United States

Department of 

Agriculture

Forest Service

Northeastern 

Research Station

General Technical

Report NE-342

Proceedings of the Conference 

on Diameter-Limit Cutting 

in Northeastern Forests
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The findings and conclusions of each article in this publication are those of the individual 

author(s) and do not necessarily represent the views of the U.S. Department of Agriculture 

or the Forest Service. All articles were received in digital format and were edited for uniform 

type and style. Each author is responsible for the accuracy and content of his or her paper.

Manuscript received for publication 2 February 2006

Cover Photo

Diameter-limit cutting in a northern conifer stand.
Proceedings of the Conference 

on Diameter-Limit Cutting 

in Northeastern Forests

May 23-24, 2005

University of Massachusetts

Compiled and edited by:

Laura S. Kenefic

USDA Forest Service

and

Ralph D. Nyland

State University of New York

Sponsored by:

UMass Extension

University of Massachusetts, Department of natural Resources Conservation

State University of New York, College of Environmental Science and Forestry

USDA Forest Service, Northeastern Research Station

Society of American Foresters, Yankee Division

Published by:

USDA Forest Service, Northeastern Research Station
Contents

Facilitating a Dialogue About Diameter-Limit Cutting ...............................................1

Laura S. Kenefic and Ralph D. Nyland

Historical Perspective on Diameter-Limit Cutting in Northeastern Forests..................3

Matthew J. Kelty and Anthony W. D’Amato

Diameter-Limit Cutting and Silviculture in Northern Hardwoods............................. 16

Ralph D. Nyland

Overview of USDA Forest Service Research on Diameter-Limit Cutting 

in Northern Conifers................................................................................................ 24

Laura S. Kenefic, John C. Brissette, and Paul E. Sendak

Research on Diameter-Limit Cutting in Central Appalachian Forests........................ 32

Mary Ann Fajvan

Economics, Markets, and Diameter-Limit Cutting.................................................... 39

Kenny Fergusson

Genetic Effects of Diameter-Limit Cutting............................................................... 41

Gary Hawley, and Donald DeHayes, Paul Schaberg and John Brissettee

Ethics Considerations with Diameter Limit-Cutting................................................. 43

Victor L. Ford

Rehabilitating Cutover Stands: Some Ideas to Ponder ............................................... 47

Ralph D. Nyland


Facilitating a Dialogue About Diameter-Limit Cutting

Laura S. Kenefic1 and Ralph D. Nyland2

1

USDA Forest Service, Northeastern Research Station, Bradley, ME

2

Faculty of Forest and Natural Resources Management, 

SUNY College of Environmental Science and Forestry, Syracuse, NY

(1894) recounted the harvest of only the largest and best 

trees. In fact, diameter-limit cutting was recommended 

at the time as a means of preserving growing stock (Cary 

1907, Murphy 1917). With no markets for anything 

but high-value trees, large trees were selectively removed 

under the guise of selection silviculture. See Pinchot 

(1905) or Westveld (1949) for examples.

Some foresters raised concerns about diameter-limit 

cutting as early as the 1900s. Murphy (1917) reported 

that diameter-limit cutting was common in the spruce 

regions, but warned that failure to improve the smaller 

size classes or retain thrifty trees of large sizes would 

prevent sufficient yield to make cuts periodically. Later 

research led Blum and Filip (1963) and Roach (1974) 

to question the sustainability of structure and growth 

in diameter-limit cut stands. Seymour et al. (1986) 

expressed concern about “short-sighted, financially 

motivated cutting,” and encouraged wider application 

of silviculture. More recently, Kenefic et al. (2005) and 

Nyland (2005) concluded that repeated diameter-limit 

cutting reduced stand quality, value and long-term 

yields. Alternative silvicultural treatments were suggested 

(Kenefic and Nyland 2005).

Diameter-limit cutting is an integral part of our forest 

history in the Northeast, resulting in millions of acres of 

cutover lands. Many second-growth stands now contain 

poor quality stems, less valuable species, and variable 

stocking and crown cover as a result of past harvesting 

practices (Nyland 1992). At the dawn of the 21st century, 

Irland (1999) concluded that cutting in the Northeast 

generally was depleting stand quality and value far more 

than improving it.

Partial cuts focusing on extracting value continue to 

be widespread (Seymour 2005). Long-standing use 

of diameter-limit cutting has been little mitigated by 

findings from research about the benefits of silviculture. 

The short-term financial benefits of cutting only the 

Why a Conference About Diameterlimit Cutting?

Before embarking on an exploration of the specifics of 

diameter-limit cutting, we would be well served to ask 

ourselves, “Why is this topic important?” The answer 

to that question requires us to consider silviculture. 

Silviculture is “the art and science of controlling the 

establishment, growth, composition, health and quality 

of forests and woodlands to meet diverse needs and 

values on a sustainable basis” (Helms 1998). This 

definition highlights two critical features of silvicultural 

treatments: focus on residual stand condition and a longterm perspective.

Diameter-limit cutting means removing all merchantable 

trees larger than a specified diameter at breast height 

(Helms 1998). In practice, this usually involves the 

use of a fixed, or inflexible, diameter threshold, above 

which merchantable trees are harvested with retention 

of unmerchantable timber and without tending in the 

smaller size classes. Unlike silviculture, the focus of 

diameter-limit cutting is on what is removed, i.e. the 

largest and most valuable timber. A related practice 

is high grading, or removing the most commercially 

valuable trees from a stand. High grading is a more 

general term and encompasses diameter-limit cutting 

as commonly applied. Both practices are commodity 

driven: trees are selected for harvest based on an 

overriding interest in short-term revenue while bypassing 

the desirable features (focus on the residual and the longterm) of silviculture.

If the benefits of silviculture are acknowledged, why are 

commodity-driven harvests so common? An historical 

perspective provides some clues. Forestry, as a profession, 

became established in the Northeast in the late 1870s 

when the USDA Division of Forestry was formed, 

followed by state forestry commissions and forest 

societies in the 1880s and 1890s (Fernow 1913). Early 

reports of forestry practice, such as those by Austin Cary 
largest trees are compelling. This raises a number of 

questions: What historical factors shaped the widespread 

application of these cutting practices and discouraged 

silvicultural treatments? What are the long-term impacts 

of diameter-limit removals on the region’s forests? What 

are the economic and genetic implications? What are the 

ethical obligations of foresters considering diameter-limit 

cutting? And, perhaps most important, can we effectively 

rehabilitate the cutover forests of our region? 

The papers presented in this report reflect the content 

of a two-day conference for forestry practitioners, 

researchers, policy makers, and landowners at the 

University of Massachusetts on May 23-24, 2005. We 

hope that this presentation of the conference papers will 

help to sustain a dialogue about diameter-limit cutting 

in the Northeast and increase interest in opting for 

silviculture instead.

Literature Cited

Blum, B.M.; Filip, S.M. 1963. A demonstration of four 

intensities of management in northern hardwoods.

Res. Pap. 4. Upper Darby, PA: U.S. Department 

of Agriculture, Forest Service, Northeastern Forest 

Experiment Station. 16 p.

Cary, A. 1894. On the growth of spruce. In: Second 

annual report of the Forest Commissioner of the State 

of Maine. Augusta, ME: Burleigh & Flynt: 20-36.

Cary, A. 1907. Practical forestry on a spruce tract in 

Maine. Circ. 131. Washington, DC: U.S. Department 

of Agriculture, Forest Service. 15 p.

Fernow, B.E. 1913. A brief history of forestry in 

Europe, the United States and other countries.

3rd ed. Toronto, ON: Toronto University Press; 

Washington, DC: American Forestry Association. 

506 p.

Helms, J.A. 1998. The dictionary of forestry. Bethesda, 

MD: Society of American Foresters. 210 p.

Irland, L.C. 1999. The Northeast’s changing forest.

Petersham, MA: Harvard University Press. 401 p.

Kenefic, L.S.; Nyland, R.D. 2005. Diameter-limit 

cutting and silviculture in northeastern forests: 

a primer for landowners, practitioners, and 

policymakers. NA-TP-02-05. Newtown Square, 

PA: U.S. Department of Agriculture, Forest Service, 

Northeastern Area, State and Private Forestry. 18 p.

Kenefic, L.S.; Sendak, P.E.; Brissette, J.C. 2005. 

Comparison of fixed diameter-limit and selection 

cutting in northern conifers. Northern Journal of 

Applied Forestry. 22(2): 77-84.

Murphy, L.S. 1917. The red spruce: its growth and 

management. Bull. No. 544. Washington, DC: U.S. 

Department of Agriculture, Forest Service. 100 p.

Nyland, R.D. 2005. Diameter-limit cutting and 

silviculture: a comparison of long-term yields 

and values for uneven-aged sugar maple stands.

Northern Journal of Applied Forestry. 22: 111-116.

Nyland, R.D. 1992. Exploitation and greed in eastern 

hardwood forests. Journal of Forestry. 90(1): 33-37.

Pinchot, G. 1905. A primer of forestry. Part II – 

practical forestry. Washington, DC: U.S. Department 

of Agriculture, Bureau of Forestry. 88 p.

Roach, B.A. 1974. Selection cutting and group 

selection. AFRI Misc. Publ. No. 5. Syracuse, NY: 

SUNY College of Environmental Science and Forestry. 

9 p.

Seymour, R.S. 2005. Are we practicing forestry, or 

just harvesting timber? Reflections on balance in 

the forestry profession. Orono, ME: University of 

Maine. http://www.umaine.edu/fes/Seymour/seymour.

htm (accessed on November 15, 2005).

Seymour, R.S.; Hannah, P.R.; Grace, J.R.; Marquis, D.A. 

1986. Silviculture: the next thirty years, the past 

thirty years. Journal of Forestry. 84(7): 31-38.

Westveld, R.H. 1949. Applied silviculture in the 

United States. 2nd ed. New York: John Wiley & Sons. 

590 p.
Historical Perspective on Diameter-Limit Cutting 

in Northeastern Forests

Matthew J. Kelty and Anthony W. D’Amato

Department of Natural Resources Conservation, University of Massachusetts, Amherst

species are sometimes left standing. This kind of harvest 

is often called commercial clearcutting to distinguish 

it from the clearcutting regeneration method in which 

other site preparation or regeneration treatments would 

be incorporated.

This paper presents an overview of the methods of 

timber harvesting in the forests of the Northeastern 

United States from 1620 to 1950. The objective is 

to provide a historical context for current discussions 

about appropriate cutting methods for the region, 

particularly regarding the use of diameter-limit cutting. 

The paper focuses on the region encompassing the five 

New England states, plus New York, New Jersey, and 

Pennsylvania, but the general trends apply to surrounding 

areas as well. Figure 1 summarizes the types of harvesting 

generally used for the main species throughout this 

period. The range of harvests has been simplified to 

diameter-limit cutting for sawlogs vs. clearcutting in 

Figure 1. The diagram can give only a general outline of 

harvesting trends; details are provided in the text.

Agricultural and Early Industrial Eras 

(1620-1850)

Harvesting trees in the Northeast began as soon as 

settlements were established by English colonists in the 

1620s. Native American peoples living in the region 

had modified the forest landscape through burning and 

clearing for agriculture, but they lacked the technology 

for widespread harvesting of trees (Cronon 1983).

The earliest colonial timber harvests were to supply 

products for local use--for building houses and other 

structures and for fuelwood. However, the North 

American forests contained trees that were larger and 

far more abundant than in English forests, so an export 

market developed very quickly. Much has been written 

about the trade in large white pines (Pinus strobus) for 

masts for the British Navy, and this was certainly an 

important aspect of the early timber industry, but these 

were not the first timber products exported. The first 

Abstract

The use of diameter-limit cutting and high-grading is 

currently a concern for long-term sustainability of forests 

in the Northeastern United States and surrounding areas. 

This paper reviews historical information about the kinds 

of harvesting used in this region from 1620 to 1950, to 

provide a context for current discussions. Throughout 

this period, most timber harvests removed all trees that 

were in demand and that could be transported. Thus, 

nearly all harvests consisted of some type of diameterlimit cut, but the minimum diameter and the desired 

species varied so much that the harvests ranged from 

light partial cuts to nearly complete clearcuts. A period 

of widespread clearcutting from 1850 to 1920 to support 

the industrialization of the region created opposition 

to this practice, which resulted in attempts to shift 

most harvesting to some form of partial cutting. Thus, 

selection cutting (which often in practice was simply 

diameter-limit cutting or high-grading) became the 

method promoted by forest managers and silvicultural 

researchers for most forests in the early twentieth century. 

Introduction

Throughout much of history, societies have obtained 

most wood products by cutting trees from accessible 

forests without providing for sustainable production 

of new trees (Perlin 1991). This kind of exploitative 

harvesting nearly always consists of a diameter-limit cut 

in which trees larger than a given diameter (based on the 

products needed) are harvested (Helms 1998). If large 

beams, posts, and boards are required, the diameter limit 

is generally set at 10 to 16 inches, producing a harvest 

entirely of sawlog-size trees. The limit is not necessarily 

uniform, but can vary among species and stem forms. 

If only desirable species of good stem quality above the 

minimum diameter are cut, this kind of selective cutting 

is often referred to as high-grading. In other situations 

where fuelwood, pulpwood, or similar products are in 

demand, the minimum diameter is set very low. These 

may amount to a clearcut harvest, although undesirable 
ships carrying goods from the North American colonies 

to England included a load of white pine clapboards 

(Whitney 1994) and oak barrel staves (Hawes 1923). 

This was in 1622-23, before sawmills were in operation, 

so the products had been made with hand tools.

By the 1630s, the first sawmills had been established 

along the coast of Maine, and their numbers expanded 

quickly in the following decades until most coastal 

rivers had multiple mills (Hobbs 1906; Perlin 1991). 

The main species harvested and the principal products 

were as follows: white oak (Quercus alba) for barrel 

staves for transporting liquid contents (mainly wine), 

and for beams and boards for shipbuilding and house 

construction; red oak (Quercus rubra) for barrel staves for 

transporting solid or gel contents (sugar and molasses), 

and beams and boards for house construction; white pine 

and red spruce (Picea rubens) for shingles, clapboards, 

boards, and for ship masts and yardarms; and Atlantic 

white-cedar (Chamaecyparis thyoides) for shingles (Perlin 

1991; Gordon 1998; Irland 1999). The availability of 

large timbers in the American colonies for shipbuilding 

was so important that much shipbuilding shifted from 

England to New England (Perlin 1991; Gordon 1998). 

One interesting problem was that the stems of large white 

oak trees in New England were generally so straight that 

it was difficult to find the large stem-branch sections 

with curved grain to be used for the ships “knees” (Irland 

1999), but this was not a major impediment.

The selection of pines for ship masts had particularly 

exacting requirements, because a mast was ideally made 

Figure 1.—Time line summarizing the types of exploitative harvesting generally used for the main tree species in 

the Northeastern United States from 1620-1950. Harvesting types are simplified into “diameter limit,” which refers 

to cuts that removed only sawlog-size trees, and “clearcut,” which refers to cuts that removed nearly all trees.
from a single tree. Masts needed to be made from 

conifers, because they required strength, yet had to be 

light and flexible. The British Navy had made use of 

Scots pine (Pinus sylvestris) from Norway and other 

northern European countries, but the large trees in 

those forests had already been cut, so masts had to be 

fabricated from pieces of smaller Scots pine (Manning 

1979). The availability of single-tree masts from white 

pines in the North American colonies (some greater 

than 36 inches in diameter and 100 feet tall) was a great 

advantage over European sources. Mast logs had been 

shipped to England as early as the 1630s, but the trade 

began at a large scale in 1651. The famous Broad Arrow 

policy was put in place in a series of acts beginning in 

1691, and it continued in effect until the Revolution in 

1775. The Broad Arrow symbol was used by the British 

Navy to mark all of its property, and in this case, was 

used to designate all straight white pine trees 24 inches 

in diameter and larger (Manning 1979). Mast trees were 

the object of considerable controversy--the Navy’s mast 

agents had to compete with the colonial timber cutters 

who would ignore the laws, and turn mast trees into 

clapboards, shingles, and boards at their sawmills (Perlin 

1991).

The harvesting of mast trees was clearly a case of selective 

diameter-limit cutting (Whitney 1994). White pine 

occurred as a component in mixed stands containing 

hardwoods and hemlock (Tsuga canadensis). The mast 

harvesting focused on the emergent white pines that rose 

above the main overstory canopy. Initially, the harvesting 

of these selected pines was confined to the areas near the 

coast, but progressively moved up the coastal rivers.

Much more information exists about the kinds of 

products harvested in this era than about the original 

stand structure or the residual stand structure left 

following harvests. Although the special export products 

(barrel staves and ship masts) have received much 

attention, the wide range of wood products exported 

from Northeastern forests is revealed in accounts of 

two catastrophes: the destruction by fire of the cities of 

London, England in 1666 and Bridgeton, Barbados in 

1668 (Perlin 1991). In both cases, most of the supply of 

beams, boards, clapboards, and shingles to rebuild these 

cities was provided by the New England colonies. They 

had clearly become a major source of general oak and 

pine construction materials. These products would have 

nearly all been a result of selective diameter-limit cutting 

of trees of sawtimber size of the desired species.

However, not all harvesting was of that type. Fuelwood 

was needed in great quantities in towns and cities; 

stands in the surrounding areas were heavily cut for 

this purpose after large trees had been removed for 

other products. These stands regenerated by sprouting, 

especially if chestnut (Castanea dentata) was prevalent, 

and as they were harvested again, even-aged coppice 

stands developed. Overland transportation of wood was 

so expensive that the area for fuelwood production was 

limited to 5-20 mile radii around settlements (Whitney 

1994). Local stands were unable to supply the fuelwood 

needs of Boston and other cities within decades of 

settlement, and fuelwood was generally scarce in heavily 

populated areas of the east coast by 1800 (Whitney 

1994). Much fuelwood was transported by ship to these 

areas from remote forests.

The forest structure left by timber and fuelwood cutting 

would have varied geographically with accessibility 

and distance to towns. At the most distant points from 

population centers were forests that had been lightly 

high-graded for mast pines. In more accessible areas, a 

heavier diameter-limit cutting of oaks, pines, and other 

species would have occurred for boards, beams, shingles, 

and barrel staves. The areas closest to settlements 

consisted of agricultural land and woodlots that would 

have ranged from high-graded stands to nearly even-aged 

coppice stands. These zones progressively spread outward 

over time, as population and agricultural areas expanded; 

however, remote areas of the Northeast still had much of 

their virgin timber intact in 1850, 200 years after initial 

European settlement, largely because of the difficulties of 

overland transportation.

Silvicultural Ideas, Practices, and 

Policies

Few laws or regulations controlled timber harvesting 

in this era, except for those that specified ownership of 

land or trees. The Broad Arrow policies were designed 
to reserve mast trees for the Navy, not to plan for 

sustained production of those kinds of trees. There were 

some laws that protected smaller trees from cutting, to 

provide growing stock for future harvests; one example 

is an order for the town of Woburn, Massachusetts in 

1640 that protected oaks less than 8 inches in diameter 

from cutting, thus mandating diameter-limit cutting to 

maintain trees for the future (Hawes 1923). However, 

there is little evidence that such laws were widespread. 

The main practice in use in settled areas at this time was 

a rough kind of coppice harvest with a rotation of about 

25 years (Whitney 1994).

Era of Clearcutting for Wood-Based 

Industries (1850-1910)

The Industrial Revolution during the mid-nineteenth 

century broadened the kinds of wood being used 

from the forests in the Northeast and increased the 

volumes needed to sustain the growing industries, 

cities, and populations within the region. In particular, 

the development of industries such as pulp and paper, 

industrial charcoal, and boxboards, which utilized large 

volumes of lower quality wood, shifted the focus of 

timber harvesting activities in much of the Northeast 

from the selective cutting of large, high quality trees to 

heavy cuttings in which nearly every tree was considered 

merchantable.

The timing of the increase in industrial uses of wood 

varied across the region. It began earliest near the 

population centers along the Atlantic coast and the major 

rivers, where there had already been more than one wave 

of diameter-limit cutting, as well as coppice cutting for 

fuelwood in some cases. The shift in cutting practices 

from diameter-limit cutting of sawlogs to clearcutting 

occurred much later in the northern and western portions 

of the Northeast. Much of this area, including the 

Adirondacks, northern Maine, and central and western 

Pennsylvania had been largely inaccessible prior to the 

1850s (Whitney 1994). With the advent of the railroad 

in the 1830s (Muir 2000), the logging industry was 

able to expand into these remote areas, resulting in a 

new wave of diameter-limit cutting for sawlogs, but this 

shifted to clearcutting quickly. The process of this shift is 

described separately for the four main forest types, which 

were controlled by different markets.

Oak-Pine Forest Type

Extensive agricultural abandonment in the 1850s resulted 

in the development of large expanses of white pine 

forests on former agricultural fields, mainly in southern 

New England (Foster and O’Keefe 2000). In areas that 

had remained forested during agricultural expansion, 

repeated diameter-limit harvesting for sawlogs and 

extensive cutting for fuelwood created stands containing 

predominantly coppice hardwoods or low value 

hemlocks. While the amount of forested area greatly 

expanded in the region during this time period, the size 

and quality of the trees were much lower than what had 

supplied earlier forest industries.

An industry formed around these second-growth stands, 

which ranged from 50 to 100% white pine, and were 

even-aged, but of poor quality (Westveld 1935; Gould 

1960). The trees had many large branches, and were 

deformed by the white pine weevil (Pissodes strobi), but 

they were still perfectly acceptable for boxboards—the 

short boards used for many types of shipping containers 

(crates and boxes). These were generally harvested 

with nearly complete clearcuts that left only advance 

regeneration hardwoods. This industry grew to its largest 

extent from 1890 to 1920.

Cordwood of various hardwood species was the only 

source of home heating until coal and coal stoves 

became readily available in the early 1800s. Coal stoves 

became numerous enough to have a substantial effect 

on fuelwood demand in cities by 1830, and there was a 

steady shift from wood to coal as a percent of the energy 

source used in the region (Whitney 1994). However, 

even as this shift occurred, the increased heating demand 

for all energy sources from the growing population meant 

that wood use for domestic heating reached a peak in 

1870. Despite this peak in the late 1800s, there was still 

significant cordwood cut for use in rural areas as late as 

the 1920s.

Industrial charcoal added to the demand for fuelwood 

to be used for iron, brass, lime, and brick production. 

Although it was not nearly as important as domestic 

heating in total use of cordwood supplies, it had 

significant effects on regions where these industries were 

located, including southern New England, northern New 
Jersey, and western Pennsylvania. Iron furnaces had very 

large fuelsheds, and often these operations continued 

widespread clearcutting until the wood supply was 

exhausted, leaving large areas of young sprout hardwood 

regeneration.

Hardwood railroad ties also gained importance at this 

time. Each mile of new railroad and trolley track needed 

more than 2500 ties, mostly made of oak (Gordon 

1998). These could be obtained from small trees as part 

of heavy fuelwood cutting.

Hemlock Forest Types

Hemlock was a component species of many forest types 

throughout the Northeast, and was the most abundant 

species in many cases. It was less desirable than pine or 

spruce as a timber species, but the larger hemlocks were 

sometimes cut with the other conifers in diameter-limit 

harvests. A major shift in the demand for hemlock came 

when it was discovered that its bark was an excellent 

source of tannins for treating leather. The earliest 

tanneries in the United States were small operations in 

southern New England that had only local importance 

(Bürgi et al. 2000). They initially used oak bark as the 

source of tannins, following the European methods that 

relied on oak and spruce. However, hemlock became the 

main source in the Northeast by 1800 (Millen 1995). 

Large tannery operations were established in the Catskills 

in the 1820s because of the predominance of hemlock in 

the area. Hemlocks were felled and the bark was peeled 

and hauled on sleds to tannery sites, with the hemlock 

logs generally left in the woods. By 1850, the hemlock 

supply was declining in the region, with much of the 

land having been clearcut. The industry moved to the 

Adirondacks, Maine, and Pennsylvania where hemlock 

was still abundant. A major center for tanneries was in 

north-central Pennsylvania (Irland 1999). Logging in 

that region had begun in 1850 to selectively remove 

the large pines. As the pine was depleted, hemlock was 

cut for lumber production; then the harvesting for 

tanneries began, with both bark and logs being used. 

Large water-powered tanneries were established in the 

1870s, and surrounding stands were cut so clean that 

settlers easily converted many of the post-harvest areas to 

farms. These were not restricted to areas with good river 

transportation; tanneries were also distributed along the 

railroads of the area. Tanbark was shipped out by rail to 

operations in other regions, as well as for use by local 

tanneries. The operations in this region declined as the 

hemlock supply was exhausted, and the leather finishing 

process changed to the use of chrome salts instead of 

tannins in the 1890s.

Spruce-Fir Forest Type

The history of diameter-limit harvesting of red spruce in 

northern New England and the Adirondacks was quite 

different from that of other species. In contrast to the 

moderately tolerant white pine and oak, which typically 

failed to regenerate high quality stems after diameterlimit harvesting, the shade tolerance and abundant 

advance regeneration characterizing red spruce allowed it 

to survive and develop in height following these harvests 

(Westveld 1939). Early diameter-limit harvesting of red 

spruce focused primarily on procuring sawlogs to fuel 

the thriving lumber industry throughout the Northeast 

(Whitney 1994; Welsh 1995; Gove 2003). While much 

of this industry had been built on white pine lumber, red 

spruce was quickly recognized as a valuable substitute for 

this much-depleted resource (Whitney 1994). Red spruce 

quickly replaced white pine as the major species being 

cut for lumber in the Adirondacks and Maine by 1850-

90 (Cary 1896; Welsh 1995). Early sawlog harvests of 

red spruce focused solely on larger diameter trees above 

12-16 inches (Linn 1918; Churchill 1929; Dana 1930; 

Seymour 1992; Welsh 1995). These large-diameter trees 

quickly became rare, but improving markets for spruce 

lumber (Gove 2003) resulted in repeated cutting of these 

stands to successively lower diameter limits (Seymour 

1992). By the 1890s all trees above a stump diameter 

of 8-10 inches were being harvested (Churchill 1929; 

Seymour 1992; Welsh 1995).

A technological development then changed the demand 

and harvest methods for red spruce. The northern 

hardwood-red spruce type extends south into the 

Berkshire Plateau region of western Massachusetts. 

This overlap between the heavily industrialized part 

of southern New England and a supply of spruce led 

to the early use of wood for paper production. The 

first wood-based pulp mill in the United States was 

established in a converted textile mill in the town of Lee, 
MA in 1867 (Gordon 1998). The harvesting method 

consisted of removal of all red spruce and balsam fir 

(Abies balsamea). The number of pulp mills in this area 

expanded so rapidly that the spruce and fir supply was 

exhausted by 1890 and the mills began to close. The 

paper industry shifted east to mills in the city of Holyoke 

on the Connecticut River, and the pulpwood harvest 

moved to Vermont and New Hampshire, with the spruce 

and fir pulpwood being driven on the River to the mills 

(Whitney 1994; Muir 2000).

This increased emphasis on harvesting pulpwood resulted 

in continued lowering of the diameter-limit to levels 

as low as 5 inches in places such as the Adirondacks 

(Churchill 1929; Juvenal 1906 cited in Welsh 1995). 

In addition to these lower diameter limits, balsam fir, 

a species primarily ignored in earlier spruce harvests, 

was also cut for pulpwood (Oosting and Reed 1944). 

As the demand for pulp increased and new, previously 

inaccessible areas of forest were opened to logging via 

railroad expansion, harvesting practices changed to 

extensive clear-cutting for pulpwood throughout the 

region (Westveld 1928; Dana 1930; Oosting and Reed 

1944; White and Cogbill 1992; Welsh 1995).

Northern Hardwood Forest Type

Diameter-limit cutting was less widespread in the 

northern hardwood forests of northern New England 

and the Adirondacks during the industrial era. Logging 

during this period was generally restricted to the most 

accessible hardwood stands because hardwood logs do 

not float; this changed with the advent of widespread 

railroad systems (Linn 1918; Dana 1930; Blum and 

Filip 1963). Harvesting within these stands was very 

selective and typically only removed the larger, wellformed hardwoods for use in furniture making and other 

construction purposes (McQuilkin 1957; Gilbert and 

Jensen 1958; Blum and Filip 1963). In addition to these 

diameter-limit harvests, accessible northern hardwood 

stands were also clearcut during this period for fuelwood, 

as well as to supply the charcoal and chemical distillation 

industries (Gilbert and Jensen 1958).

In areas of the Northeast where these northern hardwood 

stands contained a red spruce component, such as New 

Hampshire and Vermont, diameter-limit harvesting of 

red spruce was a widespread practice (Linn 1918; Dana 

1930). Initial harvests in these stands during the late 

nineteenth century focused solely on selectively removing 

red spruce, with a minimum diameter limit of 12-14 

inches (Linn 1918; Bormann et al. 1970; White and 

Cogbill 1992). However, in most cases these harvests 

served to increase the proportion of hardwood species in 

the stand at the expense of spruce (Linn 1918; McCarthy 

1919). The use of logging railroads in these regions 

(Oosting and Reed 1944; White and Cogbill 1992) and 

the introduction of new markets for hardwood species 

and smaller diameter red spruce resulted in clearcutting 

of these stands in subsequent harvests. As a result, 

clearcutting was practiced extensively in these mixed 

species forest types (as in the spruce-fir type) at the turn 

of the nineteenth century and beginning of twentieth 

century (Oosting and Reed 1944; Bormann et al. 1970; 

White and Cogbill 1992; Schwarz et al. 2001).

Silvicultural Ideas, Practices, and 

Policies

The hardwood charcoal production for the iron industry 

in Pennsylvania and the white pine boxboard industry in 

southern New England led to some of the first attempts 

at industrial forest management in the United States 

to use managed coppice and shelterwood methods. 

However, the greatest response to the heavy industrial 

clearcutting was a call to reserve valuable trees on the sites 

rather than to simply cut all commercial stems. This was 

focused on red spruce, likely because of the speed with 

which this species was harvested.

Slash fires, extensive damage to residual trees, and the 

failure of red spruce to successfully regenerate following 

clearcutting resulted in several early calls of concern 

regarding clearcutting in the spruce-fir region at the 

turn of the nineteenth century (Cary 1894; Pinchot 

1898; Ayres 1903; Merrill 1959). Early foresters such as 

Gifford Pinchot and Austin Cary advocated harvesting 

systems that cut red spruce only above a set diameter 

limit between 10-14 inches due to the previous success of 

diameter-limit cutting in regenerating red spruce (Cary 

1894; Pinchot 1898). Large-scale clearcutting in the 

spruce-fir forests of Vermont led the governor to include 

in his address to the state in 1894 a recommendation for 

the implementation of a 10-inch diameter limit in spruce 
forests (Merrill 1959). Similarly, the New Hampshire 

legislature discussed proposals during the 1890s for laws 

restricting harvesting spruce below a given diameter 

limit (Ayres 1903). Thus, a major initial impetus for 

forest conservation in the 1890s was the shift from 

partial cutting of spruce stands to clearcutting, with 

the proposed solution being to reinstate diameter-limit 

cutting as the preferred harvest method.

Era of Early Silviculture and Forest 

Conservation (1910-1950)

Oak-Pine Forest Type

In the early twentieth century, most of the market 

demand that had led to clearcutting in the oak-pine 

type began to disappear. Domestic fuelwood, industrial 

charcoal, tanbark, and chemical wood were all being 

replaced by coal, oil, and petroleum-based chemicals. The 

pine boxboard market continued through the 1950s and 

beyond, but at a much reduced scale due to the effects of 

the 1938 hurricane and the development of cardboard 

packaging. Much of the landscape was covered with 

young even-aged stands, having few trees of merchantable 

size for sawlogs.

In contrast, the value of high-grade hardwoods and pine 

was increasing at that time for furniture, flooring, and 

finish material (Gordon 1998). A substantial demand 

also continued for lower grade hardwood for railroad 

and trolley ties. These market conditions would be 

expected to lead to cutting methods that either favored 

the production of larger timber through thinning, 

or focused on cutting only sawlog trees. However, 

clearcutting continued to be common. This was in part 

simply because it was a “deeply ingrained practice” in the 

region (Cline 1944). Also, most milling was done with 

portable sawmills, and once set up, the crews insisted 

on cutting every merchantable tree in the area (Hawes 

1929). Forested land had such low value in southern New 

England, that timber sales sometimes included the land 

itself, and the sawmill crews generally clearcut the tract. 

If only the timber was included in a sale, it was generally 

specified that the cutting rights were for trees greater 

than a specified diameter, thus requiring a diameter-limit 

cut; these practices continued through the 1950s (D.M. 

Smith, personal communication, 2005).

However, there were economic arguments being 

developed in this period that called into question the 

financial benefits of clearcutting. The general rule at 

the time was to cut every tree that met the minimum 

merchantable criteria for the available market. Time 

and motion studies and sawmill yield analyses led to the 

conclusion that “often there is no profit, but instead a 

loss, in cutting small trees even though of size to give 

merchantable products” (Hawley 1938). Hawley noted 

that this was not news to professional foresters, but it had 

not been communicated widely. An example of research 

on this topic was that of Cunningham and Ferguson 

(1946) on harvesting hardwoods for railroad ties in 

Connecticut; the conclusion was that ties should be made 

from trees 18 inches and larger, rather than using trees as 

small as 10 inches, as was commonly done.

In addition, foresters and legislators were advocating 

selection cutting at that time (see further discussion 

below), even though much of the cutting that was 

described as selection was diameter-limit or high-grading. 

Thus, a combination of clearcutting, diameter-limit 

cutting, and high-grading continued in the pine-oak 

region throughout the period.

Spruce-Fir Forest Type

Despite early concern regarding the sustainability of 

clearcutting practices within the spruce-fir region at the 

turn of the nineteenth century, this continued to be the 

predominant mode of harvesting during the early and 

mid 1900s (Westveld 1928, 1939; Oosting and Reed 

1944; White and Cogbill 1992; Welsh 1995). This was 

motivated primarily by the needs of a thriving pulp and 

paper industry in the Adirondacks and northern New 

England (Harper 1947; Oosting and Reed 1944; Welsh 

1995). The development of harvesting technology such 

as logging trucks and tractors in the 1920s (Oosting and 

Reed 1944; Welsh 1995) and chainsaws and rubber-tired 

skidders in the 1940s and 1950s (Cogbill and White 

1992; Welsh 1995) increased the efficiency with which 

remote areas within this region could be harvested to 

supply the large demand for pulpwood.

Within the spruce-fir forests of Maine, much of the red 

spruce diameter-limit harvests in the late 1800s had 
10

resulted in an increase in balsam fir in residual stands by 

the early 1900s (Zon 1914; Seymour 1992). As a result 

of the artificially high abundance of fir on the landscape, 

an extensive spruce budworm (Choristoneura fumiferana) 

outbreak occurred from 1913-1919, causing widespread 

mortality of merchantable spruce and fir throughout the 

region (Seymour 1992). To forestall pulpwood shortages, 

harvesting operations following these outbreaks in the 

1920s covered extensive areas, salvaging damaged stands 

and clearcutting stands that had survived the outbreak 

(Seymour 1992).

The devastating impacts of the budworm on the longterm pulpwood supplies combined with continued 

criticisms of clearcutting resulted in a reevaluation of 

the silvicultural systems most appropriate for sprucefir stands (Murphy 1917; Dana 1930; Westveld 1939; 

Harper 1947; Westveld 1953). In many cases, suggestions 

included the use of true selection systems to promote 

spruce and fir reproduction and maintain a greater 

amount of merchantable growing stock (Zon 1914; 

Murphy 1917; Harper 1947; Westveld 1953). However, 

these suggestions were often misapplied in the form of 

diameter-limit harvests (Murphy 1917) or criticized 

due to the propensity of residual stands to windthrow 

damage (McCarthy 1919; Dana 1930; Fletcher 1944). 

To avoid these losses to windthrow, diameter-limit 

cutting to a very small diameter was suggested as an 

alternative to selection systems, particularly in situations 

such as spruce flats where spruce and fir advance 

regeneration were abundant and risk of windthrow was 

high (Linn 1918; Westveld 1928; Dana 1930); this 

kind of cut would now be called an overstory removal 

(i.e., a clearcut that reserves advance regeneration). As a 

result of these suggestions, both overstory removal and 

diameter-limit harvests of sawtimber red spruce became 

the predominant modes of harvesting from the 1940s 

through the 1960s (Oosting and Reed 1944; Harper 

1947; Hart 1963).

Northern Hardwood Forest Type

Improvements in logging technology and the 

development of new markets for hardwood veneer 

and pulp resulted in increased utilization of northern 

hardwood forests from the 1910s through the 1950s 

(Dana 1930; McQuilkin 1957; Blum and Filip 1963). 

Harvesting practices in these forest types over this period 

ranged from large-scale clearcutting for pulpwood and 

chemical wood to diameter-limit harvests of high quality 

veneer logs from previously inaccessible old-growth 

stands (Dana 1930; Gilbert and Jensen 1958; Blum and 

Filip 1963). In many cases, large diameter hardwoods 

were selectively removed from stands that had previously 

been harvested for red spruce during the late 1800s and 

early 1900s (Blum and Filip 1963; Bormann et al. 1970). 

By the 1950s, these harvesting practices had resulted 

in much of the hardwood forests in the region existing 

in a fairly degraded state. Despite earlier management 

guidelines advising the removal of cull or ‘wolf’ trees 

during diameter-limit harvests (Dana 1930), most 

stands subject to repeated diameter-limit harvests were 

now predominantly composed of large, poor quality 

stems interspersed with smaller, non-merchantable trees 

(Westveld 1956; Gilbert and Jensen 1958; Blum and 

Filip 1963).

Despite the degraded state of many northern hardwood 

stands, the strong markets for large veneer-quality 

hardwood logs necessitated the development of 

silvicultural guidelines for sustainably managing these 

stands (e.g., Gilbert and Jensen 1958; Blum and Filip 

1963). In general, selection systems became the preferred 

approach for northern hardwood stands (Blum and 

Filip 1963). While these management recommendations 

included the removal of cull hardwoods, the 

misapplication of these selection systems resulted in the 

continued degradation of many old-growth stands in the 

region (MacAdam 1950).

Silvicultural Ideas, Practices, and 

Policies

The early calls for using diameter-limit cutting for red 

spruce in the 1890s (as an alternative to clearcutting) 

were continued in the early twentieth century, and 

expanded to other forest types. Gifford Pinchot 

advocated selection harvesting, which was acceptable to 

the logging industry because it was economically feasible 

(Boyce and Oliver 1999). The harvesting was often 

actually diameter-limit cutting or high-grading, but it 

was a clear improvement over widespread clearcutting. 

Forestry journals and textbooks (e.g., Hawley 1946; 

Meyer 1952) began to add the ideas and experience 
11

from Swiss and German selection forestry to the simple 

approach of partial cutting. A good deal of U.S. Forest 

Service research was focused on growth-and-yield and 

regeneration in partially cut stands, and selection cutting 

was promoted in advice given to private landowners (e.g., 

Hawley and Goodspeed 1932). Foresters devised many 

variants of the method; the terms “economic selection”, 

“improvement selection”, “maturity selection”, “wartimber selection”, and “businessman’s selection” (as well 

as “single-tree” and “group” selection) were all discussed 

in the Journal of Forestry in the 1930s-50s. Some of 

these were creative applications of selection principles to 

specific forest types to promote regeneration and longterm economic goals; others were devised to meet shortterm financial goals. 

In the Northeast, any kind of partial cutting was seen 

as an improvement over the clearcutting that had been 

prevalent. For example, Cline (1944) noted that: “This 

very practice of clearcutting has been the largest single 

factor contributing to the decline of Massachusetts 

forests during the past 50 years.” Some of the opposition 

to clearcutting resulted from associating the drastic 

overcutting that was occurring at a landscape scale with 

the clearcut harvest method being used. The possibility 

of federal regulation of cutting on private lands was being 

considered, and New England states were debating and 

in some cases passing state regulations as an alternative 

(Lambert 1944; Merrill 1959). Some of these sought to 

reduce clearcutting, but with minor requirements such as 

retaining seed trees.

An example of the lack of discrimination concerning 

the kind of partial cutting to be promoted is found 

in a brochure of The New Hampshire Forestry and 

Recreation Commission (1947) that dealt with forestry 

problems in the state. Two photographs (Fig. 2) show 

the harvesting method to be avoided (a clearcut lot) in 

contrast to the appropriate method (a selectively cut 

lot). Close inspection of the photographs shows that the 

residual stand left after selective cutting is made up of 

tall, thin trees with small crowns, recently of suppressed 

or intermediate crown classes, scattered among large 

stumps. This appears to be a ill-conceived diameter-limit 

cut of an even-aged stand, yet is presented as a harvesting 

method to be emulated.

Hawley (1938) considered partial cutting as an easy way 

to introduce private landowners to forest management, 

similar to Pinchot’s use for initially engaging forest 

industry in improving their practices. However, Hawley 

did not consider it the best alternative for all stands. 

He wrote: “...in the effort to take advantage of partial 

cutting and selective logging as a bait for leading private 

owners into the practice of forestry, professional foresters 

have in some instances attempted to extend this style of 

cutting to situations outside its legitimate range. It has in 

some cases amounted almost to a deification of partial as 

contrasted to complete cutting of the stand.”

The period of 1920-50 had clearly become a time 

when selection harvesting had gained the support of 

most of the forestry profession, but in many ways the 

choices of harvest method (as actually practiced) had 

not advanced very far beyond clearcutting vs. diameterlimit cutting for sawlogs. The landscape-level problems 

with clearcutting were clear, and there was interest in 

re-vegetating watersheds, restoring and maintaining 

landscape aesthetics, and producing large high quality 

timber. But Hawley gave one of the strongest warnings 

about shifting without question to the other alternative, 

when he wrote: “Let us ... envision the future results 

of any partial cutting ... not only on the basis of the 

immediate financial profit of the operation, but also 

upon its ultimate consequences. Use the propaganda 

value of selective logging for all it is worth, but be honest 

with yourself and do not be led into thinking that partial 

cutting or selective logging is a panacea which will solve 

all the problems of silviculture.”

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Blum, B.M.; Filip, S.M. 1963. A demonstration of four 

intensities of management in northern hardwoods.

Res. Pap. NE-4. Upper Darby, PA: U.S. Department 

of Agriculture, Forest Service, Northeastern Forest 

Experiment Station.

Bormann, F.H.; Siccama, T.G.; Likens, G.E.; Whittaker, 

R.H. 1970. The Hubbard Brook ecosystems study: 
12

Figure 2.—Photographs originally presented by the New Hampshire Forestry and 

Recreation Commission (1947) indicating the ideas about preferred harvesting methods 

that were generally held in the first half of the 20th century. According to these ideas, 

clearcutting (A) was to be avoided in favor of selective cutting (B). However, many of the 

very heavy cuts tended to produce the best regeneration, whereas many selectively cut 

stands were left with poor-quality residual trees.

(a)

(b)
13

composition and dynamics of the tree stratum.

Ecological Monographs. 40: 373-388.

Brown, W.R. 1958. Our forest heritage: a history 

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Fletcher, E.D.; Hawes, A.F. 1928. The use of lumber 

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917-922.

Hawley, R.C. 1938. Professional honesty as regards to 

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Hawley, R.C.; Hawes, A.F. 1912. Forestry in 

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Petersham, MA: Harvard University Press. 401 p.

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Linn, E.R. 1918. Silvical systems in spruce in northern 

New Hampshire. Journal of Forestry. 16: 897-908.

MacAdam, W.C. 1950. Hardwood utilization in 

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343-345.

Manning, S.F. 1979. New England masts and the king’s 

broad arrow. Kennebunk, ME: Thomas Murphy. 52 p.

McCarthy, E.F. 1919. Observations on unburned cutover lands in the Adirondacks. Journal of Forestry. 

17: 386-397.

McQuilkin, W.E. 1957. Look to the hardwoods. Res. 

Pap. NE-91. Upper Darby, PA; U.S. Department 

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Merrill, P.H. 1959. A history of forestry in Vermont.

Montpelier, VT: Vermont State Board of Forests and 

Parks. 66 p.

Meyer, H.A. 1952. Structure, growth, and drain in 

balanced uneven-aged forests. Journal of Forestry. 

50: 85-92.

Millen, P.E. 1995. Bare trees: Zadock Pratt, master 

tanner and the story of what happened to the 

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Backdome Press. 100 p.

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Hanover, NH: University Press of New England. 312 

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management. Bull. No. 544. Wasthington, DC: U.S. 

Department of Agriculture. 100 p.

New Hampshire Forestry and Recreation Commission. 

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efforts at solution undertaken or in prospect.

Inf. Leaf. 4. Concord, NH: New Hampshire State 

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15

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the Adirondacks 1850-1950. Utica, NY: North 

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spruce-fir forests of eastern North America. Journal 

of Forestry. 51: 422-430.

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New England. Journal of Forestry. 54: 332-338.

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16

Diameter-Limit Cutting and Silviculture in Northern Hardwoods

Ralph D. Nyland

Faculty of Forest and Natural Resources Management, State University of New York 

College of Environmental Science and Forestry, Syracuse

Key Considerations for Even-aged 

Stands

Even-aged northern hardwood stands have a major 

component of shade-tolerant species and may include 

pure stands of sugar or red maple. Yet many also have 

trees of lower shade tolerance as well. As both kinds of 

stands develop, differentiation occurs in heights and 

diameters, within and between species. This commonly 

results in a wide spread of tree sizes, giving the diameter 

distribution a reverse-J shape. Such stands usually have a 

single canopy layer, with trees of both species groups in 

dominant and codominant positions. This differentiation 

in size among trees reflects unequal rates of development 

that has implications for management.

In cases with more than about one-third of the basal 

area in shade-intolerant species, stands commonly 

develop a two-layered structure. These highly stratified 

mixed-species stands often have a bi-modal diameter 

distribution, with separate segments for the dominant 

shade-intolerant species and another for the slowergrowing shade-tolerant understory. Diameter growth will 

vary among trees within each species group, except that 

overtopped trees of the shade-intolerant species usually 

die early during stand development, leaving others mostly 

of upper-canopy positions and larger diameters.

Highly stratified stands require special consideration 

in their management. These might include appropriate 

removal of some species, and cutting of trees from only 

designated size classes. For example, if a stratified mixedspecies stand had short-lived shade-intolerant species 

in the overstory (e.g., paper birch and aspen), cutting 

might appropriately remove those large trees before ones 

of the understory (e.g., sugar maple) reach operable 

sizes (see Leak 1999). When more long-lived species of 

low shade tolerance dominate the overstory (e.g., black 

cherry and white ash), but have begun to decline in vigor 

due to aging, cutting might appropriately reduce their 

numbers. Yet to insure adequate representation of these 

The Situation

North American forestry has a long history of diameterlimit removals and other forms of selective cutting 

in uneven-aged stands (Kelty and D’Amato this 

proceedings). Its use increased among even-aged forests 

beginning in the 1980s as trees in naturally reforested 

stands on former agricultural sites and other kinds of 

second-growth stands reached sawtimber sizes (Nyland 

1992). Other assessments of timber harvesting have more 

recently identified diameter-limit cutting as a widespread 

practice in many regions of northeastern North 

America (Fajvan et al. 1998; Pell 1998; Nyland 2000). 

Practitioners cite the ease of application (no marking or 

other close control over cutting), high first-entry yields 

and associated revenues (usually all the merchantable 

trees taken), and the higher rate of interest expected from 

removing all or most of the value from a stand. They 

usually do not cite any ecologic effects, changes in visual 

qualities as a consequence of the cutting, and effects on 

other non-market values. Further, arguments usually 

do not consider the long-term implications if used over 

multiple entries to a stand, but focus on a single cutting 

and what it initially brings to a landowner.

The traditional emphasis on financial aspects of diameterlimit cutting, compared to the silvicultural alternatives, 

begs answers to two key questions:

1. Does diameter-limit cutting result in greater 

long-term yields when used over multiple cutting 

cycles?

2. Will long-term revenues from stands operated 

by diameter-limit cutting exceed that from 

conventional silvicultural practices?

To address these matters I used simulation methods to 

compare diameter-limit cutting with crown thinning in 

even-aged stands, and with selection system silviculture 

for uneven-aged ones. The simulations included multiple 

consecutive entries to each test stand, and compared 

three examples for each stand condition.
17

species in the next rotation, some minimum stocking 

of well-dispersed individuals of good vigor must remain 

as a future seed source (e.g., Marquis 1994). In cases 

where the understory species has little commercial value 

(e.g., hophornbeam) or might eventually interfere with 

regeneration of more desirable trees (e.g., beech and 

striped maple), a type of reverse diameter-limit cutting 

(e.g., A or B grade thinning from below) might prove 

important as a site preparation measure prior to the end 

of a rotation. So due to these and other complexities of 

species composition, and their implications for longterm management, my assessment did not consider 

stratified mixed-species stands.

Table 1 shows the post-thinning diameter growth 

for sugar maple trees in a 70- to 75-yr old northern 

hardwood stands where shade-intolerant species 

comprise only about 15-20% of the basal area (after 

Nyland et al. 1993). Over the 15-yr observation 

period, codominant sugar maple trees grew at about 

66% the rate of dominants, intermediates at 46%, and 

overtopped trees at 23%. Earlier, Marquis (1991) had 

shown a similar disparity among crown classes in mixedspecies Allegheny hardwood stands. Further, differences 

between them increased as stands aged, particularly for 

the intermediate and overtopped trees. Such findings 

illuminate a major effect of diameter-limit cutting in 

even-aged stands, compared to crown thinning. The 

latter favors trees of upper-canopy positions, removing 

adjacent ones of lower vigor and poorer quality. It 

controls spacing between the residuals, and concentrates 

the growth potential of a site onto trees of the best grade 

and quality. Diameter-limit cutting just removes the bestgrowing trees (as indicated in Table 1).

Thinning also regulates the residual density to insure 

full site utilization and full net volume production until 

the next entry. Diameter-limit cutting simply removes 

the largest and most vigorous trees from even-aged 

stands without controlling the level of residual stocking 

or regulating the spacing between the trees left behind. 

Further, it makes no attempt to improve stand quality 

by removing trees of poor quality and grade from the 

residual size classes.

Effect of Diameter-Limit Cutting on 

Long-term Production from Even-aged 

Stands

To explore similarities and differences between crown 

thinning and diameter-limit cutting, I simulated the 

development of three real even-aged stands for three 

successive entries through time. The simulations started 

with the pre-cutting diameter distribution (1-in. 

classes) for each stand. For the diameter-limit cuttings 

I removed all trees ≥12 in. dbh, and simulated stand 

growth for an appropriate time until it would support 

another diameter-limit removal (15 yrs in most cases). 

The crown thinnings reduced stocking to 60% relative 

density, taking 2/3 of the cut among trees smaller than 

the median stand diameter (DM1), and 1/3 in trees 

above DM. The simulations projected development after 

each cutting by stand table projection, using movement 

percents for an appropriate cutting cycle based on 

remeasurement of trees in a thinned stand of similar 

species composition and degree of development. For 

neither type of cutting did the simulations add ingrowth 

of new trees to the stands, but in all cases I assumed that 

the cuttings controlled mortality. I simulated three entries 

for each pair of treatments, with the last one serving as a 

reproduction method to end the rotation.

1

DM reflects the diameter at the midpoint of the distribution 

of basal area among trees ≥6 inches dbh, using basal area per 

diameter class as a weighting factor in calculating the average 

diameter (see Marquis et al. 1992).

Table 1.—Fifteen-year post-thinning 

diameter growth of sugar maple trees 

having different initial crown positions, 

Adirondack northern hardwoods (after 

Nyland et al. 1993).

Crown position 15-yr diameter 

growth

Inches

Dominant 2.98

Codominant 1.95

Intermediate 1.36

Overtopped 0.69
18

Table 2 shows initial conditions in the three test stands, 

and Table 3 the comparative levels of simulated sawtimber 

volume production from the different treatments in each 

one. It also shows that the diameter-limit cuts took no 

pulpwood at any entry. By contrast, thinning removed 

10 to 11 cds/ac for the first entry to these stands, and 

additional pulpwood with each subsequent cut. Further, 

the thinning regimes provided 1.2 to 1.3 times more 

cumulative board-foot volume for the entire rotation. 

Quite important, they yielded 71%, 73%, and 74%, 

respectively, of the total sawtimber volume from trees at 

least 16 in. dbh (potentially Grade 1

trees). For diameter-limit cutting these 

proportions were 8%, 11%, and 13%.

Effect of Diameter-Limit 

Cutting on Long-term 

Revenues from Even-aged 

Stands

Table 4 shows the value of simulated 

sawtimber yields, with stumpage price 

applied by tree diameter and grade, 

based upon the price of sugar maple 

lumber in 2003. The simulations 

assumed that each tree would have the 

highest grade possible for its diameter 

(Grade 3 for 12-in. trees, Grade 2 

for those 13 through 15 in. dbh, and 

Grade 1 for trees ≥16 in.). Revenues 

from the thinning regimes exceeded 

those for diameter-limit cutting by 

200%, 179%, and 176%, respectively, 

for the three stands. This reflects the 

greater proportion of cumulative 

volume from trees ≥16 in. dbh, and 

the higher stumpage value of those 

trees. Harvest revenues discounted to 

the time of the first entry (at 4%, 6%, 

and 8% rates of interest) had positive 

present net worth (PNW) values from 

both strategies. Generally, they were 

higher for diameter-limit cutting with 

discount rates in excess of 4%. This 

contrasts with the appreciably higher 

rotation-long sales revenues from the 

stands treated by crown thinning, 

Table 2.—Initial condition of three even-aged 

stands used for the simulations.

Stand BA/acre Number/

acrea DMb Relative density

Percent

1 105 304 10.4 103

2 121 594 10.7 92

3 106 484 11.0 104

a

Trees ≥1.0 inches d.b.h. b

The diameter at the midpoint of the distribution of 

basal area, for trees ≥6 inches d.b.h.

Table 3.—Comparison of sawtimber volume production between 

simulated diameter-limit cutting and crown thinning in three evenaged northern hardwood stands.

Stand 1 D-limit Thinning

Entry Cut Left Cut Left

(Bdft/ac) (Bdft/ac)

1st 3,264 0 593 2,671

2nd 2,872 0 1,055 6,109

3rd 3,427 0 10,788 0

All 9,563 12,436a

a

1.30 times more sawtimber, plus pulpwood of 11.4 cds, 7.6 cds, and 21.0 cds for 

the three successive entries.

Stand 2 D-limit Thinning 

Entry Cut Left Cut Left

(Bdft/ac) (Bdft/ac)

1st 4.874 0 1,039 3,835

2nd 3,523 0 2,034 7,442

3rd 4,784 0 13,044 0

All 13,181 16,117 b

b

1.22 times more sawtimber, plus pulpwood of 11.1 cds, 7.5 cds, and 2.7 cds for 

the three successive entries.

Stand 3 D-limit Thinning

Entry Cut Left Cut Left

(Bdft/ac) (Bdft/ac)

1st 4,787 0 1,056 3,730

2nd 2,990 0 2,462 6,223

3rd 3,534 0 10,496 0

All 11,311 14,014c

c

1.24 times more sawtimber, plus pulpwood of 9.7 cds, 3.5 cds, and 4.3 cds for the 

three successive entries.
19

indicating a need for landowners to choose 

between higher total cash flow from silviculture, 

or a higher discounted present worth of that 

revenue when the alternate rate of return exceeds 

4% (real rate of return).

Key Considerations for Unevenaged Stands

Uneven-aged stands have three or more age 

classes, with both the heights and diameters 

of trees related to their ages. Within each age 

class, some trees grow better than others. Yet 

available evidence (Eyre and Zillgitt 1953; Mader 

and Nyland 1984) shows that selection system 

cutting generally stimulates the growth of trees 

in all diameter classes, with greater absolute 

increases among the saplings and poles than for 

larger trees when the treatment reduces stand 

density to moderate or lower levels of stocking. 

Selection cutting removes the mature age class 

(generally specified by a threshold maximum 

diameter for the residual stand) to promote the 

regeneration of a replacement cohort. It also 

thins the immature age classes to leave specified 

numbers of each diameter (Nyland 1998), 

usually to conform to a structural guides like 

that proposed by Eyre and Zillgitt (1953) and 

Arbogast (1957) for northern hardwoods. The 

tending removes trees of the poorest quality and 

vigor, thereby upgrading the growing stock. By 

contrast, diameter-limit cutting simply removes 

all trees larger than some specified size. It does no 

tending of the immature age classes, nor does it 

control spacing and stocking levels to optimize 

growth and production.

Past simulation studies of uneven-aged 

silviculture in northern hardwoods showed the 

importance of matching the cutting interval 

to the level of residual stocking (Hansen and Nyland 

1987). Time must allow sufficient regrowth to replenish 

the volume. Also, cutting optimizes sawtimber volume 

production when it balances the age classes, generally by 

removing excess trees from the immature classes (cutting 

back to the target residual diameter distribution as noted 

Table 4.—Comparison of sawtimber value realized from 

simulated diameter-limit cutting and crown thinning in three 

even-aged northern hardwood stands.

Stand 1 D-limit Thinning

Entry Cut Left Cut Left

(Dollars/ac) (Dollars/ac)

1st 1,823 0 271 1,552

2nd 1,168 0 588 4,034

3rd 1,396 0 7,925 0

Total 4,387 8,784a

a

2.00 times more sawtimber revenue, plus $240 from sale of pulpwood 

(@$6/cd).

Stand 2 D-limit Thinning

Entry Cut Left Cut Left

(Dollars/ac) (Dollars/ac)

1st 2,665 0 585 2,080

2nd 1,577 0 1,306 4,902

3rd 2,202 0 9,638 0

Total 6,444 11,529b

b

1.79 times more sawtimber revenues, plus $128 from sale of pulpwood 

(@$6/cd).

Stand 3 D-limit Thinning

Entry Cut Left Cut Left

(Dollars/ac) (Dollars/ac)

1st 2,620 0 496 2,124

2nd 1,363 0 1,149 4,392

3rd 1,623 0 7,864 0

Total 5,606 9,857c

c

1.76 times more sawtimber revenue, plus $105 from sale of pulpwood 

(@$6/cd).

above). Taking these steps also insures consistency in the 

structural conditions through time (Hansen and Nyland 

1987), and in volume production through multiple 

entries to a stand (Nyland 1998).
20

Effect of Diameter-Limit Cutting on 

Long-term Timber Production and 

Value from Uneven-aged Stands

For the assessment of similarities and differences 

between selection system and diameter-limit 

cutting, I used the uneven-aged stand simulator 

by Hansen (see Hansen and Nyland 1984). The 

simulations included three real uneven-aged stands 

that had received a single diameter-limit cut, and 

three others following a single selection system 

cutting as described above (see Nyland 2005). 

Simulations started with the observed post-cutting 

diameter distribution (1-in. classes) for each 

stand. Then I grew them until stocking increased 

sufficiently for a second entry. Thereafter, I 

simulated the original cutting strategy over 

multiple entries at the designated interval for a 90- 

to 100-year period of time. 

Diameter-limit cutting removed all trees ≥14 in. dbh 

from two stands, and ≥16 in. in one other. The selection 

system cutting used 23 in. as the diameter for financial 

maturity, and reduced overall stocking to 75-80 ft2/ac. 

The simulator accounted for ingrowth of new age classes, 

and mortality as appropriate. Growth rates reflected 

changes previously observed in partially cut uneven-aged 

northern hardwood stands (Hansen and Nyland 1987).

Table 5 shows the sawtimber yields from each stand, and 

Table 6 the associated stumpage values. These reflect the 

volume harvested during the 90- to 100-yr periods, plus 

that in the residual stand after the last entry. Volume 

data indicate that selection system resulted in 91 to 93% 

of the volume coming from trees ≥16 in dbh (potentially 

Grade 1). The diameter-limit stands yielded 41%, 60%, 

and 89%, respectively, from trees of that size. That 

affected the realized values. A comparison of the diameter 

distributions across stands indicated that differences 

in yields associated with each cutting treatment reflect 

their structural attributes of the stands, and particularly 

in the abundance or shortage of poles that moved into 

sawtimber status during each cutting cycle. The third 

diameter-limit stand had large numbers of small trees, 

and their movement out of the pole class sustained a 

higher level of sawtimber production than in the other 

two diameter-limit cases. Selection system Stands A and B 

had initial deficiencies in the pole classes, and the limited 

number that moved out of pole size kept ingrowth to 

sawtimber below the level observed for Stand C.

Differences in cutting cycle lengths between stands 

complicates any comparison across treatments. But Table 

7 converts the production to annualized values. It shows 

that selection system resulted in an average production 

of 52 bdft/ac/yr more than the diameter-limit cuts, with 

Table 5.—Comparison of sawtimber volume production 

between simulated diameter-limit cutting and selection in 

uneven-aged northern hardwood stands (after Nyland 2005).

Realized yield (board feet/acre)a

Stand Total

years

Cutting

interval

Total From trees

16”+

% 

16”+

D-14b 100 20 26,284 10,718 41

D-16 100 2519,503 11,656 60

D-14 90 3018,465 16,450 89

Sel A 90 1523,618 21,412 91

Sel B 90 1523,671 22,079 93

Sel C 90 1526,454 24,277 92

a

For entire simulated time, including ending residual stand.

b

D-14 took all trees ≥14 inches d.b.h., and D-16 those ≥16 inches d.b.h.

Table 6.—Comparison of value realized between 

simulated diameter-limit cutting and selection 

in uneven-aged northern hardwood stands (after 

Nyland 2005).

Realized valueb

Stand Total

years

Cutting

interval

Total

D-14 100 20 yrs $11,173

D-16 100 25 yrs $11,713

D-14 90 30 yrs $12,913

Sel A 90 15 yrs $15,268

Sel B 90 15 yrs $15,588

Sel C 90 15 yrs $17,070

a

D-14 took all trees ≥14 in. dbh, and D-16 those ≥16 in. dbh.

b

For entire simulated time, including ending residual stand.
21

a $53/ac higher annual value growth. The 

simulations also showed more consistent 

levels of annual volume and value 

production across three selection system 

stands than following diameter-limit 

cutting. Harvest revenues discounted to the 

beginning of the 90- to 100-yr simulation 

period (at 4%, 6%, and 8% rates of 

interest) had positive PNW values from 

both strategies. For all rates, the diameterlimit cutting had a lower PNW. This 

mimics the higher century-long revenues 

from stands treated by selection system.

Similarities and Differences

None of the simulations accounted for 

losses of trees broken off during logging, 

or variations in tree growth associated 

with uniform or patchy spacing between 

residual trees. For the even-aged stands, I 

assumed that trees starting off in poor crown positions 

would increase in vigor as they grew larger, and radial 

increment would also increase accordingly. For the 

uneven-aged stands, I assumed that trees left after 

both types of cutting would provide adequate seed to 

regenerate a new cohort of desirable species following 

each entry, and that cutting would stimulate the growth 

of trees equally after diameter-limit and selection system 

cutting. For both stand types, I assumed that trees 

would have the highest grade for their diameter, and that 

neither epicormic branching or damage from logging 

or other causes would affect their value. Stumpage 

prices reflect the value realized by removing the entire 

sawtimber portion of a felled tree (stump height to a 

8-inch top diameter as specified in the volume table), 

and assumes that all trees have no scaling deductions. 

These assumptions simplified comparisons across cutting 

strategies.

Findings from the simulations indicate that an initial 

diameter-limit cutting in the simulated even-aged stands 

(removing all trees ≥12 in. dbh) took out 4.5 to 5.5 

times more sawtimber volume, and that resulted in 4 to 

5 times more first-entry revenues. For the entire rotation 

(three entries), diameter-limit cutting yielded only about 

80% as much volume as crown thinning, with only 9% 

to 14% of it from high-value trees (≥16 in. dbh). For 

these even-aged stands, it generated only 50% to 55% 

of the long-term revenues realized from the silvicultural 

systems employing crown thinning. Discounted harvest 

values from both strategies had a positive PNW at 4%, 

6%, and 8% rates of interest (the range tested).

For the simulated uneven-aged northern hardwood 

stands, diameter-limit cutting that removed trees ≥14 

or ≥16 in. dbh took out more volume and generated 

more harvest revenues during the first entry. Each 

diameter-limit cutting also left less residual volume, with 

stands having only 4 to 34% as much residual growing 

stock value as the selection system examples. For the 

90- to 100-year simulation periods, diameter-limit 

cutting resulted in about 80% of the volume realized by 

selection system silviculture, including 1.5 to 2 times 

less yield from high-value sawtimber trees (≥16 in. dbh). 

Annualized revenues were only 70% of that from the 

simulated selection system stands. Discounted values 

(harvested, plus residual following the last cutting) from 

both strategies had a positive PNW at 4%, 6%, and 8% 

rates of interest (the range tested).

Table 7.—Comparison of annualized sawtimber and value 

production between simulated diameter-limit cutting and selection 

in uneven-aged northern hardwood stands (after Nyland 2005).

Stand Total

years

Cutting

interval

Annualized productiona

Bdft Dollars

D-14 100 20 yrs 263 112

D-16 100 25 yrs 195 117

D-14 90 30 yrs 205 143

Average 221 124

SD 36.7 16.6

Sel A 90 15 yrs 262 169

Sel B 90 15 yrs 263 173

Sel C 90 15 yrs 294 190

Average 273 177

SD 18.2 11.2

a

Harvested plus that left standing after last cutting.
22

Overall, the simulations indicated that diameter-limit 

cutting over multiple entries (each time removing all 

trees ≥12 in. dbh from the even-aged stands, and those 

at least 14 or 16 in. from uneven-aged ones) will result 

in less realized sawtimber volume, fewer large-diameter 

sawlogs, and lower long-term revenues. Based on the 

higher sawtimber volume initially taken from a stand, 

diameter-limit cutting will prove more lucrative with the 

first entry into both stand types, but particularly when it 

removes all the sawtimber trees from even-aged stands at 

intermediate stages of development. Coupling the yield 

from excess pulpwood- and sawtimber-size trees will 

make crown thinning in even-aged stands commercially 

feasible. As long-term strategies, both approaches should 

have a positive PNW for interest rates of 4% through 8% 

(the range tested) when used in both even- and unevenaged stands, at least under the conditions simulated 

for this comparison. Among uneven-aged northern 

hardwoods, selection system silviculture will give more 

consistent yields and values across stands. For both evenand uneven-aged stands, silviculture will provide a higher 

cash flow over the long run.

The simulations did not assess the ecologic effects of 

either cutting strategy, or the ways they influenced an 

array of non-market values. Yet users normally promote 

diameter-limit cutting based on the perceived advantage 

it has for providing greater harvest volume and higher 

revenues. The simulations reported here indicate that the 

long-term benefits from silviculture exceed the shortterm gains from diameter-limit cutting, both in evenand uneven-age northern hardwood stands. That makes 

silviculture preferable for long-term sustainable forestry.

Literature Cited

Arbogast, C., Jr. 1957. Marking guide for northern 

hardwoods under the selection system. Stn. Pap. 56. 

St. Paul, MN: U.S. Department of Agriculture, Forest 

Service, Lake States Forest Experiment Station.

Eyre, F.H.; Zillgitt, W.H. 1953. Partial cuttings in 

northern hardwoods of the Lake States. Tech. Bull. 

1076. St. Paul, MN: U.S. Department of Agriculture, 

Forest Service, Lake States Forest Experiment Station.

Fajvan, M.A.; Grushecky, S.T.; Hassler, C.C. 1998. 

The effects of timber harvesting practices on West 

Virginia’s wood supply. Journal of Forestry. 96(5): 

33-39.

Hansen, G.D.; Nyland, R.D. 1987. Effects of diameter 

distribution on the growth of simulated unevenaged sugar maple stands. Canadian Journal of Forest 

Research. 17(1): 1-8.

Leak, W.B. 1999. Stand structure in evenaged northern 

hardwoods: Development and silvicultural 

implications. Northern Journal of Applied Forestry. 

16(2): 115-119.

Mader, S.F.; Nyland, R.D. 1984. Six-year responses of 

northern hardwoods to selection system. Northern 

Journal of Applied Forestry. 1: 87-91.

Marquis, D.A. 1991. Independent effects and 

interactions of stand diameter, tree diameter, crown 

class, and age on tree growth in mixed-species 

even-aged hardwood stands. In: McCormick, L.H.; 

Gottshalk, K.W., eds. Proceedings of the eighth central 

hardwood forest conference. Gen. Tech. Rep. NE-148. 

Radnor, PA: U.S. Department of Agriculture, Forest 

Service, Northeastern Forest Experiment Station: 442-

458

Marquis, D.A., ed. 1994. Quantitative silviculture 

for hardwood forests of the Alleghenies. Gen. 

Tech. Rep. NE-183. Radnor, PA: U.S. Department 

of Agriculture, Forest Service, Northeastern Forest 

Experiment Station.

Marquis, D.A.; Ernst, R.L.; Stout, S.L. 1992. 

Prescribing silvicultural treatments in hardwood 

stands of the Alleghenies (revised). Gen. Tech. Rep. 

NE-96. Radnor, PA: U.S. Department of Agriculture, 

Forest Service, Northeastern Forest Experiment 

Station.

Nyland, RD. 1992. Exploitation and greed in eastern 

hardwood forests. Journal of Forestry. 90(1): 33-37.
23

Nyland, R.D. 1998. Selection system in northern 

hardwoods. Journal of Forestry. 96(7): 18-21.

Nyland, R.D. 2000. Forestry and silviculture in the 

Northeast – past, present, and the probable future.

In: Proceedings of the Society of American Foresters 

national convention; Washington, D.C. Bethesda, 

MD: Society of american Foresters: 319-325.

Nyland, R.D. 2005. Diameter-limit cutting and 

silviculture: a comparison of long-term yields 

and values for uneven-aged sugar maple stands.

Northern Journal of Applied Forestry. 22(2): 111-116.

Nyland, R.D.; Alban, L.M.; Nissen, R.L., Jr. 1993. 

Greed and sustention: silviculture or not. In: Briggs, 

R.D.; Krohn, E.B., eds. Nurturing the northeastern 

forest. proceedings of a joint meeting of the New 

England Society of American Foresters and the Maine 

Wildlife Society;1993 March 3-5; Portland, ME. 

Misc. Rep. 382. Orono, ME: Maine Agriculture and 

Forest Experiment Station: 37-52.

Pell, J.A. 1998. Variables characterizing timber 

resource sustainability of recently harvested 

tracts across Pennsylvania. University Park, PA: 

Pennsylvania State University. M.S. thesis.
24

Overview of USDA Forest Service Research on Diameter-Limit 

Cutting in Northern Conifers

Laura S. Kenefic, John C. Brissette, and Paul E. Sendak

USDA Forest Service, Northeastern Research Station, Bradley, ME, and Durham, NH

hardwoods such as the maple (Acer spp.), birch (Betula

spp.), and aspen (Populus spp.).

Stand Development and Structure

Before addressing the specifics of the PEF study, 

it is important to review basic principles of stand 

development as they are relevant to our findings. In 

even-aged stands of single species, different heightgrowth rates result from genetics, microsite, or vigor, 

causing trees to differentiate into crown classes (Fig. 1). 

These classes (dominant, codominant, intermediate, 

and overtopped) indicate potential for future growth. 

For example, one would not expect an overtopped tree 

to grow as well as a dominant even if released (Marquis 

1991; Nyland et al. 1993). The effect of diameter-limit 

cutting in stands of this type is easy to grasp: the best 

growing stock is removed.

Even-aged stands of mixed species can form a more 

complicated structure. Even though all of the trees are 

the same age, different species have different growth 

rates. Faster growing, shade-intolerant species form 

upper layers or strata, while slower growing, more shadetolerant species form lower layers (Fig. 2). Within each 

layer, trees differentiate into crown classes indicative of 

their growth potential. In these stratified mixed-species 

Introduction

Partial cutting has become prevalent in the Northeast 

in recent years in response to public dissatisfaction with 

even-age regeneration methods and concerns about 

retaining trees for biodiversity conservation. Removals 

based on diameter limits are common. Diameter-limit 

cutting has been defined as the removal of trees above a 

specified size threshold (Helms 1998), usually without 

tending the smaller size classes (Kenefic and Nyland 

2005). In practice, unmerchantable timber is commonly 

left, resulting in high-grading, i.e., taking only the 

best trees from a stand. Because diameter-limit cutting 

is widespread, it is important to explore long-term 

implications for sustainability. Experimental applications 

of diameter-limit cutting, though rare, provide 

compelling data about treatment effects. The Penobscot 

Experimental Forest (PEF) in Maine is the site of one 

such experiment.

Penobscot Experimental Forest 

The 4,000-acre PEF is located in the towns of Bradley 

and Eddington in east-central Maine. The forest 

was purchased by nine industrial and land-holding 

companies and leased to the USDA Forest Service in 

1950 for a long-term experiment in silviculture. The first 

experimental treatment was applied in 1952. Although 

the property was transferred to the University of Maine 

in 1994, the Northeastern Research Station retains 

control of the experiment and continues the study 

today. The experiment has yielded more than 50 years 

of data on northern conifer silviculture and exploitative 

treatments.

The PEF is located in the Acadian Forest. An ecotone 

between the eastern broadleaf and boreal forests, the 

Forest is characterized by species and structural diversity. 

Common species include spruce (Picea spp.), balsam 

fir (Abies balsamea (L.) Mill.), eastern hemlock (Tsuga 

canadensis (L.) Carr.), northern white-cedar (Thuja 

occidentalis L.), eastern white pine (Pinus strobus L.), and 

Figure 1.—Trees differentiate into crown classes in evenaged stands of single species. Hash markets indicate trees 

removed in diameter-limit cutting.
25

stands, diameter-limit cutting might remove the better 

trees of the upper stratum species or the entire upper 

stratum, resulting in simplification of species diversity.

Multi-aged (uneven-aged) stands are different. In this 

case, a single species stand has different layers (strata) 

composed of different age classes (Fig. 3). There are 

crown classes within each age class. The effect of 

diameter-limit cutting is more complex. Within age 

classes, diameter-limit cutting might remove the most 

vigorous trees but vigorous younger trees remain in the 

stand.

A more complicated dynamic is found in stratified 

mixed-species, multi-aged stands, which are common in 

the northern conifer forest of the Acadian region. Such 

stands often contain mid- to shade-tolerant species that 

form a complex structure in which strata are composed 

of both different age classes and different species (Fig. 

4). Individual tree species are found in many canopy 

layers and age classes; there still are crown classes within 

strata. Within an age class, the fastest growing species, or 

the most vigorous trees, might be removed by diameterlimit cutting. Removals of trees from lower strata might 

include slow-growing trees from older age classes but also 

the fastest growing trees from younger age classes. This 

structure, which is found in several PEF stands, limits our 

ability to accurately predict the effect of diameter-limit 

cutting.

The PEF Experiment

The long-term silviculture experiment on the PEF 

includes 10 treatments, each applied to two stand 

replicates averaging 20 acres in size. The treatment 

stands were designated as geometric compartments 

(management units) without consideration of natural 

stand boundaries. Within-replicate and within-treatment 

variability are high for most measurement variables 

(Brissette 1996; Kenefic et al. 2005a). Treatments include 

even-age (two- and three-stage shelterwood with and 

without precommercial and commercial thinning) and 

uneven-age (5-, 10- and 20-year selection) systems, as 

well as exploitative (removal driven) practices such as 

commercial clearcutting, i.e., unregulated harvest, and 

fixed (inflexible) and modified (flexible) diameter-limit 

cutting (see Sendak et al. 2003).

Figure 2.—Mixed-species, even-aged stands have a stratified 

structure, with crown classes occurring within individual 

layers. Hash markets indicate trees removed in diameter-limit 

cutting.

Figure 3.—Multi-aged stands of a single species have 

strata composed of different age classes, with differentiation 

occurring within each layer. Hash markets indicate trees 

removed in diameter-limit cutting.

Figure 4.—Mixed-species, multi-aged stands have a complex 

structure. Different age classes and species form multiple 

strata, with differentiation into crown classes within each. 

Hash markets indicate trees removed in diameter-limit cutting.
26

Data are collected on a permanent plot network consisting 

of nested 1/5-, 1/20-, and 1/50-acre plots, covering 

approximately 15 percent of the treatment area. All trees ≥

0.5, 2.5, and 4.5 inches in diameter at breast height (dbh, 

4.5 feet) are measured on these plots, respectively. Species, 

dbh and condition (merchantability) have been recorded 

before and after every treatment and at 5-year intervals 

between treatments since the study began. Individual 

trees ≥ 0.5 inch dbh have been numbered since the 1970s. 

Regeneration data also have been collected since the 1960s 

on three milacre plots located at the periphery of each 

1/20-acre plot. Species and height class are recorded for 

seedlings 0.5 feet tall to 0.5 inch dbh.

The length of treatment and consistency of data 

collection in the PEF experiment are unusual, and allow a 

comprehensive long-term comparison of alternatives (see 

Kenefic et al. 2005b for additional examples). The 20-year 

selection and fixed diameter-limit cutting are particularly 

well-suited for comparison. There were no pretreatment 

differences in composition or structure between the 

stands, and a similar harvest interval facilitates analysis 

(Kenefic et al. 2005c). The focus of this report is on those 

two treatments.

Pretreatment Forest History

Researchers took photographs of the study area before 

the experiment was initiated. The photos show an 

irregular forest structure with significant components of 

mature softwood-dominated mixed-species stands in the 

understory reinitiation phase of stand development (Fig. 

5). Although there had been no harvesting during the 

50 years prior to the establishment of the Forest Service 

experiment, stand reconstruction data suggest that the 

forest had been partially cut repeatedly before the 20th 

century. There is some evidence of fire on the forest 

after early harvests of white pine, but the study area does 

not appear to have been cleared or burned extensively 

(Safford et al. 1969). Trees more than 150 years old at 

breast height are common in the study area (Kenefic and 

Seymour 1997; Seymour and Kenefic 1998), and some 

individual trees are more than 200 years old at breast 

height (unpublished data).

Figure 5.—Pretreatment photos from the 1950s suggest that the PEF was 

a mixed-species, conifer-dominated forest with irregular stand structures.
27

Treatments

Selection Cutting—The selection stands have been 

managed using a mathematically defined BDq structural 

goal with a target residual basal area (BA, trees ≥ 0.5 

inches dbh) of 80 ft2/acre, maximum residual dbh of 16 

inches, and q-factor of 1.4 on 1-inch dbh classes (1.96 

on 2-inch classes). Allowable cut is determined as the 

difference between pretreatment BA and posttreatment 

goal, and is distributed based on the target diameter 

distribution and marking and species composition 

guidelines. The marking guidelines are intended to 

improve residual stand quality, growth, and composition. 

In order of priority, we remove cull trees (stems > 50 

percent unmerchantable by volume), high-risk and 

low-vigor trees, undesirable species, and trees at financial 

maturity (target maximum value). Crop trees are released 

and regeneration openings are created or enlarged. The 

regeneration method is a combination of single-tree and 

small-group selection.

Species preferences further guide removals, with BA 

goals of 35 to 55 percent for spruce, 15 to 25 percent 

each for balsam fir and hemlock, and 5 to 10 percent 

each for eastern white pine, paper birch, cedar and other. 

Because the percentage of spruce generally is less than 

this goal and the percentages of fir and hemlock are 

higher than the goals, we have discriminated against fir 

and hemlock and attempted to retain and release spruce. 

(Stand structural and compositional goals currently are in 

revision.)

Diameter-Limit Cutting—The fixed diameter-limit 

treatment uses thresholds for species removal as follows: 

11 inches dbh for white pine, 9 inches for spruce and 

hemlock, 8 inches for paper birch and cedar, and all 

merchantable fir and other species. Over the study 

period these thresholds have varied by ± 1.0 inch, and 

the lower level of merchantability dropped from 6.5 to 

4.5 inches dbh. All trees above the diameter limits except 

cull are removed and all trees below the diameter limits 

are retained. The study plan specifies that the stands are 

to be reentered when merchantable volume above the 

diameter limits equals that previously removed. For the 

three harvests conducted to date, this has resulted in a 20-

year harvest interval coincident with the 20-year selection 

(note that the third cut in one of the diameter-limit 

replicates was delayed by five years due to slower volume 

regrowth).

Treatment Comparison

Kenefic et al. (2005c) reported the results of a 

comprehensive analysis of the 20-year selection and fixed 

diameter-limit treatments. Highlights of those findings 

are presented here. 

Comparison of pretreatment stand conditions revealed 

no differences (significance level = 0.10) in volume 

(ft3/acre) (p = 0.82), number of trees by size class (p 

= 0.76 to 0.86), or species composition (p = 0.14 to 

0.61) between the two treatments. Three harvests were 

subsequently applied in the 1950s, 1970s, and 1990s 

(Fig. 6). A comparison of stand structure after the most 

recent harvest revealed significant differences between 

0

1

10

100

1000

Number of trees/acre

0 2 4 6 8 10 12 14 16 18 20 22 24

Dbh (inches) Goal Post Cut #1

Post Cut #2 Post Cut #3

Selection

0

1

10

100

1000

Number of trees/acre

0 2 4 6 8 10 12 14 16 18 20

Dbh (inches)

Post Cut #1 Post Cut #2 Post Cut #3

Diameter Limit

Figure 6.—Diameter distributions of the selection and 

diameter-limit cut treatments after each of the three 

harvests on the PEF.
28

treatments; there were fewer trees in the small and 

medium–large sawtimber classes of the diameter-limit 

stands (p = 0.04 and 0.01, respectively). Harvest volume 

in the two treatments for the three harvests combined 

suggested that more volume was removed in diameterlimit cut stands (3,527 ft3

/acre) than the selection 

stands (2,518 ft3

/acre), though the difference was not 

statistically significant (p = 0.14). However, net actual 

harvest value discounted to year 0 at 4 percent was higher 

in the diameter-limit treatment ($774/acre versus $428/

acre in the selection treatment) (p = 0.04).

At first assessment, the value of the harvests make the 

diameter-limit treatment appealing. However, the 

focus of silviculture is residual stand condition, so what 

was removed is less important than what was left. The 

value of the standing inventory after the third harvest 

was nearly 8 times greater in the selection than fixed 

diameter-limit treatments ($59/acre versus $409/acre) (p 

= 0.10). Interestingly, when we combined harvest value 

with residual inventory value to obtain the accumulated 

value, there was no difference between treatments (p = 

0.98) (Fig. 7). This accumulated value index suggests no 

financial benefit associated with diameter-limit cutting 

over the approximately 45-year measurement period. 

However, data from the residual stands raise concerns 

about the impacts of the diameter-limit treatment.

Although neither total (gross) growth nor mortality 

were differentiated by treatment (p = 0.31 and 0.77), 

ingrowth was significantly greater in the diameter-limit 

stands (10.6 ft3

/acre/year versus 6.9 ft3/acre/year in the 

selection stands) (p = 0.03). Diameter-limit cutting 

removed the largest trees with the largest crowns, and 

reduced growing stock to a lower level than the selection 

treatment. The lower strata of the diameter-limit stands 

were released and the amount of ingrowth (trees growing 

from sapling to merchantable size) increased. Thus, 

growth was concentrated on smaller trees (Fig. 8); in 

the selection stands, the proportion of net growth was 

greatest on trees > 12 inches dbh, i.e., the most valuable 

trees in the stand. 

The long-term impact of cutting only large trees and 

concentrating growth on small trees is apparent when 

value per harvested tree is analyzed. Revenue generated 

per tree in the first cut was similar between treatments, 

with an average value of $2.07 per tree in the selection 

treatment versus $2.99 in the diameter-limit treatment 

(determined as gross harvest revenue; calculated in 

1982 dollars using nominal prices adjusted by the all 

commodity Producer Price Index, divided by number 

of trees cut). However, in the third cut, the value of 

individual harvested trees in the diameter-limit treatment 

($1.73) was less than half that in the selection treatment 

($4.04). This suggests a trend of diminishing individualtree value that accounts for lower total stand value, 

and further suggests reduced efficiency of harvesting 

operations because more trees must be cut to generate 

the same amount of revenue. The impact on harvest 

Figure 7.—Accumulated value per acre (harvest 

plus residual) in the selection and diameter-limit cut 

treatments after three harvests on the PEF.

Figure 8.—Distribution of net growth among tree 

size classes in the selection and diameter-limit cut 

treatments on the PEF.
29

revenue likely is even more pronounced in hardwood 

stands where improvements in tree grade associated with 

large and good-quality trees add exponentially to value. 

Grade is not a consideration for the dominant softwood 

species (hemlock, fir, and spruce) on the PEF, so the 

effect of reduced maximum diameter and tree quality on 

revenues was mitigated somewhat by an increased harvest 

volume in the smaller classes.

Species composition also was affected differently by the 

two treatments. Spruce and fir are common associates in 

the northern conifer forest. They often occur together 

but management recommendations usually favor spruce 

due to its potential greater value, longer life span, and 

larger size. Shorter lived and prone to decay on poor 

sites, fir also is the preferred host of spruce budworm 

(Choristoneura fumiferana Clemens), which causes growth 

suppression and mortality during periodic outbreaks. 

One metric of compositional improvement is the ratio 

of spruce to fir. Ratios > 1 indicate more spruce than fir 

while those < 1 occur when fir is the dominant species. 

Prior to treatment, the spruce: fir ratio was 0.9 in the 

selection stands and 1.4 in the diameter-limit stands. 

After three cuts, the ratio was improved to 2.1 in the 

selection treatment, but had deteriorated to 0.5 in the 

diameter-limit stands.

Questions have been raised about the influence of the 

diameter limits on the PEF results. If high diameter 

limits were used, would stand degradation still have 

occurred? The answer lies in our understanding of how 

trees grow and stands develop. Within any age class, the 

better growing trees are larger, so diameter-limit cutting 

continually downgrades the growing stock. In stratified 

stands, trees restricted to upper strata may be eliminated. 

Raising the diameter-limit might postpone these effects 

but would not prevent their occurrence. This finding is 

supported by Sokol et al. (2004), who discovered that 

residual spruce in the PEF diameter-limit cut stands were 

consistently smaller than trees of the same age in the 

selection stands, and that the diameter-limit residuals had 

been slower growing throughout their lives. This supports 

the conclusion that diameter-limit cutting removed the 

faster growing trees.

Unmerchantable timber amounted to > 25 percent 

of stand volume after three cuts in the diameterlimit treatment, but < 1 percent of total volume in 

the selection treatment (p = 0.03). Lower stocking, 

smaller mean diameter, and a greater proportion of 

unmerchantable timber account for lower residual value. 

Hawley et al. (2005) established that only two cuts 

resulted in significant differences in genetic diversity of 

hemlock (a dominant species) in the PEF selection and 

diameter-limit stands. They found a higher number 

of rare alleles, which they believed were related to 

undesirable traits, e.g., poor form, vigor, or growth, in 

the diameter-limit stands.

It is important to note that our results represent the 

cumulative effects of repeated diameter-limit and 

selection cuttings. In fact, treatment disparity has 

increased over time. A preliminary analysis of the effect 

of partial cutting alternatives on residual volume, percent 

cull, percent spruce, and sawtimber density revealed that 

there were no significant differences between treatments 

after the first cut (Kenefic et al. 2004). However, the 

magnitude of treatment differences increased over 

time, resulting in less sawtimber and more cull in the 

diameter-limit than selection cut after two treatments, 

as well as less total volume and less spruce after the third 

treatment. These findings underscore the fact that the 

effects of diameter-limit cutting may not be immediately 

apparent but that repeated applications and a long-term 

perspective highlight issues of concern. 

Conclusion

The concurrent presentation of results from the PEF 

in Maine and from Nyland’s research in northern 

hardwoods in New York (this proceedings) support the 

conclusion that diameter-limit cutting degrades stand 

condition over time, relative to initial stand condition 

and alternative silvicultural treatment. It is compelling 

that the results of the two studies are so similar (see 

Nyland 2005 and Kenefic et al. 2005c, and Kenefic and 

Nyland 2005). The fact that comparable treatments in 

two different forest types resulted in similar outcomes 

suggests that our findings are relevant to diameter-limit 

cutting with retention of culls in general, and not the 

specific treatment applied or study area investigated.
30

The publication of the results from the PEF represents 

the first quantification of the long-term effects of 

repeated diameter-limit cutting, and the benefits of 

silvicultural treatment. It is our hope that this research 

will help landowners and practitioners better understand 

the implications of different forms of partial cutting.

Literature Cited

Brissette, J.C. 1996. Effects of intensity and frequency 

of harvesting on abundance, stocking and 

composition of natural regeneration in the Acadian 

forest of eastern North America. Silva Fennica. 30(2-

3): 301–314.

Hawley, G.J; Schaberg, P.G.; DeHayes, D.H.; Brissette, 

J.C. 2005. Silviculture alters the genetic structure 

of an eastern hemlock forest in Maine. Canadian 

Journal of Forest Research. 35: 143-150.

Helms, J.A. 1998. The dictionary of forestry. Bethesda, 

MD: Society of American Foresters. 210 p.

Kenefic, L.S.; Brissette, J.C.; Sendak, P.E. 2004. The 

effects of alternative diameter-limit cutting 

treatments: some findings from a long-term 

northern conifer experiment. In: Proceedings 

of the 84th winter meeting of the New England 

Society of American Foresters. Gen. Tech. Rep. 

NE-314. Newtown Square, PA: U.S. Department of 

Agriculture, Forest Service, Northeastern Research 

Station: 22-24.

Kenefic, L.S.; Nyland, R.D. 2005. Diameter-limit 

cutting and silviculture in northeastern forests: a 

primer for landowners, practitioners, and policy 

makers. NA-TP-02-05. Newtown Square, PA: 

U.S. Department of Agriculture, Forest Service, 

Northeastern Area, State and Private Forestry. 18 p.

Kenefic, L.S.; Sendak, P.E.; Brissette, J.C. 2005c. 

Comparison of fixed diameter-limit and selection 

cutting in northern conifers. Northern Journal of 

Applied Forestry. 23: 77-84.

Kenefic, L.S.; Sendak, P.E.; Brissette, J.C. 2005b. 

Turning data into knowledge: USDA Forest Service 

research on the Penobscot Experimental Forest.

In: Irland, L., ed. Sustaining long term silvicultural 

research. Res. Rep. New Haven, CT: Yale University, 

Global Institute for Sustainable Forestry. (In press).

Kenefic, L.S.; Seymour, R.S. 1997. Patterns of tree 

growth and structural development in unevenaged northern conifer stands in the Acadian 

Forest of Maine. In: Proceedings of the IUFRO 

interdisciplinary uneven-aged management 

symposium; 1997 September 15-19; Corvallis, OR. 

[Place of publication unknown]: [Publisher name 

unknown]: 554-568.

Kenefic, L.S.; White, A.S.; Cutko, A.R.; Fraver, S. 2005a. 

References for silvicultural research: a Maine 

perspective. Journal of Forestry. 103(7): 363-367.

Marquis, D.A. 1991. Independent effects and 

interactions of stand diameter, tree diameter, crown 

class, and age on tree growth in mixed-species 

even-aged hardwood stands. In: McCormick, L.H.; 

Gottshalk, K.W., eds. Proceedings of the eighth central 

hardwood forest conference. Gen. Tech. Rep. NE-148. 

Radnor, PA: U.S. Department of Agriculture, Forest 

Service, Northeastern Forest Experiment Station: 442-

458.

Nyland, R.D. 2005. Diameter-limit cutting and 

silviculture: a comparison of long-term yields 

and values for uneven-aged sugar maple stands.

Northern Journal of Applied Forestry. 22: 111-116.

Nyland, R.D.; Alban, L.M.; Nissen, R.L., Jr. 1993. 

Greed or sustention: silviculture or not. In: Briggs, 

R.D.; Krohn, W.B., eds. Nurturing the northeastern 

forest. Misc. Rep. 382. Orono, ME: Maine 

Agricultural and Forest Experiment Station: 37-52.

Safford, L.O.; Frank, R.M.; Little, E.L., Jr. 1969. Trees 

and shrubs of the Penobscot Experimental Forest, 

Penobscot County, Maine. Res. Pap. NE-128. Upper 

Darby, PA: U.S. Department of Agriculture, Forest 

Service, Northeastern Forest Experiment Station. 27 p.
31

Sendak, P.E.; Brissette, J.C.; Frank, R.M. 2003. 

Silviculture affects composition, growth, and yield 

in mixed northern conifers: 40-year results from 

the Penobscot Experimental Forest. Canadian 

Journal of Forest Research. 33: 2116-2128.

Seymour, R.S.; Kenefic, L.S. 1998. Balance and 

sustainability in multi-aged stands: a northern 

conifer case study. Journal of Forestry. 96: 12-16. 

Sokol, K.A.; Greenwood, M.S.; Livingston, W.L. 2004. 

Impacts of long-term diameter-limit harvesting on 

residual stands of red spruce in Maine. Northern 

Journal of Applied Forestry. 21: 69-73.
32

Research on Diameter-Limit Cutting in Central 

Appalachian Forests

Mary Ann Fajvan

USDA Forest Service, Northeastern Research Station, Morgantown, WV

data). Forest sustainability also can be affected because 

the most vigorous overstory trees are removed during 

a diameter-limit harvest. Although trees in the 

intermediate crown class and understory trees receive 

more growing space, many of these low-vigor stems will 

die or grow slowly (Marquis and Ernst 1991). There 

also is a reduction in seed sources of high-value species 

that are selectively removed (high-graded) down to the 

smallest merchantable diameters. For example, in West 

Virginia, 36 percent of the harvests surveyed in 1995 

showed reductions of more than 80 percent in basal 

areas of northern red (Quercus rubra) and white oaks 

(Quercus alba), yellow-poplar (Liriodendron tulipifera), 

ash (Fraxinus Americana/Fraxinus pennsylvanica), and 

black cherry (Prunus serotina) (Fajvan et al. 1998). Such 

reductions have important implications for future timber 

supply, stand productivity, and economic returns available 

to landowners. Biodiversity and ecosystem resiliency 

also are affected as species are selectively removed during 

repeated partial harvesting (Schuler 2004).

Diameter-limit harvests (or any partial canopy removal 

harvest) are classified as minor disturbances (Oliver 

and Larson 1996) because some trees that predate the 

disturbance survive. These trees may increase in growth 

if they are healthy, have sufficient live crowns and are 

undamaged from logging. Alternatively, if the residual 

trees previously were in subordinate crown positions, 

their growth increase may be marginal, stem quality may 

be lost due to epicormic sprouting, or mortality can occur 

(Roach and Gingrich 1968). If sufficient growing space 

has been created by the harvest, regeneration may develop 

from new seedlings, advance regeneration, and sprouting.

In this paper I review past and current research on the 

effects of diameter-limit harvesting on the stand structure, 

productivity, regeneration, and overall sustainability of 

even-aged hardwood forests. Results of past monitoring 

studies in West Virginia, Pennsylvania, and New York are 

summarized, and new data are presented from long-term 

studies on the West Virginia University Forest.

Introduction

In their abundance and quality the mature, second-growth 

forests of the Central Appalachian region are a valuable 

timber resource for landowners, forest industries and the 

general public. As these forests are harvested, maintaining 

their productive capacity and conserving tree species 

diversity are important considerations for long-term 

sustainability according to the Montreal Process Criterion 

and Indicators (http://www.mpci.org/criteria_e.html). 

Current stands typically contain more than 20 tree species 

representing a range of silvical characteristics (Miller and 

Kochenderfer 1998; Brashears et al. 2004). As a result, 

establishing new cohorts with species representative of the 

forest that preceded them requires planned silvicultural 

treatments before harvest. Long-term silvicultural research 

has produced guidelines for sustainable management of 

these forests (e.g., Roach and Gingrich 1968; Smith and 

Eye 1986; Nyland 1987; Marquis et al. 1992) that are 

used widely on publicly owned lands in the region (USDA 

For. Serv. 1986).1

 However, these guidelines are rarely 

followed on most of the private land in this region or 

elsewhere in the Northeast (Fajvan et al. 1998; Pell 1998; 

unpublished data).

Because private nonindustrial forests account for 

nearly 80 percent of forest ownership in the Central 

Appalachians (Smith 1994), harvesting practices on these 

ownerships affect landscape attributes such as wildlife 

habitat, scenic quality, recreational opportunity, and 

economic value. Forest industry is the foundation to 

sustaining these values by making forest management 

economically feasible for landowners. Yet in 1995, 

assessments of timber harvesting practices conducted in 

three states suggested that these practices threaten the 

diverse supply of raw materials essential to support such 

an industry (Fajvan et al. 1998; Pell 1998; unpublished 

1

An evaluation of the Pennsylvania Department of 

Conservation and Natural Resources Bureau of Forestry under 

the SCS ConservationProgram (2005). Unpublished report 

available from the Pennsylvania Bureau of Forestry, Harrisburg.
33

Review of Research on Diameter-Limit 

Harvesting

1995 Timber Harvest Assessment

In 1995, scientists and managers in New York, 

Pennsylvania, and West Virginia examined postharvest 

stand attributes in an attempt to describe future forest 

sustainability. Ninety-nine harvests were sampled in 

West Virginia, and 99 and 62 harvests were sampled 

in Pennsylvania and New York, respectively. Following 

examination of pre- and postharvest stand structures, 

analyses focused on describing harvesting practices and 

resulting effects on sustainability. The studies confirmed 

that diameter-limit harvesting was practiced on about 

half of the harvests surveyed in New York (unpublished 

data) and Pennsylvania (Pell 1998), and on 80 percent 

of the harvests in West Virginia (Fajvan et al. 1998). The 

remaining harvests consisted of intermediate treatments 

such as thinnings, or regeneration harvests such as 

shelterwood seed cuts and clearcuts.

Regardless of harvesting practice, residual stand 

conditions in all three states were analyzed with respect to 

total stocking, stocking of commercially desirable species, 

and stem quality, to determine whether it still was feasible 

to manage for sawtimber in the current rotation. In New 

York and West Virginia, only 20-27 percent of harvests 

had desirable residual conditions. In Pennsylvania, 

about half of the harvests produced desirable conditions. 

Because diameter-limit harvesting does not take future 

stand condition into account, the typically irregular 

spatial distribution of residual trees can affect new cohort 

development and restrict future management options. In 

68 percent of the harvests surveyed in New York, cutting 

increased stocking variability by at least 1.5 times, i.e., 

the residual stand was more “patchy” than preharvest 

conditions. The distribution of regeneration also is 

irregular because the regeneration is concentrated in large 

gaps.

Effects of Diameter-Limit Cutting on 

Regeneration Composition and Density

In 1998 we revisited 86 of the sites from West Virginia’s 

1995 harvest assessment to measure regeneration 

characteristics as part of a collaborative effort by the West 

Virginia Sustainable Forestry Initiative Committee, West 

Virginia University, and the West Virginia Division of 

Forestry. Our objective was to create a model that uses 

stand-structure variables to predict regeneration density 

after harvesting. Forest ownerships ranged in size from 

20 to 5,000 acres but sampling occurred in harvested 

stands ≤ 150 acres. Fifteen, circular plots (1/20 acre) 

were established randomly in each stand to measure 

trees ≥ 1.0 inch at 4.5 feet above the ground (d.b.h.) and 

record percent cover of all other woody and herbaceous 

vegetation and exposed rocks. Three milacre plots were 

nested within each larger plot to measure new seedlings 

and sprouts < 1.0 inch d.b.h. and record the number of 

browsed seedlings.

Residual basal area averaged 58 ft2/acre statewide (range: 

0 to 152 ft2

/acre) and was dominated by red maple 

(Acer rubrum), yellow-poplar, and chestnut oak (Quercus 

prinus). Residual trees per acre were primarily red maple 

(17 percent), sugar maple (Acer saccharum) (16 percent), 

beech (Fagus grandifolia) (8 percent), yellow-poplar (6 

percent), and hickory (Carya sp.) and black gum (Nyssa 

sylvatica) (5 percent each). Except for American beech 

and chestnut oak, over 90 percent of regeneration was 

classified as new seedlings. Forty percent of the harvests 

were considered “adequately stocked” under the criteria 

of 5,000 to 10,000 seedlings per acre and 85 percent of 

milacre plots stocked with one or more stems ≥ 1 foot 

tall (Trimble 1973). Red maple was the most abundant 

species statewide, followed by yellow- poplar, which had 

the most seedlings > 3 feet tall (Table 1).

Table 1.—Seedling densities from 39 partial harvests 

(residual stocking < 50 percent) in West Virginia. 

Species

Mean seedlings/

acre

Percent seedlings 

> 3 ft tall

American beech 236 30

White oak 270 4

Hickory 341 7

Black cherry 408 23

Ash 410 13

Chestnut oak 443 5

Birch 491 14

Red/Black oaks 682 14

Sugar maple 686 14

Yellow-poplar 953 18

Red maple 2736 5
34

Only 39 stands were included in the regression analyses 

for modeling regeneration density. These were the 

stands that had < 50 percent stocking after harvest and 

were classified previously (Fajvan et al. 1998) as having 

sufficient growing space for regeneration establishment. 

Data on stand structure from the 1/20-acre plots were 

averaged for each stand. Independent variables in 

the regression model included preharvest basal area, 

preharvest trees per acre, residual basal area in each of 

three height classes (1 to 20, 20 to 50, and > 50 feet), 

total residual basal area, residual trees per acre, and 

percent basal area removed. Percent browsed seedlings 

and percent cover of other woody and herbaceous 

vegetation and exposed rocks were averaged from 

the milacre plots for each stand and also included as 

variables. The dependent variable was the number of 

seedlings per acre ≥ 1 foot tall.

Multiple regression was used to determine which 

independent variables explained the greatest amount of 

variation in the data and should be included in the final 

model. An adjusted coefficient of determination was used 

to evaluate each model. The final model had an adjusted 

R2 of 0.71 and included four variables that were most 

highly correlated with regeneration density:

Y = 7557.40 – 7.74*B1 – 44.25*B2 – 

118.99*B3 + 67.10*B4

where:

Y = Seedlings/acre ≥ 1 foot tall (commercial species)

B1 = Residual trees/acre

B2 = Percent cover of herbs 

B3 = Percent cover grass 

B4 = Residual basal area/acre for trees 20 to 50 feet tall

There was a negative relationship of seedling density with 

total residual trees per acre and percent cover of herbs 

and grass. However, number of seedlings was positively 

correlated with residual basal area of trees 20 to 50 feet 

tall, which included most of the residual overstory. Most 

trees taller than 50 feet probably were removed in the 

harvests. The “high shade” produced by this canopy may 

have had a positive effect on shade-tolerant red maple, 

which dominated the regeneration. Also, at the time of 

this study, the regeneration had developed only for 4 to 5 

years postharvest so perhaps insufficient time had elapsed 

for shading to have a negative effect on regeneration 

density.

Effects of Residual Trees on Regeneration 

Composition and Size

In 1993, four stands on the West Virginia University 

Forest in north-central West Virginia, were divided into 

three, 10-acre treatment blocks to receive a 12-inch 

diameter-limit harvest, a 16-inch diameter-limit harvest, 

or no harvest. The trees were about 60 years old. Stands 

were located on northern aspects, had average basal areas 

of 150 ft2

/acre, and were composed of yellow-poplar (50 

percent of basal area), northern red oak (30 percent) and 

lesser amounts of red maple, black cherry and white oaks. 

Residual basal areas in the 12-inch harvest ranged from 

10-30 ft2/acre and 30 to 60 ft2

/acre in the 16-inch harvest.

Regeneration composition was sampled prior to 

harvesting and annually for 5 years (Fig. 1), and again 

Figure 1.—Mean regeneration density 

(trees per acre) and species composition 

of seedlings > 20 inches tall 5 years after 

diameter-limit harvesting (uncut control, 16-

inch diameter limit, 12-inch diameter limit) 

on the West Virginia University Forest.

0

500

1000

1500

2000

Control D-limit (16 inch) D-limit (12 inch)

Harvest Treatment

Trees / acre

Cherry

Red maple

Red oak

Y-poplar

Sassafras
35

at 9 years (Fig. 2). After 5 years, the 12-inch harvests 

had more regeneration > 3 feet tall than the 16-inch 

diameter limit (2,307 ± 612 vs. 1,273 ± 387 trees per 

acre, respectively). The uncut stands had less regeneration 

(293 ± 166) than the harvested sites. The 12-inch 

harvests had the lowest residual basal areas partly because 

10 percent of the residual trees were destroyed during 

logging (Fajvan et al. 2002). These stands resembled 

clearcuts and had more sunlight and growing space to 

support higher regeneration densities than the 16-inch 

diameter-limit harvests. Regardless of treatment and time 

since harvest, black cherry was the most abundant species 

in the regeneration even though overstory black cherry 

represented only about 10 percent of the basal area before 

treatment. Black cherry also was the most abundant 

species of advance regeneration (see Fig. 1 Control) 

because it is not preferred as browse by white-tailed deer.

In 2003 we examined the effects of the residual trees in 

the 16-inch diameter-limit harvests on regeneration size 

and species composition to determine whether shading 

from the residual tree crowns affected the importance of 

shade-tolerant versus shade-intolerant species under tree 

crowns compared to the species composition of saplings 

in the gaps between crowns. A sample of 130 residual 

trees ranging in size from 7 to 17 inches d.b.h., were 

selected randomly from the four, 16-inch diameter-limit 

harvests proportional to their species’ and size (diameter) 

representation in the stand (Table 2). Yellow-poplar and 

red maple were the most abundant species with average 

heights ranging from 61 to 86 feet. These 130 trees were 

used as plot centers, and saplings (1 to 5 inches d.b.h.) 

were sampled on 5-foot-wide transects arranged along 0, 

90, 180 and 270 degree azimuths. Transects were variable 

Figure 2.—Mean regeneration density 

(trees per acre) and species composition of 

saplings 1 to 5 inches d.b.h., 9 years after 

diameter-limit harvesting (uncut control, 16-

inch diameter limit, 12-inch diameter limit) 

on the West Virginia University Forest.

0

200

400

600

800

1000

1200

1400

1600

1800

Control D-limit (16 inch) D-limit (12 inch)

Harvest Treatment

Trees / acre

Cherry

Red maple

Red oak

Y-poplar

Sassafras

Birch

Table 2.—Mean d.b.h., total height, live crown ratio, and crown projection areas 

of 130 residual trees measured 9 years after a 16-inch diameter limit harvest on the 

West Virginia University Forest (standard errors are in parenthesis).

Species

Number of 

trees D.b.h. Total height 

Live crown 

ratio

Crown projection 

area

inches feet ft2

Chestnut oak 10 13.6 (0.4) 86.2 (2.4) 47.4 (2.1) 358.2 (39.3)

Red maple 40 10.2 (0.3) 61.0 (1.9) 57.7 (1.2) 341.1 (21.5)

Red/black oak 30 14.4 (0.4) 80.9 (2.2) 56.0 (1.5) 393.1 (27.4)

White oak 10 11.2 (0.5) 78.6 (2.8) 45.2 (2.0) 275.5 (35.4)

Yellow-poplar 40 14.5 (0.3) 82.7 (1.9) 52.0 (1.4) 252.3 (15.8)
36

in length because they extended 5 feet beyond the crown 

edge in their respective direction.

Because of the irregular spacing among residual trees, 

some crowns of the plot center trees overlapped other 

residual trees in the vicinity. Thus, saplings could be 

located under two or three overlapping crowns. Sapling 

total height, diameter, crown class (relative to associated 

saplings), and their distance from the plot center tree 

were measured. Sapling data also were categorized 

according to their location relative to residual tree 

crowns: 1) under the center tree 2), outside the crown 

of the center tree 3), under the center tree and an 

overlapping crown(s) and 4) outside the crown of center 

tree but under the crown(s) of adjacent trees.

Preliminary results indicated that of the 2,239 saplings 

sampled, black cherry was the most abundant species 

(importance value = 0.37) followed by red maple 

(importance value = 0.15). Red/black oaks, black 

birch and yellow-poplar each had importance values 

around 0.10. Twelve percent of the saplings were in the 

dominant/codominant crown classes with black cherry 

accounting for 45 percent of these followed by red maple 

and black birch about 13 percent each. The mean height 

of red maple (17.3 feet ± 0.5 foot) was greater than that 

of black birch (16.8 feet ± 0.5 foot) and black cherry 

(16.3 feet ± 0.3 foot). The average height of red/black 

oaks (8.2 feet ± 0.5foot) was about 50 percent less than 

that of these other species.

Saplings growing outside the crown of the center tree 

were taller (16.5 feet ± 0.3 foot) than those growing 

under its crown (15.3 feet ± 0.2 foot) or under its crown 

and another crown (14.6 feet ± 0.6 foot) or under the 

crowns of one or more other residual trees along the 

transect (14.5 feet ± 0.7 foot). Basal area and mean total 

heights of dominant/codominant saplings also were 

greater outside the center tree crown (57.3 ± 3.9 ft2, 26.4 

feet ± 0.6 foot) than under its crown (28.6 ± 2.4 ft2, 24.7 

feet ± 0.4 foot), or under its crown and another crown 

(12.7 ± 4.9 ft2

, 20.4 feet ± 1.3 foot), or under the crowns 

of other trees along the transect (53.1 ± 12.1 ft2

, 20.9 feet 

± 1.02 foot).

Discussion

The studies discussed here expand our knowledge about 

the effects of partial cutting on stand structure, but this 

information does not alter our basic understanding of 

stand dynamics and minor disturbances. For example, 

Roach and Gingrich (1968) described residual stands 

resulting from past (partial) “overcutting” as having an 

“irregular crown canopy” with residual mature trees that 

generally “will deteriorate in quality” and with “desirable 

reproduction that will not develop properly.” They 

observed that desirable (shade-tolerant) regeneration 

probably is present if stand stocking is below the Clevel, but that it would eventually be overtopped by 

a less desirable “understory of tolerant brush.” They 

recommended that the overstory be removed as soon as 

possible before residual tree quality deteriorated further 

and to favor growth of desirable (shade-intolerant) 

regeneration. Although timber markets have changed 

during the past 40 years, exploitative harvesting practices 

have not. The 1995 West Virginia harvest assessment and 

subsequent regeneration survey indicated that shadeintolerant, high-value species are favored removals in 

the harvests and that shade-tolerant maples and beech 

dominated the residual stands. Even though the tallest 

species of regeneration was shade-intolerant yellowpoplar 4 to 5 years after harvest, the density of red maple 

was nearly three times greater.

Another study on the West Virginia University Forest 

indicated that after clearcutting, red maple had slower 

height growth than yellow-poplar and black cherry but 

could grow as fast as red oak to eventually occupy a 

codominant crown position in the overstory with oak 

and poplar (Tift and Fajvan 1999). However, 9 years 

after diameter-limit cutting, our data suggest that partial 

overstory shade is more favorable to red maple height 

growth than to the growth of black cherry and yellowpoplar. Red/black oaks accounted for only 1 percent 

of the dominant/codominant stems and generally were 

overtopped by the other species. Of course factors such 

as intensity of deer browsing, annual seed production, 

site quality, and climate contribute to regeneration 

composition and development. For example, selective 

browsing by white-tailed deer rather than diameter-limit 

cutting was primarily responsible for the preponderance 
37

of black cherry on the West Virginia University Forest, 

even in the uncut stands. However, these variables were 

not measured in all of the studies discussed and are not 

reported here.

Acknowledgments

The studies conducted on the West Virginia University 

Forest were supported by the West Virginia University 

Division of Forestry with funding under the McIntireStennis Forestry Research Act. Data for the 2003 study 

were collected and analyzed as part of a master’s thesis 

project of Travis Deluca at West Virginia University. I 

thank Shawn Grushecky, Brian Tift, and Aaron Graves 

for assistance with data collection and analyses, as well as 

the many field technicians who have participated in the 

studies since 1993.

Literature Cited

Brashears, M.B.; Fajvan, M.A.; Schuler, T.S. 2004. 

An assessment of canopy stratification and tree 

species diversity following clearcutting in central 

Appalachian hardwoods. Forest Science. 50(1): 54-

64.

Fajvan, M.A.; Grushecky, S.T.; Hassler, C.C. 1998. The 

effects of harvesting practices on West Virginia’s 

wood supply. Journal of Forestry. 96(5): 33-39.

Fajvan, M.A.; Knipling, K.E.; Tift, B.D. 2002. Damage 

to Appalachian hardwoods from diameter-limit 

harvesting and shelterwood establishment cutting.

Northern Journal of Applied Forestry. 19(2): 80-87.

Littell, R.C.; Milliken, G.A.; Stroup, W.W.; Wolfinger, 

R.D. 1996. SAS system for mixed models, Cary, 

NC: SAS Institute.

Marquis, D.A.; Ernst, R.L. 1991. The effects of stand 

structure after thinning on the growth of an 

Allegheny hardwood stand. Forest Science. 37(4): 

1182-1200.

Marquis, D.A.; Ernst, R.L.; Stout, S.L. 1992. 

Prescribing silvicultural treatments for hardwood 

stands of the Alleghenies (revised). Gen. Tech. Rep. 

NE-96. Radnor, PA: U.S. Department of Agriculture, 

Forest Service, Northeastern Forest Experiment 

Station.

Miller, G.W.; Kochenderfer, J.N. 1998. Maintaining 

species diversity in the central Appalachians.

Journal of Forestry. 96(7): 28-33.

Nyland, R.D. ed. 1987. Managing northern 

hardwoods: proceedings of a silvicultural 

symposium; 1986 June 23-25; Fac. of For. Misc. Pub. 

13. (ESF 87-002); SAF Publ. 87-030. Syracuse, NY: 

State University of New York.

Oliver, C.D.; Larson, B.C. 1996. Forest stand 

dynamics. New York: JohnWiley and Sons.

Pell, J.A. 1998. Variables characterizing timber 

resource sustainability of recently harvested 

tracts across Pennsylvania. University Park, PA: 

Pennsylvania State University, School of Forest 

Resources. M.S. thesis.

Roach, B.A.; Gingrich, S.F. 1968. Even-aged silviculture 

for upland central hardwoods. Agric. Handb. 355. 

Washington, DC: U.S. Department of Agriculture.

Schuler, T.M. 2004. Fifty years of partial harvesting 

in a mixed mesophytic forest: composition and 

productivity. Canadian Journal of Forest Research. 

34: 985-987.

Smith, D.W. 1994. The Southern Appalachian 

hardwood region. In: Barrett, J.W. ed. Regional 

silviculture of the United States. New York: John 

Wiley and Sons: 173-225.

Smith, H.C.; Eye, M.C., eds. 1986. Guidelines for 

managing immature Appalachian hardwood 

stands: Workshop proceedings; 1986 May 28-30; 

Morgantown, WV. SAF Publ. 86-020., Morgantown, 

WV: West Virginia University Books.

Tift, B.D.; Fajvan, M.A. 1999. Red maple dynamics 

in Appalachian hardwood stands in West Virginia.

Canadian Journal of Forest Research. 29: 157-165.
38

Trimble, G.R. Jr., 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. Upper Darby, 

PA: U.S. Department of Agriculture, Forest Service, 

Northeastern Forest Experiment Station.

U.S. Department of Agriculture, Forest Service. 1986. 

Land and resource management plan. Milwaukee, 

WI: U.S. Department of Agriculture, Forest Service, 

Eastern Region. 
39

Economics, Markets, and Diameter-Limit Cutting

Kenny Fergusson

Huber Resources, Inc., Old Town, ME

small and low-grade trees. In some areas, managers can 

merchandise non-timber benefits as recreation leases 

or use fees, or they might offer conservation easements 

that help cover costs of taxes and other overhead 

expenditures. Those non-timber revenues might temper 

the balance between costs and returns from timber 

operations.

Since markets do not remain static through time, 

managers must regularly track price fluctuations, 

including the difference between species. An appropriate 

long-term strategy keeps the options open by not overcutting all the most valuable ones in any short period of 

time. To maximize the revenue potential, managers must 

also balance operating costs per unit of volume harvested 

against the price gain from growing trees to large sizes. 

The revenue curve shows that trees generally increase in 

value with size, but with net value eventually dropping 

due to rising operating costs. The peak of that curve 

suggests a size for financial maturity based on cash flow.

To contain operating costs, landowners must work 

with contractors to find a harvesting system fitted 

to the site conditions, the total harvestable volume, 

and the size and species of trees planned for removal. 

Working with contractors to communicate clear 

outcomes for each operation can save on marking and 

layout costs. Regular performance reviews and frequent 

communication with the harvesting contractor insure 

compliance at the harvesting site. Transportation costs 

may importantly affect stumpage value and revenues. 

Having a good network of logging roads or good access 

to well-maintained public roads also helps to reduce 

the operating costs. Managers must also take account of 

timber quality and harvested volume, using the higher 

value timber as an incentive for operating under the 

more challenging conditions. Further, offering fairly 

consistent harvestable volumes through all seasons 

provides continuity for the harvesting contractor and 

insures year-round operations on our lands.

A successful financial outcome from forest management 

depends upon finding an approach that is relevant to the 

situation and pays an adequate return to the landowner. 

That means assessing the stand and forest conditions 

on a property, the requirements and constraints of the 

ownership, the markets for products from the land, and 

the social framework that tempers the management 

options. Managers must also consider the operational 

costs of a program, the opportunities for generating 

revenues, and how these balance in the short and long 

run with respect to the management objectives. Stand 

treatments must sustain a desirable set of conditions 

on the ground, and insure a continuing flow of values 

consistent with the management objectives. 

Operational conditions often make classic silvicultural 

difficult or impractical. Instead, foresters must commonly 

adapt to several realities that constrain practical 

management. This includes the potential of a site, the 

species mix and the relative value of each one, the ages 

and sizes of trees in a stand, the vigor and quality of 

the growing stock, and the location and accessibility. In 

addition, the size of an ownership and its component 

stands affect the extent of yearly silvicultural operations 

that forestry can sustain, and the potential to annually 

generate revenues and other values that repay costs of the 

operations and provide a profit to the landowner. 

Landowners commonly set a limit on the risks they 

accept for investments in ownership, management, and 

holding growing stock on the land. So potential dangers 

like losses to blowdown, ice storms, outbreaks of harmful 

insects, and fire all influence when owners want to 

harvest trees from their lands, and how much residual 

value they willingly leave in a stand. Further, they may 

have expectations for realizing regular returns on their 

investments, both in the amount of revenues required 

annually and the consistency of yields through time.

Markets may ultimately control the options available, 

and particularly affect treatments that require cutting of 
40

The diameter often proves the most determinant factor of 

sawlog quality. Large-diameter logs yield greater amounts 

of high quality lumber and allow more options in milling 

and later processing. Appropriate bucking and sorting 

are also critical in optimizing value recovery from those 

pieces. Huber Resources controls this by transporting 

tree-length logs to a concentration yard where we buck 

the trees into shorter logs and separate them by product 

class. We also lay out the sawlogs in rows and periodically 

invite buyers to submit bids on individual ones. That 

has improved revenues. Other landowners might realize 

similar gains by working with harvesting contractors who 

sort logs by product to increase their own revenues. That 

should improve the stumpage prices they offer. 

Besides keeping track of cash flow, managers can use a 

variety of return-on-investment analyses to compare the 

long-term potential of different management options. 

They should account for changes in available volume 

and the component quality, the demands of markets and 

effects on the price of different species and roundwood 

products, changes in harvesting technology and the 

resultant costs, and the rate-of-return requirements of a 

landowner. How these factors come together importantly 

tempers the outcome, with the results depending both on 

the cutting strategy and the ownership framework.

Each owner has a unique set of financial requirements 

and reasons for owning a forest. That challenges foresters 

to clearly understand the objectives and find creative 

ways to adjust to the situation as it changes through 

time. Having trees of the larger diameters and good 

bole quality enhances the revenue potential. Yet cutting 

strategies that repeatedly remove only the large trees 

and leave the small ones have not historically provided 

consistent amounts of volume over the long run, and 

that reduces the chances of insuring a steady stream of 

revenues into the future. Even so, silviculture research 

has not effectively addressed the conflict between 

demands for short- vs. long-term profitability, nor offered 

solutions for practical management. That challenges 

foresters to find appropriate strategies for providing 

sustainable returns on the investment of ownership and 

management.
41

Genetic Effects of Diameter-Limit Cutting

Gary Hawley1, and Donald DeHayes1, Paul Schaberg2 and John Brissettee3

1

University of Vermont, Burlington

2

USDA Forest Service, Northeastern Research Station, Burlington, VT

3

USDA Forest Service, Northeastern Research Station, Durham, NH

trees removed) was there a significant reduction in 

heterozygosity.

In another study we assessed the genetics of a 300-tree 

white pine population, mapped the tree location and 

measured several tree age and growth characteristics, 

resulting a genetically-mapped forest. The stand had 

three age classes, with the oldest comprised mainly of 

wolf trees. Heterozygosity increased with age, except for 

the old wolf trees. Data also show a tendency for trees of 

poorer crown positions to have more rare alleles. In this 

study, a simulated harvest indicated that cutting the old 

trees (≥29 inches dbh) reduced the genetic diversity in 

the stand. Cutting mostly overtopped trees in this case 

study decreased the number of rare alleles.

We also evaluated the influence of long-term silvicultural 

selection on the genetic structure of an eastern hemlock 

forest at the Penobscot Experimental Forest in Maine. 

Plots in this forest received one of the following three 

treatments: 1) selection cuts in which small and poorformed trees were preferentially removed in 1957 and 

1977, 2) diameter-limit cuts in which trees 24 cm in 

diameter and larger were removed in 1952, 1973, and 

1994, or 3) no harvesting (an unmanaged control). 

Because of an association between the occurrence of 

rare alleles and tree phenotypes, phenotypically based 

tree removals were associated with a shift in allelic 

frequency. Where smaller trees with inferior phenotypes 

were preferentially removed (selection cut), the number 

of rare alleles was lower and estimates of future genetic 

potential were lower relative to the control. Because 

of the theoretical long-term evolutionary benefit of 

unique gene forms, the loss of rare alleles could diminish 

the potential of populations to adapt to and survive 

ongoing environmental change. In contrast, trees in the 

diameter-limit cuts had fewer rare alleles, more lowfrequency alleles, more lost alleles and interestingly were 

higher in heterozygosity. It appears that the increase in 

The long-term health and productivity of forests is 

influenced by genetic diversity that enhances resiliency in 

response to environmental change. Loss of specific genes 

and a reduction of overall genetic diversity could affect 

productivity, ecosystem stability, long-term survival, and 

evolution. Harvesting trees removes genes from a forest. 

The effect of this removal depends on the: 1. heritability 

of traits, especially growth; 2. inherent variability of a 

site; 3. age structure of a stand; 4. intensity and timing of 

the manipulations; 5. amount of advance regeneration; 

6. size and degree of isolation of the stand; 7. original 

level of genetic diversity; and 8. number and genetic 

make-up of residual trees. It is important to consider 

the short- and long-term impacts on the quality and 

sustainability of the residual stand following harvesting.

The genetic diversity of the residual stand following 

harvest can be changed in several ways. Through 

selection of certain phenotypes (outward appearance 

of individual) there could be a loss of or change in 

genetic diversity if there is a strong phenotype-genotype 

relationship or growth-genetic diversity relationship. 

Also, the genetic diversity of a stand could be 

compromised if there is a large reduction in population 

size, which might result in increased inbreeding or a 

poorly adapted residual stand. 

One way that we have assessed the genetic implications 

of diameter-limit cutting was by simulating the effect 

of different cutting strategies on red spruce populations 

of known genetic diversity. Selecting 25%, 50% and 

75% of trees to remove at random resulted in the loss 

of only one allele (one of multiple forms of a gene), and 

no significant change in heterozygosity (a measure of 

the proportion of the genes that are genetically variable). 

Selecting the fastest growing trees to be removed (based 

on basal area increment) led to a loss of 2, 4 and 15 

alleles, respectively, for the three cutting intensities. 

Only at the highest removal intensity (75% of fastest 
42

heterozygosity of trees in the diameter-limit cut was due 

to an increase in frequency of alleles that were rare in the 

control stand, thus increasing low-frequency alleles and 

increasing heterozygosity. However, productivity was low 

in this stand where the frequency of characteristically rare 

alleles was artificially amplified.

Differences between the three management strategies 

are evident in the effects on rare alleles. Rare alleles 

are generally thought to have deleterious effects on the 

growth and overall fitness of a tree. So, cutting smaller 

trees may remove some of these undesirable alleles 

from a population, and selection system cutting in an 

uneven-aged stand may have positive short-term effects 

on growth. This will presumably improve the short-term 

fitness of the stand as well. Yet the rare alleles reduced by 

selection system cutting and amplified by the diameterlimit cut may be vital to long-term adaptation and 

evolution of future generations. Findings from other 

researchers have found similar increases in rare alleles 

associated with poor quality, slow growing phenotypes.

Findings in our work that are supported by work of other 

researchers for a variety of conifer species have shown 

that limited removal of the largest or fastest-growing 

trees does not appear to significantly alter the population 

genetics. Yet repeated heavy removal of larger diameter 

trees may affect the residual stand. Findings suggest that 

the smallest and slowest growing trees in a population 

may contain high frequencies of alleles that are rare in the 

whole population. These individuals should not be left as 

the only residual trees. It appears that managers should 

leave trees of a range of sizes to insure that regenerating 

offspring have the maximum number of alleles. 

Maintaining this genetic diversity may be critical to the 

long-term survival and adaptability of a species.
43

Ethics Considerations with Diameter-Limit Cutting

Victor L. Ford

MeadWestvaco and Chair, Ethics Committee, Society of American Foresters

high grading did not result. I suspect that hardwood 

stands may respond similarly, but limiting diameter size 

is unknown. Diameter limit cutting in the strictest sense 

may not necessarily be high grading. The Dictionary 

of Forestry (Helms 1998) defines high grading as: the 

removal of the most commercial valuable trees (high-grade 

trees), often leaving a residual stand composed of trees of 

poor condition or species composition ...high grading may 

have both genetic implications ...and long term economic 

or stand health implications. Is high grading bad? The 

answer is yes in light of the long-term implications of 

the practice. It is not sustainable; the property owner’s 

“forest factory” is compromised so that all products of the 

forest may be affected. The “forest factory” concept is that 

the forest is a capital investment that produces tangible 

and intangible goods and services. The quandary is that 

one of the goods produced by the factory is the factory 

itself. By strict definition, high grading is bad because it 

decreases the present and future value of both the factory 

and products derived from that factory. If diameter limit 

cutting equates to high grading, then that practice is bad. 

Defining high grading in the field may be more difficult. 

A couple of questions come to mind. Does removal of 

shelterwood/seed tree overstory constitute diameter limit 

cutting or high grading? Does leaving wildlife trees be 

defined as high grading? The clear difference in high 

grading and using diameter limit cutting as a tool is the 

desired outcome. If the objectives are set, then the result 

of a practice is clearly evident. However, rationalizations 

for bad practices are all too often used instead of using 

forethought to a desired outcome. Very rarely do wellwritten management plans result in high grading.

Definition of Ethics and Codes of Ethics

Everybody knows what ethics are but they are difficult 

to describe. Lammi (1968) stated that ethics is the 

relationship of conduct with the goals of a particular 

profession or society as a whole. If ethical, this conduct 

contributes to the goals of the profession and society. 

Unethical practice hinders the achievement of the goals. 

Chapman (1947) distinguished religion from ethics by 

Abstract

High grading is a poor management practice by 

definition. It has serious long-term implications to stand 

structure and function. The use of this management 

technique creates some ethical dilemmas. By examining 

the codes of ethics for the Forest Stewards Guild, 

Association of Consulting Foresters, and Society of 

American Foresters, only the Society of American 

Foresters has a code that attempts to balance landowner’s 

rights and an environmental ethic. These seemingly 

two opposed views can create an ethics problem, but 

the forester must observe due diligence to keep from 

an ethics violation. Conversely, ethics violation charges 

are very difficult to prove in the case of diameter-limit 

cutting.

Introduction

The views of this paper are my own and may not 

represent any organization or affiliation that I have. This 

statement must be made to insure that the words and 

ideas do not have more weight or importance than my 

opinion. As someone who is interested in ethics and its 

practical application, this subject provides a fascinating 

case study. In fact, others actually have already rendered 

opinions on this topic (Lockhart and Nyland 2004). 

I propose to look at this problem in the light of three 

Codes of Ethics. The purpose of this paper is to provide 

the reader with a practical approach to determine when 

diameter-limit cutting may be a violation of ethics, 

how to be protected if placed in a dilemma, and what 

information is needed to bring charges against an 

individual who may have violated a code of ethics.

Diameter-Limit Cutting and High 

Grading

This conference has already discussed the implications 

of high grading and diameter limit cutting in eastern 

hardwoods. However, Reynolds (1980) found in the 

1950s that in loblolly and shortleaf pine that if the 

diameter limit was set high enough (>18 inches) and 

the poor material was removed from the smaller classes 
44

stating that religious tenets relate to human life as a whole 

while ethics relate to professional conduct. Lammi (1968) 

separated ethics from morals and morality on the basis 

of whether the rules and practices relate to society as a 

whole or relates to the activities of a particular group or 

profession. A profession has specific codes of behavior that 

members of that profession must conform in order to be 

allowed to practice. A stated code of ethics and adherence 

to that code is the mark of a true profession. One of the 

main purposes of professional societies is to codify these 

rules of ethics that govern the behavior of its members.

There are three main organizations of which professional 

foresters may be members that have a code of ethics 

and violations may occur: Society of American Foresters 

(SAF), Association of Consulting Foresters (ACF), and 

Forest Stewards Guild (FSG). Each has a list of their 

code of ethics on their respective website. The ethics of 

workmanship, conflicts of interest, employee/employer 

relations, public interactions and discourse, credit, and 

confidentiality all are almost identical for SAF and ACF. 

The Code of Ethics of the ACF is more client-centered 

and does not have a land ethic. The ACF code is very 

good at outlining business behavior and interactions. 

The FSG is eco-centric and has a very strong statement 

about land stewardship. There are no statements 

on professional or business interactions beyond the 

statements on forest value.

One of the purposes of a code of ethics is to inspire 

members to higher standard of behavior. This is certainly 

evident in the preamble of the SAF Code of Ethics. The 

preamble sets the tone for the Principles and Pledges. 

The theme is the balancing of long-term values of the 

forest, the environmental ethic, and the property rights 

of the landowner. It specifically states that landowners 

have responsibility to the long-term value of forestland. 

This dichotomy was spelled out by Lammi (1968) 

when he stated that ethics has a goal of freedom and 

responsibility. He stated that Chapman (1924) had 

argued the same point in his discourse that a forester’s 

concept of conservation rejected the responsibilities 

of the extremists who advocate low level of resource 

use (preservationists) or advocate immediate monetary 

rewards (despoilers). The ACF code and preamble is an 

excellent standard for business and professional conduct. 

The first code states: ACF Consulting Foresters will 

utilize their knowledge and skill for the benefit of society. If 

societal benefits include values from the forest, the first 

statement of this code could be interpreted as a land 

ethic or at least a sustainable value ethic. The principles 

of FSG are explicitly forest centered and nature oriented. 

If landowner objectives conflict with these principles, the 

forester should disassociate.

In the light of diameter limit cutting and high grading, 

where does each of these organizations stand? Obviously, 

anything that would diminish the values of the forest 

would be contrary to the principles of the FSG and 

the forester should not continue. For the ACF, if the 

landowner’s rights are paramount and the forester must 

follow the lead of the employer. For the purposes of this 

discussion, these organizations have different but “cut 

and dry” view of this topic. The Code of Ethics of the 

Society of American Foresters creates an ethical dilemma 

because it has both a landowner’s rights pledge and a 

land ethic. The problem is balancing the two principles 

that seem to be opposed.

SAF Code of Ethics and High Grading

Is high grading contrary to the SAF Code of Ethics? 

Principles 1 and 2 of the code deal with high grading 

issue. They are as follows:

1. Foresters have a responsibility to manage land 

for both current and future generations. We 

pledge to practice and advocate management 

that will maintain the long-term capacity of the 

land to provide the variety of materials, uses, 

and values desired by landowners and society. 

2. Society must respect forest landowners’ rights 

and correspondingly, landowners have a land 

stewardship responsibility to society. We pledge 

to practice and advocate forest management 

in accordance with landowner objectives and 

professional standards, and to advise landowners 

of the consequences of deviating from such 

standards. 

As foresters, we have an obligation to practice and 

advocate methods that result in long-term worth and 
45

productivity of the forests. We are ethically bound to 

place this at the forefront of our practices, but there is 

another side of the coin. The forest landowner has rights 

to the land they own especially to extract value from 

the property. In fact, continuing to produce acceptable 

rates of return from forestry investments will keep land 

in forests instead of alternative uses. The art of forestry 

is melding the landowner objectives and values with the 

current conditions of the forest stands that result in long 

term worth and productivity.

The conflict with the code can occur with two types of 

behaviors: the first is to knowingly high grade without 

explaining the consequences to the landowner or robbing 

the landowner of the value of his lands and the second is 

the landowner is only interested in immediate income. 

The first behavior not only violates Principles1 and 2 but 

also blatantly violates Principles 5 and 6 by not openly 

communicating with the client and by being dishonest. 

The second behavior is much more common and puts 

the forester in the middle of the dilemma. The landowner 

may have valid reasons for wanting the money now 

and he has the right to it. The forester has two options 

at this point; walk away or explain to the landowner 

the consequences of these actions. If the forester 

continues working for the landowner after explaining the 

consequences, he/she has fulfilled the obligation to the 

Code of Ethics, but the forester must continue to be an 

advocate of good silviculture throughout the process.

The procedures for ethics charges against members of 

the Society of American Foresters are found in the SAF 

By-Laws. This document can be found on the web site 

(www.safnet.org). Charges are instigated by a letter 

describing the violations with evidence to support the 

violations to the President of SAF. This letter must have 

at least two signatures and the charges can be made 

by anyone. One does not have to be a member to file 

charges. This letter starts a process of investigation that 

leads to acquittal or disciplinary action. The process 

is designed to protect the rights of the accused. The 

evidence needed to convict a member of unethical 

conduct for high grading would require considerable 

information. The intent of the landowner must be 

established, the forester’s behavior must be documented, 

and the outcome of the action must be proven. If one 

of these three points were to fail, the accused would be 

acquitted. 

Conversely, the foresters must protect themselves when 

placed in a compromised condition. Foresters must 

show due diligence. Copies of written correspondence 

on advice to the landowner and management plans 

are excellent pieces of evidence to demonstrate the 

forester’s intent. The demonstration of forethought and 

not rationalization will prove to be adequate to prevent 

conviction on an ethical charge.

One of the best pieces of advice on how to prevent ethics 

violations was stated by Patterson (1984) and modified 

by Irland (2001). The four simple questions that one 

must ask are:

What if everybody did it?

Would I want to read about it in the paper tomorrow?

What will it look like tomorrow?

Would I be comfortable explaining this to my 12-yearold?

By examining these questions, most ethical problems will 

be solved. In fact, we should be inspired to act in a more 

ethical manner than stated in the code. By doing this, we 

should be a better profession.

Literature Cited

Chapman, H.H. 1947. Does the “profession” of 

forestry need a code of ethics? Journal of Forestry. 

45: 61-64.

Chapman, H.H. 1924. The relation of the Society of 

American Foresters to the profession of Forestry.

Journal of Forestry. 22: 9-15.

Helms, J.A. 1998. The dictionary of forestry. Bethesda, 

MD: The Society of American Foresters. 210 p.

Irland, L.C. 2001. Ethical matters in TGT 

recertification. Presented at Maine Tree Growth Tax 

Law Recertification. Augusta, ME: [Publisher name 

unknown]. 

Lammi, J.O. 1968. Professional ethics in forestry.

Journal of Forestry. 66: 111-114.
46

Lockhart, B.R.; Nyland, R.D. 2004. Teaching 

professional codes of ethics to forestry and 

wildlife students: a case study using diameterlimit harvesting in a bottomland hardwood stand.

In: Proceedings of the fifth biennial conference on 

university education in natural resources: 75-91.

Patterson, A.E. 1984. Ethics in forestry: four self-help 

questions. In: Irland, L.C., ed. Ethics in Forestry 

(1994): 45-47.

Reynolds, R.R. 1980. The Crossett story – the 

beginning of forestry in southern Arkansas and 

Louisiana. New Orleans, LA: Gen. Tech. Rep. SO32. U.S. Department of Agriculture, Forest Service, 

Southern Forest Experiment Station. 40 p.
47

Rehabilitating Cutover Stands: Some Ideas to Ponder

Ralph D. Nyland

Faculty of Forest and Natural Resources Management, State University of New York 

College of Environmental Science and Forestry, Syracuse, NY.

over-stocked places dependent upon the initial placement 

of trees larger than the threshold cutting diameter. 

Within uneven-aged communities, diameter-limit 

cutting often removes all or most the age classes that 

had grown to merchantable sizes, leaving the saplings 

and poles. Some cuttings may also leave the cull or 

low-value sawtimber stems. Further, it does no tending 

of the residual trees to enhance stand quality and vigor. 

Commonly, a residual uneven-aged stand has no more 

than 60-70 ft2/ac of basal area, distributed in a patchy 

fashion. For even-aged stands, diameter-limit cutting 

has an even more devastating effect. It removes all the 

marketable trees, leaving trees of poor crown position, 

vigor, and quality. In addition, diameter-limit cutting in 

even-aged stands often leaves no more than 50-60 ft2/ac 

of basal area after even a single entry. The stands also 

have a patchy distribution of residuals.

Here’s The Issue

Landowners who have cutover stands usually 

want to rehabilitate them at no out-of-pocket 

cost. That always proves challenging. In fact, 

rehabilitation must start with the investment of 

assessing conditions that diameter-limit and other 

exploitative cuttings created. Then managers must 

identify ways to improve the situation, and finally 

select an alternative that minimizes additional cash 

outlays in the process. At best, they often settle on a 

least-cost approach, hoping it will return a stand to 

profitability in a reasonable time.

Yet landowners and their managers face a harsh 

reality. Having allowed or encouraged diameter-limit 

cutting, they already incurred a heavy cost in:

• production opportunities lost due to poor 

stocking after the heavy cutting

• reduced quality and vigor of the residual trees

• lessened revenues due to prior cutting of the 

most desirable species 

As a result, the rehabilitation commonly becomes a 

last resort for salvaging a hopeless situation, with little 

promise for turning an immediate profit. It often 

requires considerable investments under the worst of 

situations.

The Legacy

Diameter-limit cutting usually leaves stands with a 

patchy distribution of residual trees (Fig. 1), including 

crowded conditions in some areas and sizable openings 

or only widely spaced trees in others (Nyland 2002). 

In fact, assessments in New York indicated that the 

variability in basal area (reflected by the coefficient 

of variation) increased by at least 1.75 to 2.0 times 

due to diameter-limit cutting, but no more than 1.5 

times under silviculture. As a consequence, diameterlimit cutting results in incomplete and ineffective site 

utilization, with the dispersion of under-stocked and 

Thinned Unthinned

Diameter-limit cutting Diameter-limit cutting

Figure 1.—Common difference in canopy cover between even-aged 

stands after thinning and a diameter-limit cutting (adapted from 

Smith 1986).
48

To make conditions worse, when landowners allow 

diameter-limit cutting they often signal a lack of interest 

in controlling the logging process as well, and many 

times the operation leaves large numbers of damaged 

or destroyed trees. Injuries to the main stem reduce the 

value, and particularly from wounds to the butt log. 

Loss of broken off or bent over trees creates additional 

places of low residual density, further reducing the 

production potential of the stand. Logging on saturated 

soil also causes deep rutting, severing the roots of trailside 

trees, opening entry courts for fungi, and reducing the 

carbohydrate storage capacity of the affected trees (Shigo 

1985). These injuries often become manifest as crown 

dieback or decline during later periods of moisture stress. 

So managers must assess wounds to the bole and crown 

of residual trees, as well as damage to the root systems, 

when they search for the acceptable growing stock and 

make their judgment about continuing the management 

of a cutover stand.

Altogether then, landowners who want to rehabilitate 

cutover stands face some important challenges, 

particularly after two or more diameter-limit and other 

selective cuttings. These include (after Nyland 2003):

• few trees of good vigor and high quality remain, 

limiting the future potential for volume and 

value growth.

• the stand often has a patchy distribution of 

residual trees, resulting in incomplete site 

utilization and little control over understory 

development.

• limited usable volume remains, making a 

rehabilitation cutting commercially marginal or 

infeasible.

• a scarcity of large trees limits seed production, 

complicating attempts to establish a new cohort 

in stands lacking adequate advance regeneration.

• where past cutting proved dysgenic, the effect 

may carry over into new age classes that derive 

from the poor residual trees.

• interfering plants may dominate the understory, 

particularly in the more open areas, further 

challenging chances to regenerate new seedlings 

across the stand.

These aftermath conditions translate into production 

opportunities lost, and diminish the potential for 

profitable management in the years ahead. Under the 

worse of circumstances, they may require considerable 

investment to correct. Even in the least severe cases, a 

rehabilitation treatment will not necessarily restore a 

stand to its previous state. But it will set the stage for its 

gradual recovery to a more sustainable condition.

A Basic Strategy

Rehabilitation of cutover stands requires four basic 

measures:

1. even the spacing between residual trees by 

removing the poorest ones;

2. concentrate the growth potential onto trees of 

acceptable quality, or the potential to grow into 

ones of reasonable value;

3. regenerate a new cohort to fill the empty space; 

and

4. control interference to enhance regeneration 

success.

The need for each component differs between stands, 

forcing managers to carefully assess the situation before 

prescribing any rehabilitation treatment for a stand.

In making the appraisal, they must look at the 

distribution and abundance of acceptable growing 

stock trees, usually by watching for ones having these 

characteristics (after Smith 1995, Nyland 2003):

• at least a lower codominant within the original 

even-aged stand, or within a cohort of an 

uneven-aged community;

• at least 20-25% of the height with live branches;

• no epicormic branches on the lower bole;

• no holes or fruiting bodies on the main stem;

• less than 25% of the major branches dead or 

dying; and

• not leaning more than 10° off vertical, and no 

heavy forking.

In addition, preferable trees have live branches growing 

from all sides of the main stem (balanced crowns), and 

lack signs of structural weakness along the main stem or 

in the crown. The best ones also have few grading defects 

in the butt log, or a potential to heal over old branch 
49

scars with sufficient wood to yield high quality boards 

from the outer faces. In the final analysis, the alternatives 

depend upon the number and distribution of these 

acceptable trees, and the degree that they will increase in 

volume and value in the foreseeable future.

Excluding stands suited to management with fairly 

traditional silviculture, the rehabilitation will likely deal 

with two basic conditions:

1. stands with some good residual trees, but at a 

low density; and

2. stands of limited promise 

Rehabilitation for these will have some common 

elements, but the latter group will require more effort. 

Also, the financial requirements will differ appreciably.

Stands With Good Residuals

These stands lack sufficient acceptable trees for full site 

utilization, but have some worth growing to larger sizes 

as future sawtimber or pulpwood. The rehabilitation 

objectives include:

• retaining the best trees for future development; 

and

• creating a new age class beneath them.

Implementation would include reducing the residuals to 

extra wide spacing, concentrating the growth potential 

onto these few (the best) uniformly spaced trees, releasing 

any desirable advance regeneration, and establishing 

regeneration to fill the empty spaces.

Note that an even-aged northern hardwood stand at 

40% residual relative density should develop sufficiently 

for full site utilization within a 15-year period (Leak 

et al. 1969, Roach and Gingrich 1968), given uniform 

spacing among the residuals. But some cutover stands 

have insufficient acceptable growing stock to make that 

option appropriate. The patchy distribution of residuals 

also precludes reasonable site occupancy if left alone. 

Instead, conversion to a two-aged arrangement might 

prove suitable for the long run. In that case, if the longterm plan calls for each age class to occupy one-half of 

the growing space, and for keeping the older ones until 

they reach 16 to 18 in. dbh (with a crown radius of 

about 15 ft), the ideal post-rehabilitation stand should 

have residual trees at a 40-ft spacing (about 30 trees/

ac). That might leave so little basal area that in some 

localities landowners must obtain a permit for the heavy 

cutting. Then they could increase residual stocking above 

the jurisdictional threshold by leaving some marginal 

trees. They would return to remove these poor ones 

when stocking of the acceptable ones (including the new 

cohort) passes the critical jurisdictional level.

For cutover uneven-aged stands having no or only a few 

acceptable sawtimber trees, the cut might leave 50-60 

ft2/ac, with 2/3 of the basal area in poles (≥6 in. dbh) 

left at uniform spacing, and a disproportionate number 

of ones >8 in. dbh to promote their early movement 

into sawtimber. This strategy will brighten the ground 

and facilitate development of any advance regeneration. 

If stands still have a nominal component of acceptable 

sawtimber trees, then the treatment should make the 

spacing uniform among residuals and begin to balance 

the age classes by retaining trees of all sizes. An ideal 

stand with some acceptable sawtimber trees would have 

at least 55 ft2/ac of residual basal area, with:

• 20% in trees <6 in. dbh;

• 35% in trees 6-11 in. dbh; and

• 50% in trees of sawtimber size.

This low stocking would also brighten the understory 

considerably, and promote the rapid development of 

advance regeneration. Also, a stand at that stocking 

would support another entry in about 25 yrs, or 5 yrs 

sooner for each additional 10 ft2

 of residual growing 

stock in large poles and sawtimber (after Hansen and 

Nyland 1984).

Where a cutover even- or uneven-aged stand has 

appropriate advance seedlings, these cutting treatments 

will promote their growth. Further, seed from the 

residual sawtimber trees will help fortify the stocking of 

regeneration. Otherwise, landowners may need to add 

reinforcement planting to compensate for the shortage of 

regeneration, particularly in cases lacking a good in-stand 

seed source. In addition, they must control interfering 

understory vegetation where it occurs at a critical 

density (e.g., see Bohn and Nyland 2003). Yet if done 

by broadcast methods (e.g., mistblowing an appropriate 

herbicide) the site preparation will also eliminate the 
50

advance regeneration. So managers must have a plan to 

reestablish the new age class by some deliberate means.

Stands of Little Promise

Some cutover stands (particularly after two diameterlimit cuts) have too few acceptable trees, and the residuals 

often have such low vigor that they also produce little 

seed. In other cases, landowners must remove all or most 

of the ones present to make the rehabilitation cutting 

commercially feasible. In both cases, the treatment should 

remove the low-grade remnants, and create a replacement 

age class. Stands in this condition often also lack advance 

regeneration and have important amounts of interfering 

understory plants. So the rehabilitation must:

1. clean off the cull and low-grade trees;

2. leave any suitable ones that might serve as a seed 

source, or provide some future revenues;

3. do site preparation to reduce the understory 

interference; and

4. plant the voids with new trees.

Mechanized harvesting and access to a biomass or 

pulpwood market may make the cutting cost-neutral: 

providing sufficient revenues to pay costs of other aspects 

of the rehabilitation. In stands with only a low volume to 

harvest, landowners may need to trade the stumpage in 

return for getting the cutting done. That would reduce 

their investments to the cost of site preparation and any 

planting. Where stands lack advance regeneration or have 

only scattered seedlings, conversion to conifers may seem 

best, but at a real cost. So recovering sufficient volume 

for a commercial sale may prove essential in making the 

entire rehabilitaton cost-neutral. 

The Importance of Action

In severe cases where landowners will not commit to 

investing in these operations, they could wait until 

a stand grows sufficient volume to pay costs of the 

treatments. In some cases, landowners have opted to 

dispose of the property instead. Yet the latter of these 

alternatives just abdicates responsibility for the past 

and passes the problem to someone else. Hopefully, 

landowners will prefer to do something to improve the 

situation, so they can return their cutover stands to a 

more desirable condition.

Altogether, rehabilitation requires a commitment to 

reverse the past and initiate a program of sustainable 

forestry. In the long run, landowners will find better 

opportunities by practicing silviculture in the first place. 

Yet where they must embark on a rehabilitation program, 

they might choose among these options (Nyland 2003):

1. Look for trees with reasonably well-developed 

and balanced crowns1, good stem form, a 

marketable quality, and a potential to produce 

seed.

2. Keep sufficient numbers for future management, 

and cut the rest.

3. For uneven-aged stands, retain good trees of 

different sizes, interspersed throughout.

4. Remove just enough volume for a commercial 

harvesting operation, and to take out the 

unacceptable trees.

5. Leave uniform spacing, independent of the 

number kept for the future.

6. Deliberately establish a new age class, unless the 

overstory trees will fully occupy the site as they 

develop.

7. Reduce any interfering vegetation to insure 

regeneration success.

In essence, they should leave as many of the best trees 

as circumstances permit, keep them at uniform spacing, 

and regenerate a new age class to fill voids between and 

beneath the residuals. This means carefully evaluating 

the options, working out the costs with reference to the 

potential revenues, and guiding the decision-making to 

the best possible end result. 

Literature Cited

Bohn, K.K.; Nyland, R.D. 2003. Forecasting 

development of understory American beech after 

partial cutting in uneven-aged northern hardwood 

stands. Forest Ecology and Management. 180: 453-

461.

Leak, W.B.; Solomon, D.S.; Filip, S.M. 1969. A 

silvicultural guide for northern hardwoods in 

1

A balanced crown has live branches growing from all sides of 

the tree. Reserve trees should also have at least 20-25% of the 

main stem with living branches.
51

the Northeast. Res. Pap. NE-143. Upper Darby, 

PA: U.S. Department of Agriculture, Forest Service, 

Northeastern Forest Experiment Station.

Nyland, R.D. 2002. Silviculture: concepts and 

applications. 2nd ed. New York: McGraw-Hill Book 

Co.

Nyland, R.D. 2003. Rehabilitating stands after 

diameter-limit cutting. In: Beland, M., ed. 

Proceedings of the tolerant hardwoods management 

conference; 2003 8 May; Edmundston, NB: 

Universite de Moncton-Campus d’Edmundston. 

[CD rom].

Roach, B.A.; Gingrich, S.F. 1968. Even-aged silviculture 

for upland central hardwoods. Agric. Handb. 355. 

Washington, DC: U.S. Department of Agriculture.

Shigo, A.L. 1985. Wounded forests, starving trees.

Journal of Forestry. 83(11): 668-673.

Smith, D.M. 1986. The practice of silviculture. 8th ed. 

New York: Wiley.

Smith, D.W. 1995. The southern Appalachian 

hardwood region. In: Barrett, J.W., ed. Regional 

silviculture of the United States. New York: Wiley: 

173-225.
Kenefic, Laura S.; Nyland, Ralph D. 2006. Proceedings of the conference on 

diameter-limit cutting in northeastern forests. Gen. Tech. Rep. NE-342. 

Newtown Square, PA: U.S. Department of Agriculture, Forest Service, 

Northeastern Research Station. 51 p.

Contains nine papers presented at the conference on diameter-limit cutting in 

northeastern forests on May 23-24, 2005, at the University of Massachusetts at 

Amherst. 

Printed on Recycled Paper
Headquarters of the Northeastern Research Station is in Newtown Square, 

Pennsylvania. Field laboratories are maintained at:

Amherst, Massachusetts, in cooperation with the University of Massachusetts

Burlington, Vermont, in cooperation with the University of Vermont

Delaware, Ohio

Durham, New Hampshire, in cooperation with the University of New Hampshire

Hamden, Connecticut, in cooperation with Yale University

Morgantown, West Virginia, in cooperation with West Virginia University

Parsons, West Virginia

Princeton, West Virginia

Syracuse, New York, in cooperation with the State University of New York, 

College of Environmental Sciences and Forestry at Syracuse University

Warren, Pennsylvania

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