 1 :1,000,000. 

Manabe, S.; Wetherald, R.T. 1986. Reduction in 

summer soil wetness induced by an increase in 

atmospheric carbon dioxide. Science 232:626- 

628. 

Mann, R. 0.; Taylor, R.M.; Sims, D.H. 1979. 

Guidelines for pine-hardwood management on 

the National Forests in Mississippi. U.S. Department of Agriculture, Forest Service, Southern 

Region, Atlanta, Ga. 15 pp. 

Martin, W. H., 111. 1971. Forest communities of the 

Great Valley of East Tennessee and their relationship to soil and topographic properties. Ph.D. 

Dissertation, University of Tennessee, Knoxville. 

387 pp. 

Millar, C. I.; Ford, L.D. 1988. Managing for nature 

conservation, from genes to ecosystems. Bioscience 38:456-457. 

Myers, R. K.; Zahner, R.; Jones, S.H. 1986. Forest 

habitat regions of South Carolina. Clemson 

University Department of Forestry. Res. Series 

No. 42. 31 pp. Map supplement, scale 

1 :1,000,000. 

Pehl, C. E.; Brim, R.L. 1985. Forest habitat regions 

of Georgia. Landsat 4 imagery. Georgia Agricultural Experiment Station. Spec. Pub. No. 31. 12 

pp. Map supplement, scale 1 : 1,000,000. 

Sims, D, H.; McGee, C.E.; Galloway, J.; Rickman, 

B. 1981. Mixed pine-hardwood stands--a lowcost option for reforestation. Forest Farmer 

40(10):fO-11, 16-17. 

Smalley, G. W. 1986a. Site classification and evaluation for the Interior Uplands: Forest sites of the 

Cumberland Plateau and Highland Rim-Pennyroyai. Tech, Publ. R8-TP9. Atlanta, GA: U.S. 

Department of Agriculture Forest Service, 

Southern Forest Experiment Station and 

Southern Region. 518 pp. 

Smalley, G. W. 1986b. Landforms: The basis for 

classifying and evaluating forest sites in the Interior Uplands of the eastern United States. In, 

Procedings of a workshop on forest site classification methods. IUFRO Working Party S1.02.06; 

Oct. 7-1 0, 1985. Fredericton, New Brunswick, 

Can. pp. 11 4-1 42. 

Smalley, G. W. (in press). Classification and evaluation of forest sites on the Natchez Trace State 

Forest, State Resort Park, and Wildlife Management Area in West Tennessee. Gen. Tech. Rep., 

U.S. Department of Agriculture, Forest Service, 

Southern Forest Experiment Station, New Orleans, LA. 

Spurr, S. H.; Barnes, B.V. 1980. Forest ecology. 3rd 

Ed. New York: John Wiley and Sons. 687 pp. 

Wilson, E. O., ed. 1988. Biodiversity. Washington, 

DC: National Academy Press. 521 pp. 

Zahner, R. 1982. Productivity and benefits of young 

hardwoods in mixed pine-hardwood stands. In, 

Proceedings, Tenth annual hardwood symposium of the Hardwood Research Council. 

Cashiers, NC, pp.84-91. 

Zahner, R. 1984. Soils and climate of the loblolly 

pine ecosystem, west region. In, Proceedings, 

Symposium on the loblolly pine ecosystem (west 

region), ed. by B. L. Karr, J. B. Baker, and T. 

Monaghan. Mississippi State University, Mississippi Cooperative Extension Service, and U.S. 

Department of Agriculture Forest Service, 

Southern Forest Experiment Station. pp. 17-31 . 

Zahner, R.; Harris, R.H. 1984. Wood fuel production 

from young Piedmont oak stands of sprout 

origin. Forest Products Journal 34: 34-38. 
APPLICATION OF LANDSCAPE ECOSYSTEM 

CLASSIFICATION IN IDENTIFYING PRODUCTIVE 

POTENTIAL OF PINE-HEaRDWOOD STANDS 

Steven M. ones' 

,-The concept of site as the basis for determrning silvicultural and forest management 

practices is unquestioned. The need for site classification of forest land has been recognized for 

decades. Yet, the ability to recognize sites with similar capability is possibly the greatest deficiency in management and silviculture The landscape ecosystem approach expresses the interrelationships between (1 j vegetation and landform, (2) vegetation and soils, and (3) landform and 

soils. In developing the classification, the complex gradients of an area are broken into ecosystem units that recur In the landscape. The ecosystem units (sites) can be distinguished by 

landform, soils, and vegetat~on. This approach has been successfully applied within the Coastal 

Plain and Piedmont of South Carolina and is useful in identifying the productive potential of sites 

where management for pine-hardwood mixtures is desirable. 

INTRODUCTION 

Within a given physiographic region, the three 

basic ecosystem components are landform, soils, 

and vegetation. Traditionally, approaches to site 

classification have stressed either landform, soil, or 

vegetation. Users often overlay single factor classificat ions to produce a component classification. It 

should be understood that this does not produce 

an ecological classification because the Interrelationships are unknown. Classifications systems that include climate, soils, landform, and vegetation have 

been developed and are in use but are not necessarily ecological (Rowe 1 978). 

An ecological classification expresses the interrelationships (1 ) between vegetation (overstory, understory, and groundcover) and landform, (2) 

between vegetation and soils, and (3) between 

landform and soils (Barnes and others 1982). The 

influence of landform and soils on the composition, 

size, and productivity of vegetation can only be understood when their relationships to vegetation is 

known. Likewise, silvicultural interpretations from 

landform and soil factors are dependent on 

knowledge of the interrelationships with vegetation. 

The term landscape is used as a modifier to emphasize that ecosystems are geographic units extending horizontally over the land (Barnes 1989). It 

is the units of land with similar productive potential 

that we are striving to identify. We must provide the 

land manager with the information to identify each 

homogeneous landscape unit. This can only be 

achieved by considering landform as the key component used simultaneously with easily recognized 

attributes of soils and vegetation as a check-andbalance system. 

'~ssistant Professor. Department sf Forestry, Clemson 

University, Clemson, SC. 

Barnes (1 982) and Albert (1 986) demonstrated the 

practical use of landscape ecosystem classification 

in Michigan. The purpose of this paper is to 

demonstrate this approach to classification of 

forestland in the southeastern United States and to 

show its use in identifying sites desirable for pinehardwood management. 

METHODS 

The classification approach has been applied in two 

separate studies within South Carolina. One was 

conducted within the Upper Loam Hills Region and 

Sandhills Region of the Hilly Coastal Plain Province 

and a second within the Midlands Plateau Region of 

the Piedmont Province (Myers and others 1986). 

Forest stands representing the full range of upland 

and bottomland site conditions were sampled 

within the Hilly Coastal Plain Province. Within the 

Piedmont Province only the range of upland conditions were sampled. In both studies, relatively undisturbed steady state or near steady state stands 

were selected to identify the interrelationships with 

soil and landform variables. The classification was 

then applied to disturbed or successional stands. 

Over 200 stands have been sampled to date. 

Sampling on 0.1 acre plots included quantitative 

vegetation measurements, correlation of soils, 

description of soil morphology, particle size distri bution (in the Piedmont), slope position, aspect, and 

landform type. Data were analyzed and vegetative 

classifications developed through multivariate 

analysis techniques (ordination and cluster 

analysis). Soil and landform data were related to 

the vegetative classifications through informal, 

visual or imperical recognition of pattern in variables and through discriminant analysis procedures. Species associations that are characteristic 
a0 tt. 

80 in. 

Armk Pakudrdta Olosunnk Ourrtzlpummcwrts 

WMult* RI.ul~lt8 Wt.udaritS 

AqJc Haphdult. 

TYW 

krk R-8 ~~~udult* Figure 1 .--Landscape ecosystems model for the 

Hilly Coastal Plain Province of South Carolina. 

of a certain set of environmental conditions were ecosystem unit is associated with a unique set of 

identified through synthesis table construction. Plot landform and soil conditions. The major variables 

design, measurements, and analytic procedures controlling productive potential are thickness of the 

have been described in detail elsewhere (Jones and sandy epipedon, internal drainage, and landform 

others 1 984; Jones 1 988). type (table 1 ). Conditions ranged from xeric thick 

sands to poorly drained alluvial bottoms. Since 

RESULTS vegetation is an expression of environmental condiHillv Coastal Plain Model tions, the composition and productivity of vegetation is unique for each landscape ecosystem unit. 

Within the Hilly Coastal Plain Province, seven Detailed descriptions of the soil, landform, and 

landscape ecosystem units were identified across vegetation for each landscape ecosystem unit are 

an environmental gradient which was interpreted as published elsewhere (Jones and others 1981 ; Jones 

a moisture gradient (figure 1). Each landscape and others 1984; Van Lear and Jones 1987). 

Table 1.--Classification of landscape ecosystem units for the 

Hilly Coastal Plain Province 

UPLAND LANDFORMS 

I. Sandhills 

A. Sandy surface >80 inches (~uartzi~samments] 

1. Turkey oak - dwarf huckleberry 

11. Flats arid gentle slopes 

A. Sandy surface 40-80 inches thick (Grossarenic 

Paleudults) 

2. Bluejack oak - dwarf post oak 

B. Sandy surface 20-40 inches thick (Arenic Paleudults) 

3. Blackjack oak - deerberry - broomsedge 

C. Sandy surface <20 inches thick (Typic Paleudults) 

4. White oak - post oak 

111. Moderate to steep slopes 

A. Sandy surface (20 inches thick (Typic Paleudults and 

Typic Hapludults) 

5. White oak - dogwood - pipsissewa 

BmMLAND LANDFORMS 

IV. Well-drained and moderately well-drained alluvial terraces 

A. Gray mottles (low chroma) present only in lower part of 

the soil profile; no gray layers present (Typic 

Hapludults and Aquic Hapludults) 

6. Sweetgum - red maple - redbay 

V. Poorly-drained alluvial terraces 

A. Gray (low chroma) layers present (Aeric Paleaquults and 

Typic Albaquul ts ) 

7. Yellow-poplar - swamp tupelo - dog-hobble 
Associated with the environmental gradient defined Piedmont Model 

by the 7 landscape ecosystem units was a productivity continuum. This continuum is most easily expressed in terms of site index for loblolly (- 

taedir) and longleaf pines (e. gitlustrid (figure 2). 

Site index at base age 50 years for longleaf pine 

ranged from approximately 55 to 75 feet. 

Landscape ecosystem units 1 and 2 were considered most appropriate for longleaf pine management. Loblolly pine site index ranged from 80 to 

105 feet across landscape ecosystem units 3 

through 7. Site index for landscape ecosystem unit 

7 actually decreases due to poorly drained conditions. 

P. taeda 

S.L = QO+ 

Within the Piedmont Province, 5 landscape ecosystem units were identified within upland landforms 

on gneiss-schist derived parent material. This 

model did not include those landscapes associated 

with gabbro-diabase or Carolina slate because 

relationships are altered on these sites, Figure 3 

represents some of the possible combinations of 

landform and soil conditions resulting in these 5 

units. 

80 in. 

7 

Typic Haptudcdtr Typic Tygc Arenic Pabudults Grossarenk Quarttlpmmmdnts 

Pakudcdts Paleudults Pakudults 

Typic 

MC Paleaquults Hapiudultr Figure 2.--Ranges in site-index for longleaf (Pin& 

TYMC ~fbaquults aalustris) and loblolly (e. taedia) pines for each 

landscape ecosystem unit of the Hilly Coastal Plain 

of South Carolina. 

P. plrtmm 

$8. = 60-75 

The five landscape ecosystem units occurred 

across a range of site conditions extending from 

P. taeda 

S.L = 90-105 

P. pallrsbls 

SL < 60 

SUBMESIC* Q. RUORA - 0. ALBA - GERANIUM MACULATUM 

INTERMEDIATE* 0. ALBA - 0. RUBRA - SMILACINA RACEMOSA 

P. taeda 

s.1 t 65-90 

SUBXERIC* Q. ALBA - 0. COCCINEA - VACCINIUM STAMINEUM Figure 3.--Landscape ecosystems model for the 

XERIC- Q. STELLTA - a. VELUTINA - VACCINIUM VACILLANS Piedmont Province of South Carolina. 

P, taeda 

SL = 80-85 
Table 2,--Classification of landscape ecosystem units for the 

Piedmont Province: relatively unaltered soils 

I. Flats to slight slopes; or slopes: upper-slope positions 

A, Clayey subsurface soils; clay horizon witllin 12 inches 

of soil surface 

1. Post o& - black oak - lowbush blueberry 

B. Clay to smdy clay subsurface soils; fine-textured 

horizon 12 to 24 inches within surface 

2. White oak - scarlet oak - deerberry 

11, Slopes: mid-upper to mid-slope positions; 

southerly/westerky aspects 

A. Clayey subsurface soils; clay horizon within 12 inches 

of soil surface 

I. Post oak - black oak - lowbush blueberry 

B. Clayey to sandy clay subsurface soils; fine textured 

horizon 12 to 24 inches within surface 

2. White oak - scarlet oak - deerberry 

C, Clay loam to sandy clay loam subsurface soil; fine 

textured horizon 12 to 24 inches within surface 

3. White oak - northern red oak - false solomons seal 

111, Slopes: mid-lower; southerly/westerly aspects 

A. Clayey to sandy clay subsurface soils; fine textured 

horizon 12 to 24 inches within surface 

2. White oak - scarlet oak - decrberry 

B. Clay loam to sandy clay loam subsurface soil; fine 

textured horizon 12 to 24 inches within surface 

3. White oak - northern red oak - false solomons seal 

IV. Slopes: mid-upper to mid-slope positions; 

northerlyleasterly aspects 

A. Clayey subsurface soils; fine textured horizon within 12 

inches of surface 

2. White oak - scarlet oak - deerberry 

B. Clay loam to sandy clay loam subsurface soil; fine 

textured horizon I2 to 24 inches within surface 

3. White oak - northern red oak. - false solomons seal 

V. Slopes: mid-lower; northerly/easterly aspects 

A. Clay loam to sandy clay lorn subsurface soil; fine 

textured horizon 12 to 24 inches within surface 

4. Northern red oak - white oak - wild geranium 

VL. Slopes: lower; any aspect 

A. Clay loam to sandy clay loam subsurface horizons; fine 

textured horizon 12 to 24 inches within surface 

4,Northern red oak - white oak - wild germium 

8. Smdy low subsurface horizons at my depth 

5,Arnericm beech - northern red oak - christmas fern 

xeric upland flats and upper slopes ta mesic: lower 

slopes Thus, the endpoints of an environmental 

gradient were defined by extremes in landscape 

position. This environmental y radient was interpreted as a soil moisture gradient and could be 

characterized by the csmbination of slope position, 

aspect, depth to clay or rock, and texlure of wbsurface horizon (table 2). Xeric conditions (landscape 

ecosystem unit 1 ) were associated with high 

landscape positions, southerly and westerly 

aspects, and heavy clay teaures ar rock close to 

the soil surface, while mesic conditions (unit 5) 

were associated with low landscape positions, northerly and easterly aspects, and soils with loamy 

strlasudaee horizons. A vegetatianal continuum 

was associated with the environmental gradient 

with distinct species groups for each landscape 

ecosystem unit. Detailed descriptions sf the soil, 

landform, and vegetation for each landscape 

ecosystem unit are available elsewhere (Jones 

1988a; Jones 198839). 

DlSCUSS1(5E9 

It is obvious that not afl sites are suitable candidates for growing miaures al' pines and 

hardwoods. A general "rule of rhumb" historically 

held by foresters has been to manage for pines on 

the least productive and intermediate sites and 
manage for hardwoods on the most productive bottomland sites or mesic coves. In general, the 

southern pines compete aggressively against most 

hardwood regeneration on xeric sites (Nix and 

others 1989). As site quality improves, hardwood 

regrowth will be more vigorous until pine survival is 

reduced on the most productive sites (Sims and 

others 1981 ). 

In consideration of natural competition strategies, 

the logical choice for the regeneration of pinehardwood mixtures is those sites which are intermediate in productive potential. In the Hilly Coastal 

Plain model, the classification units 1,2, and 3 are 

naturally occupied by undesirable hardwood 

species, such as turkey oak (Q. Iaevis), blue-jack 

oak (Q. incana), dwarf post oak (Q. ~retu), 

and blackjack oak (8. marilandica). Classification 

units 6 and 7 are alluvial bottoms where hardwoods 

are the preferred species due to equipment limitations and potentially low pine survival due to competition from hardwoods and other woody 

understory species. Classification units 4 and 5 are 

occupied by desirable hardwood species and potential for growth is adequate to compete with the 

pines. Southern red oak ((a. falcata) is a component of heavily disturbed or successional stands, 

while white oak (Q. aiba) is a component of those 

stands that are late successional or near steady 

state. 

Within the Piedmont, the landscape ecosystem 

model identifies the classification units 1 and 2 as 

relatively low in productive potential. Site index for 

white oak was estimated to range from 60 to 70 on 

classification unit 1 and from 65 to less than 80 on 

classification unit 2. These xeric and subxeric sites 

are not considered optimal for regeneration in pinehardwood mixtures because the pines are likely to 

dominate at an early age (Nix and others 1989). 

Classification units 4 and 5 are considered quality 

hardwood sites. Site index for white oak on classification unit 3 was estimated to range from 80 to 

90 feet. These sites were considered intermediate 

in soil water status relative to the mesic and xeric 

sites and have the greatest potential to regenerate 

in favorable mixtures of pines and quality 

hardwoods. 

Landscape ecosystem classification has an advantage over other classification approaches in the 

ability to predict productive potential from the permanent features of landform and soil even though 

the vegetation component is absent. For example, 

Hilly Coastal Plain classification unit 4 is most often 

in agricultural crops; however, these upland flats 

can be identified and mapped by the presence of 

less than 20 inches of sand over sandy clay loam. 

Traditionally, foresters have used existing stand conditions (species composition, form, and growth) as 

criteria to judge site quality. This approach can 

lead to misclassifications when stands have a long 

history of being high-graded. For instance, Phillips 

and Abercrombie (1 987) reported lower volumes of 

hanrested timber on sites capable of relatively high 

productivity when compared to lower quality sites. 

Stand conditions prior to harvest gave the impression that the better quality sites were of low quality 

(Abercrom bie 1987, personal communication). Soil 

conditions were used as a more accurate measure 

of productive potential. 

IMPLICATIONS 

Landscape ecosystem classification has valuable 

application both in research and management. As 

we strive to develop regeneration techniques 

directed at achieving pine-hardwood mixtures, it is 

imperative that site quality be a prime consideration 

in experimental design. The ability of researchers 

to make technology transfers with predictable 

results is dependent upon identification of sites with 

equivalent productive potential. Although this is a 

simple and widely recognized concept, it is all too 

often ignored. Reliable technology transfer requires 

testing regeneration techniques and developing 

growth and yield models for each classification unit, 

an approach currently adopted through cooperative 

efforts between Clemson University and the 

Southeastern Forest Experiment Station. 

LITERATURE CITED 

Albert, D. A.; Denton, S R.; Barnes, B. V. 1986. 

Regional landscape ecosystems of Michigan. 

School of Natural Resources, University of 

Michigan, Ann Arbor, Michigan. 32p. + map. 

Barnes, 6. V.; Pregitzer, K. S.; Spies, T. A.; 

Spooner, V. H. 1982. Ecological forest site classification. Journal of Forestry 80(8):493-498. 

Barnes, 6. V. 1989. Old-growth forests of the northern lake states: A landscape ecosystem 

perspective. Natural Areas Journal 9(1):45-57. 

Jones, S. M. 1988a. Old-growth forests within the 

Piedmont of South Carolina. Natural Areas Journal 8(1):31-37. 

Jones, S. M. 1988b. Old-growth, steady state 

forests within the Piedmont of South Carolina. 

Ph.D. Dissertation. Department of Forestry, Clemson University, Clemson, SC. 83 pp. 

Jones, S. M.; Van Lear, D. H.; Cox, S. K. 1981. 

Major forest community types of the Savannah 

River Plant: a field guide. Savannah River Plant, 

National Environmental Research Park Program, 

U.S. Department of Energy SRO-NERP-9. 79 p. 
Jones, S. M.; Van Lear, D. H.; Cox, S. K. 1984. A 

vegetation-landform classification of forest sites 

within the upper Coastal Plain of South Carolina. 

Bulletin of the Torrey Botanical Club 1 1 1 (3): 349- 

360. 

Myers, R. K.; Zahner, R.; Jones, S. M. 1986. Forest 

habitat regions of South Carolina. Clemson 

University, Department of Forstry Research 

Series No. 42. 31 p. + map. 

Nix, 1. E.; Ruckfeshauss, T. F.; Jones, S. M. 1989. 

Early crop tree presence in upland pinehardwood stands related to site quality and 

preharvest stand composition. [These Proceedings]. 

Phillips, D. R.; Abercrombie, J. A., Jr. 1987. Pinehardwood mixtures -a new concept in 

regeneration. Southern Journal of Applied 

Forestry 1 1 (4) : 1 92-1 97. 

Rowe, J. S. 1978. The common denominator of land 

classification in Canada: an ecological approach 

to mapping. p. 195-1 98 In: Proc. Ecological Classification of Forest Land in Canada and 

Northwestern U.S.A. For. Ecol. Working Group, 

Can. Inst. Forestry and Centre for Continuing 

Education. Univ. British Columbia, Vancouver. 

Sims, D. H.; McGee, C. E.; Galloway, J.; Richman, 

5. 1 981 . Mixed pine-hardwood stands--a low cost 

option for reforestation. Forest Farmer, Sept. 

1981 :lo-1 1,16-17. 

Van Lear, D. H.; Jones, S. M. 1987. An example of 

site classification in the southeastern coastal 

plain based on vegetation and land type. 

Southern Journal of Applied Forestry 11 (1):23-28. 
BIOMASS ACCRUAL IN FBUR-YWR-OLB 

PINE-HARDWOOD REPRODUCTION ACROSS A SOIL 

MOgSTURE GWDIEMT 

John C. Agdams and Kenneth W. ~arrish" 

Abstract -Pine reel oak s&eelgum and total biomass for four-year-old seedlings was 

sampied across a so11 rno~sftfre gradient from the top of a hill down into a small stream bottom There was no difference in biomass productron for total or with~n rndividual species 

from the bonom to the lop of the h~ii There was also no drfference In slze (diameter and 

height) iivrthir, ind8v~duai species Or: these sites hardvdoods had grown at faster rates than 

the ptne at age four Regression analysts revealed some positive correlation between soil 

fertility and hardwood biomass and subsoil moisture and plne btomass However, these 

varratiens did not appear to he related to elevation of the sample plots 

INTRODUCTION 

Most southern pine management has been directed 

toward production in even aged-pure stands. 

These stands are thought to be more productive 

(economically), with the less desirable hardwoods 

removed through the use of fire, mechanical means 

or herbicides. Release operations (Smith 1986) 

provide foresters with techniques to manage forests 

and control undesirable vegemaon. 

During the last 10-1 5 years, concerns have been 

raised about the use of fire and herbicides in forest 

management. Smoke management and liability 

concerns have kept many managers from using fire 

to control hardwood encroachment in pine stands. 

In addition, restrictions on the use? of herbicides 

and the lack of suitable chemicals have also 

prevented the control of hardwoods in pine stands. 

As a result, there has been an increase in the number of acres in the mixed pine-hardwood type. In 

1985, there were approximately 26,908,000 acres of 

forest in the South classified as mixed pinehardwoods (USDA Forest Service 4 988). If this 

trend continues, many mare acres sf young stands 

will be in this type. 

Policy objectives on public lands have been 

modified to include the management 04 mixed pinehardwood stands, Public opinion has dictated the 

use af silvieultural practices that increase th, 0 occurrence sf the miaacturre. However, change to the pinehardwsod mixdures has been done with little knswledge of the regeneration, grokvth, and silvicadltural 

management of these complex c.cslsgical cornmunities. 

The forests of north-central Louisiana are generally 

classified as pine timber types. However, within 

this region are also found numerous creeks and 

small river floodplains that support primarily 

hardwoods, but also scattered pine. These 

hardwood sites are usually narrow and are surrounded by the uplands which contain a greater 

percentage of pine. The accepted belief for these 

sites is that the bottoms are more productive 

(higher site index) than are the upland sites, and 

that pine will have superior growth compared to the 

hardwoods. 

The purpose of this study is to provide information 

on the growth, development, and biomass accumulation of a four-year-old pine-hardwood mixture that extends from a bottomland to an upland 

site. 

METHODS AND PROCEDURES 

The study site was located in north central 

Louisiana and is an area typical of the upper Gulf 

Coastal Plain. The site had been clearcut, chopped 

and burned, and planted with loblolly pine, 

However, the planting was a failure and most sf the 

seedlings occupying the study site originated as 

natural reproduction. 

Species cornpasition was a mixbure of lobloliy pine 

and a group of less important species listed as miscellaneous. In this study, loblolty and shortleaf pine 

were grouped together as pine, and red and 

cherrybark oak were grouped as red oak. 

'~rofessor of Forest Genetics and Sii~icuiaiure and As 

sistant Prolessor of Forest SQIJS fka~pe~t~veI")lcc~~~ 

of Forestry Loursiana Tech Un~versid~ Ruston LA 
The stand was more than well stocked with 66,040 (Knudsen and others 1982) were measured. Soil 

seedlings and sprouts per hectare. There were pH was determined on a 1 :4 soiliwater suspension. 

5,080 water oak, 3,810 red oak, 3,302 sweetgum, 

18,034 miscellaneous hardwood, and 35,814 pine Analysis of DaQ 

per hectare. Included in the count was a large num- The closeness of the linear relationship between 

ber of one- and two-year-old loblolly pine seedlings. variables was estimated with correlation coefficients 

Site index was measured on the upland and the bot- using the PROC CORR procedure of SAS (SAS 

tom for mature loblolly pine growing in an adjacent 1985). The Stepwise procedure was then used to 

stand. Soil conditions and topography were essen- search for appropriate multiple regression models 

tially the same as the study site. Site index (age 50) to relate site variables to tree productivity. 

for the bottom was 33.5 meters and at the top of the 

slope was 27.5 meters. 

Biomass 

Biomass sampling was done the first week in June 

1988 on a transect from the top of the hill down into 

the bottom (a 15 meter change in elevation over a 

surface distance of 360 meters). Nineteen plots 

(one meter radius) were placed at 20 meter intervals. All above ground woody vegetation was 

removed, separated by species groups, and 

prepared for drying. Samples were oven dried at 

700 C until equilibrium was reached and weighed to 

determine biomass dryweight. 

From each sampling plot on 0 azimuth, the first two 

individuals of pine, water oak, sweetgum and red 

RESULTS 

sQ!k? 

Soil drainage and moisture. Soil drainage class, 

as determined by depth to gray mottles, ranged on 

the study plots from well-drained to somewhat poorly drained. Unexpectedly, some of the shallowest 

depths to gray mottling occurred at midslope (plots 

12-1 5), suggesting side slope seepage of a perched 

water table (figure 1). The higher potassium levels 

and moisture content at the time of sampling in the 

subsoil (90-1 00 crn) of these plots are also evidence 

of water seepage at midslope with potassium being 

transported in the groundwater (table 1). As expected, the depth to gray mottles was relatively shalRELATIVE ELEVATION AND GRAY MOTTLES 

oak were collected for measurementof height, surf ace ------ gray mottles 

groundiine diameter, and dryweight. These trees 20 

were measured to provide information on in- - 

E dividuals within species from the top of the hill into 

the bottom. 0 t 

At the center of each plot, the soil was sampled with 

a bucket auger. The depth to the first gray mottles 2. 

was observed and recorded during the auger (O 4 

boring. Soil samples were collected from 0-10, 10- Q) 

20 and 90-100 centimeter depths. Soil moisture u 

content of the samples was determined gravimetri- o............,... ,. 1 2 3 4 5 6 7 1) 9 10 11 12 13 14 15 18 17 ill 19 

cally. Total Kjeldahl nitrogen (Bremmer and Mul- plots (Bottom to TOP) 

vaney 1982); extractable phosphorus (Olsen and 

Sommers 1982), and exchangeable potassium 

Figure 1 .--Relative elevation and the depth of mottles for the study area. 

Table 1. Mean values for selected soil properties of the study 

area. 

Depth N P K PH Soil 

Moisture 

0 _o ----- (pet dry) 

0-10 0.15(0.109)~ 5.8(2.61) 94(48.2) 4.9(0.20) 13.6(2.87) 

10-20 O.08(0.047) 2.4(1.35) 58(26.8) 4.9(0.32) g.l(Z.96) 

90-100 0.04(0.015) O.Q(O.75) 95(47.4) 4.5(0.26) 18.0(4.85) 

?Ialue in parenthesis is standard deviation. 

7 1 
low in plots at the bottom of the slope in the alluvial 

deposit. The driest soil moisture regime (based on 

depth to gray mottles) was on plots at the top of the 

slope and those below the seepage area on the side 

slope. However, the only trend in subsoil moisture 

content among plots was higher moisture content in 

plots 12 through 15, indicative of side slope 

seepage as stated earlier. Soil moisture at the time 

of sampling was least in the 10-20 centimeter depth, 

rangirsg from 4-1 3 percent of dry weight. Due to 

recent precipitation events, the surface soil (0-1 0 

cm) moisture was somewhat higher, ranging from 9 

to 19 percent moisture content. Subsoil (90-1 00 

cmf moisture was highest, ranging from 12 to 32 

percent. 

Chemical propefiies. Total Kjeldahl nitrogen, 

while extremely variable, tended to decrease with increasing depth in the soil profiles, consistent with 

decreasing organic matter with increasing depth. 

There was no apparent relationship between total 

nitrogen and plot location. 

Extractable phosphorus content generally 

decreased with increasing depth in the soil profiles. 

Phosphorus content of the subsoil (90-1 00 cm) was 

extremely low, below detectable levels in some 

samples. This is consistent with Ultisols of the 

region, which are often deficient in phosphorus for 

optimum tree grovvth. There was no apparent trend 

with exrractable phosphorus and location. Exchangeable potassium did not seem related to the 

depth. Potassium was considerably higher in the 

subsoil of plots 12 through 15 as stated earlier. 

There was also no apparent trend in soil pH in relaRegression equations relating individual species 

plot biomass to measured soil properties are summarized in table 2, The models revealed some positive correlations between hardwood biomass and 

soil fertility levels, especially nitrogen and phosphorus. The equation for pine suggested that subsoil (90-1 00 cmf moisture had a positive correlation 

with biomass. 

The mean total woody biomass on the study area 

was approximately 16.8 metric tons ham1 Biomass 

by species totals (table 3) were not different among 

the plots, regardless of the plot location (figure 2). 

There were also no among plot differences detected 

for biomass of individual tree species. No individual groups, including the miscellaneous 

group, showed any substantial trend in relation to 

plot location. 

PLOT BIOMASS TOTALS 

PLOTS (BOTTOM TO TOP) 

tion to plot location or depth. Soil pH ranged from Figure %-Total plot biomass from the bottom to the 

4.1 to 5.3. top of the hill. 

Table 2. Summary of regression models for woody biomass and 

a soil properties . 

Dependent Variable Independent Variable(s) Probability r 

2 

Pine Biomass ~oisture (90-100) b, K(10-20) 0.009 0.47 

Red Oak Biomass F(0-10) 0,674 0.18 

Water Oak Biomass N(10-20), P(0-10) 0.001: 0.72 

Sweetglum Biomass N(g0-loo), N(0-10) 0,004 0.52 

M~SG Biomass pH(l0-20) , K(O-10) 0,018 0.41 

Total Biomass pH(10-20) 0,026 0.27 

%ased on individual plot biomass values. 

b~alue in parenthesis is depth of sampling in centimeters. 
Table 3. Biomass, diameter and height by species for four-year-old 

mixed pine-hardwood reproduction. 

Mean Mean Mean 

Species Biomass Diameter Height 

(Tons ha- ) 1 m rn 

Pine 5.26 2.90(0.803)~ 2,48(0,408) 

Red Oak 1.31 3.16(0.926) 3.22(0.669) 

Water Oak 2.68 2.63 (0.446) 3.45(0+523) 

Sweetgum 1.96 3.60(0.860) 3.48(0.720) 

Total 16.03 

value in parenthesis is standard deviation. 

The hardwood species averaged almost one meter 

tailer than the pine on the study area. This is the spposite of findings of Phillips and Abercrombie 

(1 987) for Piedmont mixed pine-hardwood stands. 

Diameters (groundline) were more variable, with 

water oak having the smallest mean diameter followed in ascending order by pine, red oak and 

sweetgum (table 3). There was no difference by 

species in height or diameter regardless of the location of the measured individuals on the slope. 

These data indicate that the four species were growing at the same rate whether at the bottom on somewhat poorly drained soils or at the top on 

well-drained soils. 

DISCUSSION 

In this study of four-year-old mixed pine-hardwood 

reproduction, no difference could be detected for 

total biomass, height, or groundline diameter in relation to location on the slope. There was a soil moisture gradient from the bottom to the top of the slope 

as expected (figure 1). Unexpected was the lack of 

effect of this moisture gradient on tree growth. In 

contrast the adjacent 40 to 60 year-old stand of 

loblsiiy showed a six meter diir'erenee in site index 

(bottom vs. hilltop). Since this site quality difference was not expressed in the four-year-old 

reproduction, site factors that would limit growth 

later in the stands rotation had apparently not yet affected the stand. Total seedling numbers were high, 

but no seedling mortality caused by competition 

was observed. This information, combined with the 

lack of growth difference between slope position, 

would suggest that at this stage of stand development the site is not fully occupied and competition 

for soil moisture had not yet become limiting. 

Although the data indicate that no relationship exists between species biomass and slope position, 

the regression equations revealed some correlation 

between soil fertility and hardwood biomass, and 

subsoil moisture content and pine biomass. This 

might imply that on this study area, soil fertility was 

beginning to limit hardwood development and soil 

moisture was beginning to l irnitt pine development 

as the stand begins to fully occupy the site. 

ACKNOWLEDGMENTS 

This research is supported in part by the MclntireStennis Cooperative forestry research program. 

The authors also thank the USDA Forest Service for 

cooperation in this study. 
LITERATURE CITED 

Bremmer, J.M.; Mulvaney, G.S. 1982. Nitrogentotal. pp 595-624. In: R.H. Page and D.R. Keeney 

(eds.) Methods of soil analysis, part 2. American 

Society of Agronomy, Madison WI. 11 59 pp. 

Knudsen, D.; Peterson, G.A.; Pratt, P.F. 1982. Exchangeable and soluble lithium, sodium and 

potassium. pp. 225-246. In: R.W. Page and D.R. 

Keeney (eds.). Methods of soil analysis, part 2. 

American Society of Agronomy, Madison, WI. 

1159 pp. 

Olsen, S.R.; Sommers, L.E. 1982. Phosphorus. pp. 

403-430. In: R.H. Page and D.R. Keeney (eds.). 

Methods of soil analysis, part 2. American 

Society of Agronomy, Madison, WI. 11 59 pp. 

Phillips, D.R.; Abercrombie, J.A., Jr. 1987. Growth 

and development of shortleaf pine-hardwood 

mixed stands four years after regeneration. U .S. 

Forest Service General Technical Report SE4211 62-1 68. 

SAS Institute Inc. 1985. SAS users guide: Statistics, version 5 edition. Cary, NC. 596 pp. 

Smith, D.M. 1986. The practice of silviculture (8th 

ed.). Johr? Wlley and Sons, New York, N.Y. 527 

PP. 

USDA Forest Sewice. 1988. The south's fourth 

forest: alternatives for the future. Forest 

Resource Report 24. 51 2pp. 
FELL AND BURN TO REGENERATE MIXED 

PINE-HARW D STAN=: AN OVlERVI 

RESmRCH ON STANIC) DWELOPMNT 

Thomas A. Waldrop, F. Thomas Lloyd, and James A. Abercrombie, dr.' 

, -The fell-and-burn site preparation technique has been used successfully on the Sumtei kiational Forest in the mountains of South Carolina to regenerate poor-quality stands to productive p~ns-hardwood mixtures Young stands typically have numerous hardwood sprouts, but 

gro.uvth and survival of planted pines are excellent. Despite this success, many questions remain. 

The Southeastern Forest Experiment Station is studying this and other techniques to establish 

pine-hardwood mixtures in the Piedmont. In this region, variations in the fell-and-burn technique 

may be rsquired due to differences in species composition and site. Burning prescriptions must 

be developed to protect the thin root mats, Growth and yield are being projected for mountain 

and Piedmont sites. 

iMTROOUCTl(fdM 

Because demands for softwood and hardwood timber are increasing in the Southeast, forest 

managers and researchers are searching for 

profitable met hods to increase forest productivity. 

One alternative is to place poorly stocked, unmanaged forest lands under some form of management. The Piedmont and mountain regions of the 

Southeastern United States have 39.5 mill ion acres 

of commercial forest land. Over 65 percent of this 

timberland (26.8 million acres) is occupied by 

hardwood sr mixed pine-hardwood stands (Bech'lold and Wuark 1988). Private nonindustrial landowners, who control 72 percent of these stands, 

usually do nag manage their woodlands. 

Since hardwood competition is vigorous in these 

regions, conversion to stands of pure pine requires 

eaensive site preparation. Most landowners have 

choser~ to leave their forests unmanaged rather 

than spend the $150 to $250 per acre required for 

reforestation. The result has been a large acreage 

of poorly stocked stands with large numbers of undesirable stems. lo encourage private landowners 

to manage their forests, low-cost alternatives for site 

preparation must be developed along with projecdians sf Future yields and returns on investments. 

A less expensive alternative to pine plantation 

management is the clattwing af pin@-hardwood mixt bares. A Isw-cost site preparation technique, called 

ter National Forest in South Carolina, over 3,500 

acres on mountain sites have been converted by 

the fell-and-burn technique over the past 9 years. 

For less than $1 00 per acre, including site preparation and planting costs, hardwood sprout growth is 

controlled enough to allow shortleaf pine ( 

echinata Mill.) seedlings to become established and 

grow (Pkiiiips and Abercrombie 1987). In three randomly selected 4-year-old stands, suwival of free-togrow shortleaf pine seedlings was generally over 75 

percent. Hardwood sprouts were numerous, but 

they were generally less than 6 feet tall, whife 

planted shortleaf pines averaged over 8.5 feet tall. 

The success of the fell-and-burn technique is apparent in young stands on the mountains of the 

Sumter National Forest. However, many questions 

remain, including application to new regions, the 

need for intermediate treatments, and stand growth 

and yield. This paper presents an overview of research being conducted by the Southeastern Forest 

Experiment Station's Research Work Unit for the Silviculture and Management of Pine-Hardwood Mixtures in the Piedmont (SE-4105). Silvicult uaal 

techniques proven in the Appalachain Mountains 

will be tested in the Piedmont, and growth and yield 

sf ths new mixed stands will be projected. 

THE FELL-AND-BURN TECHNIQUE 

fell and burn (~bercrohb/e and Sims 1986), has The felt-and-burn technique was described in detail 

been sktceessfarl in the Southern Appalachian Moun- by Abercrornbie and Sims (1 9861, Phillips and 

tains for converting law-quality hardwood stands to Abercrombie (1 987), and Van Lear and Waldtop 

productive pine-hardwood mixtures. On the Sum- (1 988). Briefly, the technique involves clearcuating 

of hardwood or ~ine-hardwood stands and chain- 

'Research Farestar, USBA Forest Service, 

Southeastern Forest Exper~rnent Station, Clemson, 

SC, Project Leader, USDA Forest Servtce, 

S~uthedl~larn I=OIC?S~ Expsrrmsnf Station Clemson, 

SC, and Plrnhsr Management Assistant, USDA 

F~fesl Sewice, Sumref National Forest, Walhalla, 

SC 

saw felling of standing residual stems over 5 feet tall 

in mid-April to early June. At this time in the 

Southern Appalachian foothills of South Carolina, 

most trees are three-quaeers to fully leafed out. 

Timing is critical because the dried leaves and twigs 
are needed as fuel to carry a summer broadcast 

burn. Also. sprout vigor is reduced by cutting when 

carbohydrate reserves in root stocks are in low 

supply, 'flhen trees are cut after they have leafed 

out, twigs and smalt branches dry more quickly 

through transpirational drying (McMinn 1986) and 

the depletion of hardwood carbohydrate reserves 

helps pines that will be planted later to compete for 

growing space. 

Broadcast burns are conducted 4 to 6 weeks after 

residual stems are felled, generally in mid-July to 

early August. The desired burn is a high-intensity 

fire over a moist fuel bed. Burning is generally conducted I to 3 days after a soaking rain when the 

moisture content of 10-hour timelag fuels (114 to 1 

inch in diameter) is 10 percent. At that time, the 

felled stems have sufficiently dried to carry an intense fire but the forest floor and surrounding 

stands are too moist to burn. This timing ensures 

that only a portion of the forest floor will be consumed, leaving a protective cover over the mineral 

soil. Guidelines for broadcast burning safely and effectively in the Southern Appalachians are discussed by Danielovich and others (1987). During 

the winter following burning, improved shortleaf 

pine or loblolly pine (P. L.) seedlings are 

planted on a "i- by 10-foot spacing. 

During 1988, the total cost of regenerating by the 

fell-and-burn technique was $88 per acre. Contracts for chainsaw felling averaged $35 per acre. 

Broadcast burning was conducted by the South 

Carolina Forestry Commission for $9 per acre. 

Planting contracts averaged $27 per acre, while the 

cost of seedlings was $1 7 per acre. 

Summer broadcast burning is probably the more 

beneficial of the two steps in this site-preparation 

technique. Sprouts that develop after chainsaw felling are top-killed by the fire and new sprouts are 

less vigorous. Burning removes over 65 percent of 

the woody fuels less than 3 inches in diameter 

(Sanders and Van Lear 1988), making the site more 

accessible for planting. After planting, the black surface makes green seedlings more visible, ensuring 

a better job of planting. The fire also kills 

aboveground buds on hardwood stumps, forcing 

new sprouts to originate from below ground 

(Augspurger and others 1987). Therefore, these 

new sprouts will be well anchored and of better 

form 

In trials of practical scale, broadcast burns removed 

80 percent of the surface forest floor, but 67 percent 

of the root mat remained intact (Danielovich 1986). 

This roof mat is important for its water holding 

capacity. It acts as a mulch, allowing young pines 

to survive and grow. The root mat also helps 

prevent erosion. Van Lear and Danielovich (1988) 

found that erosion, measured as trapped sediment, 

did not increase in clearcut and burned areas when 

compared to clearcut areas that were not burned, 

Lack of erosion following clearcutting and burning 

was aftributed to large stems and stumps acting as 

debris dams; vigorous shrub and herbaceous 

regrowth; and burning under moist conditions so 

that the root mat remained intact. A summary of 

the effects of the fell-and-burn technique on Appalachian soils is given by Van Lear (1 989) 

To monitor growth and development of stands 

regenerated by the fell-and- burn technique, sample 

plots were installed in the oldest stands on the Sumter National Forest that were site-prepared by the 

fell-and-burn technique and planted with shortleaf 

pine and loblolly pine. To prevent ice damage, 

loblolly pine was planted on sites lower than 1000 

feet above mean sea level while shortleaf pine was 

planted on sites above 1000 feet. Plots were inventoried during the winter of 1987. At that time, the 

oldest shortleaf pine stands were 6 years old and 

the oldest loblolly pine stands were 7 years old. 

From 7 to 10 sample plots, 1/20 acre in size, were 

established at random locations within each of two 

stands for each species. 

Sites planted with shortleaf pine had over 7500 

stems per acre, the majority of which (85 percent) 

were blackgum (Nyssa sylvatica Marsh.), red maple 

(Acer rubrum L.), and other hardwoods (table 1 ). 

Even though hardwoods were numerous, survival 

and growth of planted pines was excellent. Of the 

436 seedlings planted per acre, 83 percent survived 

for 6 years and were free to grow. Planted pines 

averaged 9.4 feet in height while hardwoods were 

generally less than 6 feet tall. 

Lower-elevation sites planted with loblolly pine were 

also dominated by hardwood sprouts (table 2). Of 

the 4,883 stems per acre tallied on study plots, 87 

percent were hardwoods. However, pine survival 

and growth were excellent. Over 95 percent of the 

planted pines survived and were free to grow. In addition, 186 volunteer pines per acre were present. 

Planted and volunteer pines were taller than most 

hardwoods and on some plots a closed pine 

canopy was beginning to develop. Red maple 

sprouts were prolific and dominated the overstory 

on some plots. 

CURRENT RESEARCH 

In 1986, the Southeastern Forest Experiment Station established a Research Work Unit at Clemson, 

SC, entitled "Silviculture and Management of PineHardwood Mixtures in the Piedmont''. Two problem 

areas were identified. The first includes the development and testing of silviculturai techniques to establish pine-hardwood mixtures in the Piedmont. 
Table 1.--Species composition and mean height by species for 6-year-old 

shortleaf pine stands regenerated by the fell-and-burn technique 

Species Stemslacre (pct) 

Mean height 

(feet) 

Planted shortleaf pine 

Natural pines 

Select oaka 

Blackgum 

Red maple 

Other hardwoods 

Total 7,540 (100) 

a Scarlet oak (Quercus coccinea Muenchh.), southern red oak (&. falcata 

Michx.), white oak (&. alba L.), post oak (Q, stellata Wangenh.), black oak (Q, 

velutina Lam.), chestnut oak (Q. prinus L.). 

Table 2.--Species composition and mean height by species for 7-year-old 

loblolly pine stands regenerated by the fell-and-burn technique 

Species Stems/acre (pct) 

Mean height 

(feet) 

Planted loblolly pine 

Natural pines 

Select oaka 

Blackgum 

Red maple 

Other hardwoods 

Total 4,883 (100) 

a Scarlet oak, southern red oak, white oak, post oak, black oak, chestnut 

oak. 
Included in thls problem area are studies of early 

stand development, intermediate treatments such 

as release and thinning, and effects of these treatments on vegetation, soils, and wildlife. The second 

problem area is designed to provide information on 

the productivity of pine-hardwood mixtures. 

Several approaches are being attempted to develop 

prediction models for stand growth and yield. 

Due to the diverse nature of pine-hardwood mixtures and the fact that management of this type is 

retat~vely new, numerous topics have not been 

studied. The following discussion is an overview of 

some of the work being done by the PineHardwood Research Work Unit on the fell-and-burn 

technique. It is not intended as an exhaustive 

review of research needs for pine-hardwood 

management. 

Application in the Piedmont Reaion 

Until recently the fell-and-burn technique had not 

been attempted outside of the Southern Appalachian Mountains. Due to differences in soils, 

topography, climate, and species composition, the 

technique may not work well in the Piedmont 

region. Variations of the technique or other site 

preparation methods may be necessary to establish 

pine-hardwood mixtures in this region. 

A study, funded by the Georgia Forestry Cornmission, was begun in 1987 to test the fell-and-burn 

technique in the Piedmont. Study plots were established on the Dawson Forest in Dawson County, 

GA; the Clemson Experimental Forest in Pickens 

County, SC; and on private land in McCormick 

County, SC (figure 1). Selected sites were on 

Figure 1 .--Fell and burn to convert low-quality 

stands to productive pine-hardwood mixtures: Piedmont study sites. 

predominantly south-facing slopes with stands 

dominated by scarlet oak (Urcu coccinea 

Muenchh.), southern red oak ((a. falcata Michx.!, 

and hickories (Car@ m.). Clearcutting was cornpleted during the winter of 1988. Chainsaw felling 

and broadcast burning were completed in May 

1988 and July 1988, respectively. Loblolly pine seedlings were planted during February 1989. Rather 

than the usual 1 0 by 1 0 foot spacing, pines were 

planted on a 15 by 15 foot spacing (1 93 per acre) 

to allow hardwoods to compete and become a 

major component of the stand. 

Three treatments were imposed in each of seven 

replications: fell and burn, fell only, and burn only. 

The fell only and burn only treatments were selected 

for two reasons. First, they are less expensive than 

felling and burning and may be attractive to private 

landowners. Second, they allow hardwoods a better chance to become a component of the stand. 

Loblolly pine is a vigorous competitor on many 

Piedmont sites, so the combination of felling and 

burning may not be necessary for pine survival. 

Since many landowners do not have the experience 

and resources to burn safely, the elimination of this 

step would be particularly attractive. 

Early results sf this study indicate several differences in applying the fell-and-burn technique in the 

Piedmont. Species composition of corn pet in() 

hardwoods is more variable than on the mountain 

sites of the Sumter National Forest. Study sites on 

the Clemson Experimental Forest are located in the 

Upper Piedmont and have many species similar to 

the Sumter National Forest (table 3). However, 

sourwood (Oxvdendron arboreum L.) and dogwood (Cornus fiorida L.) are more numerous. 

Even though these species will not be major competitors in older stands, they may overtop planted 

pines in early years. McCormick County study sites 

are representative of the Middle Piedmont. The 

dominant species on these plots are sweetgum (LJ 

L.) and naturally-regenerated 

loblolly pine. Sweetgum sprouts prolifically and 

grows rapidly. Both felling and burning may be required to control sweetgum growth enough to allow 

pines to compete. 

Broadcast burning may damage Piedmont sites. 

Because of the history of farming on Piedmont 

sites, root mats there are not as well developed as 

in the mountains. On the Sumter National Forest, 

root mats are often over 3 inches thick, while they 

were less than 1 inch thick on all Piedmont study 

plots. Strict burning guidelines must be developed 

to prevent soil exposure and erosion on Piedmont 

sites. 

Two additional studies have been established in 

these study areas. One will document the effects of 

spring felling and summer broadcast burning on 
Table 3.--Species composition of seedlings and sprouts on two Piedmont sites 

prior to planting. 

Species Clemson Forest McCormick County 

Pines : 

Loblolly 

Shortleaf 

Oaks : 

Scarlet 

White 

Black 

Post 

Other oaks 

Other Hardwoods: 

Blackgum 

Sourwood 

Hickory 

Dogwood 

Sweetgum 

Miscellaneous 

Total 

-------em Stems per acre (pct) ---------- 

sprout vigor. While these treatments are known to 

slow hardwood growth, the degree of reduction has 

not been documented. This study will provide insight into alternatives of the fell-and-burn technique 

that may be needed to allow pines and hardwoods 

to grow together. The other study will document 

the effects of the various treatments on the quality 

of habitat for several wildlife species. Detailed 

descriptions of the vegetation available for browse 

are being compiled. In addition, small mammals 

are being trapped to obtain an estimate of utilization. 

Site Selection 

Success in establishing pine-hardwood mixtures 

with the fell-and-burn technique depends on site 

selection. On sites of low productivity, hardwoods 

are generally absent or grow slowly and have poor 

form. Culturing quality hardwoods on these sites 

would be expensive or, in many cases, impossible. 

Highly productive sites, on the other hand, are best 

suited for hardwoods. Planted pines are quickly 

overtopped by vigorous hardwood sprouts. On the 

Sumter National Forest, the technique has been successful on medium sites - slopes with south to 

southwest aspects and a site index of 65 to 70 feet 

for upland oaks at 50 years. No effort has been 

made to determine the upper and lower bounds of 

site quality for which pine-hardwood mixtures can 

be successful . 

On many sites in the Southern Appalachian Mountains and Piedmont, existing stands are poor indicators of site quality. High-grading, fires, and 

mismanagement have produced low-quality stands 

on sites with high productive potential. To evaluate 

the potential of such sites for pine-hardwood 

management, a classification system based on factors other than standing trees is needed. A 

cooperative study has been established with Clemson University to develop an ecologically based 

classification system for the Piedmont using a technique proposed by Jones and others (1984) and 

Jones (1989). Under this system, site types are 

described as specific combinations of understory 

and overstory vegetation, land forms, and soil 

types. Site types suitable for pine-hardwood mixtures will be identified. 

In the study of the fell-and-burn technique in the 

Piedmont, mentioned above, study plots were established on slopes with south and southwestern 

aspects. In five of the seven replications, however, 

sites ranged from dry upland ridges to moist northfacing slopes and coves. In each case, the entire 
hallrested area was prepared by the fell-and-burn 

technique Additional study plots are being established in these stands on as many site types as possible These plots will be used to validate the 

Piedmont site classification system and to gain insight into the relationship between site quality and 

the success of pine-hardwood regeneration. 

information on stand grovvth and yield is limited for 

pine-hardwood miaures. The small amount of 

repofled research has either viewed the hardwood 

component as a competing understory (Smith and 

Hafley 1987, Burkhart and Sprinz 1984) or has 

focused on relatively short term projections (20 

years or less) using inventory data form pinehardwood stands in the Southeast (Meldahl and 

others 1988). As a result, permanent growth and 

yield plots are being established in the Piedmont to 

develop forecasting systems for pine-hardwood mixtures. 

One study examined the ability of six mixed-species 

models developed for other regions to describe the 

development of young pine-hardwood stands on 

the Sumter National Forest. The models tested 

were SIIVAH (Marquis and others 1984); OAKSIM 

(Hilt 1985), G-HAT (Harrison and others 1986), 

Central States TWIGS (Belcher 1982), GATWIGS 

(Meldahl and others 1988), and FORCAT (VValdrop 

and others 1986). All candidate models under-estimated stem numbers over a 5-year simulation 

period (ages 2 to 7 in loblolly pine mixtures and 1 to 

6 in shortleaf pine mixtures), primarily because 

stem numbers in young clearcuts typically increase 

for several years as sprouting increases and seedlings develop. Another problem dealt with the relative growth rates of hardwoods and planted pines. 

Hardwood vigor is reduced by the fell-and-burn 

technique (Geisinger and others 1989); making it 

easier for pine seedlings "i compete with hardwood 

coppice regeneration. Each model predicted fast 

growth of hardwoods at the expense of pine growth 

and suwival. None of these models was developed 

for young clearcuts in the Southern Appalachians 

or Piedmont, so poor model pedormance was not 

unexpected. 

Formulation of forecasting predictors for early stand 

deveroprnent (prior to crown closure) is important 

because change is rapid, and subtle differences in 

estabiishrnent conditions can dramatically affect the 

percentage of pines capturing a position in the overstory. Once crowns have closed, subsequent changes in species composition are slow and are the 

result of competition and self-thinning instead of the 

relative ability of species for rapid early height 

growh. As a result, a modeling approach is being 

developed on the principles that 1) there will be 

separate model camponents for pre-closure and 

post-closure development stages which are driven 

by different inputs and linked by some measure of 

the size of the pine component at crown closure, 

and 2) both phases will be driven in part by height 

growth and built around a site classification system 

based on aspect, slope position, and depth to the 

maximum clay content (Jones 1989). Details of this 

modeling approach are presented by Lloyd (1989) 

elsewhere in these proceedings. 

Site protection after the fell-and-burn technique 

depends largely on maintaining a thick root mat. 

This root mat protects the soil from erosion and 

acts as a mulch, retaining moisture for planted 

pines. Particularly on Piedmont sites, protection of 

the root mat is mandatory. Observations indicate 

that this mat is not as well developed on Piedmont 

sites, so the margin for error is slim. Little is known 

about the origin and distribution of root mats. 

Research is needed to determine the extent to 

which root mats occur in the Piedmont and the factors that influence their development. 

Prescription guidelines have not been developed for 

broadcast burning on Piedmont sites. On the Sumter National Forest, fuel moisture sticks are used to 

determine when to burn. Generally, when these 

sticks contain 7 0 percent moisture, downed woody 

fuels are dry enough to burn but the forest floor and 

root mat are moist. When stick moisture content is 

below 10 percent, burning becomes risky. Fuel 

moisture sticks may prove useful on Piedmont sites, 

but they are untested. In addition, the relationship 

of fuel moisture, fuel type, weather, slope, and firing 

technique to fire intensity and fire severity must be 

established . 

Scientists of the USDA Forest Service, the University of Georgia, and Clemson University have begun 

a cooperative research effort with the Agricultural 

Research Service in their Water Erosion Prediction 

Project (WEPP). WEPP is a nationwide program to 

develop a physical process-based model of surface 

erosion after disturbance to replace the Universal 

Soil Loss Equation. The initial research efforts in 

the Southeastern Piedmont are to study the effects 

of the fell-and-burn technique. A variety of sites wilt 

be burned by several firing techniques and at varying levels of fuel moisture to produce a range of fire 

severity. This work will determine how soil erosion 

and sediment production are influenced by rainfall. 

fire severity, soil properties, and slope. It will also 

provide preliminary data for developing guidelines 

for broadcast burning in the Piedmont. 
SUMMARY AND CONCLUSIONS 

Low-quality hardwood and pine-hardwood stands 

in the Southern Appalachian Mountains have been 

converted to productive pine-hardwood mixtures by 

the fell-and-burn technique. Since, the technique is 

inexpensive, it may attract private landowners to 

put their unmanaged stands into timber production. 

Introduction of pines to previously unmanaged 

hardwood stands improves stand value and increases management options while maintaining 

quality habitat for several wildlife species. 

On sites at 1000 feet above mean sea level or 

higher, shortleaf pine is planted at a 10- by 10-foot 

spacing. These stands have numerous hardwood 

sprouts, but planted pines exhibit high survival and 

most are free to grow. At lower elevations, loblolly 

pine is planted. Even though these stands also 

have numerous hardwood sprouts, these sprouts 

are overtopped by the fast-growing pines within a 

few years. On these sites, a wider planting spacing 

or other refinements to the fell-and-burn technique 

may be necessary to allow hardwoods to compete 

with the pines. 

The Southeastern Forest Experiment Station is 

studying several aspects of the fell-and-burn technique and pine-hardwood management. Research 

topics include application of the technique to Piedmont sites, site selection, growth and yield, and 

predicting fire effects. Many important questions 

remain. Once a pine-hardwood stand is established, for example, are intermediate treatments 

such as thinning or release needed? If so, how will 

growth and yield be affected? What products can 

be expected at various stocking levels and rotations? Can uneven-aged management techniques 

be used to establish pine-hardwood mixtures? How 

does the culturing of pines and hardwoods together 

affect wildlife habitat, water qua1 ity, and forest 

protection? As the fell-and-burn technique is 

refined and applied in new regions, it should prove 

useful in establishing pine-hardwood mixtures. 

LITERATURE CITED 

Abercrombie, James A., Jr.; Sims, Daniel M. 1986. 

Fell and burn for low-cost site preparation, 

Forest Farmer 46(1): 14-1 7. 

Augspurger, M.K.; Van bear, B.H.; Cox, S.K.; Phillips, f). R. 1987. Regeneration of hardwood 

coppice following cfearcuning with and without 

prescribed fire. pp. 89-92. In: Phillips, Douglas R., 

ed, Proceedings, 4th biennial southern siiviculiurai research conference. 1986 November 4-6; 

Atlanta, GA. Gen. Tech. Rep. SE-42. Asheville, 

NC: U.S. Department of Agriculture, Farest Service, Southeastern Forest Experiment Station. 

598 pp. 

Bechtold, William A.; Ruark, Gregory A. 1988. Structure of pine stands in the Southeast. Res. Pap. 

SE-274. Ashaville, NC: U .S. Depaflment of Agriculture, Forest Sewice, Southeastern Forest 

Experiment Station. 185 pp. 

Belcher, David M. 1982. TWIGS: The woodsman's 

ideal growth projection system, In: Proceedings 

of a conference sponsored by Purdue University 

Department of Forestry and Natural Resources 

and the Society of American Foresters Systems 

Analysis Working Group and Inventory Working 

Group. 1982 May 4 8-20; West kafayette IN: Purdue University. 

Burkhafl, Harold E.; Sprintz, Peter 9". 1984. A model 

for assessing hardwood competition effects on 

yields of lobfolly pine plantations. Pub!. No. FWS3-84. Blacksburg, VA: Virginia Polytechnic 

Institute and State University, School of Forestry 

and Wildlife Resources. 55 pp. 

Danielovich, Steven J. 1986, High intensity site 

preparation burning after elearcuRing in southern 

hardwoods--effects on residual vegetation and 

soil erosion. Glemson, SC: Cfemson University. 

67 pp. Thesis. 

Danielovich, S. J. ; Van Lear, D.H.; Cox, S.K.; 

Augspurger, M.K. 1987. Burning in Southern Appalachian logging slash--effects on residual 

vegetation and regrovvth. pp. 91 -98. In: Way, 

Ronald L.; Woods, Frank W.; BeSelm, Hal, eds. 

Proceedings of the central hardwood forest conference Wi. 1987 February 24-26; Knoxville, TN. 

Geisinger, Donn R.; Waldrap, Thomas 8.; 

Haymond, Jacqueline L.; Van Lear, David H. 

1989. Sprout growrth FoIIowing winter and spring 

felling with and without summer broadcast burning. [These Proceedings.]. 

Harrison, Wade C.; Burk, Thomas E.; Beck, Donald 

E. 1986. individual tree basal area increment 

and total height equations for Appalachian mixed 

hardwoods after thinning. Southern Journal of 

Applied Forestry 18(2):99-4 04. 
Hilt, Donald E. 1985. OAKSIM: an individual tree 

growth and yield simulator for managed evenaged, upland oak stands. Res. Pap. NE-562. 

Broomall, PA: U.S. Department of Agriculture, 

Forest Service, Northeastern Forest Experiment 

Station. 21 pp. 

Jones, Steven M. 1989. Application of landscape 

ecosystem ctassification in identifying productive 

potential of pine-hardwood stands. [These 

Proceedings.] 

Jones, Steven M.; Van Lear, David H.; Cox, Silas K. 

1984. A vegetat ion-landform classification of 

forest sites within the upper Coastal Plain of 

South Carolina. Bulletin of the Torrey Botanical 

Club 1 1 1 (3) :349-360. 

Lloyd, F. Thomas. 1989. A method for linking standlevel and individual-tree-based growth simulators 

for mixed-species stands. [These Proceedings.]. 

Marquis, David A.; Ernst, Richard L.; Stout, Susan 

L. 1984. Prescribing silvicultural treatments in 

hardwood stands of the Alleghanies. Gen. Tech. 

Rep. NE-96. Broomall, PA: U.S. Department of 

Agriculture, Forest Setvice, Northeastern Forest 

Experiment Station. 90 pp. 

McMinn, James W. 1986. Transpirational drying of 

red oaks, sweetgum, and yeilow-poplar in the 

Upper Piedmont of Georgia. Forest Products 

Journal 36(3):25-27. 

Meldahl, Ralph S.; Bolton, Roger K.; Eriksson, 

Marian. 1988. Development of a mixed species 

projection system for southern forests. pp. 102- 

109. In: Ek, Alan R.; Shifley, Stephen R.; Burk, 

Thomas E., eds. Forest growth modelling and 

prediction, Proceedings, IUFRO conference; 1987 

August 23-27; Minneapolis, MN. Gen. Tech. Rep. 

NC-120. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Forest 

Experiment Station. Vol 1 : 1 -579. 

Phillips, Douglas R.; Abercrombie, James A., Jr. 

1 987. Pine-hardwood mixtures-a new concept in 

regeneration. Southern Journal of Applied 

Forestry 1 1 (4): 192-1 97. 

Sanders, Bradford M.; Van Lear, David H. 1988. 

Photos for estimating residue loadings before 

and after burning in Southern Appalachian mixed 

pine-hardwood clearcuts. Gen. Tech. Rep. SE49. Ashevilie, NC: U.S. Department of Agriculture, 

Forest Service, Southeastern Forest Experiment 

Station. 21 pp. 

Smith, W.D.; Hafley, W.L. 1987. Simulating the effect of hardwood encroachment on loblolly pine 

plantations. pp. 180-1 86. In: Phillips, Douglas R., 

ed. Proceedings, 4th biennial southern silviculturat research conference. 1986 November 4-6; 

Atlanta, GA. Gen. Tech. Rep. SE-42. Asheville, 

NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station. 

598 pp. 

Tennessee Valley Authority. 1988. A user manual 

for INFORM integrated forest management system. Norris, TN: Office of Natural Resources and 

Economic Development, Division of Land and 

Economic Resources. 1 13 pp. 

Van Lear; D.H. 1989. Fell and burn to regenerate 

mixed pine-hardwood stands: an overview of effects on soil. [These Proceedings]. 

Van Lear, D.H.; Danielovich, S.J. 1988. Soil movement after broadcast burning in the Southern 

Appalachians. Southern Journal of Applied 

Forestry 1 2(1):49-53. 

Van Lear, David H.; Waldrop, Thomas A. 1988. Effects of fire on natural regeneration in the 

Appalachian mountains. pp. 52-70. In: Smith, H. 

Clay; Perkey, Arlyn W.; Kidd, William E., Jr., eds; 

Workshop proceedings, guidelines for regenerating Appalachian hardwood stands. 1988 May 

24-26; Morgantown, WV. [Available from 

Southeastern Forest Experiment Station, 

Asheville, NC] 

Waldrop, T.A.; Buckner, E.R.; Shugart, H.H., Jr.; 

McGee, C.E. 1986. FORCAT: A single tree model 

of stand development following clearcutting of 

forests on the Cumberland Plateau. Forest 

Science 32(2):297-317. 
FELL AND BURN TO REGENERATE MIXED 

PINE-HARDWOOD STANDS: AN OVERVIEW OF EFFECTS 

ON SOIL 

David H. Van Lear and Peter R. ~a~eluck' 

.-Effects of the fell-and-burn technique on the soil depend on many variables, When a 

substantial quantity of forest iioor and root mat femain after burning, soil erosion will be minimal. 

Burns which expose large areas of mineral soil in steep terrain are likely to cause excessive erosion, 

Excessive nitrogen volatilization and forest floor losses can be prevented by burning under proper 

fuel and soil moisture conditions. Research conducted over a range of physiographic regions and 

sites is needed to evaluate the appropriateness of this regeneration method. 

INTRODUCTION 

Foresters have long been concerned with fire effects on soil (Arend 1941, Keetch 1944, Wells and 

others 1979). Much concern developed from observations of erosion following fires in steep terrain. In 

addition, questions regarding effects of burning on 

site nutrient status and long-term productivity have 

increased as forest management practices have intensified. Increasing use of broadcast burning to 

prepare sites for conversion of low-quality stands to 

mixed pine-hardwood stands in the Southern Appalachians (Abercrombie and Sims 1986) has 

heightened interest in effects of fire on the soil. 

Reaction to fire and its immediate after-effects is 

often emotional, especially in today's society. The 

charred appearance of burned landscapes presents 

the image of devastation and destruction to the 

general public. Foresters realize, however, that 

most Southern forest ecosystems evolved under 

regimes of frequent or periodic fire (Komarek 1974, 

Van Lear and Waldrop 1989), and that fire has been 

the predominant agent of forest regeneration in the 

South over the millennia. Southern forest ecosystems are generally resilient to fire perturbations, 

and effects on soil are usually, but not always, 

minor. 

The objective of this paper is to present an overview 

of the effects of fell-and-burn regeneration on soil 

erosion and 'nutrient loss. Because the method is 

relatively new, this discussion is based on limited information. Hopefully, this discussion will stimulate 

further research regarding effects of the fell-andburn method on soil. 

TYPES OF PRESCRIBED FlRE AND THEIR 

RELATION TO FIRE INTENSlfY AND SEVERITY 

Prescribed fires are generally classified as being 

one of three types: head, backing, and flanking 

fires (Brown and Davis 1973). Head fires are of relaProfessor and Research Forester, Department 

of Forestry, Clemson University, Clemson, SC. 

tively high intensity and move with the wind or 

upslope at relatively rapid rates of speed. The intensity of a fire is defined as the rate of heat release 

per unit of ground surface area. 

Backing fires move at slower rates of speed and 

burn into the wind or downslope. They are of lower 

intensity than head fires and more easily controlled. 

However, slower burning rates require more time, 

making backing fires more expensive. 

Flanking fires are set parallel to wind direction with 

ignition moving into the wind. They are seldom 

used to burn entire areas, but often supplement 

other burning techniques. 

Fire intensity per se may or may not be closely related to soil response to burning. This apparent 

anomaly is because other factors, such as fuel 

characteristics, soil moisture, and residence time 

can greatly modify effects of fire intensity on the 

soil. For example, a high intensity fire moving rapidly (short residence time) through well-aerated isgging debris when soil and lower forest floor layers 

are moist will generally have little impact on soil 

properties. Only the upper part of the forest floor 

will be consumed. Conversely, a backing fire burning slowly in light fuels during droughty conditions, 

may consume all surface organic matter exposing 

mineral soil and resulting in serious erosion in steep 

terrain. 

The most important factor affecting soil response to 

burning is fire severity, i.e., the condition of the 

ground surface after burning (Wells and others 

1979). Severe burns consume all organic matter on 

the soil surface and alter mineral soil structure and 

color. Moderate burns char the litter and duff, but 

do not visibly change the properties of the mineral 

soil. Light burns only scorch forest floor layers, leaving considerable residual organic material over 

mineral soil. In addition, the depth of the organic 

layers above mineral soil must be considered prior 
to burning. Burns of similar intensity and residence 

time will be more severe on sites where the organic 

layer was thin before burning. 

EFFECTS OF THE FELL-AND-BURN 

TECHNIQUE ON SOIL 

A detailed description of the fell-and-burn method is 

presented in other papers in these proceedings. 

Briefly, residual stems after clearcutting are felted in 

spring when trees have leafed out and allowed to 

cure 6-8 weeks. Felling is followed by a moderateto high-intensity broadcast burn shortly after a soaking summer rain. The goal is to reduce logging 

debris and hardwood competition, yet leave a significant portion of the forest floor and most of the 

root mat to protect the soil from erosion. After the 

summer burn, the area is planted to pine the following winter. High survival rates of planted pine, plus 

development of better quality hardwood coppice, 

produces a mixed pine-hardwood stand. 

This technique has been used to regenerate dozens 

of sites previously occupied by low quality 

hardwood and pine-hardwood stands to good 

quality pine-hardwood stands in the Southern Appalachians (Abercrombie and Sims 1986). The technique is now being tested in the Piedmont. 

We consider the regeneration process to be independent of the harvest operation, which generally 

disturbs 20 to 40 percent of the area in conventional skidder logging (Hatchell and others 1971, Nutter 

and Douglas 1978). Elements of the technique that 

have immediate effects on soil consist of two basic 

components, i.e., manual felling of residual trees 

and broadcast burning of logging slash. The 

former has no detrimental effect on the soil as no 

heavy machinery is used and no organic matter is 

removed from the site. Burning with relatively high 

intensity fires is the component of concern. 

Although the fell and burn components are 

separated in time, they are not independent of each 

other. Without the flashy fuels created by the felling, it would not be possible to conduct the burn as 

quickly following a soaking rain. Under most conditions, the longer a burn is delayed the greater will 

be the consumption of the forest floor, which results 

in greater erosion and nutrient loss from the site. 

Soil and Nutrient Loss by Frosion Following_ir 

Broadcast Burn of Low Severitv 

The effects of broadcast burning on soil erosion 

and nutrient loss are related to the severity of the 

burn. Following a low-severity burn on an Evard 

soil in the Southern Appalachians, Van Lear and 

Danielovich (1988) found that soil movement was 

not increased significantly on slopes ranging from 

21 to 43 percent (table 1 ). Erosion did not increase 

for several reasons, most important of which was 

the fact that mineral soil was exposed on only 15 

percent of the burned area. Sufficient residual 

forest floor and a thick mat of fine and medium 

roots remained to protect the surface of the mineral 

soil. Thus, burn severity was light, even though fire 

intensity was moderate to high, i.e., flame heights 

over most of the area averaged between 5 and 13 ft. 

Most of this area was fired with strip head fires, so 

residence time was shot";. hliach sf the 0.71 tiac sf 

soil trapped behind these sediment dams, which 

were on upper slopes, would not have reached the 

drainage channel; most would have settled out on 

the more gentle grades of lower slopes. 

Losses of available phosphorus and exchangeable 

cations (0.02 to 1.02 I bslaclyr) on eroded sediments from burned plots were too low to cause concern about possible adverse effects on site 

productivity (table 1 ). The pH of sediments was increased by about one-half unit because of increased exchangeable bases in ash from the 

consumed forest floor. The pH of the mineral soil 

was not measured in this study, but other studies 

have reported slash burning raised soil pH by as 

much as 1 to 2 units (Tarant 1956, lssaac and 

Table 1.--Soil and nutrient loss by erosion in the year following 

a broadcast burn of low severity in the Southern Appalachian 

mountains (adapted from Van Lear and Danielovich 1988). 

Treatment Trapped PH Available Exchangeable 

sediment P K Mg Ca 

tlaclyr ------------ lbs/ac---------- 

Control-no 

burn 0+59 4.7 0.01 0.04 0.03 0.31 

Fell and 

burn 0.71 5 3 0.02 0.05 0.05 1.02 
Hopkins 1937). Increased nutrient availability at 

higher pHs may account for frequently reported 

positive plant response following fire (Wells and 

others 1979). However, some investigators attribute 

these responses, at least in part, to a soil sterilization effect (Raison and others 1985). 

Regrowth was rapid on the clearcut area, Shrub 

and herbaceous biomass on burned plots was almost twice that on unburned plots by the end of the 

first growing season after planting. Winter dieback 

of herbaceous vegetation, much of which was annuals, provided a protective mulch over the residual 

forest floor. Slash weights were reduced from 30 to 

38 percent by burning, but 11 to 14 tlac remained. 

In rare instances, large pieces of logging debris 

sewed as sediment dams. lnfiltration rates 

remained high on burned plots, averaging 67 in/hr. 

Infiltration rates of this magnitude far exceed maximum rainfall rates, indicating that overland flow is 

minimal on burned sites where significant quantities 

of residual forest floor remain and the root mat has 

not been significantly reduced. If overland flow is 

minimal, erosion will be minimal. 

All these factors collectively minimize erosion after 

broadcast burns of light severity. Results of this 

study indicate that broadcast burning can be conducted in relatively steep terrain of the Southern 

Appalachians with little increased erosion. However, 

if burning is conducted under inappropriate fuel 

and soil moisture conditions, or if improper firing 

techniques are used, erosion may be dramatically 

accelerated. 

Broadcast Burn of Hiah Severity 

In contrast to the favorable results found in the 

preceeding study, large soil losses were measured 

on a small watershed (0.87 ac) within a fell and 

burned area in the Georgia Piedmont. The harvested area was burned in July of 1988, 4 days after 

a 1.5 in rain. Observations soon after burning indicated that there was little to no residual forest floor 

or root mat left on much of this watershed. Prior to 

burning, this Piedmont site did not have the thick 

duff layer (which includes the root mat) characteristic of sites on the Sumter National Forest in the 

Southern Appalachians. Mineral soil was exposed 

on more than 50 percent of the area and close inspection indicated it would just be a matter of time 

before mineral soil would be exposed on the entire 

watershed and erosion would accelerate. That time 

came during the last week in July when the area 

received a storm that delivered over 4.3 in of rain in 

one day. 

Erosion was estimated from a systematic sampling 

of pedestaled rocks at 50 locations throughout the 

watershed and bulk density of trapped sediments 

collected at the outlet of the watershed. Bulk density of eroded sediments from this Evard sail 

averaged 1.0. During the first 9 months after burning, about 156 t!ac of soil was lost, primarily by 

sheet erosion. Projected to a yearly basis, erosron 

would amount to 207 t/ac (table 2). Sheet erosion 

refers to soil movement resulting from raindrop 

splash and surface runoff (Beasley 1972). Pedestaled rocks, which are indicative of sheet erosion, 

averaged about 1.4 in above the eroded surface 

and were scattered rather uniformly ahroughgut the 

watershed. 

DeBano and others (1 971) found that a water repellent layer developed in soils when brushy areas 

were burned in California. This sub-surface layer 

contributes to increased erosion because the wettable layer above it becomes saturated and results 

in overland flow. It is not known if Typic Hapludult 

soils in the Piedmont develop a hydrophobic layer 

below the soil surface during burning. Infiltration 

rates were not adversely affected in the mountains 

by broadcast burning (Van Lear and Danielovich 

1988), suggesting that these water-repellent layers 

did not form. However, infiltration rates were not 

measured on the Piedmont site and erosion rates 

were high. 

A major gully network developed on this watershed 

soon after burning. Although the area in gullies was 

less than 1 percent of the total area, some gullies 

had cut through the surface horizons to a depth of 

10 in or greater, and were transporting large 

volumes of soil. Greatest soif loss in gullies occurred in the first 4 months after burning (figure 1). 

Depth of gullies did not increase markedly once the 

incised channel reached the underlying clay subsoil. However, their width continued to increase 

throughout the winter due to accelerated erosion associated with freezing and thawing of the exposed 

gully banks. In addition, gully banks continually 

slumped as their sides were undercut by water flowing down the channels. 

Although the low-severity burn discussed earlier increased the rate of secondary succession, regrowh 

on this severely burned watershed was markedly 

delayed. Apparently, seed stored in the lower 

layers of the forest floor were destroyed by burning 

and freshly deposited seed were washed away by 

overland flow. Because of the slow rate of revegetation, these gullies will continue to cut headward and 

expand in width for years. Only after crown closure 

and litter provide surface protection and root 

development binds soil particles together will these 

gullies stabilize. 

If one assumes that nutrient concentrations on sediments deposited on the Piedmont site were similar 

to those on sediments sampled after burning in the 

mountains, then losses of PI K, Mg, and Ca are 3.9, 
Table 2.--Conditions at time of burning and subsequent erosion on 

sites in the Southern Appalachians and Piedmont. 

Site Conditions Erosion 

1. slope=21-43 pct 

2. woody slash=18-22 t/ac 

Southern 3. fuel moisture sticks=IO pet 

Appalachians 4. date of burn=8/24/1984 

5. weather: R~=47 pct 

Air ternp=83 F 

Wind=N3mph 

Piedmont 

1. slope=23 pct 

2. woody slash=13 t/ac 

3. fuel moisture sticks=9 pct 

4. date of burn=7/8/1988 

5. weather: RH=42 pct 

Air temp=83 F 

Wind=S3mph 

LEGEND: 

----- ORIGINAL CON- 

*.**- AFER 4 MONTHS 

-MER 9 MONTHS 

-/ *I \\ LOWER 

- - WID^ (inches) 

Figure I. Transect across a gully 4 and 9 months 

after a broadcast burn in the Georgia Piedmont. 

11.2, 12.1, and 224 lbs/ac, respectively, during the 

9 months after burning. However, since these estimates do not include ash from the consumed 

forest floor, they are considered consewative. 

Why was there such a wide diWerence in soil 

erosion rates following broadcast burning in the two 

situations described above? Fuel loading, fuel moisture stick readings, season of burning, current 

weather conditions, and time since the last rain 

were similar for both sites (table 2). In fact, s/Opes 

were steeper and fuel loading was higher at the 

Southern Appalachian site, yet erosion rates were 

minuscule compared to erosion rates a% the Piedmont site. The explanation of the diMerence must 

lie in two facts. First, even though soif series was 

the same at the two sites, the forest floor and root 

mat was much thicker and better developed @n the 

mountain site than that at the Piedmont site. The 

cooler and moister conditions of the mountains 

would favor the development oh thicker forest floor 

than would be found in the Piedmont. Secondly, 

the 2 months prior to burning the Piedmont site 

were exceedingly dry (a total of onfy 1.6 In of rain 

was recorded for May and June). Because of these 

droughty conditions, the normal moisture gradient 

between the mineral soil and the lower layers sf the 

forest fioor ceased to exist. The relatively heavy 

rainfall (1.5 in) than fell shortly before the Piedmont 

burn apparently only wet the su~ace fiater and did 
not restore moisture contact between the mineral 

soil and forest floor. As a result, the dry forest floor 

was completely consumed, which exposed mineral 

soil and accelerated erosion. Numerous completely 

burned-out stump holes on this watershed attest to 

the dry site conditions at time of burning. 

These two examples of broadcast burning illustrate 

the range of potential effects burning can have on 

sediment and nutrient loss by erosion. In the first 

case effects were minimal, while in the latter, losses 

were extreme. Ballard (1 978) and Glass (1 976) 

have shown that large reductions in pine growth 

can occur on sites where large quantities of soil 

have been displaced by careless windrowing. 

Growth of the new stand would be adversely affected whether the soil was displaced mechanically 

or via erosion. In addition, the deleterious effects of 

sedimentation on productivity of aquatic ecosystems (Miller 1987, Seehorn 1987) must not be overlooked. Sediment in streams reduces invertebrate 

abundance, decreases feeding success of sightfeed ing species, and negatively affects spawning 

success of many fish species. Because of these adverse on- and off-site effects, high rates of erosion 

cannot be tolerated by forest managers. Further research is needed to determine the applicability of 

the fell-and-burn technique under Piedmont conditions, as well as its suitability in other physiographic 

regions. 

This comparison dramatically illustrates the importance of predicting the proper time and conditions 

for conducting broadcast burning to minimize impacts on soil. Fuel moisture sticks are useful as an 

aid in determining when it is possible to burn following a soaking rain (Abercrombie and Sims 1986); 

however, they were not designed to predict potential site damage. What is needed is a model that 

will enable the manager to predict consumption of 

the forest floor and root mat on the surface of the 

mineral soil. Although such models have been 

developed in the Rocky Mountains (Little and others 

1986), we are not aware of similar models for the 

Southeastern United States. Until such models are 

developed, experience and judgement in assessing 

fuel and soil moisture and empirical knowledge 

relating these conditions to fuel consumption 

provide the only means to predict proper conditions 

for burning. 

NUTRIENT LOSSES DURING 

BROADCAST BURNING 

Nitrogen losses from logging debris, because of its 

well-aerated arrangement, can be estimated from 

measured reductions of slash during burning and 

nitrogen concentrations of slash components. 

Sanders and Van Lear (1988) measured fuel loadings before and after broadcast burning in clearcuts 

in the Southern Appalachian mountains. These 

burns were conducted on the Sumter National 

Forest by Jim Abercrombie, the originator of the felland-burn technique. Erosion losses appeared to be 

minimal on these burns as about 45 percent of the 

duff layer (which included the root mat) remained 

after burning (table 3). Woody slash averaged 30 

tiac after harvest and was reduced 52 percent 

during burning. Burning also reduced other fuel 

components, including litter and small live fuels by 

98 and 100 percent, respectively. Within the woody 

slash category, which comprised more than 60 percent of the total fuel, reduction by burning was inversely related to diameter class (figure 2). 

<0.25 1.0-3.0 

0.25- 1.0 >3.0 

fuel size class (in) 

Figure 2. Reduction by burning of four size classes 

of woody fuel (from Sanders and Van Lear 1 987). 

If weight reductions of the various size components 

in figure 2 are multiplied by nitrogen concentrations 

of mixed hardwood logging slash (data available 

upon request from the authors), then 74 I bs/ac of 

nitrogen would be volatilized during consumption of 

logging debris. This calculation assumes that all 

nitrogen in consumed logging debris of various size 

classes is volatilized. Since nitrogen volatilizes at 

relatively low temperatures of about 390" F, this assumption is probably valid. 

Nitrogen losses from the forest floor during burning 

are more difficult to estimate. The largest amount 

of nitrogen reported lost from the forest floor during 

burning was over 714 lbslac in a wildfire in extremely heavy fuels in Washington (Grier 1975). Knight 

(19661, in a laboratory study, estimated that 25 to 

64 percent of the nitrogen content of an old growth 
hemlock-fir forest floor would be volatilized during 

burning, depending on temperature. However, in 

another laboratory study, Morz and others (1 980) 

found no significant difference in the preburn vs. 

postburn nitrogen content of forest floors of three 

forest types after simulated fires. The discrepancy 

in results of these two studies is probably caused 

by different methods of simulating fire. However, 

they indicate the difficulty in estimating nitrogen losses even under controlled conditions. Shock and 

Bin kley (1 986) plotted estimated nitrogen volatilization losses versus forest floor consumption from 

pounds as they are forced downward by heat (DeBano and others 1970) may explain the immediate 

increase in nitrogen content of the lower forest floor. 

Whether this figure over- or under-estimates the actual quantity, it is clear that broadcast burning 

results in substantial losses of nitrogen. Burning 

under conditions of drought when all the forest floor 

is consumed, as well as a much larger proportion of 

the logging slash, could conceivably double 

nitrogen loss. Again, the importance of burning 

under conditions which minimize consumption of 

the forest floor is underscored. 

several southeastern fire studies. They found that 

about 10 Ibs of nitrogen are lost for each ton of or- Based on nitrogen inputs of about 4.5 to 5.5 

ganic matter consumed. If this figure holds for the Ibslaclyr in bulk precipitation to Piedmont and 

Southern Appalachian ecosystems (Van Lear and data in table 3, an estimated 132 lbslac of nitrogen others 1983, Swank and Waide 1988) and the con- would be volatilized from the forest floor during servative nature of nitrogen cycling in southern 

burns of this type. forest ecosystems @Vaide and others 1988, Van 

Estimates of total nitrogen volatilization from consumption of all fuel components in table 3 indicate 

that in excess of 238 lbslac of nitrogen are lost to 

the atmosphere during a typical broadcast burn in 

the Southern Appalachians. However, this estimate 

may be too high. Morz and others (1980) 

measured increases in nitrogen content of the lower 

layer of the forest fl~~r af-ter simulated burning, 

which tended to balance losses from the surface 

layer. Condensation of vaporized organic comLear and others 1989), the nitrogen status of harvested sites should not be adversely affected by infrequent (once per rotation) and properly 

conducted broadcast burns. This input, in conjunction with gains from nitrogen fixation (Boring and 

Swank 1984, Waide and others 1988), probably 

would exceed losses to harvest, burning, and leaching over sawtimber rotations currently recommended for hardwood or pine stands. 

Table 3.--Mean dry weight and reduction by broadcast burning for 

various fuel components in the Southern Appalachian mountains. 

Fuel 

Component 

Weight 

(Tons/ac) 

Reduction 

(Pet) 

Slash 

Preburn 

Pos tburn 

Litter 

Preburn 

Pos tburn 

Duff 

Preburn 

Eaos tburn 

Live 

Prebrrrn 

Pos tburn 

Total 

Preburn 

Pos tburn 
Little is known concerning the fate of nutrients other 

than nitrogen during and after broadcast burning. 

Nutrients contained in ash may be transported off 

the site by wind or water, or retained on site by 

vegetation regrovvth or microbial immobilization. Although the magnitude of these processes has not 

been determined following the fell-and-burn technique, it is safe to say that the former processes will 

dominate on sites where little forest floor remains 

and erosion is great. 

SUMMARY AND CONCLUSIONS 

The fell-and-burn technique of regenerating mixed 

pine-hardwood stands is relatively new. Much research is needed to evaluate the silvicultural effectiveness of the technique and to document its effects on the soil. Currently, there? are only a few 

studies that quantitatively describe effects of the 

technique and the generality of results of these 

studies is not known. 

When prudently conducted by experienced practitioners on the Sumter National Forest in the 

Southern Appalachians in South Carolina, evidence 

(both empirical and experimental) suggests that the 

fell-and-burn technique has little adverse effect on 

the soil. In fact, the combined mulching effect of 

the residual forest floor and die-back of annual herbaceous plants may improve soil water relations for 

the new stand. If a substantial quantity of the 

residual forest floor remains and covers most of the 

burned area, hydrologic functioning of the soil is 

not impaired and erosion is not increased. 

Nitrogen volatilization, even under favorable conditions, is considerable during broadcast burning but 

can be minimized by burning when the soil and 

lower forest floor are moist. The goal of burning with 

this technique should be to reduce logging debris 

to the degree necessary to facilitate planting, yet 

leave as much residual forest floor and root mat as 

possible. Rough calculations indicate that the 

nitrogen status of harvested and burned sites over 

the course of typical savvtimber rotations will not be 

negatively impacted by judicious application of the 

technique. 

The effectiveness and suitability of the fell-and-burn 

technique in the Piedmont and other physiographic 

regions has not been demonstrated. Preliminary 

evidence suggests that Piedmont sites may be 

more sensitive to high intensity fires than mountain 

sites. Because the forest floor and associated root 

mat appears to be thinner in the Piedmont, fires of 

similiar intensity are likely to he more severe in the 

Piedmont than in the Southern Appalachian mountains. 

Broadcast burning under droughty conditions can 

lead to severe erosion and nutrient loss. When normal soil moisture gradients from the forest floor into 

the mineral soil are lacking in dry weather, broadcast burning may consume the entire forest floor 

and associated root mat. Models that predict consumption of forest floor components during burning 

are urgently needed as the fell-and-burn technique 

is increasingly used in steep terrain 

LITERATURE CITED 

Abercrombie, J. A,, Jr.; Sims, D. M. 1986. Fell and 

burn for low-cost site preparation. Forest Farmer 

46: 14-1 7. 

Arend, J. L. 1941. Infiltration as affected by the 

forest floor. Soil Science Society America 

Proceedings. 6:430-435. 

Ballard, R, 1978. EIfects of slash and soil removal 

on the productivity of second rotation radiata 

pine on a pumice soil. New Zealand Journal of 

Forestry Science 8:248-258, 

Beasley, R. P. 1972. Erosion and sediment pollution 

control. The lowa State University Press. Ames, 

lowa. 320 pp. 

Boring, L. R.; Swank, W. 7. 1984. Symbiotic 

nitrogen fixation in regenerating black locust 

) in forest succession. 

Forest Science 30528-537. 

Brown, A. A.; Davis, K. P. 1973. Forest Fire: Control 

and Use. McGraw-Hill Boob Company. New 

York, NY. 686 pp. 

DeBano, L. F.; Rice, R. M. 1971. Fire in vegetation 

management-its effect on soil. p. 327-346. In: Interdisciplinary Aspects of Watershed 

Management Symposium Proceedings, American 

Society of Civil Engineers; Bozeman, MT. 

Glass, G. G. 1976. The effects from rootraking on an 

upland Piedmont loblolly pine site. M.C. State 

School Forest Resource Technical Report. 56 pp. 

Grier, C. C. 1975. Wildfire effects on nutrient distri but ion and leaching in a coniferous ecosystem. 

Canadian Journal of Forest Research 5:599-607. 

Hatchet!, €3. E.; Raiston, C. W.; Foil, R. R. 3970. Soil 

disturbance in logging. Journal of Forestry 

68:772-775. 

Issaac, L. A.; Hopkins, ti. 6. 1937. The forest: soil of 

the Douglas-fir region and the changes wrought 

upon it by logging and slash burning. Ecology 

1 8:264-279. 
Keetch, J. J, 1944. Sprout development on onceburned and repeatedly-burned areas in the 

Southern Appalachians. Tech. Note 59. Asheville, 

NC: U.S. Department of Agriculture, Forest Service, Appalachian Forest Experiment Station. 

3 PP. 

Knight, ti. 1966. Loss of nitrogen from the forest 

floor by burning. Forestry Chronicle 42:149-152. 

Komarek, E. V. 1974. Effects of fire on temperate 

forests and related ecosystems: southeastern 

United States. pp. 251 -272 In: T. T. Kozlowski 

and C. E. Algren (eds) Fire and Fcosystems. 

Academic Press, Inc., New York, 542 pp. 

Little, S. N.; Ottmar, R. D.; Ohmann, J. L. 1986. 

Predicting duff consumption from prescribed 

burns on conifer clearcuts in western Oregon and 

western Washington. Res. Pap. PNW-362. 

Portland, OR: U.S. Department of Agriculture, 

Forest Service, Pacific Northwest Research Station. 29 pp. 

Miller, E. 1987. Effects of forest practices on relationships between riparian area and aquatic 

ecosystems. pp. 40-47. In: Dickson, J. G. and 

Maughan, 0. E. (eds.j Managing Southern 

Forests for Wildlife and Fish Proc.; Gen. Tech. 

Rep. SO-65. 

Mroz, G. D.; Jurgensen, M. F.; Harvey, A. E.; Larsen, M. J. 1980. Effects of fire on nitrogen in 

forest floor horizons. Soil Sci. Soc. Am. J. 44:395- 

400. 

Nutter, W. L.; Douglass, J. E. 1978. Consequences 

of harvesting and site preparation in the Piedmont. p. 65-72. In: T. Tippin (ed) Proc. Symp. 

Principles of Maintaining Productivity on 

Prepared Sites. U .S. Department of Agriculture, 

Forest Service. State and Private Forestry, Atlanta, GA. Orleans, LA. U.S. Department of 

Agriculture, Forest Setvice, Southern Forest Experiment Station. 

Raison, R. J.; Khanna, P. K.; Woods, P. V. 1985. 

Mechanisms of element transfer to the atmosphere during vegetation fires. Canadian Journal 

Forest Research 15:132-140. 

Sanders, B. M.; Van Lear, D. H. 1987. Pre- and postburn photo series for pine-hardwood logging 

slash in the Southern Appalachians. p. 41 -48. In: 

Ninth Conference on Fire and Forest Meteorology. April 21-24, 1987. San Diego, CA. American 

Meteorological Society, Boston, MA. 

Schock, P.; Binkley, D. 1986. Prescribed burning increases nitrogen availability in a mat ure lobloll y 

pine stand. Forest Ecology and Management 

14: 13-22. 

Seehorn, M. E. 1987. The influence of silvicultural 

practices on fisheries management: effects and 

mitigation measures. p. 54-63. In: Dickson, J. G.; 

Maughan, 0. E. (eds.) Managing Southern 

Forests for Wildlife and Fish Proc.; Gen. Tech. 

Rep. SO-65. New Orleans, LA. U.S. Department 

of Agriculture, Forest Service, Southern Forest Experiment Station. 

Swank, W. T.; Waide, J. B. 1988. Characterization 

of baseline precipitation and stream chemistry 

and nutrient budgets for control watersheds. p. 

57-79. In: Swank, W. T. and Crossley, D. A., Jr. 

(eds.) Forest Hydrology and Ecology at Coweeta. 

Springer-Verlag, New York. 469 pp. 

Tarrant, R. F. 1956. Effects of slash burning on 

some soils of the Douglas-fir region. Soil Science 

Society of Amercia Proceedings. 20:408-411. 

Van Lear, D. H.; Waldrop, T. A. 1989. History, uses, 

and effects of fire in the Southern Appalachians. 

Gen. Tech. Rep. SE-54. Asheville, NC: U.S. Dept. 

of Agriculture, Forest Service, Southeastern 

Forest Experiment Station. 

Van Lear, D. H.; Danieiovich, S. J. 1988. Soil movement after broadcast burning in the Southern 

Appalachians. Southern Journal Applied Forestry 

1 2: 49-53. 

Van Lear, D. H.; Kapeluck, P. R.; Waide, J. 8. 1989. 

Nitrogen pools and processes during natural 

regeneration of loblolly pine. In: Sustained 

Productivity of Forest Land. 7th North American 

Forest Soils Conf. July 24-28, 1988. Vancouver, 

B.C. (In press). 

Waide, J. B.; Caskey, W. H.; Todd, R. L.; Boring, L. 

R. 1988. Changes in soil nitrogen pools and 

transformations following forest clearcutting. p. 

231 -232. In: Swank, W. T. and Crossley, D. A., Jr. 

(eds.) Forest Hydrology and Ecology at Coweeta. 

Springer-Verlag, New York. 469 pp. 

Wells, C. G.; Campbell, R. E.; DeBano, L. F.; and 

others. 1979. Effects of fire on soil: A state-ofknowledge review. Gen. Tech. Rep. WO-7. 

Washington, D.C.: U.S. Dept. of Agriculture, 

Forest Service. 34 pp. 
SPROUT GRO H FOLLOWING WllNTE%$ AND SPRING 

FELLING WITH AND WITHOUT SUMMER BROADCAST 

BURNING 

Donn R. Geisinger, Thomas A. Waldrop, Jacqueline L. Haymond, and 

David H. Van b_earl 

-Young naturally regenerated prns-hardwood stands are oMen characteftzed by vlgoraus 

hardwood sprouts overtopping plne seedltngs For severat years m~xed stands have been 

regenerated successfuiiy In the Southern bpaiachians by planting pines In hardvvooa clearcuts 

Hardwood compet~tion has been controlled by sprtng fell~ng of residual stems and summer broadcast burnlng This study documents the effect of these treatments on frrst-year sprout growh in 

the P~edmont of South Carolina Four treatments were imposed followrng a cammsrctal clearcut 

(I) w~nter fell~ng of residuals, (2) sprlng fell~ng of ras~duals, (3) virlntsr fellrng followed by a summer broadcast burn, and (4) spring felling followed by a summer broadcast burn ' Spr~ng felling 

followed by a summer burn provided the greatest control of height growth and crown spread of 

hardwood sprouts. The effect of burn~ng was more lmpsrtant than season of fell~ng because of 

the reduced time for sprout development. Number of sprouts per clump was generally unanected 

INTRODUCTION 

Approximately 80 percent of the forested land of the 

Southeast Piedmont area is owned by individuals or 

family groups. The tracts are small (average about 

ten acres) and most are cutover lands or old abandoned farms. The existing timber on these scattered lands is, for the most part, of low quality and 

is usually comprised of mixed pine-hardwood or 

hardwood species that are not highly desirable or 

suitable for the production of commercial wood 

products (McMinn 1983). An inexpensive regeneration system to change these low-quality stands to a 

productive state is needed. 

A site preparation technique called fell and burn 

has been used in the Southern Appalachians to effectively and economically establish mixed pinehardwood stands on certain sites (Phillips and 

Abercrombie 1987). The fell-and-burn procedure is 

described in detail elsewhere in these proceedings 

(Mlaldrop and others 1989) and consists of spring 

felling of residual stems (after clearcutting) followed 

by a summer broadcast burn. The objective of this 

study was to determine the effects of season of felling and summer burning on sprout development. 

METHODS 

Study sites are located on the Clemson University 

Experimental Forest. These sites were selected For 

consistency and similarity of aspect, soil, and 

vegetation. Before harvesting in December 1987 

Graduate Research Assistant, Clemson University, 

Department of Forestry, Clemson, SC; Research 

Forester, USDA Forest Service, Southeastern Forest Experiment Station, Clemson, SC; Assistant Professor, 

Clemson University, Deparrment of Forestry, Clemson, 

SC; and Professor, Clemson University, Department of 

Forestry, Glemson, SC. 

and March 9988, major tree species included white 

b.). Slopes averaged 7 to 10 percent on 

all replications. AtO soils were described as Typic 

Hapludults. 

Before haruest, 89 li40th acre plots were established in three repi ications sf four treatments. Treatments included: 

1. winter felling of residuals with na burning, 

2. spring felling of residuals with no burning, 

3. winter felting sf' residuals with summer broadcast 

burning, and 

4. spring felling of residuals with summer braadcast 

burning. 

Spring felling was cornpared eo winter felling to 

determine if sprout gr0Wf9 is reduced by felling 

when carbohydrate resewes are typically low. 

Chainsaw crews felled all residual sterns aver 5 feet 

tall Itha% were present a&er commercial clearcurting. 

Winter Felling was completed in early March 1988; 

spring fedling was conducted in June 1 988. 

Burning took place on July 7, 1988, two days aFter a 

rainfall &sf -f!2 inch, Humidity at the lime of burning 

was 56-68 percent and wind speed was approximately five MPH. Moisture content of 10-hour 

timelag fuels fli2-1 inch in diameter) was 12 percent at 10:60 A.M. and 9 to 10 percent after noon. 
Burning was accomplished with hand crews and 

drip torches. Backing fires were started along the 

edges of the units until a sufficient blackened strip 

was attained. Strip-head fires were used to ignite 

the interior fuels. Fuel loading varied from little or 

none to very heavy, depending upon disturbance 

by skidding and the presence of tree tops. Fuels 

consisted of large logs, old down materials, freshly 

felled residuals, tops, branches, leaf litter and new 

growth. Fuel loading before and after the broadcast burn was determined by the planar intersect 

method (Brown 1971). Sizes, quantities, and 

depths of fuels were measured. 

Burning in spring-felled areas was more complete 

and uniform than in winter felled areas. Loading of 

fine fuels (.5 inch diameter) prior to burning 

averaged 0.4 ton per acre in both winter- and 

spring-felled areas (table 1). After the burn, fine fuel 

loading had been reduced by 75 percent in the 

spring-felled areas but by only 50 percent in the 

winter-felled areas. The depth of all fuels was 

reduced by 77 percent in spring-felled areas and by 

54 percent in winter-felled areas. These differences 

were partially due to the presence of leaves on the 

stems felled during spring. After a tree is cut, the 

transpirational function of leaves continues to 

Data collected at the end of the first growing season 

remove water from the bole and branches (McMinn 

1986). Dry leaves also served as fuels to carry the included: 1) stump height and diameter, 2) number 4i rn 

IllG. of sprouts per stump, 3) height of the dominant 

sprout on each stump and 4) crown diameter of Species composition of regeneration closely 

each sprout clump. resembled that of the pre-harvest stand. Regeneration at the end of the first-year growing season Treatments were compared by analysis of variance (table 2) consisted of scarlet oak, southern red oak, and means separation was by linear contrast. Number of sprouts per stump, height of the dominant 

sprout and diameter of the sprout clump were used 

Table 2.--Species composition of regeneration. 

as indicators of sprout growth. Treatment differen- Species Stems per acre ces were compared with each variable for the common species or species groups including: oak, Shortleaf Pine 57 

hickory, biackgum, other hardwoods and all select oakse 4,290 

species combined. Hickory 1,350 

Blackgum 1,647 

RESULTS AND DISCUSSION 

Broadcast burns were of hig h-intensity with flames 

Other Hardwoods 4 347 

Total 11,691 

reaching heights of 10 to 15 feet where fuel loading a Scarlet oak (Quercus coccinea Muenchh.), 

was heavy. However, fire severity was low with ex- southern red oak (&. falcata Michx.), white oak 

posure of mineral soil on no more than 22 percent (&. alba L. ) , post oak (&. stellata Wangenh.) , 

of the burned areas (table 1). black oak (&. velutina Lam.), chestnut oak 

(&. prinus L.). 

Table 1.--Characteristics of fuels and exposed soils before and after 

burning by season of felling. 

Winter felled Spring felled 

Weight of fine fuels ((0.5 in dia) 

Before burning 

After burning 

Percent reduction 

Depth of all fuels 

Before burning 

After burning 

Percent reduction 

Soil exposure 

Before burning 

After burning 

(tons per ac) 

0.4 0.4 

0.2 0.1 

50 75 
Table 3.--Average number of sprouts per stump by species group and treatment, 

Other All 

Treatment Oak Hickory Blackgum Hardwoods Species 

Winter felllno burn 5.7 a 2.1 a 5.6 a 14.6 a 7.8 a 

Spring fell/no burn 5.1 a 4.7 b 4.6 a 12.4 ab 6.8 a 

Winter felllburn 6.5 a 4.3 b 5.9 a 11.3 ab 7.4 a 

Spring felllburn 4.2 a 4.1 b 4.6 a 10.1 b 7.0 a 

'Means followed by the same letter within a column are not significantly 

different at the 0.05 level. 

white oak, post oak (Q. stellata Wangenh.), black 

oak, chestnut oak, hickories, blackgum, sourwood 

and dogwood. Minor species included black cherry 

(Prunus ~erotina Ehrhart), red maple (Acer rubrum 

L.), yellow-poplar, holly (W ~r>aca Aiton), persimmon (Diospvros viainiana L.) sassafras (Sassafras 

a1 bidum (Nuttall) Nees) and hawthorn (Crataw 

spp.). Primary invader species were present in the 

burned areas, but few or none were found in the uflburned treatments. These invader species included 

vetch (16icia spp,), butterfly pea (Clitoria ' 

L.), fireweed (Erechtites hieracifolia (L.) Raf), and 

pokeweed (Phw americana L.). 

Spring felling and summer burning had little effect 

on the number of sprouts per stump for oaks, blackgum, and all species combined (table 3). For hickory, the winter fell treatment with no burning 

produced significantly fewer sprouts per stump 

than other treatments. In the other hardwoods 

group, the number of sprouts per stump was 

reduced to some degree by spring felling alone and 

by winter felling with burning. The combination of 

spring felling and burning produced the fewest 

sprouts per cut stem. These findings appear to contradict those of Augspurger and others (1 987) and 

Waldrop and others (1 985) who found that the number of sprouts per acre was increased by fire. 

However, this difference may be due to the shorter 

growing period of this study or from the methods 

used to determine sprout numbers (on a per acre 

basis vs. a per stump basis). Since burning 

created open conditions, additional seedlings and 

sprouts may develop during the second growing 

season. 

Summer broadcast burning reduced the height of 

the dominant sprout of most species groups by approximately 50 percent (table 4). Spring felling with 

summer burning reduced height more than did 

winter felling and burning and produced a significant reduction in the growth of blackgum, hickory, and other hardwoods. Spring felling without 

burning had little affect on height growth. These 

results suggest two primary advantages of spring 

felling over winter felling: 1) spring felling provides 

fuels for more uniform and timely burning and 2) 

spring felling contributes to the overall control of 

hardwood sprout growth in the fell-and-burn 

method. Of the two components, burning had 

Table 4. Average height (in) of dominant sprout by species group and treatment. 

Other A11 

Treatment Oak Hickory Blackgum Hardwoods Species 

Winter fell/no burn 39.7 a 18.1a 30.6 a 41.9 a 36.4 a 

Spring fell/no burn 36.2 a 14.7 ab 29.5 a 40.7 a 32.4 b 

Winter felllburn 18.7 b 13.5 b 24.0 a 23.1 b 18.3 c 

Spring felllburn 18.6 b 9.5 c 12.5 b 18.8 c 15.8 c 

'Means followed by the same letter within a column are not significantly 

different at the 0.05 level. 
more effect on growth than spring felling. The 

reduction in height of competing hardwoods on 

burned plots was due to a shorter growing period 

rather than an inhibitive response to burning 

(Danielovich and others 1987). 

The average diameter of the crowns of sprout 

clumps was affected by summer burning and 

spring felling (table 5). Burning significantly 

reduced crown diameters of oak, other hardwoods, 

and all species combined. Without burning, spring 

felling had no effect. However, the combination of 

spring felling and burning produced the smallest 

crown diameters of all treatments. Similar to height 

growth, burning was more critical for controlling 

crown spread than season of felling. However, 

spring felling produced more uniform burning conditions. 

SUMMARY AND CONCLUSIONS 

Spring felling of leafed-out residuals followed by 

summer burning (fell-and- burn site preparation) 

produced the greatest reductions in heights of the 

dominant sprouts and crown diameters of sprout 

clumps. Of the variables measured, number of 

sprouts per stump was least affected by the treatments. Burning reduced average sprout height for 

most species from generally over 3 feet to less than 

1.5 feet. Spring felling with summer burning was 

more effective than winter felling and burning in 

reducing growth of several species groups. Reduction of dominant sprout heights and crown 

diameters should reduce shading of planted pines 

thus allowing the successful establishment of a pinehardwood mixture. Reduced growth of sprouts was 

attributed primarily to a shortened time to develop 

after burning, although sprout vigor may also have 

been affected. 

The oaks appeared to be somewhat less affected by 

spring felling than each sf the other species groups. 

After burning, sprouts of hickory, blackgum, and 

other hardwoods were smaller (height and crown 

diameter) in spring felled areas than in areas where 

felling was conducted in the winter (tables 4 and 5). 

The oaks showed no significant reductions in height 

growth or crown spread due to spring felling. If this 

pattern remains apparent over several growing 

seasons, the combination of spring felling and summer burning may prove beneficial to establishment 

of the more desirable oak species. 

The success of the fell-and-burn technique for establishing pine- hardwood mixtures has been attributed, in part, to controlling hardwood sprout 

growth (Phillips and Abercrombie 1987, Danielovich 

and others 1987). This control was assumed to be 

the effect of carefully timed broadcast burning and 

felling of residuals when carbohydrates are in low 

supply. After a single growing season, this study 

shows that the fell-and-burn technique eNectively 

reduced hardwood growth in the Piedmont of South 

Carolina. The reduced size of hardwood sprouts 

(both height and crown diameter) was primarily due 

to burning. Felling residual stems during the spring 

was less effective in reducing sprout growth than anticipated. Without burning, spring felling had little 

affect on sprout growth. 

Table 5.--Average diameter (in) of clump crown by species group and treatment. 

Other All 

Treatrnen t Oak Hickory Blackgum Hardwoods Species 

Winter fell/no burn 24.0 a' 10.1 ab 24.1 a 33.3 a 24.9 a 

Spring fell/no burn 24.1 a 10,3 a 22,7 a 29.3 a 22.9 a 

Winter fellfburn 18.1 b 11.8a 21,8 a 20.0 b 16,1 b 

Spring felllburn 13.6 b 7.9 b 10,3 b 16,o e 132 c 

'~eans followed by the same letter within a column are not significantly 

different at the O,O5 level. 
LITERATURE CITED 

Augspurger, Mark K.; Van Lear, David H.; Cox, 

Silas K.; Phillips, Douglas R. 1,987. Regeneration 

of hardwood coppice following clearcutting with 

and without prescribed fire. pp. 89-92. In: Phillips. Douglas R., ed, Proceedings, 4th Biennial 

Southern Silvicultural Research Conference. 

1986 November 4-6; Atlanta, GA. Gen. Tech. Rep. 

SE-42. Asheville, NC: U .S. Department of Agriculture, Forest Service, Southeastern Forest 

Experiment Station. 598 pp. 

Brown, J. K. 1971 . A planar intersect method for 

sampling fuel volumes and surface area. Forest 

Science 1 7:96-102. 

Danielovich, S.J.; Van Lear, D.H.; Cox, S.K.; 

Augspurger, M.K. 1987. Burning in Southern Appalachian logging slash--effects on residual 

vegetation and regrowth. pp. 91 -97. In: Hay, Ronlad L.; Woods, Frank W.; DeSelm, Hal, eds. 

Proceedings, Central Hardwood Forest Conference VI. 1987 February 24-26; Knoxville, TN. 

526 pp. 

McMinn, James W. 1983. Pine regeneration following fuel chip utilization of mixed hardwood-pine. 

Georgia Forestry Commission Research Paper 

41. 6 pp. 

McMinn, James W. 1986. Transpirational drying of 

red oaks, sweetgum, and yellow-poplar in the 

Upper Piedmont of Georgia. Forest Products 

Journal 36(3): 25-27. 

Phillips, Douglas R.; Abercrombie, James A. 1987. 

Pine-hardwood mixtures---a new concept in 

regeneration. Southern Journal of Applied 

Forestry 1 1 : 1 92-1 97. 

Waldrop, Thomas A,; Buckner, Edward R.; Muncy, 

Jack A. 1985. Cultural treatments in tow-quality 

hardwood stands for wildlife and timber production. pp. 493-500. In: Shoulders, Eugene, ed. 

Proceedings, 3rd Biennial Southern Silvicultural 

Research Conference. 1984 November 7-8; Atlanta, GA. Gen. Tech. Rep. SO-54. New Orleans, LA: 

U.S. Department of Agriculture, Forest Service, 

Southern Forest Experiment Station. 589 pp. 

Waldrop, T.A.; Lloyd, F.T.; Abercrombie, J.A. 1989. 

Fell and burn to regenerate mixed pine-hardwood 

stands: an overview of research on stand development. [These Proceedings.]. 
INFLUENCE OF WHOLE-TREE HARVESTING ON STAND 

COMPOSITION AND STRUCTURE IN THE OAK-PINE TYPE 

James W. McMinnl 

. -Oak-pine stands in the Upper Piedmont of Georgia were harvested with small fellerbunchers in both the dormant season and early growing season to 1 -inch and 4-inch lower diameter 

limits. After 9 years of natural stand development, both season and intensity of harvesting significantly influenced species composition and stand structure. Areas harvested during the growing season developed into essentially hardwood stands, while dormant-season harvests produced 

a substantial pine component, On the 4-inch-limit areas, competition to regeneration from the 

harvest residuals was still apparent. 

INTRODUCTION 

l ntensive whole-tree hawesting can be a practical 

way to remove poor stands with little timber-producing potential (Butts and Preston 1979). Key questions remain, however, about the species 

composition and stand development of natural 

regeneration that follows intensive harvesting, To 

address these questions, a study was established in 

a mixed hardwood-pine association on the Upper 

Piedmont of Georgia. Study variables were intensity and season of harvest. Treatment effects on 

hardwood sprout coverage and pine regeneration 

through the first five growing seasons after harvesting were presented by McMinn and Nettter (1988). 

This paper presents results based on the entire 

stands nine growing seasons after harvest: it is the 

first time in the study that the same response variables--basal area and number of stems per acre-- 

are applied to the hardwood coppice, pine 

regeneration, and harvest residuals. 

,) in descending order 

ominant conifers were 

I.), Virginia (P &- 

Mill.), and loblolly pine (E L') , 

Table 1,--Mean number of stems and bmal area per acre prior to 

harvest by species group and size class 

Shrub 67.7 

Yellow pine 112.2 47.0 5.4 

Soft hardwood 66.7 2.7 0.3 

Hard hardwood 500.4 51.4 25.9 

Pliscellmeous 141.1 11.7 1.0 

All species 888.1 112.8 32.6 

Basal area ( ftL/acre 

Shrub 0.4 

Yellow pine 6.6 14.6 3.4 

Soft hardwood 0.7 0.8 0.4 

Hard hardwood 14.2 15.7 21.8 

Miscellaneous 6.5 3.1 0.7 

All species 28.4 34.2 26.3 

METHODS 

The study area is on the Dawson Forest, which is 

managed by the Georgia Forestry Commission. 

Prior to management by the Commission, the area 

had been abandoned for agriculture, undergone 

natural succession, and been subjected to high 

grading typical of stands in the region. Soils are 

eroded phases of Fannin fine sandy loam with inclusions of Tallapoosa fine sandy loam. Both soils 

are Ultisols in the Typic Hapludult and Ochreptic 

Hapludult subgroups, respectively. The initial 

hardwood component was comprised primarily of 

Muenchh.), post oak 

"Species are grouped according to standard Forest Survey 

categories. 

One-acre treatment plots were harvested with a typical whole-tree system that included a small felierbuncher and grapple-skidders. Harvesting 

removed all material down to 4-inch or 1 -inch 

diameter limits in both January and June of 1980. 

Each combination of season and intensity was replicated three times in a completely randomized 

design. Detailed observations and measurements 

were confined to the interior 0.5 acre of each 1 -acre 

plot. In November and December of 1988 nine 0.01 - 

acre circular subplots were located systematically 

on each 0.5-acre measurement plot. D. b. h. of all 

stems greater than 0.4 inch d. b. h. on each subplot 

was measured to the nearest 0.1 inch. Basal area 

and number of stems per acre were computed by 

species group and compared among treatments by 

analysis of variance. 

hesearch Forester, USDA Forest Service, 

Southeastern Forest Experiment Station, Athens, GA. 
RESULTS AND DISCUSSION 

The 9-year-old stands originated from a combination of hardwood coppice regeneration, pine seedling regeneration, and in some treatments small 

pine and hardwood harvest residuals (table 2). At 

this stage, the stands have not reached a stable 

number of stems per unit area, but substantial mortality has occurred in pine seedlings and hardwood 

sprouts. To understand the factors affecting the 

species composition and structure of the stands, it 

helps to first focus on pine and hardwood regeneration alone and then the combination of regeneration 

and harvest residuals. 

Table 2.--&an values by stand trait and harvesting treatment 

after nine growing seasons 

Harvesting treatment 

Seeson: Domant Domsnt Growing Growing 

Diameter 

Stand trait limit: 1-inch 4-inch 1-inch 4-inch 

Regeneration only 

Stem per acre Pine 1104 115 42 

Hardwood 5188 1984 1222 2070 1192 

Basal area (sq.ft.per acre) 

Ptne 61.4 13.5 1.2 0.4 

Hardd 16.5 9.8 15.8 8.3 

Residuals and regeneration 

Stems per acre Pine 51a 1141 119 1iXj 

Hard 1984 1637 2070 1619 

Basal (sq.ft.per acr(3) 

Pine 61.4 18.1 1.2 4.9 

Herdwood 16.5 28.4 15.8 22.3 

&generation Alone 

Overall, different harvesting treatments gave rise to 

different stand characteristics, primarily through influences on pine regeneration (table 3). Very large 

effects of harvest season are probably related to the 

presence of viable pine seeds on the ground at the 

time of harvest. In this study, most of these seeds 

came from pines in the harvested stands, and harvesting provided the only site preparation for seeds 

that had already fallen. This regeneration technique 

has been formally characterized as the "seed-inplace" method (Langdon 1981 ). There were few 

pine seedlings in place prior to harvesting. In the 

absence of harvesting disturbance, few seedlings 

become established because the forest floor 

prevents seed contact with mineral soil (Pomeroy 

1949; Yocum and Lawson 1977). Seed predators 

and fungi likely destroy a substantial proportion of 

the seed crop by early summer. Seedlings that do 

become established are vulnerable to destruction 

by the hawesting operation. Timing the harvest 

after an adequate seedfall and before hot weather, 

therefore, is crucial to regeneration success with 

this technique. Adjacent stands were the probable 

seed source for the few pine seedlings on plots harvested in the early growing season. The difference 

in pine seedling occurrence by harvest intensity is 

probably due partly to mechanical disturbance and 

partly to competition by residual woody vegetation. 

Significantly more mineral soil was exposed by the 

more intense harvesting. 

Table 3.--Smary of analysis of variance results for 

naturally regenerated oak-pine stands nine growing seasons 

after harvesting 

Source of variation 

Stand trait Season Liai t Season x limit 

Regeneration Only 

Pine stem count 

Hardwood stem count 

Pine basal area 

Hardwood basal area 

Pine stem count 

Hardwood stem count 

Pine basal area 

Hardwood basal area 

Residuals and regeneration 

%* = significant at the 0,01 alpha level, = significant 

at the 0.05 alpha level, NS = nonsignificant. 

At age 9 there was no significant difference in number of hardwood coppice stems or basal area by 

treatment. However, hardwood coppice crown 

coverage had been significantly greater at age 2 

after dormant season harvests and with a 1 -inch 

limit. At age 4 and 5 coppice coverage was significantly greater on the 1 -inch areas and exhibited 

evidence of competition from pine seedlings established after dormant season harvests (McMinn and 

Nutter 1 988). Although statistically nonsignificant, 

some effect of diameter limit was apparent in 

hardwood regeneration at 9 years. The 1 -inch limit 

produced an average of 68 percent more stems 

with 79 percent greater basal area than the 4-inchlimit harvests. This difference is attributed primarily 

to competition from the harvest residuals. A negligible proportion of hardwood sprouts originated 

from trees less than 4 inches d. b. h. A high proportion of the smaller stumps were destroyed to below 

the groundline by the tracked feller-buncher, and all 

sprouting was associated with identifiable stumps. 

The net effect of treatments after 9 years was a drastic difference in the relative predominance of pine 

and hardwood. Dormant season harvest resulted in 

stands with a large pine component, but there was 

a substantial difference between harvest limits 

within the dormant season treatment. Pine basal 

area on the 1 -inch-limit plots was over 3.5 times the 

hardwood basal area, On the 4-inch limit plots, 

pine basal area was less than 1.5 times the 

hardwood basal area. In sharp contrast to the dormant-season treatments, the growing season treatments exhibited less than 10 percent as much pine 

as hardwood basal area. 
After the 1 -inch-limit harvests, regeneration comprised essentialiy the entire stands. After the growing-season 4-inch-limit treatment, a relatively 

modest number of residual stems translated into a 

substantially larger basal area at age 9: the majority 

of this basal area was hardwood. This effect was 

even more pronounced after the dormant-season 4- 

inch-limit treatment. Among regeneration, 58 percent of the basal area was pine. However, with 

residuals added, pine basal area comprised 39 percent of the stand. 

The differences in total stand characteristics by 

treatment are most evident in diameter class distributions of stems and basal area by species group 

(tables 4 and 5). In the dormant-season 1 -inch-limit 

treatment, 68 percent of the total stems and 59 percent of the total stand basal area was 1 - and 2-inch 

pines. The greatest number of stems is in the pine 

1-inch diameter class and the greatest basal area is 

in the pine 2-inch diameter class. By contrast, in 

the dormant-season 4-inch-limit treatment the 

largest number of stems is in the hardwood 1-inch 

diameter class and the greatest basal area in the 

hardwood 4-inch diameter class. The most skewed 

distribution of both stems and basal area occurred 

in the growing-season 1 -inch-limit treatment: 

hardwoods in the 1- and 2-inch diameter classes accounted for 93.6 percent of the stems and 87.6 percent of the basal area. The growing-season 

4-inch-limit treatment produced the most even distribution of basal area across diameter classes, but 

the majority of the basal area was from residual 

stems. 

Table 4. --Diameter class distributions by species group and 

treatment after nine growing seasons 

D.b.h. class (inches) 

Species group 1 2 3 4 5 6 

-------- -Stems (pet)- - - - - - - - 

Dormant season, 1-inch limit 

Pine 46.8 20.9 3.9 0.7 0.1 0.0 

Hardwood 22.0 4.4 1.2 0.1 0.0 0.0 

Dormant season, 4-inch limit 

Pine 25.2 11.9 2.5 0.9 0.3 0.3 

Hardwood 40.5 9.6 3.7 4.0 0.9 0.1 

Growing season, 1-inch limit 

Pine 3.7 1.4 0.3 0.0 0.0 0.0 

~ardwood 75.5 18.1 1.0 0.0 0.0 0.0 

Growing season, 4-inch limit 

Pine 2.2 1.6 0.7 0.5 0.2 0.7 

Hardwood 68.0 16.7 4.7 2.9 1.6 0.2 

Table 5.--Total stand basal area distribution by species 

group and diameter class after nine growing seasons for four 

harvesting treatments 

D.b.h. class (inches) 

Species group 1 2 3 4 5 6 

------- Basal area (pet) - - - - - - - 

Dormant season, 1-inch limit 

Pine 22.6 36.0 14.7 4.9 0.5 0.0 

Hardwood 7.9 7.6 5.0 0.8 0.0 0.0 

Domant season, 4-inch limit 

Pine 7.7 13.7 6.4 4.9 2.4 3.6 

Hardwood 10.1 11.6 10.5 20.0 7.7 1.3 

Growing season, 1-inch lilnit 

Pine 1.8 3.5 1.8 0.0 0.0 0.0 

Hardwood 42.9 44.7 5.3 0.0 0.0 0.0 

Growing Season, 4-inch limit 

Pine 0.7 2.6 2.2 2.2 1.8 8.1 

Hardwood 17.7 19.6 13.7 15.9 12.5 3.0 

CONCLUSIONS 

Both season and intensity of whde-tree hawesting 

significantly influenced species composition and 

stand structure after 9 years of natural stand 

development. Areas harvested during the growing 

season developed into essentially hardwood 

stands, while dormant-season harvests produced a 

substantial pine component. On the 4-inch-limit 

areas competition of residuals with pine seedlings 

and hardwood coppice was apparent. 

The results have some clear silvicultural implications for forest types similar to the one studied here. 

The intensity and timing of harvests can be expected to strongly influence the species composition and structure of naturally regenerated stands. 

To maximize the pine component of such stands, 

harvesting should be done during the dormant 

season with adequate numbers of seeds in place. 

Harvests during the growing season will produce almost pure stands of mixed hardwoods. Standing 

harvest residuals will influence the character of the 

stand indefinitely, so possible long-term silvicultural 

benefits should be weighed against the expense of 

removing all standing material. The treatments with 

only minor modifications appear to be good options 

for low-cost management. 

ACKNOWLEDGEMENT 

Appreciation is expressed to the Georgia Forestry 

Commission for substantial support and cooperation in this study. 
LITERATURE CITED 

Butts, Paul M.; Preston, Druid N. 1979. Whole tree 

chipping: a forest management tool. Ga, For. 

Res. Pap. 4. Macon, GA: Georgia Forestry Commission; 8 pp. 

Langdon, O.G. 1981 . Natural regeneration of lobtolly pine: a sound strategy For many forest 

landowners. Southern Journal of Applied Forestry 

5: 170-1 76. 

McMinn, James W. 1987. Coppice regeneration in 

the oak-pine type relative to initial species composition, stand structure, and season of felling. 

pp. 166-168. In: Phillips, Douglas R., comp. 

Proceedings of the 4t h Biennial Ssut hern Silvicultural Research Conference; 1 986 November 4-6; 

Atlanta, GA: Gen. Tech. Rep. SE-42. Asheville, 

NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station. 

McMinn, James W. and Nutter, Wade L. 1988. 

Season and intensity of whole-tree harvesting influence regeneration in the oak-pine type. 

Canadian Journal of Forest Research 18:669-674. 

Pomeroy, K.B. 1949. The germination and initial establishment of loblolly pine under various surface 

soii conditions. Journal of Forestry 472541 -543. 

Yocum, H.A.; Lawson, E.R. 1977. Tree percent from 

naturally regenerated shortleaf pine. Southern 

Journai of Applied Forestry 1 : 10-1 1. 
THE DEVELOPMENT OF FIVE-YEAR-OLD MIXED UPLAND 

HARDWOOBPINE STANDS 

S.M. Zedaker, D.Wm. Smith, R.E. Kreh, and T.S. ~redericksen' 

Abstract. -The effects of harvest season and four regeneration treatments on natural hardwood 

and planted loblolly pine density and height were evaluated five years after clear felling on the 

upper Piedmont of Virginia. Low-input cultural treatments resulted in a full range of stand conditionsfrom almost pure pine to mixed hardwood-pine to pure hardwood stands, Hardwood species 

composition after clear felling differs dramatically from pre-harvest conditions in that shade intolerant to intermediate species are being replaced with more tolerant associates. 

INTRODUCTION 

Low-input forest stand regeneration alternatives are 

attractive to many forest landowners who do not 

have the resources, or do not desire to use capitalintensive forest management systems. Landowners 

need management information for low-cost 

regeneration of forest stands to meet product objectives that could be obtained from mixed hardwood, 

hardwood-pine mixtures, and pure pine stands. 

Considering the costs of establishing and maintaining pine plantations, the abundance of hardwood 

stems in the Piedmont, and the uncertainty of future 

market conditions, some researchers have advocated the use of pine-hardwood mixtures in the 

Piedmont (Boyce and Knight 1980, Zahner 1982, 

Phillips and Abercrombie 1987). Less intensive 

regeneration practices associated with pinehardwood mixtures are especially important in Virginia, where 81 percent of the total forest land is 

owned by farmers, professionals, and absentee 

landlords who often have limited funds andior a 

limited commitment to carry out intensive forest 

management. 

Research is needed to determine the feasibility of 

low-input woodlot management systems for pinehardwood mixtures which optimize wood production and can be effectively implemented with limited 

funds. For farmers, cost-effective techniques which 

allow for the successful establishment and sustained regeneration of pine-hardwood mixtures 

would increase crop diversification and reduce sensitivity to market fluctuations in livestock and 

agricultural commodities. In addition, low-input cuttural techniques that create mixed forests will enhance environmental quality by providing improved 

soil and water protection, as well as increasing 

species diversity and creating new wildlife habitat. 

'~ssociate Professor. Professor, Research Associate, and Graduate Research Assistant, respectively, Dept, of Forestry, Virginia Polytechnic 

Institute and State University, Blacksburg, VA, 

24061. 

The objectives of this study were to determine the effects of site quality, season of harvest, and four 

even-aged regenerat ion treatments on the growth 

and development of natural hardwood and planted 

loblolly pine following clear felling. 

STUDY AREA 

The study area is located on the upper Piedmont at 

the Virginia Polytechnic Institute and State 

University's Reynolds Homestead Agricultural Experiment Station in Patrick County, Virginia. The 

soils are typical of the Piedmont and are leached, 

severely eroded Ultisols developed from granitic 

and metamorphic bedrock. Slopes range from 2 to 

20 percent with 6 to 8 percent most common. 

Slope exposure is variable and important in determining site quality. The cooler northerly and easterly slopes are normally more productive than 

southerly and westerly aspects. Annual precipitation averages 49 inches and is well distributed 

throughout the year. As a result of the eroded and 

shallow surface horizon, the high clay content of the 

subsurface soil horizon, and summer precipitation 

in the form of infrequent, high-intensity 

thunderstorms, high tree moisture stress is common during the hotter months of July and August. 

The forest stands of the study area are also typical 

of the Piedmont and are composed of mixed oak 

species on medium and poor sites, with yellowpoplar being a main canopy species on the better 

sites. Most of the stands have reverted to forest 

cover following abusive agriculture and abandonment within the past 125 years. High-grading and 

partial cutting have been used indiscriminately in 

the past, and, in most cases, the resulting stands 

have poor quality stems and the species composition has shifted to more tolerant, less desirable 

species. 
METHODS 

Study plots were located in 50- to 80-year-old 

second-growth mixed oak forests on site qualities 

ranging from Slso 48 to 75 feet for white oak (Carmean 1971, Doolittle 1958). Differences in stand 

composition based on the presence or absence of 

site-specific species enabled division of stands into 

two classes of site quality- poor sites with S150 less 

than 65 feet and good sites with S150 greater than 

65 feet. Three plots were located in each of the two 

site classes. Pre-harvest stands contained an 

average of 106 square feet of basal area per acre 

on the poor sites and 11 8 square feet per acre on 

the good sites. Oak species comprised about 59 

percent of the basal area on the poor sites and 34 

percent on the better sites. The dominant species 

on the poor sites included chestnut oak, scarlet 

oak, red maple, and sourwood, with scattered Virginia pine and eastern white pine. White oak, yellow-poplar, red maple, sourwood, and northern red 

oak dominated the good sites. 

The experimental design was a split-split-plot 

designed to evaluate site quality, season of harvest, 

and regeneration treatment. The study contains 

three blocks. Each block contains the two site 

qualities, good and poor, representing the whole 

plot. Whole plots were randomly split into growing 

and dormant season harvest. The dormant season 

split-plots were clear felled with chainsaws and 

whole-tree yarded with rubber-tired skidders between February 21 and March 23, 1983. The growing season harvest was conducted in a similar 

manner between June 21 and July 25, 1983. All 

stems greater than one inch in dbh were felled. 

Four regeneration treatments were randomly assigned to each site class-harvest season unit, representing the second split. Each regeneration plot 

was 98.4 x 98.4 feet and contained one of the following treatments: 

Tl) Clear felling and whole-tree yarding only 

T2) Clear felling, whole-tree yarding, and planted 

loblolly pine seedlings 

T3) Clear felling, whole-tree yarding, herbicide treatment of all hardwood stumps, and planted 

loblolly pine seedlings 

T4) Clear felling, whole-tree yarding, herbicide treatment of all hardwood stumps, planted 

loblolly pine seedlings, and a release treatment 

of pine seedlings. 

Treatments 2, 3, and 4 included planting genetically 

improved 1-0 loblolly pine seedlings from a Virginia 

Piedmont source in March 1984. Seedlings were 

hand planted on a 6.6 x 6.6 feet grid resulting in a 

density of 1000 seedlings per acre. 

The cut-stump herbicide application used in Treatments 3 and 4 consisted of a thin stream of undiluted herbicide applied to the cambial region of 

the stump immediately following cutting. All 

hardwood stumps were treated at an average rate 

of 0.85 oz. of chemical per square foot of basal 

area. Individual stems in the regeneration treatments 3 and 4 split-split-plots were treated with one 

of the following: triclopyr ([(3,5,6-trichloro-2- 

pyridinyl)oxy] acetic acid as Garlon-4g 61 6 percent EC); gl y~hosate (N-(phosphonomet hyl) gl ycine 

as Roundup3 41.0 percent SL); dicamba (3,6- 

d ic hlor-2-met hoxybenzoic acid as Banvel CST~ 

10.6 percent SL); picloram + 2,4-D (4-amino-3,5,6- 

trichloropicolinic acid + 2,4-dichlorophenoxy 

acetic acid as Tordon-1 01 -R' 5.4 percent SL); or 

hexazinone (3-cyclohexyl-6-(d imet hylamino)-1 - 

methyl-l,3,5-triazine-2,4(1 H,3H)-dione) as Velpar 

L~ 25 percent SL) (Zedaker and others 1987). 

Thus, the hardwood reduction and pine response 

reported for treatments 3 and 4 represent an 

average response for all these herbicides. 

Treatment 4 plots received a pine release in March 

1985. Plots were randomly split so that each half 

received a basal bark spray or a soil-applied herbicide release treatment. The basal-bark-spray 

release method consisted of 4 percent triclopyr 

(ester) (as Garlon-4$ 61.6 percent EC) diluted with 

diesel fuel and applied with a backpack sprayer. 

The mixture was applied to the bottom 6-8 inches of 

treated stems until runoff. All stems within 3.3 feet 

of loblolly pine seedlings were treated. An average 

of 0.36 gallons of triclopyr and 8.8 gallons of diesel 

fuel were used to release 526 loblolly pines per 

acre. An average of 4.7 man-hours was required to 

treat one acre. The soil-active herbicide was applied as 50 percent hexazinone as Velpar L"5 

percent SL in water with a spotgun. The mixture 

was applied in six evenly spaced 0.084-ounce (2.5 

ml.) spots arranged in a 3.3-feet-radius circle 

around each loblolly pine seedling. An average of 

one gallon of hexazinone was used to release 526 

loblolly pines per acre. The time required to treat 

one acre averaged 2.7 man-hours. For this report, 

the data for the different herbicide release plots 

were combined and represent the mean response 

of low-input release treatments. 

To evaluate the effects of site quality, harvest date, 

and regeneration treatment, two 32.8 x 32.8-feet 

measurement plots were located within each splitsplit-plot. All stems 2 inch DBH were measured for 
diameter and height. In each measurement plot 

two 6.6 x 6.6 feet nested plots were randomly located to measure stems 2 inch DBH The height 

and crown diameter of all rootstocks in these 

nested plots were measured. Species-specif ic 

regression equations developed by Zedaker and 

others (1987) were used to convert. crown v~i~mes 

of hardwood root stocks to basal area at breast 

height. Statistical anafyses were pedorawed using 

SAS procedtrres for general linear model analysis of 

variance. 

RESULTS AND DISCUSSION 

Five years after establishment hawest: timing and 

low input regeneration treatments have resuited in 

significantl y different stand conditions Stands harvested in the growing season, w~rhout subsequent 

herbicide treatment, carry about half of the 

hardwood basal area of those kantested In the elormant season (table 1 ). The additrsn sf pines to the 

nat urail y regenerated hardwood stands has had little impact on hardwood basal area to date. Stump 

treatment with herbicides resulted in an average 

basal area reduction of 63 percent. Another 60 percent average reduction occurred as a result sf backpack-applied herbicide release treatments, Pine 

regeneration treatments had minor effects on 

hardwood species composition (table 2). Differences in susceptibility of the hardwood species to the 

herbicides used would account for most of these 

changes. For example, half of the ptots released in 

1985 were treated with hexazinone. Yellow-poplar, 

which increased in basal area composition 14 percent from stump-treated to stump-treated and 

released ptots, is known to be resistant to 

hexazinone 

Pine basal area increased significant1 y with increasing herbicidal control of regenerating hardwoods 

(table 3). Pine basal area in stump-treated and 

released plots was an order of magnitude greater 

than that for non-herbicided plots in stands harvested during t he dormant season. Harvesting lowquality hardwood stands during the growing season 

alone accounted for an average increase of over 

200 percent in pine basal area. Rescheduling dormant season hawests to the growing season would 

be as beneficial in increasing pine basal area as 

st urnp treatment and subsequent release. The 

growing-season-hawested, planted-pine plots 

averaged 88 percent of the basal area of dormantseason-hawested, stump-treated, and released 

pfots. Still, low-input herbicide treatments resulted 

Table 1, Summary of hardwood basal area by season of harvest and 

regeneration treatment five years fo lowing clear felling 

of Virginia Piedmont hardwood stands 1 

REGENERATION 

TREATMENT 

HARVEST SEASON 

Dormant Growing Mean 

- - - - - ... (sq. ft./ac.) - - - - - 

Clearcut, Pine 57.1 24,7 403 

Clearcut, Stump 

Treat, Pine 

Clearcut, Stump 6+!5 5 * 3 5.9 

Treat, Pine, Release 

'~i~ificance of main effects: Harvest p = .26 

Treatment p = ,005 
Table 2. Relative hardwood basal area composition by regeneration 

treatment five years after clear felling of Virginia 

Piedmont hardwood stands. 

REGENERATION TREATMENT 

SPECIES 

Clearcut Clearcut, Clearcut, Clearcut, 

Pine Stump Treat, Stump Treat, 

Pine Pine, Release 

Red Maple 

Yellow-Poplar 

Sourwood 

Chestnut Oak 

White Oak 

Scarlet Oak 

Black Cherry 

Black Locust 

0 ther 

Table 3. Summary of pine basal area by season of harvest 

and regeneration treatment five years following 

clear felling of Virginia Piedmont hardwood stands . 

-- 

HARVEST SEASON 

REGENERATION 

TREATMENT Dormant Growing Mean 

- - - - (sq. ft./ac.) - - - - 

Clearcut, Pine 0.4 3.9 2.1 

Clearcut, Stump 

Treat, Pine 

Clearcut, Stump 4.4 11.4 

Treat, Pine, Release 

Mean 2.0 6 9 

'significance of main effects: Harvest p = .02 

Treatment p = .001 
in large significant increases in pine dominance. 

Spending $10 to $1 5 per acre for stump treatment 

resulted in a 43 percent increase in pine basal area. 

An additional investment of $45 to $55 for backpack release resulted in an additional 140 percent 

basal area increase. Clearly, the 2,700 percent difference in the range of pine response between the 

poorest and the best treatmenti harvest combination 

leaves ample room for customization or optimization in stand pine-hardwood ratios (table 3). 

Predicting future stand conditions from five-year-old 

data is tenuous at best. Hardwood basal area in 

the natural regeneration plots and in the pine 

planted but non-herbicided plots is 30 to 50 percent 

of its probable maximum for stands of moderate 

site index. The rate of hardwood basal area growth 

should be decelerating rapidly. Conversely, pines 

should just be approaching the point of rapid acceleration in basal area growth. Past experience 

tells us that, even in stands that were not stumptreated or stump-treated and released, pine basal 

area will increase dramatically relative to hardwood 

basal area. Exactly how much of an increase will 

occur is currently unpredictable but is probably dependent on site conditions and the current relative 

dominance of hardwood and pine species. The extent to which site conditions are favorable to the silvical characteristics of each tree species will 

determine much of the final outcome in stand 

dominance. 

Harvest timing and regeneration treatments have already created differences in mean height (table 4). 

Mean pine height exceeds mean hardwood height 

in all cases except in non-herbicided, dormantseason-harvested plots. Reductions of hardwood 

height and basal area as a result of the herbicide 

treatments have resulted in significant increases in 

pine height. However, the mean height of many of 

the most dominant hardwood species still exceeds 

that of the pines (tabie 5). The mean height of sourwood, the third most dominant species, exceeds 

that of loblolly pine in all but the stump-treated and 

released plots. Black cherry and black locust are 

also keeping pace in many of the stands. If pine 

domination is desired, release is necessary to insure that no hardwood species are taller than the 

pines. 

Table 4. Summary of mean loblolly pine and hardwood heights by season 

of harvest and regeneration treatment five years f llowing P clear felling of Virginia Piedmont hardwood stands . 

HARVEST SEASON 

REGENERATION 

TREATMENT 

Dormant Growing Mean 

Pine Hardwood Pine Hardwood Pine Hardwood 

Clearcut -- 5 * 6 -- 4.8 -- 5.2 

Clearcut, Pine 5.3 6.3 8.5 5.9 6-9 6,I 

~learcut, Stump 6.4 5.1 9.0 4.5 7.9 4*8 

Treat, Pine 

Clearcut, Stump 8,7 2,3 10.8 2.1 9.8 2.2 

Treat, Pine, 

Release 

'~i~ificance of effects: Harvest: pine p = .02, hardwood p = .IT. 

Treatment: pine p = .02, hardwood p = .001. 
Table 5, Mean height of dominant hardwood species by regeneration 

treatment five years after clear felling of Virginia 

Piedmont hardwood stands. 

REGENERATION mEAmEm 

SPECIES 

Clearcut Clearcut, Clearcut, Clearcut, 

Pine Stump Treat, Stump Treat, 

Pine Pine, Release 

Red Maple 

Yellow-Poplar 

Sourwood 

Chestnut Oak 

White Oak 

Scarlet Oak 

Black Cherry 

Black Locust 

In the first five years following harvest, hardwood 

regeneration development has been extreme1 y 

vigorous, averaging nearly 8 square feet of basal 

area per acre per year, and the dormant season 

harvest having twice the hardwood basal area as 

growing-season-harvested sites. When compared to 

pre-harvest stand composition, there is a significant 

increase in the red maple composition at the expense of the more desirable oak species. In the preharvest stand the oaks represented about half the 

total basal area (Kays and others 1 985). Five years 

following harvest the oaks represent less than 20 

percent of the total basal area. Sourwood is a 

dominant species in terms of height; however, as 

the stand closes it is expected that it will quickly 

lose its present height advantage and assume an intermediate or perhaps co-dominant canopy position. 

CONCLUSIONS 

The study has demonstrated that by using appropriate combinations of harvest season, herbicide stump treatment at the time of tree felling, 

and post-planting herbicide release of pine, it is possible to develop forest stands composed of mixed 

hardwoods, hardwood-pines, pine-hardwoods, or 

plantations dominated by lobloll y pine. These 

various species mixes are achieved with minimal 

costs and environmental perturbations. What 

remains is to quantify and optimize yield responses 

that can be obtained from these low-input methods 

to create mixed hardwood-pine stands. 

ACKNOWLEDGEMENTS 

This research was supported by the Silviculture and 

Management of Pine-Hardwood Mixtures in the 

Piedmont Research Vdork Unit (FS-SE 41 05) , USDA 

Forest Service, Southeastern Forest Experiment Station, Glemson, South Carolina; the Reynolds Homestead Agricultural Experiment Station; the Robert 

Kennedy Fund; and the Mclntire-Stennis Fund. 
LITERATURE CITED 

Boyce, S.G; Knight, H.A. 1980. Prospective in 

growth of southern hardwoods beyond 1980. 

Res. Pap. SE-203. Asheville, N.C.: U.S. Department of Agriculture Forest Service, Southeastern 

Forest Experiment Station. 33 p. 

Carmean, W.H. 1971. Site index curves for black, 

white, scarlet, and chestnut oaks in the Central 

States. Res, Pap. NC-62. St. Paul, Minn.: U.S. 

Department of Agriculture Forest Service, North 

Central Forest Experiment Station. 8 p. 

Doolittle, W.T. 1958. Site index comparisons for 

several forest species in the southern Appalachians. Soil Science Society of America 

Proceedings 22: 455-458. 

Kays, J.S.; Smith, D. Wm.; Zedaker, S.M. 1985. 

Season of harvest and site quality effects on 

hardwood regeneration in the Virginia Piedmont. 

In: E. Shoulders (ed). Proceedings of the Third 

Biennial Southern Silvicultural Research Conference. USDA Forest Service Gen. Tech. Report 

SO-54 New Orleans, LA. pp. 137-1 45. 

Phillips, D.R.; Abercrombie, J.A., Jr. 1987. Pinehardwood mixtures--a new concept in 

regeneration. Southern Journal of Applied 

Forestry 1 1 : 192-1 97. 

Zahner, R. 1982. Some benefits of establishing 

planted pine-natural hardwood mixtures. In: 

Proc. Second American Forestry Forum. Clemson University. pp. 13-23. 

Zedaker, S.M.; Lewis, J.B.; Smith, D. Wm.; Kreh, 

R.E. 1987. Impact of season of harvest and site 

quality on cut-stump treatment of Piedmont 

hardwoods. Southern Journal of Applied Forestry 

1 1 : 46-49. 
CONVERTING LOW-QUALITY HARDWOOD STANDS TO 

PINE-HARDVVOOD MIXTURES 

Charles E. ~c~ee' 

- low-quality hardwood stands on the Cumberland Plateau and Western Highland Rim 

01 Tennessee were harvested by shearfelllng and on-s~te chipprng Feaslbrl~ty of tntroduc~ng loblolly pfne into these harvested stands with mlnrmum or no slte preparation is explored The resulttprg p~ne-hardwood m~xtures are now 11 and 7 years old This paper descr~bes these mixtures, 

evaluates the plne and hardwood components, and d~scusses some of the problems and opportunrtlss assocrated with p~ne-hardwood mfxtures Current compos~tion, freedom to grow, and 

general outlook for further development are cons~dered An lntens~ve harvest as prov~ded by the 

sksarrng IS clearly an rmportant factor In the low-cost conversion of poor hardwood stands to pinehardwood mixtures 

ONIWODIUGTBg3N 

Low-quality hardwood stands on the Cumberland 

Plateau and the Western W ighland W im are good 

candidates For either conversion to pine or for 

natural regeneration to mixed hardwoods. These 

stands also oger good opportunities for planted 

pine-natural hardwood mixtures. The purpose of 

this paper is to describe the development of pinehardwood miaures following intensive harvesting, 

limited site preparation, and the planting of loblolly 

pine 

An approlack to mixed stand development is 

prescribed by some of the philosophy that underlies our recent recognition of pine- hardwood mixtures as a management entity. The recognition by 

this symposium of the impoflance of the pinehardwood type is a giant step Coward in forest 

management. Ten years ago, when Dan %ims and 

a few others seriously began considering pinehardwood mixZures, we were often met with open 

derision. The pine groups looked upon anyone that 

would tolerate, much less promote, a hardwood in 

a pine plantation as a heretic. The hardwood 

groups were not interested in pine as an opportunity So it is with a great deal of personal satisfaction that I see ahis symposium called to order. Yet, 

we should not get so caught up In the euphoria of 

the moment that we overlook some silvicultural, 

ecological, and economic traps and pitSalls that 

may lurk in the pine-hardwood forest. 

One trap is the temptation ta classify as desirable 

those pine-hardwood mixtures that are only 

tolerable, in my paper today I will present some 

situations that are tolerable; these situations are 

'~kls work was accompfished wh~le Br Charles 

E McGea was Principal S~lv~culttlrrsr Sawanee SIIvrculfure kslbaratary ma~ntarned at Sewanee, Tennessee by the Southern Forest Experiment 

Starton, Forest Service--USDA, in cooperation with 

the Unrversity of the South 

probably not the most desirable development, and 

for some landowners, they may not even be acceptable. One key to tolerance of pine-hardwood mixtures is cost. For example, a landowner spending 

$250 per acre for site preparation is not likely to 

tolerate any invasion of hardwoods in the plantation. On the other hand, a landowner spending $30 

per acre for competition eontroi in pine conversion 

may tolerate many hardwoods and accept a pinehardwood mixture. However, wo should not camfuse tolerance with desire. The landowner spending 

$30 per acre would usually desire a pure pine stand 

if he could get it for $30 but will accept or tolerate a 

mixture at that reduced cost. 

Another trap involves extrapolating pine-hardwood 

results across site-quality zones. My data will sho~ 

results that probably would not be achieved if the 

quality of the site were only slightly better. In our interpretations of pine-hardwood relationships we 

need to be as precise as possible with site-quality 

data, and when we cannot be precise we should be 

very careful with recommendations. 

The successional status of pine-hardwood stands 

may also provide a high risk temptation. Some 

landowners may become so pleased with a pinehardwood mixture that they will attempt 10 perpetuate the mixture. While flexibility of 

management is one of the great aMributes of pinehardwood mixtures, perpetuation of a precise mixture may be difficult and costly to accomplish. In 

many cases the maintenance of a stable mixfure 

may be more difficult than moving the stand toward 

pure pine or pure hardwood. 

A final pitfall is the temptation to use a pinehardwood mixture as an excuse for having made 

poor site preparation. As we recognize the benefits 

of pine-hardwood mixtures, we should not let our increased tolerance for mixtures allow an increased 
tolerance for poor workmanship in conversion 

areas where pure pine stands are a bonafide goal 

of the landowner. 

The Following discussion applies to pine-hardwood 

mixtures on the Cumberland Plateau and the 

Western Highland Rim. Complete descriptions of 

study areas and methods are available in earlier 

publications (McGee 1986, McGee 1980, Sims and 

st hers 1 984). 

STUDY METH)-IODS 

The 40-acre study site, located on top of the Cumberland Plateau, supported a fully-stocked lowquality stand of mixed hardwoods. Due to shallow 

soils burning, and high grading, most of the larger 

trees were culls. 

The study area was separated into 1 -acre plots. Six 

of these plots were designated for planting to loblolly pine Site index for oak for the general area was 

estimated prior to logging to be about 60-65 feet at 

age 50. Site index based upon the height of the 1 1 - 

year-old iobtolly pine trees on the 6 plots ranged 

from 53 ta 57 feet at 25 years. Desirable hardwood 

species on this area included the oaks, yellow 

poplar, black cherry, and hickory. Undesirable 

species for timber included red maple, dogwood, 

sassafrass, and blackgum. 

The harvest. Harvesting of the low-quality stand 

was by shearing with a Brott Feller Buncher to 4 inches d bh; skidding the trees to a central location; 

chipping the entire tree; and piling the chips for 

later removal. 

The site preparation. Three of the six plots were 

randomly selected to receive a herbicide injection. 

Residual trees over 4 112 feet tall were injected with 

Tordan 181 in the spring following harvest. Later in 

the summer, trees that had escaped the injection 

were retreated. Control of residuals on these three 

plots was almost 100 percent effective. The untreated plots contained about 300 residuals between 1 and 4 inches dbh. The residuals occurred 

mostly in clumps. 

The planting. boblolly pines from a regional source 

were pianted at a spacing of 8 x 10 feet. The planting areas constituted a subplot and the relationships of planted pines to natural hardwoods were 

based upon suwival, grovvth and development 

within and between these 8 x 10 foot subplots. 

There were 143 subplots on each central li4-acre 

measurement area. 

The Western Hiahland Rim Study Area 

The 40-acre study area in Humphries County supported a fully-stocked, mixed-hardwood overstory 

with many intermediate stems and a wide variety of 

understory plants. Soils were mostly cherty and 

relatively shallow. Oak site index estimates on the 

area ranged from 57 to 74 feet at 50 years. 

Desirable timber species included the oaks, the 

hickories, black cherry, white ash, and yellowpoplar. Blackgum, red maple, dogwood, and sourwood were the most predominant undesirable timber species. 

The harvest. The harvest was conducted in September and October 1980. All trees over 1 -inch d bh 

were sheared and skidded to central locations for 

chipping. The shearing and skidding removed almost all standing woody vegetation from the study 

area. 

The Planting. Loblolly pines were planted at a 10 x 

10 foot spacng in March 1981 on 8 1 -acre plots. 

Site preparation to release the planted pines from 

encroaching hardwoods was planned for 4 of the 8 

plots. However, to date no site preparation or 

release has been done. 

In the interior of each 1-acre plot, 121 of the 10 x 10 

foot subplots were established with a planted pine 

in each subplot center. The relationships of the 

planted pines to the natural hardwoods were based 

upon survival, growth, and development in these 

subplots. 

RESULTS 

Pine Establishment 

Because the objective of the investigation reported 

here was to successfully introduce a component of 

loblolly pine into a cutover hardwood forest at 

moderate cost, then the goal must be judged successful. Survival rate of planted pines was above 75 

percent on 13 of the 14 1 -acre study plots. Clearly, 

pine dominance was related to the intensity of the 

harvest and the extent of site preparation. 

On the 6 plots on the Cumberland Plateau, average 

heights of the planted pines after 11 years ranged 

from 24 feet to 31 feet (table 1 ). Site index ranged 

from 52 to 57 feet on a 25-year base. The pines on 

the 3 plots where the residual hardwoods were injected averaged 3 feet taller than those pines on the 

uninjected plots. On the injected plots 79 percent 

of the 8 x 10 foot subplots (planting spaces) contained a dominant pine. On the uninjected plots 57 

percent of the subplots were occupied by a 

dominant pine (figure 1 ). 
Table 1.--Development of the pine component by location and years following treatment 

Location 

and 

treatment 

Height of Free 

Average Average tallest 200 to 

Survival diameter height per acre grow 

Cumberland Plateau: 

Hardwood residuals 

injected 

Hardwood residuals 

not injected 

Highland Rim: 

Shearing 

Shearing 

percent inches feet feet percent 

On the 8 plots on the Western Highland Rim, 

average height of the planted pines after 7 years 

ranged from 13 to 18 feet (table 1). Sixty-nine percent of the 10 x 10 foot subplots (planting spots) 

contained a dominant pine (figure 2). 

The Pine-Hardwood Fliixtm 

In addition to the pines, a component of hardwoods 

grew in each plot (table 2). 

On the 3 injected plots on the Cumberland Plateau, 

about 11 percent of the subplots contained a 

desirable and dominant hardwood. An additional 

11 percent of the subplots contained a dominant 

and undesirable hardwood. These plots contained, 

in addition to the dominant hardwoods and planted 

pines, an average of 225 desirable and 195 undesirable hardwoods per acre at sizes greater than 

1.5 inches dbh. 

On the 3 Plateau plots that were not injected, 16 percent of the subplots contained a dominant 

regenerating hardwood classed as desirable. An 

additional 11 percent of the subplots contained a 

dominant desirable residual hardwood. Thus 84 

percent of the subplots were occupied by a 

dominant loblolly pine or a dominant desirable 

hardwood. These plots also contained 330 

desirable and 336 undesirable hardwoods per acre 

larger than 1.5 inches dbh. 

Through the first 7 years the mixture of dominant 

pine and dominant hardwood appeared to be relatively uniform on the 3 plots on the Plateau that had 

the residual hardwoods injected. The 3 plots 

without injection did have clumps of hardwood 

residuals. Now, after 1 1 years, there is clumpiness 

70 -- 

E? 

60-- k! 50-- 

t;: 

g 40 -- 

ti! 

30 -- 

0 

0I 

0- 

I 

.+----- 

KSIDUALS (INJECT€'? 

pine plus hardwood 

---------- pine 

ESIWALS (NOT INJECTED) ----- pine plus bcprdwood 

pine 

Figure 1 .--Frequency of pine or pine plus a 

desirable hardwood being the dominant tree on 8 x 

10 subplots (planting spots) on the Cumberland 

Plateau. 
Table 2, Characterization of hardwoods, 1.6 inches dbh and larger, by location and years following tmatment 

Desirable hardwoods Undesirable hardwoods 

Location 

and 

treatment 

Subplots Subplots 

where Average Hardwoods where Average Hardwoods 

dominant height per acre dorainant height per acre 

percent feet number percent feet number 

Cumberland Plateau ............................ 11 years after treatment---------------------------- 

Hardwood residuals 10.7 22.5 225 

injected 

Hardwood residuals 26.8 29.0 330 

not injected 

Highland Rim ............................. 7 years after treatment---------------------------- 

Shearing 21.8 14.4 169 9 2 11.7 22 

HESTERN HIGHLAND RIM-SHEARED TO lUVE INCH desirable hardwood. In addition to the dominant 

90 t hardwoods, 169 desirable and 22 undesirable 

I hardwoods per acre larger than 1.5 inches dbh are 

1 supported by these plots. 

80 i 

I DISCUSSION i 

70 1 The hardwood component amid pine plantatisrrs es- 0 

F tablished in cut-over forests is influenced by a wide 0 

0 

0 array of factors. Site preparation, site quality, har- 0 8 6ol ,- fl vest intensity, the original hardwood population and 

I 

10 1 

1 2 3 4 5 6 7 

YEARS SINCE MRVEST 

Figure 2.--Frequency of pine or pine plus a 

desirable hardwood being the dominant tree on 10 

x 10 subplots (planting spots) on the Western Highland Rim. 

on all of the plots. Therefore, instead of a genuine 

mixture sf individual pines and hardwoods, the outlook is for a miaure of clumps. 

On the Western Highland Rim plots, about 22 percent sf the 1 Q x 10 foot subplots are occupied by a 

dominant and desirable hardwood. About nine percent of the subplots are dominated by an unpine spacing are chief factors. In the cases just 

described, intensive harvest, minimal or no site 

preparation, and mediocre site quality have allowed 

the development of pine-hardwood mixtures. 

From several standpoints the plots on the Plateau 

that received no site preparation are of considerable interest. These plots were harvested by 

shearing to a 4-inch diameter limit, which is a practical and achieveable harvesting goal in many locations. The only cost to the landowner was that for 

loblolly seedlings and planting. What is the outlook 

for these 1 1 -year-old plots? 

For the past 6 years, more than 50 percent of the 

planted pines in these plots have maintained 

dominance on the 8 x 10 subplots and are mostly 

free-to-grow (figure 1 ) . Thus, 250-300 pines per 

acre can be projected to be codomiant at about 

age 20 and about 250-300 pines will have died or 

become hopelessly suppressed. The average 

diameter of the dominant pines after 11 years was 

about 4 inches dbh. By age 20, diameters of the 

dominant pines should range from about 5 to 10 inches dbh. Based upon these rough projections, the 

earliest the pine in these plots could be thinned 

would be about age 26-28 when the smaller 

dominant pine would be about 6 inches dbh. 
On these plots, the hardwoods consist of two 

populations: the residuals, which were up to 4 inches d bh at the time of logging, and the natural 

hardwood regeneration, which resulted directly 

from the harvest cut. 

Desirable residuals include the oaks, a few black 

cherry, occasional yellow-poplar and some hickories. Some of these residuals are 10 inches dbh 

and 45 feet tali, They occur mostly in clumps. 

There are very few residuals of undesirable species 

that are dominant at this time. Although the quality 

of the residual hardwoods is medium to low, these 

trees will soon be a source of both hard and soft 

mast. Some of these trees will make tie logs or 

small sawlogs when the pines are ready for thinning 

in about 15 years. 

The desirable hardwood regeneration has much 

greater potential for quality growth than the residual 

hardwoods. This new hardwood growth is 

dominant on 16 percent of the subplots. Quality 

sprouts of white oak, black oak, scarlet oak, a few 

black cherry and an occasional yellow-poplar 

average about 29 feet in height when they dominate 

a subplot. These trees range from 3-5 inches in 

diameter and should be large enough for thinning 

in 15 years. 

Thus, about 27 percent of the 8 x 10 subplots are 

dominated by a desirable hardwood, about 16 percent by an undesirable hardwood and 57 percent 

by a loblolly pine. 

The 8 1 -acre plots on the Western Highland Rim 

were harvested to a 1 -inch diameter limit. When 

this level of utilization can be achieved, great opportunities for low-cost regeneration occur. Seven 

years after planting, with no additional site preparation, the loblolly pine are dominant in 69 percent of 

the 10 x 10 subplots. The average height of all 

planted loblolly is 15.9 feet and the height of the tallest 200 per acre is 18.3 feet. Based upon current 

data, about 250 to 300 pines per acre will be 

codominant for at least the next few years. 

The hardwood component on the Highland Rim 

plots consists entirely of regrowth following the harvest. Desirable hardwoods dominate 22 percent of 

the 10 x 10 subplots. Desirable hardwoods include 

white oak, hickory, white ash, yellow-poplar, other 

oaks, and black cherry. The average height of the 

dominant desirable hardwoods is 14.4 feet. The 

long-range outlook for these desirable hardwoods is 

fair to good. Site quality is adequate to produce 

some good sawtimber in a 60-80 year rotation. Undesirable hardwoods occupy 9 percent of the subplots and the average height of the dominant 

undesirable hardwoods is 1 1.7 feet. 

A landowner would have a choice with the ?-yearold plots on the Highland Rim. Left alone these 

plots will probably maintain a pine-hardwood mixture. Probably less than half of the planted pines 

will be available for thinning at age 22-25. The 

dominant pine component could be increased and 

the potential pine yield increased with immediate 

cleaning and release. The cost of the treatment 

should be carefully weighed against the expected increase in value of the pine. 

CONCLUSIONS 

Intensive utilization of low-quality hardwood stands 

on the Cumberland Plateau and Western Highland 

Rim followed by planting of loblolly pine will 

produce a mixture of pines and hardwoods. The extent of the pine component will increase as the intensity of utilization or site preparation increases. 

Pine-hardwood mixtures on the mediocre sites discussed in this paper present landowners with considerable flexibility, but also require complex 

silviculture and management. The mixed stands 

described in this paper will probably not be considered ideal or optimum by many landowners. 

However, many landowners will accept or tolerate 

the mixlures because the cost of attainment can be 

quite low. These mixed stands provide species diversity and will continue to provide good habitat for a 

variety of wildlife. The economic value of the stands 

in the near future will depend upon markets for 

mediocre to low-quality hardwoods and pine 

pulpwood. The long-term prospects for producing 

mature pines and hardwoods are good. The maintenance of the pine-hardwood mixture beyond the 

first rotation by natural regeneration will be difficult 

and may not be a practical alternative. 

LITERATURE CITED 

McGee, Charles E. 1980. Expanding options for 

reforestation of the Cumberland Plateau. 

Southern Journal of Applied Forestry 4(4): 158- 

162. 

McGee, Charles E. 1986. Regeneration after shear 

felling and chipping of upland hardwoods. Res. 

Pap. SO-224. New Orleans, IA: U.S. Department 

of Agriculture, Forest Service, Southern Forest Experiment Station. 13 pp. 

Sims, Daniel H.; McGee, Charles E.; Gallaway, 

Jerry [and others]. 1984. Mixed pine-hardwood 

stands - a low-cost option for reforestation. 

Forest Farmer 40(10):10-11, 16-1 7. 
WRW CROP TREE PRESENCE IN UPLAND 

PINE-HARDWOOD STANDS RELATED TO SITE QUALITY 

AND PREHARVEST STAND COMPOSITION 

Lawrence E. Nix, Thomas F. Ruckelshaus, and Steven M. ones' 

-Mixed stands of planted loblolly plne and natural-orrg~n upland hardwoods, 5-10 years 

old that had been injected clearfelled and burned to varying degrees were exam~ned in the South 

Caroltna Piedmont to determrne the presence of potent~al crop trees The stands ranged from oldf~eid shortleaf pine to varyzng mlxtures of shortleaf ptne-upland hardwoods prlor to regeneration 

The stands were subdivided Into two drstlnct srte types and crop trees were related to preharvest 

stand compos~tlon and herbrcide treatment effort Site qual~ty exerted a strong Influence only on the 

he~ght of hardwood crop stems but not on any attr~butes of plne crop stems The number and relatrve dom~nance of hardwood stems were negatively Influenced by a h~gh preharvest plne compositisn and herbic~de effort In areas of poor site qualrty as affected pr~mar~ly by aspect, hardwood 

crop tree number was satisfactory (2-300 stems per acre), but he~ght growth was uniformly poor, 

resuit~ng In many potential crop tree stems belng subordinate to the taller planted pines which 

numbered 3-400 stems per acre 

INTRODUCTION 

It has been estimated that 70 to 80 percent of all timberland in the South is held by non-industrial 

private owners (Phillips and Abercrombie 1987). 

This type of landowner typically has multiple goals 

for ownership of forest land (Fontenot and Martin 

1974). Furthermore, most small private owners lack 

the capital needed to convert their existing holdings 

to intensive pine monoculture (Zahner 1982). 

If demand for forest products continues and more 

forest land is removed from production, the large 

proportion of forest lands held by the small private 

owners will need to be as productive as possible, 

commensurate with the diversity of landowning objectives. it is vital for professional foresters to 

develop alternative strategies of management of 

these forests that are acceptable and affordable by 

the small private non-industrial forest owners. 

Since multiple benefits are desired by most private 

landowners, the culturing of pine-hardwood mixtures in lieu of pine monocultures may be a viable 

alternative. Regeneration costs are reduced in such 

culture by about 50 percent, promising good net 

retutns, while wildlife benefits are enhanced by increased browse for deer and increased diversity 

and cover for small game such as quail, turkey and 

rabbit (Phillips and Abercrombre 1987). Squirrels,deer. and turkey benefit from increased mast 

production and den sites provided by hardwood 

miaures (Uhlig 19561, Pine-hardwood miaures 

also provide the best natural protection against outbreaks of the southern pine bark beetle by increasing the distance between pines (Za hner 1 982). 

Stroempl and Beckwith (1 978) list other benefits occurring from interplantirag or underplanting a 

'~ssoc~ate Professor, Graduate Student, and Ass~stanl Professor respectrvely Clemson Univers~ty 

Glemson SC 

b 

desirable species in a stand that is naturally 

developing, i.e,, greater stability against mechanical 

and biological injuries, improved nutrient status, 

and increased aesthetic values. 

Some aspects of pine-hardwood mixtures are in dispute or, at least, open to question. Phillips and 

Abercrombie (1 987) cite as a disadvantage the 

reduced value of intermediate and harvest cuttings 

due to the lower valued hardwood component. 

Stroempl and Beckwith (1978) suggest that the 

return from the more valuable oak should outweigh 

possible reduction in pine production in their 

Canadian study of enrichment planting. Another 

disadvantage is the delay in thinning income (Phillips and Abercrombie 1987); however, as markets 

develop, many hardwood stems of a mixed pinehardwood stand will eventually be as valuable for intermediate products as the pine (Zahner 1982). 

Owners may then be encouraged to improve lowquality hardwood stands by regenerating pinehardwood mixtures with reduced cost for site 

preparation or release (Sims and others 1981 ). 

Data on the amount, type, and growth rates of 

regeneration for both weed and crop trees as they 

relate to site quality and preharvest stand composition are needed to develop strategies for improving 

the quantity and quality of pine and hardwood crop 

trees on harvested upland stands. Cleadelling in 

hardwood stands does little to alter species composition (Zahner 1982). In addition, Trimble (1 973) 

failed to demonstrate conclusive relationships between site quality and abundance or distribution of 

hardwood reproduction. In contrast, Smith (1 979) 

reports that regenerated species compositicrn is dependent on site quality or type of advanced 

reproduction, overstory competition and cuMing intensity in central Appalachian hardwoods. The 

present study was undertaken to relate hardwood 
crop tree presence in developing pine-hardwood 

stands to easily determined preharvest stand conditions and site quality differences on upland Piedmont sites in South Carolina, 

MATERIALS AND METHODS 

In order to assess the effects of site quality and 

prehawest stand composition and treatment on the 

number and quality of crop stems, young stands of 

planted loblolly pine ( and naturalorigin upland hardwo utheastern Piedmont were sampled at nine locations on the 

Clemson University Experimental Forest near Clemson, SC. The preharvest stand compositions 

ranged from a moderately high density stand (90 ft2 

of basal area p percent old-field 

shortleaf pine ( to varying mi>ctures 

and densities of shortleaf pine-upland hardwoods. 

The stands had been clearcut, selectively injected at 

dif-fering levels of effort to reduce undesired species 

and large stump sprouting and were clearfelled and 

burned prior to regeneration. Herbicide treatment 

enort ranged from 5 to 50 man hours per acre. 

Loblolly pine was planted at 8 X 10 feet spacing and 

averaged 70 percent supvival. The stands ranged 

from 5 to 10 years old. 

Measurements of tree height, diameter at 4.5 feet 

height, number of dominant stems per acre and 

crop tree status were taken on 5 one-hundredth 

acre plots located one-half chain apart on the good 

and poor sites at each location. Crop stem 

dominance potential was determined for the nine 

locations by calculating a dominance index based 

on the mean crop stem diameter for both the good 

and poor sites for hardwoods and pines divided by 

the overall stem diameter mean for the given locationlsite combination. Crop tree status was determined by species and site combinations, each tree 

being a crop tree or not (Zahner and others 1985). 

Crop trees were required to have all of the following 

characteristics: dominant or codominant canopy 

position, good stem form, and commercial species, 

e.g., loblolly pine (planted) or hardwoods of seedling or basal sprout origin consisting of southern 

"Good" and "'poori' site selection was based on a 

landscape ecosystem model developed by Jones 

(1 988). This ecological approach to classification 

identifies sites with equivalent productive potential 

on the basis of the interaction of landform, soils, 

and vegetation (Barnes 1982). This site classification method essentially identifies a soil moisture 

gradient ranging from xeric, upland fiats with thin, 

clayey soils to mesic, lower slopes with northerly 

and easterly aspects and roamy soils. This study 

was confined to the intermediate and sub-xeric portions of the soil moisture gradient where site productivity is relatively low. Site index (base age 50 

years) ranged from 70 to 80 For mixed oaks and 

from 60 to 75 for shoflleaf pine. Study sites were 

restricted to the upper one-third slope position and 

soils were clayey with the clayey argillic horizon occurring within 12 inches GF the soil surface. Aspect 

varied from northerly to southerly slopes. The 

"good sites were northerly aspects and the "poor" 

sites were generally southerly aspects in this study. 

Data were analyzed using the General linear 

Models procedure with analysis of variance, and 

linear and nonlinear regression analysis procedures 

of the SAS statistical computer package (SAS 

1 985) l ndependsnt variables used in the3 analysis 

were previous stand basal area per acre (PBA), sits 

quality (good vs. poor), man-hours per acre (MH) 

expended in site preparation or release activity 

prior to the planting of pine, and age of the young 

stands. 

RESULTS AND DISCUSSION 

Hardwood crop tree height was the vilriabie most affected by site quality, whereas pine crop tree height 

was not aNected (table 1 ). Site quality, as 

delineated in this study, had little effect on any of 

the other crop tree variables of either pine or 

hardwoods (table 1 ). However, pine crop trees 

were significantly larger, more numerous, and 

higher in dominance potential (as measured by 

dominance index in this study) than were 

hardwood crop trees on both good and poor sites 

(table 2). 

Table 1.--Effects of site quality on crop tree characteristics in 

young pine-hardwood stands of the South Carolina Piedmont 

Hardwood Bianreter (in) 1.8 1.7 0.1 NS 

Height (ft) 16.9 15.3 1.6 ** 

Crop treesjac 238 262 24 NS 

Dom. index 0.79 0.78 0.01 NS 

Fine Biarneter(in) 2.6 2.7 0.1 NS 

Height (ftf 18.6 18.4 0.2 NS 

Crop tree/ac 39 3 344 49 HS Don. index 1.16 1.19 0.03 NS 

** Highly simificant difference, alpha = 0.01, 

IUS No significmt difference* 

Dominance index is the ratio of crop tree stern diameter to 

plot mean stem dimeter. 
Table 2.--Comparison of young pine and hardwood crop tree 

characteristics on good and poor sites in the Piedntont of 

South Carolina 

Good Site Poor Site 

Variable Pine Hardwd. Diff. Pine Hardwd. Diff. 

Diameter (in) 2.6 1.8 0.8 ** 2.7 1.7 l.O9* 

Height(ft) 18.6 16.9 1.7"" 18.4 15.3 3.1** 

Crop trees/ac 393 238 155 ** 344 262 82 * 

Doui. index 1.16 0.79 0.37" 1.19 0.78 0.41 ** 

** Highly significant difference, alpha = 0.01. 

* Significant difference, alpha = 0.10. 

There were more hardwood crop trees per acre on 

the poor sites, but more pine crop trees on the 

good sites, though the differences were not statistically significant (table 1 ). This apparent site effect 

contributed strongly to the widening gap between 

numbers of crop trees of pine versus that of 

hardwoods on the good sites (table 2). The difference in all other crop tree variables (diameter, 

height, and dominance index) between pines and 

hardwoods, actually was least on the good sites, implying a greater response of the hardwood crop 

trees to site quality than that of the pines. Although 

this difference in responsivity is often noted, the 

reasons are obscure as the indeterminate pine 

should prove more opportunistic than the mostly 

determinate hardwoods (Zahner 1982). Perhaps 

the presence of the site responsive yellow-poplar 

among the mostly oak hardwood crop trees in this 

study provides some explanation for this site 

response anomaly. As the stands age, site conditions favor the pine crop trees over the hardwood 

crop trees, especially on the poor site type where 

the differences in size and number are greatest 

(table 2). With a density of 3-400 trees per acre and 

such a wide gap in diameter, height, and 

dominance potential (dominance index) at these 

ages (5-1 0 years), the pine crop trees will likely 

dominate the stand in another 10 years (by age 15- 

20 years). The hardwood crop trees show little indication of "catching up'' with the pines with 

passage of time, i.e., differences have changed little 

in the 5-year time span between the youngest (5 

years old) and the oldest (1 0 years old) stands in 

the study. This conclusion is reinforced by obsewation of some older (15-25 year old) mixed stands 

near the study sites, where the loblolly pine component has completely dominated most of the 

stands after crown closure occurred. 

Size, number and dominance potential of pine and 

hardwood crop trees were not significantly linearly 

related to preharvest stand composition as 

measured by previous pine basal area. Number of 

hardwood crop trees per acre, however, showed a 

strong linear relation to previous stand basal area 

(PBA) (table 3). Crop tree size and dominance 

were generally positively but not significantly correlated with PBA, although dominance index of 

hardwood crop trees was negatively correlated with 

PBA (table 3). There is little explanation for the 

reversal in the correlations except that one would 

logically expect all the hardwood crop tree characteristics to be negatively correlated with PBA, especially the number of crop trees per acre, because of 

the reduced potential for hardwood reproduction 

with increasing density of stand overstory. 

However, with an increase in overstory density 

there may be a decrease in size with an increase in 

number of hardwood stems in the understory of the 

stands. This increase in smaller stems also may be 

involved in the response to the herbicide site 

preparation-release effort. 

Table 3.--Crop tree characteristics as related to previous stand basal 

area (PBA) and man hours of herbicide effort (MI) in young 

pine-hardwood stands in the South Carolina Piedmont 

Relation to PBA Relation to 

Linear Nylinear Linear Npnlineer 

Species variablea R value R value R value R value 

Hardwood 

Diameter 0.51 NS None -0.38 NS None 

Height 0.30 NS None None None 

Croptrees/ac 0.74. 0.59. None 0.90 

Dom. index -0.32 NS None -0.54 NS None 

Pine 

Diameter 0.47 NS None None None 

Height 0.50 NS None None None 

Crop trees/ac None None 0.66 * None 

Dom. index 0.44 NS None None None 

Significant at alpha = 0.01 

NS Not Significant at alpha = 0.10 

a Where R or R* values were less than 0.30 and not significant 

at alpha 0.10, no relationship was assumed between variables. 

An analysis of the effects of the intensity of preharvest site preparation-release efforts as indicated by 

stand records of man hours expended per acre 

(MH) on number and size of crop trees produced 

mixed results. Release efforts appeared to both increase and decrease crop tree numbers. 

Hardwood crop stems increased as MH increased 

to 20-25 hours per acre, but then decreased with 

further release-site preparation effort. The range of 

MH in the stands was 5 to 50 hours per acre and 

graphical analysis indicated that, response to MH 

was non-linear. The effects of level of MH on one of 

the nine stands evaluated was confounded by earlier stand treatments, including beetle-killed pine 

removals and axe-girdling of hardwoods. When this 

questionable stand was deleted from the analysis, 

the non-linear relationship was strengthened significantly by fitting a third-degree polynomial, the 

cubic regression. The coefficient of determination 

for this equation is strong (R* = 0.898, p = 0.019) 

and lends credence to the assumption of nonlinearity in the relationship (table 3). This inference 

is only logical if one assumes that at low MH ( 20-25 

hours) mostly large stems or stumps are treated, 
whereas, at high MH treatment is extended to an increasing number of smaller stems, thus reducing 

potential hardwood crop trees in the future stand. 

As expected, the number of pine crop trees per 

acre was significantly and positively correlated with 

MH (R = 0.67 at alpha = 0.05). Another relatively 

strong but unexpected relationship was found in the 

positive and statistically significant correlation of the 

number of hardwood crop stems per acre with 

stand age (R = 0.58 at p = 0.099). This strong correlation suggests that almost all of the hardwood 

reproduction being examined in this study is seedling or small sapling origin, rather than large 

stump (4-1 0 inch diameter) sprout origin. 0 bservations in the field favor this conclusion as many of 

the crop hardwood stems in the study areas are associated with small stumps ( 3 inches groundline 

diameter) or have no evidence of stumps at all. 

The pattern of development of seedlings or small saplings released by the harvest of these stands is 

commensurate with a characteristic seedling or 

small sapling lag in development for several years 

followed by an increase of height growth (after 5-6 

years) to reach a crop tree dominant stem status in 

the stand. There is also a relatively high proportion 

of crop-quality trees within the total number of 

dominant hardwood stems in the stands, e.g., 79-85 

percent. This high proportion of crop-quality stems 

suggests either that the various degrees of post harvest burning have made a substantial contribution 

to the quality of sprout origin crop stems as suggested by Phillips and Abercrombie (1 987) or that, 

again, most of the crop stems were of seedling or 

small sapling origin (the best "quality" stems) because many larger stems were in fact injected with 

herbicide prior to stand harvest. The smaller stems 

would have escaped herbicide application due to 

their number and size at the time the site preparation-release work was done, and after overstory 

removal, clearfelling and/or burning would have 

been released to provide a major proportion of the 

hardwood reproduction, 

Following harvest, most desirable natural hardwood 

regeneration develops from stump sprouts (Sims 

and others 1981). Rot is not as significant in sproutorigin stems as once was thought (Smith 1979) and 

the incidence of decay is less in basal sprouts 

originating close to the ground which can be encouraged by prescribed fire following harvest 

(Augspurger and others 1987; Phillips and 

Abercrombie 1987). Growth rates of stems of 

sprout origin, however, are usually impressive. 

Height and diameter of yellow-poplar and red oak 

sprouts can be as much as double that of seedlings 

at age 12 (Smith 1979). Small stumps are still the 

most desirable coppice regeneration since they 

tend to produce a minimum number of sprouts and 

still give rapid height growth (Augspurger and 

others 1987). In the oak-pine region of the 

Southeast, Zahner (1 982) reports that oak sprout 

regeneration grows more rapidly than pine for the 

first 10-20 years following establishment, but lobloll y 

pine eventually outgrows even the best oak stems 

by 10 to 20 feet in height by age 50 years on good 

sites. In the present study, however, the planted 

loblolly pines are already well ahead of the 

hardwoods. 

CONCLUSIONS 

The fact that a high proportion of the dominant 

hardwood stems in this study are crop-quality, but 

are so far behind the planted pine crop stems at 

this stage suggests that they are in fact of seedling 

or very small sapling sprout origin. The use of herbicides to reduce large stump sprouting may have 

contributed to this condition. Also, despite the fact 

that "good" and "poor" sites were delineated in each 

stand, the overall site quality is poor, as suggested 

by the essentially su b-xeric classification of these 

sites by Jones (1 988). Perhaps the stands c h~sen 

are not well-suited for hardwood crop tree development and are essentially "pine" sites as the future is 

likely to prove. Nonetheless, the presence, at these 

ages (5-1 0 years), of a reasonable number of 

hardwood crop tree stems per acre (2-300) in a 

"free to grow" status is encouraging in view of their 

substantial contribution to the desired diversity and 

achievement of the multiple use objectives of such 

stands. The importance of the hardwood crop trees 

in the future of these stands may well depend on 

the spacing of the dominant pines. Obviously, the 

wider the pine spacing the more likely the 

hardwood crop stems will remain in at least a 

codominant canopy position. At a pine stocking 

much higher than the 300 or so stems per acre observed in this study, the hardwood crop stems are 

likely to be relegated to a midstory role in the future. 

ACKNOWLEDGEMENTS 

The authors wish to thank James D. Senson and 

Jon E. Barry, Forester II and graduate student, 

respectively, Department of Forestry, Clemson 

University, for their able assistance in collecting 

field measurements. 
LITERATURE CITED 

Augspurger, M. K.; Van Lear, D. H.; Cox, S. K.; Phillips, D. R. 1987. Regeneration of hardwood 

coppice following clearcutting with and without 

prescribed fire. In: Proceedings, 4th Southern Silvicultural Research Conference. p. 89-92. Atlanta, 

GA, NOV. 4-6, 1986. 

Barnes, B. V.; Pregitzer, K. S.; Spies, T. A.; 

Spooner, V. H. 1982. Ecological forest site classification. Journal of Forestry 80:493-498. 

Fontenot, R. W.; Martin, C. B. 1974. Characteristics 

of owners of small timber tracts in southwest 

Louisiana. LSU Forestry Note 106. Baton Rouge, 

LA. 4 pp. 

Jones, S. M. 1988. Old-growth forests within the 

Piedmont of South Carolina. Natural Areas Journal 8:31-37. 

Phillips, D. R.; Abercrombie, J. A., Jr. 1987. Pinehardwood mixtures - a new concept in 

regeneration. Southern Journal of Applied 

Forestry 1 1 (4): 1 92-1 97. 

SAS Institute, Inc. 1985. SAS User's Guide: Statistics, Version 5 Edition. Cary, NC: SAS Institute 

Cnc., 1985. 956 pp. 

Sims, D. H.; McGee, C. E.; Galloway, J.; 

Richman, R. 1981. Mixed pine-hardwood stands - 

A low cost option for reforestation. Forest 

Farmer, Sept. 1981 : 10-1 1 ,I 6-1 7. 

Smith, H. C. 1979. Natural regeneration and intensive cultural practices in central Appalachian 

hardwood stands using clearcutting and selection 

cutting practices. In: Proceedings, John S. Wright 

Forestry Conf.: Regenerating Oaks in Upland 

Hardwood Forests, p. 30-42. Purdue University, 

W. Lafayette, IN, 1979. Feb. 22-23, 1 979. 

Strsempl, G.; Beckwith, A. F. 1978. A successful red 

oak-red pine plantation. Forest Research Note 

17, Ministry of Natural Resources, Ontario, 

Canada. 3 pp. 

Trimble, G. R. 1973. The regeneration of central Appalachian hardwoods with emphasis on the 

effects of site quality and harvesting practice. 

USDA For. Serv. Res. Pap. NE-282. 14 pp. 

Uhlig, H. C. 1956. The gray squirrel in West Virginia. 

Conser. Comm. of West Virginia Bull. No. 3. Charleston, WVA. 83 pp. 

Zahner, R. 1982. Some benefits of establishing 

planted pine-natural hardwood mixtures. In: 

Proceedings, Second Annual Forestry Forum: 

Cost Effective Regeneration Practices, p. 1 3-23. 

Clemson University, Clemson, SC., March 16, 

1982. 

Zahner, R.; Myers, R. K.; Hutto, C. J. 1985. Crop 

tree quality in young Piedmont oak stands of 

sprout origin. Southern Journal of Applied 

Forestry 9(1): 15-20. 
A COMPARISON OF LOBLOLLY PINE GR W AND 

YIELD ON PURE PlNE AND MIXED PINE-HARDWOOD 

SITES 

James D. Haywood and John R. ~oliver' 

mstract. -The case histories of four loblolly pine (Pinuq L.) sites were examined to determine 

if differences in growth and yield could be associated with stand type. The stand types were pure 

loblolly pine and mixed loblolly pine-hardwood, All sites were located on sift loam soils, and mechanical site preparation was carried out on all sites before regeneration, The pure loblolly pine sites had 

greater rates of individual tree growth and yielded more inside-bark volume per acre than pine trees 

on the mixed Ioblolly pine-hardwood site, Pure loblolly pine yielded approximately 830 to 1,520 

ft3iac 9 years after site preparation. In contrast, loblolly pine trees on the mixed pine-hardwood site 

yielded only 152 ft3i'ac after 9 years. 

INTRODUCTION 

A vegetation management study was established 

within a mixed loblolly pine (Pinus- L.)- 

hardwood stand in 1984. Almost all the pines in 

this stand appeared to have a very slow growth 

rate, even the larger sapling loblolly pine trees. It 

was concluded that interference from the hardwood 

trees and shrubs was the most likely reason for the 

slow diameter and height growth of these pine trees 

(Bacon and Zedaker 1987, Clason 1984, Glover and 

Dickens 1985, Waywosd 1986), and the severity of 

hardwood competition partly resulted from a series 

of management errors that often occur when 

regenerating lands to loblolly pine (Haywood 1988). 

Because several data sets were available from pure 

loblolly pine stands, a decision was made to examine differences in growth and yield associated 

with stand type. 

The purpose of our comparison was to determine if 

growth and yield differences existed among four independently established field studies. Differences 

would suggest that forest managers may have to accept a curtailment in pine growth and yield at the 

beginning of the rotation when managing mixed 

loblolly pine--hardwood in the West Gulf Coastal 

Plain, thus eliminating early commercial thinnings. 

DATA SELECTION AND PRESENTATION 

I n herent differences among sites, climate differences among growing seasons, and differences in 

genetic quality of the regeneration make it difficult 

to compare the case histories of independently established research studies. Our analysis was 

limited to plots established on silt loam soils in 

order to eliminate as many of these confounding 

factors as possible. Four data sets were used to 

'Research Forester, Southern Forest Experiment 

Station, Pineville, LA; and Project Leader, 

Southern Forest Experiment Station, Southern 

Hardwoods Laboratory, Stoneville, MS. 

represent a full range of stand types: two sites of 

pure loblolly pine planted on open-range maintained by fire and livestock grazing (Hawood 1983, 

1980), one site of pure loblolly pine that had become sucessfull y established despite interference 

from successional woody vegetation (Hawood and 

Burton 1989, Haywood and others 1981), and one 

site representing a mixed loblolly pine-hardwood 

stand (Haywood 1988). Mechanical site preparation had been carried out an all sites before 

regeneration. For all sites, stand age was 

referenced to the first growing season after site 

preparation because the exact age of individual 

trees in the mixed loblolly pine-hardwood stand was 

not known, and rotation length is an important 

economic consideration. Three of the four sites 

were located in Rapides Parish, Louisiana, and the 

fourth site was located in Drew County, Arkansas. 

All loblolly pines growing on a single site were 

similar in size and yield, so plot data were averaged 

for each of the four sites. Sampling age and tree 

size differed among sites, which precluded formal 

statistical analysis (Waistad and Kuch 1987). For 

each site, Schmitt and Bower's (1970) Formula was 

used to calculate the inside bark volume for each 

pine tree at least 4.5 ft tall. 

METHODS AND PROCEDURES 

Sites I and I1 

Sites I and II (pure loblolly pine) were located on a 

cutover longleaf pine (P. ill.) site in 

Rapides Parish, Louisian been maint en range. The growth of bluestem 

( pp.) had been favored by periodic 

burning and grazing. The woody plant csmponent 

consisted of small scattered s 

(Mvrica cerifera L.), post oak Wangenh.), and blackjack oak (4. 

Muenchh.). At Site I, the soils were Beauregard 
(Pfinthaquic Paleudult, fine-silty, siliceous, thermic) 

and Caddo flypic Glossaquaifs, fine-silty, siliceous, 

thermic) silt toams. At Site 11, the soils were Acadia 

(Aeric Ochraqualf, fine, montmorillonitic, t hermic), 

Beauregard, and Kolin (Glossaquic, Paleudalf, finesilty, siliceous, thermic) silt loams. The silt loam 

soils at both Sites I and II were moderately to highly 

productive for loblolly pine, with site indices of 85 to 

90 feet at 50 years (Kerr and others 1980). 

Prior to plot establishment, Site I was prescribe 

burned, and the woody vegetation was cut and 

removed at both sites. Site preparation treatments 

of harrow or harrow-bed were applied 6 months 

before planting at Site I and 4 to 6 months before 

planting at Site 11. Bare-root 1-0 loblolly pine seedlings were planted by hand at a 6- by 8-ft spacing 

in February 1962 at Site I and in February 1964 at 

Site II. Because hardwsod trees and shrubs were 

not a significant component of the vegetation 

during these studies, hardwood interference with 

the planted pine trees was considered minimal at 

both sites. 

Diameter at breast height (d.b.h.) and total height 

of lobiolly pine trees were measured 5, 10, and 13 

years after site preparation at Site I and 5, 10, and 

6 5 years after site preparation at Site II. Both the 

haraow-only and harrow-bedding treatments had 

similar loblolly pine tree growth and yield for each 

of the two sites. Therefore, the loblolly pine tree 

data from both treatments were combined before 

constructing the case histories for Sites I and 11. 

Site Ill (pure loblolly pine) was an upland hardwood 

sawtimber site in Drew County, Arkansas. Before 

logging, the dominant and codominant hardwoods 

were sweetgum ( L.), white 

.), water 

L.), and hickory (Carva spp.). The 

timber was elearcut in 1970 and 1971. After logging, the site averaged at least 500 hardwood 

stems 1 inch or larger in d.b.h. per acre, with a 

basal area of more than 20 ft2!ac before site 

preparation. The soils were Calloway (Glossaquic 

Fragiudalf, fine-silty, mixed thermic) and Henry 

(?"ypic Fragiaqualf, coarse-silty, mixed thermic) silt 

loams (barance and others 1976). These soils were 

moderately productive for loblolly pine trees with a 

site index of 80 ft at 50 years. 

Mechanical site preparation (chop-burn and shearburn) was carried out on the research plots the summer before planting in 1970. Bare-root 1-0 loblolly 

pine seedlings were planted by hand at a 6- by 8-8 

spacing that winter. Hardwood trees and shrubs 

numbered 3,860 stemsjac 3 years after site preparation, and brush intederence with the pine trees was 

considered severe on all plots f~r 7 years. 

However, 4 2 years afier site preparation, the pine 

trees had overtopped most hardwood competilors, 

and the brush was no longer an impo~ant poftisn 

of the basal area. Thus, hardwood intederence was 

considered unimpoi-tant 12 years after site preparation. 

The d. b. h. and height of loblolty pine trees viere 

measured 7 and 12 years after site preparation. 

During these measurements, the pine trees were 

each classed as either potential crop trees or suppressed trees. Potentiat crop trees were pines that 

should reach merchantable size, were free-to-grow 

or intermediate, and had at least a 10-percent 

chance of capturing a place in the crown canopy. 

Suppressed trees were pines that were overlopped 

by other woody plants, with iess than a 10-percent 

chance of capturing a place in the crown canopy. 

Loblolly pine trees from both the chsp-burn and 

shear-burn treatments had similar yields 1% years 

after site preparation, so the pine data from both 

treatments were combined to construct a case history for Site Ill. 

Site IV 

Site IV (mixed loblolly pine-hardwood) was in 

Rapides Parish, Louisiana. The soil type was a 

Beauregard silt loam with a site index oh 90 ft at 50 

years for loblolly pine. The previous forest stand 

had been clearcut, which was followed by a chop 

and burn site preparation in the summer sf 19"7". 

In February 1979, the tract was direchseeded from 

a helicopter at a rate of 1 IWac OF loblslly pine 

seeds. Conditions for direct seeding were good, 

but sufficient regeneration was not obtained. Ira 

February 1980, bare-root 1-0 lobisity pine seedlings 

were planted by hand into a tall grass cover at a 6- 

by 10-ft spacing. In December "1980, suwival of the 

planted pines was 29 percent but the site was considered 91 percent stocked (550 pine treesiac) 

when natural, d irect-seeded, and planted seedlings 

were combined. Six years af-rer site preparation, 

the planting rows were undistinguishabie, and the 

number of loblolly pines averaged "1,210 kree%,ac, 

which was well above 100 percent stocking. 

Six years after site preparation, hardwood trees at 

least 4.5 ft tali numbered 2,025 stemslac at Site tV 

Sweetgum, the most common hardwood, was In a 

mixture that consisted mainly of blackgum ( 

svlvatica Marsh ), 

southern red oak 

water oak, live oa 

oak. Shrubs nu 

rY ( spp.) was common (k600 canes!ae), as 

were several vines. 

The d. b. h. and height of pine and hardv~o~d trees 

were measured each year from the 6th through the 

9th year after site preparation. Each pine tree was 
classed as either a potential crop tree or a suppressed tree as at Site Ill. Data from the pine and 

hardwood trees were used to construct a case history for Site IV. 

RESULTS 

Volume growth of individual loblollg pine trees was 

very good on this cutover open range, although the 

total number of loblolly pines decreased by only 36 

treeslac from the 5th to 13th year after site preparation (table 1). Therefore, Site I was the most productive of the four sites based on the combination of 

good stocking and rapid growth of individual trees 

(flpure 1). Mean annual increment (m.a.i.) was 345 

ft fac from the 5th to 10th year and increased to 

372 ft3/ac between the 1 0th and 1 3t h year after site 

preparation. Total pine yield was 2,980 ft3/ac after 

13 years. 

Years After Site Preparation 

Figure 1 .--The total inside bark volume per acre for 

loblolly pine trees at each site. Sites I, II, and Ill 

were pure loblolly pine (PP), and Site IV was mixed 

loblolly pine-hardwood (MPHW). 

Table 1. Density and mean growth and yield of loblolly pine at 

least 4.5 ft tall on four sites in the West Gulf Coastal Plain. 

Years Average 

after site volume 

preparation Density d.b.h. Height per pine 

trees/ac inches - ft - ft3 

Site I' 

Site I1 

Site I11 

Site IV 

'sites It 11. and 111 were pure loblolly pine, and Site IV was 

mixed loblolly pine-hardwood. 
Site I1 

Individual loblolly pine tree growth was not as rapid 

at Site II, although the mortality rate was somewhat 

greater than at Site I (table 1). The m.a.i. was 210 

ft3!ac from the 5th to 10th year, but this decreased 

to 148 ft3iac between the 10t h and 15th year after 

site preparation Total pine yield was 1,873 ft3iac 

after 15 years (figure 1). 

The stocking of lobloily pine trees was good despite 

interference from hardwood trees and shrubs 

during the first 7 years after site preparation (table 

1). Once the pine trees were established, the 

growth rate increased, and the m.a.i. for all pine 

trees was 270 ft3/iac from the 7th to 12th year. It is 

evident from figure 1 that the m.a.i, was less than 

the 270 ft3/ac before the 7th year. Total pine yield 

was 1,641 ft3/ac after 12 years (figure 1). Of the 

three pure loblolly pine sites, this was the least 

productive 7 ysars after site preparation, but by 12 

years, Site Ill was producing more volume per acre 

than Site 11. 

Six percent of the loblolly pine trees were suppressed 7 years after site reparation; this com- !I? prised only 3 percent (8 ft lac) of the total yieid. 

After 12 years, 11 percent of the pines were suppressed because the canopy had closed, but suppressed trees still comprised 3 percent (49 ft3/ac) of 

the total yield. The potential crop trees yielded 290 

and 1,592 ft3/ac 7 and 12 years after site preparation, respectively (figure 2). 

The number of loblolly pines on this site increased 

by 324 trees/ac from the 6th to 9th year after site 

preparation, and the mean size of the pine trees 

was much smaller than at the other three sites 

(table 1). The increasing number of pine trees had 

a negative influence on mean d. b. h., height, and 

volume per tree, so the mean growth of these trees 

was very slow for the 3-year period. Nevertheless, 

the m.a.i. for all pine trees was 39 ft3iac between 

the 6th and 9th year after site preparation, and total 

pine yield was only 152 ft3/ac after 9 years. Clearly, 

the mixed loblolly pine-hardwood site was the least 

productive of the four sites for pines (figure 1). 

The actual number of potential loblolly pine crop 

trees remained constant over the 3-year period, 

with an average stocking of 632 treeslac, The number of suppressed pine trees increased from 101 to 

425 from the 6th to 9th year after site preparation, 

showing that although many new pine seedlings 

and saplings were developing, the majority, if not 

all, remained as suppressed trees. After 6 ysars, 14 

percent of the pine trees were suppressed, comprising 12 percent (4 ft3/ac) of the total volumeiac, but 

after 9 years, 41 percent of the pine trees were suppressed, comprising 18 percent (27 ft3iac) of the 

total volumelac. The potential crop trees yielded 31 

and 124 ft31ac 6 and 9 years after site preparation, 

respectively (figure 2). 

Both intraspecific and interspecific competition contributed to the low productivity of lobloll y pine trees 

at Site IV. The loblolly pine regeneration often 

Site Ill (PP) Site IV (MPHW) 

Years After Site Preparation 

Figure 2.--me inside bark volume per acre for Isblol- suppressed trees. Site Ill was pure loblolly pine 

ly pine trees at Sites Ill and lV by three classifica- (PP), and Site IV was mixed fobloliy pine-hardwood 

tions: all pine trees, potential crop trees, and (MPHW). 
Table 2. Density and mean growth of hardwood trees at least 4.5 

ft tall on Site IV, a mixed loblolly pine-hardwood stand, 

Years 

after site 

preparation Density d,b,h, Height 

stems/ae inches - ft 

formed clusters of pine trees. Consequently, the 

larger crop trees crowded or overtopped adjacent 

pines, and this slowed the diameter and height 

growth of the smaller trees. Conversely, because 

the intermediate or suppressed trees were growing 

so close to the larger pine trees, the diameter and 

height growth of the larger trees was also adversely 

affected. Interference from hardwood trees was 

also a factor. The number of hardwood trees at 

least 4.5 feet tall increased by 1 ,181 stemslac from 

the 6th to 9th year after site preparation, due largely 

to ingrowth, and the average d.b.h. and height of 

these hardwood trees increased 0.2 inches and 2.4 

ft, respectively, between the 6th and 9th years 

(table 2). There were also 1,559 hardwood treeslac 

less than 4.5 ft. tall and "9102 shrubslac after 9 years. 

DISCUSSION 

The successful development of planted loblolly pine 

trees on Sites I and I1 was probably due to quick establishment of the regeneration where herbaceous 

plants were the most common competitors. Timely 

pine regeneration was also established at Site Ill, 

and quick establishment permitted planted seedlings to stay abreast of competing hardwoods and 

to eventually overtop the brush. Once the brush 

was overtopped at Site ill, pine m.a.i. increased. 

Therefore, timely planting and successful establishment of seedlings after mechanical site preparation resulted in pure stands of lobloily pine trees 

without additional efforts to reduce competition 

from other species after planting. 

On the other hand, Site IV became a loblolly pinehardwood mixture primarily because the attempts 

at artificial regeneration by direct seeding and planting failed. This allowed the hardwood trees to gain 

a competitive advantage or equal status with the 

pine seedlings. The site was well-stocked with pine 

seedlings 2 years after site preparation because of 

natural loblolly pine regeneration. However, the 

pine trees at Site IV were clearly inferior in growth 

and yield to pine trees at the other three sites after a 

similar period of time. 

After the direct seeding failed, planting of seedlings 

without additional site preparation resuited in further failure and was a poor investment. Although 

the site eventually became stocked by natural 

regeneration, the delay from failure of the artificial 

regeneration resulted in a mixed loblolly pinehardwood stand. 

These results suggest that artificial regeneration 

must be established quickly after site preparation, 

otherwise it is likely that the stand will become a 

mixed lobloll y pine-hardwood stand. Such mixed 

stands result in curtailment of pine growth, and 

yield at the beginning of the rotation and early commercial thinnings may not be possible. 
LITERATURE CITED 

Bacon, C. G; Zedaker, S. M. 1987. Third-year 

growth response of loblolly pine to eight levels of 

competition control. Southern Journal of Applied 

Forestry 11 :91-95. 

Clason, T. R. 1984. Hardwood eradication improves 

productivity of thinned lobiolly pine stands. 

Southern Journal of Applied Forestry 8:194-197. 

Glover, G. R.; Dickens, D. R. 1985. Impact of competing vegetation on yield of the southern pines. 

Ga. For. Res. Pap. 59. Georgia Foresty Commission, Research Division. 14 p. 

Haywood, J. D. 1980. Planted pines do not respond 

to bedding on an Acadia-Beauregard-Kolin silt 

loam site. Res. Note SO-259. New Orleans, LA: 

U.S. Department of Agriculture, Forest Service, 

Southern Forest Experiment Station. 4 p. 

Haywood, J. D. 1983. Response of planted pines to 

site preparation on a Beauregard-Caddo soil. pp. 

14-17 In: Proceedings of the second biennial 

southern silvicultural research conference. 

Asheville, NC: U.S. Department of Agriculture, 

Forest Service, Southeastern Forest Experiment 

Station. 

Haywood, J. Q. 1986. Response of planted Pinus 

L. to brush control in northern Louisiana. 

Forest Ecology and Management 15:129-134. 

Haywood, J. D. 1988. Effects of prescribed burning 

or hexazinone as release treatments in a juvenile 

mixed loblolly pine-hardwood stand. Baton 

Rouge: Louisiana State University. 82 pp. PhD. 

Dissertation. 

Haywood, J. D.; Burton, J. D. 1989. Loblolly pine 

plantation development is influenced by site 

preparation and soils in the West Gulf Coastal 

Plain. Southern Journal of Applied Forestry 13: 17- 

21. 

Haywood, J. D.;Thill, R. E.; Burton, J. D. 1981. Intensive site preparation affects loblolly pine 

growth on upland sites. pp. 224-231. In: Proceedings of the American Society of Agricultural 

Engineers Symposium on Engineering Systems 

for Forest Regeneration. 

Kerr, A., Jr.; Griffis, B. J.; Powell, J. W. [and 

others]. 1980. Soil survey of Rapides Parish, 

Louisiana. Alexandria, LA: U.S. Department of 

Agriculture, Soil Conservation Service and Forest 

Service in cooperation the with Louisiana Agriculture Experiment Station, 86 pp. 

Larance, F. C.; Gill, H. V.; Fultz, C. L. 1976. Soil survey of Drew County, Arkansas. Little Rock, AR: 

U.S. Department of Agriculture, Soil Conservation 

Service in cooperation with the Arkansas Agriculture Experiment Station, 86 pp. 

Schmitt, D.; Bower, D. 1970. Volume tables for 

young loblolly, slash, and longleaf pines in plantations in south Mississippi. Res. Note 50-102. 

New Orleans, LA: U.S. Department of Agriculture, 

Forest Sewice, Southern Forest Experiment Station. 6 p. 

Walstad, J. D.; Kuch, P. J. 1987. Forest vegetation 

management for conifer production. John Wiley 

& Sons, New York, 523 p. 
EVENAGED MIXTURES OF CHERRYBARK OAK AND 

LOBLOLLY PINE IN SOUT ESTERN AWWMSAS 

Wayne I(. latterb buck' 

- M~xtures of cherrybark oak ar pagodlfoiia Eli ) and iobiolly pine (Pincls 

j were studled in southweste inor stream bonoms to determine rf these 

htghly vaiued species could be managed together rn even-aged stands The management sbject~ve was to have pine pulpwood and sawtrmber in short rotations and quality oak sawt~mber rn 

longer rotatrons Two of the three studied stands were 34-year loblolly plne plantations establlshed on old field sltes. Volunteer cherrybark oaks had rnvadad these old flelds a few years before 

pine plant~ng The thud stand was a naturally regenerated oak-pine m,xture over 100 years old 

S~te ~ndex for loblolly pine at all three sltes averaged 95 feet at 50 years Stem analyses showed 

that loblolly pine generally surpassed cherrybark oak In he~ght and diameter The few cherrybark 

oaks that were dominant were opsn-grown The oaks even though crowded and sometimes overtopped by plnes, persrsted In these stands, suggesting the p~ss~b~l~ty of an oak stand alter a plne 

harvest However, cherrybark oak form and bole quality were serrousiy cornprom~sed when grown 

adjacent to pine, Without ~ntermed~ate silvrcultufal treatments to promote oaks and/or to alter 

spaclngs mixtures of cherrybark oak and loblolly plne do not appear to be a fsas~ble alternative 

on the studled sites for the production of h~gh quality oak sawtlmber 

INTROBUCTION 

Mixed stands of oak-pine ( SPP.- 

spp.) exist on many Piedmont, Coastal Plain, and 

Interior Upland sites in the South. Most mixed 

stands are the accidental result of incomplete harvesting and site preparation, fire, or abandonment 

of farm land and pasture (Zahner 1982). However, 

such stands are often attractive alternatives to pure 

stands with regard to wildlife habitat (Sweeney 

1 980), aesthetics (McGee 1 984), and timber production (Phillips and Abercrombie 1987). The benefits 

of mixed oak-pine stands have been reviewed (Zahner 1982; Sims and others 1981 ), however little 

grovvth and management information is available. 

The development and silvicultural potentials of evenaged mixtures of cherrybark oak ( 

Ell.), a species hi 

loblolly pine (Pinu 

shonter rotation species grown primarily for sawtimber and fiber, are described in this paper. 

STUOV AREA 

Three even-aged stands containing mixtures of chearybark oak and loblolly pine were examined in 

southwestern Arkansas (Clark County). These 

stands were located on the lower side slopes and 

terraces of minor streams in the Coastal Plain. 

Characteristics of the stands are described below. 

Formerly Research Forester, U.S. Department 

of Agriculture Forest Sew~ce, Southern Forest Exper~ment Station, Sewanee, TN; Presently Staff 

Forester, Forest Resource Planning, Tennessee 

Drv~s~on of Forestry, Nashville, TN 

Stands 1 and 2 were 34-year-old loblolly pine plantations established on old field sites with existing cherrybark oak volunteers. Whether the fields were 

pasture or row cropped and abandoned several 

years before planting is unknown. The spacing of 

pines both between and within rows was variable, 

ranging from 6 to 42 feet. No tkinnings or cultural 

treatments have been done since planting. The 

stands are present1 y in the stand exclusion stage 

(Oliver 4981) with both loblolly pine and cherrybark 

oak in the dominant canopy. Oak species comprise 28 percent of the stand basal area. 

Site index for lohlolly pine (base age 50) in stands 1 

and 2 was estimated ta range from 82 to 87 feet 

(Hoelscher 1 987). However, direct measurements 

indicate that these stands are much more productive, with dominant pines averaging 90 feet of 

height in 34 years. Although no candidate trees 

were available For measurement, the site index for 

cherrybark oak was estimated to be 94 feet at 50 

years (Baker and Broadfoot 1939). 

Soiis of stand I are Gurdon silt loam (csarse-silty, 

siticeaus, thermie Aquic Paleudults) or Urba silty 

clay laam (fine, mixed, acid, thermic Aeric Waplaqueprs) (Hselscher 1989). Bath soils are deep, 

somewhat poorly drained, and occasionally 

flooded; they developed in silty to clayey alluvium 

on 1 - to 3-percent slopes. 

The soils of stand 2 are Wilcox silt loam (fine, 

monlmoritlonite, tkermic Vertic Hapluadalfs) 

(Hoefscker I 987). These soils are deep, somewhat 

poorly drained, and developed in clayey shale on 3- 

$8 8-percent slopes. 
Stand 3 is a natural mixed oak-pine stand that is 

over 100 years old. Stand origin is unknown, but it 

was probably an abandoned old field that naturally 

regenerated to both pine and oak. A heavy thinning occurred in the early 1940's. Dominant oaks 

averaged 20 inches in dbh (diameter breast height) 

and 100 feet in height, while dominant loblolly pines 

were 24 inches in d bh and 1 10 feet in height. The 

stand is in the understory reinitiation stage (Oliver 

1981 ), with loblolly pine and cherrybark oak comprising the dominant canopy. Understory vegetation includes hickories (Carva spp.), hollies (Ilex 

spp.), and hornbeam (Carpinus caroliniana Walt.). 

Oak species comprise 50 percent of the stand basal 

area. Soils are Gurdon silt loam (Hoelscher 1987), 

as previously described. Site index for stand 3 was 

similar to that of stands 1 and 2. 

PROCEDURES 

Ten plots were established in stands 1 and 2. Each 

plot contained a subject cherrybark oak as the plot 

center and included those trees interacting with it. 

An interacting tree was defined as any adjacent tree 

whose crown touched the crown of the subject tree 

or whose crown was above or below the edge of the 

subject tree crown (Smith and Lamson 1983). Plot 

size was, therefore, variable and irregular and 

ranged from 0.04 to 0.1 1 acre. The use of variable 

plot sizes with a subject tree as the plot center is 

common in studies of stand development (Oliver 

1982; Clatterbuck and Hodges 1988). Data from 

the 10 plots in stands 1 and 2 were pooled because 

these stands were similar in site quality and age. 

For a cherrybark oak to be selected as a subject 

tree, it had to be surrounded on three sides by 

loblolly pines. Subject trees were chosen from the 

dominant, intermediate, and suppressed crown classes. Codominant cherrybark oak trees were infrequent in these stands and were not sampled. The 

following data were recorded for all trees 4.0 inches 

in dbh on each plot: species, azimuth and distance 

of interacting trees from the cherrybark oak subject 

tree, crown class, diameter at 4.5 feet, total height, 

and log grade. 

Stem analysis was conducted on the 10 cherrybark 

oak subject trees and on 8 interacting loblolly pines 

for reconstruction of height and diameter growth 

patterns. All trees were sectioned at 0.5 foot above 

ground and at 4-foot intervals thereafter along the 

bole to the tallest centrally located growing tip. The 

number of annual rings of each section was subtracted from the total age to determine the age of 

the tree when its terminal leader was at or near the 

height of each section. Heights were plotted over 

the corresponding ages to illustrate the height 

growth pattern of each tree. Diameter growth at 4.5 

feet was determined by measuring the annual increment along four perpendicular radii. Height and 

diameter data were analyzed using normal stand 

reconstruction procedures (Oliver 1982). Only 

mean height and diameter relationships are 

presented in this report, because the small sample 

size does not allow an adequate statistical test. 

In stand 3, two dominant cherrybark oak plots were 

established similar to those described for stands 1 

and 2. Stem analysis was not attempted on these 

older, large diameter trees. Increment cores were 

taken at 4.5 feet on each cherrybark oak subject 

tree and on an interacting dominant loblolly pine on 

each plot to determine age-diameter relationships. 

RESULTS 

The cherrybark oaks in stands 1 and 2 were volunteers that were 3 to 10 years older than the planted 

loblolly pines. Because they were older, the oaks 

had an initial height advantage over loblolly pines 

(figure 1). At the time of pine planting, the existing 

cherrybark oaks were already 18, 9, and 3 feet tall 

for dominant, intermediate and suppressed crown 

classes, respectively. However, the loblolly pines 

surpassed intermediate and suppressed oaks in 

height 10 years after planting and surpassed 

dominant oaks after 25 years. Diameter growth patterns (figure 2) are similar to the height growth patterns for dominant pines and intermediate and 

suppressed oaks. Dominant cherrybark oaks have 

maintained approximately a 4-inch diameter advantage over lobloliy pines. 

Year Distance (feet) 

Figure 1. - A.--Mean height growth patterns of 

dominant (DO), intermediate (10) and suppressed 

(SO) cherrybark oaks and associated dominant 

loblolly pines (DP). 

B.-- Approximate distance of dominant, intermediate, and suppressed cherrybark oaks from 

competing dominant pines. 
Year 

Figure 2.--Mean diameter (dbh) growth patterns of 

dominant (DO), intermediate (10) and suppressed 

(SO) cherrybark oaks and associated dominant 

loblolly pines (DP). 

The size and crown class of each of the cherrybark 

oak subject trees in stands 1 and 2 appear to be related to both the distance to the nearest interacting 

dominant or codominant loblolly pine and the age 

difference between the pine and the oak. For example, oaks became dominant only if they were 8 

or more years older than the planted pines and at 

least 15 feet away from an interacting dominant 

pine. With increasing distance and age difference 

between the two species, there is a progressive increase in the size of cherrybark oak trees (figure 1 ). 

The irregular spacing and the small sample size in 

this study make it difficult to predict height and 

diameter growth of cherrybark oaks at varying distances from the pines. 

Diameter growth patterns of oaks and pines in 

stand 3 (figure 3) indicate that the oaks were 

released in a partial cutting in the early 1940's. The 

two subject cherrybark oaks were 5 inches in dbh 

and 55 years old at the time of release and presently are 20 inches in dbh and 100 years old. The 

dominant loblolly pines have maintained a fairly 

steady rate of diameter growth at 2.7 inches per 

decade. In comparison, the cherrybark oaks 

averaged 3.5 inches per decade after release. 

Even though height growth of cherrybark oak was 

not documented by stem analysis in stand 3, the 

height where the terminal leader resumed height 

growth after release from suppression may be 

deduced from the presence of crooks and forks on 

the dominant oak stems. For the subject trees, this 

height was 42 feet. The height growth pattern for 

these cherrybark oaks most likely resembles the 

suppression and release pattern shown in figure 3. 

Year 

Figure 3.--Diameter growth (dbh) patterns of two 

dominant loblolly pines (DP1 and DP2) and two 

dominant cherrybark oaks (DO1 and 002) from 

stand 3. There was a partial cut of loblolly pines in 

the early 1940's. 

DISCUSSION 

Pattern of Development 

When cherrybark oaks grow in mixed stands with 

iobioliy pines on these minor stream bottom sites in 

southwestern Arkansas, the pines eventually become taller than the oaks, even when the oaks are a 

few years older. Loblolly pines have a faster initial 

rate of height growth than cherrybark oaks, and the 

pines maintain this faster rate longer. As the pines 

increase their height advantage, they progressively 

influence and suppress more distant oaks. Thus 

the greater height growth rate of loblolly pines more 

than compensates for the initial height advantage of 

older oaks. 

The only dominant cherrybark oaks on these sites 

were those that were approximately 8 or more years 

older than the planted pines, and had no pines 

growing adjacent to them. It is not known whether 

the growth advantage of these oaks resulted in the 

suppression and death of adjacent planted pines or 

if pines had not been planted close to these established oaks. The dominant oaks developed the attributes of open-grown trees: large crown volumes 

and short branch-free boles. Although pines will 

eventually be taller, the oaks will have larger 

diameters because they are older andlor their large 

crown volumes promote greater diameter growth. 

Even though the pines are younger than adjacent 

oaks, their height and diameter growth patterns do 

not appear to be affected by the older oaks. For 

the first 34 years, height and diameter growth of 

dominant loblolly pines is almost linear. If pine 

coverage is adequate, pines will dominate the 
stand. Oaks dominate in those areas where they 

did not compete with pines. Removal of competing 

pines by thinning would be necessary to promote 

the retention and subsequent deveiopment of the 

oak component in these mixed stands. 

Data from this study suggest several s~tviculrural approaches for the establishment and management of 

loblolly pine and cherrybark oak miaures. The fast 

initial height groMh sf pines and the slower overall 

growth of oaks indicate that these species should 

be widely spaced to keep oaks from becoming suppressed. Wide spacings would concentrate gro\(vth 

on the crop trees because the groWt7 wouid not be 

restricted by adjacent trees. AIthoug h the rotation 

length for oak sawlogs would be shofler, there 

would probably be no intermediate hawests or income, and available growing space would be underutilized early in the rotation. Rotations of 35 to 40 

years under this even-aged unrestricted management approach would yield dominant cherrybark 

oaks and loblolly pines with average dbk-r's of 16 inches (figure 2). The unrestricted approach 

resembles the 'free gromh" technique, which has 

been used successfully with green pruning on oak 

stands in Great Britain to obtain high grade butt 

logs in a short time (Jobling and Pearce 1977). 

If cherrybark oak and ioblsily pine are closely 

spaced, the pines will eventually ovefiop and suppress the oaks. At leasmone thinning would be required to remove competing pines and favor oak 

growth. Distance to competing pines depends on 

when the thinning takes place, the size of competing pines that are removed, and whether more thinnings are planned. With close spacings, a 

two-stage system of timber harvest is possible In 

mixed oak-pine stands. The fast growing lobisily 

pine could be harvested in thinnings as puipwssd 

and small sawlsgs, thus providing an intermediate 

income. The slower growing oaks would constitute 

the final hamest. This two-stage system is practiced 

1 974). 

Without siivicultural treatment to enhance the 

grovvth of cherrybark oak, most dominants will be 

iobfolf y pine. Oaks will either remain underneath 

pines in a suppressed condition or die. "i"hese oaks 

may respond to release if the averstory pines are 

hamested, as exhibited in stand 3. However, research with released cherrybark oaks after 5 years 

in east-central Mississippi suggested that intermediate and suppressed cherrybark oak trees are 

not good candidates far crop trees because of variable performance when refeased and because of 

reduced bole quality due to epicormic branches 

(Meadows 1988) 

Cherrybark oak requires strong lateral shading to 

develop long, straight, branch-free boles. The wide 

spacings requlred for cherrybark oak and loblolly 

pine mixtures on these minor stream boMoms 

promote cherrybark oak crown expansion at an earlier age and, therefore, shorter clear bole lengths. 

bower branches are retained for a longer time, 

promoting larger branch diameters and making it 

more difficult for branch scars to heal once 

branches are shed, thus reducing log grade. Cherrybark oak log quality will improve somewhat with 

increased stem diameter: however, these logs will always have a core with large knots. 

The height to th first live branch of dominant oaks 

in stands 1 and 2 averaged 25 feet, with many large 

surdace knots and dead branch stubs on the lower 

bole. Additionat clear bole length is diminished because of the retention of the large diameter lower 

branches. This reduced clear bole length is in contrast to cherrybark oak-sweetgum ( 

I.) stands, where sweetgum trees 

nger cherrybark oak clear bole lengths 

(to 50 feet), smaller branch diameters. and better 

log quality (Clafierbuck and Hodges 1988). Sweetgum acts as a "trainer" species that will naturally differentiate to crown strata below the oaks. There is 

no silvicultural reason to differentially harvest the 

sweetgum, In contrast, IobSslly pine is a "cornr to American sycamore 

I.) (Clatterbuck and others 

1987), that competes vigorously with the oak crop 

trees 

A series of pine thinnings, if critically applied, could 

somewhat mimic conditions produced by trainer 

species. However, cherrybark oak under this 

scenario probably would not aMain the exceptional 

bole quality associated with those grown with "true" 

trainer species. 

SUMMARY 

Cherrybark oak can be managed in mixtures with 

loblolly pine on minor stream bottom sites if initial 

spacings are wide or thinnings are planned to 

progressively hawest pines before the oaks become 

severely suppressed. Cherrybark oak requires 

ample growing space to develop, and because pine 

has a faster rate of height growth, pine tends to 

oveflop and dominate the slower growing oaks at 

close spacings. Cherrybark oaks that were 

daminant had been open grown and had large 

crowns and short bole lengths. The paMern of 

stand development found on these sites may differ 

from other areas, depending on the physiology of 

the interacting species, their relative ages, the site, 

regeneration origin (seeds, sprouts, or advanced 

regeneration), initial spacing, and the age a% the 

starad components. 
ACKNOWLEDGEMENTS 

This research was initiated under the auspices of 

The Ross Foundation of Arkadelphia, AR. 

Manuscript was written while the author was 

employed by the USDA Forest Service. The author 

is grateful to Dr Chadwick Dearing Oliver, University 

of Washington, Seattle, and Mr. E. C. Burkhardt of 

Vicksburg, MS, for their field and data assistance 

and reviews of the manuscript. Appreciation is also 

expressed to Dr. Charles E. McGee, Dr. Glendon W. 

Smalley, Dr. Michael G. Shelton, and Mr. Robin P. 

Bible for manuscript reviews. 

LITERATURE CITED 

Baker, James B.; Broadfoot, W. M. 1979. Site 

evaluation for commercially important southern 

hardwoods. Gen. Tech. Rep. SO-26. New Orleans, LA: U.S. Department of Agriculture, Forest 

Service, Southern Forest Experiment Station. 

51 p. 

Clatterbuck, Wayne K.; Hodges, John D. 1988. 

Development of cherrybark oak and sweetgum in 

mixed, even-aged bottomland stands in central 

Mississippi, U.S.A. Canadian Journal of Forest 

Research 18(1): 12-1 8. 

Clatterbuck, W. K.; Oliver, C. D.; Burkhardt, E. C. 

1987. The silvicultural potential of mixed stands 

of cherrybark oak and American sycamore: spacing is the key. Southern Journal of Applied 

Forestry 1 1 (3): 1 58-1 61 . 

Hoelscher, James E. 1987. Soil survey of Clark and 

Hot Spring Counties, Arkansas. U.S. Department 

of Agriculture, Soil Conservation Service, 

Washington, DC. 264 p. 

Jobling, J.; Pearce, M. L. 1977. Free growth of oak. 

Forest Record No. 1 13, Forestry Commission. 

London: Her Majesty's Stationery Office. 17 p. 

McGee, Charles. 1984. Conflict and progress in 

hardwood management. Forest Farmer 43(9):23- 

25. 

Meadows, James Steven. 1988. Response of suppressed cherrybark oak and green ash trees to 

release from overstory competition. Mississippi 

State: Mississippi State University. 191 p. Dissertation. 

Oliver, Chadwick Dearing. 1981. Forest development in North America following major 

disturbances. Forest Ecology and Management 

3: 153-1 68. 

Oliver, Chadwick Dearing. 1982. Stand development--its uses and methods of study. p. 100-1 12. 

In: Means, Joseph E., ed. Forest succession and 

stand development research in the Pacific 

Northwest; 1981 March 26; Corvallis, OR. Corvallis: Forest Research Laboratory, Oregon State 

University. 

Penistan, M. J. 1974. Growing oak. p. 98-1 12. In: 

Morris, M. G.; Pering, F. H., eds. The British oak, 

its history and natural history. Cambridge: 

Pendragon Press. 

Phillips, Douglas R.; Abercrombie, James A,, Jr. 

1987. Pine-hardwood mixtures--a new concept in 

regeneration. Southern Journal of Applied 

Forestry 1 1 (4): 192-1 97. 

Sims, Daniel H.; McGee, Charles E.; Gallaway, 

Jerry [and others]. 1981. Mixed pine-hardwood 

stands--low-cost option for reforestation. Forest 

Farmer 40(10):10-11 ,I 6-1 7. 

Smith, H. Clay; Camssn, Neil 1. 1983. Precommercia1 crop-tree release increases diameter growth 

of Appalachian hardwood saplings. Res. Pap. 

NE-534. Broomall, PA: U.S. Department of 

Agriculture, Forest Service, Northeastern Forest 

Experiment Station. 7 p. 

Sweeney, James M. 1980. Wildlife habitat management in Mid-South upland hardwoods. p. 144- 

151. In: Proceedings, Mid-South upland 

hardwood symposium for the practicing forester 

and land manager; 1980 April 30-May 2; Harrison, AR. Tech. Publ. SA-TP-12. Atlanta, GA: 

U.S. Department of Agriculture, Forest Service, 

Southeastern Area, State and Private Forestry. 

Zahner, Robert. 1982. Some benefits of establishing planted pine-natural hardwood mixtures. 

p. 13-23. In: Haymond, Jacqueline L., coord. 

Cost-effective regeneration practices, proceedings of the second annual forestry forum; 1982 

March 16; Clemson, SC. Clemson: Clemson 

University Cooperative Extension Service and 

Department of Forestry. 

WILDLIFE 

Moderator: 

David C. Guynn, Jr. 

Department of Forestry 

Clemson University 

WILDLIFE HABITAT QUALITY IN VARYING MIXTURES OF 

PINE AND NTARDWrnD 

T. Bently Wigley, R. Larry Willett, Michael E. Garner, and James B. ~aker' 

-Five treatments, each replrcated 3 times were randomly assigned to fifBeen O 25 ha 

pine-hardwood stand on the Grossen Experimental Forest near Crossetl, AR Treatments 

cons~sted of mrxtures of 100, 90, 80, 70, and 50 percent pine ! ~pp i growing stock with cornpiementai-y propodions of hardwoods ,4211 plots were thinned to 15 rnC ha basal area in I983 Ffom 

1983 through 1985 annual production of totai forage woody plants legumes vines, and forbs 

did not differ by treatment Afier hardwood regeneratfan was krlled ~r: 1985 annual productton of 

ground-level vegetation ( 5 m) was generally greater on the 1196 percent plne plats than on the 

pine-hardwood mixtures Forage produclron typl ol diNer among the prne-hardwood mtxtures during any year Acorn producl~on per oak ( spp ) tree was not drfferent among treatments In 1988, percent cover of ground-level and shrub (1 5-5 rn) layers was greatest in the 100 

percent pine plots Cover of mldst~ry 15-10 m) and canopy (10 rn) layers was greatest in the 50 

and 70 percent plne plots favor~ng wildltfe spectes dependent on these layers 

INTRODUCTION 

Pine-hardwood forests are an important source of 

wildlife habitat in the United States, particularly in 

the South. About 40 percent of the nation's commercial forests are in the southern U.S and an estimated 15 percent of these 73.7 million ha are 

officially designated as mixed pine-hardwood 

stands (25 to 50 percent pine) (USDA Forest Service 1988). Yet, many upland southern forests have 

both pines and hardwoods present. In addition to 

providing wildlife habitat, these 'forests aNord opportunities for recreational activities such as hunting, 

fishing, birdwatching, hiking, camping, and picnicki ng . 

About 70 percent of the South's forests are owned 

by private, nonindustrial landowners (USDA Forest 

Service 1988), Although timber production is ofien 

the most important reason nonindustrial private 

landowners own forests (Porterfield and others 

1978, Nabi and others 1983), most nonindustrial 

forest landowners have multiple-use ownership 

goals, with wildlife uses ranking high (Nabi and 

others 1983, Owen and others 1985). Multiple-use 

goals are reflected in the preference that rnany 

private, nonindustrial landowners have far pinehardwood mixtures (Nabi and others 1983). Many 

publicly owned pine-hardwood forests are also 

managed for multiple resource values. For rnany 

landowners then, it is important to balance timber 

and wildlife values of pine-hardwood forests. 

Although numerous studies have examined wildlife 

habitat in pine-hardwood stands (Schuster and 

'~ssoclate Professor, Deparlment of Forest 

Resources University of kkansas Monticeiio Extension Forester Un~verslty of Arkansas Monlicello, Research Spectallst University of Arkansas 

Mont~ceilo, and Project leader Southern Forest 

Exper~ment Slat~on Montrcelio AR 

Halls 1963; Halls and Schuster 1965; Blair 1971 ; 

Blair and Brunett 1988; Htrrst and others 1979; Fenwood and others If384), there are few data evaluating habitat quality in stands with varying 

proportions of pine and hardwood. The objective of 

this study was to compare wildlife habitat quality in 

stands having a range ol pine and hardwood compositions. 

METHODS 

The study area is located on the CrosseM Experimental Forest near Crossen, AR. Using a cornpletely randomized design, 3 replications of 5 

treatments were assigned to 15 8.25-ha plots in a 

pine-hardwood stand. The stand is on a terrace adjacent to a small stream, and has a 50-year site 

index of about 30 rn for I 

Loblolfy and shortleaf (P. 

dominant in the canopy and hardwoods were 

generally subordina"ee. 

Treatments were 100, 90, 80, 70, and 50 percent 

merchantable (9 cm dbh) pine growing stock with 

complementary proportions of hardwoods (0, 10, 

20, 30, and 58 percent) Merchantable-sia trees on 

all plots were thinned to about 15 m2iha BA during 

July 1983. In selecting hardwood trees to be left, 

oaks ( spp.) were favored, and red oaks 

were favored 2 to 1 over white oaks. Many 

hardwarad stems that were prod merchantable-sized 

at the beginning sf the study had become merchantable-sized by summer 1985, Therefore, during late 

summer 1985, hardwood trees in the 90, 80, 70, 

and 50 percent pine plots that were 2.5 cm dbh, but 

not marked as study trees, were killed by injecting 

with Roundup herbicide. The 188 percent pine 

plots were treated with ground-applied belparg herbicide. 
Annually from 1983-1 988, timber and wildlife habitat 

variables were measured on the interior 0.1 ha portion of each plot. Data were not collected on the 

100 percent pine treatments during 1984 because 

of timber hawesting. The dbh of each tree was 

measured during fall or winter. Acorns were collected from oak trees 23 cm dbh from 1 September 

through 1 December using a bushel basket with a 

0.15m2 opening was placed on the north side of 

each tree midway between the bole and the edge of 

the crown. During August, percent cover of groundlevel (.5 m) vegetative species was estimated using 

12 1 -m2 subplots located on a grid in each 0.1 ha 

plot. Current-year growth (CYG) of woody plants, 

legumes, vines, grasses, forbs (including ferns and 

composites), and mushrooms was clipped on the 

subplots, oven-dried at 105 degrees C and weighed. 

During August 1988, percent cover of ground-level, 

shrub (1.5-5 m), and midstory (5-10 m) layers were 

estimated at 30 sample points in each plot using 

0.25m2, 2-m2, and 4-m2 subplots, respectively. Percent cover of the canopy (10 m) was estimated by 

taking 30 observations at each sample point with a 

spherical densiometer (Lemmon 1956). The percent 

cover of the ground, shrub, midstory, and canopy 

layers was used to calculate foliage height diversity 

(FHD) (MacArthur and MacArthur 1961) using the 

formula Hi = -1: pi In pl , where pi = the proportion 

of cover in each layer. 

One-way and two-way analysis of variance (with 

treatment and year as main effects) were used to 

evaluate differences in measured variables (Norusis 

1988). Duncan's New Multiple Range Test was used 

to separate means. Analysis of covariance, with tree 

dbh as a covariate, was used to evaluate acorn 

production by treatment and year Contingency 

table analysis and the chi-square statistic was used 

to evaluate associations between number of plant 

species, treatment, and year. Statistical significance 

was accepted at the 0.05 probability level. 

RESULTS 

During 1983, pines on the study plots averaged 42 

cm dbh; hardwoods averaged about 25 cm dbh 

(table 1). By 1988, pines were about 46 cm dbh and 

hardwoods were about 27 cm dbh. Average dbh of 

pines and hardwoods did not differ by treatment 

during any year (p > 0.05). Tree growth on the plots 

is more fully described by Murphy and others 

(1 989). 

d-level veat ion 

In each year of the study. the importance of individual ground-level species varied by treatment. 

However, the number of species categorized as 

woody, graminoid, legume, forb, and vine did not 

differ between treatments during any year 

Table 1. Average stand characteristics for treatments after 

timber harvest in 1983 and 1988. 

Percent pine basal area 

Stand 

characteris tic lo0 90 80 70 50 

------------------ 1983 ----------------- Pine no. trees/ha 98.5 108.5 63.6 74.8 41.2 

dbh (cm) 46.6 39.1 47.8 45.5 48.5 

basal area m2/ha) 16.5 14.4 12.9 11.3 8.0 

Hardwood no. treeslha 3.7 71.1 78.6 116.0 205.8 

dbh (cm) 3.1 21.4 24.9 24.9 22.3 

basal area (m2/ha) (0.1 2.9 4.5 5.9 8.5 

Pine no. trees/ha 89.8 104.8 63.6 74.8 41.2 

dbh (cm) 49.5 42.0 51.1 48.5 51.1 

basalarea(m2/ha) 17.3 16.1 14.5 12.9 8.9 

Hardwood no. trees/ha 3.7 71.1 78.6 116.0 187.1 

dbh (cm) 3.7 24.0 27.5 28.1 25.2 

basal area (m2/ha) (0.1 3.7 5.4 7.3 9.9 

Table 2. Average percent cover of ground-level (<1.5m) vegetative 

species over all treatments. 1983-1988. 

Year 

Plant species1 1983 1984 1985 1986 1987 1988 

Woodv Plants 

Acer rubrum 

Callicarpa americana 

-- Cornus f lorida 

Liquidambar straciflua 

Nyssa sylvatica 

Pinus spp. 

-- Quercus alba 

Q. falcata 

Q. nigra 9. phellos 

Quercus spp. 

-- Ulmus alata 

Vaccinium spp. 

Graminoids 

Chasmanthium sessiliflora 2.5 3.7 13.6 13.0 9.0 8.9 

Panicum spp. 2.3 0.5 3.0 6.1 5.4 2.5 

Vines 

Ampelopsis arborea 0.4 0.5 0.4 0.4 0.2 0.3 

-- Berchemia scandens 1.6 0.9 1.0 0.9 1.4 1.0 

Gelsemium sempervirens 0.6 0.2 0.3 0.4 0.9 1.1 

-- Lonicera japonica 0.6 0.3 0.3 0.2 0.2 0.2 

Parthenocissus 

quinquefolia 

-- Rhus radicans 

Rubus spp. 

Smilax spp. 

Vitis spp. 

Forbs 

Elephan to= spp. 0.6 0.2 0.3 0.5 0.4 0.7 

Erichtites hieracifolia (0.1 0.3 0.4 1.5 0.4 0.4 

Mentha spicata 0.1 0.0 0.1 0.5 0.6 0.4 

Mitchella repens 1.9 0.7 0.7 0.4 0.8 1.1 

Includes only species with cover exceeding 0.5 percent during 

at least one year. 
Table 3. Average percent ground cpver of ground-level species 

differing by treatment, 1983-1988 . 

Percent pine basal area 

Species 100 90 80 70 50 

Acer rubrum l.7ab2 2.9b 2.9b 0.6a 2.2ab 

Berchemia scandens 0.8a 4.2b l.la 0.8a 0.8a 

Cal licarpa americana 2.8b O.la 0.38 O.la O.la 

~hasmanthium sessiliflora 4.6b 0.3a 2.3ab 0.4a 4. 6b 

Cratae s spp. O.Oa 0.7ab 0.8b O.Oa O.1ab 

&lsem% sempervirens O.Oa 1.3~ 0.8bc 0.7abc 0. lab 

Onoclea sensibilis 0.4b O.Oa O.Oa O.Oa O.Oa 

Panicurn spp. 2.la 4.4b 1.4a 2.2a l.5a 

Sanicula canadensis 1.0b 0.3a 0.4ab O.0a 0.4ab 

spp. 7.4b 1.3a 3.6ab 1.9a 4.2ab 

Callicarpa americana 

Crataems marshallii 

Elephantopus spp. 

Gelsemiurn sempervirens 

Panicum spp. spp. Sassafras albidum 

Callicarpa americana 

Erichtites hieracifolia 

Calactia spp. 

Celsemium sempervirens 

Oxalis spp. 

Panicum spp. 

Pinus spp. 

Rhus radicans 

Vaccinium spp. 

Acer - rubrum 

-- Berchemia -- - -- scandens 

Boehmaria spp. 

Callicarpa americana 

Cassia spp. 

Cornus f lorida 

Elephantopus spp. 

Gelsemium sempervirens 

Hamamelis virginiana 

Lespedeza spp. Mentha spicata 

Mitchella repens 

Panicum spp. 

Parthenocissus 

guinquefolia 

Pinus spp. 

Vaccinium spp. 

Zanthoxylem spp. 

Berchemia scandens 

Boehmaria spp. 

Callicarpa americana 

Cassia spp. 

Elephantopus spp. 

Erichtites hieracifolia 

Calium spp. Gelsemium sempervirens 

Hamamelis virginiana 

Hypricum spp. 

Mitchella repens 

Osmnnthus spp. 

Oxalis spp. Panicum spp, 

Quercus phellos 

Quercus spp. 

-- Rhus radicans 

Rubus spp. 

Vitis spp. 

---- 

4.8b 

O.Oa 

0.7b 

0.8b 

2. la 

1. gbc 

0.8b 

---- 

8.5b 

6.0b 

0.4b 

1.5b 

0.4b 

16.0b 

3.9b 

2.6b 

4.9b 

---- 

0,7bra. 

0.4a 

0. Oa 2.5b 

0.2b 

1.5b 

0.8b 

1. lab 

0. Oa 0.3b 

O.2ab 

0.5a 

10.6b 

0.4a 

7,ib 

2.8b 

0. la 

----. 

0.2a 

0. Oa 

2.6b 

0.4b 

1.2~ 

0.7ab 

0.3b 

1.7b 

0. Oa 

0.2b 

0.8ab 

0.2b 

0.9b 

4.8b 

0. Oa 

O.Oa 

3.4~ 

5 9b 

2.8b 

1.9~ 

O.Oa 

0.6a 

O.la 

l.lbc 

0.9b 

0. lab 

1.7b 

0. Oa 

O.Oa 

1.5bc 

O.Oa 

0.3a 

2.9ab 

0.7b 

1.8b 

2.3bc 

2.3a 

1.6ab 

0.8ab 

O.Oa 

0.4a 

O.Oa 

0.4ab 

0.48 

0. lab 

0.5a 

1.3b 

O.Oa 

1. labc 

O.Oa 

0. la 

0.6a 

0.3ab 

0.08 

1.3ab 

0.9, 

1.6ab 

'Ground cover did not differ for any species during 1984. 

(p > 0.05). The number of ground-level species identified on each treatment also did not differ by year 

(X2 = 5.7, 16 df, p = 0.991). 

During 1983, 46 species were identified on the 

study plots. In generai, ground-levei vegetation was 

dominated by greenbriars (Smilax spp.), poison ivy 

( ), blueberry spp.), and 

grape (Vitis spp.) (table 2). Ground cover of 10 

spe 

bea 

fern 

area in the 100 percent pine plots than in the pinehardwood mixtures. Cover of 8 s~ecies differed . .

among the pine-hardwood mixtuies. Rattan (E3er- 

~hemia scandens), panic grass (Panicum spp.) and 

yellow jessamine (Gelsemium sem~ervirens) had 

greatest cover in the 90 percent pine plots. For the 

other 5 species there was no consistent pattern of 

differences among pine-hardwood treatments. 

Although percent cover of individual species differed among treatments, production of total forage, 

woody plants, vines, legumes, forbs, fungi, and 

graminoids did not differ by treatment during 1983 

(table 4). In general, production of total forage, 

woody plants, and graminoids was lower during 

1983 than during other years. Legume production 

did not differ by treatment (p = 0.143) or year (p = 

0.702), and averaged 0.7 kg/ha. Mushroom production was also not different by treatment (p = 0.839) 

or year (p = 0.367), and averaged 0.4 kg/ha. Mushrooms were found only on the 90, 80, and 50 percent pine plots and were found only during 1983 

and 1987. 

During 1984, after the plots were thinned, only 38 

ground-level species were found. Greenbriars, Chasurn sessiliflora, grapes, and pines had 

greatest ground cover over all treatments (table 2). 

However, no ground-level species differed in cover 

between treatments. CYG of woody plants, vines, 

forbs, and graminoids also did not differ by treatment (table 4). Forb production was not different 

from production in 1983 (p<0.01). CYG of woody 

plants, graminoids, and vines, and total forage, 

however, was greater than during 1983 (p< 0.05). 

In 1985, graminoids, greenbriars, grapes, and 

blueberry dominated the plots (table 2). Over all 

treatments, was the most 

important g sing 4-fold 

from 1984. Greenbriars doubled in cover compared 

to 1984. Although the number of species increased 

to 56, cover of only 7 differed among treatments 

(table 3). Cover of American beautyberry was 

greater in the 100 percent pine plots than in the 

pine-hardwood mixtures. Panic grasses were most 

rcent pine plots. Hawthorn 

was more abundant in the 80 

'~eans with different letters within rows are different. 
percent pine plots than in other treatments. Production of total forage. woody plants. vines. forbs. 

graminoids, and legumes again did not diMer by 

treatment (p < 0.05) (table 4). During 1985, G"r" oof 

total forage, woody plants, graminoids, and vines 

was greater than during 1984 (p < 0.05). Production 

of vines peaked during 1985. 

Table 4. Average dry weight (kgiha) of current-year growth for 

ground-level ((1.5 a) vegetation, 1983-19a. 

Percent pine bmal area 

Type of Vegetation 1OO '30 80 70 50 

W~Y 

Legumes 

Graminoids 

Forbs 

Vines 

-gi 

Total 

W~Y 

Legumes 

Graminoids 

Forbs 

Vines 

Total 

woody 

Legumes 

Graminoids 

Forbs 

Vines 

Total 

woody 

Legumes 

Graminoids 

Forbs 

Vines 

Total 

W~Y 

Legumes 

Graminoids 

Forbs 

Vines 

W&i 

Total 

Woody 

Lepes 

ermineids 

Forbs 

Vines 

Total 

'pleans with different letters within rows are different. 

In 1986, following the injection and Velpar application, the number of species decreased to 49. In 

the dominant ground-level species. Cover of 9 

species diNered by treatment but no species differed in percent cover among the pine-hardwood 

(QxAk spp.), and yellow jessamine was greater on 

tt-re 100 percent pine plots than on the pinehardwood mixtures. CYG of total forage, woody 

plants, graminoids, forbs, and vines was also 

greater on the 100 percent pine plots than on the 

pine-hardwood mixtures (p < 0.05) (table 4). Forage 

production, however, did not differ among the pinehardwood mixtures. CYG of total forage, woody 

plant, graminoids, and forbs peaked during 1986. 

During 1987, graminoids, pines, and vines such as 

greenbriar, blackberry ( spp.), grape, poison 

ivy, and rattan were dominant in terms of ground 

cover (table 2). Ground cover of 17 of the 62 

species differed among treatments (table 3). Pergreatest on the 100 percent pine plots. Cover of 

only 6 species differed among the pine-hardwood 

mixtures. Ground cover of rattan, partridgeberry 

(Mitchella repens), Virginia creeper ( 

nd toot hache-tree 

re greater on the 9 

ots than on plots with less pine basal 

area Coverage of witch-hazel (Hamamelis vir- 

), and false netter on the 50 

percent or 70 percent pine plots than on treatments 

with greater pine BA. CYG of total forage and 

woody plants was greater on the 100 percent pine 

plots than on the pine-hardwood mixtures (p < 

0.05) (table 4); graminoid, forb, and vine production did not differ by treatment. Forage production 

did not diMer among the pine-hardwood mixtures. 

Over all treatments, production of total, woody, 

forb, vine, and graminoid forage was lower than 

during 1986. 

During 1988, , greenbriar, 

pine, blackberry, panic grass, and blueberry were 

mast prominent (table 2). Percent ground cover for 

19 of 67 species differed by treatment (table 2). 

Cover For 7 of the 19 species was greatest on the 

100 percent or 90 percent pine plots. Witch-hazel 

was the only species with greatest cover in the 50 

percent pine treatment. Production of total forage 

and woody plants was greater on the 100 percent 
pine plots than on the pine-hardwood mixtures (p< 

0.05) (table 4). CYG did not differ among the pinehardwood mixtures for any forage category. 

Graminoid, forb, and total CYG was less, but vine 

production was greater, than during 1987. Forage 

production in 1988 was, in general, not different 

from production during 1984. 

FHD during 1988 was greater in the 100 percent 

pine plots than in the pine-hardwood mixtures (p == 

0.003) (table 5); FHD values did not differ among 

the pine-hardwood treatments. During 1988, 

ground cover was greater on the 100 percent pine 

treatment than on any of the pine-hardwood mixtures (p < 0.001 ). Ground cover also was greater on 

the 90 percent pine plot than on the 50 percent pine 

plot. Shrub cover was greatest on the 100 percent 

pine plots, but did not differ among the pinehardwood mixtures (p < 0.001). The 100 and 80 percent pine plots had the least amount of midstory 

cover; midstory cover was greatest in the 50 and 70 

percent pine treatments (p< 0.001). Cover of the 

canopy layer was greatest in the 50 percent pine 

treatment and least in the 100 and 80 percent pine 

treatments (p< 0.001). 

Table 5. Foliage height diversity (FHD) and percent cover of forest 

layers by treatment, 1988. 

Percent pine basal area 

Forest Layer 100 90 80 70 50 

Percent cover: 

Ground (c1.5 m) 44.6c1 32.2b 31.9b 26.0ab 23.8a 

Shrub (1.5-5 m) 47.6b 21.2a 30.9a 21.7a 28.8a 

Midstory (5-10 m) O.Oa 5.9bc 3.8ab 11.0~ 9.5~ 

Canopy 010 m) 79.6a 85.9b 78.7a 86.6b 91.5~ FHD o.67b 0.55a 0.58a 0.56a 0.55a 

'~eans with different letters within rows are different. 

Acorn nrnduction 

Acorn production per basket did not differ among 

treatments, but was different by year (p = 0.002). 

Production during 1983, 1984, 1985, and 1986 was 

2, 1, 9, and 7 kgiha, respectively. Acorn production 

during 1983 and 1984 was lower than production 

during 1985 and 1986. Because of poor mast crops, 

too few acorns were collected during fall 1987 and 

1988 to conduct analyses. 

DISCUSSION 

In general, the quality of habitat for white-tailed deer 

(Odocoileus virginianus) and other species dependent on ground-level vegetation did not differ between the pine-hardwood mixtures. After hardwood 

regeneration was killed, however, production and 

cover of preferred forage species was greater on 

the 100 percent pine plots than on the pinehardwood mixtures. 

These results are consistent with other studies relating ground-level production to overstory and 

midstory characteristics. Understory production is 

typically inversely related to BA and the number of 

forest layers (Halis and Schuster 1965, Blair 1967, 

Blair and Enghardt 1976, Wiggers and others 1978, 

Hurst and others, 1979). In most southern forests, a 

dense multilayered midstory of hardwoods most inhibits forage growth (Schuster and Halls 1963, Blair 

1969, Blair and Enghardt 1976, Blair and Feduccia 

1977). A dense hardwood midstory may also cause 

undesirable changes in forage production by 

decreasing total number of species, the number of 

palatable species, and plant vigor (Schuster and 

Halls 1963, Blair 1967). 

The FHD values suggest that, even with no 

midstory, the 100 percent pine plots offered the 

best habitat for songbirds. The high FHD value for 

the 100 percent pine was largely attributable to the 

high degree of cover in the ground and shrub 

layers. This vegetation, however, was pines, 

American beautyberry, and blackberry that were of 

sufficient height to be tallied in the shrub layer. This 

habitat would favor bird species more typically 

found in pine plantations than in pine-hardwood 

stands. Southern pine is most valuable for birds 

when mixed with hardwoods (Myers and Johnson 

1978, Briggs and others 1982). The number of 

horizontal strata and development sf the midstory 

and canopy is positively correlated with bird 

species diversity (MacArthur and MacArthur 1961, 

Myers and Johnson 1978). 

For wildlife species dependent on acorn production, habitat quality was best in the treatments with 

the greatest BA in oaks. Acorn production per tree, 

however, did not differ among treatments, suggesting that growing conditions for oaks was similar 

across treatments. At BA 15m2/ha, differences in 

acorn production might occur. 

CONCLUSIONS 

Generally, habitat quality did not differ among the 

pine-hardwood mixtures. Even 10 percent of BA in 

hardwoods, however, reduced forage production 

below levels in plots with 100 percent of BA in pine. 

For landowners seeking to favor wildlife, 50 percent 

of BA in pine provided forage production not different from the 90 percent pine plots. Additionally, 

on the 50 percent pine plots, acorn production and 

midstory development was greater than on the 90 

percent or 100 percent pine plots. It should be 

noted, of course, that this study only evaluated 

habitat quality in stands with 15 m2/ha BA. Further 

research is warranted to evaluate habitat in pinehardwood stands with higher BA's. 
ACKNOWLEDGMENTS 

We thank Mike Chain and Mike Sutton for their help 

with field work. James M. Guldin, Ron E. Thill, and 

Lynne C. Thompson provided editorial assistance. 

Derik J. Reed helped with data analysis. This study 

was funded by the U.S. Forest Service, Southern 

Forest Experiment Station. 

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of Agriculture, Forest Service Resource Rept. No. 

24. 512pp. 

Wiggers, Ernie P.; RobineMe, 0. Lamar; Sweeney, 

John R, [and others]. 1978. Predictability of deer 

forages using overstory measurements. Proceedings Annual Conference Southeastern 

Association Fish and Wildlife Agencies 32: 

187-1 94. 
WILD TURKEY ACTIVlTlES IN REtaTlON TO TIMBER WPES 

ON THE FRANCIS MARION NATIONAL FOREST 

Hugh R. Stilt, Jr. and David P. ~aumann' 

-F~fty-five wtld turkey ( hens and 20 gobblers 

were trapped, equipped with telemetry packages and released on stte durrng 1981 -84 

Movements were mon~tored throughout the pertod to determine nesting hab6tat and 

eneral habitat prefe Il seasons The bald cypress j &.k 

water tupelo ( ) timber type was the most preferred habttat type 

for both gobblers and hens Turkey hens preferred regenerated forest ( 10 years) and 

mtxed pineihardwood stands for nest~ng 

INTRODUCTION 

A telemetry study of the nesting ecology and habitat 

utilization of an established population of eastern 

wild turkeys was conducted during 1981 -84. We 

sought to determine the relationship of nesting with 

timber type and various stand characteristics. 

Preferred habitat types were to be identified for 

both sexes during all seasons. 

This research project was part of an intensive effort 

to investigate the dynamics of a population that has 

been noted as one of the purest strains of eastern 

wild turkey. This population was the source for the 

s~~ccessfu1 restoration of wild turkey in the Pledmont and mountain areas of South Carolina. 

METHODS AND MATERIALS 

The study area was the Waterhorn Hunt Unit (H.U.) 

and sections of the adjacent Northampton H.U. of 

the Francis Marion National Forest. Also included 

were in-holdings owned by timber companies or 

private individuals. The study area totals 18,940 ha 

in Berkeley and Charleston counties near Clellanville, South Carolina. 

The Waterhorn H.U. is significant historically in that 

it was set aside by presidential proclamation as a 

wild turkey refuge in 1948 (Wolbrook 1952). A hogproof fence was constructed around 6,883 ha during the early 1950's and the area was managed 

intensively for wild turkeys to provide birds for restocking. During 1952, project personnel estimated 

a population of 800 to 980 birds on the refuge 

(Hot brook 1 952). 

Principal forest types on the study area included 

pine and swamp hardwood. The primary pine 

'~ss~stanl District Blolog~st South Carolina 

Wildlife and Marine Resources Department, Clemson, SC; State Turkey Btologrst, South Carolina 

\Nildiifi% and Martne Resources Department. Bonneau SC. 

species on the study area were loblolly (Pinu 

and longleaf (El. . During the study 

period, 3,901 ha (21 percent) of the study area were 

typed as longleaf and 6,747 ha (36%) as loblolly (excluding regeneration areas). Pineihardwood or 

hardwoodlpine (mixed stands) comprised only 765 

ha (4 percent). A high percentage of the older timber stands on the study area was comprised of the 

bald cypresslwater tupelo (BCLWT) timber type 

which was often flooded. Silvicultural practices on 

the area included clearcutting and planting or seed 

tree cutting with natural regeneration for pine 

stands. Natural regeneration of hardwood sites occurred after clearcutting. Prescribed burning was 

common in the upland pine types. A tidal stream 

ran through the middle of the study area and many 

dikes and ditches associated with early rice culture 

were present. 

The study area had a number of Forest Sewice 

roads which included approximately 61.3 km of 

rock surfaced road, 41.5 km of logging roads, 27.0 

km of improved ditched dirt roads and 14.8 km of 

paved road. Many of the logging roads provide access to the 142 wildlife openings present on the 

study area. 

Turkeys were captured by rocket-projected netting 

as described by Austin (1965) and Dill (5969) on 

sites baited with shelled corn during the months of 

January, February, and early March in 1981 -84, 

Captured birds were weighed, aged, banded, and 

fitted with a solar- or battery-powered transmitter. 

Transmitters were attached to birds using harnesses of nylon-covered rubber tubing. A motion 

sensing feature of the transmitters allowed interpretation of animal activity. 
Birds were located at various times of the day at 

least 3 times a week. In addition, gobblers were 

monitored at 2-hour intewals at least 1 day a week 

to obtain representative daily activity patterns. On 

these days, readings began prior to birds leaving 

the roost each morning and continued until all birds 

flew to roost in the evening. Locations of turkeys 

were determined as described by Cochran and 

Lord (1 973). Habitat utilization was analyzed using 

a modified TELEM program (Koeln 1980). A 

digitized computer map prepared by Wesniaco Corporation from U. S. Forest Service compartment 

maps, aerial photographs and USGS maps was 

used to determine habitat types and preferences. 

All seasonal habitat utilization fixes were combined. 

Habitat use data were combined for all birds since 

the same habitat types were used by adult and 

juvenile birds. Dates were recorded when the transmitter activity sensor attached to hens indicated 

periods of inactivity and radio locations became 

clustered signifying nesting activity. 

Initially, nest sites were located by flushing hens 

from nests. Since birds abandoned their nests after 

being flushed this method was terminated. Subsequently, nests were circled and flagged while the 

hen was on the nest, then located when the hen 

was away. 

After hatching occurred, data collected at each nest 

site included adjacent understory and overstory 

vegetation, basal area and proximity to ditches and 

skid trails. Preferences of turkeys for different age 

and type timber stands were analyzed using 

met hods derived by Neu and others (1 974). 

Standard U. S. Forest Service cover type guidelines 

were used to determine the timber composition of 

the area surrounding the nest and for each timber 

stand type on the study area. Stands in which 70 

percent or more of the crowns in the dominant and 

codominant position were either softwoods or 

hardwoods were classified as a pure stand. Stands 

in which 51-69 percent of the crowns in the 

dominant and codominant positions were either 

hardwood or pines were classified as a mixed 

stand. While Forest Service type maps, prescriptions, etc. were used for habitat preference, actual 

overstory measurements were taken surrounding 

turkey nests. Therefore a nest located in a small 

patch of pineihardwood type within a larger pure 

pine stand would be classified as having a mixed 

overstory. 

RESULTS 

Nestina Habitat 

During the 4 years of the study, 37 turkey nests 

were located and evaluated. Of these, 28 were 

nests of study hens while 9 noninstrumented birds 

were located by U. S. Forest Service personnel 

during routine duties or by hunters. Of the 37 

nests, 1 5 (40%) occurred in mixed stands, 1 1 (30%) 

occurred in areas of pine overstory, and 10 (27%) 

occurred in clearcuts ten years old or younger or 

seed tree cuts (table 1). One nest was found in a 

young pine stand (13 years old) which had been 

destroyed by wildfire. Nests often occurred in small 

mixed patches within larger stands that were typed 

as pine, or near stand edges or transition zones 

where mixed types were more prevalent. Basal 

area measurements for mixed and pine species surrounding nest sites averaged 8.73 and 6.59 square 

meters, respectively. 

Stand type was significantly associated (p r 0.10) 

with the occurrence of nesting sites (table 1). Hens 

preferred regenerated stands ( r 10 years) and 

mixed stands while avoiding pure pine and pure 

hardwood stands. 

Stand age was also significantly associated (p I 10) 

with the occurrence of nesting sites (table 2). One 

nest occurred on private land where the age of the 

overstory was unknown and one nest was located 

in a stand that had been destroyed by wildfire. 

Table 1.--Composition of overstory vegetation surrounding turkey nests on the Francis Marion National Forest, SC 

( 1981-84) 

Proportion Confidence 

Proportion Number of Fkpec ted observed interval on 

Overs tory Total of total nests in number in each proportion of 

tY Pe hectares area area observed area occurrence 90% ~esults~ 

Pine 10,919 0.577 I I 2 1 0.297 0.122(pi(0.472 A 

Hardwood 4 , 979 0.263 0 10 0.000 - ipi( - A 

Regenerat icn 

j 10 years ) 1,261 0.066 10 2 0.270 0 . lOO<pi<O -440 P 

Mixed 765 0.040 15 2 0.405 0.217(pi(0.593 P 

Other 1,016 0.054 1 2 0.028 0,000~pi~0.091 R 

Total 18, $40 37 37 
Table 2, Age class of overstory surrounding nests 

Confidence interval 

Proportion on proportion of 

Nmber Expected no. observed occurrence (9% 

Age of of nests in each confidence 

S~RSC: He nests (proportion) age class coefficient) 

Preferred 

Random 

Rmdsm 

Random 

Avoided 

Thirty-Five of the nests were located on U. S. Forest 

Service property where all stand age data were 

available. The statistical analysis was limited to 

these areas for the purpose of preference selection 

in table 2. Stands in the 0-10-year age class were 

preferred for nesting while stands greater than 70 

years were avoided. Stands in other age classes 

were selected randomly with no statistical indication 

of preference or avoidance. 

comprised of several timber types which included 

preferred the regenerated area (s "1 years). Hens 

-swamp tupelo-red maple ( 

Gobblers avoided loblotly, randomly selected 

longieaf and p he slash (e. and 

pond pine (e. categary an CW 

Stand type was significant1 y associated (p r 0.1 0) habitat type. The other hardwood and regenerated 

with habitat utilization by both hens and gobblers areas were randomly selected while the sweetgum- 

(tables 3 and 4). Wens preferred the BCWT and water oak-willow oak and sweet bay-swamp tupeloother hardwood categories. Other hardwoods were red maple timber types were avoided. 

Table 3.--Habitat preferences by wild turkey hens on the Francis Marion National Forest (1981-84) 

Proportion Confidence 

Proportion Number of Expected observed interval on 

Timber of total observations number in each psowrtion of 

type Area (ha f area in area observed area occurrence 90% ~esul tsa 

-- 

LoblolLy 

Longleaf 

Other pine 

Mixed 

Bald cypresswater tupelo 

Sweet g-t~nrwater oakwillow o& 

Sweet bayswmp tupelored maple 

Other hardwoods 

(primarily oaks) 

Wegene~ated areas Other 
Table 4.--Habitat preferences by wild turkey gobblers on the Francis Marion National Forest (1981-84) 

Proportion Gonfidznce 

Proportion Numberof Expected observed interval on 

Timber of total observations number in each proportion of 

type Area(ha) area in area observed area occurrence 90% ~esul tsa 

Loblolly 

Longleaf 

Other pine 

Mixed 

Bald cypresswater tupelo 

Sweet gumwater oakwillow oak 

Sweet bay - swamp tupelored maple 

Other hardwoods 

(primarily oaks) 

Regenerated areas 

Other 

Total 

DISCUSSION 

In thls study nesting hens did not tolerate human 

disturbance. Only 1 hen of 8 (1 1 O/O) returned to her 

nest after being flushed. Williams and others (1971) 

reported that 7 of 11 (64 percent) hens abandoned 

their nests after being flushed from their nests by investigators. Bidwell and others (1 985) reported that 

most nest losses (61 percent, 8 of 13) in his study 

area were due to human disturbance. As turkey 

hunters and other resource users increase on the 

Francis Marion, the disturbance and abandonment 

of nests could affect turkey reproduction markedly. 

The study suggests a need for mixed stand management for turkey nesting. Forty percent of the nests 

were located in areas where the overstory vegetation was mixed. These stands, however, comprised 

only 4 percent of the study area indicating a 

preference for nesting in mixed stands. 

Turkeys also preferred clearcuts between the ages 

of 0-10 years and seed tree cuts for nesting. They 

avoided the older age classes (> 70 years) which 

were often flooded. Hens also preferred low to 

moderately stocked stands for nesting as evidenced 

by basal area measurements around the nest sites. 

The preference of the BCWT type by hens and gobblers indicated the birds preferred a mature, undisturbed environment. The BCWT type generally was 

not harvested and provided an area relatively free 

of human activities, other than hunting. The 

majority of the BCWT timber type was found in a 

continuous strip along a tidal creek which bisected 

the study area. Turkeys often used this habitat type 

for roosting and made visits into other habitat types 

during the day. Ecotones appeared to be preferred 

as most turkeys were located only a short distance 

from the edge of the habitat type. The BCWT timber type has not been previously referenced as a 

preferred timber type for wild turkeys. 

Other hardwoods, primarily mast producing oaks, 

and regenerated stands were preferred by hens 

and randomly selected by gobblers. Timber 

management prescriptions should allow for the interspersion of mast producing oaks within small 

regeneration areas. 

ACKNOWLEDGEMENTS 

We wish to thank the following individuals for help 

in turkey capture, field obsewations, and for helpful 

suggestions: W. D. Shattuck, D. D. Adams, W. E. 

Mahan, P. K. Swiderek, F. G. Best, K. D. Dennis, T. 

T. Fendley, D. C. Guynn, S. W. Stokes, T. Swayngham, 0. Stewart, L. B. McDowell, R. Dunlap, M. J. 

Clise and D. Carlson. The project was funded jointly by the U, S. Forest Service and the South 

Carolina Wildlife and Marine Resources Department. 
LITERATURE CITED 

Austin, David H. 1965. Trapping turkeys in Florida 

with the cannon net. IN: Proceedings of the 

Southeastern Association of Game and Fish Commissioners. 19: 16-22. 

Bidweli, Terrance G.; Shalaway, Scott D.; 

Maugham, 0. Eugene. 1985. Nesting habitat and 

nest success of the Eastern Wild Turkey in 

Southeastern Oklahoma. IN: Wild Turkey Habitat 

Studies in Oklahoma. W-137-R-3. pp. 34-48. 

Cochran, William W.; Rexford, W. Lord. 1963. A 

radio tracking system for wild animals. IN: Journal of Wildlife Management. 27:9-24. 

Dill, Herbert H. 1969. A field guide to cannon net 

trapping. U.S. Department of Interior, Bureau of 

Sport Fisheries and Wildlife. 18 pp. (memeo). 

Holbrook, Herman L. 1952. The Francis Marion 

turkey project. IN: Proceedings of the 

Southeastern Association of Game and Fish Commissioners. 6:567-574. 

Koeln, Gregory T. 1980. A computer technique for 

analyzing radio telemetry data. IN: National Wild 

Turkey Symposium. 4:262-271. 

Neu, Clyde W.; Byers, C. Randall; Peek, James M. 

1974. A technique for analysis of utilizationavailability data. Journal of Wildlife Management. 

38(3) 1541 -545. 

Williams, Lovett E., Austin, David H.; Peoples, Tommie E.; Phillips, Robert W. 1971. Laying data and 

nesting behavior of wild turkeys. IN: Proceedings 

of the Southeastern Association of Game and 

Fish Commissioners. 25:90-106. 
THE FOX SQUIRREL (SCIURUS NIGER) IN 

SOUTHEASTERN PINE-HARDWOOD FORESTS 

Susan C. Loeb and Michael R. ~ennartz' 

. -Southeastern fox squirrels have experienced significant declines in their distribution 

and numbers over the past 100 years. Their decline has been attributed to the decline and fragmentation of the mature pine-oak forests on which they depend. Thus, an understanding of the 

habitat relations of southeastern fox squirrels is necessary to manage and conserve these animals 

rn the Southeast. We review what is presently known about I j the habitat relations (species composition, habitat structure, and landscape aspects) of fox squirrels in the Southeast, 2) the food 

habits, nesting habits, and movement patterns of fox squirrels, and 3) how the resource requirements relate to fox squirrel habitat selection. Future research needs are also outlined. 

1INIRODUC"II"ON 

Southeastern fox squirrels are the largest tree squirrels found in North America, ranging from 900 to 

1200 g in weight. This group is comprised of 5 subspecies: ciaereus which is found on 

the Belmarva peninsula, S. n. &,gx whose range includes North Carolina, South Carolina, most of 

Georgia, and the panhandle of Florida, S. n. sherwhich is found in the central portion of 

Florida, S. n. which is found on the 

southern tip of Florida, and S. n. bachmanl which is 

found primarily in Alabama and Mississipi (Hall 

1981 j. Southeastern fox squirrels are larger than 

midwestern fox squirrels (600 to 900 g) and more 

highly variable in color. The habitat associations of 

southeastern fox squirrels are also distinct. Unlike 

midwestern fox squirrels which are usually associated with open hardwood forests, often in small 

isolated woodlots and fencerows adjacent to agricultural fields (Flyger and Gates 1982), southeastern 

fox squirrels are usually associated with mature 

pine forests with an oak midstory. The longleaf 

pine-turkey oak (Pinus @aluSus-Quercus laevis) 

forests of the Coastal Plain and Sandhills Regions 

are considered the typical habitat of southeastern 

fox squirrels (Moore 1957; Weigl and others 1989) 

but, the loblolly pine (El. taeda) forests of the Piedmont Region may also provide good habitat. 

of Florida and is under consideration by the U. S. 

Fish and Wildlife Service for federal status (John 

Wooding, pers. comm.). The Big Cypress fox squirrel (S. n. Ncennia is also considered threatened 

by the state of Florida. The status of S. n. niger and 

S_n. bachmani is unknown, but Weigl and others 

(1 989) and Wood (1 988) suggested that the numbers of S. n. niaer in N~rt~Carolina and South 

Carolina are declining and measures should be 

taken to manage and preserve suitable habitat to 

prevent further decline. 

Knowledge of the habitat relations of any wildlife 

species is essential to effective management. Unfortunately, until recently southeastern fox squirrels 

have received very little study. The objectives of 

this paper are to review what is presently known 

about the habitat relations and resource requirements of southeastern fox squirrels and to outline 

what further knowledge is necessary before effective management of this species can be developed 

and implemented. 

HABITAT ASSOCIATIONS OF SOUTHEASTERN 

FOX SQUIRRELS 

The description of optimal habitat for any wildlife 

species should encompass at least three aspects: 

1 ) the species composition of the habitat, 2) the 

structure of the habitat, and 3) landscape dimensions, including the juxtaposition of various habitat 

types. Fox squirrel habitat relations have been examined, to varying degrees, at all three of these 

levels. Use of nest-boxes and, particularly, radiotelemetry have been the most commonly used 

methods for investigating habitat relations of the fox 

squirrel. 

Fox squirrels in the Southeast have experienced significant declines in their distributions and population numbers during the past century (Hamilton 

1943; MacClintock 1970; Seton 1953). The Delmarva fox squirrel (S. a. ' ) is a federally listed 

endangered species (U. S. Department 

1970) and Sherman's fox squirrel (S. n. 

is considered to be of special concern by the state 

%@search Eeologist/Mammaiogist, Southeastern Forest 

Exper~ment Station, Clemson, SC; Project Leader, 

Southeastern Forest Experiment Station, Clemson, SC. 

142 

Fox squirrel habitats in the Southeast usually contain both pines and hardwoods. Based on percent 
of radio-telemetry locations (Weigl and others 

1989), fox squirrels in the Sandhills of North 

Carolina spend the majority of their time in pine-oak 

habitats (between 58 percent and 77 percent 

depending on sex and season), followed by edge 

habitats (22 percent to 40 percent), bottomland 

hardwoods (1 percent to 7 percent), and field and 

oak-scrub habitats (0 to 3 percent). Fox squirrels 

also use more nest boxes in longleaf pine-oak 

habitats. However, nest boxes in both longleaf pineoak habitats and bottomland hardwoods are used 

in proportion to their availability. 

In the Coastal Plain of Georgia fox squirrels spend 

the majority of their time in loblolly pine-oak 

habitats (66.0 percent), followed by loblolly pine 

pole (7 to 10 m tall) habitats which have virtually no 

oaks (1 5.3 percent), bottomland hardwoods (1 1.3 

percent), longleaf pine-oak (5.2 percent), slash pine 

(fl. elliotti[) plantations (0.7 percent), and other 

habitats (1.5 percent) including old cuts, old fields, 

grass fields, food plots, and new cuts (Hilliard 

1 979). However, based on utilization versus 

availability, fox squirrels prefer loblolly pine-oak 

habitats (utilization/availability = 1 '66) and bottomland hardwoods (1.71) and avoid the slash pine 

plantation (0.15) and other habitats (0.05). Loblolly 

pine pole and longleaf pine-oak habitats are used in 

proportion to availability (0.96 and 0.95, respectively) and thus, are neither preferred nor avoided. 

Loblolly pine-oak habitats are also used the most 

often for nesting (69.8 percent of nest locations) followed by loblolly pine pole (13.2 percent), bottomland hardwoods (9.4 percent), and longleaf 

pine-oak habitats (7.6 percent). In the case of nests 

however, loblolly pine-oak, bottomland hardwoods, 

and longleaf pine-oak habitats are all preferred (U/A 

= 1.76, 1.42, and 1.38, respectively) whereas the 

squirrels tend to avoid loblolly pine pole habitats for 

nesting (UIA = 0.83). 

Edwards (1 986) studied fox squirrels in an area 

characterized by stands of longleaf and loblolly 

pine stands bisected by narrow hardwood drains 

and cypress (Taxodiums64a..) and gum (Nyssa 

a.) swamps in the Coastal Plain of South 

Carolina. In this area, fox squirrels prefer carolina 

bay habitats, pine-hardwood stands, and drains of 

hardwood and mixed species composition. Marshes and areas containing pure pine in the overstory but at low densities are avoided. Hardwood 

runners are used most often for nesting (36 percent) followed by pine-hardwood habitats (21 percent), low density pine habitats (15 percent), mixed 

runners (1 4 percent), cypress (6 percent), medium 

density pine habitats (4 percent), and carolina bay 

(4 percent). However, 90 percent of the nests are 

within 60 m of a habitat boundary and are most 

often adjacent to low and medium density pine 

habitats. 

Thus, studies using radio-telemetry to assess the 

amount of time spent in broad habitat categories 

(e.g., pine-hardwood vs. hardwood) indicate that 

pine-hardwood mixtures are important to 

southeastern fox squirrels. Using a different approach, Taylor (1 973) and Dueser and others 

(1 988) found that species composition had little to 

do with habitat suitability for Delmarva fox squirrels. 

These researchers compared sites with Delmarva 

fox squirrels to those where fox squirrels were absent but gray squirrels (S. carolinensis) were 

present. Areas that support fox squirrels have 

greater basal areas of American beech (Wgrandifolia) and mixed hardwoods but do not differ significantly from areas that do not support fox 

squirrels in terms of loblolly pine, oak, or hickory 

(Wsggr.) basal areas. When multivariate statistics are applied to these data, species composition 

shows only a marginally significant difference between sites that support fox squirrels and those that 

do not, and only 19 percent of the variation in fox 

squirrel presence or absence is explained by 

species composition. 

Habitat Structure 

Habitat structure has often been suggested as a 

critical component in fax squirrel habitat selecti~n 

in the Southeast. The density of the understory 

may be one of the most important factors. On the 

Delmawa peninsula, sites containing fox squirrels 

have an average understory cover of 29.7 percent 

whereas sites containing gray squirrels but not fox 

squirrels have an average understory cover of 71.5 

percent (Taylor 1973). Suitable habitats for Delmarva fox squirrels also have a greater percentage of 

trees 30 cm dbh or greater, a greater percentage of 

overstory cover, and less percentage shrub-ground 

cover, ('Taylor 1 973; Dueser and others 1 988). 

Taylor (1973) suggests that the apparent association of Delmarva fox squirrels with mature loblolly 

pine forests is due to the scarcity of understory 

growth in these stands and not to a reliance of fox 

squirrels on the pines themselves. Weigl and others 

(1 989) also found that fox squirrels prefer to use 

nestboxes in open, mature, longleaf pine stands 

with little understory. The importance of mature 

pine stands with a sparse understory for fox squirrels was suggested by other researchers (Hilliard 

1979; Kantola 1986; Moore 1957), but no data have 

been presented to support this conclusion. 

Landscape aspects of southeastern fox squirrel 

habitat relations have only been directly examined 

by Dueser and others (1988). Sites with fox squirrels do not differ significantly from sites without fox 

squirrels in terms of woodlot area, area of open 
fields, percentage of forested area, forest edge, or 

forest shape. t-lowever, woodlots with fox squirrels 

are closer to the nearest woodlot than sites without 

fox squirrels. Thus, the degree of isolation may be 

an important aspect of fox squirrel habitat selection. 

Although specific landscape variables have not 

been tested in other studies of fox squirrel habitat 

use same conclusions about landscape dimensions have been made by various researchers 

based on paaerns sf habitat use. These studies 

have ail found that edge or ecotonal areas may be 

significant to fox squirrels. Edwards (1 986) concluded that ecotones are very important to fox squirreis in the Coastal Plain of South Carolina based on 

both the high number of nests and the high number 

of telemetry locations outside of nests which are 

within 30 to 60 m of habitat boundaries. Kantola 

(1986) also found more nests in ecotonal areas (4.7 

nestsiha) than in upiand longleaf pine stands (2.7 

nestsiha). The ecotonal areas are downslope from 

uplands and are characterized by longleaf pines 

and turkey oaks interspersed with a variety of other 

oak species such as sand post oak (Q. stellab), live 

, and 

whereas the upland 

slopes have low productivity with longleaf pine and 

turkey oak being the predominant species. Kantoia 

(1986) suggests that greater use of ecotones by fox 

squirrels may be due to a greater diversity of mast 

producing oaks, a higher mast production within 

the ecotone areas, and more material, particularly 

Spanish moss, for nest insulation. Weigl and others 

(1 989) suggest that edge or ecotone habitats may 

be of importance seasonally. They describe a pattern of land use that is centered on the pine-oak 

forests with periodic shiRs to the moister, cooler 

areas of edge (transition areas between the longleaf 

pine-oak habitats and the bottomland hardwoods) 

and bottomland hardwoods, particularly in summer. 

RESOURCE REQUIREMENTS 

To fully understand the habitat relations of fox squirrels, knowledge of t heir resource requirements is 

needed, i.e., what resources and in what amounts 

need to be contained in the habitat. The food 

habits, nesting habits, and movement patterns, including escape from predators, are three critical 

components of fox squirrel suwival and are directly 

related to all three habitat dimensions. 

No quantitative data on the food habits of the fox 

squirrel have been published to date, However, 

based on observations of feeding and examination 

of some stomach contents, the diets of fox squirrels 

appear to be quite broad (Ha 1983; Moore 1957; 

Weigl and others 1989). Food items in the diets of 

southeastern fox squirrels include the mast from a 

large variety of trees, pine buds, staminate cones, 

berries, hypogeous and epigeous fungi, insects, 

and longleaf pine seeds. Some of the important 

species in the diet of southeastern fox squirreis are 

Turkey oak acorns and longteaf pine seeds appear 

to be of particular importance, at least in the Coastal Plain and Sandhills Regions (Ha 1983; Kantola 

1986; Moore 1957; Weigl and others 1988). Acorns 

are the major food items of southeastern fox squirrels during the fall, winter, and early spring. Further, reproduction of fox squirrels in the Southeast 

appears to be closely tied to the abundance of the 

fall mast crop (Kantola 1986; Weigl and others 

1989) as it is in many other species of tree squirrels 

(see Gurnell 1983 for review). Thus, the fall mast 

crop provides an important source of energy and 

nutrients for both maintenance and production. Because the turkey oak is the most dominant oak in 

the Sandhills and Coastal Plain Regions, it has been 

assumed to be the most important. However, in 

areas where turkey oaks are not available (e.g., the 

Piedmont Region), other oaks probably take their 

place. 

Longleaf pine cones are available for only a short 

period of time (1 to 3 months) but may still be a critical food source for fox squirrels in the Coastal Plain 

and Sandhills Regions. During late spring and 

early summer food supplies are very poor (Ha 

1983; Moore 1957; Weigi and others 1989). Acorns 

from the previous fall have ail been taken and few insects, buds, or flowers are available during this hot, 

dry period; squirrels often lose weight during this 

period and are in poor condition (Kantola 1986; 

Weigl and others 1989). This period of poor food 

supply ends with the ripening of the longleaf pine 

cones. Squirrels feed almost entirely on these - 

seeds for approximately one to two months (Moore 

1957; Weigl and others 1989). Each cone contains 

a large number of seeds (up to 150) and each seed 

has a very high energy content weigi and others 

1989), Thus, longleaf pine cones may be significant 

to fox squirrels in being the major source of energy 

during an othewise nutritionally stressful period. In 

the Piedmont Region of Georgia, loblolly pine cone 

seeds are also eaten during late summer (pers. 

obs.) but their importance relative to other foods is 

not known. 
NesXs water oak (Q. , wiltow oak (Q. red 

Fox squirrels utilize both cavities and outside leaf 

nests or "drays" for nesting (MacClintock 1970). 

However, in the Southeast, the frequency of cavity 

use is very low. In Georgia and Florida, only 7 percent of all nests utilized by fox squirrels are in 

cavities (Hilliard 1979; Kantola 1 986) and in South 

Carolina, 20 percent of all nests are in cavities (Edwards 1986). However, Edwards (1 986) found that 

cavity use varies by sex and season. Use of 

cavities by males is low throughout the year (0 to 9 

percent) whereas cavity use by females varies from 

0 percent in summer to 69 percent in winter. Weigl 

and others (1 989) suggest that low cavity use by 

southeastern fox squirrels is due to low cavity 

availability. The relatively young pines in 

southeastern forests and the removal of large storm 

or fire damaged oaks during timber operations and 

for firewood presumably limit the number of available cavities. 

Although cavity use may be low, the availability of 

cavities may still be critical to the survival of fox 

squirrel populations. Nestbox and cavity use increases considerably during cold or rainy weather 

(Kantola 1986; Weigl and others 1989) as well as 

during periods of low food supply (Weigl and others 

1989). Further, Weigl and others (1 989) suggest 

that cavities are important for rearing of young. 

Thus, cavities may be important for successful 

reproduction as well as a means of conserving energy during periods of low energy supply or high energetic demands. 

A variety of tree species is used for leaf nest construction including loblolly pine, longleaf pine, slash 

pine, turkey oak, post oak, laurel oak, live oak, 

oak, blackgum, sweetgum, water tupelo, and 

cypress (Edwards 1986; Hilliard 1979; Kantola 

1986; Moore 1957). Whife Edwards (1 986) and Kantola (1 986) found that nests are placed predominantly in hardwoods (85 percent and 81 percent, 

respectively), Hilliard (1 979) found that pines (particulariy loblolly pine) are the predominant nest tree 

(81 percent). In Georgia, tree species are used in 

proportion to their availability for nesting (Hifliasd 

1979) whereas in South Carolina, fox squirrels show 

a preference for nesting in oaks (Edwards 1986). 

Fox squirrels also show a preference for larger trees 

(Edwards 1986; Kantola 1979). Mean dbh of nest 

trees in South Carolina is 41.2 cm (Edwards 1986) 

and mean dbh of nest trees in Georgia is 39.1 cm 

(Hilliard 1 979). 

Fox squirrels are considerably more terrestrial than 

other tree squirrels (MacClintock 1 970). In add it ion 

to spending much of their foraging time on the 

ground, they also run along the ground as a means 

of predator escape. The highly terrestrial nature of 

fox squirrels is probably due to their large size and 

consequent reduction in agility. The preference of 

fox squirrels for forests with sparse understories 

may be related to their terrestrial habits. An open 

understory allows for unhindered movement while 

on the ground as well as easier detection of 

predators (Taylor 1973). 

Home range size of fox squirrels in the Southeast 

(based on the minimum convex polygon method) 

ranges from 9 ha to 19 ha for females and from 20 

ha to 32 ha for males (table 1). These home range 

Table 1.--A summary of estimated home range sizes of southeastern fox 

squirrels (Sciurus niger). All estimates were determined by the minimum 

convex polygon method except for the estimates for S. Q. shermani which were 

determined by the 95 percent harmonic mean method, 

Home Range 

Location Size (ha) Source 

S. - n. einereus MD 29.9 Flyger and Smith 1980 

--Males NC 22,8 Weigl md others 1989 

S. 5 nig-er--Females NC 16.2 $3 

- 

--Males SC 31.~6 Edwards 1986 

- S, n. niger--Females SC 19.3 If 

- S. g. niger--Males G A 20,O Milliard 1979 ?Y --Females G A 9-0 

- S. n, shermani--Males FL 42.8 Kantola 9986; - S. 5. shermani--Females FL 16.7 qt 
sizes are considerably larger than those reported 

for fox squirrels in the midwest (Ha 1983). Ha 

(1 983) suggests that the large home range of fox 

squirrels in the Southeast is due to the lower, more 

patchy, and more unpredictable food supply found 

in southeastern forests. 

At this time, there is no evidence to suggest that fox 

squirrels are territorial. Home ranges often overlap 

(Hilliard 1979; Kantola 1986; Weigl and others 1989) 

and concurrent and non-concurrent use sf the 

same nest or nest box by 2 or more individuals has 

been obsewed (Hilliard 1979; Weigl and others 

1989). However, Weigl and others (1 989) suggest 

that close proximity among squirrels is rare and 

that they tend towards asocial behavior. Temporal 

spacing may thus be important in the spacing behavior of fox squirrels, and may also be an important factor in their large home range sizes. 

FUTURERESEARCHNEEDS 

From the studies reviewed above, a sketch emerges 

of the habitat relationships of fox squirrels in the 

Southeast. The squirrels occupy habitats with large 

pines, sparse ground cover, and an association of 

mature, mast producing oaks. The oaks may occur 

as a midstory component of pine stands or as small 

patches of hardwood communities intersecting or 

intermixed with pine communities. Edges between 

upland pines and bottomland hardwoods may also 

be important, particularly on a seasonal basis, for 

nesting and foraging habitat. Hardwoods provide 

the bulk of the annual diet while pines appear to 

provide a seasonally important food source. A 

sparse understory allows for efficient movement on 

the ground and possibly easier detection of potential predators. The large home range size of fox 

squirrels suggests that large tracts of suitable 

habitat are necessary to satisfy the needs of the fox 

squirrel. 

Our sketch of the habitat association of fox squirrels 

provides a generalized panorama of fox squirrel requirements, but it lacks the detail necessary to 

develop and prescribe management practices. Our 

current knowledge actually provides more questions than answers about fox squirrel ecology and 

management. What mixtures of pines and 

hardwoods provide optimum habitat for fox squirrels? Does it matter whether hardwoods occur as a 

mixture within pine stands or as hardwood stands 

adjacent to pine stands? Is stand or tree age an important factor versus some other attribute such as 

tree size or mast producing potential? What 

species of hardwoods and pines, are most important to fox squirrels? At what point can hardwood 

stocking become too high and begin to favor potential competitors such as the gray squirrel? Answers 

to these questions are essential for prescribing silvicultural practices and forest management 

strategies to favor fox squirrels. 

The ultimate goal of management oriented research 

on fox squirrels should be to discover the factors 

which influence or limit the distribution and abundance of the species. This may seem an obvious 

goal common to the popuiation ecology of any 

species (Elton 1 927; Andrewart ha and Birch 1 982, 

1984). Nonetheless, we feel it is important to explicitly restate the goal for this species to emphasize 

the research approach it implies. Understanding 

the fox squirrels' distribution and abundance requires understanding the species' innate capacity 

to increase in different environments. Too frequently we attempt to understand a species' ecology by 

studying either its environment or selected population parameters. However, population parameters 

are, in part, a function of, and vary among, different 

environments and the goal of management is to influence population dynamics primarily through 

modifications to the environment. Consequently, a 

comprehensive research approach must encompass both environmental parameters and population parameters and attempt to relate the two 

(And rewartha and Birch 1982). 

Determining the important environmental 

parameters to measure depends on a thorough 

knowledge and understanding of the food requirements and preferences, nest and nest site preferences, behavior patterns, and interactions with other 

species, particularly predators and competitors. 

Primary population parameters are birth and death 

rates, agents of mortality, and the age and sex structure of the population. Ultimately, habitat quality 

can be assessed by examining the population 

responses and behavior of fox squirrels in relation 

to environmental parameters (e.g., the availability of 

resources, the distribution of resources in space 

and time, and the abundance and distribution of 

competitors and predators). Thus, future research 

on fox squirrels should concentrate on determining 

their resource requirements and population 

dynamics under a wide variety of environmental 

conditions. 

The above outline of research focuses on defining 

optimal habitat for fox squirrels. Additional research topics also need to be addressed. For example, accurate methods to estimate population 

abundance and density are needed to monitor 

population trends as well as to test population 

responses to habitat variables. Thus, census techniques for this large, relatively sparse, and widely 

ranging species need to be developed and tested. 
Once these techniques are developed, monitoring 

of fox squirrel populations must be done to determine their status and population trends. Regional 

distributions should also be examined. The 

majority of fox squirrel studies in the Southeast 

have been conducted along the Atlantic Coast. It is 

necessary to determine the distribution and status 

of fox squirrels in the rest of the Southeast as well 

as to compare their ecologies with the fox squirrel 

populations in the Atlantic Coastal Plain and 

Sandhills Regions. Studies are now being conducted on S. n. - in the Piedmont Region of 

Georgia by researchers from Clemson University 

and on S. n. in Alabama by researchers 

from the U. S. Fish and Wildlife Service and data 

from these studies will complement previous studies 

as well as data that are now being collected in the 

Sandhills of North Carolina by researchers from 

Wake Forest University and in Florida. However, 

more of these types of studies are needed. Studies 

on the taxonomy and evolutionary relationships of 

the five southeastern subspecies relative to the rest 

of the subspecies would also be highly informative 

in understanding the adaptations of fox squirrels to 

the environmental conditions of the Southeast. 

Because there are many forest types both within 

and among physiographic regions in the Southeast, 

it is essential that habitats be defined clearly and 

precisely so that csmparisonr between areas and 

studies can be made. For example, the term pinehardwood is defined for National Forests as a stand 

containing 50 percent to 70 percent pine as 

dominants or codominants, However, in several 

studies (Edwards 1986; Hilliard 1979; Weigl and 

others 1989) this term is used to describe habitats 

that have predominantly pine in the overstory but 

oaks and other hardwoods as the main component 

of the midstory. "Eidge" and "ecotone" are also 

used in several studies but the precise definition of 

the habitat types they are describing are not given 

or are poorly defined. Differences in the use of 

terms to describe habitats or the poor definition of 

habitat terms is likely to lead to confusion and 

misunderstanding and thus ultimately, hinder our 

progress in fully understanding the habitat reiatisnships of southeastern fox squirrels. 

It is evident that a great deal of information is still 

needed before we fully understand the habitat 

relationships of fox squirrels in the Southeast and 

the importance of pine-hardwood mixtures to this 

species. However, the answers to the many questions about southeastern fox squirrels will not come 

from a few isolated studies. In order to determine 

the factors that limit the abundance and distribution 

of fox squirrels in the Southeast, studies covering a 

wide range of environmental conditions will be 

necessary. Further, due to both year-to-year variation in environmental parameters and the relatively 

long life span of this species, long-term studies are 

essential to the understanding of population responses to environmental variation and eventually, to environmental manipulation. 
LITERATURE CITED 

Andrewartha, H. C.; Birch, L. C. 1982. Selections 

from the distribution and abundance of animals. 

Chicago: University of Chicago Press. 275 pp. 

Andrewartha, H. C.; Birch, L. C. 1984. The ecological web. More on the distribution and abundance 

of animals. Chicago: University of Chicago Press. 

506 pp. 

Dueser, Raymond D.; Dooley, James L.; Taylor, 

Gary J. 1988. Habitat structure, forest composition and landscape dimensions as components of 

habitat suitability for the Delmarva fox squirrel 

(Sciuru~niaer cinereus). In: Szaro, R., ed. 

Management of amphibians, reptiles and small 

mammals in North America. in press. 

Edwards, John W. 1986. Habitat utilization by 

southern fox squirrel in Coastal South Carolina. 

Clemson, SC: Clemson University. 52 pp. Thesis. 

Elton, Charles. 1927. Animal ecology. London: 

Sidgwick and Jackson, Ltd. 209 pp. 

Flyger, Vagn; Gates, J. Edward. 1982. Fox and gray 

squirrels. pp. 209-229. In: Chapman, Joseph A.; 

Feldhamer, George A., eds. Wild mammals of 

North America: Biology, management, 

economics. Baltimore: The Johns Hopkins University Press. 

Flyger, Vagn; Smith, Deborah A. 1980. A comparison of Delmarva fox squirrel and gray squirrel 

habitats and home range. Transactions of the 

Northeast Section Wildlife Society 37: 19-22. 

Gurnell, John. 1983. Squirrel numbers and the 

abundance of tree seeds. Mammal Review 13: 133- 

148. 

Ha, James C. 1983. Food supply and home range 

in the fox squirrel (Sciurus niaer). WinstonSalem, NC: Wake Forest University. 32 pp. Thesis. 

Hail, E. Raymond. 1981. The mammals of North 

America. 2nd ed. vol. 1. New York: John Wiley 

and Sons. 600 pp. 

Hamilton, William J., Jr. 1943. The mammals of the 

eastern United States. Ithaca, NY: Cornstock 

Publishing Company, Inc. 432 pp. 

Hilliard, Thomas Harold. 1979. Radio-telemetry of 

fox squirrels in the Georgia Coastal Plain. Athens: 

University of Georgia. 102 pp. Thesis. 

Kantola, Angela T. 1986. Fox squirrel home range 

and mast crops in Florida. Gainesville: University 

of Florida. 67 pp. Thesis. 

MacClintock, Dorcas. 1970. Squirrels of North 

America. New York: Van Nostrand Reinhold Company. 184 pp. 

Moore, Joseph C. 1957. The natural history of the 

fox squirrel, Sciur~ niaer sherm. Bulletin of 

the American Museum of Natural History 1 13:7-71. 

Seton, Ernest Thompson. 1 953. Lives of game 

animals. vol. 4--Part 1. Boston: Charles T. Branford, Company. 440 pp. 

Taylor, Gary J. 1973. Present status and habitat survey of the Delmarva fox squirrel (Sciurus nige.~ 

cinereus) with a discussion of reasons for its 

decline. Proceedings Southeastern Association 

of Game and Fish Commissions 27:278-289. 

U.S. Department of the Interior, Bureau of Sport 

Fisheries and Wildlife. 1 970. Endangered Species 

of the United States. Washington, DC. 4 pp. 

Weigl, Peter D.; Steele, Michael A.; Sherman, Lori J 

[and others]. The ecology of the fox squirrel 

(-nlaer) in North Carolina: implications for 

survival in the Southeast. Bulletin Tall Timbers 

Research Station, in press. 

Wood, Gene W. 1988. The southern fox squirrel. 

Brookgreen Journal 18(3): 1-8. 
AVIFAUNA OF THE PINE-HARDWOOD FOREST IN EAST 

CENTRAL MISSISSIPPI 

Carroll J. Perkins and George A. ~urst' 

Abstract, -Birds in the interior of 3 mature (58 years old) pine-hardwood forests (PHF) 

and on edges of dirt roads (RDE) that traversed the PHF were studied in the Interior 

Flatwoods (Kemper County), Mississippi. Point counts (PT) and tape recorder counts 

(TR) were conducted from sunrise to 30 minutes later, from March-July 1972 and 1973. 

Number of males exhibiting territorial behavior was studied on 1 25 acre plot in a PHF 

in Spring 1973, Observations of birds in PHF and RDE were made during fall:winter 

1972 and 1973. A total of 24 species, 23 by PT and 18 by TR was observed in PHF, 

Species with the highest frequency indices were cardinal, tufted titmouse, Carolina 

wren, summer tanager, blue jay, American crow, Carolina chickadee, yellow-billed cuckoo, chipping sparrow, white-eyed vireo, and wood thrush. Combined PT and TR observations found 48 species on RDE. Of this total, 26 species were not observed in the 

PHF. Seventeen species exhibited territorial behavior in the PHF. During faillwinter 35 

species were observed in the PHF and 41 species were observed on RDE. 

INTRODUCTION 

Demand for wood products is increasing and the 

South is expected to produce more of the Nation's 

wood. One way to increase productivity, particularly pine (Pinu spp.), is to convert pine-hardwood 

forests to intensively managed pine plantations. 

Birds are a major component of southern forests 

and interest in songbirds is increasing. Habitat conditions are altered by converting pine-hardwood 

forests to pine plantations (Dickson and Segelquist 

1979, Darden 1980, Dickson and others 1980). The 

objective of this study was to document the 

avifauna of the pine-hardwood forest in east central 

Mississippi. 

DESCRIPTION OF THE STUDY AREA 

The study was conducted in the Interior Flatwoods 

land resource area (Kemper County) of the 

Southern Coastal Plain. The topography is flat and 

the area is poorly drained. Soils are clayey and 

acid. Mild winters and warm summers characterize 

the climate. Mean annual temperature is 60 degrees 

and average annual rainfall is 50 inches. The growing season averages 21 5 days (Pettry 1977). 

As late as 191 2 the flatwoods was a mixture of lobiolIY ( and shortleaf (P. pine, which was harvested from 191 2-1 941. Flinkote Company bought a large tract in 1941 and practiced 

selective cutting until 1 967. Weyerhaeuser Company bought the tract in 1967 and converted 

100,000 acres of pine-hardwood forest to loblolly 

pine plantations. 

'Retired Wildlife Biologist, Bainbridge, GA; Professor, 

Department of Wildlife and Fisheries, Mississippi State 

University, Mississippi State, MS. 

Three study areas, each consisting of 640 acres, 

were located in the northern, central, and southern 

part of Kemper County, respectively. An 80-acre 

plot in each area was used for the bird study. The 

forests were homogeneous (Perkins 1973). 

A pine-hardwood forest (PHF) occupied all study 

areas. The overstory contained 14 species and was 

dominated by pines. Post oak (Quercus 

was the dominant hardwood, followed b rn 

red oak (Q. fm, white oak (Q. w, hickories (w spp.), sweetgum , 

red maple (Acer rubrum), 

m. Pine basal area averaged 46 square feet per 

acre and hardwood averaged 53 square feet per 

acre. Average pine diameter at breast height (dbh) 

was 15.3 inches and hardwood averaged 10.2 in- I 

ches. Dominant pine trees averaged 50 years old 

and averaged 73 feet tall. Hardwood trees averaged 

57 years old. 1 

i 

The understory stratum contained 27 species, 1 4 of 

which were in the overstory. Post oak was the 

dominant species, followed by sweetgum, pines, 

and red oak. Pine basal area averaged 17 square 

feet per acre and hardwood averaged 53 square 

feet per acre. Pine dbh averaged 5.7 inches and 

hardwood 5.9 inches. Average pine age was 26 

years and hardwood 44 years. 

The transgressive stratum, woody stems between 5 

feet high and 1 inch dbh, contained 32 species, 23 

of which occurred in the understory. Sweetgum was 

dominant, followed by blackgum ( 8 

hickories, red maple, and pines. 

The low woody stratum, stems below 5 feet tall, contained 36 species, 27 of which occurred in the transgressive stratum. Poison ivy ( ) t 
greenbrier ( 

spp.) and red maple dominated this stratum. 

The herbaceocis stratum contained 55 species, 43 

sf which were Forbs; 9 were grasses, and 3 were 

sedges Of these species, 48 were perennials and 7 

were annuals. Bioclea ( 

dominant species, Folio 

"i"i"2, Perkins 4 973). 

A company road traversed each study area. The 

forest on a 58-foot-wide strip was cleared, and a 26- 

foot-wide, d irtigravef road was made. Road 

shoulders, about 12 feet wide, were left untended 

and a secondary successional plant community 

developed. A11 roads were bordered by PHF. 

Point counts Werner 1985) were conducted at randomly established points in the 3 PHF. While 

remaining at the point, the observer recorded all 

bircds seen or heard, from March-July 1972 and 

"1973 Counts began at sunrise and continued for 30 

minutes. The 2 observers alternated between the 3 

areas and a total of 10 counts was made. Points 

were at least I00 yards within a PHF, avoiding 

edges or other habitat types. Only birds thought to 

be on the sample area (not just flying over) were 

recorded. Binoculars and a spotting scope 

facilrtated bird identification. A frequency index was 

calccaiated far each species (Kricher 1373). We did 

not estimate bird densities Werner and Lyman 

3 985) Scientific names of bird species are listed in 

the Appendix. 

Point counts were also conducted on edges of 

roads in the 3 PHF. Points along the roads were randomly selected and 12 counts were made during 

the same time and dates as PHF. Birds seen or 

heard on or near the roadlPHF edges were 

recorded. 

%ape recorder counts were conducted by systematically placing a rape recorder (Sony TC 8006 with 

Sony F-26s cardioid dynamic microphones or 

similar models) in the PHF, Tape recorder points 

were about 1i4 mile from obsewer points The tape 

recorder was placed on the ground but the 

microphoraes were situated about 7 feet above the 

ground. Nine tape counts were made during the 

same rime and dates as point counts. Tapes were 

pIa yed back and species vocalizations were identified and counted. A frequency index was calculared for each species. 

Tape recorder counts (I 6) were also conducted on 

road edges. The recorder was placed near the 

edge of the road and the methods were the same 

as for those in PHF. 

One breeding bird census ptot (t4all 1964) was established in 1 PHF. The plot (25 acres) was divided 

into 25 1 acre blocks and was censused 33 times in 

Spring 1973. Territory boundaries for each bird exhibiting territorial behavior were delineated and the 

size of the territory was measured. Number of territories for each species was counted. In addition, 

point counts (13) and tape recorder counts (9) were 

conducted on the plat in SpringiSummer 1973 

Project personnel recorded all birds seen or heard 

in the PHF and road edges while working on other 

objectives in Fall,Winter (OctoberiFebruary) 1 971 - 

72 and 1972-73. 

RESULTS 

A total of 23 species was observed on point counts 

(PTS) in PHF. Species with the highest frequency indices (FI) were cardinal, Carolina wren; tufted titmouse, blue jay, summer tanager, and pileated 

woodpecker (table 1 ). 

Tape recorder counts FRS) detected 18 species in 

PI-IF. Species with the highest FI were cardinal, 

tufted titmouse, summer tanager, yellow-billed cuckoo, wood thrush, and chipping sparrow Six 

species were observed at PIS that were not 

detected at TRS. The red-eyed vireo was detected 

at TRS but was not observed on PIS. Of the 24. 

species obsewed or recorded, 9 were summer residents and 15 were permanent residents. 

On road edges (RDE) 38 species were obsewed by 

PTS and 38 were detected by TRS. Ten species 

were observed by PTS that were not detected by 

TRS, and 10 species were detected by IWS that 

were not obsewed by PTS. Species with the highest 

Fl on PTS were cardinal, summer tanager, Carolina 

wren, mourning dove, wood thrush, and indigo 

bunting. Species with the highest FI at TRS were 

Carolina wren, tufted titmouse, cardinal, and barred 

owl. 

A total of 48 species was sbsenled or recorded by 

PTS and TRS on RDE. All species, except the redeyed vireo, observed or recorded in the PHF were 

atso seen or recorded on RBE. Twenty six additional species were obsented or recorded on RBE. Of 

these 26 species those with the highest FI were 

Kentucky warbler, chuck-will's-widow* barred owl, 

rufous-sided towhee, indigo bunting, and yellowbreasted chat. Twenty-one of the 26 species here 

summer residents. 
Table 1. Frequency indices from point and tape recorder counts from the interior and 

road edges, Spring/Summer 1972 and 1973, and a breeding bird census plot, Spring 1973, 

in pine-hardwood forests, Kemper County, Mississippi 

Interior Road edges Breed, plot 

Pt TR Pt TR Pt TR 

Species cts 

Cardinal 100.0 

Carolina wren 90.0 

Tufted titmouse 80.0 

Blue jay 70. 0 

Summer tanager 60.0 

Pileated woodpecker 60.0 

American crow 50.0 

Carolina chickadee 50.0 

White-eyed vireo 50.0 

Mourning dove 40.0 

Yellow-billed cuckoo 40.0 

Red-headed woodpecker 30.0 

Wild turkey 30.0 

Wood thrush 30.0 

Red-shouldered hawk 20.0 

Chipping sparrow 20.0 

Blue-gray gnatcatcher 20.0 

Red-bellied woodpecke 10.0 

Cooper's hawk 10.0 

Prothonotary warbler 10.0 

Northern bobwhite 10.0 

Great crested flycatcher 10.0 

Yellow-throated vireo 10.0 

Red-eyed vireo - - 

Kentucky warbler - - 

Gray catbird -- 

Chuck-will's-widow - - 

Ruby-throated hummingbird -- 

Pine warbler - - 

Barred owl - 

Ruby-crowned kinglet - - 

Eastern wood-peewee - - 

Black-and-white warbler -- 

Rufous-sided towhee - - 

Whip-poor-will -- 

Chimney swift - - 

Orchard oriole -- 

Brown thrasher -- 

Indigo bunting - - 

Yellow-breasted chat - - 

Blue grosbeak - - 

Green heron - - 

Brown-headed nuthatch -- 

American robin -- 

Northern flicker - - 

Common grackle -- 

Brown-headed cowbird -- 

White- throated sparrow -- 

Bewick's wren -- 

Eastern bluebird -- 

cts 

100.0 

33 3 

100 * 0 

33.3 

100.0 

33.3 

33.3 

55 * 6 

22.2 

11.1 

cts 

100.0 

75.0 

58.3 

58.3 

91.7 

41.7 

25.0 

25.0 

50.0 

66.7 

58.3 

33.3 

8.3 

66.7 

16.7 

50.0 

25.0 

- - 

cts 

81.3 

100.0 

93.8 

43.8 

50.0 

56.3 

37 5 

31.3 

31.3 

37+5 

25.0 

12.5 

25.0 

56.3 

12.5 

31 3 

6.3 

12.5 

- - 

6.3 

31.3 

- - 

50.0 

- - 

18.8 

- - 

37 - 5 

- - 

25.0 

62.5 

- mm 

12.5 

- - 

43.8 

6-3 

- - 

-- 

-- 

18.8 

6.3 

- - 

-- 

12.5 

6.3 

4.3 

25.0 

6-3 

6.3 

6.3 

6.3 

cts 
Table 2. Territory size and number of territories on a breeding 

bird census plot in a pine-hardwood forest, Spring 1973, Kemper 

County, Mississippi 

Species Territory size Number of territories 

(acres) per 25 acres 

Cardinal 3.50 3 . 5 

Summer tanager 2.75 3.5 

Tufted titmouse 3.75 3 . 5 

Carolina chickadee 2.75 3.0 

Blue-gray gnatcatcher 1.25 3.0 

Black-and-white warbler 0.50 2.5 

Chipping sparrow 2.25 2 e 5 

Carolina wren 2.25 2.0 

Blue jay > 5.00 2.0 

White-eyed vireo 1.50 2.0 

Red-eyed vireo 2.25 2.0 

Red-headed woodpecker > 3.00 2.0 

Yellow-throated vireo 1.50 1.5 

Wood thrush > 5.00 1.5 

Eastern wood-peewee 1.22 1.0 

Pileated woodpecker - - -- 

Mourning dove -- - - 

a Not determined 

Seventeen species exhibited territorial behavior on 

the plot (table 2). Most prominent were cardinal, 

summer tanager, and tufted titmouse, with 3.5 territories each. Territory size ( 5 acres) was largest for 

the blue jay and wood thrush. 

A total of 22 species was observed by PTS and 18 

by TRS on the breeding bird plot (table 1 ). The yellow-billed cuckoo had high FI on PTS and TRS but 

did not exhibit territorial behavior. 

In the falllwinter, 35 species were observed in the 

PHF. No species was considered to be abundant, 

14 species were common, and 21 species were 

rare. Only 9 species (dark-eyed junco, brown 

creeper, ru by-crowned kinglet, eastern phoebe, 

white-throated sparrow, hermit thrush, yellowrumped warbler, palm warbler, and yellow-bellied 

sapsucker) were thought to be winter residents, the 

other species were transients. 

Forty-one species were sbsewed on RDE in the 

faliiwinter. Ten species not seen in PHF were seen 

on RDE. Three species (chipping sparrow, field 

sparrow, and yellow-rumped warbler) were rated as 

abundant, 22 were common, and 16 were rare 

( Perkins 1 973). 

DISCUSSION 

Twenty-four species were observed in PWF and 

twice as many (48) were observed on RDE in springsummer. Twenty-six species were observed only on 

RDE. Lay (1938) reported that the edge of a 

forested area contained more birds and more bird 

species than areas within the forest. Similarly, 

Strelke and Dickson (1 980) found that the number 

of breeding bird species, species diversity, and 

abundance were higher at or in pine-hardwood 

forest edges than in the forest interior or adjacent 

clearcuts in Texas. O'Meara and others (1985) 

found that the highest bird densities, in all seasons, 

occurred in edge habitats in Bradford County, 

Florida. The edges and early successional plant 

communities on road shoulders will be maintained 

by control burning the pine plantations and by 

removal of all pine trees (to a depth of 25 feet) on 

road edges. 

In southern forests, 1 5 species were listed as preferring deciduous and coniferous (hardwood-pine) 

type forest for breeding (Shugarl and others 1978). 

The cardinal was not on this list. Of the 15 species, 

only 1, the Carolina chickadee, was found to be 

breeding in the PHF in Mississippi. Bickson and 

others (1 980) rated 15 species as Present, 12 as 

Regular, and 7 as Common in the pine-hardwood 

forest type. Our data agree with their ratings for 

Common species, except the Kentucky warbler was 

not common in our study areas in PWF. 
A total of 17 species exhibited territorial behavior in 

the PHF. More species, such as hawks, owls, and 

wild turkey, undoubtedly nest in the PHF (Perkins 

1973). Only 1 census plot was used. Myers and 

Johnson (1 978) reported 20 breeding species in 

mesic PHF. Five species (blue-gray gnatcatcher, 

chipping sparrow, white-eyed vireo, red-headed 

woodpecker, and mourning dove) showed breeding 

behavior in PHF of Mississippi but were not listed 

by Meyers and Johnson (1 978). 

Dickson and Segelquist (1 979) noted territorial behavior by 18 species in pine-hardwood forests (sawtimber, 65 years old) in east Texas. Their most 

numerous species were cardinal, red-eyed vireo, 

Carolina wren, and tufted titmouse. Eleven species 

were found both in Texas and Mississippi, but 6 

were found breeding in Mississippi and 5 (4 

warblers) in Texas that were not found in the other 

state, 

Childers and others (1 986) found 18 species of 

breeding pairs in second growth PHF in the central 

Piedmont of Virginia. The more abundant breeders 

were red-eyed vireo, ovenbird, scarlet tanager, and 

blue jay. Ten species were common to Mississippi 

and Virginia, with 8 in Virginia and 7 in Mississippi 

not recorded for the other state. The cardinal was 

not listed as a breeding species in eentrai Virginia. 

Noble and others (1 980) reported that the highest 

breeding bird population (1 888id 80 acres) occurred 

in a PHF in Livingston Parish, Louisiana. This forest 

was uneven-aged, had many over-mature trees, 

and had not been disturbed for at least 50 years. 

They observed 32 species of breeding birds in this 

forest. 

Only 9 of the 35 species observed in PHF were 

winter residents. Dickson and Segelquist (1 978) 

reported 15 species in the PHF in east Texas from 

January-March (winter). Forty-one species were observed on RDE next to PHF. Most of these were 

also transients. 

In the PHF, more species were observed by point 

counts than by tape recorder counts, and the FI 

changed for some species according to sample 

type, Tape recorders were thought to be more sensitive than human ears, were not distracted, were 

economical, and yielded an irrefutable record of 

bird vocalizations. However, tape recorders had 

mechanical problems, lacked subjectivity about 

bird location, and some persistent, vociferous birds 

received too much emphasis. A bird very close to 

the microphones could obliterate less vociferous 

birds. Tape recorders only detect singing birds, so 

they can not replace human sightihearing. 

No species was found to be unique to PHF (Perkins 

1993). Several of the species were considered ubiquitous species (Djckson and others 1980). The only 

endangered species, red-cockaded woodpecker, 

was rarely seen in the PHF, 

AGKNOWLEDGEMEPSTS 

The project was funded by Weyerhaeuser Company 

and the Mclntire-Stennis Forest Research Program. 

We thank 6. Perkins, S. Weir, 8. McKee, and R. 

Romedy for their assistance. 

LITERATURE CITED 

Childers, Eddie L.; Sharik, Terry L.; Adkisson, Curiis 

S. 1986. Effects of loblolly pine plantations on 

songbird dynamics in the Virginia Piedmont* 

Journal of Wildlife Management 50(3): 406-41 3. 

Darden, Tom L., Jr. 1980. Bird communities in 

managed loblolly-shortleaf pine stands in east 

central Mississippi. M. S. Thesis, Mississippi 

State University, Mississippi State, MS. 1 17 pp. 

Dickson, James G.; Segelquist, Charles A. 1978. 

Winter bird populations in pine and pinehardwood forest stands in east Texas. 

Proceedings Annual Conference of Southeastern 

Fish and Wildlife Agencies 31 : 134-1 37. 

Dickson, James G.; Segslquist, Charles A. 1979. 

Breeding bird populations in pine and pinehardwood forests in Texas. Journal of Wildlife 

Management 43(2):543-555. 

Dickson, James G.; Gonner, R.N.; Williamson, J.H. 

1980. Relative abundance of breeding birds in 

forest stands in the Southeast. Southern Journal 

of Applied Forestry 4: 174-1 79. 

Hall, G. 1964. Breeding bird censuses, why and 

how. Audubon Field Notes 18:81-109. 

Kricher, J. 1973. Summer bird speeies diversity in 

relation to secondary succession on the New Jersey Piedmont. American Midland Naturalist 

89: 121 -1 35. 

Lay, D. W. 1938. How valuable are woodland clearings to birdlife? Wilson Bulletin 50:254-256. 

McKee, W. C. 1972. Habitat productivity of the interior flatwoods in Kemper County, Mississippi. 

M.S. Thesis, Mississippi State University, Mississippi, MS 64 pp. 

Meyers, J. M.; Johnson, A,$. 1978. Bird communities associated with succession and 

management of loblolly-shortleaf pine forests. 

Pages 50-65 & R. M. DeGraff, tech. coord. proc. 

of the workshop management sf southern forests 

for nongame birds. U.S. For. Sew. Gen. Tech. 

Rep. SE-14. 
Noble, R. E.; Hamilton, R.B.; McComb, W.C. 1980. 

Some effects of forestry on nongame birds. 

Pages 65-78 &J Integrating timber and wildlife 

management in southern forests, R. H. Chabreck 

and R. ti. Mills, eds. Proe. 29th Annu. Forestry 

Symp. Louisiana State University, Baton Rouge, 

LA. 119 pp. 

O'Meara, Timothy E.; Rowse, Lesley A.; Marion, 

Wayne R.; Harris, Larry D. 1985. Numerical 

responses of flatwoods avifauna to clearcutting. 

Florida Scientist 48:208-219. 

Strelke, William K. ; Dickson, James G. 1980. Effect 

of forest clear-cut edge on breeding birds in east 

Texas. Journal of Wildlife Management 44(3):559- 

567. 

Verner, Jared. 1985. Assessment of counting techniques. Pages 247-302 jn R. F. Johnston, ed. 

Current Ornithology, Vol. 2. Plenum Publ. Corp., 

New York. 

Verner, Jared; Ritter, Lymon V. 1985. A cornparison of transects and point counts in oak-pine 

woodlands of California. The Condor 87:47-68. 

Shugart, H. H.; Smith, T.M.; Kitchings, J.T.; 

Kroodsma, R.L. 1978. The relationship of nongame birds to southern forest types and 

successional stages. Pages 5-1 6 in R. M. DeGraff, tech. coord. proc. of the workshop 

management of southern forests for nongame 

birds. U.S. For. Serv. Gen. Tech. Rep. SE-14. 
Appendix Table 1. Scientific nmes of birds in the text, 

Species scientific name 11 Species Scientific name 

Cardinal 

Carolina wren Winter wren Tufted titmouse 

Carolina chickadee 

Blue jay 

Summer tanager 

Scarlet tanager 

Pileated woodpecker 

Anterican crow Whi te-eyed vireo 

Yellow-throated vireo 

Red-eyed vireo 

Mourning dove 

Yellow-billed cuckoo 

Red-headed woodpecker 

Red-bellied woodpecker 

Wild turkey 

Wood thrush 

Red-shouldered hawk 

Chipping sparrow 

Field sparrow 

Blue-gray gnatcatcher 

Cooper ' s hawk 

Prothonotary warbler 

Northern bobwhite 

Great crested flycatcher 

Kentucky warbler 

Gray catbird 

Chuck-will's-widow 

Ruby-throated hummingbird 

Pine warbler 

Barred owl 

Ruby-crowned kinglet 

Golden-crowned kinglet 

Eastern wood-peewee 

Black-and-white warbler 

Rufous-sided towhee 

Whip-poor-will 

Chimney swift 

Orchard oriole 

Brown thrasher 

Indigo bunting 

Yellow-breasted chat 

Blue grosbeak 

Green heron 

Brown-headed nuthatch 

White-breasted nuthatch 

Cardinalis cardinalis 

Trogldytes ludovicianus 

z. troglodytes -- Parus bicolor 

P. carolinensis 

Cyanocita cristata 

Piranga rubra 

-- P. olivacea 

Dryocopus pileatus 

Corms brachyrhynchos 

Vireo griseus 

V. flavifrons 

-- V. olivaceus 

-- Zenaida macroura Coccyzus americanus 

Melanerpes erythrocephalus M. carolinus 

Meleagris gallopavo 

Hylocichla mustelina 

Buteo lineatus 

Spizella passerina 

S. pusilla caerulea 

Accipiter cooperii 

Protonotaria citrea 

Colinus vir~inianus 

Myiarchus crinitus 

Oporornis formosus 

Dwnetella carolinensis 

Caprimulgus carolinensis 

Archilochus colubris 

Dendroica pinus 

Strix varia 

Regulus calendula I I 

R. satrapa 1 I 

Contopus virens 

Mniotilta varia 

Pipilo erythrophthalmus 

Caprimulms vociferus 

Chaetura pela~ica 

Icterus spurius 

Toxostoma rufwn 

Passerina cyanea 

-- Icteria virens 

Guiraca caerulea 

Butorides virescens 

Sitta pusilla 

S . carolinensis 

Aarerican robin 

Nortbrn flicker 

Comun grackle 

Brown-headed cowbird 

White- throated sparmw 

Bewick's wren Eastern bluebird 

Yellow-mped warbler 

Acadian flycatcher 

Ovenbird 

Hermit thrush 

Red-cockaded woodpecker 

Eastern phoebe 

Turdus migratorius 

Colaptes auratus 

Quiscalus quiscula 

Molothrus 

Zonotrichia albicollis 

Tfiryoaanes bewickii 

-- Sialia sialis 

Dendroica comnata 

Empidonax virescens 

Seiurus aurocapillus 

Catharus guttatus 

-- Picoides borealis 

Sayornis phoebe- 
AVIAN COMMUNITIES OF PINE-HARDWOOD 

FORESTS IN THE SOUTHEAST: 

CHARACTERISTICS, MANAGEMENT, AND MODELING 

Theodore A. Kerpez and Dean F. ~tauffer' 

Abstra. -We used information on wildlife habitat relationships to predict the effects of forest 

management actions on avian species in southeastern pine-hardwood forests, and compared 

our predictions to published field studies. Pine-hardwood forests provide optimal or suitable 

habitat for more wintering bird species than loblolly-shortleaf pine or oak-hickory forests and for 

more breeding bird species than loblolly-shortleaf pine forests. If all the pine-hardwood stands 

in a forest were converted to loblolly-shortleaf pine or oak-hickory stands, up to 9 bird species 

probably would be extirpated from the forest. Generally, at least twice as many species were 

predicted to be negatively affected by clearcutting than positively affected for all combinations 

of stand age, time of effect, and season that were examined. A large number of bird species 

was predicted to be negatively affected immediately after burning, but this effect would only last 

about a year, and then many of these species were predicted to be positively affected for 5 to 

10 years. There were many more species for which we could not predict the effects of thinning 

than for which a prediction could be made. A substantial number of bird species were predicted 

to be negatively affected by the removal of snags during clearcutting or thinning. 

INTRODUCTION 

Forest management that alters the composition or 

structure of forest vegetation will affect wildlife 

habitat and populations. In the past, forest 

managers usually considered the effect of forest 

management only on game species. However, 

many forest managers must now consider the effects of forest management on all wildlife. The National Environmental Policy Act of 1969 requires 

that the environmental impacts of any federally 

funded land management program be examined 

and evaluated. The Endangered Species Act of 

1973 mandates that endangered and threatened 

species on Federal lands be protected and 

managed, and prohi bits adverse impacts on critical 

habitat for endangered and threatened species. 

Also, the National Forest Management Act of 1976 

directs National Forest managers to manage for 

biological diversity and maintain viable populations 

of all native and desirable exotic vertebrates. These 

and other laws and regulations have greatly increased the demand for information on the effects 

of forest management on all wildlife species. 

The most reliable sources of information for evaluat - ing the effects of forest management on wildlife are 

experimental field studies. However, very few of 

these studies have been done in pine-hardwood 

forests. Also, these studies often provide good information only for species that are most abundant and 

'~raduate Research Assistant and Associate 

Professor, respect~vely, Department of Fisheries 

and Wildlife Sc~ences. Virg~nia Polytechnic lnst~tute 

and State Univers~ty Blacksburg. VA. 

easiest to census. These may not be the most important species, and are certainly not the only 

species that need consideration. 

Another approach to assess forest management is 

to use information on wildlife habitat relationships 

to predict the effects of forest management on 

wildlife. If we understand the habitat ecology of a 

species and we know how a forest management action affects the habitat, we should be able to predict 

the effect on the species. These predictions can 

provide managers with information for current planning and can be used by researchers as working 

hypotheses. 

Our objective was to use wildlife habitat relationships to predict the effects of forest management actions on avian species in southeastern 

pine- hardwood forests. We examined the effects of 

clearcutting, controlled burning, and thinning on 

bird species that commonly use southeastern pinehardwood forests. We then compared our predictions to the results of the few published field studies 

on the effects of forest management on birds in 

southeastern pine-hardwood forests. Pinehardwood stands in the southeast often are converted to loblolly pine (Pinus taedilj and/or shortleaf 

pine (P. shinat@ stands, or, because of lack of site 

preparation, regenerate to oak-hickory stands. 

Therefore, we compared the suitability of loblollyshortleaf pine, oak-hickory, and pine-hardwood 

stands for birds. 
METHODS 

We developed our models from an extensive review 

of avian habitat relationships on southeastern forest 

lands compiled by Hamel and others (1 982). This 

review is a synthesis of the literature and expert 

opinions. Some of the information has not been empirically verified; however, it is the best comprehensive source of information about avian habitat 

relationships on southeastern forest lands presently 

available. 

For each bird species that Hamel and others (1982) 

listed as commonly using pine-hardwood forests in 

the Southeast, we entered the following information 

into a computer data base: a habitat suitability 

rating of optimal, suitable, marginal, or unsuitable 

for each of 4 successional stages (grass-forb, shrubseedling, sapling-pole timber, and sawtimber); 

whether the species uses bare soil, thick deciduous 

leaf litter, herbaceous ground cover, shrubs, 

midstory canopy, overstory canopy, or dead trees 

or limbs; and whether the species requires closed 

canopy, open canopy, snags, or slash. Hamel and 

others (1 982) defined optimal habitat as habitat in 

which the species occurs in highest frequency, 

greatest numbers, or both. Suitable and marginal 

habitats were defined as habitats in which the 

species occurs in successively lower numbers and 

frequency. A habitat was considered unsuitable if 

the species was unlikely to occur in that habitat. All 

species information was separated into breeding 

and wintering habitat. 

We examined the effects of clearcutting both pinehardwood sawtimber and pole timber. The effects 

of clearcutting sawtimber were predicted for 3 time 

periods; immediate effects, short-term effects, and 

long term effects. To predict the immediate effects 

of clearcutting sawtimber we compared the habitat 

suitability rating of sawtimber to the habitat 

suitability rating of the grass-forb successional 

stage for each species. If the habitat suitability 

rating was greater for the grass-forb successional 

stage than for sawtimber, a positive effect was 

predicted (optimal suitable marginal unsuitable). 

If the habitat suitability rating was less for the grassforb successional stage than for sawtimber, a negative effect was predicted. If the habitat suitability 

rating was equal in the grass-forb successional 

stage and in sawtimber, no effect was predicted. 

We used the same process to predict the short-term 

effects of clearcutting sawtimber except that the 

habitat suitability rating of the shrub-seedling successional stage was compared to the habitat 

suitability rating of sawtimber. To predict the longterm effects of clearcutting sawtimber, we compared the habitat suitability rating of the 

sapling-pole timber successional stage to the 

habitat suitability rating of sawtimber. We predicted 

the immediate and short-term effects of clearcutting 

pole timber as defined above, except that pole timber was compared to the grass-forb and shrubseedling successional stages. 

The time period for each of the successional stages 

varies with site conditions. Therefore, the time 

periods associated with the immediate, short-term, 

and long-term effects of clearcutting are best determined by local managers. 

We also examined the effect of snag removal during 

clearcutting. A species was predicted to be negatively affected by snag removal if the species required or used snags and the species had an 

optimal or suitable habitat rating in the grass-forb 

or shrub-seedling successional stages. Snag 

removal probably has little effect on species for 

which the habitat is marginal or unsuitable, and 

most snags left during clearcutting probably do not 

last past the shru b-seedling successional stage 

(Dickson and others 1983). 

The effects of controlled burning and thinning were 

predicted based on habitat components that each 

species required or used. From a literature review 

we determined the effects of burning and thinning 

on habitat components. If a treatment increased 1 

or more habitat components required or used by a 

species, the effect was predicted to be positive for 

that species. The effect was predicted to be negative for a species if a treatment decreased 1 or more 

habitat components required or used by that 

species. If a treatment increased and decreased 

habitat components required or used by a species, 

we could not predict the effect. We predicted the 

treatment would have no effect on species that did 

not require or use any of the habitat components affected by a treatment. 

We determined that the immediate effects of burning are decreases in deciduous leaf litter, herbaceous ground cover, shrubs, slash, and snags 

and an increase in the amount of bare soil (Dickson 

1981 ; Lander 1987; Lewis and others 1982; 

O'Halloran and others 1987; Van Lear and Johnson 

1983; Wood and Niles 1978). Leaf litter, herbaceous ground cover, shrubs, snags, and slash 

are consumed by the fire, leaving more bare soil. 

These immediate effects usually last about a year, 

but the time period varies with site conditions. The 

short-term effects that follow are increases in herbaceous ground cover and shrubs, and a continued absence of slash (Cushwa and others 1969; 

Dickson 1981 ; Lander 1987: Lewis and others 1982; 

O'Halloran and others 1987; Resler 1972; Van Lear 

and Johnson 1983; Wood and Niles 1978). Fire 

stimulates the growth of herbaceous ground cover 

and shrubs, and after about a year they increase 

beyond the amount present before burning (Cushwa and others 1969; Dickson 1981 ; Lewis and 
others 1982; Resler 1972; Van Lear and Johnson 

1983; Wood and Niles 1978). Deciduous leaf I itrer 

returns to about the previous depth in 1 to 2 years 

(O'Halloran and others 1987). The increase in herbaceous ground cover and leaf litter restores the 

amount of bare soil to about the amount present 

before burning, Snags consumed by fire often are 

replaced within a few years by trees killed by fire 

(Lander 1987; Van Lear and Johnson 1983). 

However, slash consumed by fire usually is not 

replaced. The short-term effects of burning may 

last from 5 to 10 years; the time period depends on 

the site conditions. 

We determined that thinning decreases overstory 

canopy and midstory canopy and increases herbaceous ground cover, shrubs, and slash (Dickson 

1981 ; Hooper 1978; McComb 1982; Zeedyk and 

Evans 1975). The removal of trees decreases the 

overstory and midstory canopies which allows more 

light to reach the forest floor, which stimulates herbaceous ground cover and shrub growth (Dickson 

1981 ; Hooper 1978; McComb 1982; Zeedyk and 

Evans 1975). Slash piles are usually created when 

trees are cut. The effects of thinning may last from 

5 to 10 years; the time period depends on the site 

conditions. We also examined the eNect of snag 

removal during thinning. A species was predicted 

to be negatively affected by snag removal if the 

species required or used snags. 

We examined the effects of controlled burning on 

avian species in sawtimber, pole timber, and clearcuts (grass-forb successional stage) and the effects 

of thinning on avian species in saMimber and pole 

timber, because these are likely management actions. Effects were predicted only for species with 

an optimal or suitable habitat rating in the suecessional stage under consideration. Habitat changes 

caused by burning or thinning probably have little 

effect on species for which the successional stage is 

marginal or unsuitable habitat. 

We also used information from Wamel and others 

(1 982) to compare the suitability of Ioblolly-shortleaf 

pine, oak-hickory, and pine hardwood stands for 

birds. We determined the number of breeding and 

wintering bird species that had an optimal or 

suitable habitat rating in each of the successional 

stages of pine-hardwood, loblolly-shortleaf pine, 

and oak-hickory forests. We also determined the 

number of breeding and wintering bird species that 

had an optimal or suitable habitat rating in I or 

more of the successional stages of pine-hardwood 

forests but did not have an optimal or suitable 

habitat rating in any successionaf stage of loblollyshortleaf pine forests or aak-hickory forests. 

Throughout the modeling, all bird species that were 

listed by Hamel and others (1982) as commonly 

using pine-hardwood Forests in the Southeast were 

included. All the species may not be present in a 

particular forest. This should be considered when 

interpreting summaries such as the number of 

species positive! y affected by clearcutting savritimber Local rnanagers need to determine which 

species are present in their forests. Hamel and 

others (1982) provide range maps and other information that is useful. Field guides, state data 

bases, and local birding clubs also may be helpful. 

RESULTS AND DISCUSSION 

Forests 

The number of bird species with an optimal or 

suitable habitat rating generally increased with the 

age of the successional stage in all 3 forest types 

(table 1 ). SaWimber can provide eptimal or 

suitable habitat for more than twice as many 

species as any other successional stage in all 3 

forest types, except for wintering birds in the sapling-pole timber stage (table 1). A general increase 

in the number of breeding bird species present as 

ecological age increased, with mature forests 

having the greatest number of breeding bird 

species, was found in upland seres in Georgia 

(Johnston and Qdum 1956) and Arkansas (Shugart 

and James 1973), and in oak-chestnut seres in 

North Carolina (Odum 1950). These results indicate the importance of mature forests to many bird 

species and to the maintenance of biological diversity. 

Table I.-- The number sf breeding and wintering bird species with 

an optimal or suitable habitat rating in each successicnal stage 

and for all stages combined of pine-hardwood, loblolly-shortleaf 

pine, and oak-hickory forests in the Southeast (data compiled 

from Hamel and others 198Z). 

Grass- Shrub- Sapling- Saw- All 

Season/ fores t type f~rb seedling pole timber stages 

Breeding 

Pine-hardwood 12 14 16 43 62 

Loblolly-shortleaf 10 11 13 29 46 

Oak-hickory 13 13 15 49 73 

Wintering 

Pine-hardwood 21 14 34 46 65 

Lobiolly-shortleaf 2G 13 28 41 56 

Oak-hickory 19 12 15 27 48 

Pine-hardwood forests can provide optimal or 

suitable habitat for more wintering bird species than 

loblolly-shofifeaf pine or oak-hickory forests and for 

more breeding bird species than Ioblolly-shortleaf 

pine forests (table 1 1. Pine-hardwood forests 

provide optimal or suitable habitat for 21 breeding 

species and 16 wintering species for which loblollyshoflleaf pine forests do not. Pine-hardwood 

forests also provide optimal or suitable habitat for 

10 breeding species and 23 wintering species for 

which oak-hickory forests do not. Pine-hardwood 
forests provide optimal or suitable habitat for 3 

breeding species (long-eared owl [see appendix for 

scientific names], black-throated green warbler, 

and Bachman's sparrow) for which neither loblollyshortleaf pine or oak-hickory forests provide optimal or suitable breeding habitat. Pine-hardwood 

forests also provide optimal or suitable habitat for 6 

wintering species (turkey vulture, black vulture, 

ruffed grouse, chuck-will's-widow, black-and-white 

warbler, and ovenbird) for which neither lobiollyshortleaf pine or oak-hickory forests provide optimal or suitable wintering habitat. 

These comparisons indicate the importance of pinehardwood forests to avian species. Conversion of a 

pine-hardwood stand to a loblolly-shortleaf stand 

would likely decrease the number of bird species 

for which that stand can provide good habitat and 

can negatively affect a large number of bird 

species. Conversion of a pine-hardwood stand to 

an oak-hickory stand can also negatively affect a 

large number of bird species. If all the pinehardwood stands in a forest were converted to 

loblolly-shortleaf pine or oak-hickory stands, up to 9 

bird species would likely be extirpated from the 

forest. Therefore, to maintain biological diversity 

and populations of all native vertebrates, pinehardwood stands should be maintained in forests 

where they naturally occur. 

The predictions of the effects of management practices on each species are in the appendix. Generally, at least twice as many species were predicted to 

be negatively affected than positively affected for all 

combinations of treatment, time period and season 

(table 2). Combining breeding and wintering 

species, the numbers of species predicted to be 

positively affected at some time (i.e. during at least 

1 of the time periods) by clearcutting sawtimber 

and pole timber were 53 and 49 respectively and 

the numbers of species predicted to be negatively 

affected by clearcutting sawtimber and pole timber 

at some time were 85 and 80 respectively. Only 4 

species that were predicted to be affected at some 

time by clearcutting, were predicted to be positively 

affected during 1 time period and negatively affected during another. Also. almost all the species 

predicted to be affected by clearcutting were 

predicted to be affected the same way by sawtimber and pole timber clearcutting. It is worth noting 

that the predicted long-term effect of clearcutting 

sawtimber is positive for far fewer species than for 

any other treatment and time period. This implies 

that pole timber provides better habitat than sawtimber for only a very few species. 

Table 2.--Numbers of breeding and wintering bird species predicted 

to be positively affected (+), negatively affected (-), and 

unaffected (=) by clearcutting. 

Breeding Wintering 

Clearcuttxng sawtlmber 

Immediate 27 65 44 13 61 42 

Short- term 20 57 53 22 52 62 

Long- term 4 42 90 3 28 105 

Clearcutting pole timber 

Immediate 27 52 52 12 57 47 Short-term 17 48 71 20 47 69 

We found 2 published field studies of the effects of 

clearcutting on birds in pine-hardwood forests. 

Conner and others (1 979) censused breeding and 

wintering birds in a 3-year-old clearcut. a 10-yearold clearcut, a 30-year-old stand, and a mature 

stand. They found more breeding and wintering 

bird species in the mature stand than in any of the 

other stands. The number of breeding species they 

found increased with stand age. Conner and others 

(1 979) concluded that pileated woodpeckers, hairy 

woodpeckers, scarlet tanagers, red crossbills, pine 

warblers, and ovenbirds were associated with older 

stands. We predicted that clearcutting would have 

a negative effect on all these species. They also 

concluded that northern flickers, prairie warblers, indigo buntings, yellow-breasted chats, white-eyed 

vireos (Vireo arise), and field sparrows were associated with the younger stands. We predicted 

that clearcutting would have a positive effect on all 

these species except northern flickers, for which we 

predicted a negative effect and white-eyed vireos, 

which were not listed by Hamel and others (1 982) 

as commonly using southeastern pine-hardwood 

forests. 

Strel ke and Dickson (1 980) censused breeding 

birds in 2 pine-hardwood stands (30 years old) and 

adjacent clearcuts ( years old). There was no significant difference in the number of species that 

they found in the forests and the clearcuts but the 

mean number of species they found was 3.6 in 

each area. Strelke and Dickson (1980) concluded 

that yellow-billed cuckoos, blue jays, summer 

tanagers, tufted titmice, red-eyed vireos, pine 

warblers, and black-and-white warblers were associated with the older forest. We predicted that all 

these species would be negatively affected by clearcutting. They also concluded that blue grosbeaks, 

indigo buntings, yellow-breasted chats, and prairie 

warblers were associated with clearcuts, which we 

predicted would be positively affected by clearcutting. 
The greater number of bird species negatively affected by clearcutting results because sawtimber 

provides the best habitat for more bird species than 

any other successional stage, and in the absence of 

sawtimber, pole timber provides the best habitat for 

more bird species than the earlier successional 

stages. The best habitat is provided by sawtimber 

for 42 breeding bird species and 27 wintering 

species (ie. sawtimber has a better habitat rating 

than any other successional stage for these 

species), by pole timber for 1 breeding species and 

no wintering species, by the shrub-seedling successional stage for 13 breeding species and 4 wintering species, and by the grass-forb successional 

stage for 20 breeding species and 24 wintering 

species. In the absence of sawtimber, pole timber 

provides the best habitat for 47 breeding species 

and 45 wintering species, but the number of 

species does not change for the shrub-seedling and 

grass-forb successional stages. Also, sawtimber 

can provide optimal or suitable habitat for more 

than twice as many species as any other successional stage, except for wintering birds in the sapling-pole timber stage (table 1). 

There are a large number of bird species in 

southeastern pine-hardwood forests that are associated with sawimber and, to a lesser degree, 

pole timber. For many of these species sawtimber 

provides optimal habitat, and pole timber provides 

suitable or marginal habitat, but the earlier successional stages provide only marginal or unsuitable 

habitat. Therefore, to maintain biological diversity, 

a large portion of any pine-hardwood forest should 

be sawtimber. 

Considering species affected in the grass-forb and 

shrub-seedling successional stages, 5 breeding and 

3 wintering bird species were predicted to be negatively affected by the removal of snags during clearcutting. Three of the breeding species and 2 of the 

wintering species were otherwise predicted to be 

positively affected by clearcutting. The removal of 

snags probably would make clearcuts unsuitable 

habitat for these species. Thus, the removal of 

snags during clearcutting is likely to decrease the 

number of species positive1 y affected and increase 

the number of species negatively affected by clearcutting. 

Dickson and others (1 983) censused breeding birds 

in 4 plots with snags and 4 plots without snags in a 

pine-hardwood clearcut planted with loblolly pine. 

They found significantly more bird species in the 

plots with snags than in the plots without snags. 

They found red-headed, hairy, downy, and red-bellied woodpeckers, and Carolina chickadees almost 

exclusively on the plots with snags We did not 

predict the effect of snag removal during clearcutting on these species because they did not have an 

optimal or suitable habitat rating in clearcuts. The 

geographic location (Texas) or the planting of loblolly pine may have affected the habitat suitability for 

some species, and our examination of species only 

with optimal or suitable habitat ratings may have 

been too consewative. Dickson and others (1 983) 

also found that Carolina wrens, northern cardinals, 

brown-headed cowbirds, and yellow-breasted chats 

were substantially more abundant or more detectable in plots with snags. We predicted that snag 

removal would negatively affect all of these species 

except northern cardinals, for which we made no 

prediction. 

Our predictions and the study by Dickson and 

others (1 983) indicate that the removal of snags 

during clearcutting will cause the clearcut to be unsuitable habitat for several species. Therefore, when 

possible, snags should be retained during clearcutting. 

For all the successional stages considered, no 

species were predicted to be positively affected and 

a substantial number of species were predicted to 

be negatively affected immediately after burning 

(table 3). However, the short-term effect of burning 

was predicted to be positive for a large number of 

species and negative for 0 or 1 species in all the 

successional stages considered (table 3). The 

species for which the short-term effect of burning 

was predicted to be positive were those for which 

the immediate effect of burning was predicted to be 

negative or could not be predicted. These species 

all use herbaceous ground cover and/or shrubs 

which decrease immediately after burning but then 

increase. Most of the species for which the immediate effects of burning could not be predicted 

were species that use both bare soil, which increases, and herbaceous ground cover, which 

decreases. Many of these species also use shrubs 

or leaf litter, which decrease immediately after burning. Therefore, they probably would be negatively 

affected immediately after burning. 

Table 3.--Numbers of breeding and wintering bird species 

predicted to be posltlveiy affected (4). negatively affected (-1, 

and unaffected (=) by controlled burni~g; and for whlch the 

effect of controlled burning could not be predicted (7). 

Breeding Wintering 

Treatment; 

time of effect + - = ? +-=? 

Burning sawtimber 

Immediate 0 17 6 20 0 20 4 22 

Short- term 28 1 13 1 33 1 10 2 

Burning pole timber 

Imniediate 0709 01531.6 

Short- term 1302i 27052 

Burning clearcuts 

Immediate 0705 07014 

Short-term 1.0002 18003 
Pileated woodpeckers, the only species for which 

the short-term effect of burning was predicted to be 

negative, use slash, which are consumed by burning. The few species for which the short-term effect 

of burning could not be predicted also use slash. 

We found no published field studies of the effects of 

controlled burning on birds in southeastern pinehardwood forests. 

With the exception of a few species that use slash, 

the overall effect of controlled burning is likely to be 

positive for birds in pine-hardwood forests. Although a substantial number of species were 

predicted to be negatively affected immediately 

after burning, this effect would only last about a 

year and then many of these species would likely 

be positively affected for 5 to 10 years. Because 

the immediate effect of burning is negative, it would 

be best to burn areas that are as small as possible 

and to schedule burning so that adjacent areas are 

not burned during a short time period. 

Thinning 

There were many more species for which a prediction could not be made than for which a prediction 

could be made concerning thinning (table 4). Most 

of the species for which the effect of thinning could 

not be predicted feed in herbaceous ground cover 

and/or shrubs which increase, but they also feed, 

nest, or roost in the overstory and/or midstory 

canopies, which decrease. Patterns in the numbers 

of the relatively few species for which the effect of 

thinning could be predicted may not be representative of the large number of species for which 

the effect of thinning could not be predicted. 

Table 4.--Numbers of breeding and wintering bird species predicted 

to be positively affected (+), negatively affected (-), and 

unaffected (=) by thinning; and for which the effect of thinning 

could not be predicted (?). 

Breeding Wintering 

Treatment + - = ? + - = ? 

Thinning pole timber 1 O 2 13 4 3225 

Thinning sawtimber 2 11 2 28 47332 

We found 2 field studies of the effects of thinning on 

birds in southeastern pine-hardwood forests. McComb and Noble (1 980) censused birds for a year 

on a thinned plot and an unthinned plot in a pinehardwood forest in Mississippi. They detected 

about the same number of species on each plot (47 

on the thinned plot, 44 on the unthinned plot). They 

made conclusions for only 5 bird species. They 

concIuded that Carolina chickadees, yellow-rumped 

warblers, white-throated sparrows, and northern 

cardinals were positively affected by thinning and 

that red-eyed vireos were negatively affected. Their 

conclusions agreed with our predictions for northern cardinals and red-eyed vireos. We could not 

predict the effects of thinning on the other 3 

species. 

Garrison (1986) censused breeding birds in a 

thinned and an unthinned pine-hardwood stand. 

He found significantly more eastern wood-pewees, 

wood thrushes, hooded warblers, and rufous-sided 

towhees and significantly fewer downy and hairy 

woodpeckers, great; crested flycatchers, and redeyed vireos in the thinned stand than in the unthinned stand. Our predictions agreed with his 

data for hairy woodpeckers, great crested 

flycatchers, and red-eyed vireos and disagreed for 

eastern wood-pewees. We could not predict the effects of thinning on the other 4 species. Because of 

the difficulty of predicting the effects of thinning on 

avian species using habitat relationships and the 

lack of field studies, there is a great need for research on the effects of thinning on avian species in 

southeastern pine-hardwood forests. 

Fourteen breeding and 10 wintering bird species 

were predicted to be negatively affected by the 

removal of snags from sawtimber during thinning, 

and 5 breeding and 4 wintering species were 

predicted to be negative1 y affected by the removal 

of snags from pole timber during thinning. Many of 

these species require the presence of snags for 

suitable habitat, Sawtimber and pole timber are the 

only successional stages that can provide optimal 

or suitable habitat for most of these species. Therefore, the removal of snags from sawtimber and pole 

timber could extirpate some of these species from 

the area. Thus, to maintain biological diversity and 

populations of all vertebrate species, snags should 

not be removed from sawtimber or pole timber 

while thinning. 

ACKNOWLEDGEMENTS 

Funding for this study was provided by the USDA 

Forest Service and Virginia Polytechnic Institute 

and State University. We thank Lynette A. Serlin for 

her help throughout the study. 
LITERATURE CITED 

Conner, Richard N.; Via, Jerry W.; Prather, l~ine D. 

1979. Effects of pine-oak clearcutting on winter 

and breeding birds in southwestern Virginia. Wilson Bulletin 91 (2) :301-316. 

Cushwa, Charles T.; Czuhai, Eugene; Cooper, 

Robert W. [and others]. 1969. Burning clearcut 

openings in loblolly pine to improve wildlife 

habitat. Georgia Forest Research Paper. 61 : 1-5. 

Dickson, James G. 1981. Impacts of forestry practices on wildlife in southern pine forests. 

pp.224-230. In: Proceedings, increasing forest 

productivity. SAF Publication 82-01 . Society of 

American Foresters, Bethesda, MD. 

Dickson, James G.; Conner, Richard N.; Williamson, J. Howard. 1983. Snag retention increases 

bird use of a clear-cut. Journal of Wildlife Management 47(3):799-804. 

Garrison, Barry A. 1986. Avian population densities, 

habitat use, and foraging ecology in thinned and 

unthinned hardwood forests in southwestern Virginia. Blacksburg: Virginia Polytechnic l nstitute 

and State University. 133 pp. Thesis. 

Hamel, Paul B.; LeGrand, Harry E., Jr.; Lennartz, 

Michael R. [and others]. 1982. Bird-habitat 

relationships on southeastern forest lands. Gen. 

Tech. Rep. SE-22. Asheville, NC: U.S. Department 

of Agriculture, Forest Service, Southeastern 

Forest Experiment Station. 41 7 pp. 

Hooper, Robert G. 1978. Cove forests: Bird communities and management options. pp. 90-97. In: 

Proceedings of the workshop management of 

southern forests for nongame birds. 1978 

January 24-26; Atlanta, GA. Gen. Tech. Rep. SE14. Asheville, NC: U.S. Department of Agriculture, 

Forest Service, Southeastern Forest Experiment 

Station. 

Johnston, David W.; Odum, Eugene P. 1956. Breeding bird populations in relation to plant 

succession on the Piedmont of Georgia. Ecology 

37:50-62. 

Landers, J. Larry. 1987. Prescribed burning for 

managing wildlife in southeastern pine forests. 

pp. 19-27. In: Managing southern forests for 

wildlife and fish: A proceedings. 1987. Gen. Tech. 

Rep. SO-65. New Orleans, LA: U.S. Department 

of Agriculture, Forest Service, Southern Forest Experiment Station. 

Lewis, Clifford E.; Grelen, Harold E,; Probasco, 

George E. 1982. Prescribed burning in southern 

forest and rangeland improves forage and its use. 

Southern Journal of Applied Forestry 6(1): 19-25. 

McComb, William C. 1982. Forestry and wildlife 

habitat management in central hardwoods. Journal of Forestry 80(8) :490-492. 

McCornb, William C.; Noble, Robert E. 1980. Small 

mammal and bird use of some unmanaged and 

managed forest stands in the mid-south. Proceedings of the Annual Conference of the 

Southeastern Association of Fish and Wildlife 

Agencies 34:482-491. 

Odum, Eugene P. 1950. Bird populations of the 

Highlands (North Carolina) Plateau region in relation to plant succession and avian invasion. 

Ecology 31 :587-605. 

O'Halloran, Kathleen A.; Blair, Robert M.; Alcaniz, 

Rene [and others]. 1987. Prescribed burning effects on production and nutrient composition of 

fleshy fungi. Journal of Wildlife Management 

51 (1 ) 1258-262. 

Resler, Rexford A. 1972. Clearcutting: Beneficial 

aspects for wildlife resources. Journal of Soil and 

Water Conservation 27(6):250-254. 

Shugart, Herman Henry; James, Douglas. 1973. 

Ecological succession of breeding bird populations in northwestern Arkansas. Auk 90:62-77. 

Strelke, William K.; Dickson, James G. 1980. Effect 

of forest clear-cut edge on breeding birds in east 

Texas. Journal of Wiidiife Management 44(3):559- 

567. 

Van Lear, David H.; Johnson Von J. 1983. Effects of 

prescribed burning in Southern Appalachian and 

Upper Piedmont forests: A review. Forestry Bulletin 36. Clemson, NC: Clemson University, 

College of Forest and Recreation Resources, 

Department of Forestry. 8 pp. 

Wood, Gene W.; Niles, Larry; 1978. Effects of 

management practices on nongame bird habitat 

in longleaf-slash pine forests. pp. 40-49. pp. 90- 

97. In: Proceedings of the workshop 

management of southern forests for nongame 

birds. 1978 January 24-26; Atlanta, GA. Gen. 

Tech. Rep. SE-14. Asheville, NC: U.S. Department 

of Agriculture, Forest Service, Southeastern 

Forest Experiment Station. 

Zeedyk, William D.; and Evans, Keith E. 1975. Silvicultural options and habitat values in deciduous 

forests. pp.115-127. In: Proceedings of the symposium on management of forest and range 

habitats for nongame birds. 1975 May 6-9; Tucson, AZ: Gen. Tech. Rep. WO-1. Washington, 

D.C.: U.S. Department of Agriculture, Forest Service. 
Appendix.--Predicted effects of clearcutting, burning, and 

G clearcuttingb Burning Thinning d 

Turkey vulture 

Cathartes aura 

Black vulture B...-=-- ? + + ?=?= 

W--=-.- ?+?4 ?=?= 

American swallow-tailed kite B - - - = = 

Elmoides forficatus wL===== 

Mississippi kite B--.-== 

Ictinia mississippiensis W = = = = = 

Sharp-shinned hawk B-.-.--- ? + ? = 

Accipiter striatus 

Cooper's hawk 

A. cooperii 

Red-tailed hawk 

Buteo jamaicensis 

Broad-winged hawk 

, B. platypterus w===== 

Rough-legged hawk B===== 

B. lagopus W+==+== ? + 

Golden eagle B===== 

AquiPa chrysaetos pj+==+= 

Bald eagle B---.-.-.=. 

w--.--.- 

Northern harrier B===== 

Circus cymeus 

American kestrel 

Falco sparverius 

Ruffed grouse 

Bonasa umbellus w--=-.- ? +? + ?=?= 

% = breeding habitat, W = wintering habitat. 

b~umbers represent age class and time of effect: 1 = sawtimber/ 

immediate, 2 = sawtimberlshort-term, 3 = sawtimberllong-term, 

4 = pole timberlimmediate, 5 = pole timber/short-term, 6 = snag 

removal/immediate, 7 = snag removalfshort-term. 

G Numbers represent age class and time of effect: 1 = sawtimber/ 

immediate, 2 = sawtimber/sbort-term, 3 = pole timberlimmediate, 

4 = pole timbes/short-term, 5 = clearcut/immediate, 6 = 

glearcut/short-term. 

1 = sawtimber, 2 = snag removal from sawtimber, 3 = pole timber, 

4 = snag removal from pole timber, 

e= indicates the species would be negatively affected; +, 

positively affected; =, unaffected, ?, em not predict; blmk, 

the species had a marginal or unsuitable habitat rating in that 

successional stage. 
Clearcutting Burning Thinning 

Species ~12345671234561234 

Northern bobwhite B++=++== ? + 

Colinus virginianus w++=++== ? + 

Ring-necked pheasant B+==+== ? + 

Phasianus colchicus w+==+== ? + 

Wild turkey B----- ? + ? = 

Meleagris gallopavo w-.-.=-- ? +? + ?=?= 

American woodcock B----- ? + + = 

Scolopax minor w---== ? + + = 

Upland sandpiper B+==+== - + 

Bartramia longicauda w===== 

Rock dove B+==+= 

Columba livia w+==+= 

Mourning dove B=++-===?+?+?+?=?= 

Zenaida macroura w=======?+?+?+?=?= 

Common ground dove B=+==+ 

Columbina passerina w++=++ 

Yellow-billed cuckoo B--=-- 

Coccyzus americanus w==--- --- 

Black-billed cuckoo B--=-- 

C. erythropthalmus w===== 

Common barn-owl E)++=++- ?? 

Tyto alba w++=++- ?? 

Eastern screech-owl B----.- ? + ? - 

Otus asio w----- ? + ? - 

Great horned owl B---== ? + ? = 

Bubo virginianus w----- ? + ? = 

Long-eared owl B----- ? + 7 = 

Asio otus 

Short-eared owl 

A. flammeus w+==+= 

Northern saw-whet owl B==--- --- 

Aegolius acadicus w-==-= 

Chuck-will's widow B---.-- -=-= ---- 

Caprimulgus carolinensis W - - = - - -=-= ---- 

Whip-poor-will B----- -=-= ---- - - - - 

C. vociferus -=-= ---- 

Ruby-throated hummingbird B - = = - = 

Archilochus colubria w===== 

Northern flicker B----- ? + ? - 

Colaptes auratus w---== ? + ? - 

Pileated woodpecker B----- - - ? - 

Dryocopus pileatus w----- - - ? - 

Red-bellied woodpecker B-----. - = - - 

Melanerpes carolinus w----- - = - - 

Red-headed woodpecker B--=-- 

M. erythrocephalus Ma-=-- 
Clearcutting Burning Thinning 

Species HI2345671234561234 

Yellow-bellied sapsucker B===== 

Sphyrapicus varius w-----. -+-+ ?-?- 

Hairy woodpecker B----- - - - - 

Picoides villosus w----- - = - - 

Downy woodpecker 

P. pubescens 

Red-cockaded woodpecker 

P. borealis 

Eastern kingbird 

Tyrannus tyrannus 

Great crested flycatcher 

Mviarchus crinitus 

Eastern phoebe 

Sayornis phoebe 

Acadian flycatcher 

Empidonax virescens 

Eastern wood-pewee 

Contopus virens 

Horned lark 

Erem~~hils ahestris 

Bank swallow 

Riparia riparia 

Barn swallow 

Hirundo rustica 

Cliff swallow 

H. pyrrhonota 

Purple martin 

Prome subis 

Blue jay 

Cyanocitta cristata 

Common raven 

Corvus corax 

American crow 

C. brachyrhynchos 

Fish crow 

C. ossifragus 

Black-capped chickadee 

Parus atricapillus 

Carolina chickadee 

P, carolinensis 

Tufted titmouse 

P. bicolor 

White-breasted nuthatch 

Sitta carolinensis 

Red-breasted nuthatch 

S, canadensis 
Clearcutting Burning Thinning 

Species 

Brom-headed nuthatch 

S. nusilla 

Brown creeper 

Certhia mericma 

House wren 

Wi 

Bewick's wren 

Thryommes bewickii 

Carolina wren 

Thyothorus ludovicianus 

Northern mockingbird 

Mimus polyglottos 

Gray catbird 

Dumetella carolinensis 

Brown thrasher 

Toxostoma rufum 

American robin 

Turdus migratorius 

Wood thrush 

Hylocichia mustelina 

Hermit thrush 

Catharus guttatus 

Eastern bluebird 

Sialia sialis 

Blue-gray matcather 

Polioprila caerulea 

Golden-crowned kinglet 

Reffulus satrapa 

Ruby-crowned kinglet 

R. calendula 

Cedar waxwing 

Bombycilla cedrorum 

European starling 

Yellow-throated vireo 

Vireo f lavi f rons 

Solitary vireo 

V, solitarius 

Red-eyed vireo 

V, olivaeeus 

Black-md-white warbler 
Clearcutting Burning Thinning 

Species ~12345671234561234 

Golden-winged warbler B=++-= 

Vermivora shrysoptera w===== 

Blue-winged warbler B=+==+ 

V. pinus 

Orange-crowned warbler 

V. celata 

Northern parula B----- 

Parula americana 

Yellow-rumped warbler 

Dendroica coronata w--=-- =?+?+ 

Black-throated green warbler B - - - - - - - - - 

D. virens 

Yellow-throated warbler 

D. dominica w----- - = 

Chestnut-sided warbler B-+=-+ = 

D. pensylvanica 

Pine warbler 

D. Dinus 

Prairie warbler 

D. discolor 

Palm warbler 

Ovenbird 

Seiurus aurocapillus 

Louisiana waterthrush 

S. motacilla 

Kentucky warbler 

Oporornis formosus 

Common yellowthroat 

Geothlypis trichas 

Yellow-breasted chat 

Icteria virens 

Hooded warbler 

Wilsonia citrina 

House sparrow 

Passer domesticus 

Bobolink 

Dolichonvx orvzivorus 

Eastern meadowlark 

Sturnella mama 

Red-winged blackbird 

Agelaius phoeniceus 

Rusty blackbird 

Euphagus carolinus 

Brewer's blackbird 

E. cyanocephalus 
Clearcutting Burning Thinning 

Species ~12345671234561234 

Common grackle B--=-- ?+?+ ?=?= 

Quiscalus quiscula w-.-=-- 

Brown-headed cowbird B-==-= -?+?+ + - + - 

Molnthsus ater W--=-- 

Scarlet tanager 

Summer tanager 

P. rubra 

Northern cardinal 

Cardinalis cardinalis 

Blue grosbeak 

Guiraca caerulea 

Indigo bunting B=+==+ = 

Passerina cyanea w===== 

Dickcissel B+==+= 

Spirza americana w===== 

Evening grosbeak B===== 

Coccothraustes vespertinus W - - - - - ? + 

Purple finch B=-.===. 

w----- -+-+ 

Mouse finch B===== 

C. mexicanus w++=++ 

Pine siskin B===== 

Carduelis pinus w----= =?+?+ 

American goldfinch B=+==+ 

C. tristis w++=++== ? + 

Red crossbill B===== 

Loxia curvirostra w--=-.- 

Rufous-sided towhee B-++-= =-+-+ ?=?= 

Pipilo erthrophthalmus W-++-= =--+-+ +=+= 

Savannah sparrow B+==+== - + 

Passerculus sandwichensis W + = = + = = - + 

Grasshopper sparrow B+==+== - + 

Ammodramus savannarum w++=++= - + 

Henslow's sparrow B+==+= 

A, henslowii w+==+= 

Le Conte's sparrow B===== 

A. leconteii w+==+== 

Vesper sparrow B+==+= 

w+==+== 

B++=++ = 

w++=++ 

B===== 

w--.--=: =?+?+ 

B===== 

W++=+i"= - + 
Clearcutting Burning Thinning 

Species ~12345671234561234 

Chipping sparrow B===== 

S. passerina w===== 

Field sparrow B++=++==: - + 

S, pusilla W++=++== - + 

mite-crowned sparrow B===== 

Zonotrichia leucophrys w++=++= ? + 

White-throated sparrow B===== 

Z, albicollis w--=-- -+-+ ?=?= 

Fox sparrow B===== 

Passerella iliaca w----- -+-+ ?=?= 

Swamp sparrow B===== 

Melospiza georgiana w+==+= 

Song sparrow B=+==+ 

M. melodia w++=++= - + 

GROW AND YIELD 

Moderator: 

William L, Hafley 

Department of Forestry 

North Carolina State University 

VOLUME GROWTH OF PlNE AND HARDWOOD IN 

UNEVENAGED LOBLOLLY PlNE - UPLAND HARDWOOD 

MlXTURES 

Robert M. Farrar, Jr., Paul A. Murphy, and Daniel J. ~educ' 

,-Results are reported from an exploratory investigation of stand-level periodic volume 

growth of uneven-aged mixed loblolly pine Wfaeda L.) - upland hardwood stands on good 

sites in southeastern Arkansas. A restricted set of replicated obsewations was extracted from an 

extensive CFI database involving varying pine-hardwood mixtures to form an array of plots with 

different levels of pines and hardwoods. Anaiysis was conducted of the 5-year periodic annual 

increment of the pine, the hardwood, and the total (pine plus hardwood) in relation to the stand 

density of the pine and hardwood components. Results show that at low to moderate pine basal 

area levels, an added hardwood component increases total stand growth but decreases total 

growth at higher pine levels, There seems to be little or no economic justification for mixed stands 

based on these growth predictions and current stumpage prices. The implications of these results 

and other factors regarding mixed stand management are also discussed. 

INTRODUCTION 

The information base on the growth of mixed 

southern pine - hardwood stands is quite limited 

and that for uneven-aged stands is particularly 

restricted. Most of the information deals with evenaged stands. Although the principles of species interactions in mixed stands are probably 

fundamentally similar in both even- and unevenaged stands, the degree of the effect of one species 

upon another wiii probably be somewhat different in 

the two situations. 

The general successisnal trend in the dominant 

woody vegetation on the southern uplands is 

toward hardwoods ultimately replacing pine unless 

the trend is interrupted or arrested by disturbances 

such as windstorms, fire, or forest management. 

Our southern pineries existed in the past essentially 

because catastrophes, principally wildfire, occurred 

at varying intervals and intensites over time and 

favored the l ig ht-seeded pioneering pines. Since 

we no longer allow fires to burn unchecked, the successional trend under these conditions is for 

hardwoods to generally invade pine stands at some 

stage of development and to eventually dominate 

without intervening treatment to favor pines. If our 

major economic interest is in pines, then the 

hardwoods must be kept at some tolerable level. 

Most investigations on the effects of hardwoods on 

pine growth have dealt with the impacts of 

hardwoods overtopping or threatening to overtop 

pine regeneration in even-aged stands (Russel 

1963, Clason 1978, Michael 1980, Hebb 1981 ) and 

early grovvth rates of pine stands are directly related 

to the intensity of hardwood control during stand establishment. Little information exists on the effects 

'Research Foresters and Computer Specialist, Southern 

Forest Experiment Station, Monticello. AR, in cooperation 

with the Department of Forest Resources and the Arkansas Agricultural Experiment Station, University of Arkansas at Monticello. 

of hardwoods on pines in older stands. Some 

studies have shown a positive response of overstory 

pines to hardwood removal (Grano 1970, Pienaar 

and others 1983, Cain and Yaussy 1984). Burkhart 

and Sprinz (1984) show that as the percentage of 

hardwoods in the total stand increases in loblolly 

pine plantations, the survival, growth, and yield of 

the pine decreases. In even-aged shortleaf pine 

(Pinus echinata Mill.) stands, hardwood control increased growth rates of pines, particularly in dry 

years (Rogers and Brinkman 1965, Bower 1968). 

Grano (1 970) has shown in uneven-aged loblollyshortleaf pine stands that hardwoods can reduce 

the radial increment of pines by 30 to 40 percent in 

dry years. Other studies have not shown such 

responses (Russel 1961, Cain 1985, Boyer 1987). 

There may be a site-dependent threshold for 

hardwood density below which there is no appreciable effect of the hardwoods on the pine overstory 

and, from limited observations, the level appears to 

vary between about 10 to 30 square feet of basal 

area per acre (Boyer 1986). The level is probably 

toward the lower end for dry years and sites. Once 

a satisfactory pine sapling stand is established, 

there may be no strong economic reason to reduce 

hardwoods below this threshold during a rotation. 

However, it might be beneficial in reducing site 

preparation costs when the regeneration period is 

again reached. In uneven-aged pine stands the 

need to periodically secure regeneration and the 

restricted stand density range suitable for selection 

management are likely to call for a different strategy. 

This paper deals with the periodic annual increment 

(p.a.i.) in merchantable cubic feet observed on a 

set of continuous forest inventory plots in natural 

stands in southeastern Arkansas. The stands are 

uneven-aged and composed principally of loblolly 

pine with varying admixtures of upland hardwoods 
composed mostly of oaks ( sgS. The purpose is to present information on the contribution of 

the pine and hardwood components to the total 

stand growth and to foster some appreciation of the 

contribution of the hardwoods in uneven-aged pine 

stands. 

The inventory data come from 1/5-acre permanent 

plots located in uneven-aged loblolly-shortleaf pine 

stands with varying densities of pine and hardwoods on the lands of the Potlatch Corporation in 

southeastern Arkansas. The stands containing the 

plots have been periodically cut under a selection 

system, The site index is generally 80 to 90 feet for 

loblolly (base age 50 years). However, no age data 

are available. These plots were inventoried in 1966, 

1971, and 1976 affording information on two 5-year 

growth periods. Each plot tree in the 5-inch class 

and larger was positively identified and the records 

included species, dbh to the nearest 0.1-inch, and 

tree history. 

Merchantable cubic-foot volume and basal area 

were calculated for each tree. Tree volumes were 

calculated using local volume functions fitted to 

local tables for pine and hardwoods which contained average volumes per 2-inch dbh class. All 

volumes are in terms of merchantable cubic feet, 

outside bark (o. b.), for trees with dbh 4.5 inches, to 

a 4-inch, o.b., top. Stump heights were 1/2-foot for 

sub-sawtimber (dbh 9.5 inches) and 1 -foot for sawtimber (dbh 9.5 inches). The tree volume functions 

fined by least squares are: 

n = 11. R2 = .9997, RMSE = 1.113 

n = 11, FI2 = 9997. RMSE = ,869 

where 

PVol .= pine cubic-fast volume per tree 

HVer - hardwood cubic-foot volume per tree 

D =. tree dbh in inches 

n - number of 2-inch dbh classes 

FI2 = coefficient of determination 

RMSE - root mean square error 

Vsiurnes and basal areas were summed for each 

plot on an acre basis and the p.a.i. in volume was 

calculated for each plot for each of the two growth 

periods. The plots were then screened with the following restrictions to obtain a homogenous data set 

for analysis that contained a minimum amount of extraneous variation: 

1 . l nitial pine basal area is > 0. 

2. Initial hardwood basal area is 5 50 percent 

of the total basal area. 

3. Basal area of pines other than loblolly is 

6 10 percent of the initial total basal area. 

4. Basal area of oaks is 2 50 percent of the initial hardwood basal area. 

5. Mortality during a period is r 10 percent of 

the initial total basal area. 

6. lngrowth of pine or hardwood during a 

period is 2 10 percent of the initial basal area 

for pine or hardwood, respectively. 

7. Periodic annual increment of pine or 

hardwood during a period is 2 0. 

Although the growth values are actually net, we are 

essentially dealing with survivor cubic-foot volume 

p.a.i. of pine-hardwood stands with up to 50 percent of the density in hardwoods. Further, the 

hardwood density is at least 50 percent oak. This 

screening of several hundred plot observations 

resulted in selecting 58 observations on p.a.i. distributed by basal area of pine and basal area of 

hardwood as shown in table 1. No more than four 

replications per cell were chosen in an effort to extract a controlled experiment from uncontrolled 

data. The mean, minimum value, and maximum 

value for the variables and restrictions are shown in 

table 2. In this analysis data set, the following 

proportions by numbers of trees occur in the 

stands at the start of the 5-year growth periods: 

1. 99 percent of the pines were loblolly and only 1 

percent were shortleaf. 

2. 67 percent of the pines were poletimber (2 9.5 

inches dbh) and 33 percent were sawtimber ( > 9.5 

inches dbh). 

3. 72 percent of the hardwoods were oaks composed of 44 percent red oaks and 28 percent white 

oaks. 

4. The red oaks were principally southern red oak 

(111. Michx.), willow oak (Q. L.), and 

water oak (Q. L.) while the white oaks were 

principally po a Wangenh.) and 

white oak (Q. 3. 

5. 18 percent of the hardwoods were gums, principally sweetgum ( L.), and 

the remaining 10 percent were miscellaneous hardwoods. 

6. 71 percent of the hardwoods were poletimber 

and 29 percent were sawtimber. 
Table 1.--Distribution of growth observations by pine and hardwood 

basal area classes. Analvsls 

Hardwood Basal Area Class 

pine ~~~1 sq, ft,/ac. ------------------.. Area Class 

sq. ft./ac. 0 10 20 30 40 All 

The analysis consisted of regression analysis to relate the pine, hardwood, and total (combined pine 

+ hardwood) p.a.i. to the pine and hardwood basal 

area at the start of the growth period. We investigated and evaluated several systems of linear 

equations in which pine, hardwood. and total p.a.i. 

are each predicted. We also tried non-linear systems in which the total p.a.i. is predicted, pine p.a.i. 

is predicted as a proportion of the total p.a.i., and 

hardwood p.a. i. is obtained by subtraction. We 

finally converged on the following system of nonlinear models due to reasonable trends and goodness of fit: 

Totals 32 12 5 5 4 58 

PPAl = fl (PBA, HBA) 

HPAI = f2(PBAl HBA) 

Table 2.--Means and limits for variables and restrictions. 

I tern n Mean Minimum Maximum 

Pine p.a.i. 58 107.3 

Hardwood p.a.i. 58 11.9 

Total p.a.i. 58 119.1 

Pine basal area 58 59.4 

Hardwood basal armi 58 8.9 

Percent of total basal 58 0.7 

area in shortleaf pine 

Percent of total basal 58 13.1 

area in hardwood 

Percent of hardwood 32a 13.9 

basal area not oaks 

Mortality as percent of 58 1.6 

total basal area 

Pine ingrowth as percent 58 2.4 

of pine basal area 

Hardwood ingrowth as pct. 32a 2.6 

of hardwood basal area 

a~wenty-six observations had no initial hardwood basal area. 

Table 3. --Fit statisticsa for prediction equations. 

Equation n Mean Bias FI RMSd MABSd 

TPAl = PPAl + HPAI (5) 

where 

PPAl = 5-year pine p.a.i., cu. ft./ac./yr. 

fl , f2 = functions of similar form 

PBA = pine basal area, sq. ft./ac. 

HBA = hardwood basal area, sq. ft./ac. 

HPAl = 5-year hardwood p.a.i., cu. ft.lac./yr. 

TPAI = total p.a.i. = (PPAI + HPAI) 

Equations 3 and 4 in this model set were formulated 

and fitted via non-linear least-squares utilizing 

"seemingly unrelated regressiont' procedures (SAS 

1984). Solution of equation 5 is obtained by summing fitted equations 3 and 4. All three equations 

were then evaluated regarding goodness-of-fit. 

RESULTS AND DISCUSSION 

The fitted equations for the system are as follows: 

6 (PPAI) 58 107.3 .3652 .6696 30.26 22.78 PPAI = 2.70100(p~~)e{A'~ (6) 

~(HPAI) 58 11 .g -. 1688 ,8725 5.13 3.24 where: {A) = -0.0046892(PBA) -0.0085694(HBA) 

8 (TPAI) 58 119.1 ,1964 .a28 31.15 23.62 HPAI = 4.24869(~~~)eiB!, (7) 

a n = number of values 

p = predicted value 

o = observed value 

Mean = Z(o)/n 

Etas = Z(p-o)tn 

FI = 1 - [2(p-0j~i2(0-Z(0fin)~] 

RMS~ = [(~(p-o)~)/n]"~ 

MABSd = Z (p-o;!n 

where: (6) = -0.0087526(PBA) -0.031 3041 (HBA) 

TPAl = PPAl + HPAi (8) 

The goodness of fit statistics for this set are shown 

in table 3. The amount of variation in the dependent variables accounted for by the system is not outstanding but is probably about as much as could 
be expected from such a database not controlled 

for research purposes. The unusually good fit 

index (FI) For HPAI is partly due to 18 of the 58 obsewations being zero and thus having zero deviations from the predicted value. The lower RMSB for 

HPAt reflects the lower p.a.i, of the hardwood component compared to the pine. 

The predicted response of pine and hardwood for 

typical selection stand densities is shown in table 4. 

Wa see that increasing hardwosd basal area 

decreases pine p.a.i. at any pine density level. This 

is similar to the response found by Burkhart and 

Sprinz (1 984) in loblolty pine plantations. In a like 

manner, hardwood p.a.i. declines wkh increasing 

pine basal area at any hardwood density level. 

Both responses are also illustrated in figures 1 

and 2. 

Except at the lowest HBA levels, the eflect of the 

pine basal area on pine p.a.i. is somewhat more 

than directly proportional. For example, in table 5 a 

total basal area sf 60 square feet per acre is partitioned into varying proportions of pine and 

hardwood basal area. Here, we see that where 

PBA is 90 percent of TBBA, the PPAI is 89 percent of 

VAl. But, where PBA is 70 percent of TBA, the 

PPAI is 73 percent of TPAI. As the PBA decreases 

to 50 percent, its contribution to TPAI increases to 

58 percent. Also, the eNect of hardwood basal area 

on hardwosd p.a.i. peaks at about 30 square feet 

(figure 2) at any pine basal area level and does not 

vary much above 28 square feet of HBA. 

The eflect of pine and kardwood basal area on total 

p.a.i. is shown graphically in figure 3. At low pine 

densities the hardwood density contributes to total 

groMh. But, as PBA increases above about 50 to 

80 square feet, I4BA reduces the total growth. At 

the upper pine densities total growth reduction increases as MBA increases. These responses imply 

that, at lower pine densities, the pine component 

does not fully utilize the site's resources and the add it ionas hardwood component makes a net cont ri bution to total groMh but pine growth alone decreases 

(table 4). In contrast, at the upper pine density 

levels, adding hardwood density results in a net 

competitive effect and the dotal groMh is reduced. 

The reduc"6isn in total grovvth here is directly related 

to the hardwosd density level. 

An interesting aspect sf these relationships is the impiied growlhidensity 8Niciencies. If we define efficiency as the ratio of p.a.1. to basal area and plot it 

on the ratio of; pine basal area to total basal area, 

we gel the eNiciency trends depicted for pine, 

hardwood, and total in figures 4 through 6. Each 

figure shows the calculated efficiency as ploned for 

three levels of totat basa! area normally encountered in selection stands - 45, 60, and 75 

square feet. In all cases the lowest total basal area 

oi . , . , . , . , . , . , . , . 1 . , . , . F 

10 20 30 40 50 60 70 80 90 100 110 120 

Pine basal area 

t4ordwood basal area - 0 ----- 10 -- ---- 20 

30 --- 40 

Figure 1 .--Pine p.a.i. in relation to pine basal area, 

by hardwood basal area level (HARDBA). 

Pine basal area 

Hardwood basal area - 0 ----- 10 -- ---. 20 

30 --- 40 

Figure 2.--Hardwood p.a.i. in relation to pine basal 

area, by hardwood basal area level (HARDBA). 

20 ' 

O~.,.,.,.'.,.,.,.,.l.,.r 

10 20 30 40 50 60 70 80 90 100 110 120 

P~ne basal area 

Hardwood basal area - 0 ----- 10 -- ---- 20 

30 --- 40 

Figure 3.--Total p.a.i. in relation to pine basal area, 

by hardwood basal area level (HARDBA). 
7 01. . . , . . , . . r 

C 5 0 6 0 7 0 3 13 9 10 

Rattc of prne ba to total ba 

Tctai Basa! Area - 45 square feet ----- -- 513 square feet 

75 square feet 

Figure 4.--Pine growth efficiency in relation to the 

proportion of pine in the total basal area, by three 

total basal area levels. 

Ratio of pine ba to total ba 

Total Basal Area - 45 square feet ----- -- 60 square feet 

75 square feet 

Figure 5.--Hardwood growth efficiency in relation to 

the proportion of pine in the total basal area, by 

three total basal area levels. 

Ratio of pine ba to total ba 

Totai Bosai Area - 45 square feet ----- 60 square feet -- 75 ssuare feet 

Figure 6.--Total growth efficiency in relation to the 

proportion of pine in the total basal area, by three 

total basal area levels. 

class has the highest efficiency and ail efficiencies 

increase as the proporlion of pine basal area increases. For pine and the total stand the increase 

in efficiency is gradual as the propofiion of pine 

basal area increases but for hardwood the increase 

is relatively steep. EPFiciencies range from about 4 6 

to 2.2 cubic feet per square foot for pine, from 

about 1 O to 2 9 for hardwood and from about 1.3 

to 2.2 for total At higher proportions of pine basal 

area, hardwood eiiiciency greatly exceeds that of 

pine, indicating that the hardwoods are much more 

tolerant in this situation. Although hardwood efficiency is greatest at higher proporlions of pine 

density. this does not result in greatly increasing 

total efficiency (figure 6). Hardwood levels are so 

low at higher pine proporlions that total etficiency 

tends to become asymptotic when the pine basal 

area proportion is above 80 to 98 percent. 

Table 4. --Predicted p. a. i . by pine, md hardwood density levels. 

PBA M3A PPAI WAX WAX 

These growth predictors can be used to obtain 

crude estimates of the monetary impact of pinehardwood mixtures. For example, look al the situation in table 4 where a stand has 60 square feet of 

TBA with PBA varying from 100% to 50%. Assume 

that a cord contains 90 cubic feet (0.b.) and that 

stumpage is $15 per cord for pine and $5 per cord 

for hardwood. The resulting scenario illustrated in 

table 5 shows that 10 percent hardwood decreases 

the total stumpage only by a dollar or two, but 50 

percent hardwood decreases stumpage by nearly 

half. Even if stumpage prices were equal for pine 

and hardwood, the mixed stand value gr0wl.h wili 

be less than that for pure pine. However, in some 

cases (table 4) equal stumpage prices could result 

in a slight monetary advantage if total basal areas 

are in the sustainable range under selection 

management. 
Table 5.--Predicted p.a.i. for 60 square feet of total basal area 

composed of varying percentages of pine and hardwood basal area. 

PBA HBA PPAI, HPAI TPAI 

---------------- ------------------- cu. ft./ac./yr. 

100 0 1 00 0 122 

90 10 89 11 121 

80 20 80 20 116 

70 30 7 3 27 110 

60 40 66 34 102 

50 50 58 41 9 3 

OTHER CONSIDERATIONS 

Aside from the growth and stumpage aspects, a 

number of other considerations must be dealt with 

in managing mixed pine-hardwood stands. It is 

probably true that if we wish to expend sufficient 

energy and ignore costs we could manage almost 

any conceivable mixture of pines and hardwoods. 

But, we also think that where economical timber 

production is the primary goal, on suitable uplands 

it will be best to manage pine in pure stands and 

any desired hardwood component will best be 

managed separately as inclusions of whatever size 

is deemed suitable. These could be patches of a 

few tenths to an acre or so, the borders of 

drainages, andlor the st ream bottoms. This allocation may complicate inventory and record-keeping 

but will largely prevent long-term management 

problems. In general, hardwoods should be grown 

on the sites best suited to them, which will usually 

be the minor to major stream bottoms in the 

Southern Coastal Plain. Whether pine or hardwood 

is to be managed, we think that both will be most efficiently managed as essentially pure stands due to 

the silvical nature of these species groups, management considerations, and general successional 

trends. 

In selection or uneven-aged pine management, it 

seems imperative that stands be kept as "pure" as 

feasible. The basal area "window" for pine selection 

management is fairly narrow - about 45 to 75 

square feet - and all needs to be in pine for adequate production. The addition of a hardwood component to the pine component may push the 

density above the level where development of pine 

regeneration and recruitment into the stand can be 

sustained. This level has not been well quantified 

but observations strongly suggest that it is no 

higher than 80 square feet at the end of a cutting 

cycle for uneven-aged loblolly pine stands in 

southeastern Arkansas. Until this level is better 

defined, the safest option is to allow practically no 

hardwoods in uneven-aged pine stands. 

If the hardwood component is added in place of 

pine, the pine growing stock is reduced, which 

generally lowers total production and profits. Furthermore, hardwood density, due to its much 

denser shade, generally retards pine reproduction 

more than an equivalent amount of pine density 

Wahlenberg 1960). Pine will regenerate and 

develop to some extent under the shade of a given 

moderate pine basal area but not to any useful extent under the shade of an equivalent basal area of 

hardwood. This is based on obsewation and implied by work by Wahlenberg (1948) and Bormann 

(1956). At every cutting cycle, there is essentially a 

need to obtain some pine regeneration to sustain 

the system. If hardwoods are continually present 

they have the potential to interfere with pine 

reproduction and capture pine growing space. 

There is also the danger that a seemingly small 

amount of hardwood in a selection stand may, by 

default, increase to a major proportion simply because the volume and growth is not sufficient for it 

to be operationally reduced at each cutting cycle. It 

may take two or three cutting cycles to build 

enough hardwood volume for an operational cut 

and during this time it can seriously affect both pine 

growth and reproduction if some action, such as a 

periodic non-commercial reduction, is not taken. 

For example, we see in table 6 that 6 square feet of 

hardwood produces a p.a.i. of only 13 cubic feet. 

At this rate, if 2 cordslacre is a minimum operable 

cut, it will take about 14 years to produce a commercial cut and leave the initial hardwood density. 

There might be some small increase in hardwood 

production due to increasing hardwood density 

during this period but this would likely be offset by 

reduced pine production and, more importantly, increased interference with pine reproduction. 

Table 6.--Estimated stumpage valuea of the p.a.i. for a stand 

with 60 square feet of total basal area composed of varying 

proportions of pine and hardwood basal area. 

PBA HBA PPA I HPAI TPAI VALUE 

------ cu. ft./ac.!yr ----- dollars 

a Assuming 90 cubic feet, o.D., per cord, $15 per cord for 

pine, $5 per cord for hardwood. 

The even-aged situation is not quite so critical because here the hardwoods can be dealt with more 

easily. The general principle that the hardwoods 

will not grow as well as pines on upland Coastal 

Plain sites still holds. Thus, mixtures of reasonable 

densities will not grow as much as pure pine at the 

same densities. But, because the densities in evenaged stands are usually maintained at higher levels 

than in uneven-aged stands, one can tolerate a certain amount of hardwood and still maintain satisfactory pine densities and production. For example, 
10 to 20 square feet of hardwood might be acceptable in even-aged stands containing 60 to 100 

square feet of pine. 

Another major reason why mixed even-aged stands 

are more acceptable is that there is no need for periodically recurring pine regeneration. At the end of 

each rotation, necessary steps are taken during the 

regeneration period to insure an acceptable level of 

pine reproduction, a tolerable level of hardwood 

reproduction is also accepted, and regeneration is 

not a concern again until the end of the rotation. 

The two components grow up together and, 

depending upon growth and values, are thinned as 

desired during the rotation and harvested at the 

end. Some hardwoods may actually act as valuable trainers to the pines and improve their pruning 

and form (Paul 1933) although at a cost of reduced 

pine production. Also, some landowners may accept even-aged mixed stands containing a relatively 

large hardwood component because they cannot afford expensive site preparation or pine release 

work. They may not get maximum production or 

returns but they will not have large investments and 

can exercise this option, which may not be available in uneven-aged stands due to adverse effects 

of hardwoods on pine regeneration. 

Aside from taking up pine growing space in evenaged stands, a hardwood component can interfere 

with area-wise stand treatment prescriptions such 

as herbicide treatments for cleanings and weedings 

and prescribed fire use to control undesirable 

vegetation. In cleanings or weedings, the individual 

desirable hardwood stems will need to be marked 

to prevent their destruction and treatments will have 

to be stem-wise. It will be difficult to burn and discriminate between desirable hardwoods and undesirable brush. Fires are likely to be irregular in 

intensity and coverage and they may promote 

decay in the desired hardwood component. Also, 

the amount of hardwood may be so small and dispersed that it will not even be an asset to non-timber values. Thus, from a timber production 

standpoint, the maintenance of mixed pinehardwood stands is likely to be more costly than 

maintenance of pure stands, especially in the uneven-aged situation where it may be prohibitively 

costly. 

CONCLUSION 

There are conditions in uneven-aged stands where 

a hardwood component in addition to the pine component can increase the total growth of the stand. 

These conditions are usually where pine basal area 

is less than about 60 square feet per acre. Above 

this level the addition of hardwoods decreases the 

total growth. Although the density is within the 

range suitable for selection management, the 

added growth due to the hardwoods usually does 

not appreciably increase the total stumpage value. 

A hardwood component usually decreases total 

stumpage because its growth and value are generally much less than that for pine. For these and other 

reasons, it is suggested that a hardwood component is best accomodated as separate pure aggregations or stands rather than dispersed 

throughout the pine stand. 

The stand-level models developed here provide 

some useful insight into the function of mixed 

stands. However, they are limited in their ability to 

explain mixed stand growth and constitute little 

more than a primer. They do not take into account 

the impact of a number of additional possible factors such as differential rates of growlh, ingrowth, 

and mortality among species; the distribution of 

species and stems vertically in the understory, 

midstory, and overstory; distribution of species and 

stems laterally over area; and Inter-tree influences. 

Evaluation of these effects is largely beyond the 

capability of stand-level growth prediction systems 

and individual-tree systems will be required to quantify these effects. 

ACKNOWLEDGEMENTS 

We are indebted to Dr. Bill Pope and Mr. Jerry Coffman of Potlatch Corporation in Warren, Arkansas, 

for making their inventory data available. We also 

wish to thank Dr. Michael Shelton, Southern Forest 

Experiment Station, for his helpful suggestions and 

critical review. 
LITERATURE CITED 

Bormann, F.H. 1956. Ecological implications of 

changes in the photosynthetic response of Pinus 

seedlings during ontogeny. Ecology 37:70- 

75. 

Bower, David R.; Ferguson, Edwin R. 1968. Understory removal improves shortleaf pine growth. 

Journal of Forestry 66:421-422. 

Boyer, William D. 1986. Role of competing 

vegetaion in forest health. pp. 235-239. In: 1986 

National Convention, Society of American 

Foresters, 1986 October 5-8, Birmingham, AL. 

Boyer, William D. 1987. Volume growth loss: a hidden cost of periodic prescribed burning in 

longleaf pine? Southern Journal of Applied 

Forestry 1 1 : 154-1 57. 

Burkhart, Harold E.; Sprinz, Peter T. 1984. A model 

for assessing hardwood competition effects on 

yields of loblolly pine plantations. Publ. No. FWS3-84. Blacksburg, VA: Sc hoot of Forestry and 

Wildlife Resources, Virginia Polytechnic Institute 

and State University. 31 p. 

Cain, Michael D. 1985. Long-term impact of 

hardwood control treatments in mature pine 

stands. Res. Paper SO-21 4. New Orleans, LA: 

U.S. Department of Agriculture, Forest Service, 

Southern Forest Experiment Station. 8 pp. 

Cain, M.D.; Yaussy, D.A. 1984. Can hardwoods be 

eradicated from pine sites? Southern Journal of 

Applied Forestry 8:7-13. 

Clason, T.R. 1978. Removal of hardwood vegetation 

increases growth and yield of a young loblolly 

pine stand. Southern Journal of Applied Forestry 

2196-97. 

Grano, C.X. 1970. Small hardwoods reduce growth 

of pine overstory. Res. Paper SO-55. New Orleans, LA: U.S. Department of Agriculture, Forest 

Service, Southern Forest Experiment Station. 9 p. 

Hebb, E.A. 1981. Choctawhatchee sand pine 

growth on a chemically prepared site: 10-year 

results. Southern Journal of Applied Forestry 

5:208-211. 

Michael, J. L. 1980. Long-term impact of aerial application of 2,4,5-T to longleaf pine (Pinus 

mlustris). Weed Science 28:255-257. 

Paul, Benson H. 1933. Mixed stands produce pine 

lumber of higher grade. The Southern Lumber 

Journal 37(4): 26. 

Pienaar, L.V.; R heney, J. W. ; Shiver, B. D. 1983. 

Response to control of competing vegetation on 

site prepared slash pine plantations. Southern 

Journal of Applied Forestry 7:38-45. 

Rogers, Nelson F.; Brinkman, Kenneth A. 1965. 

Shortleaf pine in Missouri: understory hardwoods 

retard growth. Res. Paper CS-15. Columbus, OH: 

U.S. Department of Agriculture, Forest Service, 

Central States Forest Experiment Station. 9 p. 

Russel, T.E. 1961. Control of understory hardwoods 

fails to speed growth of pole-size loblolly. 

Southern Forestry Notes 131 :3-4. New Orleans, 

LA: U.S. Department of Agriculture, FQ~C~S~ Service, Southern Forest Experiment Station. 

Russel, T. E. 19633. Planted shortleaf responds to 

prompt release. Tree Planters' Notes No. 61 : 13- 

16. U.S. Department of Agriculture, Forest 

Service. 

SAS Institute, Inc. 1984. SAS/ETS user's guide, version 5 edition. Cary, NC: SAS Institute. 738 p. 

Wahlenberg, W.G. 1948. Effect of forest shade and 

openings on loblolly pine seedlings. Journal of 

Forestry 46:832-834. 

Wahlenberg, W.G. 1960. Loblolly pine. Durham, 

NC: School of Forestry, Duke University. 603 p. 
INDIVIDUAL TREE GROWTH RELATIONSHIPS IN 

PINE-HARDWOOD MIXTURES 

Paul A. Murphy, Robert M. Farrar, Jr. and R. Larry ~illett' 

Abstract. -A study was established in southeast Arkansas in 1983 in which 5-year growth data 

were used to examine the relationship between pine and hardwood tree basal area growth and 

various tree and stand variables. Separate analyses were made for each species. A comparison 

was also made between distance-independent measures and a distance-dependent measure 

(area potentially available, APA) of competition. The APA did not make any additional statistical 

contribution to regressions of tree basal area growth in the presence of other stand variables, An 

analysis was made of a set of inventory data from south Arkansas for comparison. Regressions 

using these data indicate that basal area component variables (by rank and species) have good 

predictive power. The results should be useful to modelers investigating growth relationships and 

to researchers who are contemplating installation of similar studies, 

INTRODUCTION 

The growth of an individual tree is affected by its 

neighbors. How this competition is described 

depends upon whether the spatial arrangement of 

the trees is taken into consideration. If these data 

are not considered, then competition must be 

described by models employing some aggregate 

stand variables--such as number of trees, basal 

area, or quadratic mean diameter. These models 

have been traditionally called d istance-independent 

models. If the spatial arrangement of the trees is 

considered, then a host of intertree competition 

measures have been proposed - crown overlap, 

Hegyi's index, and area potentially available (APA) 

to name just a few. Models employing these 

measures have been termed distance-dependent, 

and this modeling activity has been applied almost 

exclusively to even-aged, single-species stands. 

The effect of competition by other trees on growth 

of the subject tree is more complex in uneven-aged 

and mixed-species stands. It is questionable 

whether some of the techniques developed for 

simpler conditions can be applied to these stands. 

If the subject tree is a loblolly pine, will the competitive effect of a pine neighbor be the same as that of 

a hardwood of similar height and diameter? The 

problem is especially acute in uneven-aged pinehardwood mixtures. 

In this paper we discuss an effort to describe intertree competition and its effect on individual tree 

growth in uneven-aged loblolly-shortleaf pineupland hardwood stands. Both distance-independent and distance-dependent models are used. 

hesearch Foresters, Southern Forest Experiment Station, Monticello, AR, in cooperation with the Department 

of Forest Resources and the Arkansas Agricultural Experiment Station, University of Arkansas at Monticello; and 

Extension Forester, University of Arkansas Cooperative 

Extension Service. Monticello. 

The data are from a study installed on the Crossett 

Experimental Forest and a permanent plot inventory system maintained by Potlatch Corporation on 

their lands in south Arkansas. 

STUDY AND DATA DESCRIPTION 

Pine-Harhood St@ 

A study was installed on the Crossett Experimental 

Forest in south Arkansas in 1983 to investigate 

volume growth and wildlife habitat suitability of erneven-aged pine-hardwood stands composed of different percentages of loblolly-shortleaf pine and 

hardwoods. The study area is located on a terrace 

adjacent to a small stream, and the soil is 

predominantly a Bude silt loam with some 

Providence silt loam. The site index is about 90 feet 

for loblolly pine at 50 years (U.S. Department of 

Agriculture, Forest Service 1 976). 

Fifteen 0.62-acre square plots, each with an interior 

square measurement plot area of 0.22 acre, were established in a pine-hardwood stand. Five treatments were applied that would leave a residual 

basal area of 65 square feet per acre in stems 3.6 inches in dbh and larger in the following pinehardwood proportions: (1) 100 percent pine, (2) 90 

percent pine and 10 percent hardwood, (3) 80 percent pine and 20 percent hardwood, (4) 70 percent 

pine and 30 percent hardwood, and (5) 50 percent 

pine and 50 percent hardwood. Preference was 

given to oaks in selecting the hardwoods because 

they are hard mast producers; the red oaks were 

favored over the white oaks in a 2 to 1 ratio insofar 

as possible because of their more reliable mast 

production. Three replications of the five treatments were installed in a completely randomized 

design--subject to the constraint of being able to impose a given treatment on a plot. The plots were 

cut to attain these treatments during the 1983-84 

dormant season. 
AII remaining trees on the plots were assigned a 

tree number. Tree measurements were taken and 

consisted of species' identification and measuring 

d bh to the nearest 0.1 -inch at the uphill ground 

level during the f 983-84 dormant season after cut- 

"ing In January 1987, all live trees were mapped 

by measuring the azimuth to the nearest degree 

and distance from plot center to tree center to the 

nearest 0.1 fost. The azimuth and distance of trees 

that had died after the study was begun were also 

determined. During October 1988, dbh's of all trees 

were remeasured. Only species having at least 14 

surviving trees were included in the analysis (table 

Wangenh.). Details about the measurement of 

mast, herbaceous, and browse production are 

described by Wigley and others (1 989). 

Table 1,--Summary statistics for fifteen 0.22-acre plots of a 

pine-hardwood study on the Crossett Experimental Forest, 

1983-1988. 

1983 Diameter 

Species Nurnber of Average annual 

trees dbh growth Mean S.D. 

Shortleaf pine 14 0.12 15.1 5.9 

Loblolly pine 86 0.22 17.4 6.2 

bhrte oak 3 3 0.21 10.0 4.5 

Southemredo& 18 0.19 9.0 2.5 

Water a& 24 0.27 11.2 3.6 

pose oak 1 6 0.23 9.2 2.4 

'The inventory data are from 0.2-acre circular plots 

tscated in uneven-aged loblolly-shortleaf pine 

stands on Potlatch Corporation lands. These plots 

also had a varying hardwood component. Measuremends were conducted in 1966, 1971, and 1976. Information was maintained for each individual tree 

5.0 inches and larger in dbh. Pertinent information 

used far this analysis were: (1) dbh to the nearest 

O 1 inch, (2) species, and (3) tree history. No data 

were used from plots that had been logged or that 

had received any other disturbance during a 

measurement period. Each plot had the potential 

of yielding two gro\NTh observations per tree. Only 

species having at feast 200 growth ohsenrations 

were ineluded in the analysis (table 2); these were 

loblcslly pine, shortteaf pine, southern red oak, water 

oak, and sweetgum ( 

L.). 

Table 2.--Summary statistics for inventory data from Potlatch 

Corporation stands in south Arkansas, 1966-1376. 

Initial 

drameter 

Species Nmber of Average mual 

trees dbh growth Mean S.D. 

Shortleaf pine 1027 0.23 9.9 3.0 

~oblolly pine 5860 0.29 10.1 3-13 

Southern red oak 336 0.26 10.6 3.7 

Water oak 204 0.27 10.7 4.2 

Post oak 256 0.14 9.2 3.1 

Sweetp 473 0.14 9-6 3.3 

ANALYSIS 

The objectives of this analysis were (1) to identify 

two variables that could be used for modeling individual tree basal area grovvth in a distance-independent context, (2) to investigate the use and 

modification of the APA index for describing individual tree basal area growth and how it might be 

modified, and (3) to measure the contribution of 

APA to explaining tree growth when used in conjunction with other variables. 

We assumed that the growth response of a tree 

varies a~~~rding to the size and species compos!- 

tion of its competitors. Therefore, all stand variables were summarized separately for the two 

taxonomic classes. Furthermore, we assumed that 

a tree will react according to its stand hierarchy and 

the species composition (pine or hardwood) of the 

hierarchy. This hierarchy can be based on any 

number of variables; we chose basal area and 

diameter. To express this hierarchy, we parlitisned 

basal area and diameter according to the amount 

above and below the tree in rank. Thus these variables are unique for each tree; the basal area or 

diameter of a tree is not included when it is the subject tree. Using these assumptions, we came up 

with a total of 17 variabies for testing. In addition to 

the initial subject tree diameter, each of the Following variables was tested for both pine and 

hardwood components: 

(1 )Quadratic mean diameter 

(2)Number of trees 

(3) Basal area 

(4)Sum of diameters 

(5)Sum of diameters of trees larger than subject tree 

(6)Sum of diameters of trees smaller than subject 

tree 

(7)Sum of basal areas of trees larger than subject 

tree 

(8)Sum of basal areas of trees smaller than subject 

tree. 
All the variables were calculated using the 1 983 

measurement and expanded to a per-acre basis 

where appropriate. We first conducted regression 

analyses by pine and hardwood to determine which 

two variables were best for modeling (using R~ as 

the criterion). Using these results, a separate 

analysis was then done for each species. 

The use of APA was also investigated. The APA 

method was first proposed by Brown (1 965). In the 

original application, a convex polygon was constructed around the subject tree by drawing a set of 

lines that are perpendicular bisectors of other I ines 

drawn from the subject tree to its neighbors. 

However, this only considered intertree distance 

and not tree size in constructing the polygons. 

Thus correlations between growth and APA were 

not high. Moore and others (1 973) modified the 

construction so that the perpendicular bisector was 

located at a point that was determined by the sizes 

of the subject and competitor tree: 

where: 

lij = distance from subject tree i to the weighted 

point between tree i and its competitor j, 

Lij = distance between the subject and competitor 

tree, and 

O = tree diameter. 

In this case, the weight is D~. Other weighting factors can be used as well. Daniels and others (1986) 

compared several competition measures and found 

that only APA and another distance-dependent competition index contributed to growth predictions in 

conjunction with using distance-independent variables. There was still a problem with the technique, 

however, when gaps occurred in the stand. Thus, 

more APA might be allocated to a tree adjacent to 

the gap than what it could effectively utilize. Nance 

and others (1 988) solved this problem by constraining the distance lij to being no more than some percentage of the crown radius of an open-grown tree 

of equivalent diameter. If: 

where: 

Imax,i = constrained distance for tree i, 

Char = mean crown ratio of all trees in stand, 

Cmax = maximum attainable mean crown ratio for 

stands of same species, 

bo, bt = species dependent coefficients, and 

(bo + blDi) = crown radius of an open-grown tree 

of same species and diameter. 

Then: 

li,j* = minimum {Ii,j,Imax,i} 

where: 

li,j* = distance between subject tree i and competitor tree j. 

APA was formulated for single species, even-aged 

stands, and it may not be suited to multiplespecies, uneven-aged conditions in which crowns 

occupy different levels in the canopy layer and 

where there can be crown overlap such that a small 

tree may occur beneath a large one. However, 

Moore and others (1 973) used uneven-aged mixed 

hardwood data in their development of weighted 

APA. A possible adaptation of APA for different 

species might be to weight the tree diameters according to species in the following manner, 

where: 

wi = weight for the subject tree, 

W, = weight for the competitor tree, and 

Zij = the distance between the subject tree and the 

weighted point between the subject and 

competitor trees, and 

Ideally, equation (4) would be constrained using a 

separate crown radius equation for each species. 

However, few species-specific crown radius (or 

diameter) equations for open-grown trees exist for 

the species represented here. A graphical comparison (crown radius or diameter vs. dbh) of equations for upland oaks (Minckler and Gingrich 1970), 

shortleaf pine (Rogers 1983), and the equation for 

loblolly pine used by Nance and others (1988) 

showed little difference between the oaks and loblolly pine, while the crown radius of shortleaf pine 

graphed slightly below the oaks and loblolly pine. 

Therefore, the loblolly pine equation was used for all 

species. Equation (2) was changed to read, 

where: 

Zmax,i = constrained distance for tree i, 

r = crown radius constraint (r > O), and 

(2.0 + 0.8Di) = crown radius (ft) of open-grown 

tree (loblolly pine). 

The actual distance between the subject and the 

competitor tree is now: 

Zi,j* = minimum {Zij,Zma,,i) 
The APA's were calculated using software developed developed by Nance and others (1 988). They 

were correlated with tree basal area growth by letting the weight for pine equal 1 as the weight for 

hardwood (w) varied from 0.1 to 4.0 in increments 

of 0.1. The crown constraint was also tested by letting r in equation (5) vary from 0.05 to 1.0 in increments of 0.05. 

The final step in the analysis was to test whether or 

not the addition of APA to distance-independent 

variables already in a regression significantly explains tree basal area growth. This was done for 

each species. 

In this analysis, we were interested in specifying a 

single model for the different species and observing 

model performance and consistency of the coefficients for each species. We were interested in 

specifying an equation in which the competitive 

position of the tree is portrayed. This competitive 

position must also take into account species 

groups. The equation we selected was, 

BAG = a0 + al(DBH) + a2(PBAf3) 

+ aa(PBAA) + a4(HBAB) + as(HBAA), 

where: 

BAG = tree basal area growth (sq ft), 

DBH = initial tree diameter (inj 

PBAB = basal area (sq ftlac) in pine trees smaller 

than the subject tree, 

PBAA = basal area (sq ftlac) in pine trees larger 

than the subject tree, 

HBAB = basal area (sq ftlac) in hardwood trees 

smaller than the subject tree, 

HBAA = basal area (sq fttac) in hardwood trees 

larger than the subject tree, and 

aj = coefficients to be estimated 

It should be noted that the sum of the basal areas 

plus the basal area of the subject tree equals the 

total basal area. 

RESULTS 

The best variables (based upon R2) for loblolly and 

shortleaf pine were individual tree diameter and the 

quadratic mean diameter of pine; individual tree 

diameter and the pine basal area above the subject 

tree were the best variables for hardwoods. The FI2 

for loblolly pine was not high (table 3)' and the low 

value may reflect the older ages and larger sizes of 

the loblolly trees; their growth has culminated and 

they may be in a senescent stage of their development. The fit for shortleaf pine is much better; the 

shortieaf trees may be either younger or capable of 

longer sustained growth. 

Table 3.--Statistical evaluation of tree basal area growth models 

for a pine-hardwood study on the Crossett Experimental Forest. 

Species Two-variable APA Two-var~able re resslon 

regressionsa alone plus AFA f? 

F-value -- -- - - ,--R2-.. - ---- ---- [probability level) 

Loblolly pine 0.45 0.39 0.95 (0.331 

Shortleaf pine 0.72 0.62 1.14 (0.311 

White oak 0.42 0.34 0.04 (0.84; 

Southern red oak 0.49 0.48 0.28 (0.61) 

Water oak 0.63 0.33 0.08 (0.78) 

Post oak 0.43 0.50 2.56 (0.14) 

?'he independent variables for loblolly and shortleaf pines 

were initial diameter end quadratic mean diameter of pines; the 

independent variables for hardwoods were initial diameter of 

subject tree and basal area in pine trees larger than the subject 

tree. 

b~he APA (area potentially available) values were calculated 

with a crown radius constraint of 0.4 and equal weights for pine 

and hardwood. 

'The F-values are type I11 sums of squares (SAS Institute 1986) or the sums of squares attributEible to APA, given that the other 

independent variables are already in the model. 

The apparent usefulness of the pine basal area 

above the subject tree for describing hardwood 

basal area growth was a surprise. However, on 

these plots the hardwoods were smaller than the 

pines and had subordinate canopy positions. 

Therefore, this variable probably reflects the competitive position of the hardwoods. If the 

hardwoods had occupied both superordinate and 

subordinate canopy positions, the variable selection 

might have been different. Except for water oak, 

the R 'S for the hardwoods were similar to the one 

for loblolly pine (table 3). 

Figures 1-4 show the effect of the hardwood weights 

(w) and selected crown radius constraints (r). Each 

graph depicts the root mean square errors 

(RMSE's) resulting from using APA in a simple 

linear regression model with tree basal area growth 

as the dependent variable. Weighting the 

hardwood diameters did not seem to affect RMSE's 

that much, and the strategy of giving equal weighting to all species appears to be as good as a more 

complicated weighting scheme. 

To isolate the effect of the crown radius constraint, 

we gave equal weighting to both pine and 

hardwood and allowed the crown constraint to vary 

from 0.05 to 1 .OO in increments of 0.05. The results 

(figure 5) are not consistent over species. Some 

have definite minimum RMSE's (e.g., post oak), 

while other RMSE's consistently increase as the 

crown radius constraint is relaxed. 

Figures 6 to 8 show maps of tree polygons on a representative plot for different crown radius con- 
- 

SHORTLEAF ---- MITE OAK 

---- WATER OAK 

--.--- 

--- LOBLOiLY 

WHEW RED OAK --- POST MK 

- 

SGRTLEAF ----*- 

---- --- LOBLOLLY 

---- WiTE OAK - -- SOVTHERN RED QAK 

WATER OAK POST OAK 

Figure 1 .--Effect of hardwood diameter weighting 

and a crown radius constraint of 0.1 on root mean 

square error (RMSE) of the regression of tree basal 

area growth as a function of APA, by species. 

Figure 2. --Effect of hardwood diameter weighting 

and a crown radius constraint of 0.4 on root mean 

square error (RMSE) of the regression of tree basal 

area growth as a function of APA, by species. 

0 1 2 3 4 

HARDWOOD WE IGHT 

0 I 2 3 4 

HARDWOOD WEIGHT 

- 

---- SWRTLEAF 

WITE OAK 

WATER OAK 

------ LOBLOLLY 

WTHERN RED OAK --- WST OAK 

- 

SMRTLEAF ---- WHITE OAK ---- WATER OAK 

------ LOBLOLLY -- - SOUTHERN RE0 OAK 

POSY OAK 

Figure 3.--Effect of hardwood diameter weighting 

and a crown radius constraint of 0.7 on root mean 

square error (RMSE) of the regression of tree basal 

area growth as a function of APA, by species. 

Figure 4.--Effect of hardwood diameter weighting 

and a crown radius constraint of 1.0 on root mean 

square error (RMSE) of the regression of tree basal 

area growth as a function of APA, by species. 

straints. The crown radius constraint affects larger, 

isotated trees most dramatically. Even when the 

constraint is 1.0, the polygons do not completely occupy the growing space, which is a reflection of the 

residual density of only 65 square feet per acre. 

The R~'S for the growth model using the basal area 

components range from 0.29 for sweetgum to 0.61 

for post oak: 

To test the effect of using APA in conjunction with 

other variables, the APA's were calculated with 

w=1.0 and rzQ.4. The constraint of r -0.4 represents a compromise choice based on the conflicting behavior of the RMSEJs in figure 5. Table 3 

shows the effect of adding APA to the two-variable 

regression. The APA did not make a significant con 

tribution to the model for any species. Perhaps a 

straightfoward application of APA to mixedspecies, uneven-aged conditions does not work, 

and some refinement is necessary. 

Lobiolly pine 0.55 

Shortleaf pine 0.50 

Southern red oak 0.54 

Water oak 0.50 

Post oak 0.61 

Sweetgum 0.29 

In all cases, the sign of the coefficient for initial dbh 

was positive, and the sign of the coefficients for the 

basal area variables were negative. 1 hus the results 
0. 0, .* 0, a, 9. 0. 01 a* 0. 1. 

CROWN RADIUS CDNSTRA INT 

SIU1TL-F ------ LOBCOLLY ---- 

- - - - WIT€ MY 

5CVTkER*r RED a4K -- VATER OAK RXT OIK 

Figure 5.--Effect of crown radius constraint on root 

mean square error (RMSE) of the regression of tree 

basal area growth versus APA with equal weighting 

of pine and hardwood, by species. 

SHORTLEAF 1-1 LOBCOLLY 

Figure 7.--Map of tree polygons for plot 31 of the 

pine-hardwood study located on the Crossett Experimental Forest with crown radius constraint of 

0.7. 

are consistent. High probabilities (p > 0.10) occurred four times (table 4). Three of these were for 

basal area components below the subject tree. The 

results indicate what degrees of fit might be expected for inventory data and are a baseline for 

results from controlled studies. 

CONCLUSION 

The results from this study are indicative, not conclusive. The APA and other distance-dependent 

com petit ion indexes probably need modification if 

they are to be used for mixed-species or unevenaged conditions. These indexes were developed for 

single-species even-aged stands with a single 

canopy layer and need refinement before they are 

applied to multiple canopied situations where 

crown overlap is a common occurrence. 

Figure 6.--Map of tree poiygons for plot 31 of the 

pine-hardwood study located on the Crossett Experimental Forest with crown radius constraint of 

0.4. 

Figure 8.--Map of tree polygons for plot 31 of the 

pine-hardwood study located on the Crossett Experimental Forest with crown radius constraint of 

1 .o. 

In the present study the hardwoods generally occupied subordinate canopy positions. If some 

hardwoods can compete successfully with pines 

and occupy the same canopy layer, then study 

plots should have hardwoods in both superordinate 

and subordinate positions relative to the pines. 

While cognizant of the fact that different models 

were used, the goodness-of-fit statistics for the controlled study were somewhat disappointing compared to those from the inventory data. It indicates 

that perhaps the study design could be improved. 

The poor fit for loblolly pine was probably the result 

of advanced tree ages. Locating plots in vigorously 

growing stands with relatively young trees might assure a better growth response as well as lengthening study life if even-aged conditions are being 
Table 4.--Statistical evaluation of tree basal area growth model 

for inventory data from Potlatch Corporation stands in south 

Arkmsas . 

variablea 

Species DBH HBAA HBA3 PBAB PBAA 

--------- 

Loblolly pine 2233.25 

(0.0) 

Shortleaf pine 355.42 

(0.0) 

Southernred 172.61 

oak ((0.01) 

Water oak 25 53 

((0.01) 

Post oak 177.95 

(<0.01) 

Sweetgwn 102.54 

(co.01) 

- - 

-F-value (probability level lb-------- 

80.59 0.0 220.27 1018.84 

(CO.01) (0.96) (CO.01) (0.0) 

4.58 7.86 30.14 172.18 

(0.03) (0.01) (<o.oli (<o.or) 

19.37 6.84 9.99 2.41 

((0.01) ((0.01) ((0.01) (0.12) 

31.62 10.92 1.44 23.70 

((0.01) ((0.01) (0.23) ((0.01) 

13.72 1.11 17.09 5.04 

(<o,ol) (0.29) (~0.01) (0.03) 

22.02 24.52 29.05 3.82 

((0.01) ((0.01) ((0.01) (0.05) 

%BH is the initial diameter, HBAA is the basal area in 

hardwood trees larger than the subject tree, HBA3 is the basal 

area in hardwood trees smaller than the subject tree, PBAB is 

the basal area in pine trees larger than the subject tree, and 

PBAA is the basal area in pine trees smaller then the subject tree. 

bThe F-values are type I11 sums of squares (SAS Institute 1986) 

or the sums of squares attributable to APA, given that the other 

independent variables are already in the model. 

studied. The species range of the hardwoods 

should also be restricted and confined to those with 

similar growth rates, so that differences in 

hardwood species can be minimized. 

Competition studies have a rich history in plant 

population ecology, and the study design irnplernented here is termed a "replacement series experiment" in which the total density is constant but 

where the species proportion is varied (Silverton 

1987). A second study design is an "additive experiment" in which the density of one species is fixed 

while the density of the other is varied. A third is 

called an "additive series experiment," and it is essentially a combination of the other two and is the 

most comprehensive. We hearlily re~~rnmend this 

last design to anyone contemplating a pinehardwood density experiment. 70 illustrate how it 

can be impiemented in an uneven-aged pinehardwood stand, we might consider "Ie following 

density levels: 

Pine b sal area 2 Hardwoo basal area 

(Ft /acre> (Ft 9 /acre) 

-- 

----a. 

2 (Total f t /acre) ----- 

50 50 60 70 

60 60 70 80 

70 70 80 90 

For a given level of pine, one can assess the impact 

of different levels of hardwood and vice versa. Also 

there are contrasts that can be made on diagonal 

eiernents of the table where the total basal area is 

constant but the prepoflions vary. The additive 

series design allows a more csmprehensive 

analysis than the replacement series and simple additive designs. 

Our knowledge of the gaovvth and development of 

pine-hardwood midures is very rudimentary. But it 

is encouraging to note that well designed studies 

should contribute greatly to our future understanding. 

ACKMG$WLEBGM%MT% 

We wish ta thank Dr. Bill Pope and Mr. Jerry 

Coff man sf Potlatch Corporation, Warren, AR, for 

lending their inventory data. 
LITERATURE CITED 

Brown, G.S. 1965. Point density in stems per acre 

New Zealand Forest Res. Notes No. 38. 7 p. 

Daniels, Richard F.; Burkhart, H.E.; Clason, Terry 

R. 1986. A comparison of competition measures 

for predicting growth of loblolfy pine trees. 

Canadian Journal of Forestry Research 16: 1230- 

1237. 

Minckler, Leon S.; Gingrich, Samuel F, 1970. Relation of crown width to tree diameter in some 

upland hardwood stands of southern Illinois. Res. 

Note NC-99. St. Paul, MN: U.S. Department of 

Agriculture, Forest Service, North Central Forest 

Experiment Station. 4 pp. 

Moore, J.A.; Budelsky, C.A.; Schlesinger, R.C. 

1973. A new index representing individual tree 

competitive status. Canadian Journal of Forestry 

Research 3:495-500. 

Nance, Warren L.; Grissom, James E.; Smith, W.R. 

1988. A new competition index based on 

weighted and constrained area potentially available. pp. 134-142. In: Ek, Alan R.; Shifley, 

Stephen R.; Burk, Thomas E., eds. Proceedings, 

IUFRO conference on forest growth modelling 

and prediction; 1983 August 23-27; Minneapolis, 

MN. Gen. Tech. Rep. NC-120. St. Paul, MN: U.S. 

Department of Agriculture, Forest Service, North 

Central Forest Experiment Station; Vo9. 1 : 1-579. 

Rogers, Robert. 1983. Guides for thinning shortleaf 

pine. pp. 217-225. In: Jones, Earle P., Sr., ed. 

Proceedings of the second biennial southern silviculture research conference; 1982 November 

4-5; Atlanta GA. Gen. Tech. Rep. SE-24. Asheville, 

NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station. 

SAS institute, Inc. 1986. SAS system for linear 

models, 1986 edit ion. Cary, NC: SAS Institute. 

210 p. 

Silverton, Jonathan W. 1987. Introduction to plant 

population ecology. 2nd ed. Essex, England: 

Longman Scientific and Technical. 229 p. 

Wigley, 1. Bentley; Willett, R. Larry; Garner, Michaei 

E.; Baker, James 0. 1989. Wildlife habitat quality 

in varying mixtures of pine and hardwood. [These 

Proceedings.]. 

U.S. Department of Agriculture, Forest Service. 

1976. Volume, yield, and stand tables for secondgrowth southern pines. Misc. Publ. 50 [revision of 

1929 edition]. Washington, DC: U.S. Department 

of Agriculture. 202 pp. 
RELATIVE BASAL AREA AS IT APPLIES TO 

PINE-HARDWOOD MlXrURES IN THE UPPER COASTAL 

PWIN 

Michael D. Cain' 

.-In the late 1930's, three studies were established in natural pine-hardwood stands in 

southern Arkansas to investigate the long-term growth of merchantable-s~ze stems. With no 

management or low-intensity management, relative density of merchantable-size pines tended to 

be negatively related to relative density of merchantable-size hardwoods, whereas relative basal 

area of pines and hardwoods remained nearly constant through time. With more intensive 

management, as in using periodic improvement cuts and hardwood control, pines benefited by 

increasing in relative density and relative basal area compared to hmdwoods. It appears that 

there is a rather narrow range in relative basal area for merchantable-size pines and hardwoods 

that may perpetuate the productivity of pine-hardwood mixtures. 

INTRODUCTION 

A vast resource of pines has been perpetuated in 

the South over the last 50 years as a result of 

biological, economic, and social forces (Boyce and 

Knight 1 980). Compared to most hardwood 

species on Upper Coastal Plain sites, pines tend to 

have faster growth, are in greater demand by forest 

industry, and usually bring a better price to landowners. In order to increase pine production, 

forest managers have discouraged hardwood 

management. This has been necessary because 

hardwoods on upland pine sites not only compete 

with pines, but also are often slow growers, scarred 

with short and crooked boles, and highly variable in 

species' composition. If forest managers decide to 

harvest these hardwoods, they usually obtain low 

volumes per acre that tend to increase harvesting 

costs (Karchesy and Koch 1979). 

Even though the management emphasis has been 

on pine productivity, many private nonindustrial 

forest landowners (PNIFL's) do not perceive timber 

production as their principal ownership goal (Porterfield 1984). These landowners, who control more 

than 70 percent of the forest land in the South, have 

a variety of reasons for woodland ownership. In addition to timber production, these reasons may include aesthetics, recreation, wildlife, private retreat, 

and firewood. Because of such varied interests, 

many PNIFL's would be better served by pinehardwood mixtures rather than by pure pine or 

pure hardwood forests. 

tigations in natural stands under various levels ~f 

management are presented in this paper. These 

data suggest that relative basal area of the pine and 

hardwood components may provide a potential 

management strategy for sustaining pine timber 

productivity from mixed pine-hardwood stands. 

METHODS 

Studv Area 

Study plots were located on the Crossett Ex erimen- I? tal Forest in Ashley County, Arkansas, at 33 02'N 

mean latitude and 91 O56'~ mean longitude. Annual precipitation averages 55 inches, with extremes being wet winters and dry autumns. 

Elevation of the area is about 175 feet, with nearly 

level topography. Soils are Bude (Glossaquic 

Fragiudalfs), Providence (Typic Fragiudalfs), and 

Arkabutla (Aeric Fluvaquents) silt loams (USDA 

1979). Bude and Providence soils were formed in 

thin loessial deposits and have an impervious layer 

at 18 to 40 inches that impedes internal drainage. 

The Arkabutla soil was formed in silty alluvium and 

is subject to flooding in late winter and early spring. 

These soils have an excellent potential for the 

growth of commercially important hardwoods and 

pines. Site indices (S.I.) at 50 years are as follows: 

cherrybark oak (Quercus falcata var. pagodifolia 

Ell.), S.I. = 90 to 105 ft; sweetgum (Liquidambar 

styraciflua L.), S.I. = 85 to 100 ft; shortleaf pine 

(Pinus echinata Mill.), S.I. =80 to 90 ft; and loblolly 

pine (P. taeda L.), S. I. = 85 to 100 ft. Old-growth 

pine timber on the forest was cut before 191 5 to a 

12-inch d. b. h. limit. There were recurrent wildfires 

until fire protection began in the 1930's. 

Knowledge of successional patterns relative to 

various levels of stand disturbance is important for 

the successful management of a mixed pinehardwood forest. Data from three long-term invesStudv Historv 

'~esearch Forester, Southern Forest Experiment Station, USDA Forest Service, Monticello, AR 71655, in 

cooperation with the Department of Forestry and the 

Arkansas Agricultural Experiment Station, University of 

Arkansas at Monticello. 

Three long-term investigations had been initiated on 

the Experimental Forest during the late 1930's and 

early 1 940's. These investigations included an unmanaged stand, a pine release study, and a 
methods-of-cut study. Periodic inventories were 

made of the number of merchantable-size trees 

(stems 3 8 inches in d.b.h. and larger) to provide a 

record of pine and hardwood productivily through 

time. BiFferent silvicultural practices were utilized in 

the management sf these rhree studies as fo9lows: 

Unmanaged stand. dn 1935, an 80-acre stand was 

set aside to be kept from future management. With 

the exception of fire protection and occasional cutand-leave or salvage of small bark beetle iafestations, no management practices have been undertaken in this stand. In 1937, density of pines and 

hardwoods 4 inches in d.b h and larger averaged 

130 and 47 trees per acre respectively. 

Pine release study, Phis investigation was initiated 

to determine if suppressed pine seedlings would 

respond to release fram a pine-hardwood overswry. 

In 1939, there was an average of 75 merchantablesize pines and 54 merchantable-size hardwoods 

per acre in this 16-acre study area. About 1,400 

pines per acre were of submeschmtable size, and 

about 6,000 hardwood trees and shrubs per acre 

were less than 4 inches in d.b.h. Three intensities 

sf pine release were tested: remove overstory 

hardwoods; remove midstory and sverstory 

hardwoods; and remove midstory, overstory, and 

some understory hardwoods. Each treatment was 

replicated four times and hardwoo& were removed 

by tuning. f n 1955, there was pagial repetition of 

each treatment using the herbicide 2,4,5-P. Hawesting of merchantable pines and hardwoods was 

done using the single tree selection system in 1939, 

1949, 1955, 1960, and 1965 (when management 

ceased). The only silvicultural treatment applied 

since 1965 was a prescribed burn over the entire 

area in 1980 for fuel hazard reduction. 

Methods-sf-cut study.This study was initiated to 

determine the enectiveness of four different 

reproduction cuning methods--selection, diameterlimit, heavy seed-tree, and patc k clearcuEing--for 

obtaining adequate pine regeneration, for enhancing pine growth and yield, and for dealing with lowquality hardwoods. The study was installed as two 

series. The first series was established in 4937 and 

the second series in 3 942. AIB four treatments were 

replicated three times in each series on 4.4-acre 

plots The initial density of the merchantable component averaged 136 stems per acre FOP pines and 

73 sfems per acre for hardwoods. 

In the seieetion met hod, merchantable pines were 

harvested as single trees or small groups on a 5- 

year cutting cycle. Merchantable hardwoods were 

harvested when the study began and all remaining 

hardwoods larger than 4 inches in d.b.h, were cut 

about 3 years later. Harvesting sf pines and 

hardwoods ceased atter 1968. 

In the diameter-limit method, all pine sawtimber 

larger than 1 1.5 inches in d. b. h and all merchantable hardwoods were harvested when the study 

began. All remaining hardwoods larger than 4 inches in d.b.h. were cut about 3 years after the initial 

harvest to release pine regeneration. Subsequent 

pine diameter-limit cuts were conducted at 5- to 10- 

year intervals until W68 when hawesting ended. 

In the heavy seed-tree method, all merchantable 

pines and karb\n/oods were harvested when the 

study began except that 45 to 20 pine seed trees 

were left per acre. Pine regeneration was released 

about 3 years aCrer the initial harvest by cutting 

remaining hardwo'ods larger than 4 inches in d.b.h. 

Seed trees were removed about 15 years after the 

initial cut and there was no further activity. 

In the patch ciearcut method, all merchantable 

pines and hardwoods larger than 5.5 inches in 

d.b.h. were har~ested when the study began. 

Prescribed burning was used shortly after to reduce 

logging slash, to prepare a seed bed for natural 

pine regeneration, and to control small hardwoods. 

Residual hardwoods larger than 4 inches in d. b. h. 

were cut about 3 years after the initial harvest. 

Unmanaged stand. Periodic inventories of ail trees 

4 inches in d.b.h. and larger were conducted between 1937 and 1983 at 5- to 10-year intervals. Inventories before 1983 recognized three species' 

groups: pines (Pinus L. spp.), oak 

spp.), and other hardwoods. All s 

recorded by 1 lasses. 

group, gums ( L. and 

added to the inventory. 

Pine release study. Prior to release treatments in 

1939, all pines and hardwoods 4 inches in d. b. h. 

and larger were inventoried by 1 -inch d. b. h. classes 

on a plot-by-plot basis. Hardwoods were 

categorized as red oak, white oak, gum, and 

others. Records of harvested trees were kept by 

species' groups and number of trees cut by 1 -inch 

d. b. h. classes. The most recent inventory on these 

plots was conducted in 1986. 

Methods-of-cut study. Alt trees 4 inches in d.b.h. 

and larger were measured before and after each cut 

and categorized by 1 -inch d. b. h. classes on a plotby-plot basis. Species' ciassification was either 

pine or hardwood. The last inventory for purposes 

of this investigation was done in 1979. 

For all three studies, pine volumes were determined 

from loblolly-shortleaf volume equations (Farrar and 

others 1984). Hardwood volumes were obtained 

from a hardwood volume table for the Crossen Experimental Forest (Reynolds 1959). Volume production was determined as follows: 
Residual volume + cut volume - initial volume = 

volume production. 

In both the release study and the methods-of-cut 

study, analysis of variance was used to evaluate 

treatment differences for pine and hardwood. 

Duncan" multiple range test was used to partition 

mean differences among treatments. All analyses 

were conducted at the 0.05 level of significance. 

RESULTS AND DISCUSSION 

Timber Production 

Where pure pine was the principal goal of management, pine volume production tended to increase in 

all three investigations whenever competing 

hardwoods were effectively controlled (table 1 ). In 

the unmanaged stand, where there was no 

hardwood control, annual pine volume production 

averaged 43 percent less than the next lowest annual production, which was found in the pine 

release study. That lower volume in the pine 

release study occurred where the least intensive 

treatment involved cutting of only those overstory 

hardwood trees that were overtopping pine seedlings. The largest average annual sawlog production was in the methods-of-cut study using the 

selection system, which is rather intensive management by cyclic cuts at regular intervals. 

The highest average annual hardwood product ion 

on these upland pine sites occurred in the pine 

release study with a mean of 21 cubic feet per acre 

across the three treatments (table 1). Even though 

increasing intensity of pine release significantly improved the cubic-foot production of pines in that 

study, there were no statistically significant differences in hardwood production between treatments 

after 47 years. Because there were no sales of 

hardwood timber and thus no hardwood removal in 

the unmanaged stand, annual hardwood production was 71 percent less than the mean in the pine 

release study during a similar time intewal. 

Hardwood production data from the pine release 

study corroborate results of other investigations 

that have demonstrated the ability of indigenous 

hardwoods to rebound after repeated efforts at control (Cain and Yaussy 1983, 1984; Cain 1985). 

Such resilience provides landowners with an opportunity to manage their forest properties for both 

pines and hardwoods if their objective is the 

development of mixed stands. For example, in the 

Table 1.--Merchantable volume production from three long-term 

investigations in mixed pine-hardwood stands 

Mean volume production/acre year.?l/ 

Study designation Time 

and treatments interval Pine Hardwood 

Years Board feetw Cubic feet Cubic feet 

Unmanaaed ~tandH 46 120 3 2 6 

Pine ~eleaseu 4 7 

ROH 227a 56a 22a 

ROMH 279a 75 b 20a 

ROMUH 2 7 6a 77 b 2 la 

Error mean square 1,202 4 5 15 

~ethods-of -cut+ 3 6 

Selection 377a 84 b -- Diameter limit 330a 107a - - Heavy seed tree 362a 117a -- Patch clearcut 260 b 93 b 2 

Error mean square 766 4 6 -- 

giproduction = Residual + cut - initial. Means within columns by 

treatment and study are not significantly different at the 0.05 

level when followed by the same letter. 

E/Production data from Baker and Bishop (1986). 

UROH = Remove overstory hardwoods; ROMH = Remove overstory & 

midstory hardwoods; ROMUH = Remove overstory, midstory & some understory hardwoods. 

g/Production data for plots established in 1942 (Baker and Murphy 

1982). 
more intensively managed methods-of-cut study, 

the only increase in hardwood production in 36 

years was in the patch clearcut method, which was 

the only treatment to receive prescribed burning. 

Other studies have shown that single and periodic 

prescribed fires in natural stands of southern pines 

will increase the density, and therefore future 

productivity, of the hardwood component (Oosting 

and Livingston 1964; Cain 1985). 

Where management of the merchantable stand component was most intensive in these three studies, 

there was a general increase in submerchantable 

(stems less than 3.6 inches in d. b. h.) pine density. 

For example, all four treatments in the methods-ofcut study averaged about 3,000 stems per acre of 

pine reproduction 5 years after the initial harvest 

(Grano 1954). In the pine release study, the two 

most intensive treatments increased the number of 

free-to-grow pine seedlings so that ingrowth to merchantable size resulted in long-term pine volume 

gains (Cain 1988). In contrast, shade tolerant 

hardwoods predominated the submerchantable 

component of the unmanaged stand in the absence 

of disturbance (Cain 1 987). 

were generally determined by the degree of 

management imposed, data from these three investigations emphasize the wide range in density and 

basal area that is possible from mixed pinehardwood stands in a small geographic area where 

site conditions are uniform. For example, merchantable pine plus merchantable hardwood basal area 

ranged from a low of 29 square feet per acre on one 

treatment of the pine release study in 1939 to a high 

of 147 square feet per acre in the unmanaged stand 

in 1983. Similarly, merchantable pine plus 

hardwood density varied from 101 stems per acre 

in 1939 on the least intensive treatment of the pine 

release study to 281 stems per acre in 1979 on the 

clearcut treatment of the methods-of-cut study. 

Because of such variability, some measures of density or stocking are needed, measures that are not 

site specific, to serve as guides to forest managers 

who wish to achieve modest pine productivity from 

mixed pine-hardwood stands. Relative basal area 

of the pine and hardwood components might 

provide a useful stocking guide. To test that assumption, long-term trends from the present investigations were illustrated graphically by plotting 

relative basal area and relative density (trees per 

acre) of both the pine and hardwood components 

All three investigations presented in this paper were over time (figures 1 through 3). The most dramatic 

within 1 mile of each other on good sites in the trend was found in the unmanaged stand (figure 1). 

Upper Coastal Plain. Although forest stocking levels Relative basal area of pines (65 percent) and 

-dl- Density Hardwood Density 

Figure 1 .--Relative density and basal area for merchantable-size pines and hardwoods in an un- . . . 

managed stand between 1937 and 1983. -*--- Pine Basal Area - m-. Hardwood Basal Area 

I 

1937 1983 

YEAR 
80 Remove Dverstorv Hardwoods 

Figure 2.--Relative density and basal area for merchantable-size pines and hardwoods between 1939 

and 1986 by intensity of pine release. 

Pine Density 

- - * - Pine Basal Area 

--C Hardwood Density 

- a - Hardwood Basal Area 

1 939 1 986 

80 R~move Overgtnry & M~dslory Hordwcods I Remove Overstcry, Midstory and L Understory Hardwoads 

.-- -*-a - _--- __--- 

__-- 

--I. --- - ..- - . - - - _ - - 

--a 

20 1 ' I 18 I 

1939 1986 1939 1986 

YEAR 

YEAR 

hardwoods (35 percent) remained nearly stable 

over a 46-year period, but relative hardwood density increased with a concomitant decrease in relative pine density. The intolerant pines could not 

regenerate in competition with the more shadetolerant hardwoods in the absence of disturbance, 

but established pines continued to increase in 

diameter and maintain their basal area level. 

Similar trends in relative basal area were apparent 

in the pine release study where both pines and 

hardwoods were periodically hawested between 

1939 and 1965. Although pine production was improved with more intensive release (table I), relative 

hardwood basal area, before release and 47 years 

later, had a narrow range of from 26 percent to 45 

percent of the total (figure 2). The midpoint of that 

basal area range corresponds to the relative 

hardwood basal area (35 percent) in the unmanaged stand during a 46-year interval. 

Pretreatment relative basal area for hardwoods in 

all plots of the methods-of-cut study averaged about 

20 percent (figure 3). In that study, pine production 

was the principal goal of management. For the 

clearcut treatment, however, where there was no 

disturbance from management activities for 40 

years, relative hardwood basal area still averaged 

about 20 percent in 1979. Site disturbance from periodic harvesting at 5- to 15-year intervals in the 

heavy seed-tree, diameter-limit, and selection cutting methods resulted in a reduction of relative 

hardwood basal area to about 6 percent of the total 

in 1979. 

Long-term trends from these three investigations 

tend to support the following hypothesis. Relative 

basal areas between 20 and 45 percent for the 

hardwood component and between 55 and 80 percent for the pine component occurred in conjunction with different silvicultural treatments. 

Therefore, these relative basal area levels may 

provide a basis for perpetuating mixed pinehardwood stands where pine is the principal component. 

This hypothesis can be substantiated from 

published investigations within and outside the 

Upper Coastal Plain of the Southern United States. 

In southern Arkansas, for example, Cain (1 985) ex- 
Pi Density + Hardwood Density 

- -(I) - . Pine Basal Area - a - Hardwood Basal Area 

YEAR 

Heovy 5e~d Tree -+-- 

-/--* 

-__--- -__--- 

_--- ____----- *------- 

1979 1939 

YEAR 

0' ' I 

1939 1979 

YEAR 

1999 

YEAR 

Figure 3.--Relative density and basal area for merchantable-size pines and hardwoods by four 

methods of cutting, 1939 to 1979. 

amined the long-term consequences of hardwood 

control that began in 1954 in a 49-year-old, evenaged, natural stand of loblolly-shortleaf pines. 

Hardwoods were intensively controlled with 

prescribed fire or herbicides (cut-stump treatment 

or foliar application) between 1954 and 1961. 

Before treatment, total basal area had averaged 90 

square feet per acre with 14 percent in hardwoods 

and 86 percent in pines. In 1983, or 23 years after 

treatments ended, relative hardwood basal area 

averaged 22 and 21 percent respectively on the 

check and burn plots but only 6 percent on the herbicide treated plots. 

Halls and Homesley (1 966) described the composition of a mature pine-hardwood forest in the Coastal Plain of east Texas. An even-aged stand of 

loblolly-shortleaf pines had developed after oldgrowth pine timber was cut in the 1890's. There 

were recurrent wildfires until the 19301s, and larger 

hardwoods were cut or killed between 1938 and 

1950; otherwise the forest was undisturbed. When 

an inventory was conducted in 1963, pines were 70 

years old, and total basal area for pines and 

hardwoods was 125 square feet per acre with 73 

percent in pines and 27 percent in hardwoods. 

Schuster (1 967) characterized the structure of 

another natural, loblolly-shortleaf, pine-hardwood 

forest in east Texas. The virgin timber was cut 

around 1900, and salvage cuts of merchantable 

pines and hardwoods were conducted in 1940, 
1943, and 1946. In 1949, clearcut, selection, and 

shelterwood cutting methods were initiated for comparison with uncut areas. Ten years later, total pine 

and hardwood basal area ranged from 26 square 

feet per acre on the clearcut treatment to 96 square 

feet per acre on the uncut plots. Relative basal area 

for hardwoods was 30, 43, 36, and 77 percent of 

total on the uncut, sheltewood, selection, and clearcut plots respectively. 

Based on a 1938 inventory of a shorlleal-Virginia ' .6 pine ($. Milt.) stand in the Appalachian 

Highlands of Tennessee, Lange (1 951) found that 

the area contained a 26-year-old, even-aged mixture of pines that developed through a 41 -year-old 

hardwood understory as a result of fire. Basal area 

of pines and hardwoods averaged 107 square feet 

per acre with 72 percent of that in pines and 28 percent in hardwoods. 

Oosting and Livingston (1 964) studied the effects of 

a single ground and crown fire 29 years after the 

burning of a 35-year-old natural stand of loblolly 

pine in the southeastern Piedmont of North 

Carolina. At the time of their assessment, the unburned portion of the stand was 64 years old with 

no management before or after the fire. Relative 

basal area for stems 1 inch in d. b. h. and larger 

averaged 81 percent for pines and 19 percent for 

hardwoods, regardless of whether the plots were unburned or had been subjected to a ground- or 

crown-fire. 

In 1947, a study was initiated in the Cumberland 

Ptateau of nofikaern Atabama to appraise the efiects 

of stand improvement in pine-hardwood Forests that 

had been depleted by cutting and fire (Smatley 

1974). Before treatment, the merchantable portion 

of the stands consisted of 47 square feet of basat 

area per acre with 28 percent in pines and 72 percent in hardwoods. A combination of cleanings, improvement cub, libera"eion, salvage, and a few 

thinning%, all based on individual tree selection, 

rehabilitated the;? depleted stands so that relative 

hardwood basal area decreased from '92 percent of 

the total to less than 38 percent of the total within 

19 years 

There is a common thread that binds all of these investigations together. Relative hardwood basal 

area in mixed pine-hardwood stands across the 

South tended to range between 20 and 45 percent 

of the total basal area. "l"hese relative basal area 

levels were not achieved as quickly when merchantable timber was depleted or when there was intensive use sf herbicides lor hardwood control to 

enhance pine production. On the other hand, these 

levels were achieved on a variety of sites where 

there were periodic disturbances from harvesting 

activity or recurrent fires. Forest managers should 

therefore capitalize on any phenomenon that tends 

to perpetuate productivity from mixed stands. 

Forest management is needed to maintain stand 

conditions so that pines can survive and csetxist 

with the more aggressive hardwood species. If 

management by man is excluded from pine sites in 

the Southeast, and if succession proceeds without 

disturbance, hardwoods will eventually replace the 

pines, thus culminating in an oak-hickory climax 

forest (Oosting 1 956). 
LITERATURE CITED 

Boyce, Stephen G.; Knight, Herbert A. 1980. 

Prospective ingrowth of southern hardwoods 

beyond 1980. Res. Pap. SE-203. Asheville, NC: 

U.S. Department of Agriculture, Forest Service, 

Southeastern Forest Experiment Stat ion. 33 pp. 

Baker, James B.; Bishop, Larry M. 1986. Crossett 

demonstration forest guide. Gen. Rep. R8-GR6. 

Atlanta, GA: U .S. Department of Agriculture, 

Forest Service, Southern Region. 55 pp. 

Baker, James 8.; Murphy, Paul A. 1982. Growth 

and yield following four reproduction cutting 

methods in loblolly-shortleaf pine stands--a case 

study. Southern Journal of Applied Forestry. 6:66- 

74. 

Cain, Michael D. 1988. A low-cost technique for increasing pine volume production in mixed 

pine-hardwood stands. Res. Pap. SO-246. New 

Orleans, LA: U.S. Department of Agriculture, 

Forest Service, Southern Forest Experiment Station. 9 pp. 

Cain, Michael D. 1987. Survival patterns of understory woody species in a pine-hardwood forest 

during 28 years without timber management. pp. 

141 -1 47. In: Proceedings sixth central hardwood 

forest conference; 1987 February 24-26; Knsxville, TN. Knoxville, TN: University of Tennessee. 

Cain, Michael D. 1985. Long-term impact of 

hardwood control treatments in mature pine 

stands. Res. Pap. SO-214. New Orleans, LA: U.S. 

Department of Agriculture, Forest Service, 

Southern Forest Experiment Station. 8 pp. 

Cain, M.D.; Yaussy, D.A. 1983. Reinvasion of 

hardwoods following eradication in an unevenaged pine stand. Res. Pap. SO-188. New Orleans, 

LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station. 8 pp. 

Cain, M.D.; Yaussy, D.A. 1984. Can hardwoods be 

eradicated from pine sites? Southern Journal of 

Applied Forestry. 8:7-13. 

Farrar, Robert M., Jr.; Murphy, Paul A.; Willett, R. 

Larry. 1984. Tables for estimating growth and 

yield of uneven-aged stands of loblolly-shortleaf 

pine on average sites in the West Gulf area. Bull. 

874. Fayetteville, AR: University of Arkansas, 

Division of Agriculture, Arkansas Agricultural Experiment Station. 21 pp. 

Grano, Charles X. 1954. Re-establishment of 

shortleaf-loblolly pine under four cutting methods. 

Journal of Forestry. 52: 132-1 33. 

Karchesy, Joseph; Koch, Peter. 1979. Energy 

production from hardwoods growing on southern 

pine sites. Gen. Tech. Rep. SO-24. New Orleans, 

LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station. 59 pp. 

Lange, Keith D. 1951. Effects of clearcutting understory hardwoods on the growth of a shortleafVirginia pine stand. Journal of Forestry. 49:176- 

178. 

Oosting, Henry J. 1956. The study of plant communities. 2nd ed. San Francisco: W.H. Freeman 

and Co.: 288-289. 

Oosting, H.J.; Livingston, R.B. 1964. A resurvey of a 

loblolly pine community twenty-nine years after 

ground and crown fire. Bulletin Torrey Botanical 

Club. 91 (5):387-395. 

Porterfield, Richard L. 1984. A discussion of landowner attitudes. pp. 261-268. In: Karr, B.L., J.B. 

Baker, and T. Monaghan, eds. Proceedings of the 

symposium on the loblolly pine ecosystem (west 

region); 1984 March 20-22; Jackson, MS. [Available from Mississippi Cooperative Extension 

Service, Mississippi State, MS]. 

Reynolds, R.R. 1959. Eighteen years of selection 

timber management on the Crossett Experimental 

Forest. Tech. Bull. 1206. Washington, DC: U.S. 

Department of Agriculture, Forest Service. 68 pp. 

Schuster, Joseph L. 1967. The relation of understory vegetation to cutting treatments and habitat 

factors in an east Texas pine-hardwood type. The 

Southwestern Naturalist. 1 2(4):339-364. 

Smalley, Glendon W. 1974. Development of pinehardwood stands in north Alabama following 

improvement cuttings. Res. Pap. SO-1 00. New Orleans, LA: U.S. Department of Agriculture, Forest 

Service, Southern Forest Experiment Station. 9 

PP. 

U.S. Department of Agriculture. 1979. Soil survey of 

Ashley County, Arkansas. USDA Soil Conservation Service and USDA Forest Service in 

cooperation with Arkansas Agricultural Experiment Station. 92 pp. 

Halls, L.K.; Homesley, W.B. 1966. Stand composition in a mature pine-hardwood forest of 

southeastern Texas. Journal of Forestry. 64:170- 

174. 
DYNAMICS OF MIXED PINE-HARDWOOD STANDS THAT 

DEVELOP FROM HARDWOOD ENCHROACHMENT IN PINE 

PLANTATIONS 

W. D. Smith, W. L. Hafley, and T. A. ~ierauf' 

.-Interest in the management of mixed pine-hardwood stands has increased the need 

for the development of growth and yield models for mixed stands, Smith and Hafley (1 987) used 

a simulation approach based on independently developed pine plantation and natural hardwood 

models to develop a model for such stands. Output from the model supported by long-term 

measurements from permanent plots in pine plantations that contain a significant hardwood component are used to evaluate the changes in species composition over time. 

INTRODUCTION 

Interest in modeling the growth and development of in figure 1, indicate that hardwood composition 

pine plantations that have a significant hardwood decreases dramatically after the initial period of 

component has increased greatly in recent years. encroachment and then increases over time. This 

Assessing the economic impact of hardwood behavior, as will be discussed later, is expected 

encroachment on pine production was the initial given basic ecology and the relative growth habits 

motivation. But increased recognition of the nontim- of the species. 

ber amenities of mixed stands has expanded this interest. ""T 

Evaluation of the productivity of timber and nontimber products from mixed stands is facilitated by the 

use of growth and yield models. Development of 

such models requires (1) an understanding of 

stand growth and ecology, both as pure stands and 

in mixtures, (2) the development of mathematical 

functions that describe the biological relationships, 

and (3) long-term measurement of mixed stands to 

estimate model parameters. Unfortunately, very little data exist on the growth of pine plantations with 

a hardwood component. Although many studies 

have been established to assess the impact of 

hardwood on pine growth, very few provide information on either the initial hardwood composition or 

its subsequent development over time. This limits 

the development of an understanding of stand 

growth and ecology and makes the direct estimation of parameters for growth equations difficult. 

Smith and Hafley (1987) used a simulation ap- Age 

Figure 1 .--Predicted percent hardwood basal area proach based on independently developed planted over time from the NCSU model. pine and natural hardwood models to model the 

development of such stands. The pine plantation Details of the model development and preliminary component was the North Carolina State University verification using a 24-year-old site preparation Plantation Management Simulator, and the study located at Fayette, Alabama provided by the hardwood component was developed by Zahner Auburn University Silviculture Herbicide Coopera- and Myers (1984) for young Piedmont oak stands tive are contained in the papers cited. However, in of sprout origin. Results of the model, as presented the Fayette data the first measurement of hardwood 

composition was not made until age 12, after the 

'~ssistant Professor, Department of Forestry, North 

Carolina State University, Raleigh, NC; Professor, Department of Forestry, North Carolina State University, 

Raleigh, NC; and Chief, Applied Forest Researdh and 

Reforestation, Commonwealth of Virginia, Department of 

Forestry, Charlottesville, VA. 

most significant changes in composition take place, 

and no other measurements were made until age 

24. The Virginia Department of Forestry (VDF) established a series of paired plots in pine plantations 
on cutover sites. Average age at the initial measurement was 3 (ages 2 to 4) and the plots were 

remeasured at 4-year intewals. Final measurement 

was a age 19 (ages 18 to 20). In this paper the 

results of VDF plots ai8 used to examine the 

dynamics of hardwood encroachment into pine 

plantations and to verify empirically the change in 

species composition exhibited by the model. 

&COL&%G"Valv DEVELOPMENT OF 

PINE-HARDWOOD STANDS 

Although knowledge in the development of 

hardwood encroachment into pine plantations is 

limited, the development of natural pine-hardwood 

stands that result frsm old field succession is a fundamental concept sf plant ecology. The gradual 

change from pine to hardwood is presented in 

table 1 from Oosting (1942). Percent hardwood increases over lime until, if undisturbed, a pure 

climax hardwood forest develops. The partern, 

however, that develops in pine plantations established afier harvesting a mixed natural stand 

without intensive site preparation is considerably different. The change in species composition, 

predicted by the model (figure I), indicates a rapid 

decline in percent hardwood until about age 3 8, it 

reaches a minimum at about age 20, and ahen increases t hereaMer. 

Table P,--manw in hardwood composition over time FOB 018 

field succession (date taken from Bostfng 1942) . 

Percent total Percent total 

Am of stmd density basal area 

11 years 0.0 Q. 0 

22 years 34.7 3*7 

31 years 48.5 2.2 

34 years 63.2 11.7 

42 years 23.4 1.9 

75 years 77.9 6.2 

110 years 93 4 12.0 

Poet climax 98.5 99.3 

Percent hardwood composition in six sf the check 

plots from the VDF data is ploMed against age in 

figure 2. Average hardwood composition at the 

rime of the initial measurement, age 3, was 91.2 percent, however 4 years later it had declined ts 58.5 

percent and by the last measurement, age 4 9, to 

43.1 percent, This behavior is in agreement with 

the change in hardwood percent (presented rn table 

2) sbsewed at the Fayette Alabama study, The 

average percent decline in percent haadvdsod From 

age 12 to 24 in the Fayege study was 16 percent. 

Over a simitiar period in Ehe VDF study, age 9 to 75, 

the decline was 20 percent. Although data in plantations does not exist to verify the increase in percent hardwood in later years as is indicated by the 

model and as occurs in old field succession, it was 

not unexpected given the normai grsMh habit sf 

oak. In general, oak reaches the rapid gromh 

stage afier the gro\Pd(ih sf pine culminates, 

Figure 2.--Actual hardwood basal area over time for 

the check plots from the VDF data. 

oA:::;::;::::::::;::::::::t 5 10 15 20 25 

Age 

- Pine plant "- Oak sprout - Oak natural 

Figure 3,--Comparison of dominant height of 

planted lobtally pine with oak from seedling and 

sprout origin. 

Table 2,--Change in hardwood coatposition from age 12 to 24 

for the Fayette, Alabama Study 

Site preparation Percent hardwood Percent hardwood 

treatment age 12 age 24 

Bulldozed 10.0 9.0 

Injection 23.0 14 .O 

Hand Girdled 40.0 38.0 

Ax Frill 21.0 9 0 

Check 83.0 84 .O 

Data provided by Auburn University Herbicide Cooperative 
This difference in growth pattern between mixed 

stands that develop by old field succession and 

hardwood encroachment in pine plantations established on cutover sites is explained by the origin of 

the hardwoods. On oid fields the hardwoods 

develop from seed origin while on cutover sites the 

hardwoods develop from sprouts or advanced 

regeneration. The comparative height growth of 

natural oak (Olson 1959), oak of sprout origin, and 

planted loblolly pine (Golden and others 1981) on 

lobtolly pine site index 60 base 25 are presented in 

figure 3 The equivalent base age 50 is site 92 for 

pine and site 84 for oak. The natural oak curve exhibits the slow early height growth, 3 feet at age 5, 

typical of oak seedlings while the sprout curve 

demonstrates the rapid early growth of oak stems 

of sprout origin. In old field succession the pine is 

much taller than the oaks of seedling origin and oak 

will not dominate the site until after senescence of 

the pine. In contrast the planted pine is much 

shorter than the oak sprouts at age 5. The pine will 

catch up to the oak by age 20 and will, as indicated 

by the difference in site index base 50, exceed the 

height growth of the oaks. The development of VDF 

data is consistent with this pattern. Dominant 

height of oak, although measured on only one plot, 

was 40 feet at age 19 compared with 37 feet for 

pine. 

COMPARISON OF THE MODEL WITH THE VDF 

DATA 

A comparison of the model predictions with the observed results from the VDF study are presented in 

table 3. Predictions were based on the initial and 

projected to age 19. 

Table 3.--Comparison of model projection from stand conditions 

at age 7 to age 19 with actual for 15 plots from the VDF data. 

Average Percent 

Average Absolute Explained 

Variable Difference Range Difference Variation 

Pine T/A 7.0 -99to217 56.0 75.2 

Pine Dbh (in) .o -.6 to .6 -4 69.3 

Pine BA (sqft) -3.4 -28 to 16 10.8 88.0 

HdwdBA (sqft) 3.5 -9to16 6.5 83.2 

Percent Hdwd 1.1 -20 to 13 5.4 88.0 

Difference = Observed - Predicted 

Percent Explained Variation = 1 - Difference Squared/Total 

Adjusted Sum of Squares 

Expressed as a Percent 

hardwood is constant over time. The error in 

prediction when percent hardwood is assumed constant ranged from 20 to 60 percent underestimates 

of pine volume and corresponding overestimates of 

hardwood volume. It is of equal importance when 

making management prescriptions. Changes are 

most rapid at young ages when manipulation of 

species compostion is most effective. 

Table 4. --Comparison of projected volume at age 30 given 

percent hardwood at age 5 with projected volunre assuming no 

change in percent hardwood. 

Percent Percent Volume (cffac) Volume (cf f ac) age 30 

Hardwood Hardwood age 30 no change in Percent 

Hardwood 

age 5 age 30 Pine Hdwd Pine Hdwd 

LITERATURE CITED 

Golden, Michael S.; Meldahl, Ralph; Knowe, Steven 

A.; Boyer, William D. 1981 . Predicting site index 

for old-field loblolly pine plantations. Southern 

Journal of Applied Forestry 5(3): 109-1 14. 

Smith, W. 5.; Hafley, W. L. 1987. Simulating the effect of hardwood encroachment on loblolly pine 

plantations. pp. 180-1 86. In: Proceedings of the 

fourth biennial southern silvicultural research conference; 1986 November 4-6; Atlanta, GA: Gen. 

Tech. Rep. SE-42. Asheville, NC: U.S. Department 

of Agriculture, Forest Service, Southeastern 

Forest Experiment Station. 

Olson, D. J., Jr. 1959. Site index curves for upland 

oak in the Southeast. Res. Note 125. Asheville, 

NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station. 

2 PP. 

Oosting, Henry J. 1942. An ecological analysis of 

the plant communities of Piedmont, North 

Carolina. The American Midland Naturalist 

28(1) 11 -1 26 

Zahner, Robert; Myers, Richard K. 1984. Productivity of young Piedmont oak stands of sprout 

origin. Southern Journal of Applied Forestry 

8(2): 102-1 08 

CONCLUSIONS AND MANAGEMENT Zahner, Robert; Myers, Richard K.; Churchill, Lisa 

lMPLICAf lONS A. 1982. Site index curves for young oak stands 

The most significant result obtained from the VDF of sprout origin. Clemson University, Department 

data is additional verification of the predicted of Forestry, Forestry Bulletin Number 35. 2 pp. 

change in hardwood composition by the model. 

The importance in recognition of this behavior in 

yield forecasting is demonstrated in table 4. The 

projected total yield of both pine and hardwood 

using the model is compared with a growth projection based on the assumption that the percent 
DEVELOPMENT AND APPLICATION OF A VARIABLE 

DENSITY YIELD MODEL FOR MIDSOUTH 

PINE;-HARDWOOD STANDS 

John F. ell^' 

.-The development and application of a recursive equation system to predict future 

volumes for mixed-aged, pine-hardwood stands is described. The model was developed using 

data from permanent plots remeasured as part of the ongoing forest survey of the USDA Forest 

Service in Midsouth states. Coefficients are presented for 3 different site classes in the East Gulf 

Coastal Plain region. Appiication of the model requires the basal area and number of growingstock trees, saplings, cull trees, and the percent of pine basal area. The model accounts for the 

average amount of mortality; stands with declining volumes were excluded from model development, 

INTRODUCTION 

A large portion of the Midsouth's forests is com- opportunity cost if their conversion to natural pine 

prised of mixed, uneven-aged stands. Almost one- or pine plantations is considered. The updating 

fifth of the timberland in the 7-state Midsouth area is and projection of forest inventories is an important 

classified as mixed pine-hardwood forest type, issue both regionally and nationally; due to the 

where pine comprises 25-49 percent of the stocking large area they occupy, mixed stands must be effec- 

(Birdsey and MeWilliams 1986). In addition, there tively dealt with to insure the validity of these proceare large portions of natural pine and upland dures. 

hardwood forest types that have a significant component of hardwood, or pine, respectively. Currently, there are 44 million acres of upland pine sites in 

the 7 Midsouth states that support mixed-aged 

stands (table 1). These stands have two or more 

distinct age classes that are at least 10 years apart. 

This estimate excludes upland hardwood sites not 

favorable for pine growth. 

Table 1.--Timberland area, in the Midsouth, of mixed-aged stands 

on pine sites, by State, latest survey. 

State 

Alabama 

Arkansas 

Louisiana 

Mississippi 

Oklahoma 

Tennessee 

Texas 

All States 

Date of 

survey Timberland area 

Thousand acres 

Although the development of mixed-aged, pinehardwood stands may not be a goal of forest 

managers, information about the growth of these 

stands is important. This importance stems not 

only from the wide area covered by these stands, 

but also due to the increasing interest of forest 

managers in applying economically sound silvicultural practices. Often, the maintenance of mixedaged, pine-hardwood stands may be an important 

There have been several studies of growth and yield 

applicable to the South, but most have dealt with 

even-aged pine stands. Some studies have concerned hardwoods as well, but there has been a 

lack of stand-level models dealing with mixed-age, 

pine-hardwood stands. 

The nation-wide forest inventory and analysis (FIA) 

was established as a responsibility of the USDA 

Forest Service originally in 1928 by the McSweeneyMcNary Act. Subsequent laws have continued and 

extended this function. Over the years, FIA plots 

have been installed and remeasured, primarily to 

determine volume and changes in the timber 

resource. These plots also provide an opportunity 

to develop information on growth and yield for a 

variety of stand conditions. Murphy (1 982, 1983) 

and Murphy and Beltz (1980) have used these data 

for yields of even-aged stands of loblolly pine and 

shortleaf pine. Studies in other regions have used 

FIA data to develop yield information in tabular 

form, such as Hahn and Stelman (1 984), and McClure and Knight (1 984). 

A number of factors make pine-hardwood stands in 

the South more difficult to analyze than others. 

Chief among these factors are (r ) stand structures, 

which are often neither even-aged, nor unevenaged (characterized by having 3 or more age classes distributed in an orderly fashion); and (2) the 

heterogeneity of species. Data from remeasured 

FIA plots in the Midsouth offers an opportunity to explore the development of a volume-prediction 

'~ohn F, Kelly is Research Forester, Southern Forest 

Experiment Station, USDA Forest Service, Starkville, 

MS. 
model for these typical stands. The purpose of this 

paper is to develop a volume prediction model for 

mixed-aged pine-hardwood stands using data from 

remeasured FIA plots in the Midsouth. 

FBRESnNVENTORY PROCEDURES 

The Southern Forest Experiment Station, Forest I nventory and Analysis unit (SO-FIA) remeasures permanently established plots on a periodic basis. 

SO-FIA procedures include classification of trees as 

either growing stock or cull with volume calculations accomplished for growing-stock trees at least 

5.0-inches diameter at breast height (d bh). Basal 

area is calculated for trees 1 .O-inches dbh and 

larger. 

Forest sites are classified by productivity class, 

based on the best site index trees available - regardless of species. Sites are also classified according 

to physiography and potential for pine growth; the 

specific categories for this classification are pine 

sites, upland hardwood sites, and bottomland 

hardwood sites. Only pine sites were used in this 

study. 

SO-FIA cruisers assign an tige to individual stands - 

but only if a single tree age is present. The 

presence of 2 or more distinct age classes will result 

in a mixed age classification. 

As plots are remeasured, a tree history code is used 

to account for individual trees tallied in the initial 

suwey. These tree history codes indicate trees that 

have been cut, died, or suwived during the inter-survey period. Accounting for trees in the initial 

measurement thus allows the calculation of change 

data, such as growth, removals, and mortality; the 

records also maintain information about the stand 

at both the initial and final periods. 

DATA FOR MODEL DEVELOPMENT 

SO-FIA data were selected for model development 

to include plots in the East Gulf Coastal Plain; areas 

in the predominantly longleaf-slash pine region near 

the coast were excluded (figure 1 ). These plots 

were screened to include only mixed-aged stands 

on upland pine sites. Furthermore, plots with the 

following characteristics were excluded: stands with 

any eastern redcedar component; plots with any 

timber removals over the survey cycle; and plots 

that were othewise showing a decline in volume. 

Finally, plots were required to have at least 10 

square feet basal area of growing stock. The plots 

selected range from pure hardwood stands to pure 

pine stands, with the vast majority having some mix 

of pine and hardwood. 

Portions of Alabama, Mississippi, and Louisiana 

were included in the study. SO-FIA data are availIS in the 
able for these states covering 3 surveys. Data for 

Alabama are availabte for surveys in 1963, 1972, 

and 1982; Louisiana data are available for 1964, 

1974, and 1984; and Mississippi data covers 196'7, 

1977, and 1987. The data were assembled so that 

attributes could be gauged over an approximate 20- 

year period for qualifying plots - those with at least 

7 0 square feet of initial basal area, no timber 

removals during the interim, etc. The data from the 

20-year period were then pooled with the data from 

the most recent 10-year period in order to provide 

differential time periods. In actuality, the elapsed 

time between measurements for the short-cycle 

data ranged from 8.1-1 0.6 years, while the elapsed 

time for the long-cycle data ranged from 17.5-21.2 

years. 

cubic feet and higher. Loblolly pine site indexes 

(50-year basis) correspond approximately to these 

site classes as follows: low, 60-79; medium, 80-94; 

and high, 95 and above. In order to concentrate on 

stand conditions influencing stand growth, separate 

models were estimated for these 3 site classes. 

MODEL DEVELOPMENT 

Most stand-level yield models deal with even-aged 

stands through estimation of grotstith-rate equations 

integrated over a specified time period (age). An example of these models is Clutter (1 963); other 

studies have used a modification of this approach. 

Moser and Hall (1969) have modelled growth in uneven-aged stands. This latter model uses periodic 

change in both basal area and volume as predictor 

variables for yield over an elapsed time, instead of A total of 672 plots was utilized, with about half 

(320) remaining undisturbed over the 2 survey age. The model was applied to a single stand of 

mixed hardwood in Wisconsin. periods. For the pooled data set, initial basal area 

of growing stock ranged from 11 to 183 square feet 

per acre, with an average of 61. Pine basal area as 

a percent of total pine basal area averaged 36 percent. Initial quadratic mean d bh of growing-stock 

trees averaged 5.4 inches. Table 2 shows the distribution of plots in the pooled data set by site, 

mean diameter of volume trees, and basal area of 

growing-stoc k trees. 

Since a variety of species was used to determine 

site quality, the standard FIB site class variable was 

Mixed-aged, pine-hardwood stands are composed 

of many species differing greatly in their tolerance. 

The pines are intolerant and may be somewhat 

tolerant at early age; the hardwoods vary widely in 

their tolerance by species. Moreover, this stand 

classification is often used for stands that do not fit 

more precisely defined categories. This classification is thus a bewildering collage of stands comprised of widely varying species compositions and 

stand structure conditions, 

used: To facilitate model development. 3 sites were Due to this complexity, yield functions consisting 

designated: low, representing potential productivity only of growt h-rate equations which are integrated 

for fully stocked natural stands of 50-84 cubic feet over an elapsed time may not account for potential 

per acre per year; medium, representing potential variability from stand to stand. Additional informaproductivity of 85-1 19 cubic feet; and high, 120 tion relating to specific stand structure and species 

Table 2.--Sample plot distribution by site, mean diameter, and basal area at 

initial period. 

C 

Basal area per acre 

Mean 

~i tea diameterb 10-25 25-50 50-75 75-100 100+ Total 

Low No trees 7 3 0 0 0 10 

5-10 25 5 3 38 16 5 137 

10 + 6 12 14 3 0 35 

Total 38 68 52 19 5 182 

Medium No trees 0 2 0 0 0 2 

5-10 36 77 8 1 56 26 276 

10 + I 1 24 20 18 12 85 

Total 47 103 101 74 38 363 

High No trees 1 1 0 0 0 2 

5-IG 29 63 80 57 39 274 

10 + 10 32 4 o 45 30 157 

Total 40 96 126 102 69 433 

a~ite quality is based on culmination of mean annual growth in fully stocked 

natural stands as follows: low sites, 50-84 cubic feet per acre per year; medim 

sites, 85-119; and high sites, 120 and higher. 

'~ean diameter of tree of average basal area for trees at least 5.0-inches dbh. 

-Includes growing-stock trees at least 1.0-inches dbh. 
composition may be more effective. An effective 

model would be able lo deal with varying stand 

structures and the mix of species. 

The first step in developing a volume prediction 

model deals with selecting an equation to estimate 

Ev2) = expected (predicted) cubic foot volume, inside bark, of grswing-stock trees at least 5.0 inches 

dbh, on a per acre basis for final time period: 

B2 = basal area, in square feet per acre, of 

growing-stock trees at least 5.0 inches dbh 

ha2 - dbh sf the tree sf average basal area, for trees 

at least 5.0 inches dbh; also know as quadratic 

mean diameter 

aa, a 1, a2 - regression coefficients to be estimated. 

This stand volume equation is related to the 

diameter-diameter squared individual tree volume 

equation suggested by Cunia (1 964). 

Obviously, 82 and D2 must now be estimated in 

order to predict Va. The following equations were 

formulated to account for the silvical factors affecting changes of B2 and 192 over time: 

where: 

BGSl =basal area, in square feet per acre, of growing-stock trees at least 1.0 inches d bh for the initial 

period 

PPN I = proportion of pine basal area relative to 

total live basal area (including cull trees) for ail trees 

1 .B inct-res dbh and larger 

DI = qbtadraric mean dimeter for growing-stock 

trees 5.0-inches dbh and larger 

TS1 - ntrmber of sapling growing-stock trees (1.8- 

4 9 inches dbh) 

BLVl =: basal area af %It live trees at least 1.0-inches 

d bh 

T =elapsed time; in years, of the volume prediction 

period. 

bi, cl = regression coefficients to be estimated 

"da~iabies BGSl, XI, and BLVl deal with stand 

structure, as it relates lo suwivor growth, potential 

ingrowth of volume trees, and total stocking. PPNl 

accokinb for relative presence of pine. Site is 

not included as a variable, since the discreet site 

classes used by SO-FIA would be inappropriate for 

direct incorporation in a linear model; separate estimations were accomplished for each site class. 

Equations (1 ), (21, and (3) thus form a recursive system of equations that may be used to predict s%and 

volumes for a specified elapsed time. The system 

contains 3 endogenous variables fu'2, B2; and Dz), 

and 6 predetermined variables (BGSI, PPN1, 191, 

TS1 and BLVl, and T). Ordinary least squares may 

be applied to each equation separateiy to solve a 

recursive system (Gujarati 1978) Thus, equations 

(2) and (3) are first solved, then the results are used 

to solve equation (1 ) . 

RESULTS 

The results from the regression analysis are shown 

in table 3; separate coefficients are provided for 

low, medium, and high site classes. The plorting sf 

Table 3.--Estimates of model coefficients and their standard 

errors for low, medium, and high sites. 

Parameter 

B 

Estimate 

Low sites 

Medium sites 

High sites 

-- Standard esror 

"AIL parameter estimates are siwificmt at the .05 pro%saki.J~ty 

level. 
residuals indicated no discernable violations of assumptions inherent in the linear model. Possible 

collinearity between explanatory variables in the 

equation system was investigated by linear regression. The strongest linear correlation was between 

Dl and TS1 in equation (31, but this was deemed 

weak; furthermore, the variables actually represent 

separate parameters of different, albeit related, components in the stand. 

The effectiveness of the equation system is indicated in table 4. Deviations from the mean 

predicted values are presented as root mean 

square errors and coefficients of variation. 

Table &.--Model estilpation errors. 

Equation and 

Site variable 

f4eana 

value 

~oot meana 

square error 

Low 

Medium 

High 

Coefficient 

of variation 

(Percent) 

42.2 

34.0 

19.6 

34.8 

28.2 

15 .O 

29.2 

23.4 

14.6 

%Z is in cubic feet; B in square feet; and D2 in incies dbh. 2 

These equations accounted for the following percent of the variation in stand volumes at the final 

period: low sites, 54.5; medium sites, 54.4; and 

high sites, 62.2. 

APPLICATION OF THE MODEL 

Application of the model requires current stand 

data for the following items: (1 ) total basal area and 

number of merchantable growing-stock trees 

those at least 5.0-inches dbh; (2) total basal area of 

growing-stock trees at least 1 .O-inches dbh, for both 

pine and all other species; (3) the number of sapling growing-stock trees (1 .O-4.9 inches dbh); and 

(4) the basal area of cull trees at least 1 .O-inches 

dbh. These data are then used to develop the explanatory variables in equations (2) and (3). The 

quadratic mean diameter of merchantable growingstock trees (Dl ) is computed as a function of basal 

area and number of trees. 

For application of the model on medium sites, basal 

area and mean diameter are predicted with the following equations: 

After computing estimated values for B2 and D2, the 

projected volume is calculated by the following 

equation: 

As an example, suppose a predicted volume for 20 

years hence is needed for a stand on a medium site 

(loblolly pine site index 80-94, 50-year basis) with 

the following characteristics on a per acre basis: 50 

square feet of total live basal area, consisting of 5 

square feet of cull trees, 15 square feet of pine and 

38 square feet of basal area in merchantable growing-stock trees (at least 5.0-inches dbh); the stand 

has 125 growing-stock trees of merchantable size, 

and 150 growing-stock trees of sub-merchantable 

size. Initial volume is estimated at 200 cubic feet 

per acre. First, the quadratic mean diameter of the 

current volume trees (01) should be calculated. 

This is done as follows: 

= 7.5-inches dbh 

The proportion of pine growing stock is also determined: 

Then, equations (4) and (5) are solved: 

= 71.34 sq. ft./acre 

= 9.7-inches dbh 

Finally, the predicted volume equation is solved: 

= 1,577 cubic feetlacre 

Given the initial volume of 200 cubic feet per acre, 

the stand has produced 1,377 cubic feet in 20 

years, for an annual average growth of 69 cubic feet 

per acre. 

Other equation coefficients presented in table 3 

may be used similarly to provide estimates of 

volume for low and high sites. It should be noted 

that the V2 equation is to be used to estimate 

predicted volumes, not current estimates. 
Figure 2 shows the relationship of predicted values 

to elapsed time for average stand conditions existing at the time of initial measurement for the 3 site 

classes. Table 5 shows the average stand conditions for plots in the data set. 

- LOW - MEDIUM 

- HiGH 

2505 f 4 

-c--- 

U) / I I 

(r 

2050 1 J ---- 

0 5 10 15 20 25 

ELAPSED TIME (Years) 

Figure 2.--Relationship of predicted volumes to 

elapsed time for average stand conditions at initial 

measurement, by site class. 

Table 5.--Mean values for stand variables for plots in the 

data set, by site class. 

Site class 

Variable and unit Low Medium High 

BGSl (sq. ft/ac.) 47.6 59.4 67.8 

PPNl 

Dl (inches dbh) 

TS1 (numbers) 437 451 435 

BLVl (sq. ft./ac.) 60.8 72.8 83.4 

The model does not provide separate estimates of 

pine and hardwood volume; an extension of the 

model is planned that will accomplish this. Users 

may, however, make independent estimates of the 

proportion of pine volume at the predicted time. 

CONCLUSION 

The model presented here for prediction of future 

timber volumes for mixed-aged stands on upland 

pine sites accounted for 54-62 percent of the variation in stands located in the East Gulf region of the 

Coastal Plain. Other models dealing with evenaged pine stands typically account for more variation; they should be used where applicable. Since 

observations for the stands included in the study 

were accomplished for only 3 time periods covering 

a minimum of 8 years and a maximum of 21 years, 

the model is valid only for limited projection periods 

- perhaps a span of 5-25 years. 

It should be noted that the models account for an 

average amount of mortality. However, stands 

declining in volume - showing a negative growth 

rate - were excluded from the data and model estimation. The presence or absence of large 

amounts of mortality could be a major factor in actual volume yields. 

Further development does need to be done before 

it is fully satisfactory in many situations. The model 

needs to be extended to estimate pine and 

hardwood volumes separately. Also, as forest surveys continue across the M idsout h, additional data 

may be incorporated to strengthen the parameter 

estimates, especially over longer periods of time. 

LITERATURE CITED 

Birdsey, Richard A.; William H. McWilliams. 1986. 

Midsouth forest area trends. Resour. Bull. SO107. New Orleans, LA: U.S. Department of 

Agriculture, Forest Service, Southern Forest Experiment Station. 17pp. 

Clutter, J. L. 1963. Compatible growth and yield 

models for loblolly pine. For. Sci. 9:354-371. 

Cunia, T. 1964. Weighted least squares method 

and construction of volume tables. For. Sci. 

10: 180-1 91. 

G tijarati, Damodar. 1 978. Basic econometrics. 

New York: McGraw-Hill, Inc. 462 pp. 

Hahn, Jerold T.; Joan M. Steiman, 4984. Empiricai 

yield tables for Michigan. Gen. Tech. Rep. NC96. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station. 33 pp. 

McClure, Joe P.; Herbert A. Knight. 1984. Empirical yields of timber and forest biomass in the 

Southeast. Res. Pap. SE-245. Asheville, NC: 

U. S. Department of Agriculture, Forest Service, 

Southeastern Forest Experiment Station. 75 pp. 

Moser, J. W., Jr.; 0. F. Hall. 1969. Deriving growth 

and yield functions for uneven-aged forest 

stands. For. Sci. 15: 183-1 88. 

Murphy, P. A.; R. C. Beltz. ' 1981. Growth and yield 

of shortleaf pine in the West Gulf Region. New Orleans, LA: U.S. Department of Agriculture, Forest 

Service, Southern Forest Experiment Station. 

15 PP. 

Murphy, Paul A. 1982. Sawtimber growth and 

yield for natural, even-aged stands in the West 

Gulf. Res. Pap. SO-181. New Orleans, LA: U. S. 

Dept. of Agric., Forest Service, Southern Forest 

Experiment Station. 13pp. 

Murphy, Paul A. 1983. Merchantable and sawtimber volumes for natural even-aged stands of 

loblolly pine in the West Gulf region. Res. Pap. 

SO-1 94. New Orleans, LA: U. S. Dept. of Agric., 

Forest Service, Southern Forest Experiment Station. 38 pp. 
UNKING STANDLRIEL AND INDIVIDUAL-TREE GROWTH 

SIMUtATORS FOR MIXED SPECIES STANDS 

F. Thomas ~lo~d' 

. -Growth and yield information will be needed to manage the pine--hardwood type. This 

paper reports on the early stages of a major research effort to develop a growth and yield forecasting system for pine-hardwood mixtures and outlines the steps being taken to develop supporting 

data bases needed to calibrate the system. It is not a discussion of a working model. Rather, it 

lays out principles on which the research is being built and describes in broad terms how modeling will proceed. 

lNTROD19C"blON 

Various mixtures of yellow pine and hardwood are 

recognized as common stages of succession following forest disturbance in the South. Traditionally, silviculturalists have viewed these stands as prime 

candidates for conversion to pure pine. As a result, 

pine-hardwood mixtures have not been studied as a 

management type. Papers at this symposium 

demonstrate that there are a lot of reasons for considering management of pine-hardwood mixtures 

and that such management will require certain 

kinds of research. 

One pressing need is for information on growth and 

yield of pine-hardwood mixtures. Very little information is available in the literature, and what has been 

published has come from pine management studies 

that either by chance or design had hardwoods 

relegated to an understory status (e.g., Burkhart 

and Sprinz 1984, Smith and Hafley 1987). Studies 

have not been designed to evaluate growth characteristics in overstory mixtures of even-aged pine 

and hardwood. The goal of the research I propose 

is to develop a suitable system for forecasting 

growth and yield of mixed stands. In this paper I 

discuss the envisioned modeling approach and 

briefly describe initial field studies. By necessity, 

the exposition glosses over specific model constructs and associated calibration details. 1 also 

recognize that what apparently are viable assumptions and approaches may prove to be false or unworkable. 

MODEL PRECEPTS 

Rstafion-tength grovvth and yield models traditionall y predict stand-level anributes such as 

mean stand diameter, total basal area, volume, and 

the number of surviving trees for species monocultures. Considerable research has also gone into 

breaking down these stand-level statistics into 

' Project Leader USBA Forest Service, 

Seurheastern Forest Experiment Stat~on, Glemson 

S C 

diameter class frequency distributions. Even for 

monocultures, the complexity of this disaggregation 

process is considerable, and it is greater when 

modeling mixed species stands because of the 

need to predict by species group. The selection of 

appropriate groupings is an early requirement. 

Precept one is that species grouping will be 

based on a combination of shade tolerance, joint 

occurrence, on specific site types, and the 

similarity of growth patterns within groups. Final 

refinements to group composition will be determined by prediction objectives. For example, 

development of the pines is Important because of 

their high stumpage value, so pine might be split 

from a broader group of intolerant species. 

Site-specific differences in height growth are anticipated and will be among the growth criteria used 

in species group formation. For example, early 

height growth of hardwoods generally increases 

more than pine height growth as site type progresses from xeric to mesic conditions. Composition of 

the hardwoods also changes across the moisture 

gradient, so species groups probably will differ between site types. It is difficult to incorporate all 

height complexities found over the range of site conditions being considered because of limits to the 

flexibility of the mathematical constructs needed to 

describe the process. Precept two is that modeling can be simplified by building separate sets 

of height growth curves for specific site types 

defined across a moisture gradient. A description of the classification system that will identify the 

site-quality gradient to be used in this research is 

given by Jones (1 989). 

Precept three is that at any given time growing 

space used by one species or species group in a 

mixed stand is not available for other species or 

species groups. The challenge here is not in accepting the validity of this foundational concept, but 

rather in quantifying its effects. The model constructs must mimic annual growth trends brought 
about by crowding. A sound basis for incorporating these trends is contained in the limiting size 

boundary of the -3/2-power rule. This rule (or lawlike constraint) says that over time competition for 

growing space will increase, mortality (or self-t hinning) will begin as competition intensifies, and 

growth in average tree size will slow precipitously if 

self-thinning is allowed to progress undisturbed. 

Rotation-iengt h models estimate stacking with poor 

precision and/or contain bias due to the irregularity 

of mortality. The problem is considered inconsequential when performing broad forest management decision analyses and regional economic 

evaluations over large areas. However, similar 

analyses for forestry enterprises and individual 

forest landowners require more precise and accurate growth and yield projection. A frequently 

used alternative approach to improving precision is 

to inventory stands for up-to-date stocking estimates and then project growth of the sample tree 

lists over a relatively short (relative to forestry 

decisions) time period, say 5 to 15 years. Both approaches have valid applications and are widely 

used, so precept four is that periodic growth estimates from both stand table projection and rotation-length prediction systems must be the same 

when site quality, basal area, and stand age are 

equal. 

MODEL, ELEMENTS 

The standard approach to growth and yield investigation is to establish plots over the range of conditions to be modeled, remeasure the plots over time, 

and mathematically describe the data. As an adjunct to this process, I believe we need to use more 

of what we know in general about stand dynamics 

to creatively expand the range of data we draw 

upon and the way that data are used to fit models. 

One emphasis in this investigation will be on how 

stands behave at biological limits (e.g., at the carrying capacity density and biological rotation age) 

and how selected model constructs function when 

used to describe this behavior. With this strategy, 

modeling can provide understanding and direction 

for further study, rather than only another model 

with a limited scope and capability. 

The model parameters that control behavior will be 

set using a variety of information and fitting 

strategies (from nonlinear estimation to best guesses). Accurately characterizing stand behavior at 

the biological limits will allow greater flexibility in the 

way other information is used to describe model behavior. One cost of such an approach is accepting 

some model bias and the challenge of deciding 

how much can be permitted without damaging 

model performance. 

The plan is to build a two-phase model: (1) an establishment phase (before stand closure) and (2) a 

competition phase describing stand development 

after stand closure, or after some preselected 

young stand age very near stand closure. The establishment phase will be characterized by rapid 

change, the results of which will determine the success or failure of pine establishment. Driving variables in the establishment phase model will include 

the amount, type, and condition of natural regeneration; relative height development of pine to other 

species; and, perhaps, some measure of free-togrow-status of pines (such as percent), type and 

timing of harvest, and preharvest species composition. The primary output from the establishment 

phase model will be an estimate of overstory 

species composition at crown closure (say percent 

basal area by species group). After closure, competition for growing space becomes a major driving 

force in stand development, characterized by selfthinning and reduced rates of change in mean tree 

size, stand volume, and basal area. The two 

phases will be linked via the estimate of overstory 

composition at crown closure. The competition 

phase of the model can also be used for growth 

simulation by not using the establishment phase 

model and simply choosing species composition at 

the linkage age. 

Volume curves will be formed from two basic model 

components: (1) the height models described 

above and (2) expressions of mean size (S) as functions of surviving trees per unit area (N) and stand 

age. Mean size (S) will be bounded above by the 

maximum limiting size (Sm), where 

A limiting size expression like Equation (1 ) will be established for each species group and the value of 

parameters (g) will be adjusted for the proportion of 

the stand each species group occupies. Growth 

curves that express quadratic mean diameter as a 

function of the number of trees in groups will be 

bounded from above by limiting expressions like 

Equation (1) by partitioning the level parameter (g) 

for the total stand model. 

Suwival is a key variable in this modeling effort, but 

relevant data have not been gathered and planned 

permanent plot installation is just beginning. Furt hermore, new observations from planned studies 

will be restricted to periodic mortality in existing 

stands ranging from 10 to 35 years of age. Nonstandard methods of developing survival curves are 

being formulated. One approach will plot mean 

size (quadratic mean diameter or stem volume) 

over number of surviving trees from our initial plot 
measurements (i.e., before repeat measurements 

are available). An approximation for Equation (1 ) 

will be established by choosing the theoretical value 

for the exponent parameter (-3/2 for stem volume 

and - 1 i2 for quadratic diameter) and estimating the 

level parameter (g) either by eye using a graph or 

by fitting a model that describes mean size using 

noniinear estimation (see Lloyd and Harms, 1986). 

In its present form, Lloyd and Harms' model requires the number of trees at the linkage age (approximate stand closure). The strategy here will be 

either to use ocular estimates from graphs based 

on where the observed data point is in relation to 

the limiting size line defined by Equation (1) or to 

modify the model so that only the present number 

of surviving trees is needed. Survival curves will 

then be derived using the fitted stand trajectory 

model and a set of harmonized curves obtained by 

plotting mean size over basal area. Each curve 

comprising the harmonized set represents a different number of surviving trees. 

General knowledge of stand development suggests 

the working hypothesis that height growth can be a 

major driving variable in the growth and yield 

model for pine-hardwood stands. Height growth 

will be incorporated as a driving variable based on 

its relationships with diameter growth, leaf biomass, 

crown volume, relative mean size, competitive 

status, and survival rates. The height information 

will come from stem analyses of key species from a 

range of sites. Separate sets of heightiage curves 

will be developed for each species-group and sitetype combination. 

The stand table projection method will use individual-tree, distance-independent technology like 

that in the STEMS models that are so successfully 

applied to mixed northern hardwood stands. In this 

component of the system, a diameter growth model 

similar to the maximum potential growth and 

modifier approach as presented by Belcher and 

others (1 982) will be used, but the modifier function 

will be designed so that total basal area growth 

from the stand-level model will be distributed according to tree size (diameter) ranking in the tree 

list, thus linking the two model types. Height 

groMh will come from the models for the stand-level 

system described above. Mortality will also come 

from the stand-level model, but the effect of mortality will be imposed by adjusting growth on all 

trees in the list, rather than trying to decide which 

trees to remove (i.e., 'skillis) from the list. The adjustments to growth designed to compensate for mortality will be proportionally greater at the small end 

of the diameter rankings, decreasing to nearly zero 

for the largest trees. 

DATA 

Existing data are limited. However, in a completed 

35-year study of natural loblolly pine regeneration, 

one of the treatments was to follow the natural 

stand that developed after harvesting a mixed pinehardwood overstory. A second treatment in the 

same study produced a mixed pine-hardwood 

stand by killing the large residual hardwoods. This 

study, therefore, is a good starting point even 

though the data are of limited scope and the 

hardwood component was not measured the same 

way as the pine. 

Two new studies are being installed on Piedmont 

sites in South Carolina and Georgia that will be 

used in developing the competition phase model. 

In one study, stem analyses will be used to develop 

the height models mentioned above. The second is 

a large permanent plot growth study in 10- to 35- 

year-old, even-aged, pine-hardwood stands on National Forest lands. About 150 plots will be 

established. Data for the establishment phase of 

the model will come from four regeneration studies 

now in place and others that are planned. Other 

sources of data include areas of pine-hardwood 

regeneration established on a production basis on 

the Sumter National Forest for the last 10 years. 

LITERATURE CITED 

Belcher, David W.; Holdaway, Margaret R.; Brand, 

Gary J. 1982. A description of STEMS the stand 

and tree evaluation and modeling system. Gen. 

Tech. Rep. NC-79. St. Paul, MN: U.S. Department 

of Agriculture, Forest Service, North Central 

Forest Experiment Station. 18 pp. 

Burkhart, Harold E.; Sprinz, Peter T. 1984. A 

model for assessing hardwood competition effects on yields of loblolly pine plantations. 

Publication No. FWS-3-84. Blacksburg, VA: Virginia Polytechnic Institute and State University, 

School of Forestry and Wildlife Resources. 55 pp. 

Jones, Steven M. 1989. Application of landscape 

ecosystem classification in identifying productive 

potential of pine-hardwood stands. [These 

Proceedings.]. 

Lloyd, F. Thomas; Harms, William R. 1986. An individual stand grovvth model for mean plant size 

based on the rule of self-thinning. Annals of 

Botany 57:681-688. 

Smith, W. D.; Hafley, W. L. 1987. Simulating the effect of hardwood encroachment on loblolly pine 

plantations. In: Proceedings of the Fourth Biennial Southern Silvicultural Research Conference. 

1986 November 4-6; Atlanta GA. Gen. Tech. Rep. 

SE-42. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest 

Experiment Station. 598 pp. 
Moderator: 

Gilbert P. Dempsey 

Northeastern Forest Experiment Station 

USDA Forest Service 

PINE-HARDWOOD FO 

MISSlSSIPP1: AN ECC 

PER 

RESTS IN NORTHCENTRAL 

lLOGlCAL AND ECONOMIC 

SPECTIVE 

Bruce 0. Leopold, Garnet. H. Weaver, James D. Cutler, and Randall C. warren' 

. --Overstory and understory characteristics of 19 pine-hardwood forests In north-central 

Mississippi were studied. Stands were naturally regenerated and had not been disturbed. Overstory variables including diameter, basal area, total and merchantable height, species composition, density, radial growth, and site index were studied. Understory variables including relative 

species abundance and whrte-tailed deer summer forage production 

were evaluated in relation to diversity, temporal dynamics, deer carrying capacity, and timber 

production, Stand characteristics varied with topographic position and soil classes. Only pine 

basal area was greatest on upland sites while site index, hardwood basal area, pine and hardwood 

height, and pulpwood production were greatest on bottomland sites. The hardwood component 

was more prevalent in the Interior Flatwoods (IRnl) where hardwood sawtimber and pulpwood yield 

was greatest. Pine dominance decreased with stand age, with a corresponding increase in 

hardwood basal area, yield of sawtimber and pulpwood, and density. Diameter class distributions 

and understory tree composition indicated a shift to a more mixed pine-hardwood overstory as 

stands matured. Summer forage yield was independent of age with an average standing crop of 

96.3 kglha. Pine was the dominant component in all stands sampled. A constant value of hardwood 

sawtimber, more predictable summer forage yield, greater overstory and understory species diversity, increased hard and soft mast production, and greater recreational value when contrasted to 

pine monocultures make natural pine hardwood forests desirable, This is more applicable to 

private, non-industrial landowners with multiple use goals.- 

INTRODUCTION 

The pine-hardwood forest type occupies approximately 20 percent of forested land in Arkansas, Alabama, Texas, and Mississippi. In 

Mississippi, over 11 percent of the state's land mass 

or 22 percent of all forested land is comprised of 

mixed pine-hardwood stands (U.S. Forest Service 

1985). Additionally, over 70 percent of the pinehardwood stands in Mississippi are privately owned 

(U. S. Forest Service 1985) and are not intensively 

managed. This fact is important because for every 

acre of pine (Pinus spp.) plantation in Mississippi 

there are 2 acres of pine-hardwood forest. 

Pine plantation acreage is increasing whereas 

acreage of the pine-hardwood forest type is 

decreasing. This result is due to higher anticipated 

yields from intensively managed pine plantations 

(Miller 1 954). Additionally, regeneration costs are 

often prohibitive to the non-industrial land owner 

(Phillips and Abercrombie 1987)' who simply permits natural regeneration. However, regeneration 

costs are not the sole reason why many private 

landowners choose natural regeneration met hods 

because projected mixed-pine stands meet multiple use objectives (Royer 1 979). Only 30 percent of 

'~ssistant Professor, Department of Wildlife and 

Fisher~es, Mississippi State University, Mississippi 

State, MS; Assistant Dean, School of Forest Resources, Mississippi State University, Mississippi State, 

MS; Environmental Biologist, Breedlove, Dennis and 

Assocrates, Inc, , Florida; Research Associate, Department of Biological Sciences, Mississippi State University, Mississippi State, MS. 

Mississippi's non-industrial forest landowners indicated that timber production has been a major 

goal, although other goals including grazing, 

wildlife, and recreation were also imponant (Poserfield and Moa k 1 977). 

Thus, a majority of forested lands in the Southern 

United States are represented by the pinehardwood forest type and are owned by private, 

non-industrial owners. Most of these stands are 

regenerated naturally because of high cost and multiple use goals as well as owner indifference. Within 

this context, this paper will describe the overstory 

and understory characteristics of naturally 

regenerated pine-hardwood stands found in northcentral Mississippi and relate these characteristics 

to multiple use management goals (timber and 

wildlife management). 

STUDY AREA 

Nineteen pine-hardwood stands (figure I j were 

sampled. Stands were considered for sampling if 

they were naturally regenerated. had not had any 

timber stand or wildlife habitat improvement prior to 

sampling, especially within the last 20 years, and 

were at least 80 contiguous acres. Stands were 

selected to provide a wide range of ages (30 - 100 

years) and thus a wide range of overstory and understory characteristic~ Stands 1-1 1 were sampled 

in 1978-79, stands 12-1 5 in 1974-75, and the remaining stands, 16-1 9 in 1980-81. 
oaks, 2 white oaks, and 4 pine (preferably 2 loblolly, 2 shortleaf) was measured, For pine, radial 

gromh for the previous 5 and 10 years was also 

measured. Site index and basal area were calculated from these data. 

Understory stand measurements. Understory 

vegetation below 4.5 inches dbh was sampled 

using two methods. Species specific frequency and 

occupancy were estimated using 100 foot line transects with 0.10 foot sampling intervals. To estimate 

species specific summer forage yield, ranked-set 

sampling-(Deli and Clutter 1972) was used. Nine, -- - 

Figure 1 .--Location of nineteen naturally 

regenerated pine-hardwood forests sampled between 1974-1 981 in north-central Mississippi. 

Sampled stands were within one of two land 

resource areas (Pettry 1977) and included the IFW 

and the Upper Coastal Plains (UCP). The IFW is underlain with a highly acidic layer of shale with soils 

developed in a silty and clayey material. Soils are 

low in plant nutrients and waterlogged conditions 

are esmmsn during the winter and spring. Topography is mostly flat with little topographic relief. 

Soils of the UCP are derived from loamy, clayey, 

and sandy coastal plain sediments which are 

generally deep, well-drained to moderately welldrained with fragipans and clayey subsoils. Topography ranges from level to steep hill sides that are 

eroded, low in fertility, and acidic. 

The general climate for both regions is very similar 

with annual precipitation ranging from 130 to 150 

cm, concentrated during the winter and spring (McWhorter 1962). Mean annual temperature ranges 

from approximately 17.2 to 18.3' C with winter 

temperatures averaging from 4.4 to 7.2' C and summer temperatures from 27.2 to 28.8' C. 

MATERIALS AND METHODS 

Mured Variables 

Overstory stand measurements. For stands 1-1 5, 

12 one-fifth acre circular plots were sampled to 

determine overstory and understory characteristics. 

But for stands 16-1 9, only 9 one-fifth acre plots were 

sampled in each stand. Growing stock was 

described by measuring all individual trees [ 0.5 in. 

diameter breast high at 4.5 feet (dbh)], total and 

merchantable height ( 4.6 inches dbh; co-dominant 

and dominant trees), age, number of layers in the 

canopy and stand density. Merchantable timber 

was determined either as number of 10 foot bolts 

for pulpwood (dbh 3.6, 3.6 top) or 16 foot bolts for 

sawlogs (hardwood: dbh 11 -6, 9.6 inch top; 

pine:d bh 9.6, 7.6 inch top). Age of at least 2 red 

9.62 foot', circular plots were located 25 feet from 

plot center at 40 degree intervals clockwise from 

North. All plants 4.5 feet in height and less than 

0.55 inches in diameter were clipped. Plants were 

classified as desirable or undesirable deer browse 

(Crawford and others 1969, Mawk 1976, Warren 

1980). Clipped samples were oven-dried at 70' C 

for 72 hours. Individual understory species were 

classified as either grass, forb, vine, or woody. 

Computed Stand Measurements 

Total pine and hardwood basal area were computed using measured tree diameters. Pine and 

hardwood pulpwood (cordslacre) and sawtimber 

(board feet) were computed using a local volume 

table, International 114 inch rule. Diversity of understory vegetation was determined using the Shannon- I 

Wiener Function and standardized as a relative 

index by dividing it by its theoretical maximum (Zar 

1984:32-34). Site index was derived only for loblolly I 

pine (Pinus taeda). 

Simple linear regression analysis was used to assess temporal changes in stand overstory conditions. To determine differences in stand 

characteristics regarding topographic position, nonparametric Mann-Whitney two sample tests for differences in medians were employed. A similar 

analysis with the Mann-Whitney test was applied to 

test for differences in overstory characteristics with 

respect to the land resource areas. 

RESULTS 

Bverstorv Characteristics 

General. Species composition varied with individual stands but 13 oaks ( spp.), 2 pine, 

8 hickories (Car@ spp.), 4 ash (Fraxin~rs spp. f , 3 

elm (Ulmw spp.) and 63 other species were identified. Predominant tree species (comprising 5 percent of any individual stand) included loblolly pine, 
shortleaf pine (P. ~chinata), post oak (a stellata), 

southern red oak (Q., faIca&), white oak (Q. albia), 

water oak (Q. nrgril_j, mockernut hickory (Q. tomenOverstory characteristics varied greatly within 

stands with respect to topographic position as well 

as between stands with respect to land resource 

areas (tables 1 and 2). Pine age ranged from 36 to 

99 years but age of hardwoods ranged between 51 

to 106 years providing a wide range of stand conditions. Dominant and co-dominant hardwoods were 

generally 10-30 years older than pines of similar 

stature, particularly in the young to intermediately 

aged stands (30-60 years old). 

Loblolly pine site index also varied, ranging from 72 

to 98. Pine basal area was highly variable and extended from a minimum of 2 to a maximum of 144 

feet2. Density of hardwoods generally, except for 

stand 12, exceeded that of pine independent of soil 

group or topographic position (bottom vs. upland). 

However, although more dense, hardwood dbh was 

generally significantly lower than pine with only one 

exception (Stand 14), indicating that maturing 

stands consisted of fewer but older pines with an understory comprised primarily of hardwood species. 

Total tree height differed between pine and 

hardwoods, with height of dominant and codominant pine always exceeding that of the 

hardwood overstsry. 

Contrasting mere hantable timber for all stands followed the same pattern as for basal area, tree 

height, and diameter at breast height. Pine sawtimber greatly exceeded that of hardwood, often with a 

20:l ratio. Maximum pine sawtimber measured almost 25,000 board feet contrasted to a maximum 

hardwood sawtim ber of 8,500 board feet. Conversely, hardwood pulpwood, except in stands 11, 16, 

and 17, generally exceeded pine with a 3:1 ratio 

which is understandable since many hardwood 

stems were in the smaller diameter classes. Finally, 

growth of pine varied from 4.2 to 10.7 inches/year. 

Effects of topographic posit ion. Overstory characterist ics differed greatly with respect to topographic 

position. Only average pine density (P = 0.006) was 

greater in plots located on upland sites. Conversely, 

site index (P < .001), hardwood basal area 

Table l.--Umracteristics of 11 natural, pine-hixdwd stands with respect to topographic position (hill and 

bottan) -led in 1978-1986 of the Uppes Coastal Plain lard resuxce area in north-central Mississippi 

Stand Stand #3 Stand #4 Stand #5 Stand #7 SW #8 

Msasurement Bat. Hill Total Bat. Hill Total Bat. Hill Total Bot. Hill Tatal Bat. Hill Total 

Site Index 101.0 87.7 89.8 82.5 70.0 72.1 91.0 79.4 82.3 95.0 79.0 81.7 79.2 72.1 74.7 

- Basal Area 

Pine 67.7 86.6 83.4 56.7 76.8 73.4 68.5 96.9 89.8 83.8 84.4 84.3 42.6 83.5 66.4 

Wardwood 66.6 37.9 42.7 43.2 24.1 27.3 56.4 27.5 34.7 48.7 33.0 35.6 76.3 23.2 45.3 

Diameter 

Pine 

Heicrfit 

Pine 

Gm Inc. 

5 Year 

10 year 

sawtimber 

Pine 

I.ia&md 
Table 1.- istics of 11 na stands with pitian 

(kJI and 78-1986 of thae land ~scrurrr? 

asis1mi 

Stard till Stand #16 Stard #17 

Bat. Hill Bat. Hill Bot. Hill mtaf Bot. Will 

istics of 8 mturdh, pine-- stands with respect to topgraphic position (hill and 

1978-1986 of the Interior Flatwoads land resauree area in mrth-central Mississippi 

stand #2 Stand #6 Stand #10 

Bot. Hill Total Bat. Hill Totab l&ot. Hill Tatdl 
(P = 0.006). pine diameter (P = 0.002). pine 

(P = 0.004) and hardwood (P = 0.01 3) height. and 

hardwood pulpwood production (P = 0.003) were 

greatest on bortomland sites. Sawtimber production 

and pine basal area varied greatly among stands 

and site but were independent of topographic position. Hardwood diameter was equal (P - 0.32) for 

topographic positions because most hardwood 

stems were less than 3.6 inches dbh. 

Effects of soil regime. Many overstory characteristics differed greatly with respect to land resource 

area. Pine basal area (P = 0.0031, pine density 

(P = 0.004). hardwood density (P = 0.05). and pine 

sawtimber (P = 0.05) were greater for the UCP when 

contrasted to the IFW. Conversely, hardwood basal 

area (P =0.019). hardwood diameter (P =0.001), 

average hardwood height (P - 0.01 1 ), hardwood 

sawtimber (P = 0.001), and hardwood pulpwood 

production (P =0.001) were greater for the IFW. 

Variables that were not significantly different between the two land resource areas included site 

index, pine diameter, pine height, and radial growth 

(mmiyear) . 

Plnr Hardwood 

1 2 4 8 8 l0 12 14 16 18 20 22 24 26 28 30 

A. Diameter Class 

..... 1 2 4 8 8 10 12 14 18 18 20 22 24 26 28 30 

C. Diameter Class 

Diameter class (age) distribution. Pine and 

hardwood diameter class distributions were 

deveioped for stands 1-1 I and 16-1 9. Diameter 

class 7 represented number of stems 3.55 inches 

dbh, whereas all subsequent diameter classes represent 2 inch diameter increments. 

Generally, a consistent pattern was found where 

pine diameter distribution formed a 8'beil-shay>ed 

curve or was slightly skewed to the left. Differences 

did exist and were primarily in location of the mode, 

increasing as age increased (figures 2 and 3). 

Hardwood diameter distributions were significant1 y 

different from pine, with most individuals in the 

smaller diameter classes which supports earlier observations regarding hardwood diameter relationships. Additionally, the modal diameter for 

hardwoods did not shift significantly when contrasted to pine (figures 2 and 3) 

Figure 2.--Diameter class distributions for natural! y 

regenerated pine-hardwood forests sampled between 19'74-1981 in the Upper Coastal Plain land 

resource area of nort h-central Mississippi. 

A = Stand 11 ; B = Stand 8; G = Stand 4; D = Stand 19. 

...... f 2 4 6 8 $0 12 14 16 18 20 22 24 26 28 30 

8. Diameter Class 

3 2 4 8 8 10 12 14 18 18 20 22 24 28 28 30 

D. Diameter Glass 

215 
1 2 4 8 8 K) 12 14 18 18 20 22 24 26 28 30 

A. Diameter Class 

1 2 4 8 8 10 12 14 18 18 20 22 24 26 2B 30 

C. Diameter Class 

Figure 3.--Diameter class distributions for naturally 

regenerated pine- hardwood forests sampled between 1974-1 981 in the Interior Fiatwoods land 

resource area of north-central Mississippi. 

A = Stand 10; B =Stand 1 ; C =Stand 2; D = Stand 6. 

Temporal overstory dynamics. Simple linear 

regression analyses were performed to assess changes in overstory parameters with respect to age 

(table 3). Age was positively related to hardwood 

basal area (P = 0.001 ), average pine (P - 0.001 ) and 

hardwood (P = 0.009) diameter, hardwood sawtimber (P = 0.004) and hardwood pulpwood (P = 0.007) 

production. Pine basal area (P =. 0.002), pine density (P =0.001), pine growth (mmiyr) (Fa =0.004), 

percentage pine savdtimber production (P == 0.026), 

and pine pulpwood volume (P = 0.002) were inversely related to stand age. 

Stand age was regressed with total sawlimber for 

red oak, white oak, and other hardwoods. Only red 

oak sawtimber significantly increased with age 

(P = 0.0295). 

1 2 4 8 8 HI I2 14 18 18 20 22 24 2% 28 30 

8. Diameter Class 

1 2 4 8 8 10 12 14 18 18 20 22 24 26 28 30 

D. Diameter Class 

Regressions were performed relating stand age with 

total basal area of hard, soft, and total mast producing trees. Hard mast producers included oaks and 

hickories but soft mast producers included flowering dogwood, blackgum, huckleberries r\/accinium 

spp.), haurthorn (Crataeaus spp.) and grape (Vitus 

spp.). Basal area of soft, hard, and total mast 

producing trees remained relatively constant with 

respect to stand age (slope not significantly different from 0.0, P > 0.05). 

Species diversity and richness. Relative frequency 

of understory species was derived from the fine transect data. A total of 261 was identified from line transects. This total included 25 grasses, 104 forbs, 23 

vines, 28 shrubs. 52 trees, 7 ferns, 12 sedges, 9 

brysphtes, 1 mushroom, and 1 livewort. Species 

occurring most frequently (percentage occurrence 

exceeding 2.5 percent) included southern red oak, 

poison ivy (Rhus radicans), greenbriar (Smilax 

, grape @. j, sweetgum, flowering dogwood, and red maple. Most species were 

tree species. 
T- 3. - Selected correlation mf ficients (rf 

relating age (pine) and 

stanl characteristics for natural p 

fed in 1978-1985 in north- central Mississippi 

Pb G (10 YS) -0.662 0.004 -0,316 

Foxb 

Tatal Desirable 

Relative species diversity (grass, forb, vine, shrub, 

tree) ranged from 0.35 to 0.85 and was independent of stand age (P > 0.05). Species richness 

(total number of species within each life form) of the 

overstory varied from as many as 58 species to as 

few as 21. Similar to diversity, understory species 

richness was independent of stand age. For example, for stand 9 (age 99), species richness was 

44 contrasted to stand 16 (age 37) with a species 

richness of 50. Similarly, species richness of the understory was aiso independent of stand age, ranging from 78 to 130 species. 

Deer Summer Forage Yield 

Total yield was extremely variable ranging from 38.0 

to 198.0 kgiha, with an average of 97.2 kgiha (table 

4 and 5). Grass production ranged From 0.40 to 

35.3 kgiha with an average of 11.6 kgiha. An 

average forb forage production of 15.1 kgiha, ranging from 1.3 to 58.7. Production of vine browse was 

similar to forb, ranging from 4.5 to 79.2 and averaging 30.5. Woody browse production was greatest, 

averaging 40 kgiha and ranging between 10.9 to 

120.2 kgjha, 

in north-central Mississippi 

ite 

searhi 4 

Botm 

Hill 

ite 

stanJ.5 

rnb 

Hill 

ite 

S 

ite 

mtam 

Hill 

ite 

S 

Hill 

ite 

ite 

Stand 19 

Bottm 

Hill 

ite 

Contrasting total deer summer forage yield (dry 

weight kg/ha) with respect to topographic position 

indicated no significant differences (P = 0.836). 

Similarly, total deer forage yield was not significantly diMerent with respect to land resource area 

(P = 0.231). Finally, regressing stand age with deer 

forage yield indicated that forage yield was independent of stand age (P > 0.05) (table 3). 

Po estimate an approximate number of deer that 

the pine-hardwood forests may sustain, several assumptions must be made. Jacobson (1984) found 

that a deer consumed an average of 1 306 kglday, 

dry weight basis. Additionally, if we assume that to 
TAl3.E 5. --Deer forage yield (kg/haj for mturdl pine-- 

forests sai?~,led in 1978-1985 of the Interior Flatwoods lard 

IESXKE area in north-central Mississi~pi 

Li fe form 

Stand Grass Forb Vine WacdV Total 

sm 1 

&IttQn 21.4 40.6 47.9 20.8 130.7 

Hill 11.6 64.2 30.1 40.7 146.6 

14.9 56.4 36.0 34.1 141.4 

stand 2 

Eottam 7.2 4.4 32.3 15.1 59.0 

Hill 0.8 2.7 20.1 10.0 33.6 

Ccmpsite 1.9 3.0 22.2 10.9 38.0 

Stand 6 

Both 2.0 8.7 30.0 43.0 83.7 

Hill 1.4 0.9 31.5 74.0 107.8 

Cmpsite 1.6 3.5 31.0 63.7 99.8 

Stand 13 

Canposite 16.6 14.4 33.4 16.3 80.7 

maintain plant vigor, only 50 percent of available 

yield may be consumed and assuming a 92 day 

period (summer), the following formula may be 

used: 

Y = 0.50 x foraae production (kalha) x 1 

1.306 kgtdeertday 92 days 

where Y = number of deerihectare. 

This yields a range in summer deer carrying 

capacities of 0.158 - 0.824 deerjhectare, with an 

average of 0.401 deerlhectare or a stocking density 

of 1 deeri2.5 hectares. 

Overstory Reproduction. We compared percentage occurrence of major overstory species (identified on 1/5 acre ploti) and percentage occurrence 

of understory species (line transect data). Tree 

species examined included loblofly and shortleaf 

pine, white oaks, red oaks, sweetgum, hickories, 

ash, red maple, blackgum, magnolias (Magnolia 

spp.), elms, black cherry (Prunus serotina), eastern 

red cedar, persimmon (Diospvrus virginianus), and 

beech (m grandifolia). 

occur, sweetgum occurrence in the understory was 

equal to or less than occurrence in the overstory. 

Red oaks were always more predominant in the understory whereas white oak was more predominate 

in the overstory in two stands, equal in four stands, 

and more abundant in the understory for the 

remaining five stands, 

DISCUSSION 

Naturally regenerated pine-hardwood forests 

sampled in north-central Mississippi were extremely 

complex regarding plant species diversity, overstoryiunderstory species composition, composition 

changes with respect to time, yield of deer forage, 

and timber production. Additionally, within stands, 

site differences (upland vs. bottom) and the effects 

of soil were also evident. 

Several past studies demonstrated that intensively 

managed pine plantations produce a large amount 

of deer browse when compared to forest stands not 

intensely managed (Schuster 1 967, Halls 1 970, Blair 

and Enghardt 1976, Hurst and Warren 1980, Cutler 

1986). However, biomass of browse may not be 

completely sufficient if diversity of the understory is 

also desired. Intensive forest management generally 

results in apparent loss of spatial, temporal, and vertical ecosystem diversity which is considered essential for a variety sf wildlife, esthetics, and ecosystem 

stability (White 1975). Relative stand diversity of the 

overstory ranged from 0.244 to 0.781 which would 

not be the case for intensively managed monocultures. Concerning the understory, relative diversity 

of four, 10 year old bedded and four, 8 year old tree 

injected pine plantations was 0.603 and 0.614 

respectively (Warren, unpublished data) which is approximately equal to species diversity computed 

for our stands. Additionally, only 43 species were 

identified on the line transects for both bedded and 

tree-injected plantations. Finally, unmanaged pine 

plantations older than 11 years provide little deer 

forage yield (Cutler 1980) whereas deer forage yield 

for the natural pine-hardwood forest, although significantly lower than in pine plantations, remained 

constant and therefore predictable, over all age classes (P > 0.05). 

Another component of the pine-hardwood forest is 

mast production. Several wildlife species are noted 

for their use, if not need, of hard and soft mast to 

ensure winter survival and possibly optimal productivity the following spring. White-tailed deer 

(Segelquist and Green 1968) and wild turkey 

(Gardner and Arner 1968, Billingsley and Arner 

1970, Beasom and Pattee 1980) are two such 

Generally pine dominated the overstory but was species. We computed total basal area for hard and 

scarce to absent in the understory (figures 4 and 5). soft mast producers and found that total basal area 

However, as expected! percentage occurrence of for hard mast producers ranged from 0.9 to 64.1 

hardwoods was greatest within the understory con- feet2 and 0.6 to 13.9 feet2 for soft mast producers. 

trasted to overstory abundance. One exception did 
Overbtory Understory = Overbtory Understory 

PWRSHARBTMECCPB 

lhewlselualh 

nldechdal c': et ek cljfm:a8c eOto Mkpo rrlh 

agr as I Y rn Okuy pup1 m 

a m lmoa o 

e P n 

PWRSHARBTMECCPB 

ihewiaelualheee 

nldechdalgmedre 

et ek cln rasc eOto Mkpo rrlh 

agr Okuy ::Pi rn a m Imoa k e P n 

Species or Species Group Species or Species Group 

I = Overetory Understory 

Overstory Underaiory 

PW.RSHARBTMEC 

lhewlaelualh 

nldechdalgme 

e t e k cln r eOto Mkpo r afar ag I Y Okuy puPi a m lmoa k SP 

Species or Species Group 

C P B e e e d r e a r c rih m 

rn 

0 

n 

PWRSHARBTMECCPB 

lhewlsetualheee 

nldechdalgmedre 

et ek cin raac eOto Mkpo rrih 

agr ag I Y m Okuy puPl m a rn lmoa o 

C. Species or Species Group 

Figure 4.--Percentage occurrence of selected tree 

species within the overstory and understory for 

naturally regenerated pine-hardwood forests 

sampled between 1974-1 981 in the Upper Coastal 

Plain land resource area of north-central Mississippi. A = Stand 4; B = Stand 9; C =Stand 8; D = Stand 

11. 

the IFW sites, on average, are of a higher productive potential and thus able to maintain hardwoods 

into dominate and co-dominant positions in the 

stand. This fact becomes important when sawtimber value is considered. 

Changes in sawtimber value with time are obsewable when the 1978 inventory is priced at 1978 and 

1989 stumpage prices as reported by Timber Mart 

South. Recent increases in hardwood sawtimber 

prices do make an impact on value distribution 

(table 6). In this case, although it may seem that 

When mast production is added to deer forage 

yield, the value of pine-hardwood forests for forage 

increases and possibly exceeds that of older ( 5 

year old) pine plantations (Hurst and Warren 1980). 

Average total stand sawtimber volume differed 

slightly from the UCP to the IFW, 1 1.5 MBF and 

10.1 MBF respectively. However, the UCP stands 

were significantly different when species composition of sawtimber is compared with IFW stands. 

The UCP stands were 95 percent pine and 8 percent hardwood by volume while the IFW stands 

were only 65 percent pine and 37 percent 

hardwood by volume. Since all study stands were 

chosen on the basis of a non-disturbance criterion, 

the very real influence of site condition on species 

composition was observable. The UCP sites are 

usually defined as pine management sites, whereas 

Table 6.--Volume anl value distribution by site ( 

Plain an3 Interior Fla pp:) and prlce reporting 

years for natural pine in mrth-central 

Kississisi. 

Year 1978 1989 

LandRescrurceArea % Volume % Value % Value 

~pper Cnastal Plain 

Pine 

Harfmxd 

Interior Flatwoods 

Pine 

Halxbxd 
pine sawtimber dominates the pine-hardwood 

stands, the increase in value per unit of timber is 

greater for hardwoods and thus decreases the margin of difference between pine and hardwood. 

A more critical management issue is the amount of 

value grovvth required to carry either group of 

stands for another growing season. If a 10 percent 

alternate rate of return is required, then a decision 

variable may be identified for each stand. For the 

UCP pine stands, annual volume growth must be 

0.5 MBF/acre if stumpage prices of $20O/MBF are 

assumed. Not many of these stands will reach this 

level of growh under conditions as described. Essentially, the same holds true for the IFW stands. 

Since these stands have a higher proportion of 

hardwood, growth would likely be lower. But the 

lower volume grovvth may be offset by higher values 

associated with selected hardwood species. This 

m Ovsrrtory Undsrrtory 

PWR 

the 

nld 

et s 0 

a. O k a 

k 

SHARBTMECCPB 

wlaefualheee 

echdalgmedre 

e k cin raac rv? rrlh Q r uy PUP1 Ym 

rn lmos 0 

8 P n 

Species or Species Group 

0.36 - I 

= Ovsrrtory Undsrrtory 

PWRSHARBTMECCPB 

lhewlaelualheee 

nidechdalgrnedre 

et ak I n raac eoco ~ipo rrih IYm o:rt; ;rt,, m 8 m tmoa o k eP n 

C. Species or Species Group 

Figure 5.--Percentage occurrence of selected tree 

species within the overstory and understory for 

naturally regenerated pine-hardwood forests 

sampled between 1974-1 981 in the Interior Flatwould result in managers being more likely to 

reduce the pine component volume and value on 

both site groups. A normal scenario would be to 

begin cutting pine volume when the larger sized 

trees were saleable for small sawlogs. This diameter 

limit cut is frequently applied to unmanaged stands 

in the South. The end result is to convert the stand 

from a pine-hardwood type to a mixed species type 

where pine is a minor species. Uninformed 

managers frequently make timber sale decisions 

which drastically and negatively impact on future 

revenue flows from the timber resource. 

This study supports the concept of managing pinehardwood stands to optimize pine timber production as an effective deer management treatment. 

There is no significant difference between deer 

forage yield between the stands or land resource 

PWRSH 

Ihewl 

nldee 

et ek eOto aar Okuy 

a m 

Ovsrrtory tE4 Understory 

TMECCPB 

ualheee 

itmedre ratc Po rrlh 

Pi mm o a Q 

P n 

Species or Species Group 

m dverrt0ry Underrtory 

PWRSHARBTMECCPB 

ihewlrelualheee 

nldechdalgmedre 

et ek cin rare 

eOtO .Qr FkP0 rrlh 

Okuy pip! a m fmoa m k e P n 

Species or Species Group 

woods land resource area of nort h-cent ral M ississippi. A = Stand 10; B = Stand 1 ; C = Stand 2; 

D = Stand 6. 
area. Yet, there is a significant difference in average 

volume of pine sawtimber on the UCP (10.6 

MEfFlacre) and the IFW (6.4 MBF/acre). 

Landowners must integrate species and site 

capability in choosing a management system. In 

many instances, Mississippi forest sites are much 

better suited for pine production. However, pinehardwood forests offer more than timber production 

values. Revenuelacre for hunting leases are growing. An annual hunting lease which pays $10/acre 

would return income equivalent to the value of 50 

board feet of pine sawtimber growthfacre when this 

growth is valued at $200/MBF. If pine sawtimber 

growth potential is reduced by 100 board 

feetlacrelyear, then the annual hunting lease 

returns should equal $2O/acre. Additionally, pinehardwood forests offer additional values not readily 

available in intensively managed pine plantations including bird-watching, hi king, watershed values, 

fishing, and a greater diversity of hunting opportunities (squirrels, turkey, white-tailed deer). Therefore, forest management must be tempered to meet 

multiple use goals and within the pine-hardwood 

forest type, reduced timber yields may be acceptable when other values are desired, particularly by 

the non-industrial, private landowner. 

LITERATURE CITED 

Beasom, S. L.; and 0. H. Pattee. 1980. The effect of 

selected climatic variables on wild turkey productivity. Proceedings National Wild Turkey 

Symposium 4:127-135. 

Billingsley, B.B. Jr. and D. H. Arner. 1970. The nutritive value and digestibility of some winter foods of 

the eastern wild turkey. Journai of Wildlife 

Management. 34: 176-1 82. 

Blair, R. M.; and H. G. Enghardt. 1976. Deer forage 

and overstory dynamics in a loblolly pine plantation. Journal Range Management 29:104-108. 

Crawford, H. S., J. B. Whelan, R. F. Harlow, and J. 

E. Skeen. 1975. Deer range potential in selective 

and clearcut oak-pine stands in southwestern Virginia. Southeastern Forest Experiment Station, 

Asheville, North Carolina. U.S. Department of 

Agriculture Forest Sewice Research Paper SE134. 12 pp. 

Cutler, J. D. 1986. Stand, site, and white-tailed deer 

food conditions in pine plantations and pinehardwood forests in north-central Mississippi. 

M .S. Thesis, Mississippi State University, Mississippi State, MS. 80 pp. 

Deii, Ts R.; and J. L. Cluner. 1972. Ranked-set sampling theory with order statistics backgroutid. 

Biometries 28:545-555. 

Gardner, D.T. and D.H. Arner. 1968. Food supplements and wild turkey reproduction. Transactions 

North American Wildlife Conference 33:250-258. 

Halls, L. K. 1970. Growing deer food amidst 

southern timber. Journal Range Management 

23:213-215. 

Hurst, G. A.; and R. C. Warren. 1980. Intensive pine 

plantation management and white-tailed deer 

habitat. pp. 90-102. In: R. H. Chabreck and 

Robert H. Mills. eds. Integrating timber and 

wildlife management in southern forests. Twentyninth Annual Forestry Symposium. Louisiana 

State University, Baton Rouge, Louisiana, pp. 1 19. 

Mawk, J. D. 1976. Food habits of white-tailed deer 

and proximate analysis of some important deer 

food plants in east-central Mississippi, M.S. 

Thesis, Mississippi State University, Mississippi 

State, Mississippi. 36 pp. 

McWhorter, J, C. 1962. Climate paMerns sf Mississippi. Mississippi Agricultural and Forest 

Experiment Station Bulletin Number 650, Mississippi State University, Mississippi State, MS. 

Miller, W. B. 1954. Pine or Hardwoods"! comparison of grov\neh rates of loblolly and Virginia 

pines and upland hardwoods in the Piedmont of 

Noflh Carolina. Southern Lumberman 88:32-34. 
Pettry, D. E. 1977. Soil resource areas of Mississippi. Miscellaneous Information Sheet 1278. 

Mississippi Agricultural and Forest Experiment 

Station, Mississippi State University, Mississippi 

State, MS. 2 pp. 

Phillips, D. R. and J. R. Abercrombie. 1987. Pinehardwood mixtures - a new concept in 

regenerat ion. Southern Journal Applied Forestry 

11 1192-197. 

Porterfield, R. L. and J. E, Moak. 1977. Timber 

management for non-industrial forest owners. 

Southern Journal of Applied Forestry 1 :2-6. 

Royer, J. 1979. Conclusions from a review of 50 

years of small woodlot owner studies. Paper 

presented at Southern Forest Economics 

Workshop. Duke University, Durham, NC. 

Schuster, J, L. 1967. The relation of understory 

vegetation to cutting treatment and habitat factors in an east Texas pine-hardwood type. 

Southern Naturalist 1 2:339-364. 

United States Forest Service. 1985. The South's 

Fourth Forest: Alternatives for the Future. U.S. 

Department of Agriculture. Forest Service. Forest 

Resource Report No. 24. 512 pp. 

Warren, R. 6. 1980. Food abundance, plant rating, 

and track counts'for white-tailed deer; effects of 

control burning pine plantations; avian populations in pine plantations site prepared by 

mist-blowing and tree-injection; and acorn 

production and squirrel population estimates in 

the mixed pine-hardwood forest type of eastcentral Mississippi. M. S. Thesis, Mississippi State 

University, Mississippi State, MS. 830 pp. 

White, L. D. 1975. Intensive forest management effects on understory plant production. Pages 

138-1 52 h W. L. Pritchett and D. R. Crowe eds. 

Forest Soils of the southeastern coastal plains. 

University Florida Sshool Forest Resources. Consenration Resources Report 2. Gainesville, FL. 

Zar, J. W, 1984. Biostatistical Analysis. 2nd. Ed. 

Prentics-Wall Inc. Englewosd Cliffs, NJ. 718 pp. 

Segelquist, 6. A. and W. E. Green. 1968. Deer food 

yields in four Ozark forest types. Journal Wildlife 

Management 32:330-337. 
PINE AND HAR D REGENEMTION OPTIONS ON A 

CUMBERLAND PMTEAU SITE: AN ECONOMIC 

PERSPECTIVE 

Todd E. ~e~~' 

.-In a study conducted by the U.S. Forest Service near Sewanee, IN, 11 year psrisrmance data were available on several low cost regeneration options implemented following the 

shear harvest of an upland mixed hardwood stand. We evaluated the options to afiow natural 

development, to plant loblolly pine, and to plant loblolly pine following herbicide injection treatments of residual hardwoods, The YlELDplus and HDWD s~Nvvare packages were used to project 

existing stand conditions forward to rotation age. Cost data and stumpage market assumptions 

were used to simulate the financial profitability for a full rotation cycle of each regeneration option. Results should be relevant to the owners of moderate quafiw upland sites in the South dssiring to generate some forestry income with minimum capital investment. 

INTRODUCTION 

The Cumbedand Plateau area of Tennessee 

abounds with low-quality hardwood trees (i.e., poor 

form, relatively small, low value sawtimber species). 

The primary reason for this condition is past logging practices, which over many years removed the 

higher grade growing stock. Other reasons behind 

the profusion of low-quality hardwood stands include the moderately low site quality typical for this 

region, fire and weather related damage, and insect 

and disease problems (McGee 1982). Non-industrial private landowners control forest management activities on the bulk of these lands. The long 

established pattern of irregular harvests which "take 

the best and leave the rest" continues today as dictated by personal financial need. Although pine 

plantations earn a respectable return on investment, conversion costs form a barrier which few 

landowners are willing or able to overcome. Costs 

for conversion can be reduced considerably if first, 

a mixture of pine and hardwood is considered acceptable, and second, markets for low-quality 

hardwoods develop to the point that intensive (i.e., 

mult i-product , mixed species) harvesting becomes 

economically feasible. Ironically, the prospect of 

rising hardwood stumpage prices, relative to pine, 

also raises the possibility that intentional development of a pine component is not warranted. 

Markets for low value hardwood trees are evolving, 

thus sparking new hope for better management of 

the region's low-quality hardwood stands. Domestic paper manufacturers increasingiy are substituting hardwood for pine when expanding mill 

capacity (Skog and others 1988). The export 

market for hardwood chips is also growing. Current trends indicate that intensive hawest of Cumbedand Plateau hardwoods may become 

economically feasible within a decade. Intensive 

harvesting of low-qua1 ity hardwood stands effectively clears the site of trees and creates a number of 

options for regenerating new stands. The purpose 

of this paper is to project the growth, yield, and 

economic performance of 3 possible low-cost 

regeneration options following a shear hawest 

which removes all material down to a 4" diameter 

breast high (d bh) limit. The regeneration options 

are: 

1 ) allow natural development 

2) plant loblolly pine 

3) inject residua6 hardwoods with herbicide and 

plant pine 

We use simulation results to speculate on which 

regeneration option is the most financially artractive. We also contrast financial returns for these 3 

low cost regeneration options with those for a 

fouflh, an intensively site prepared pine plantation. 

CUMBERLAND PUtTEAU STUDY 

The 40 acre study area is located on the University 

of the South Domain near Sewanee, "Tnnessee 

(figure 1) and is typical of Cumberland Plateau land 

which has been logged and burned at irregular intervals (MeGee 1 980; McGee 1 986). Prior to a 

shear harvest, the area was fully stocked with lowquality hardwood trees. Oak site index averaged 

68-65 feet (base 50). Afier harvest, the area was 

divided into 1 acre plots. Six plots were planted to 

lobloll y pine on an 8 x 10 spacing (545 stemslacre). 

"Tree sf these 6 plots received herbicide injection 

treatments for residual trees greater than 4 1 /2 feet 

tall followed by re-treatment within the year of trees 

which escaped injection on the first pass. Three additional plots sewed as controls. mihe remaining 

plots received other treatments which are not 

relevant to this discussion. 

l~~stems Analyst, Tennessee Valley Authority, Norris, 

TN. 
Cu~herland Plateau I +- 

Study Site 

Figure 1 .- 

~FL \ 

\\\ 

i 

-Location of Cumberland Plateau study area. B' 

Eleven year growth and yield performance data Cultural Practice Costs 

were c6llected and summarized for the 9 plots used 

for this paper. McGee (1 989) provides a full accounting of these results. The plot data summary 

(table 1 ) show that herbicide injection treatments 

boast the height growth, suwival, and basal area 

development of the planted pine. Data for regeneration options number 2 and 3 refer to the pine component only. Spatially, the pine component has 

evolved into clumps throughout the plots where 

pine was planted. Visual inspection of the plots 

reveals planting rows where nearly every pine tree 

has survived alternating with areas where no pine 

trees are visible. 

Table 1.--Average performance values per acre by regeneration 

option measured 11 years following treatment (McGee 1989) 

Regeneration Site Number Basal 

Option Index Stems Area 

1) Natural 65 (base 50) oak 666 - - 

2) Plant pine 53 (bese 25) loblolly 0 32 ft2 

3) Inject residuals, 57 (base 25) Poblolly 458 65 ft2 

plant pine 

ASSUMPTIONS 

Various assumptions must be made in order to 

seed the growth and economic projection models. 

They are grouped into categories for cultural practice costs, stumpage prices, and growth and yield 

simulation procedures. 

Cultural practice costs were incurred on the study 

site for herbicide injection treatments and for hand 

planting of pine. An intensively site prepared plantation would entail costs for chopping, burning, and 

machine planting. Although an intensively site 

prepared pine plantation was not established on the 

study site, the estimated costs and returns are considered here for comparison purposes (regeneration option number 4). Southwide average costs 

were selected for all treatments so that the simulation results would be more generally applicable 

(table 2). Table 3 summarizes the cultural practice 

costs assumed for each of the four regeneration options. 

Table 2.--Southwide average cultural practice costs (Straka, 

Watson, and Dubois 1989) 

Cultural Practice Cost (dollars/acre) 

Herbicide Injection 11 8 

Site preparation 

Hand Planting 

Cutover land following less 

than intensive site preparation 

Machine Planting 

Cutover land following 

intensive site preparation 

Loblolly Pine Seedlings (545/acre) 

Tennessee Division of Forestry 

Double Chop 113 

Burn Chopped Areas 

Ground drip torch 
Table 3.--Total cultural practice costs by regeneratio~i option 

Regeneration Option Cultural Practices Cost (dollars/acre) 

If Natural None 0 

2) Plant pine Hand planting, loblolly 5 3 

pine seedlings 

3) Inject residuals Herbicide injection, 101 

plant pine hand planting, loblolly 

pine seedlings 

4) Chop, bum, and Double chop. burn 171 

plant pine chopped area, machine 

plant, loblolly pine 

seedlings 

Prices for Tennessee pine and hardwood timber 

fluctuate widely according to location and quality. 

The average prices reported in table 4 show that 

oak sawtimber stumpage values have been rising 

briskly in recent years (Neal and Norris 1989). 

Mixed hardwood sawtim ber values average less 

than those for pure oak. When we questioned 

several foresters operating in the Cumberland 

Plateau region of Tennessee, they indicated that the 

hardwood pulpwood market had not emerged yet 

in their vicinity. They also mentioned that "Plateau 

oak" sawtimber stumpage values run considerably 

less than those reported in table 4. Pine pulpwood 

prices currently range from $1 2lcord or more in the 

southern portion of the State where paper mills are 

in close proximity, to virtually no value in the northern portions of the State. Since future prices are impossible to predict, we used the 1977-1 987 average 

prices as a starting point for the simulation analysis. 

Table 4.--Stumpage prices per cord and per Mbf (thousand board 

feet) for Tennessee (Neal and Norris 1989) 

Southern Pine Oak Year Cord Mbf (Scribner) Cord Mbf (Doyle) 

Average 6.57 68.27 2.09 90.36 

Stand dynamics for pine and hardwood mixtures 

are not well understood. Fortunately, the 11 year 

performance data establish trends which afford 

some indication of future stand development. 

However, bold assumptions about future stand 

growth must be made before a model is used to perform a projection. The YIELDplus: Timber Yield 

Forecasting and Planning Tooi (Hepp 19987) and 

HDWD (Burkhart and Sprinz 1984) computer 

programs were selected for performing growth 

projections and financial analyses. YIELDplus 

relies on a variety of published growth and yield 

models for single species, evenaged stand types. 

The HDWD model is designed to estimate future 

volumes in loblolly pine plantations which have a 

significant hardwood component. In HDWD, the 

user must specify the percent or amount of basal 

area in hardwood in the main canopy. This percent 

is then assumed to remain constant. 

The pine-hardwood mixtures examined in this study 

required some innovative applications of the 

models. Initially, the YlELDplus cutover site loblolly 

pine plantation simulator was selected for projecting development of the chop, burn and plant pine 

regeneration option. However, yields estimated 

from the simulator compared with the I1 -year data 

for the inject residuals, plant pine regeneration option revealed an inconsistency. Apparently, the 

mediocre site quality of the Plateau region results in 

significantly less hardwood competition than is typical for the South, given equal levels of site preparation intensity. Therefore, the YlE LDpIus sldfield 

loblolly pine simulator was judged more appropriate to simulate the chop, burn and plant pine 

option. This simulator enjoys the added benefit of 

being based upon data collected from lobloliy pine 

plantations located in the region (Smalley and 

Bailey 1974). Table 5 summarizes the model 

selected and other considerations made for simulating the growth and yield performance of each 

regenerat ion option. 

Table 5.--Assumptions for projecting growth and yield by 

regeneration option 

Regeneration Model I 

Calibration 

Option Assumptions 

1) Natural YIELDplus =~ge 29 basal area 

(Upland oak) 87 ft /acre, 782 

stems/acre 

2) Plant pine HDWD 

3) Inject residuals, HDWD 

plant pine 

Hardwood is 40 percent 

of total basal area 

Hardwood is 13 percent 

of total basal area 

4) Chop, burn, and YIELDplus (Oldfield Piant 545 sterns: acre, 

plant pine loblolly pine) site index ??{base 25) 

%ased on full stocking level for 666 stems at age 11 (Gingrich 

1964) and projecting forward 9 years using the YlELDplus upland 

oak simulator (Dale 1972). 

All financial analyses were conducted using 

YIELDplus. Valuation of the hardwood component 

in pine-hardwood miaures posed a challenge. For 

lack of a better approach, the assumption inherent 

to HDWD that the proportion of hardwood basal 
area remains constant over time following crown 

closure, was expanded to include volume. The Soil 

Expectation Value (SEV) (Faustmann 1849) was 

used as the financial criterion for relative comparison of financial returns. SEV is expressed in 

real, after tax, dollars using a 4 percent, before tax, 

discount rate and a 28 percent income tax rate. Applicable reforestation income tax incentives were 

used to adjust cash flows prior to SEV calculations. 

The average stumpage prices cited in table 4 were 

used to translate sawtimber and pulpwood volume 

estimates into value estimates. 

SlMULATlON RESULTS 

The YlELDplus and HDWD models were used to 

determine the SEV's for each regeneration option 

across a range of rotation ages. Thinnings were not 

considered in the projections to avoid excessive 

complexity. The inject residuals, plant pine 

regeneration option showed the highest simulated 

SEV (figure 2), followed closely by the chop, burn 

and plant pine option. By comparison, both the 

natural and plant pine regeneration options performed poorly despite their no or low investment 

costs. The after tax internal rate of return for the inject residuals, plant pine regeneration option was 

5.1 percent using a 40 year rotation age. However, 

the chop, burn, and plant pine option performed 

nearly as well for the assumed stumpage price 

levels. When risk of failure for the pine to survive is 

accounted for, the chop, burn, and plant pine option appears to be the overall best. 

The rotation age which maximized SEV for each 

regeneration option was used for subsequent 

analyses. The regeneration options and the respective rotation ages are: 

1 ) natural, age 80 

2) plant pine, age 45 

3) inject residuals, plant pine, age 40 

4) chop, burn, and plant pine, age 45. 

Undoubtedly, thinning regimes would change the 

rotation ages, particularly if the pine and hardwood 

components were treated separately. Figure 3 illustrates the mixture of simulated pine and 

hardwood sawtim ber production for each regeneration option. The volumes reported reflect differences in log rules and rotation ages. 

Future stumpage prices cannot be predicted with 

certainty. Real appreciation rates in sawtimber 

stumpage values for pine versus hardwood are subject to speculation. Figure 4 shows how SEV varies 

across a range of hardwood sawtimber stumpage 

values, while holding the value of pine sawtimber 

constant at $68.27lMbf (Scribner). Conversely, 

figure 5 shows how SEV varies by changing pine 

sawtimber stumpage values when hardwood sawtimber values are held constant at $90.36iMbf 

(Doyle). 

Figure 4 indicates that increasing hardwood sawtimber stumpage prices do not compensate well for the 

slow growth rate of hardwood relative to pine. 

Figure 5 implies that if pine sawtimber stumpage 

prices exceed approximately $80/Mbf (Scribner) 

while holding hardwood prices constant at $90.36 

(Doyle), then intensive site preparation and planting 

is justified. When pine ranges between $50 and 

$80/Mbf, the inject residuals, plant pine option is 

somewhat better. In a weak pine sawtimber 

market, no investment in pine generation (i.e., 

natural option) is about as good as any other option. 

CONCLUSIONS 

Pine-hardwood stand dynamics are poorly understood. The simulation procedures in this analysis 

should be interpreted with considerable caution. 

The conditions for the study site may not be representative for the Cumberland Plateau in general and 

conc~usions should not be extrapolated to other 

regions. However, some useful inferences probably 

can be safely drawn from the results. They are: 

Intensive harvest of low-value hardwood stands 

in the Cumberland Plateau region would create 

an assortment of regeneration options. The I 

economically superior option depends heavily I 

I 

upon future prices for hardwood and pine sawtimber. 

*The superior growth rate of pine relative to 

hardwood for this site is sufficient to compensate 

for high pine establishment costs and low sawtimber stumpage prices for pine. 

*The mediocre site quality of the Plateau region 

apparently allows for successful establishment of 

a loblolly pine plantation with relatively less intensive site preparation than is possible for the 

South in general. Further replications of this 

study are required to verify this claim. 

*Overall investment returns from pure pine or 

pine-hardwood culture on the Cumberland 

Plateau may not compete favorably with non-timber investment opportunities. A 5.1 percent after 

tax, real, internal rate of return is attractive. 

However, risk, liquidity, and capital formation 

may still pose a barrier for many landowners. 

The risk associated with uncertain future prices, 

pine seedling mortality, and pests cannot be ignored. 
STBND BGE 

Natural + Plant Pine "Inject ii Plant Pine " Chop, Burn 8 Plant 

Figure 2.--SEV plotted over rotation age by 

regeneration option. 

Natural Plant Pine Inject & Plant Pine 

= REGENERATIOH OPTION Pine (Scribner) Hardwood (Doyle) 

Chop, Burn & Plant 

Figure 3.--Sawtimber volume yield by regeneration 

option. 
I I 

5 0 LOO 150 200 

Z PRICWMBF (Hardwood) 

" Natural -+ Plant Pine " Inject 81 Plant Pine " Chop, Burn & Plant 

Figure 4.--SEV plotted over hardwood sawimber 

stumpage price by regeneration option. 

5 PRICMBF (Binel 

Natural +PlantPine "Injeel4PlantPine A Cbp, hrn 4 Plant 

Figure 5.--SEV ploMed over pine sawtimber 

stumpage price by regeneration option. 
.I Expanding hardwood pulpwood demand may 

result in only moderately intensive harvesting if 

tree length logging is employed. This is because 

tree length loggers commonly cut down to a 6-8 

inch d bh minimum. Therefore, a substantial 

amount of residual hardwoods may remain to inhibit regeneration efforts. Costs for residual control may be higher than those assumed for this 

analysis. 

Intensive harvest of low-value hardwood stands in 

the Cumberland Plateau region is a means to an 

end, For private landowners interested in forest 

management, that end generally is the culture of a 

new crop of sawtimber stumpage products. An 

emerging hardwood pulpwood market may lead to 

a partial "cleaning of the silvicultural slate." 

However, speculation on future pine and hardwood 

sawtimber stumpage prices should drive the next 

decision, choosing a regeneration option. Our 

analysis showed that introduction of a loblolly pine 

component boosts volume yield and net economic 

returns relative to pure hardwood culture. 

Moreover, a pine component can be established following a shear harvest for about $100/acre before 

subsidies and reforestation income tax refunds. 

Considering the financial constraints faced by typical private landowners, however, this author 

believes that most lands harvested to meet growing 

hardwood pulpwood demand will be allowed to 

evolve naturally. Revenues from the sale of previously non-merchantable trees combined with increased growing space for desirable hardwood 

sprouts should mark a modest improvement over 

past conditions. 

ACKNOWLEDGMENTS 

The author thanks Dr. Charles E. McGee, Retired, 

U.S. Department of Agriculture, Forest Service, 

Southern Forest Experiment Station, Sewanee, TN. 

Preparation of this paper would have been impossible without Dr. McGee providing a tour of the 

study area and sharing data compiled by him and 

his staff. 

LITERATURE CITED 

Burkhart, Harold E.; Sprinz, Peter T. 1984. A model 

for assessing hardwood competition effects on 

yields of loblolly pine plantations. Publication 

No. FWS-3-84. School of Forestry and Wildlife 

Resources, VPI&SU, Blacksburg, VA. 55 pp. 

Dale, M. E. 1972. Growth and yield predictions for 

upland oak stands. Res. Pap. NE-241. Broomall, 

PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 

Faustmann, Martin 1849. On the determination of 

the value which forest tand and immature stands 

pose for forestry. In: Gane, M., ed. Martin 

Faustmann and the evof ution of discounted cash 

flow. Paper 42. Oxford, England: Oxford Institute; 

1968. 54 pp. 

Gingrich, S. F. 1964. Criteria for measuring stocking 

in forest stands. In: Proceedings Society of 

American Foresters. 198-201. 

Wepp, Todd E. 1987. A user manual for YIELDplus: 

Timber yield forecasting and planning tool. Tennessee Valley Authority, Morris, TN. 80 pp. 

McGee, Charles E. 1980, Expanding options for 

reforestation of the Cumbedand Plateau. 

Southern Journal of Applied Forestry 444): 158- 

162. 

McGee, Charles E. 1 982. Low-quality hardwood 

stands. Opportunities for management in the Interior Uplands. Gen. Tech. Rep. $0-40. New 

Orleans, LA: U.S. Department of Agriculture, 

Forest Service, Southern Forest Experiment Station. 22 pp. 

McGee, Charles E. 1986. Regeneration after shear 

felling and chipping of upland hardwoods. Res. 

Pap. SO-224. New Orleans, LA: U.S. Department 

of Agriculture, Forest Service, Southern Forest Experiment Station. 13 pp. 

McGee, Charles E. 1989. Converting low-quality 

hardwood stands to pine-hardwood mixtures. In: 

Waldrop ed., Proceedings from Pine-hardwood 

mixtures: A symposium on management and ecology of the type, April 18-1 9, Georgia-Pacific 

Center, Atlanta, GA, 

Neal, James; Norris, Frank 1989. Southern 

stumpage prices 1977-1 987. Forest Farmer 27th 

Manual Edition. 48(3):15-18. 

Skog, Kenneth; Ince, Peter; Spelter, Henry; Durbak, 

Irene; Howard, James 1988. Session IVB: Forcasting and facilitating adoption of technological 

innovations. pp. 65-67. In: Executive Summaries: 

42nd Annual Meeting, Forest Products Research 

Society, June 1 9-22, Quebec, Canada. 

Smalley, G.W.; Bailey, R.L. 1974. Yield tables and 

stand structure for loblolly pine plantations in Tennessee, Alabama, and Georgia highlands. Res. 

Pap. SO-96. New Orleans, LA: U.S. Department 

of Agriculture, Forest Sewice, Southern Forest Experiment Station. 81 pp. 

Straka, Thomas J.; Watson, William F,; Dubois, 

Mark 1989. Costs and cost trends for forestry 

practices in the South. Forest Farmer 27th 

Manual Edition. 48(5):8-14. 
MANAGED MIXED PINE-HARDWOOD STANDS CAN YIELD 

HIGH RATES OF RETURN ON INVESTMENT 

E. Carlyle ~ranklin' 

.-A simulation model was used to predict yields of natural stands of pure loblolly pine, 

mixed pine-hardwood, and a mixture of hard and soft hardwoods. A second model was used to 

predict yields of loblolly pine plantations with four levels of encroaching hardwood competition. 

Yields were predicted with and without thinning in all cases. Yields from a 30-year rotation were 

merchandized and analyzed economically in terms of internal rate of return and annual equivalent 

yield. Natural stands with 50 percent or less hardwood component were more profitable than artificially seeded stands of pure pine. Natural stands with 75 percent or less hardwood, and seeded 

stands with 50 percent or less hardwood exceeded the rate of return of the best plantation option. 

While natural and seeded stands of pine and mixed pine-hardwood had the highest rates of return, 

financial yields of several plantation options were high enough to be acceptable to many investors, even with some hardwood encroachment. There are many sites on which natural or seeded 

stands will not give favorable results. But where such stands will develop, they can be highly 

profitable. Mixed pine-hardwood stands are even more valuable where wildlife and aesthetic 

resources contribute to overall management goals. 

INTRODUCTION 

Economic criteria by which the quality of an investment is judged vary widely depending on differing 

investment objectives. Forest industry often sets a 

quota of wood to be produced at the lowest possible capital cost and may therefore elect to maximize volume per acre. A slightly differing scenario 

is characteristic of the private forest landowner with 

a fixed land base. Such an owner typically owns 

land for personal use such as recreation, estate 

building, and periodic income. This owner often 

elects to manage to maximize the value of benefits 

The objective of this study was to compare the internal rates of return (I RR) of natural, artificially 

seeded, and plantation stands of pure pine, mixed 

pine-hardwood and pure hardwood. Stands were 

grown using computer simulation with and without 

thinning, and with a wide range of typical establishment costs. 

METHODS 

Stand Growth and Yield Simulation 

per acre including timber, and therefore the present 

net worth concept of investment quality may be ap- Natural stand growth was simulated using the NC 

propriate. State University Natural Stand Simulator (Smith and 

Hafley per comm.) with and without thinning at age 

A third type of investor is one who looks primarily at 20, and with final harvest at age 30. Plantations 

return on investment as a measure of investment were simulated using the NC State University Plantaquality. The alternative rate of return (ARR) of the tion Management Simulator (Smith and Hafley 

best investment available is often used as a test 1986), with and without thinning at age 15, and with 

criteria. This type of *'pureu investor seldom choses 

timber growing investments. Within the last ten 

years institutional investors such as pension funds 

and insurance underwriters have sampled forest 

resource production investments. Individual investors responded vigorously for a time in the early 

1980's to certain limited partnerships offered by 

forest industries and nationally known invest ment 

firms. Certain forest management options may be 

financially attractive based on the "pure" investors' 

criteria, therefore it may be possible to attract substantial amounts of new capital into forest resource 

production. 

final harvest at age 30. All pine was loblolly, while 

hardwood represented an equal mixture of decurrent (oak) and excurrent (sweetgum) hardwood 

species. Site indices (base age 50) were 100 for 

loblolly pine, and 94 for mixed hardwood. Natural 

stands ranged from 100 percent hardwood to 100 

percent pine by 25 percent increments based on 

basal areas of typical natural stands of the pure 

species at age 20. The typical pure loblolly pine 

natural stand contained 309 trees per acre (tpa) 

with 123 square feet of basal area (ft2 ba) at age 20 

(Schumacher and Coile 1960). By contrast, the typical pure hardwood natural stand contained 681 tpa 

and 1 15 ft2 ba at age 20 (Gardner and others 1982). 

'Professor, Forestry Department. North Carolina State 

University, Raleigh, NC 27607. 
Table 1.--Stand characteristics and yields at age 20 of mixed loblolly pine-hardwood natural 

stands. site index (base age 50) pine: 100. hardwood: 94. with proportions gf stocking based 

percentages of basal area of typical pure natural stands of pine and hardwood 

Proportion Total Diameter Basal 

Treatlaen t of Hardwood Mean Height TreeslAcre Breast Height Area/Acre Total Yield 

Pine Hdwd Pine Hdwd Pine Hdwd Pine Hdwd Pine Hdwd 

(pet BA) ft ft (n) (n) (in) (in) (ftL) (ftL) (cd/a) (cdla) 

Un thinned 0 56 - 309 - 8,5 - 123 - 32.0 - 

25 56 53 232 170 8.5 5.6 92 29 23.9 6.1 

50 56 53 154 340 8.6 5.6 62 58 16.1 12.2 

75 56 53 77 511 8.6 5.6 31 86 8.1 18.1 

100 - 53 - 681 - 5.6 - 115 - 24.3 

After 0 59 - 187 - 9.4 - 90 - 25.0 - 

Thinning 25 57 53 156 123 9.0 5.6 68 21 18.3 4.4 

50 56 53 112 246 8.6 5.6 45 42 11.7 8.9 

75 56 54 55 340 8.6 5.8 22 63 5.7 13.7 

100 - 55 - 411 - 6.1 - 84 - 19.9 

a~mith and Haf ley ( 1986) ; Gardner and others ( 1982) . 

Thus the 50 percent pine-hardwood mixture con- Plantations were simulated with 0, 15, 30, and 45 

tained half of a typical natural pine stand (154 tpa percent encroaching hardwood competition based 

and 62 ft2 ba) plus half of a typical natural on total basal area at age 15. Initial pine stocking 

hardwood stand (340 tpa and 58 ft2 ba) (table 1 ). was 700 tpa with 85 percent survival, leaving 595 

Natural hardwood stands were thinned at age 20 to 

a residual basal area of 84 ft2. Natural pine stands 

were thinned to a residual basal area of 90 ft2. 

Residual stockings after thinning of mixed natural 

stands were proportions of the original stocking of 

each pure pine or hardwood type, therefore the 

residual stocking of the 50 percent hardwood mixture was 45 ft2 of pine and 42 ft2 of hardwood (table 

1). 

The natural stand simulator requires a parameter 

called the after/before diameter ratio. It is the ratio 

of the diameter after thinning divided by the 

diameter before thinning. Typical sizes are 1.0 (no 

change) to 1 .I (relatively large change). In this 

study, 1 .I was used for the pure natural stands. 

For the dominant species at 75 percent, 1.05 was 

used, and ratios at 50 and 25 percent were 1.0. 

tpa established. Pine was thinned to a residual 

basal area of 71 ft2 at age 15. The proportion of 

hardwood removed equaled the proportion sf pine 

removed when hardwood was present (table 2). 

Note that with 45 percent hardwood, only 7 ft2 ba 

was removed leaving residual basal area at 51 ft2, 

20 ft2 below the stands with higher pine stocking 

(table 2). Height over age curves used were by 

Smalley and Bower (1 971 ). 

Stand characteristics at age 30 in terms of basal 

areas and yields were generally proportional to 

stand characteristics at age of thinning, reflecting 

the proportional thinning of each type, and 

program logic which generally maintained proportional stocking through age 30. Comparison of 

mean and current annual increments indicated that 

all stands were close to volumetric culmination by 

Table 2.--Stand characteristics and yields at age 20 of loblolly pine plantations 

with four levels of hardwood competition, site index (base age 50) pine: 100, 

hardwood: 94, with 595 pines established to grow - 

Proportion Averagea Trees/ Basal 

Treatment of Hardwood Height Acre DBH Area/Acre Total Volume 

Pine Pine Pine Pin2 Hdwc) Pine Hdwd 

(pct BA) ft (n) (in) (ft 1 (ft (cd!a) (cdiai 

Un thinned 0 45 554 6.8 141 - 28.4 - 15 45 471 6.6 112 20 22.4 3.4 

30 44 387 6.3 83 36 16.7 6.2 

45 44 304 5.9 58 47 11.5 8.3 

After 0 47 217 7.7 71 - 15.0 - Thinning 15 47 244 7.3 71 12 14.8 2.3 

30 46 293 6.6 71 30 14.6 5.4 

45 45 240 6.2 51 4110.4 7.5 

%ominant height of pine was 49 ft. in all cases 
age 30 (table 3). Yields were merchandized for 

economic analysis. In plantations, the following 

minimum dimensions were used: 

Pine SaWimber - small end dib2 = 8 inches 

Pine Chip-n-saw - small end dib = 6 inches 

Pine Putpw~od-small end dib = 4 inches 

Hardwood SaMimber - DBH~ = 11 inches 

HardwoodPulpwood-BBH = Sinches 

tn natural stands, the fotlowing minimum dimensions were used: 

Transaction costs for various site preparation activities, sowing and planting, timber marking, taxes, 

fire protection and insurance were representative of 

average values in the southeast for the Piedmont 

and Coastal Plain (Straka and others 1989). All 

values are in 1988 dollarsiacre (table 4). 

Five different stand establishment scenarios were 

evaluated based on appropriate combinations of 

costs, with and without thinning costs, and includPine SaWimber and Chip-n-saw - DBM If 9 inches ing an annual maintenance cost of $3.1 Ziacrelyear 

Pine Pulpwood - 3BH = 5 inches (table 4). Unit prices for products were 1988 

Hardwood SaMimber - BBH = 11 inches acreage prices for the Piedmont of North Carolina 

Hardwood Pulpwood - DBH = 5 inches as reported in Timber Mart-South (Norris, 1988) 

(table 5). No inflationary or real price increases 

Conversion of cubic foot volume to cords and were assumed, so all inputs and results are in 1988 

board Feet were according to equations by dollars. 

Schumacher and Coile (1 960), with substitution of 

appropriate coefiicients for hardwoods (Hafley, per 

Economic analyses were done using Quick Silver 

cornm.) (Vasievich and others 1984). Parameters calculated 

were internal rate of return (IRR) . and annual r 

'Diameter Inside Bark, equivalent value (AEV) per acre. The IRR is the 

yield rate at which present value of costs equals "iametsr Breast Height (4.5 feet above ground line) present value of gains with intermediate cash flows 

Table 3,--Stand characteristics and yields of mixed pine-hardwood natural stands and plantations at 

final harvest age 30, without or with thinning at age 20 for natural stands, and age 15 for plantations 

St md Proportion Total Diameter Mean Annual Current Annual 

'bpe of Hardwood Mean Height Trees/Acre Breast Height Basal Area Increment Increment 

Pine Hdwd Pine Hdwd Pine Hdwd Pinq Hdwcj Pine Hdwd Pine Hdwd 

(pct BA)~ ft ft (n) (n) (in) (in) (ft ) (ft cds/ac/yr cds/ac/~r 

NATURAL 

Un thinned 0 7 2 - 205 - 11.5 - 149 - 1.8 - 1.5 - 2 5 72 68 153 160 11.5 6.4 111 36 1.3 0.3 1.1 0.3 

50 72 68 101 339 11.6 6.4 74 75 0.9 0.7 0.7 0.8 

75 72 68 50 508 11.6 6.3 37 111 0.4 1.0 0.3 1.1 

100 68 - 657 - 6.3 - 143 - 1.3 - 1.2 

NAT6"RAL 

Thinned 0 75 - 133 - 12.9 - 121 - 1.5 - 1.6 - 2 5 74 68 110 108 12.3 6.7 91 27 1.1 0.2 1.2 0.3 

50 72 68 79 237 11.8 6.7 60 58 0.7 0.5 0.7 0.6 

75 72 69 38 340 11.8 6.9 29 88 0.3 0.8 0.3 1.0 

100 - 71 - 415 - 7.2 - 116 - 1.1 - 1.3 

PLArnATf ON 

Thinned 0 73 - 198 - 11.4 - 141 - 2.0 - 2.0 - 

15 72 - 211 - 10.4 - 136 22 2.0 0.3 2.0 ., 

30 71 - 228 - 10.1 - 126 57 1.8 0.8 1.7 - 

45 71 - 180 - 10.0 - 98 79 1.4 1.1 1.4 - 

a For natural stmds - percent BA of typical hardwood stand on site 94 at age 20 (Gardner and others 1982). 

For plantations - percent of total BA (pine plus hardwood) at age 15. 

b~he hardwood component simulator is driven by basal area and does not generate charcteristics of 

individual trees, or current mnual increment. 
Table 4.--Present and future transaction costs for investments 

in natural stands and plantations (1988 dollars) 

Stand EstablishActivity Cost ment Scenario Cost 

Site Preparation by: Natural 0 

Shear-Rake-Pile 124.67 Direct Seeded 25.00 

chop 65.47 

Burn Burn-Plant 49.60 

Piles 5.00 

Chopped or slash 9.70 Chop-Burn-Plant 115.07 

Seeding (all inclusive) 25.00 

Shear-Rake-Pile 

Plant after: Burn-Plant 168.36 

Shear-Rake-Pile-Burn 38.69 

Chop-Burn 39-90 

Burn 39.90 

Maintenance: 

Insurance .15 

Ad Valorum Taxes 1.25 

Fire Protection 1.72 

TOTAL 3.12 

Mark Thinning in: 

Natural Stands 7.24 

Plantations 11.58 

Table 5.-- Unit prices for products hamested from mixed-pine 

hardwood natural stands and plantationsa 

Kduc t Price Unit 

$/unit 

Pine 

Pulpwood 11.63 cords 

Chip-n-saw 29.50 cords 

Sawtimber 129 .00 MBF (Scribner) 

Hardwood 

Pulpwood 4.58 cords 

Sawtimber 56.98 MBF (Scribner) 

Yimber Mart-South (Norris, 1988) . 

RESULTS 

All natural stands with up to 75 percent hardwood 

exceeded the profitability of the best plantation 

scenario (B urn-Plant-Thin) , as did ail seeded stands 

with up to 50 percent hardwood (table 6, figure 1). 

Thinned stands always exceeded unthinned stands 

in IRR. Relatively more benefit was obtained from 

thinning plantations and natural stands than from 

thinning seeded stands (figure 1). The rate of 

decrease in profitability was much higher for plantation scenarios than for natural stands as proportions of hardwood basal area increased up to 50 

percent. From 50 percent on, natural stands had 

equal or higher sensitivity to increasing proportions 

of hardwood than plantations, as measured by IRR 

(figure 1). 

Chop-Burn-Plant 

Shear-Rake-Pls Burn-Plant-Thin '4 

Hardwood Bad Area (percent) 

invested at the IRR. The AEV is the net worth of the Figure 1 .--Internal rates of return for investments in 

scenario paid in equal annual annuity payments thinned and unthinned natural stands and plantaover the entire rotation. The IRR is independent of tions of pure pine and hardwood, and pine- any discount rate in its ca/culation. It indicates the hardwood mixtures with differing establishment ARR at which the value of the enterprise is 0. If the costs and an annual carrying cost of $3.1 2iacrelyr ARR is less than the IRR, the enterprize is through a 30-year rotation. profitable. If the ARR exceeds the IRR, the 

enterprise is not profitable. t-iow profitable or unprofitable is indicated by the AEV at a specified 

AR R. DISCUSSION 

What rate of return on investment is likely to attract 

new capital to management of forest resources? 

One place to look for alternative rates is the government guaranteed, mortgage backed securities offered by the Government National Mortgage 
Table 6.-- Economic charactiesistics of investments in mixed pine-hardwood 

natural stands and plantations, thinned and unthinned, with differing 

establishment costs and an mual maintenance cost of $3.12jac/yr through 

a 30-year rotation 

Internal 

Proportion Rate of Annual Equivalent Value f $/a) 

Stmd Type of Rdwd Return at Discount Rate of: 

Un thinned 0 18.5 4 8 34 23 15 9 

25 17.1 3 6 25 17 11 6 

50 15.4 24 17 11 6 3 

7 5 12.7 13 a 5 2 o 

100 5.9 I 0 - 1 - 2 - 2 

DIRECT SEEDED 

Thinned 0 15.0 4 4 30 19 11 6 

25 13.9 3 2 22 14 8 3 

50 12.5 21 14 8 4 1 

75 9.9 10 6 3 -0 - 2 

100 3.8 0 - 2 - 3 - 4 - 5 

Unthinned 0 

25 

50 

7 5 

100 

FLkrSFATfONS 

Burn 0 

Thinned 15 

30 

4 5 

Un thinned 0 9.7 17 10 4 - 1 - 4 

15 8 * 9 13 7 2 - 2 -5 

30 7.8 8 3 0 -3 - 6 

45 6.7 5 1 -2 -5 -7 

Chop-Burn 

Thinned 0 8.4 3.7 8 1 - 5 - 9 

15 7.4 13 5 -2 - 7 -12 

30 6.4 8 1 -4 - 9 - 13 

45 5.5 5 -I -6 -10 -14 

Un thinned 0 

15 

30 

45 

StimEi-UKEPILE-BL%N 

Thinned 0 

15 

30 

45 

 or natural stands - percent of BA of typical hardwood stand on site 94 at 

bage 20 (Gardner and others 1982). 

For plantations - percent of total EA (pine plus hardmod) at age 15. 
Association (GNMA). Average net yields to investors based on prepayment in 12 years on pools of 

30-year-FHWA mortgages from 1983 to early 1986 

ranged from 13.1 to 9.4 percent (Wiedemer 1987). 

if the inflation rate is about 3 percent, then an investor may be willing to accept a minimal average real 

rate of return of about 8 percent. In our recent experience with investors in partnerships minimum 

ARR's were 11 to 12 percent, so the 8 percent real 

rate minimum seems realistic. 

Thinned natural stands were the best pedormers 

based on investment criteria under the conditions 

and assumptions of this study. Even with 50 percent hardwood, thinned natural stands exceeded 

the profitability of direct seeded and thinned pure 

loblolly pine (figure 1). Of course to accomplish 

this high rate of return, high proportions of pine 

must become established in naturally developing 

stands. A pine seed source must be present, atherwise direct seeding is the next lowest cost option. A 

seed bed must be prepared by prehawest fire or 

scarification during logging, and the harvest must 

be timed to catch the seed fail. 

When mixed pine-hardwood stands develop with 50 

percent or more pine the highest rates of return 

may be enjoyed (figure 1). However, one may be 

well advised to do one or more of the activities suggested above to help in obtaining a naturai stand 

with a high proportion of pine. But with 75 percent 

hardwood, the natural stand IRR was about equal 

to that of a $25/acre investment in direct seeding 

resulting in 25 percent hardwood. Therefore, the 

amount of investment in such activity must be conservative. The most important thing is to recognize 

those stand and site combinations which will 

respond well to low cost approaches, and do not attempt such approaches on stands and sites which 

will not. The investor seeking high yields in the 

range of 1 0 to 1 2 ARR, will be limited to those stand 

and site combinations which respond favorably to 

low cost approaches. 

Only the highest yielding plantation options exceeded an 8 percent IRR. Therefore most plantation options will yield either negative or very low 

profits at an 8 percent alternative rate of return. In 

fact, the highest yielding plantation scenario yielded 

$7/acre/year at 8 percent alternative rate of return 

(table 6). This resulted from an IRR of 1 1.2 percent, 

obtained in a burned only, thinned, pure pine plantation (figure 1). Therefore, under the conditions 

and assumptions of this study we conclude that the 

investor will be limited to the lowest cost plantation 

options, and that profits will be modest at best. 

However, plantations desewe a second look from 

the point of view of the investor in typical ceutiflcates of deposit or common stocks which have 

yields in the range of 9 to 11 percent. Substracting 

3 percent for inflation, this is equivalent to a 6 percent minimum real rate of return. Most plantation 

scenarios exceeded 6 percent in IRR (figure 1). 

Profit from the best plantation scenario at 6 percent 

ARR was $13 per acreiyear (table 6). Very substantial improvements in yield rates for plantations can 

be obtained with cost-sharing. For example, the 

yield rate of chop-burn-plant with 60% cost-share is 

about equal to the yield rate of burn-pliant, a net increase of about 2.8 points. Therefore, plantation options desewe consideration by some forest 

resource investors. 

LITERATURE CITED 

Gardner, W, E.; March, P,; Kellison, Re C.; 

Frederick, 8. J. 1982. Yields of natural 

hardwood stands in the southeastern United 

States. Hdwd. Res. Coop. No. I. Coil, sf For. 

Resour., NC State Univ., Raleigh, NC. 64 pp. 

Norris, F. W. 1988. Timber Marl-South 13(4). Timber Marl South, Inc., Highlands; NC, 

Schumacher, F. X.; Coile, 9, S. 1966. GroMh and 

yield of natural stands in the southern pines. Y. 

S. Coile, Inc., Durham, NC. 115 pp. 

Smalley, G. W.; Bower, B. R. 1971. Site index CUPves for lobiolly and shortleaf pine plantations on 

abandoned fields in Tennessee, Alabama and 

Georgia highlands. U. S. Forest Sewice, Files. 

Note SO-1 26. 6 pp. 

Smith, W. D.; Hafley, W. L.. 1986. Evaluation of a 

loblolly pine plantation thinning model. Southern 

Journal of Applied Forestry 10:52-63. 

Straka, T. J.; Watson, W. F.; Dubois, M. 1989. 

Costs and cost trends for forestry practices in the 

south. Forest Farmer Manual 48(5):8-14. 

Vasievich, J. M.; Frebis, R.; Wiethe, R. W. 1984. 

Quick Silver: The forestry investment analysis 

program. [Computer program]. U.S. Departmen"if Agriculture, Forest Setvice, Southeastern 

Forest Experiment Station, Research "Tiangle 

Park, NC. 

Wiedemer. J. P. 1987. Real Estate Finance. Prentice-Halt, Inc., Englewssd CliFls, NJ. 396 pp. 
HARDWOOD MATERIAL USE: PAST, PRESENT, AND 

FUTURE 

William G. ~uppold' 

. -There have been dramat~c changes in the consumption of hardwood p~oducts over the 

last 30 years. Product~on of hardwood pallets and kitchen cabinets have soared while production 

of household wood furniture has shown less growth. There also has been major growth in the 

production of lower value hardwood pulpwood and the exportation of higher value hardwood lumber, logs, and veneer. Trends in domestic consumption, economic activity in Europe and Asia, 

and concerns over clearing and logging activities on tropical land indicate that demands for 

hardwood products should continue to increase through the remainder of this century, 

INTRODUCTION 

Over the last 30 years there have been dramatic 

changes in the consumption of hardwood products. 

Pallets, kitchen cabinets, and exports have grown 

from minor importance to become three of the top 

five markets for hardwood lumber. Hardwood 

pulpwood has become one of the top two markets 

for hardwood industrial roundwood. This paper examines these changes and discusses future use of 

hardwood products in major end markets. 

Specific topics examined in this paper are domestic 

hardwood lumber use, hardwood product exports, 

and pulpwood production. The domestic markets 

for hardwood veneer and plywood have been excluded due to the lack of consistent historical data. 

DOMESTIC HARDWOOD LUMBER USE 

Hardwood lumber probably is the single most important product derived from the eastern hardwood 

forest on a value basis. One difficulty encountered 

in making an absolute statement on the importance 

of this product is that official estimates of hardwood 

lumber production appear low. Estimates of total 

hardwood lumber use by Cardellichio and Binkley 

(1983) based on a use-factor approach and estimates of hardwood lumber production (Luppold 

and Dempsey, in press) are consistently higher 

than hardwood production estimates reported by 

the U.S. Bureau of the Census (Current lndustrial 

Reports) (figure 1 ). 

Estimates of industrial hardwood lumber use 

derived from the Census of Manufactures indicate 

that industrial consumption alone has been greater 

than reported production since the early 1970's 

(table 1 ). Also, the information in table 1 indicates 

that hardwood lumber consumption by major industrial user has increased dramatically in the 

1980's. The most striking increase in demand was 

Billion Bd. Ft. 

Figure 1 .--Comparison of Current Industrial Reports 

hardwood lumber production volumes to Cardellichio and Binkley usage volumes and Luppold and 

Dempsey production volumes. 

by the pallet and container industries. The estimates provided in table 1 combined with the information in figure 1 indicate that pallet and container 

industries used more than 40 percent of the lumber 

apparently consumed in 1986. 

Another major shift indicated in table 1 is that, after 

25 years of relatively stable demand, use of lumber 

in the furniture and cabinet industry seems to be increasing. Although the wood household furniture industry is still the largest single user of hardwood 

lumber, the cabinet industry has shown the greatest 

increase in level of employment and apparent 

demand. 

Production of hardwood dimension and flooring 

also has increased substantially during the 1980's. 

The increase was due to both a 20-percent increase 

in wood furniture production and a 96-percent increase in wood flooring production between 1982 

and 1986 (Nolley 1988). It should be noted that 

'Project Leader, Northeastern Forest Experiment Station, Princeton, WV. 
Table 1.--Hardwood lumber consumption by major end-use products, selected yearsa 

Million board feet 

b Furniture and cabinets 1606 1986 1970 1970 2096 1987 2454, 

Dimension and flooringC 1502 1790 1503 1452 1384 1149 1660, 

Millwork 245 242 354 534 472 500 780, 

Plpood, structural members, 177 113 147 399 478 440 440 

and prefab buildings 

Wooden boxes. pallet containers. 987 1746 2443 2418 2627 3184 4680~ 

and wgod products NEC' 

Rail ties 775 500 650 850 1000 834 5Mf 

Exports 

Total consumpticn 

Total produc tiftng 

'~xcept where noted, figures are from Luppold 1987. 

b~stimated from the change in deflated value of shipments from U.S. Department of 

Commerce, International Trade Administration' s 1986 U. S. industrial outlook and 

change in employment from unpublished U.S. Department of Labor data. 

ilncludes lumber produced within the plant. 

No attempt made to estimate 1986 use, so 1986 figures are included for accounting 

purposes. 

e~ailroad tie lumber-usage level developed from Cardellichio and Binkley's 1984 

festimates for 1963-82. 

Developed from rail ties production estimates (American Wood Preservers' 

Association 1986). 

g~. s . Department of Commerce, Bureau of the Census, Current Industrial Reports, 

even after the tremendous increase in wood flooring 

production in the 1980'~~ flooring production is just 

25 percent of the level produced in the early 1960's 

(U.S. Department of Commerce, Bureau of the Census 1987). 

Even though table 1 indicates that apparent usage 

is greater than estimated production, these demand 

estimates still are lower than estimates by Luppold 

and Dempsey (in press) of eastern and central lumber production adjusted for changes in millstocks, 

western productions, and imports (table 2). The differences between the latter estimates and estimates 

of apparent usage probably stem from nonind ustrial uses and nonreported industrial uses. 

Home and farm-building construction probably was 

the largest nonindustrial use prior to 1970. Nanreported industrial uses include dunnage, blocking, 

mine timber, and other industrial products purchased directly from sawmills. Most of these nonindustrial or hidden industrial uses apparently have 

subsided with the introduction of alternate material 

or alternate manufacturing and transp~flation 

processes. 

The negative difference between total apparent consumption and industrial consumption that occurred 

in 1982 could be due to the inaccuracy of the estimation techniques employed. It atso might be explained by the reductions in lumber inventories held 

Table 2.--Comparison of hardwood consumption against Luppold and Dempseyk hardwood 

production estimates 

Luppold 

and Changea 

Year Dempsey in mill 

(in press) stocks 

Total Consumption 

Western Imports apparent by industry Difference 

Million board feet 

a Estimated by taking the product of the Luppold-Dempsey multipliers times the U,S, 

Department of Commerce, Bureau of the Census estimate of millstocks, 
by brokers or furniture plant lumber yard stocks in 

the early 1980's. These reductions resulted from 

the high interest rates and slack business conditions during this period. Conversations with wood 

buyers indicate there was a significant reduction of 

inventories by hardwood-using and distributing industries in the early 1980's. Low inventory levels 

persist today as firms try to minimize inventory 

costs. 

HARDWOOD PRODUCT EXPORTS 

Exports of hardwood logs, lumber, and veneer have 

increased during the last 30 years. Of the three 

major hardwood products exported in 1986, 

hardwood lumber was the most important, accounting for 66 percent of the total value and 77 percent 

of the total volume on a board-foot basis (Luppold 

and Araman 1988). Between 1960 and 1972, exports of hardwood lumber fluctuated between 1 10 

and 170 million board feet (MMbf) per year (figure 

2). Between 1972 and 1986, exports of hardwood 

lumber increased from 160 to 549 MMbf. 

Figure 2.--Hardwood lumber exports, 1960-1 986. 

Analysis of hardwood lumber exports during the 

last 15 years shows three distinct periods of market 

change (figure 2). During the 1970'~~ exports to 

Europe increased rapidly due to the devaluation of 

the U.S. dollar and increased economic activity in 

Europe (Luppold 1984). In the early and mid1980's, the dollar increased against European currencies and exports to Europe dropped. However, 

total exports of hardwood lumber stabilized during 

the early 1980's because the drop in European exports was matched by an increase in shipments to 

Japan and Taiwan. Since 1986, exports have increased substantially to ail major markets. 

Oak has consistently been the major hardwood 

species of lumber exported in the post-World War It 

era. In 1986, nearly 50 percent of the hardwood 

lumber exports were red oak and 18 percent were 

white oak (Ulrich 1 988). Since exports contain relatively large volumes of higher grade lumber, the 

surge in exports has caused a dramatic increase in 

the prices of higher grade oak, ash, and cherry lumber. These price increases apparently have caused 

an increase in demand for high-grade logs and timber sites containing a high proportion of these 

species. 

Hardwood logs are the second most important 

hardwood exported product, accounting for 18 percent of the dollar value and 19 percent of the 

volume of total hardwood product exports in 1986 

(Luppold and Araman 1988). Unlike lumber exports, log exports increased gradually during the 

post-World War I1 period, with noticeable increases 

in the 1960's, 70's and 80's (figure 3). 

Figure 3.--Hardwood log exports, 1960-1 986. 

Apart from physical- or dollar-volume trends, log exports over time can only be generalized. In the 

1950's and 60's, black walnut was the most important log species exported on a dollar-value basis. 

In the 19701s, black walnut still accounted for 76 percent of the dollar value and 25 percent of the physical volume of log exports. The increase in oak 

lumber exports to Europe in the mid- and late1970's coincided with an increase in oak log exports. By 1979, shipments of oak made up 47 

percent of the physical volume while shipments of 

black walnut dropped to 5 percent of the physical 

volume (Ulrich 1988). 

Hardwood veneer exports accounted for 4 percent 

of the total board-foot volume and 17 percent of the 

dollar value of total hardwood product exports in 

1986 (Luppold and Araman 1988). Similar to lumber exports, veneer exports to Europe increased 
rapidly in the early 1970's. Similar to the log 

market, oak veneer exports surpassed walnut 

veneer exports as a result of the surge in European 

demand for oak. In 1970, 60 percent of the veneer 

exports were walnut while 39 percent were oak and 

other species. By 1980, 11 percent of the veneer exports were walnut while 59 percent were oak. Unlike lumber, white oak accounted for 40 percent of 

the veneer shipments while red oak accounted for 

24 percent (Ulrich 1988). This difference between 

the lumber and veneer markets was caused by the 

large impact of German demand for white oak 

veneer. 

HARDWOOD PULP DEMAND 

Since hardwood fibers are shorter and less flexible 

than softwood fibers, paper products containing 

mostly hardwood pulp tend to be weaker than their 

softwood counterparts. Historically, this made 

hardwood pulp less preferred than softwood pulp in 

many paper-making activities. However, the combination of new technologies, changing paper 

product markets, and the relatively low price of 

hardwood pulpwood has caused the consumption 

of hardwood pulp to expand. 

Between 1956 and 1986, hardwood increased from 

17 percent of the demand for pulped material to 30 

percent of the total market (Ut rich 1988). This represents a 370-percent increase in hardwood 

pulpwood production compared to a 172-percent increase in softwood pulpwood production during the 

same period. However, the increase was not 

uniform across regions (table 3). The largest 

amount of increase was in the South. On a percentage basis, however, the West experienced the 

largest percent increase in hardwood pulpwood 

in the South. Some of this change can be attributed to the growth of the southern pulp industry 

in general, but overall hardwood usage has increased by more than 500 percent while softwood 

usage has increased by less than 150 percent. 

These trends have increased hardwood's share of 

the southern pulpwood market from 14 percent in 

1956 to nearly 30 percent in 1986 (Ulrich 1988). 

Production of northern hardwood pulpwood also 

has increased dramatically over the last 30 years. 

In absolute terms, hardwood pulpwood production 

increased by more than 6 million cords while 

softwood production increased by slightly more 

than 1 million cords (Ulrich 1988). These changes 

in production increased hardwood pulpwood's 

market share from 41 percent in 1956 to 63 percent 

in 1986. 

The variation of hardwood pulp production for 

specific products is quite marked between regions 

(table 3). A large share of hardwood pulpwood 

produced in the South is consumed in semi-chemical (paperboard) newsprint production (Ince and 

others, in press). For these and other products, increasing amounts of hardwood pulp (1 7 to 18 percent) are combined wilh sowsod pulp to make 

products that were mostly softwood pulp 20 years 

ago. The majority of hardwood pulp produced in 

the northern region is used to produce writing 

paper and tissue. 

WHAT DOES THE FUTURE HOLD? 

Given current information, hardwood lumber usage, 

export demand, and hardwood pulpwood production can be expected to increase through t he 

remainder of this century. 

production. One major factor that will influence future demand 

In absolute terms, nearly 80 percent of the total U.S. for higher quality hardwood lumber is the maturing 

increase in hardwood pulpwood consumption was of the baby boomers matched with the apparent 

Table 3. --Hardwood and softwood pulpwood production in 1956, 1966, 1976, and 

1986, by region (Ulrich 1988) 

Percentage 

Species group Production change in 

and region 1956 1966 1976 1986 production 

Million cords 

Hardwood 

North 3.0 5 - 9 7.4 9.5 217 

South 2.9 7.7 11.2 17.9 517 -. 

West 0.2 0.6 0.7 1.3 550 

Total 6.1 14.1 19.3 28.7 370 

Softwood 

North 4.4 4.4 4.8 5.7 30 

South 17.4 25.4 36.2 42.7 

West 7.3 12.2 17.1 16.3 123 

145 

Total 29.1 42.0 58.1 64.7 122 
quality appeal of hardwood products. The furniture, cabinets, dimension, flooring, and millwork industries used nearly 5 billion board feet of 

hardwood lumber in 1986, an increase of 1 billion 

board feet over 1977. This increase coincided with 

the increase in the 25- to 44-year-old population 

(figure 4). As this age group is increasingly tied to 

home activities, demand for such products as furniture, fancy wood fixtures, and cabinets can be expected to increase. A striking example ot the 

influence of this population group is the resurgence 

in the use of wood flooring. 

Millions 

100 

Figure &-Level of population between 25-45 years 

of age, (actual and projected), 1 960-2000. 

Increased use of low-grade hardwood lumber by 

the pallet industry also can be expected. Pallets are 

a low-cost part of capital-intensive material handling 

systems (Luppold and Anderson 1986). As industrial production and labor costs increase, the installation of systems utilizing hardwood pallets also 

can be expected to increase. On the other hand, if 

a more functional pallet exchange system is 

developed utilizing a more durable pallet, lumber 

use could decrease while pallet use continues to increase. 

Factors that indicate an increase in hardwood 

product exports include: (1) the continuing high 

U.S. trade deficit that will keep the value of the U.S. 

dollar low relative to European and Asian currencies; (2) environmental concerns over clearing and 

logging activities on tropical land combined with 

limited supplies of temperate timber outside of the 

United States; (3) the development of consumerbased versus producer-based economies in Japan 

and other Asian countries; and (4) art expanded 

European economy resulting from the dropping of 

all inter-Common Market trade barriers in 1992. 

Some factors that may hinder exports of hardwood 

products are: (1) the liquidation of forest resources 

by Third World countries to reduce their indebtedness; (2) escalation of trade tension with European 

and Asian nations leading to trade wars; and (3) a 

major interruption of international financial markets 

leading to decreased worldwide economic activity. 

It is difficult to say whether the factors facilitating 

trade will outweigh the factors that may hinder it. 

As demand for hardwood lumber increases, so will 

the availability of low-cost hardwood pulp material. 

Projections by lnce and others (in press) indicate 

substantial increases in hardwood pulpwood con- 

-+ sumption in all U.S. regions and for most paper and " board products. Hardwood pulpwood will continue 

to displace sodtwctsd pulpwood production in the 

North, while hardwood pulpwood production will 

grow at a faster rate than softwood pulpwood 

production in the South. 
LITERATURE CITED 

American Wood Preservers' Association. 1 980. 

Wood preservation statistics. Stevensvitfe, MD: 

American Wood Preservers' Association. 

Cardellichio, Peter A.; Binkley, Clark S. 1984. 

Hardwood lumber demand in the United States: 

1 950 to 1980. Forest Products Journal. 34(2): 15- 

22. 

he, Peter J.; Durbak, Irene; Howard, James L. 

Pulpwood model--data, assumptions, preliminary 

results. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 

fin press] 

Luppold, William G. 1984. An analysis of European 

demand for oak lumber. Res. Pap. NE-538. 

Broomall, PA: U.S. Department of Agriculture, 

Forest Service, Northeastern Forest Experiment 

Station. 7 p. 

Luppold, William G. 1987. The changing hardwood 

lumber market. In: Hay, Ronald L.; Woods, Frank 

W. ; DeSelm, Hal., eds. Proceedings, Central 

Hardwood Forest Conference 6; 1 987 February 

24-26; Knoxville, TN. Knoxville, TN: University of 

Tennessee: 401 -408. 

Luppold, William G.; Anderson, R. Bruce. 1986. A 

regional analysis of pallet supply and demand. 

Wes. Pap. NE-580. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern 

Forest Experiment Station. 8 p. 

Luppold, William G.; Dernpsey Gilbert P. New estimates of central and eastern U.S. hardwood 

lumber production. Northern Journal of Applied 

Forestry. [in press]. 

Luppold, William G.; Araman, Philip A. 1988. 

Hardwood trade trends: U.S. exports. Res. Pap. 

NE-61 t . Broomall, PA: U.S. Department of 

Agriculture, Forest Service, Northeastern Forest 

Experiment Station. 10 p. 

Nolley, Jean W. 1988. Bulletin of hardwood market 

statistics: summer 1988. Gen. Tech. Rep. NE-121, 

Broomall, PA: 14 .S. Bepaatment of Agriculture, 

Forest Service, Northeastern Forest Experiment 

Station. 23 p. 

Ulrich, Alice H. 1988. U.S. timber production, trade, 

consumption, and price statistics 1 950-1 986. 

Misc. Publ. No. 1460. Washington, DC: U.S. 

Department of Agriculture, Forest Service. 81 p. 

U.S. Department of Commerce, Bureau of the Census. 1987. Statistical abstract of the United 

States: 1988 (1 08t h edition). Washington, DC: 

U.S. Department of Commerce, Bureau of the 

Census. 943 p. 

U.S. Department of Commerce, Bureau of the Census. 1966-1 986. Census of manufactures. 

Washington, DC: U.S. Department of Commerce, 

Bureau of the Census. 

U.S. Department of Commerce, Bureau of the Census. 1966-1 986. Current industrial reports. 

Washington, DC: U.S. Department of Commerce, 

Bureau of the Census. 

U.S. Department of Commerce, lnternational Trade 

Administration. 1986. 1986 U.S. industrial outlook. Washington, DC: U.S. Department of 

Commerce, International Trade Administration. 

419+ p. 
MANAGEMENT OPTIONS WHEN LOBLOLLY PINE 

REPRODUCTION INVADES A CLEARCUT INITIATED FOR 

HARCIWBODS 

Roger W. ~ennin~ton' 

Abstract. -In south M~ssrss~ppt ioblolly pine seeded into stream bottom clearcuts where 

hardwoods were the preferred forest type. Analysis of data collected nine years following site 

preparation treatments shows that several management options are available which will accommodate a range of management objectives, Three basic management opt~ons are presented: (1) 

optimized wildlife benefits with a hardwood forest type, (2) optimized timber revenues with a loblolly pine forest type, and (3) a compromise between option one and two with a pine-hardwood forest 

type at a level where both wildlife benefits and timber revenues produce acceptable outputs. All 

three options can be accomplished at low investment cost and with high returns. 

INTRODUCTION 

Foresters and wildlife biologists on the DeSoto National Forest in south Mississippi expect the streambottom sites to produce much of the hard mast 

needed to carry desired wildlife populations. These 

sites represent only 11 percent of the total commercial forestland (CFL) acres on that national forest. 

The remaining 89 percent of CFL on this 500,000 

acre public forest is deemed best suited for growing 

the longleaf, slash, and loblolly pine forest types. 

Past management practices and wildfires have 

made the hardwood timber quality and hard mast 

production on the bottomland sites less than optimum. The most effective way to increase the 

hard mast production of these stands is to 

regenerate them and favor the oak component as 

the future stand develops. In the mid 1970's one of 

the DeSoto National Forest districts embarked on a 

hardwood regeneration initiative. The Chickasawhay District in Greene, Jones and Wayne 

Counties has approximately 27,000 acres of bottomland sites out of its 150,000 acre total. An average 

of 130 acres of the bottomland sites were 

regenerated each year. Stand size averaged 20 

acres. 

In order to concentrate regeneration efforts on the 

least mast productive sites first, a regeneration 

protocol was established (table 1 ). Often stands 

containing a high component of loblolly pine were 

harvested for the purpose of regenerating a 

hardwood stand. This paper reports on two such 

stands nine years following the harvest cut and site 

preparation. Management options are suggested 

that may be suited to both public and private forest 

landowners. 

%ilviculturist, USDA Forest Service, Southern Region, 

Atlanta, GA. 

Table 1. Regeneration priority for hardwood sites on 

the Chickasawhay District - DeSoto National Forest 

Priority Pre-harvest condition 

1 Sparse hardwood growing stock 

2 Low-quality hardwood growing stock 

3 Stands with high components of pine 

4 Over mature hardwood 

NOTE: Stands averaging < 30 square feet basal area 

per acre of acceptable hardwod growing stock not 

eligible to regenerate. 

DESCRIPTION OF THE AREA 

The two stands forming the basis of this paper are 

located on Trebloc soils characterized by poorly 

drained soils that formed in moderately fine textured alluvial sediment in stream terraces and flood 

plains. Slopes are 0 to 2 percent. The soils of the 

Trebloc series are fine-silty, siliceous, thermic Typic 

Paleaquults. 

No detailed stand composition data were collected 

prior to harvest. It is reasonable to assume that the 

original stand is represented by adjacent uncut 

stands on the same soils. Here loblolly pines in 

large 18-inch plus diameters are scattered and 

clumped over a mid-story of laurel oak, water oak, 

blackgum, red maple, and southern magnolia. The 

pine basal area ranges from 10 to 100 square feet 

per acre. Dominant pines average 20 inches DBH 

and 100 feet in height. Few pines under 16 inches 

are a component of these stands. Hardwoods are 

smaller in diameter and height. Based on height 

over age curves for natural loblolly pine, on-site 

measurements suggest the site index (base 50 

years) for loblolly pine is 100. Soil-site conditions 
were measured using Baker and Broadfoot's guide 

to determine the site quality rating (SQR) for water 

oak to be 70 to 75 (Baker and Broadfoot 1979). 

After all merchantable pine and hardwood stems 

were removed in a commercial clearcut in 1978, the 

stands were site prepared by shearing in October, 

1979. The shearing was accomplished with a Vblade on a crawler tractor in the Forest Service 

fleet. Soil disturbance and hardwood root damage 

was minimized by keeping the blade 2 to 3 inches 

above the ground. Tractor production averaged 4 

to 5 acres per hour. Based on competitively bid 

contracts of site preparation by shearing in similar 

conditions, the cost would have been $35 to $45 

per acre. 

RESULTS 

Nine years after site preparation the stands were inventoried using a series of randomly located 111 00 

acre plots. As had been anticipated, loblolly pine 

seeded in from adjacent uncut stands and was 

clearly the dominant species of the new stand. 

Loblolly pine composed over 90 percent of the total 

biomass (table 2). The maple group folowed with 5 

percent and the important oak group with 1.6 percent. Species were iumped into five groups for purposes of discussion (table 3). 

Table 3. Species groupings 

Group Species 

Pine Loblolly Pine 

(negligible) Spruce Pine 

Maple Red Maple 

Gurn Black 

Oak 

Other 

Water Oak 

Laura1 Oak 

Post Oak 

White Oak (alba) 

Sassaf rass 

Black Cherry 

Persimmon 

Sweet Bay 

Dogwood 

Table 4. Stand composition 9 years 

after site preparation 

Table 2. Species group biomass at age 9 

Species Group Trees per acre 

Species group Percent of woody biomass 

Pine 

Maple 

Gum 

oak 

Other 

The stand composition was dominated by maple 

and loblolly pine with 1,938 and 1,908 trees per 

acre (IPA) respectively (table 4). Gum followed 

with 369 and the oaks with 31 6 TPA. Total TPA 

averaged 4,762. 

iobloliy pine was the most dominant in size of all 

species. It averaged 4.1 inches DBH and 25.0 feet 

in total height on dominants and co-dominants at 

the time of inventory (table 5). Most of the 

dominant pines were 7 to 8 years old. Oak stems 

that were largest averaged 1.5 inches DBH and 17.1 

feet total height. 

Pine 

Maple 

Gum 

O& 

O thers 

Total 

Table 5, Size of dominants and codominants 

9 years after site preparation 

Species Group DBH Total Height 

Pine 4.1 25.0 

Maple 1.2 16.2 

 an 1.8 17 9 3 

Oak 1.5 17.1 

other 0-8 12.7 
It was apparent from the range of sizes and increment borings that the loblolly pines came from 

three or four seed years. The larger stems 

originated from the earlier seed crops and smaller 

seedlings, in the 2 to 3 foot height class, from subsequent crops. 

MANAGEMENT OPTIONS 

Several management options are available at this 

time in the life of these young stands. As time 

progresses, some options will be more difficult to execute and capture the full benefits. Ideally, 

managers should select their long-term objectives 

within the first years of the stands' establishment. 

For simplification, three options are presented: (1) 

managing to maximize wildlife habitat, (2) managing to maximize financial returns from timber 

receipts, and (3) managing to blend the wildlife and 

financial benefits without overly compromising 

either. 

Wildlife Habitat O~tion 

In the context of total forest management, these 

stands will contribute the most to wildlife habitat if 

managed for hardwood forest types. Optimum native game habitat for most preferred species should 

contain hard mast capacity. 

Deer, turkey, and squirrel are major wildlife groups 

that benefit from a hard mast component in their 

diets. At this point in time with the two stands in 

question, something must be done to lessen the 

dominance of the pine and increase the presence of 

the mass producers, the oaks and gums. Blackgum 

is a desirable stand component because of its soft 

mast production and tendency to produce nesting 

cavities sooner and more frequently than most 

other species. 

Because of the rapid growth of the pine, a commercial cleaning is needed by age 12 to 15. By then 

dominant pine stems should average 6 to 8 inches 

DBH. The cleaning procedure, which could also be 

considered a release treatment or a thinning from 

above, should be designed to remove pines that 

overtop desirable hardwoods. This procedure will 

need to be repeated every 8 to 12 years until the 

pine has been converted from the major component to a subordinate or minor component of the 

stand. Merchantable pine stems that do not compete or are not expected to compete with desirable 

hardwood stems should be left. This keeps the entire site fully occupied with either pine or desirable 

hardwood. On each subsequent entry, each pine 

stem must be judged again as to its removal or 

retention. 

The removal of pines is a delicate operation which 

will require the greatest of sale administration skills. 

Directional felling, carefully located skidding lanes, 

and complete limbing before skidding are but some 

of the techniques that must be employed to prevent 

unacceptable damage to the hardwoods. Pines to 

be removed should come out of the stand as early 

as possible to minimize hardwood damage. 

But what about the small size and slow initial 

growth of the oaks during the first 9 years? Will the 

oaks do better? How will they fare with the other 

hardwoods? Must other hardwoods be removed by 

some release and weeding operation to favor the 

oaks? Clearly the oaks will never overcome the aggressiveness of the pines without help in the form of 

pine removal. Stand dynamics varies by site and 

species, but generally oak is a slow starter that 

begins to move from a subordinate to a dominant 

crown position by age 20 to 25 (Clatterbuck and 

Hodges 1988). This is especially true when the competitors are gum and maple. 

The quality of wildlife habitat is generally enhanced 

if a few scattered or clumped pines remain in the 

stand throughout its tenure. Fifty years into the 

management period the stand profile might appear 

like the hardwood option (H) in figure 1. 

MANAGEMENT OPTIONS AT 50 YEARS 

P-PINE 0-OAK 

Figure I.- - Stand profiles of three management options at age 50. 

Pine stocking in the initial regeneration of these 

stands should be discouraged by a series of 

preplanned alterations in regeneration procedures. 

Included alterations are (1) minimize soil disturbance and exposure, (2) reduce or eliminate the 

pine seed source around the perimeter of the stand, 

(3) initiate site preparation during years of weak 
pine seed crops, (4) avoid small stand sizes that 

have a high percent of the area within the seeding 

distance of adjacent pines, and (5) delay site 

preparation treatments until lobtolly pine seed-inplace have germinated. Hardwood stocking of 

preferred species could be increased by (1) injecting undesirable hardwoods with herbicides either 

before or after logging, (2) enrichment plantings or 

direct seeding, and (3) retention of hardwood seed 

trees. 

Qptimized Timber Revenues 

Managing the loblolly pine from natural regeneration origin is an attractive financial option. With low 

initial investments and a high potential volume yield 

the loblolly pine will produce a high rate of return 

(ROR) in a 30 to 40 year investment period. Investors should make their own analyses and assumptions, but this option should produce ROR 

percentages in the high teens. 

In south Mississippi, pine sawtimber stumpage 

averages 3 to 4 times as high as the utility grade 

hardwood sawlogs this site will produce. Pulpwood 

stumpage differentials are about the same. Similar 

sites at age 50 can conservatively be expected to 

yield between 28-25 MBF per acre of pine sawdimber when the stand is thinned properly. Hardwood 

product volumes will average 60 to 70 percent less 

over the same period of time (figure 2). 

Estimated Empirical Volumes at Age 50 

Pine Volume 

Hardwood Volumm 

Pine PinelHardwood Hardwood 

Management Options 

Figure 2. - - Estimated empirical volumes at age 50. 

To apply this option to the two case-study stands, 

managers should thin from below early and often. 

The initial thinning could occur at age 15 and reoccur at age 20-22. Thinning objectives should be to 

retain 70 to 80 square feet of basal area in the 

largest and best pine stems and to move them into 

the sawtimber product class as soon as possible. 

Little regard should be given to saving or preventing 

damage to the hardwood stems during logging. 

Hardwoods are expected to fall farther behind into 

intermediate and suppressed crown classes as the 

pine grows to the full height of its site class potential. 

These are moderately high risk sites for Southern 

Pine Beetle because of the poor internal drainage of 

the soil and loblolly pines' inherent high susceptibility. To minimize losses to this pest, logging 

should occur during dry seasons when rutting and 

root damage will be less. Also, as always, mechanical damage to the pine boles should be avoided. 

Forest managers who favor high financial returns 

on these sites should at stand establishment encourage the regeneration of loblolly pine. This can 

be done by (1 ) timing the site preparation treatments to occur just before good to bumper loblolly 

seed crops, and (2) providing a receptive seedbed 

by exposing mineral soil. 

The Pine-Hardwood Option 

Forest managers desiring both high financial and 

wildlife yields should consider molding a mixture of 

pine and hardwood. It may be one of the few 

places where they can enjoy the "best d two 

worlds". To exercise this option, managers should 

(1 ) encourage the establishment of natural pine seedlings, and (2) carefully select species and levels of 

species groups to remove (and favor) in the first 3 

to 4 cleaninglthinning operations. 

CONCLUSIONS 

The dynamics of forest stands during establishment 

and subsequent growth periods provide forest 

managers with a variety of options. This is especially true on stream bottom sites when loblolly pine is 

a component. The preferred option should ideally 

be determined before the regeneration process 

begins. Managers should modify their practices to 

shape initial species composition. Ten to fifteen 

years and following after establishment the mixtures 

of species can be altered by thinnings and cleanings. 

LITERATURE CITED 

Baker, James 8.; Broadfoot, W.M. 1979. A practical field method of site evaluation for 

commercially important southern hardwoods. 

Gen. Tech. Rep. 50-26. U.S. Department of 

Agriculture, Forest Service, Southern Forest Experiment Station. 51 pp. 

Clatterbuck, W.H.; Hodges, J. D. 1988. Development of cherrybark oak and sweetgum in mixed, 

even-aged bottomland stands in central Mississippi, U.S.A. Canadian Journal of Forest Research, 

VOI. 18, NO. 1, pp 12-18. 
LOWER COASTAL PLAIN PINE-HARDWOOD STANDS: 

MANAGEMENT OF TWO DISTINCTLY DIFFERENT SITE 

WPES 

Donald J. Lipscomb and Thomas M. ~illiamsl 

. - Pine-hardwoods on the lower Coastal Plain occur on two distinct site types. The ridge 

pine-hardwood site type occurs on welt-drained soils near well deveioped drainage systems. On 

this type pines are associated with red oaks and water tables are more than 4 feet below the surface. Management of this site type will differ little from techniques used in the upper Coastal Plain 

or Piedmont. The flatland pine-hardwood site type occurs on poorly drained soils of lower elevation or on broad inter-stream divides. On this type pines are associated with sweetgum and blackgum and water tables seldom are deeper than 3 feet with saturated conditions occurring every 

year, Management of this site type will be hampered by limitations on heavy equipment, possible 

wetland regulations, and difficulty in using prescribed fire. 

INTRODUCTION 

South Carolina has, and will continue to have, a significant area of its forest in mixed pine-hardwood 

types (Baumann and others 1988). In 1978 South 

Carolina had 1.7 million acres in the oak-pine type 

with a significant portion being regenerated to pinehardwood (Knight arid McClure 1979). in 1979 

Knight and McClure forecasted a 57 percent increase in available hardwood cut for the coming 

thirty-year period. Baumann and others (1988) also 

point to an expected forty percent increase in the 

harvest of hardwood in the next thirty years. This increased hardwood harvesting reinforces the need 

to begin now to plan the management and wise use 

of all sites that grow hardwoods. 

Mixed pine-hardwood forests are generally treated 

under silvicultural recommendations for the group 

known as the oak-pine cover type (Burns 1983). In 

the oak-pine type upland oaks and other 

hardwoods comprise more than fifty percent of the 

stocking and pines the remainder. A number of 

drained soils. The latter site type may be incorporated into the type definition of some hardwoods, 

but in such a way that these pine-hardwood mixes 

become a part of the oak-pine type. For example, 

Sheffield (1 978) defines the oak-gum-cypress type 

as follows: "Bottomland forests in which tupelo, 

blackgum, sweetgum, oaks, or southern cypress, 

singly or in combination, comprise a plurality of the 

stocking, except where pines comprise 25 to 50 percent, in which case the stand would be classified 

oak-pine (common associates include cotronwosd, 

willow, ash, elm, hackberry, and maple.)". The 

sweetgum-yellow poplar (type 87) described by the 

Society of American Foresters similarly incorporates a possible pine component. 

These definitions include the flatland pinehardwoods along with the ridge pine-hardwoods as 

a transitional succession stage. The flatland site 

type is not separated from the oak-pine type for 

management considerations. 

cover types defined by the Society of American 

Foresters (Eyre 1980) are included in this general Regulatory agencies with jurisdiction over wetlands 

type. Longleaf Pine-Scrub Oak (type 71 ) and Loblol- are mapping flatland pine-hardwoods as palustrine, 

ly pine-hardwood (type 82) are most common in forested, broad-leaved deciduous (Cowardin and 

South Carolina. Both of these types are prominent others 1979). This site type would most logically fit 

in the lower Coastal Plains. into the "wetflat" definition in the "Best Management 

Practices for South Carolina's Forest Wetlands " 

The loblotly pine-hardwood (type 82) occupies two 

distinct sites in the lower Coastal Plain. The first 

site type is on moderately well- to well- drained soils 

on high topographic positions or near well 

developed drainages. The second site type is located on lower topographic positions or on broad 

inter-stream divides and has poorly- to very poorly- 

(S.C. Comm. of For. 1988). Because of the increasing emphasis on wetlands management practices, it 

will become necessary to distinguish these two site 

types in the Coastal Plain and consider them under 

separate management and silviculture assumptions. 

The purpose of this paper is to discuss the basic 

characteristics which distinguish these two site 

types and some possible differences in management considerations. 

 o ore st Director and Associate Professor, Belle W. 

Baruch Forest Science Institute, Clemson University, 

Georgetown, SC 
METHODS 

The study was conducted on Hobcaw Barony, locatd in the lower Coastal Plain near Georgetown, 

South Carolina. The 7,500 acre forested portion of 

the Barony was type mapped prior to an inventory 

in 1976. Pine-hardwood stands were classified Into 

ridge pine-hardwood and flatland pine-hardwod 

she types based on topographic positions. During 

1986 all pine-hardwood stands were re-inventoried 

using point sampllng with a 10 factor prism. A 10 

percent sample was attempted on each stand 

delineated. Twenty stands (tracts) containing 239 

sample points typed as ridge pine-hardwoods were 

processed using the Tennessee Valley Authority Inventory processor (TVAIP version 4.0). A unit summary showing total stems by species was used to 

develop a table representing all twenty tracts . 

Similarly 561 sample points were summarized from 

15 stands of the flatland pine-hardwood site type. 

The NAlP employs grouping of some species of 

lesser economic interest, but we feel the tables are 

pretty accurate indices of species associations and 

composition. These 35 stands, representing 69 perData to evaluate water table positions of the 

proposed site types were collected from a series of 

water fable wells located on the forest. A series of 

45 wells was installed into the water table aquifer in 

the summer of 1975. These wells consist of plastic 

or asphaited paper pipes inserted from 6 to 15 feet 

into the aquifer. All wells are open bottomed and 

screened throughout their length with lf4" holes. 

Water table elevation has been measured in each 

well weekly since July 1975. Seven wells fell in pinehardwood stands. One was located along a site 

type boundary but three wells were located in each 

site type (figure 1). 

Monthly average water table depths for each site 

type were determined by averaging depths in the 

three wells in each site type. For each month from 

1976 through 1988 weekly elevations were averaged 

for the three wells. Means and standard errors were 

calculated from the 12 or 15 depth readings for 

each month. These means and error estimates (expressed as 95 percent confidence intervals) are 

presented in figure 2. 

cent of the ridge pine-hardwood and 78 ~ercent of 

the flatland pine-hardwood type, were selected to RESULTS 

represent the greatest area with the smallest num- Ridge pine-hardwoods and flatland pine-hardwoods 

ber of stands since each stand required a separate are distinct site types on the South Carolina coast. 

computer run. Water table depth data clearly separate these two 

Figure 1 .-- Distribution of pine-hardwood types on 

Hobcaw Forest. Locations of measured wells and 

those for which records were averaged to determine water tables in pine-hardwood site types. 
site types. Water tables in the flatland pinehardwood type remained less than 4 feet below the 

surface for the entire 12 year record. In the ridge 

pine-hardwood type the water table seldom rose to 

within 5 feet of the surface. The water table in the 

ridge pine-hardwood stands was generafry 4 to 5 

feet deeper than in the flatland pine-hardwood 

stands at any time. Water tables in both types 

responded similarly to the balance of rainfall and 

evaporation with highest water tables in late winter 

and lowest in fall to early winter. 

Although timber species are similar there are distinct species in each type (table 1 and 2). Ridge 

pine-hardwood stands are predominately oak-pine 

species associations, however, loblolly pinehardwood types (SAF type 823 on poorly drained 

sites do not easily separate into the flatland pinehardwoods on the basis of species associations 

alone. Tables 1 and 2 show composition of stands 

from each site type combination in the lower South 

Carolina Coastal Plain. The species lists are similar 

and both fit SAF type 82, but the relative frequencies of the hardwood components must be examined to distinguish the sites. On the dry ridge 

pine-hardwood sites, fire and drainage appear to affeet species ifssoeiatirsrr sur\/iuai. 

Table 1 shows the flatland pine-hardwood stands 

with the gums and wet site oaks d~rninating the 

hardwood species component. Again the 

dominance of these fire-susceptible, wet site-adaptable species distinguishes the type from its ridge 

counterpart, but the difference is in stem count and 

basal area, and cannot be determined from the 

species association lists alone. 

The ridge pine-hardwood site type conforms with 

descriptions for the oak-pine type (Burns 1983) 

(table 2). It is found on moderately well- to welldrained soils with water tables ranging from 4 to 10 

feet below the surface (figure 2). It generally occurs 

at elevations greater than 10 feet above sea level 

and is found along banks and ridge? near well 

developed water courses. The depth of water table 

clearly distinguish this site. In these stands all 

microsites are available to all species and species 

distributions are primarily due to natural disturbance or management. 

The flatland pine-hardwood site type has similar 

species associations; however, the site is found in a 

different topographic position and is consistently 

wetter than its ridge pine-hardwood counterpart. 

Soils are pooriy- to very poorly-drained and the 

water table remains relatively shallow throughout 

the year (figure 2). This site type is usually found 

on broad flats located some distance from well 

developed stream courses. On this site pines are 

restricted to specific dry microsites. Hardwoods occupy all remaining areas with tittle disturbance due 

to fire. 

Table 1. Flatland Pine-~ardwoodl 

Species Group Trees /ftc2 Pct BA3 Pct 

Ash 

BlaCk gum 

Black oak 

Cypress 

Elm 

Hickory 

Holly 

LobloIiy pine 

Misc red oaks 

Misc yellow pines 

Post oak 

Red maple 

Southern red oak 

Sweet gum 

Water oak 

White oak 

Laurel oak 

Yellow poplar 

Longleaf pine 

Swamp chestnut oak 

Magnolia 

Misc hardwoods 

Sweet bay 

Persimmon 

Swamp white oak 

Fifteen representative stands, occupying 718 acres, were selected 

for the! flatland pine-hardwood site type; 561, 10 BAF point samples 

were recorded and then summarized as a TVAIP unit. 

Stems per acre of all trees 4 in. DBH and larger of the labeled 

species. 

Basal. area (ft2/acj of all trees 4 in. DBH and larger of the 

labeled species. 

Table 2. Ridge pine-~ardwood' 

Species Croup Trees/Ac2 Pct BA~ Pct 

Ash 

Black cherry 

Black gum 

Cypress 

Dogwood 

Eastern red cedar 

Hickory 

Holly 

Loblolly pine 

Misc hardwoods 

Misc red oaks 

Live oak 

Post oak 

Red maple 

Shortleaf pine 

Southern red oek 

$wee tgum 

Water oak 

White oak 

Laurel oak 

Yellow poplar 

Longleaf pine 

Totals 

Twenty representative stands, occupying 445 acres, were selected 

for the ridge pine-hardwood site type; 239, 10 BAF point samples 

were recorded and then swmarized as a TVAIP unit. 

Stems per acre of all trees 4 in. DBH and larger of the labeled 

species, 

' Basal area (ft2lac) of all trees 4 in. DBH and larger of the 

labeled species, 
c 1 'tRidge Pine-Hardwood 

Figure 2.-- Monthly mean water table elevations and 

95 percent confidence limits for wells located in will not carry fire during most years; thus, spot ignipine-hardwood site types. tion of the pine micro-sites will prove less effective 

and more costly than normal prescribed burning. 

MANAGEMENT IMPLICATIONS 

Some differences in management considerations become readily apparent when these two site types 

are separated. By most definitions the site type 

labeled flatland pine-hardwood will be a wetland 

(Cowardin and others 1979, S.C. For. Comm. 

1988). Stand conversion to pine plantation will be 

much more difficult on these poorly drained sites 

and may often involve a degree of site conversion 

by drainage. A close look at figure 1 reveals potential access difficulties for operations that require 

heavy equipment. There were only 3 years out of 13 

when equipment could have worked on the flatland 

pine hardwood sites monitored, if we assume a 

water table depth of 1.5 to 2 feet is required to 

avoid severe compaction and rutting. To further 

complicate this problem, removal of a significant 

portion of the timber will cause a rise in the summer 

and fall water table (Williams and Lipscomb 1981). 

Fire can readily be employed on the ridge-pinehardwood site type for a number of silivicultural objectives (Ferguson 1961 ; Sanders and others 1987; 

and Waldrop and others 1985). However, application of prescribed fire to flatland pine-hardwood site 

types will be very restricted. Stands on these sites 

The pine component in flatland pine-hardwood 

stands often provide economic motivation for 

management, especially where it approaches fifty 

percent of stand composition. However, the 

hardwood component is not usually composed of 

high quality or high value species and therefore 

does not justify costly stand improvement or harvesting operations (table 1). The ridge counterpart 

offers the same problem with relation to the 

hardwoods (table 2); however, it has more site available to favor the perpetuation of the pine component. Future markets may make management of 

the hardwood component more attractive and cost 

effect lve. 

RECOMMENDATIONS 

The flatland pine-hardwood site type will need to be 

distinguished in the development of pine-hardwood 

management prescriptions. The flatland pinehardwood sites are characterized by near saturated 

conditions for several months of each year. Management of this type may be restricted under wetlands 

regulations. Wet conditions will limit the use of 

heavy equipment and limit effectiveness of some 

herbicide treatments. Techniques to identify and 

map the flatland pine-hardwood sites will need to 
be developed for the Lower Coastal Plain. The initial 

differentiation of site types on Hobcaw was based 

on qualitative estimates of landscape position. The 

data on water table position indicates that field identification may be easily done by locating a water 

table near the ground surface. The relatively similar 

vegetation of the two types may limit mapping of 

the types by remote sensing techniques, although 

computerized geographic information systems may 

be useful in such mapping. The water table differences between the site types are quite distinct and will 

be reflected in soil series differences. A computerized mapping system can overlay maps of 

poorly drained soils series on a vegetation type 

map. The resulting union could distinguish flatland 

pine-hardwood site types. 

LITERATURE CITED 

Baumann, Jeff; Price, Debbie; Morris, Jennie. 

1988. South Carolina's Fourth Forest. South 

Carolina's Fourth Forest Committee. 25 p. 

Burns, Russel M. (Technical Compiler). 1983. Silvicultural Systems for the Major Forest Types of 

the United States. USDA Forest Service, Agricultural Handbook No. 445. 191 p. 

Cowardin, L. M.; Carter, V.; Golet, F.C.; Large, E.T. 

1979. Classification of wetlands and deep water 

habitats of the United States. USDI, Fish and 

Wildlife Service, FWSiOBS-79/31. 

Eyre, F. H. (ed). 1980. Forest cover types of the 

United States and Canada. Society of American 

Foresters, Washington, DC 148 p. 

Ferguson, E. R. 1961 . Effects of prescribed fires 

on understory stems in pine-hardwood stands of 

Texas. Journal of Forestry 59356-359. 

Knight, Herbert A.; McClure, Joe P. 1979. South 

Carolina's Forests. USDA, Forest Service 

Resource Bulletin; SE-51. Southeast Forest Experiment Station, Asheville, NC. 66 p. 

Sanders, D. L.; Van Lear, D.H.; Guynn, D.C. 1987. 

Prescribed burning in mature pine-hardwood 

stands - effects of hardwoods and small mammals. p. 93-86. In: D. R. Phillips (ed.); faroc. of 

the Fourth Biennial Southern Silvicultural 

Research Conference, 1986 Nov. 4-6, Atlanta, GA. 

USDA Forest Service. Southeastern Forest Experiment Station, General Technical Report. 

SE-42. 598 pp. 

South Carolina Forestry Commission. 1988. Best 

Management Practices for South Carolina's 

Forest Wetlands. SC Commission of Forestry, 

Columbia, SC 20p. 

Sheffield, Raymond M. 1978. Forest Statistics for 

South Carolina. USDA Forest Service Resource 

Bulletin; SE-50. Southeast Forest Experiment Station, Asheville, NC. 34 p. 

Waldrop, Thomas A.; Buckner, Edward R.; Muncy, 

Jack A. 1985. Cultural treatments in low-quality 

hardwood stands for wildlife and timber production. p. 493-500. In E. Shoulders, ed. 

Proceedings Third Biennial Southern Silvicultural 

Research Conference, Atlanta, GA. USDA Forest 

Service, General Technical Report. $0-54. 

Williams, Thomas M .; Lipscomb, Donald J. 1981. 

Water Table Rise After Cuning in Coastal Plain 

Soils. Southern Journal of Applied Forestry. 

5:46-48. 
POSTER ABSmCTS 

NITROGEN GAINS AND LOSSES ASSOCIATED WITH 

SITE-PREPARATION BURNING IN SOUTHERN 

PINE-HARDWOOD FORESTS 

Lindsay R. Boring, Joseph J. Hendricks, University of Georgia; and M. Boyd 

Edwards, Southeastern Forest Experiment Station 

ABSTRACT 

High-intensity site-preparation burning on Piedmont sites may result in excessive losses of forest 

floor organic matter and nitrogen. Nitrogen losses may range from 50-300 kg N ha" yr'l from burning logging slash. Few case studies have closely examined losses from burning forest floor organic 

matter, erosion of residual ash and litter, or rapid microbial transformation and leaching of residual 

organic nitrogen. Losses resulting from burning coarse woody debris (slash), which may serve as a 

substrate for free-living nitrogen-fixing bacteria, must also be considered. 

Nitrogen losses due to site-preparation burning may be extensive, but there are sources of replenishment to the site. Nitrogen fixation by free-living bacteria in the forest floor is generally < 3.7 kg N 

ha" yr-l. Atmospheric inputs of nitrogen may range from 5-1 2 kg N ham1 yr". 

One additional source of replacement is symbiotic nitrogen fixation by understory legumes, < 1 -1 0 

kg N ham1 yr-l, which are abundant in frequently burned forest ecosystems. These legumes generally deposit nitrogen-rich leaf litter to the forest floor. Substrate quality analyses indicate that this litter 

may have rapid to moderate decomposition and mineralization rates. 

All of these nitrogen inputs may be highly variable over space and time, and more detailed information on these processes is needed. Estimated nitrogen losses during and following intensive burning 

must be balanced by gains over the length of a forest rotation. 

LITERATURE CITED 

Abercrombie, J.A., Jr.; Sims, D.H. 1986. Fdl and burn for low-cost site preparation. Forest Farmer 

4611 4-1 7. 

Boring, L.R.; Swank, W.T.; Waide, J.B.; Henderson, G.S. 1988. Sources, fates, and impacts of 

nitrogen inputs to terrestrial ecosystems: review and synthesis. Biogeochemistry 6: 1 19-1 59. 

Hendricks, Joseph J. 1989. Nitrogen fixation and litter quality of understory legumes in a burned 

pine forest of the Georgia Piedmont. Athens: University of Georgia. 90 pp. Thesis. 

Van Lear, D.H.; Johnson, V.J. 1983. Effects of prescribed burning in the Southern Appalachian and 

upper Piedmont forests: a review. Department of Forestry, Forest Bulletin No. 36. Clemson, SC: 

Clemson University. 8 p. 

Van Lear, D.H.; Waldrop, T.A. 1987. Current practices and recent advances in prescribed burning. 

pp. 69-83. In: Carpenter, S. (ed.). Proceedings: Southern forestry symposium; 1985 November 1 9- 

21; Atlanta, GA. 
DOIELOPING FEEDBACK THINNING POLICIES FOR UNOIEN-AGED 

MANAGEMENT WITH STOCHASTIC PRICES 

Robert 6. Waight, Research Forester, USDA Forest Service, Southeastern Forest Experiment 

Station, Box 12254, Research Triangle Park, NC 27709. 

Abstract 

Two questions that this study begins to address are: (1) What are the effects of uncertain biofogical and economic parameters on the returns from uneven--aged management and (2) Is it possible to devise management strategies that mitigate the effects of these uncertainties? Most 

modeling studies that evaluate the efficiencies of alternative silvicultural systems use point estimates of financial performance and ignore the uncertainties in both biological and economic 

model parameters. Stochastic simulation has been used to study the effects of uncertain 

economic parameters on the performance of management systems in a range of timber types. 

Although stochastic simulation measures the impact of uncertainty on the performance of a 

given strategy, it does not devise management strategies that perform better in the face of 

parameter uncertainty. 

One way to mitigate the negative effects of uncertainty when analyzing uneven--aged management is to employ feedback thinning policies. A feedback thinning policy is a conditional set of 

actions where thinning intensity at each decision point is a function of the stand state at that 

point. Let x(t) be the stand state at the beginning of each time period t in which management action is considered. When future stumpage prices are uncertain, a flexible feedback thinning 

policy can be constructed by letting the number of trees harvested H(t) be a function of stand 

vat ue V [x(t)] : 

if V[x(t)] > b2 

otherwise 

where bl 2. 0.0 and b2 is unrestricted. Depending on the value of b3, the harvest level is either 

constant or an increasing function of stand value. When b3 = 0.0, H(t) = bl; a constant harvest is 

taken each period. When b3 = 1.0, H(t) = bl jjV[x(t)]-b2; the cut increases linearly with stand 

value. When b3 = 0.5, H(t) = bl {V[x(t)]-b2 ; the cut increases with stand value at a decreasing 

rate. Diameter class thinning rates are obtained by proportioning the total harvest among the 

diameter classes according to some thinning type rule (e.g., thin from above). The uneven--aged 

management problem involves determining optimal values for the feedback function parameters 

b~, b2, and bg. 

Using this feedback function, optimal thinning strategies are developed for an uneven-aged white 

fir stand in California. The planning horizon is 100 years, the cutting cycle is 20 years, and the 

objective is to maximize present value. With deterministic prices, constant cut and linear feedback thinning policies give illmast the same present value as the optimal (openloop) diameter-- 

class thinning regime. With stochastic prices, the optimal feedback thinning policy is an 

increasing, nonlinear function of stand value. Based on Monte Carlo simlulations, the nonlinear 

feedback thinning policy provides a greater expected return than do either the openloop or feedback thinning policies from deterministic optimization. These met hods are being extended to 

management problems involving mixed pine-hardwood stands in the South. 
WORKING WITH NATURE: PINE-HARDWOOD MIXTURES 

Jacqueline L. Haymond, Department of Forestry, Ciemson University and 

James A. Abercrombie, Jr., USDA Forest Service 

Sumter National Forest 

ABSTRACT 

This videotape describes a method of regenerating low-quality mixed pine-hardwood stands on 

medium sites to stands of higher quality trees through natural sprouting of hardwoods and enrichment planting of genetically improved pine seedlings. Sites are prepared using the fell-andburn technique developed by James A. Abercrombie. The method has worked well in the 

Ouachita Mountains of Arkansas and the Appalachian Mountains of South Carolina. The steps 

taken are: 

1. A suitable stand on a medium site is selected. 

2. The stand is clearcut. 

3. Some remaining trees are cut for firewood by local people. 

4. All residual stems are felled in late spring at 3/4 to full leafout using a chainsaw or brushcutter. 

5. The area is broadcast burned in mid-summer after nesting season. 

6, Improved pine seed!ings are interplanted among the hardwood stumps at wide spacing the 

following planting season. 

This method of regenerating pine-hardwood rnix-tures is being tested in the Piedmont regions sf 

South Carolina and Georgia. Many questions remain. Research is being conducted by the 

Pine-Hardwood Silviculture Research Work Unit of the USDA Forest Service. 

This videotape runs 15 minutes and 45 seconds. A copy may be obtained by sending a blank 

tape (1/2 inch, 20-minute VHS) to: Dr. Jacqueline L. Haymond, Department of Forestry, Clemson University, Clemson, SC 29634. 
NUTRIENT RESPONSE TO OVERSTORY REMOVAL AND WINTER 

PRESCRIBED FIRE VERSUS CLEARCUiTlNG AND SUMMER SITE 

PREP BURNS IN OKLAHOMA OUACHITA MOUNTAINS 

RONALD E. MASTERS, OkSa homa Department of Wildlife Conservation, 1801 North Lincoln 

Blvd., Oklahoma City, Oklahoma 73105 

ABSTRACT 

nt response of elmleaf goldenrod ( stiffleaf sunflower 

, greenbriar (Smilax bona-nox), wi wpallina), and wi 

various levels of overstory removal and winter prescribed fire versus clearcutting and summer site preparation burn was studied in the Ouachita Mountains of eastern Oklahoma. Differences (p < 0.10) due to treatments were noted in percent crude protein, calcium, phosphorous, 

Ca:P ratio, ash, magnesium and potassium. Acid detergent fiber and total digestible nutrients did 

reatments. Nutrient levels varied by treatment and among species of preferred 

virginianug) foods. Early fall forage nutrient levels were correlated with overstory basal area, canopy closure, and to a lesser extent presence or absence of fire. Crude 

protein and phosphorous values decreased as basal area and overstory cover increased. Conversely, calcium and Ca: P ratios increased as basal area and overstory cover increased. Winter 

rough reduction burns elevated phosphorous, magnesium and potassium values and depressed 

crude protein and calcium levels, but not significantly in most cases. Overstory removal and fire 

together increased crude protein, phosphorous, and magnesium, while ash, calcium and Ca:P 

ratios were reduced. Not all parameters of all forages showed significant differences due to treatments. Overstory removal by harvesting shortleaf pine (Pin* echinata) , selectively inject ing 

hardwoods and winter prescribed burning resulted in greater nutrient concentrations and more 

differences across the range of nutrient parameters and forages than other treatments. Mean 

nutrient levels of forages from the overstory removal and winter prescribed burn treatment were 

not in most cases significantly different from the clearcut and summer site prep burn treatment. 

The uncut unburned control had the lowest nutrient response of all treatments. Findings aid in 

developing wildlife andorest management techniques that maximize early fall nutrient levels in 

preferred deer foods. 
A GR H PROJECTION SYS'TEM FOR MIXE PECIES STANDS 

Ralph S. MeIdahi, Roger K. Botton, School of Forestry, Auburn University; and 

Timothy R. Bottenfield, Alabama Agricultural Experiment Station, Auburn, AL. 

ABSTRACT 

Efforts have been undeway at Auburn University since the early 1980's to develop models that 

predict tree growth in the South. The general direction of this research is to develop a growth 

projection system capable of predicting the development of major forest types throughout the 

South. This work has concentrated on model building, and has relied on the TWIGS projection 

system for the computer framework for model implementation. Recent efforts have concentrated 

on two major projects. The first is a growth projection system based on the state of Georgia 

(GATWIGS). This system is currently under validation and verification. The second project is to 

improve on GATWIGS and build a much broader system (for Alabama, Georgia, and South 

Carolina) which can be used throughout much of the Southeast (SET). These projection systems are distance-independent individual tree models, which were developed from U. S. Forest 

Service survey data. Crown ratio, total height, diameter increment, and survival models have 

been developed for clusters of observations based on physiographic region, species, and forest 

type. A brief description of the resource and data base is followed by a discussion of model 

development. Both of these products will be available through the Forest Resources Systems Institute upon their completion. 
PHOTOS FOR ESTIMATING RESIDUE LOADING BEFORE AND AFTER 

BURNING IN SOUTHERN APPALACHIAN MIXED PINE-HARDWOOD 

STANDS 

Bradford M. Sanders and David ti. Van Lear, Clemson University, Department of Forestry, 

Clemson, South Carolina 

ABSTRACT 

Harvested stands in the Southern Appalachians contain large volumes of woody debris following 

spring clearfelling of nonmerchantable, residual trees. Knowledge of the fuel loading, distri bution, and characteristics of this residue is needed to effectively prescribe fuel treatments for site 

preparation and reforestation. The planar intersect technique was used to estimate fuel loadings 

before and after high-intensity summer boradcast burning. Weight of woody slash, litter, duff, 

and live fuels was estimated. A photo series describing the range of fuel loadings on clearcut 

sites in the Southern Appalachians was developed by establishing eight triangular photo plots in 

areas with slash fuel loadings of 16, 18, 22, 28, 31, 33, 43, and 52 dry tons per acre. Burning 

reduced slash fuel an average of 52 percent. Woody slash less than 3.0 inches in diameter was 

reduced an average of 78 percent by burning, thereby facilitating planting operations and reducing the potential for unplanned ignitions. 
OF FIRE ON TABLE MOUNTAIN PINE COMMUNITIES 

Greg Sanders and Ed ward Buckner, The University of Tennessee, Knoxville 

ABSTRACT 

In a study still in progress on Bote Mountain in the Great Smoky Mountains National Park, 

regeneration of table mountain pine ( Lam.) following an April 1986 fire is most 

successful where fire intensities were high. The high intensities most successfully produced the 

conditions needed for table mountain pine regeneration: opening of serotinous cones, mineral 

soil seedbed, and opening of the stand to full sunlight. 

Of the 20 plots 0.4 hectare in size, seven were located where fire intensities were low (surface fire 

only), six where intensities were moderate (surface fire with some scorching and torching of individual trees), and seven where intensities were high (crown fire). Within each plot, 64 .25 sq.m 

subplots were sampled (1 280 total) in which the depth of residual organic matter and the number of table mountain pine seedlings germinating since the fire were recorded. 

A total of 366 table mountain pine seedlings were counted in the 1280 subplots for an overall density of 11,437.5 seedlingsiha. In the low fire intensity plots, only 14 seedlings were counted for a 

density of 1250/ha. In the moderate intensity areas, the density was 15,312/haI and in the high 

intensity areas, the density was 18,304/ha. 

Of the 366 seedlings recorded, 276 (75.4%) were found growing where the organic matter depth 

was less than 1 cm. Of the subplots sampled with less than 1 cm of residual organic matter, 198 

of 494 (40.0%) contained at least one table mountain pine seedling. The occurrence on subplots 

with residual organic matter of 1-5 cm was 98.1% (73 of 404), and 8.7% (2 of 282) where the organic matter was 6-10 cm deep. There was no occurrence of seedlings on any of the 99 subplots with organic matter depths greater than 10 cm. 

Current indications show that serotinous cones were opened by the heat in the moderate and 

high intensity areas, but there was less residual organic matter (i.e., more mineral soil exposed) 

in the high intensity areas. Of the subplots sampled in the high intensity areas, 61.9% had less 

than 1 em of residual organic matter (i.e., exposed mineral soil). In the moderate intensity areas, 

the rate was 33.6%, and in the low intensity areas, only 19.9%. 

Expected completion date on the project is September, 1989. 
EARLY REGENERAION RESPONSE IN A NORTH CAROLINA 

PIEDMONT MIXED PINE-HARDWOOD STAND 

Peter C. Steponkus, North Carolina State University 

ABSTRACT 

In order to predict the number and distribution of both the pine and hardwood component in 

mixed stands, and the subsequent pine and hardwood basal areas from which stand projections 

can be made, a long term study is being installed to determine initial stand composition based 

on composition of the prior stand, the composition of harvest residuals, the method of regeneration and site preparation, and site type and quality. 

The study was designed as a randomized complete block for plot layout with a 2 by 2 by 2 factorial design. Two harvest treatments, two site preparation treatments, and two pine regeneration treatments are used in the study. The two harvest treatments are clearcutting and a 

commercial clearcut where only merchantable stems will be removed. The site preparation treatments are with and without preharvest burning. The regeneration treatments will be planting 

loblolly pine at a 15 by 15 foot spacing and seed-in-place. Each replication consists of eight, 1 

acre treatment plots surrounding a centered 114 acre square measurement subplot. Each subplot is divided using a 4 by 4 grid to create 16 contiguous quadrats/subplot. A preharvest inventory of all trees 1.0 inches dbh and a milacre sample of advanced reproduction is made on each 

of the quadrats. A 100 percent inventory of regeneration will be made one and two years after 

harvest, and at longer intervals thereafter. Greig-Smith's (1 964) blocked quadrat variance (BQV) 

procedures will be used to determine spatial distribution of initial stand parameters and the subsequent regenera"clsn response. 

Two replications of the study were installed during 1988 in Chatham County, North Carolina. 

Four to six replications will be installed during 1989 at other North Carolina Piedmont locations. 

LITERATURE CITED 

Greig-Smith, P. 1964. Quantitative plant ecology. 2nd ed. Butterworths, London. 
APPENDIXES 

APPENDIX I -- REGISTRATION LIST 

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ROUTE 9 

BENTON, TN 37307 FREDDIE M. DIXON 

DEPT. OF BIOLOGY 

UNIV, OF DIST. COLUMBIA 

WASHINGTON, DC 20008 

LAURIE A. FENWOOD 

USDA FOREST SERVICE 

508 OAK ST. 

GAINESVILLE, GA 30501 

LEE CROMLEY 

TREEWRIGHT, INC. 

4467 ALLGOOD SPRINGS DR. 

STONE MOUNTAIN, GA 30083 ROBERT A. DOUGEERTY 

TN WILDL, RES. AGENCY 

P.O. BOX 92 

WAVERLY, TN 37185 

CARLYLE FRANKLIN 

NC STATE UNIVERSITY 

103 ENTERPRISE ST,, 

SUITE 209 

RALEIGH, NC 27607 

WILLIAf4 R. CROSS 

DIV. OF NATURAL RESOURCES 

MARINE CORPS BASE 

QUANTICO, VA 22134 THOMAS W. DOYLE 

8717 KINGSRIDGE 

GEMLB R, CROW KNOXVILLE, TN 37923 

WESTVACO CFM 

431 W. WIN ST. 

COVINGTON, VA 24426 

GEORGE A. FREELAND 

5119 WINTER PARK DRIVE 

ROANOKE, VA 24019 

ANTHONY DURKAS 

508 OAK ST., NW 

GAINESVILLE, GA 30501 

WILLIAM J. CULPEPPER 

USDA FOREST SERVICE 

$ SLOAN RD 

FRANKLIN, NC 28734 

THOMAS C. FRISTOE 

STONE CONTAINER CORP. 

14 S. NEWTON ST. 

CLAXTON, GA 30417 
BRUCE C. FRIZZELL 

DIV. OF NA-L RESOURCES 

INE CORPS BASE 

QUANTICO, VA 22134 

ROBERT G. HAIGHT 

SEFES 

BOX 12254 

RESMRCH TRIANGLE PAW,, 

NC 27709 

SAM HOPKINS 

GULF STATES PAPER CORP, 

P. 0. BOX 3199 

17JSCALOOSA, AL 35404 

DONN GEISINGER 

DEPARTMENT OF FORESTRY 

CLEMSON UNIVERSITY 

CLmSON, SC 29631 

CARRY F. HOUF 

1108 MIMOSA 

ROLLA, MO 65401 

CHARLES WRDEN 

SAF 

5400 GROSVENOR LANE 

BETHESDA, MD 20814 ROBBIE HOWELL 

RT, 2, BOX 290 

MANTACHIE, MS 38855 

JIM GENT 

UNION CAMP, 

WOODMNDS DIV. 

P.0. BOX 1391 

SAVMNAH, GA 31402 

THOMAS HATLEY 

418 ASWORTH ROAD 

CHARLOTTE, NC 28594 MICHAEL B. HUDDLESTON 

TENNESSEE DIV. FORESTRY 

P, 0. BOX 100 

BURNS, TN 37029 

CARL HA?JSER 

P. 0. BOX 180 

JEFFERSON CITY, MO 65102 

KURT W. GOTTSCWALK 

NEFES 

P. 0. BOX 4360 

MORGANTOWN, WV 26505 

GEORGE HURST 

DEPT. WILDL. & FISHERIES 

MISSISSIPPI STATE UNIV. 

MISSISSIPPI STATE, MS 

JACKIE HAYMOND 

DEPARTMENT OF FORESTRY 

CLEMSON UNIVERSITY 

CLEMSON, SC 29631 

JEFF A, GRAVES 

STONE CONTAINER CORP. 

P. 0. BOX 1449 

STATESBBRB, GA 48458 

JIM HYLAND 

ALABAMA FOR. COMMISSION 

513 MDISON AVE. 

MONTGOMERY, AL 36107 

JAMES D. HAYWOOD 

USDA FOREST SERVICE 

2500 SHREVEPORT HIGHWAY 

PINEVILLE, LA 71360 

SKIP GRIEP 

P.O. BOX 2252 

ROANOKE, VA 24009 HOLLIS ISHEE 

RT. 3, BOX 138 

GRENADA, MS 38901 

JERRY HENDERSON 

USDA FOREST SERVICE 

9. 0. BOX 2227 

COLUMBIA, SC 29202 

CURT GRIFFITH 

USDA FOREST SERVICE 

1765 HIGHLAND AVE. 

MONTGOMERY, AL 36107 

TIM IVEY 

P. 0. BOX 807 

JOE HENDRICKS UNION, SC 29379 

1907 S. MILLEDGE AVE. 

APT. H-10 

ATHENS, GA 30605 

RICHARD GUILLORY 

CHAMPION INT. CORP. 

2157 GABRIEL DRIVE 

ORANGE PARK, FL 32073 

LARRY G. JERVIS 

N C STATE UNIVERSITY 

BOX 8002 

TODD E. HEPP RALEIGH, NC 27695 

TVA 

DIV. OF LAND & ECON. RES. 

NORRIS, TN 37828 

DAVID GUYNN 

DEPARTMENT OF FORESTRY 

CLEMSON UNIVERSITY 

CLEMSON, SC 29631 

JAMES E . JOHNSON 

VPI & su 

ARTHUR NINTON BUCKSBURG, VA 24061 

SCOTT PAPER COMPANY 

P.0, BOX 869 

WAYNESBORO, MS 39367 

WILLIAM L. HAFLEY 

BOX 8002, DEPT. FORESTRY 

N. C. STATE UNIVERSITY 

RALEIGH, NC 27695 

RHETT JOHNSON 

RT. 7, BOX 131 

ANDALUSIA, AL 36420 

ALAN HOLDITCH 

213 MAGNOLIA TRAIL 

BRANDON, MS 39042 

BILL JONES 

MONTGOMERY, AE 36104 
ROBERT J. LENTZ 

USDA FOREST SERVICE 

1720 PEACHTREE RD., 

ATUNTA, GA 30367 

TOM MARTIN 

700 N. TRYON ST. 

CHARLOTTE, NC 28202-2222 

ROBERT H. JONES 

SAVANNAH RIVER ECOL. LAB 

DMWER E 

AIKEN, SC 29801 

RON MASTERS 

OK DEPT. WILDL, CONSER. 

1605 E. OSAGE 

MCALESTER, OK 74501 

118 NEWINS-ZIEGLER HALL 

UNIVERSITY OF FLORIDA 

GAINESVILLE, FL 32611 

BRUCE D. LEOPOLD 

DEPT. WILDL. & FISHERIES 

DMWER LW 

MISSISSIPPI STATE, MS 

DOUGUSS W. MCCONNELL I1 

145 CLEMSON ST. 

CLEMSON, SC 29631 

DONALD J, LIPSCOMB 

BARUCH INSTITUTE 

P.0, BOX 596 

GEORGETOWN, SC 29442 

STEVE JONES 

DEPARTMENT OF FORESTRY 

CLEMSON UNIVERSITY 

CLEMSON, SC 29631 CWARLES E. MCGEE 

DEPT. FOR. WILDL. & FISH. 

UNIVERSITY OF TENNESSEE 

KNOXVILLE, TN 37901 

JOHN W. LITTLE 

S.C. FORESTRY COMMISSION 

BOX 453 

WALWALLA, SC 29691 

JOHN F. KELLEY 

USDA FOREST SERVICE 

P.O. BOX 906 

STARKVILLE, MS 37959 DAVID W. MCGREW 

USDA FOREST SERVICE 

P.O. BOX 128 

HOT SPRINGS, NC 28743 

TED KERPEZ 

DEPT. OF FORESTRY 

VPI&SU 

BLACKSBURG, VA 24061 

F. THOMAS LLOYD 

USDA FOREST SERVICE 

CLEMSON UNIVERSITY 

CLEMSON, SC 29631 JIM MCMINN 

FORESTRY SCIENCES LAB 

CARLTON ST. 

ATHENS, GA 30602 

SUSAN LOEB 

USDA FOREST SERVICE 

CLEMSON UNIVERSITY 

CLEMSON, SC 29631 

GINGER B. KOGELSCHATZ 

FOREST INVESTMENTS ASSOC 

5605 GLENRIDGE DR., 

SUITE 710 

ATLANTA, GA 30087 

RALPH MELDAHL 

SCHOOL OF FORESTRY 

108 SMITH HALL 

AUBURN UNIV., AL 36849 

NELSON S. LOFTUS, JR. 

9619 COUNSELLOR DRIVE 

VIENNA, VA 22181 

ERIC KURZEJESKI 

1110 S. COLLEGE AVE. 

COLUMBIA, MO 65203 DENNIS MENGAL 

N.C. STATE UNIVERSITY 

DEPT. OF FORESTRY 

RALEIGH, NC 27695 

PAUL G. LUCUS 

SCOTT PAPER COMPAW 

P.O. BOX 869 

WAYNESBORO, MS 39367 

H. ALAN LAMB 

STONE CONTAINER CORP. 

P. 0. BOX 1449 

STATESBORO, GA 30458 JOE MILLS 

S C FORESTRY COMMISSION 

P. 0. BOX 21707 

COLUMBIA, SC 29221 

DON LUENSER 

OAKDALE VO - TECH 

P. 0. DRAWER EM 

OAKDALE, LA 71463 

AL LAMBERT 

JIM THOWS FORESTRY 

P.0, BOX 974 

PAT MINOGUE 

SCHOOL OF FORESTRY 

108 SMITH HALL 

AUBURN UNIV., AL 36849 

WILLIAM G, LUPPOLD 

USDA FOREST SERVICE 

ROUTE 2, BOX 562-B 

PRINCTON, W 24740 

DARYL S. LAWSON 

WOODLAND SERVICES 60. 

727 UPCREEK ROAD 

NEW MRKET, AL 35761 MICKAEL E. MONTGOMERY 

USDA FOREST SERVICE 

51 MILL POND RD. 

DEN, CT 06514 

CKARLES J. MALEU 

MILLIKEN AND COMPANY 

P 0 BOX 1926 M 116 

SPARTANBURG, SC 20304 
W, KEITH MOSER 

420 EAST 54TH ST. 

MElJ YORK, NY 11220 

WALT PENN 

WESTVACO 

P, 0. BOX 458 

WICKLIFFE, KY 42087 

GREG RUARK 

USDA FOREST SERVICE 

P.0, BOX 12254 

RES, TRIANGLE PARK, NC 

PAUL A. mRPHY 

USDA FOREST SERVICE 

P.O. BOX 3516 

MONTICELLO, AR 71655 

ALAN E, PIGG 

USDA FOREST SERVICE 

1720 PEACHTREE RD., NFJ 

ATLANTA, GA 30367 

BRADFORD M. SANDERS 

DEPARTMENT OF FORESTRY 

CLEMSON mIVERSITY 

CLMSON, SC 29631 

RICK MUERS 

PURDUE UNIVERSITY 

RT. I, BOX 264-B 

DUBOIS, IN 47527 

HOWARD POITEVINT 

U.S. FISH AND WILDL SERV 

75 SPRING ST., SW 

ATLANTA, GA 30303 

GREG SANDERS 

UNIVERSE= OF TENNESSEE 

DEPT. FOR. WILDL. & FISH. 

KNOWLLLE, TN 37901-1071 

LARRY R. NELSON 

DEPARTMENT OF FORESTRY 

CLEMSON UNIVERSITY 

CLEMSON, SC 29634-1003 

SKIPPY REEVES 

U.S. FISH AND WILDL SERV 

75 SPRING ST., SW 

ATLANTA, GA 30303 

PHILLIP SASNETT 

GULF STATES PAPER CORP, 

P.O. BOX 3199 

TUSCALOOSA, A% 35S04 

JOHN E. NEWUND 

MEAD COATED BOARD, INC. 

RT. I, BOX 19 

WAVERLY, AL 36879 

JACK REICHERT 

USDA FOREST SERVICE 

WIGHUND AVE. 

MONTGOMERY, AL 36107 

BILL SEADER 

FEDERAL PAPER BOARD GO, 

B. 0, BOX I425 

AUGUSTA, GA 30913 

HEATHER NEWMARKER 

WESWACO CFM 

17 N, MNBOLPH ST. 

LEXINGTON, VA 24450 

DICK RIGHTMYER 

USDA FOREST SERVICE 

508 OAK ST, NW 

GAINESVILLE, GA 30501 

KENT SEGARS 

I?, 6, BOX 168 

NIARTSVILLE, SC 29550 

LARRY NIX 

DEPARTMENT OF FORESTRY 

CLEMSON UNIVERSITY 

CLEMSON, SC 29631 

SCOTT SIQALLENBERGER 

WESTVAGO 

RT. 1, BOX 3540 

ROCKY MOUNT, VA 24151 

JOEL ROBERTSON 

CHAMPION INTERNATIONAL 

P. 0. BOX 686 

LUMPKIN, GA 31815 

WIB OWEN 

N.C. WILDL. RES. COMM. 

512 NORTH SALISBURY ST. 

RALEIGH, NC 27611 

UYMOND H. SHEFFIELD 

USDA FOREST SERVICE 

P.0, BOX 2680 

ASMEVILLE, NC 28802 

TOM D. ROBINSON 

SCOTT PAPER COMPANY 

P.O. BOX 869 

WAYNESBORO, MS 39367 

DALE C. PANCAKE, JR. 

RT. 7, BOX 131 

ANDALUSIA, AL 36420 

RICWARD B. SHELFER 

USDA FOREST SERVICE 

308 WEXWOOD RB, 

COLUMBIA, SC 29210 

KIM F. ROHR 

WESTVACO CORP. 

P.O. BOX 166 

ANDREW PARKER BETHEL SPRINGS, TN 38315 

BURKE FORESTRY 

MORGANTON, NC 28655 

MIGWEL G, SHELTON 

SOFES 

P, 0, BOX 3516 

MONTLCELLB, AW 71655 

DARRELL W, ROSS 

DEPARTMENT OF ENTOMOLOGY 

UNIVERSITY OF GEORGIA 

S L. PATRICK ATHENS, GA 30602 

404 EAST MAIN 

PERRY, FL 32347 

DEAN SIMON 

N.C, WILD% RES, COM, 

512 NORTH SALISBURY ST. 

MLEIGW, bJG 2761% 

JENNIFER ROUGH 

PROCTOR AND GAMBLE 

P.O. BOX 238 

OGLETHORPE, GA 31068 
DANIEL H. SIMS 

USDA FOREST SERVICE 

1720 PEACHTREE RD., NW 

ATLSINTA, GA 30244 

JOHW SIMS 

MILLIKEN & CO. 

BOX 1926, M-116 

SPARTANBURG, SC 29304 

GLENDON W. SMALLEY 

GLENMARY FARM 

RABBIT RUN LANE, RT 1 

SEWANEE, TN 37375 

DAVID WM. SMITH 

228 CHEATHAM HALL 

VPI & SU 

BLACKSBURG, VA 24061 

GEORGE SMITH 

N.C. WILDL. RES. COW. 

512 NORTH SALISBURY ST. 

RALEIGH, NC 27611 

0. D. SMITH, JR. 

OZARK NATIONAL FOREST 

7 CEDARWOOD COURT 

RUSSELLVILLE, AR 72801 

ROBERT SMITH 

SCHOOL OF FOREST RES. 

UNIVERSITY OF GEORGIA 

ATHENS, GA 30602 

WALT SMITH 

USDA FOREST SERVICE 

240 ST. JOHNS ST. 

ARDEN, NC 28704 

WARING SMITH 

216 HUNTERDALE RD. 

mNKLIN, VA 23851 

WILLIAM D. SMITH 

BOX 8002, DEPT. FORESTRY 

N. C. STATE UNIVERSITY 

RALEIGH, NC 27695 

MARVIN W. SPEARMAN 

S.C. FORESTRY COMNISSION 

P.O. BOX 21707 

COLUMBIA, SC 29221 

KLAUS STEINBECK 

THE UNIVERSITY OF GEORGIA 

SCHOOL OF FOREST RES. 

ATHENS, GA 30602 

PETER STEPENKOS 

NC STATE UNIVERSITY 

BOX 8002 

RALEIGH, NC 27695-8002 

OSCAR M. STEWART 

USDA FOREST SERVICE 

P.O. BOX 2227 

COLUMBIA, SC 29202 

HUGH STILL 

1638 ISSAQUEENA DRIVE 

SENECA, SC 29678 

MIKE TARAS 

DEPARTMENT OF FORESTRY 

CLENSON UNIVERSITY 

CLEMSON, SC 29631 

JACK R. TAYLOR 

USDA FOREST SERVICE 

P.O. BOX 278 

DOUBLE SPRINGS, AL 35553 

KEVIN R. TAYLOR 

P. 0. BOX 342 

CENTRE, AL 35960 

ROBERT TAYLOR 

BANKHEAD NATIONAL FOREST 

P. 0. BOX 278 

DOUBLE SPRINGS, AL 35553 

ROBERT M. TAYLOR 

18 ROCHELLE ST. 

BRANDON, MS 39042 

RONALD E. THILL 

USDA FOREST SERVICE 

BOX 7600, S.F.A. STATION 

NACOGDOCHES, TX 75962 

JIM THOMAS 

P. 0. BOX 974 

SELMA, AL 36702 

MARK W. THOMAS 

ETSRC UNIV. OF MO. 

5450 S. SINCLAIR RD. 

COLUMBIA, MO 65203 

JOHN TILEY 

GULF STATES PAPER CORP. 

P.O. BOX 3199 

TUSCALOOSA, AL 35404 

RUSS TITUS 

BOX 509 

ROLLA, MO 65401 

DON TOMCZAK 

1720 PEACHTREE RD., NW 

SUITE 846 N 

ATLANTA, GA 30367 

THOMAS TREMBATH 

STONE CONTAINER CORP. 

412 N. CLARK ST. 

CLAXTON, GA 30417 

RONALD E. TRUE 

AL RIVER WOODLANDS, INC. 

P.O. BOX 99 

PERDUE HILL, AL 36470 

MARK TWERY 

NEFES 

P. 0. BOX 4360 

MORGANTOWN, WV 26505 

DAVID VAN LEAR 

DEPARTMENT OF FORESTRY 

CLEMSON UNIVERSITY 

CLEMSON, SC 29631 

CHARLES VAN SICKLE 

USDA FOREST SERVICE 

200 WEAVER BLVD. 

ASHEVILLE, NC 28802 

THOMAS A. WALDROP 

USDA FOREST SERVICE 

CLEMSON UNIVERSITY 

CLEMSON, SC 29631 

JIMMY WALKER 

USDA FOREST SERVICE 

1720 PEACHTREE RD., NW 

ATLANTA, GA 30367 
WINSTON WEST 

GEORGIA FORESTRY COMM. 

3005 ATLANTA HIGWAY 

GAINESVILLE, GA 30501 

BETH WHITE 

DEPARTMENT OF FORESTRY 

CLEMSON UNIVERSITY 

CLNSON, SC 29631 

DAVID WHITE 

USDA FOREST SERVICE 

CLEMSON UNIVERSITY 

CLEMSON, SC 29634-1003 

DAVID J. WHITE 

1718 PEACHTREE ST., NW 

SUITE 592 

ATLANTA, GA 30309 

ED WHITE 

PROCTOR AND GAMBLE 

P.0, BOX 238 

OGLETHORPE, GA 31068 

LES WHITMORE 

USDA FOREST SERVICE 

P.O. BOX 96090 

WASH., D.C. 20090-6090 

T. BENTLY WIGLEY 

DEPT. OF FOREST RESOURCES 

UNIVERSITY OF ARKANSAS 

MONTICELLO, AR 71655 

SCOTT WILKINSON 

OZARK NATIONAL FOREST 

P. 0. BOX 190 

CLARKSVILLE, AR 72830 

THOMAS M. WILLIAMS 

BAURCH INSTITUTE 

P.O. BOX 596 

GEORGETOWN, SC 29442 

SHEPARD M. ZEDAKER 

228 CHEATW HALL 

VPI & SU 

BUCKSBURG, VA 24061 

BRUCE ZUTTER 

SCHOOL OF FORESTRY 

108 SMITH HALL 

AUBURN UNIV., AL 36849 

APPENDIX I1 -- ALPHABETICAL LIST OF AUTHORS 

Abercrombie, James A., Jr. 75, 

Adams, John C. 

Baker, James B. 

Baumann, David P. 

Bechtold, William A. 

Berisford, C. Wayne 

Birch, Thomas W. 

Bolton, Roger K. 

Boring, Lindsay R. 

Bottenfield, Timothy R. 

Buckner, Edward 27, 

Cain, Michael D. 

Clatterbuck, Wayne K. 

Cooper, Arthur W. 

Cunningham, Robert J. 

Cutler, James D. 

Dennington, Roger W. 

Dierauf, T. A. 

Edwards, M. Boyd, Jr. 

Farrar, Robert M., Jr. 173, 

Farrish, Kenneth W. 

Franklin, E. Carlyle 

Fredericksen, T. S. 

Garner, Michael E. 

Geisinger, Donn R. 

Gottschalk, Kurt W. 

Hafley, W. L. 

Haight, Robert G. 

Hauser, Carl 

Haymond, Jacqueline L. 91 , 

Haywood, James D, 

Hendricks, Joseph J. 

Hepp, Todd E. 

Hurst, George A. 

Ince, Peter J. 

Jones, Steven M. 64, 

Kapeluck, Peter R. 

Kelly, John F. 

Kerpez, Theodore A. 

Kreh, R. E. 

Leatherberry, Earl C. 

Page 

Leduc, Daniel J. 

Lennartz, Michael R. 

Lentz, Robert J. 

Leopold, Bruce D. 

Lipscomb, Donald J. 

Lloyd, F. Thomas 75, 

Loeb, Susan C. 

Luppold, William G. 

Masters, Ronald E. 

McGee, Charles E. 

McManus, Michael L. 

McMinn, James W. 

McWilliams, William H. 

Meldahl, Ralph S. 

Montgomery, Michael E. 

Murphy, Paul A. 173, 

Nix, Lawrence E. 

Perkins, Carroll J. 

Ruark, Gregory A. 

Ruckelshaus, Thomas F. 

Sanders, Bradford M. 

Sanders, Greg 

Sheffield, Raymond M. 

Sims, Daniel H. 

Smalley, Glendon W. 

Smith, D. Wm. 

Smith, W. D. 

Stauffer, Dean F. 

Steponkus, Peter C. 

Still, Hugh R., Jr. 

Toliver, John R. 

Twery , Mark J . Van Lear, David H. 83, 91, 

Waldrop, Thomas A. 75, 

Warren, Randall C. 

Weaver, Garnet H. 

Wigley, T. Bently 

Willett, R. Larry 131, 

Williams, Thomas M. 

Zahner, Robert 

Zedaker, S. M. 

Page 

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