United States Department of Agriculture

Indiana Forests 

2013

Forest Service Northern 

Research Station

Resource Bulletin

NRS-107

Publication Date 

December 2016
Abstract

This report summarizes the third full annualized inventory of Indiana forests conducted from 2009 to 

2013 by the Forest Inventory and Analysis program of the Northern Research Station in cooperation 

with the Indiana Department of Natural Resources, Division of Forestry. Indiana has nearly 4.9 

million acres of forest land with an average of 454 trees per acre. Forest land is dominated by the 

white oak/red oak/hickory forest type, which occupies 72 percent of the total forest land area. Most 

stands are dominated by large trees. Seventy-eight percent of forest land consists of sawtimber, 15 

percent contains poletimber, and 7 percent contains saplings/seedlings. Growing-stock volume on 

timberland has been rising since the 1980s and currently totals 9.1 billion cubic feet. Annual growth 

outpaced removals by a ratio of 3.3:1. Additional information on forest attributes, changing land use 

patterns, timber products, and forest health is included in this report. Detailed information on forest 

inventory methods and data quality, a glossary of terms, tabular estimates for a variety of forest 

characteristics, and additional resources are available online at http://dx.doi.org/10.2737/NRSRB-107.

Acknowledgments

The authors would like to thank numerous individuals who contributed both to the inventory and 

analysis of Indiana’s forest resources. Primary field crew and QA staff for the 2009-2013 field 

inventory cycle included: Josh Anderson, Craig Blocker, Lance Dye, Jake Florine, Matt Goeke, Aaron 

Hawkins, Justin Herbaugh, Jacob Hougham, Pete Koehler, Greg Koontz, Kasey Krouse, Dominic 

Lewer, Derek Luchik, Sally Malone, Andy Mason, Will Smith, Jason Stephens, Glen Summers, 

Tom Thake, Mark Webb, and Greg Yapp. Pre-field production staff included: Daniel Kaisershot, 

Cassandra Olson, Rebekah Price, Lucretia Stewert, and Jeff Wazenegger. Data management 

personnel included: James Blehm, Mark Hatfield, and Jay Solomakos. Report reviewers included 

John R. Seifert, Philip T. Marshall, Jeff Settle, and Scott Haulton of Indiana’s Department of Natural 

Resources. 

Cover: Beautiful autumn view of Clark State Forest in Indiana from the fire tower. Photo by Indiana Department of 

Natural Resources, used with permission.

Manuscript received for publication October 2015.

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Indiana Forests, 2013

Dale D. Gormanson, Joey Gallion, Charles J. Barnett, Brett J. Butler, Susan J. Crocker, Cassandra 

M. Kurtz, Tonya W. Lister, William Luppold, William McWilliams, Patrick D. Miles, Randall S. Morin, 

Mark D. Nelson, Barbara M. O’Connell, Charles H. Perry, Rachel I. Riemann, Ronald J. Piva, 

James E. Smith, Paul A. Sowers, James A. Westfall, and Christopher W. Woodall

Contact Author: 

Dale D. Gormanson 

dgormanson@fs.fed.us 

651-649-5126

About the Authors

Dale D. Gormanson and Ronald J. Piva are 

foresters with the Forest Inventory and Analysis 

(FIA) program, Northern Research Station, 

St. Paul, MN.

Charles J. Barnett is a biological scientist with 

the FIA program, Northern Research Station, 

Newtown Square, PA.

Brett J. Butler is a research forester with the 

FIA program, Northern Research Station, 

Amherst, MA.

Susan J. Crocker, Patrick D. Miles, Mark 

D. Nelson, and Christopher W. Woodall are 

research foresters with the FIA program, 

Northern Research Station, St. Paul, MN.

Joey Gallion is a forest inventory program 

manager with the Indiana Department of Natural 

Resources, Brownstown, IN.

Cassandra M. Kurtz and Paul A. Sowers 

are natural resource specialists with the FIA 

program, Northern Research Station, 

St. Paul, MN.

Tonya W. Lister, William McWilliams, Randall S. 

Morin, and James A. Westfall are research 

foresters with the FIA program, Northern 

Research Station, Newtown Square, PA.

William Luppold is an economist with the 

FIA program, Northern Research Station, 

Princeton, WV.

Barbara M. O’Connell is a forester with the 

FIA program, Northern Research Station, 

Newtown Square, PA.

Charles H. Perry is a research soil scientist with 

the FIA program, Northern Research Station, 

St. Paul, MN.

Rachel I. Riemann is a research forester/

geographer with the FIA program, Northern 

Research Station, Troy, NY.

James E. Smith is a research plant physiologist 

with the FIA program, Northern Research 

Station, Durham, NH.
Foreword

Welcome to Indiana Forests 2013, the latest results of our statewide forest inventory. 

This inventory is an ongoing joint venture between the Indiana Department of Natural 

Resources Division of Forestry and the Forest Inventory and Analysis program of the 

U.S. Forest Service. Results from this seventh inventory show Indiana forests continue to 

grow more wood than is being harvested, providing an important and essential element 

to Indiana’s economy, the wood industry, and individual woodland owners. Indiana 

forests have expanded to nearly 4.9 million acres with an average volume of over 2,000 

cubic feet per acre. These productive forests provide homes and food for wildlife; clean 

our water and air; protect soil that would otherwise disappear due to erosion; and 

provide fine quality hardwood products to Hoosiers, Americans, and the world. 

Indiana is fortunate to have a productive and high quality stand of forest land, yet the 

industry is vulnerable to economic cycles. Eleven percent of all exported agricultural 

products are wood products, but that has not kept pace with other agriculture exports. 

Opportunities abound to further enhance the value of Indiana wood products to the 

economy through its export channels as well as by providing employment. Every 1,000 

acres of forest land directly supports nearly eight manufacturing jobs in the primary, 

secondary, and ancillary wood-using industry.

While Indiana forests continue to be resilient and are actually expanding, there are 

concerns. Regeneration of some shade intolerant species such as oaks and hickories 

could be better. Average tract size continues to decrease with indications these holdings 

may also be changing ownership. Ash tree mortality resulted in a loss of 11 million 

cubic feet of volume per year, mostly attributed to the emerald ash borer, a nonnative 

insect accidentally introduced in Michigan that has spread to other states. There are a 

growing number of invasive plant species outcompeting native vegetation for sunlight 

and nutrients. In addition, white-nose syndrome is deadly to many of our beneficial 

forest- and cave-dwelling bats. All of these issues need to be monitored, and future 

management decisions may need to be altered to address such concerns. 

I invite you to read and interpret the results of Indiana Forests 2013. Hopefully you 

enjoy perusing the information. As a result, perhaps you will become more interested in 

our State’s forests and then participate in the discussions about the future of forests and 

forestry in Indiana.

John Seifert, State Forester
Contents

Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Forest Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Forest Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Forest Economics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Future Forests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

Appendixes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152

Statistics, Methods, and Quality Assurance . . . . . . . . . . . . . . . . . . . . . . . . . . 

Online at http://dx.doi.org/10.2737/NRS-RB-107

Indiana Forests Summary Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Online at http://dx.doi.org/10.2737/NRS-RB-107

Additional Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Online at http://dx.doi.org/10.2737/NRS-RB-107
The one-mile loop trail at Tall Timbers Nature Preserve passes by a stand of old growth forest along Big Walnut Creek. 

Photo by Indiana Department of Natural Resources, used with permission. 
 | 1

Highlights

On the Plus Side

• Eighty-four percent of Indiana’s forest land is privately owned by corporations and 

family forest owners. The vast majority, an estimated 3.6 million acres (73 percent), 

are owned by family forest owners. An estimated 85,000 family forest ownerships 

across Indiana each own at least 10 acres of forest land.

• The statewide increase in timberland area between 1986 and 2013 may be attributed 

to farmland reversion; approximately 750,000 acres, nearly 20 percent, of privately 

owned forest land are enrolled in the Classified Forest and Wildlands Program 

(CFW). More than 13,000 landowners participate in the CFW program, and it 

appears conservation and stewardship measures are affecting the extent and quality 

of Indiana forests. 

• Over the past six decades, the area of Indiana timberland increased slightly from 

4 to 4.7 million acres. Over that same period, the volume of growing-stock timber 

nearly quadrupled from 2.6 to 9.5 billion cubic feet.

• Yellow-poplar continues to be the most voluminous species followed by sugar 

maple and white oak. Black cherry had the greatest percentage increase in 

volume—17 percent.

• The mortality rate in Indiana (1.1 percent) is similar to that in the neighboring 

states of Ohio (1.1 percent), Kentucky (1.0 percent), Illinois (1.6 percent), and 

Michigan (1.1 percent).

• During the recent recession, the number of employees working in the forest 

products industry hit its lowest level in 2010, while annual payroll (actual dollars) 

and the total value of shipments (actual dollars) bottomed out in 2009. After 

decreasing by 44 percent between 2004 and 2010, the number of employees 

working in the forest products industry increased by 13 percent between 2010 and 

2013.

Issues to Watch

• Indiana forests are being affected by urbanization and fragmentation. Only 21 to 45 

percent of the forest land in Indiana meets the definition of core forest statewide, 

and between 24 and 41 percent of the forest land is in unconnected fragments.
2 | 

• Future changes in Indiana’s forest land will depend on the pace of land development 

and, to a great extent, the economics of farming since idle farm land has been 

the source of much of the increase in forest land. Recently farm land prices have 

increased, suggesting that losses in farmland will likely slow or reverse. Increasing 

farmland values could also shift more development pressure to forest land.

• Invasive plant species were detected on more than 90 percent of the inventory plots. 

The data suggest that these plants are present throughout the State and have become 

widespread.

• Since 2008, mortality of live ash trees on forest land has increased by nearly 

two-thirds, averaging close to 1 million trees per year. By volume, this mortality 

represents an annual loss of 11 million cubic feet, an increase of more than 25 

percent from 2008. This rate of mortality and volume loss is expected to continue 

through the next 5-year inventory cycle (through 2018) and then decrease and 

return to normal mortality levels as emerald ash borer completes its mortality wave 

through Indiana, which is expected to occur between 2018 and 2020.

• The current trajectory away from dominance by oaks represents a long, slow change 

that has implications for biodiversity, wildlife, recreation, and the forest products 

industry.

• Stands continue to shift to the sawtimber (large diameter) size class. In 2013, 

approximately 80 percent of the stands are in age classes greater than 40 years 

old and 78 percent are in sawtimber-size stands. Indiana forests are maturing. 

Currently, nearly half (48 percent) of the stands are over 61 years of age.

• The fungus, Geosmithia morbida, a component of thousand cankers disease (TCD), 

has been detected in Indiana. The fungus is deadly to black walnut trees but has 

not yet been detected in any black walnut trees. In Indiana there are an estimated 

40.3 million walnut trees with a d.b.h. >1 inch. Approximately 17.7 million board 

feet of black walnut are harvested annually with a value of $21.4 million. If all forest 

walnut trees in Indiana died because of TCD, it would represent a $1.7 billion loss. 

Because walnut is a high value species, it is important for landowners to monitor 

black walnut stands for the presence of the fungus. 
 | 3

Background

Elk Creek trailhead of the Knobstone Trail in Jackson-Washington State Forest preserves the region's unique forested 

knobs. Photo by Indiana Department of Natural Resources, used with permission.

 | 3
4 | BACKGROUND

Forest Inventory Primer

Why inventory?

Inventories are the foundation for management planning (Schreuder et al. 1993). A 

viable business must have up-to-date inventories on all parts and related activities in 

order to make sound management decisions (Anderson et al. 1976). In the context 

of a national forest survey, a contemporary nation must have up-to-date forest 

inventories on all parts and related activities in order to frame forest policy and make 

sound forest management decisions that may include protection, utilization, and 

sustainability. Forest inventories have a long and illustrious history in the U.S. Forest 

Service. It is difficult to manage forest resources without a good inventory. If resource 

supplies run low or are feared to be low, or are affected by diseases, insects, drought, 

floods, or wind, monitoring of the forest resource becomes equally important 

(Schreuder et al. 2004).

The U.S. Forest Service, Forest Inventory and Analysis (FIA) program serves this 

capacity. FIA strategic, design-based, multi-resource inventories provide current 

information on the amount of and trends in forest resources. The measurement and 

remeasurement of permanent field plots provides information on forest composition; 

land-use changes including disturbance; forest growth, removals, and mortality; and 

other variables related to forest condition. 

What is a tree?

Trees are perennial woody plants with central stems and distinct crowns. In general, the 

Forest Inventory and Analysis (FIA) program defines a tree as a woody plant usually 

having one or more erect perennial stems, a stem diameter at breast height of at least 

3.0 inches, a more or less definitely formed crown of foliage, and a height of at least 15 

feet at maturity (see glossary of terms in the Statistics, Methods, and Quality Assurance 

section located online at http://dx.doi.org/10.2737/NRS-RB-107). A complete list of the 

tree species measured in this inventory can be found in Appendix 1. Throughout this 

report, the size of a tree is expressed in diameter at breast height (d.b.h.), in inches. This 

is the measured diameter, outside bark, at a point 4.5 feet above ground. 

What is a forest?

FIA defines forest land as land at least 10 percent stocked by trees of any size, 

including land that formerly had such tree cover and that will be naturally or 

artificially regenerated. Forest land includes transition zones, such as areas between 
 | 5

heavily forested and nonforested lands, that are at least 10 percent stocked with 

trees, and forest areas adjacent to urban and built-up lands. The minimum area for 

classification of forest land is 1 acre and 120 feet wide measured stem-to-stem from 

the outer-most edge. Unimproved roads, trails, streams, and clearings in forest areas 

are classified as forest if they are less than 120 feet wide. There are more specific area 

criteria for defining forest land near streams, rights-of-way, and shelterbelt strips (U.S. 

Forest Service 2012).

What is the difference between timberland, reserved forest 

land, and other forest land?

FIA defines three types of forest land: 

• Timberland is forest land that is producing or is capable of producing crops 

of industrial wood and is not withdrawn from timber utilization by statute or 

administrative regulation. These areas are capable of producing in excess of 20 cubic 

feet per acre (equivalent to about 1⁄4 cord) per year of industrial wood in natural 

stands. Inaccessible and inoperable areas are included. 

• Reserved forest land is all forest land that is withdrawn from timber utilization 

through statute without regard to productive status, e.g., some natural areas in state 

parks, national parks, and Federal wilderness areas. 

• Other forest land consists of forest land that is not capable of growing 20 cubic feet 

per acre per year and is not restricted from harvesting, e.g., some surface-mined 

areas with extremely degraded soil and some poorly drained areas where water 

inhibits tree growth. Sometimes such forest lands are referred to as being “less 

productive” or “unproductive” with respect to wood fiber production. 

Timberland accounts for 96.7 percent of the forest land in Indiana. About 3.3 percent 

of the forest land is deemed reserved.

How many trees are in Indiana?

Indiana forests dominate the landscape of southern Indiana and are composed 

primarily of oak/hickory forest types. Indiana’s forest land contains approximately 

2.2 billion live trees with a d.b.h. of at least 1 inch. The exact number of trees is 

not known because only a sample of trees was measured (35,807 trees), roughly a 

sampling rate of 1 out of every 61,771 trees. These trees were measured on a total of 

1,809 forest plots. 
6 | BACKGROUND

How do we estimate a tree's volume?

Forest inventories typically express volume in cubic feet, but the reader may be more 

familiar with cords (a stack of wood 8 feet long, 4 feet wide, and 4 feet high). A cord 

of wood contains approximately 79 cubic feet of solid wood and 49 cubic feet of bark 

and air.

Volume can be precisely determined by immersing a tree in a pool of water and 

measuring the amount of water displaced. Less precise, but much cheaper and easier 

to do with living trees, is a method adopted by the U.S. Forest Service’s Northern 

Research Station. In this method, several hundred trees were cut and detailed 

diameter measurements were taken along their lengths to accurately determine their 

volumes (Hahn 1984). Statistical tools were used to model these data by species 

group. Using these models, we can produce individual tree volume estimates based on 

species, diameter, and tree site index.

This method was also used to calculate sawtimber volume estimates. FIA commonly 

reports sawtimber board-foot volume using the International 1⁄4-inch rule. In Indiana, 

the Doyle log rule is commonly used. Although most of the sawtimber estimate 

findings in this report are presented using the International 1⁄4-inch rule, due to State 

and local interest, a number of sawtimber volume, growth, and removal estimate 

discussions are presented using the Doyle log rule. To convert from International 

1⁄4-inch rule to Doyle or Scribner board-foot scales see Smith (1991). An important 

point to remember is that log rules are just estimates of the final board-foot and cubic 

foot volume. Cassens (2001) presents background and practical usage of the three log 

rules.

How much does a tree weigh? 

The U.S. Forest Service’s Forest Products Laboratory developed estimates of specific 

gravity for a number of tree species (U.S. Forest Service 1999). These specific gravities 

are applied to estimates of tree volume to determine the biomass of merchantable 

trees (weight of the bole). Regression models are used to estimate the biomass of 

stumps (Raile 1982), limbs and bark (Hahn 1984), and belowground stump and 

coarse roots (Jenkins et al. 2004). Currently, FIA does not report the biomass of 

foliage. FIA reports biomass as either green or oven-dry weight. Green weight is the 

weight of a freshly cut tree. Oven-dry weight is the weight of a tree with no moisture 

content and is how biomass is measured in this report. On average, 1 ton of oven-dry 

biomass is equal to 1.9 tons (at 2,000 pounds/ton) of green biomass. 
 | 7

How can I analyze FIA data? 

In the past, FIA inventories were completed every 10 to 20 years. With these periodic 

inventories, it took decades to identify trends. With the new annual inventory, some 

trends will be easier to identify because a subset of observations (approximately 

20 percent) are made every year. It is still necessary to look over long time periods 

because many trends, like succession, can be difficult to discern in short time 

spans. Technologies, definitions, methods, location, ownership, precision, scale 

dependencies, and temporal trends are important factors to consider when analyzing 

FIA data. Estimates are derived from sample plots throughout a state. Larger areas 

of interest will contain more plots and thus produce more reliable estimates. For 

example, there may not be a sufficient number of plots within a county or single forest 

type with which to provide reliable estimates. It also is important to consider the 

degree to which a variable can be measured precisely. For instance, a stand variable 

like age is not as precise as forest type, and a tree variable like crown dieback is not as 

precise as diameter. Definitions and procedures have also changed over time. Prior 

to the 1999-2003 inventory cycle in Indiana (Woodall et al. 2005), for most attributes 

FIA reports and databases only included data collected on timberland plots. As a 

result, trend analyses that use data prior to 1999 are limited to timberland for many 

attributes. Since 1999, the new annual inventory design allows us to report volumes 

on all forest land. Comparisons of current growing-stock volume to estimates prior to 

1999 should be made with caution. Estimates of growth, removals, and mortality are 

based on remeasured plots across all forest land. In this report, most trend analyses 

focus on changes on forest land since 2008. 

Comparing data from different inventories 

The annual inventory measures a subset of observations (approximately 20 percent) 

every year. After 5 years of data collection, an analysis and report are created based on 

the full set, or “cycle” of plots. This creates a yearly moving window of 5-year cycles. 

The last year of each full cycle is used to identify the full set of plots. For example, 

the cycle of plots measured from 2009 through 2013 are collectively labeled the 

“2013 inventory” and were used to produce this 2013 report. Previous inventories 

of Indiana’s forest resources were completed in 1950 (Winters 1953), 1967 (Spencer 

1969), 1986 (Smith and Golitz 1988, Spencer et al. 1990), 1998 (Schmidt et al. 2000), 

2003 (Woodall et al. 2005), and 2008 (Woodall et al. 2011). 

To improve the consistency, efficiency, and reliability of the inventory, updates have 

been implemented over time. For the sake of consistency, a new, national plot design 

was implemented by all FIA units across the United States in 1999 (see the Statistics, 

Methods, and Quality Assurance section online). These major changes are reflected in 
8 | BACKGROUND

the Indiana annual inventory that started in 1999. Prior to this new plot design, fixed 

and variable-radius subplots were used in the 1986 and 1998 inventories. The new 

design uses fixed-radius subplots exclusively. Both designs have strong points but they 

often produce different classifications for individual plot characteristics. Unpublished 

FIA research comparing these plot designs showed no noticeable difference in 

volume and tree-count estimates. Fewer and less precise forest types were assigned 

in the periodic inventories, but methods for determining stocking, forest type, and 

stand-size estimates have been improved twice since the annual inventory started. 

All annual data were updated with the improvements to facilitate easier temporal 

analyses. For additional information, see Arner et al. (2003). 

Information published in this report and in related tables is based on the Forest 

Inventory and Analysis Database (FIADB), accessed from January-June 2015. Data 

were collected under field guides 4.0 to 6.02 and were compiled in National Information 

Management System (NIMS) version 6.0, installed on November 15, 2012. Due to 

occasional changes to NIMS and FIADB, trend analyses should be made using FIA’s 

online estimation tools, not by comparing published reports or tables. FIA estimates, 

tabular data, and maps may be generated at http://www.fia.fs.fed.us/tools-data/. See 

Bechtold and Patterson (2005) and O’Connell et al. (2014) for definitions and technical 

details. A glossary of terms is also available in the Statistics, Methods, and Quality 

Assurance section located online at http://dx.doi.org/10.2737/NRS-RB-107.

A word of caution on suitability and availability

The FIA definition of reserved forest land does not account for all the forest land that 

is unsuitable or unavailable for timber harvesting. FIA does not identify timberland 

withheld from timber utilization or timberland that is not suitable or accessible for 

timber harvesting. It would be difficult to identify and maintain an up-to-date list of 

all lands withheld and not suitable or accessible for timber harvesting due to changing 

laws, owner objectives, markets, and site conditions. 

Many factors make timberland unsuitable or unavailable for timber harvesting. For 

example, operability on some sites (e.g., wet or steep sites) is poor, and there are 

limitations related to wildlife. Threatened or endangered species habitat and oldgrowth areas may be subject to harvest restrictions. Some landlocked locations may 

be denied access, and the cost of entering some sites is prohibitive. There also are 

visually sensitive areas where aesthetics outweigh gains from harvests. FIA includes 

variables such as slope, physiographic class, and disturbance class that could help 

identify some lands with timber harvest constraints. It is also difficult to determine 

the availability of wood from private land. Many private land owners do not consider 

harvesting timber as an option for their timberland. The National Woodland Owner 
 | 9

Survey (NWOS) conducted by FIA quantifies private land owners’ management 

objectives and attitudes toward timber harvesting. These data are useful in assessing 

how much timber is actually available for harvesting. Thus, forest inventory data alone 

are inadequate for determining the area of forest land available for timber production. 

Additional factors, like those provided above, need to be considered when estimating 

the timber base, and these factors may change with time.

Introduction

This report summarizes Indiana’s third cycle of the annual forest inventory and covers 

the years 2009 through 2013. The completion of this cycle provided the Northern 

Research Station’s Forest Inventory and Analysis program (NRS-FIA or FIA) with the 

opportunity to remeasure plots from the second annual inventory cycle (2004-2008) 

(Woodall et al. 2011). In addition, trend estimates of average annual change (growth, 

mortality, and removals) were generated by remeasuring plots from the first cycle 

(1999-2003) (Woodall et al. 2005).

FIA groups contiguous counties that have similar forest cover, soil, and economic 

conditions into geographic units. Estimates of area and volume are more accurate 

at the unit level than at the individual county level because of the larger number of 

plots used to make the estimates. In addition, plots at the unit level are stratified into 

estimation units, meaning that the area for each unit is set to a known value, usually 

taken from the U.S. Census Bureau, whereas the area for counties is determined by 

the distribution of plots. Because of this, most analysis in this report will be at the 

state or unit level. County level data are available but should be used with caution. 

Indiana is divided into four FIA units. In the fertile corn belt (Northern Unit), lands 

are well-suited for agriculture. Terrain in this glaciated unit is mostly level to rolling 

with rich soils. The Knobs, Lower Wabash, and Upland Flats Units encompass 

Indiana’s hill country where Indiana’s topography generally becomes relatively rough 

and discourages farming in many of the areas. There is a close correlation between the 

amount of forest land and landscape relief. The relatively flat Northern Unit is sparsely 

forested. The three southern tier survey units cover about 40 percent of the land 

and water area but contain over 70 percent of the forest, with the Knobs survey unit 

containing about 40 percent of the forest (Fig. 1).
10 | BACKGROUND

Figure 1.—Forest cover (dark green) by FIA unit, Indiana, 2013. Forest cover was derived by linking plot data to MODIS 

satellite pixels (250 m) which utilizes gradient nearest neighbor techniques (Wilson et al. 2012).

Northern

Upland 

Flats

Knobs

Lower 

Wabash
 | 11

Log hauling team, Forest Township in Clinton County, Indiana, circa 1915. Photo by Sherman Wright, from Indiana 

Historical Society.

Historic Setting

Oaks (Quercus) and hickories (Carya) have been important species in Indiana and 

throughout the Central Hardwood region for the last several millennia (Fralish 2004, 

IN DNR 2008, Whitehead 1997). Following the retreat of the last glaciers from the 

Midwest, spruce (Picea) and fir (Abies) forests developed across prehistoric Indiana, 

which gave way to pine (Pinus), then hardwoods, approximately 9,500 years ago 

(Whitehead 1997). As the climate continued to warm and become drier, prairies 

expanded east through portions of present-day Indiana and Ohio, bringing with them 

an associated increase in wildfire (Fralish 2004). During this period it is likely oaks 

and hickories dominated the hardwood forests of the Midwest, eventually moving 

into uplands as precipitation levels rose after 5,000 years before present. The eventual 

invasion by mesophytic hardwoods (e.g., beech [Fagus], maple [Acer], ash [Fraxinus]) 

into bottoms and moist, rich slopes was associated with a period 5,000-6,000 years 

before present (Fralish 2004, IN DNR 2008, Parker and Ruffner 2004). It is likely that 

the advance of mesophytic hardwoods was slowed into uplands due to the use of fire 
12 | BACKGROUND

and land clearing by early Native American cultures (Fralish 2004). Jenkins (2013) 

provides a more detailed account of prehistoric and presettlement forest conditions in 

Indiana.

Most of the forests in Indiana are in some stage of recovery from human impacts. 

No official inventories of Indiana’s forested landscape exist prior to the mid-1900s. 

However, the forest primeval of Indiana as recorded in the original U.S. land surveys 

and an evaluation of previous interpretations of Indiana vegetation show that 

Indiana was more than 85 percent forest land (20 million acres) as recently as 200 

years ago (Carman 2013, Potzger et al. 1956). The type of cutting that occurred in 

the late 1800s had a profound effect on the composition of Indiana’s present forest. 

The high quality trees were cut off first: black walnut, yellow-poplar, black cherry, 

and white oak.1

 Later cuts removed every other marketable tree left on the land. 

The residual stands consisted of cull trees, small trees, and species not desirable 

for market use. The areas were often burned repeatedly to clear the brush (DenUyl 

1954). The land was converted to agricultural uses and was settled. Indiana was left 

with a highly disturbed and relatively young forest resource that regenerated under 

the influence of frequent fire, widespread grazing, farming, and farm abandonment. 

These disturbances favored the accumulation of oak and hickory reproduction more 

so than American beech, maple, yellow-poplar and other associates (Abrams 2003). 

By the early 1900s, the majority of Indiana forests had been cleared for agriculture 

or cut to provide raw materials for a growing nation. Considering the marketability 

and utilization standards of this period, there must have been many oak trees over 24 

inches in diameter (DenUyl 1954). The estimated total cut of hardwood sawtimber 

during the period from 1869 to 1903 was approximately 30 billion board feet, which 

equals an average yearly cut of about 800 million board feet. The records of amount of 

lumber cut are conservative because some operating sawmills did not report their cut. 

By that time, forests comprised approximately 1.5 million acres, or a mere shadow 

of about 7 percent of the original amount of forest land in the State. With reductions 

in large-scale clearcutting, wildfire, and woodland grazing in the mid-20th century, 

mesic species such as sugar maple, American beech, and yellow-poplar regenerated 

with notably greater success than oaks—even on sites that previously supported a 

vigorous oak overstory. Maple and beech were well adapted to the shaded understory 

of existing oak forests, and in the absence of periodic fires, the fast growing yellowpoplar was able to outcompete oaks and increase in dominance (Shifley and 

Woodall 2007). Carman (2013) provides a more detailed account of Indiana forest 

management history and practices.

1

 Scientific names for all trees species are listed in Appendix 1.
 | 13

What happened to the forests during the 20th century?

In 1950, Indiana forest land totaled 4.1 million acres (Winters 1953). By 2013, the 

amount of forest land increased by 800,000 acres to nearly 4.9 million acres (Fig. 2); 

however, the State total decreased from 1950 to 1967 (Schmidt et al. 2000), although 

the amount of timberland in southern Indiana increased. The loss, which was 

concentrated in the north-central part of the State, may be attributed to increased 

farming and the evolution from small family-run farms to larger agricultural 

operations. Between 1967 and 1986 timberland decreased in southern Indiana. The 

amount of forests being cleared for agricultural purposes leveled out or declined in 

the north; however, clearing forests for residential and commercial use continued, 

especially in southern Indiana. 

Figure 2.—Area of forest land and timberland by inventory year, 

Indiana. Error bars represent 1 standard error or a 68 percent 

confidence interval around the mean.

3.8 

4.2 

4.6 

5.0 

1948 1958 1968 1978 1988 1998 2008 2018 

Area (million acres) 

Year 

Timberland 

Forest land 

What does this mean

The forest composition and size structure in Indiana (and throughout the Central 

Hardwood region) are dynamic and are a product of past disturbances. Sixty years 

ago forests in Indiana were dominated by oaks (Winters 1953), but the original land 

surveys prior to widespread European emigration indicated a balanced mix of oak 

and beech-maple forest (Lindsey 1997, Potzger et al. 1956, Shifley and Woodall 2007). 

The statewide increase in timberland area between 1986 and 2013 may be attributed 

to farmland reversion; however, it also indicates that conservation and stewardship 

programs and measures are affecting the extent and quality of Indiana forests. This 

trend has continued for three inventory periods. For example, since its inception 

in 1985, more than 21,000 Indiana farmers have participated in the Conservation 

Reserve Program (CRP). Lands enrolled in the CRP cumulatively top more than 
14 | BACKGROUND

280,000 acres and include over 41,000 acres planted in trees and over 122,000 wildlife 

habitat acre plantings. CRP is a voluntary program that allows eligible landowners 

to receive annual rental payments and cost-share assistance to establish long-term, 

resource-conserving covers on eligible farmland throughout the duration of their 

10 to 15 year contracts. Under CRP, farmers plant grasses and trees in fields and 

along streams or rivers. The plantings prevent soil and nutrients from washing into 

waterways, reduce soil erosion that may otherwise contribute to poor air and water 

quality, and provide valuable habitat for wildlife. Indiana producers or landowners 

who are interested in more information regarding CRP should contact their local 

Farm Service Agency (FSA) County Office or visit FSA online at www.fsa.usda.gov. In 

addition, privately owned forest land enrolled in the Classified Forest and Wildlands 

Program (CFWP) approximates 750,000 acres, or nearly 20 percent of the privately 

owned forest land (Fig. 3). More than 13,000 landowners participate in the CFWP. 

It appears that forest land has rebounded and new forested habitat is being developed 

for wildlife. More streams and riversides are becoming forested in the north, helping 

to filter and clean the State’s water. Through time, resources for forest products 

in northern Indiana may increase. Concurrent with this recovery, Indiana forests 

have continued to provide the raw materials needed by Indiana’s forest products 

industry. Conversely, southern Indiana has the most continuous forests in the State. 

Wildlife habitats will be affected should these forests decline or be parceled into 

smaller sections. Smaller and separate pieces of forest land are less likely to support 

animals that require large, forested areas. Managing resources for forest products 

may also become more challenging. In addition, road construction could rise due to 

the increased demand and need to reach the more numerous, smaller, and separate 

forests.

Although the condition of Indiana forest land has progressively improved since 1967, 

there have been some setbacks and challenges. Starting with the chestnut blight 

(Cryphonectria parasitica) in the 1920s, the list of exotic insects and diseases found 

in Indiana continues to grow, with new additions becoming more frequent. By the 

mid-1970s, Dutch elm disease (Ophiostoma ulmi) had devastated elms in the State. 

More recent and recurring forest health problems include the emerald ash borer 

(Agrilus planipennis). In addition, the thousand cankers disease (Geosmithia morbida) 

that infects black walnut poses a real threat. These threats and other concerns are 

addressed in this report and make managing Indiana’s future forests a continuing 

challenge.
 | 15

Figure 3.—Privately owned forest lands enrolled (red) in the Classified Forest and Wildlands Program (CFWP), 

Indiana, 2013.

CFWP lands

Forest
16 | BACKGROUND
 | 17

Forest Features

Spring ephemerals emerge in the old growth forest at Calvert and Porter Nature Preserve. Photo by Indiana Department 

of Natural Resources, used with permission.

 | 17
18 | FOREST FEATURES

Forest Area

Background

The quantity, quality, structure, composition, age, and general health of our forest and 

timber lands are key measures for assessing forest resources and making informed 

decisions about their management and future. Trends in the forest land base serve as a 

barometer of forest sustainability, wetland and forest health, and land use stewardship 

practices. Gains and losses in forest area directly affect the benefits forests provide, 

including clean air and water (watershed protection), wildlife habitat, prevention of 

fertile soil erosion, materials for medicines, renewable energy development, wood 

products, and outdoor recreation opportunities like hiking, biking, camping, fishing, 

hunting, viewing wildlife, and enjoying nature.

FIA broadly classifies forest land into three components that describe the potential of 

the land to grow trees: reserved forest land, timberland, and other forest land. These 

categories help increase our understanding of the value and benefits of the forest 

resource and guide forest management and planning for future generations.

What we found

Indiana forests have increased in area by 800,000 acres since 1950 and now comprise 

nearly 4.9 million acres, with the percentage of land in forest cover increasing from north 

to south (Fig. 4). The State is divided into four survey units (Fig. 5), with forest land 

unevenly distributed among units: Northern (1.4 million acres), Lower Wabash (930,000 

acres), Upland Flats (676,000 acres), and Knobs (1.9 million acres). The Knobs and Lower 

Wabash Units showed timberland losses between 1986 and 2003 but rebounded by 2013 

(Fig. 6). The Upland Flats and Northern Units have experienced gains in forest land since 

1986, and these gains combined with the units that have increased since 2003, account for 

the recent increase in forest land for the State. 

Forest lands cover 21 percent of the land area in Indiana (Fig 7). Successive inventories 

have shown forest land area steadily increasing since 1986. The net increase of 131,229 

acres (2.8 percent) since 2008 is just barely large enough to be statistically different 

from the 2008 estimate, although data from other sources showing decreases in farm 

land acreage support this increase in forest land. In terms of gross change, plot data 

show both gains and losses in forest. Since 2008 approximately 95,000 acres of forest 

land have been converted to nonforest land uses, and 177,000 acres of nonforest 

land have reverted to forest. Since 1950, the amount of land in farms (including farm 

woodlots) has decreased by 4.9 million acres (Fig. 8). Although a large amount of farm 

land has been developed to meet the needs of a growing population, some has been left 

untended and has reverted to forest through natural succession. 
 | 19

Area of Forest Land 

(percent of county 

land area)

Nonforest

<10

10 to 20

21 to 40

41 to 60

61 to 83

Figure 4.—Distribution of forest land area by county, Indiana, 2013.

State Total

4,875,389 acres 

(21%)

Lower Wabash

929,826 acres 

(25%)

Knobs

1,886,243 acres 

(43%)

Northern

1,383,005 acres 

(10%)

Upland Flats

676,314 acres 

(41%)

Figure 5.—Acreage of forest land and percentage of land in forest by 

FIA unit, Indiana, 2013.
20 | FOREST FEATURES

0 

0.5 

1 

1.5 

2 

Lower 

Wabash 

Knobs Upland Flats Northern 

Forest Land Area (million acres) 

Inventory Unit 

1986 

1998 

2003 

2013 

Figure 6.—Area of timberland by inventory unit and year. Error bars represent 

1 standard error or a 68 percent confidence interval around the mean. 

Timberland 

(4,712,365 acres) 

21% 

Reserved 

Forest Land 

(158,719 acres) 

1% 

Nonforest land

(17,933,760 acres) 

78% 

Total forest land = 21% 

(4,875,389 acres) 

Other Forest Land 

(4,305 acres) 

<1% 

Figure 7.—Land area (acres) by major use, Indiana, 2013.

0 

5 

10 

15 

20 

25 

1950 1960 1970 1980 1990 2000 2010 

Area (million acres) 

Year 

14.7 

19.6 

Figure 8.—Area of farm and agricultural acreage (including 

farm woodlots), Indiana, 1950-2012 (NASS 2014).
 | 21

What this means

Increases in forest land have corresponded with decreases in farmland, but because of 

increased development in Indiana and a slowing in farm land losses, recent changes in 

total forest land have been small. These trends may indicate that the area of forest land 

in Indiana is nearing a peak. Future changes in Indiana forest land will depend on the 

pace of land development, and to a great extent on the economics of farming since idle 

farmland has been the source of much of the increase in forest land. Recent increases 

in farmland prices suggest losses in farmland will likely slow or reverse. Increasing 

farmland values could also shift more development pressure to forest land. Much of the 

forest land in Indiana is in close proximity to urban areas and derives value from its 

potential to be developed for residential housing and other nonforest purposes. A small 

percentage change in the area of nonforest land can significantly affect forest land area, 

especially in sparsely forested areas like Indiana’s Northern Unit.

Land-use Change

Background 

To better understand Indiana forest land dynamics, it is important to explore the 

underlying land-use changes occurring in the State. FIA characterizes land area using 

several land use categories which can be generalized to these classes: forest, rangeland, 

agriculture (including pasture and cropland), developed land, water, and other 

(including undeveloped beach, barren areas, and wetlands). The conversion of forest 

land to other uses is referred to as gross forest loss, and the conversion of nonforest land 

to forest is known as gross forest gain. The magnitude of the difference between gross 

loss and gain is defined as net forest change. By comparing the land uses on current 

inventory plots with the land uses recorded for the same plots during the previous 

inventory, forest land-use change dynamics can be characterized. Understanding landuse change dynamics is essential for monitoring the sustainability of Indiana’s forest 

resources and helps land managers make informed policy decisions.

What we found 

Indiana is dominated by agricultural land uses which cover 65 percent of the State’s area 

(Fig 9). Other nonforest areas in the State include developed land (including rights-ofway, 13 percent), water (1 percent), other land (1 percent), and rangeland (<1 percent). 

Based on remeasured plots alone, approximately 20 percent of Indiana was forested in 

2013. This nearly mirrors the actual 21 percent statewide estimate based on all plots 

which includes plots that were previously not forested but reverted to forest and were 
22 | FOREST FEATURES

measured for the first time during the 2013 inventory cycle. Most of the FIA plots 

in Indiana either remained forested or stayed in a nonforest use (20 percent and 79 

percent, respectively), and only the remaining 2 percent of plots experienced either a 

forest loss or gain from 2008 to 2013 (Fig. 10). 

According to the FIA remeasurement data, Indiana lost nearly 95,000 acres (2 

percent) of forest land from 2008 to 2013, which was more than offset by a gain of 

approximately 177,000 acres during the same time period (Fig. 11). Fifty-five percent 

of the forest gains come from agricultural uses including cropland (36 percent), 

pasture (11 percent), and other agriculture land (8 percent). The remaining fortyfive percent of newly added forest land was formerly classified as developed land (41 

percent), rights-of-way (8 percent), other (4 percent), and water (2 percent). More 

forest land was lost to developed and rights-of-way land uses (45 percent) than to the 

agricultural land use classes combined (31 percent). Some forest land was also diverted 

to other uses (16 percent) and water (10 percent) (Fig. 12).

FIA data can be used to characterize the forest land that has been lost and gained to 

see if it differs from the characteristics of forest land in all of Indiana. The forests of 

Indiana are dominated by stands in the large diameter size classes, with only 7 percent 

of forests in small diameter stands. The forest land that was gained, however, has a 

greater proportion of small diameter stands (39 percent) than in Indiana as a whole. 

An examination of change in forest area by county indicates that 41 of the 92 counties 

in Indiana have experienced gains in forest area of more than 10 percent since 2003 

(Fig. 13). A north-south gradient pattern is evident in the degree of forest cover 

change as would be expected given a similar gradient in population, travel corridors, 

topography, and agricultural activity. The distribution of remeasured plots across 

Indiana, highlighting plots on which 25 percent or more of the area has experienced a 

loss or gain in forest land (Fig. 14), also reflects the concentration of forest change in 

the northern and southern thirds of the State.

Water 

1% 

Ag land 

2% 

Pasture 

4% 

Cropland 

59% 

Developed 

11% 

Right-of-way 

2% 

Other 

1% 

Forest 

20% 

Figure 9.—Land use composition of remeasured plots, 

Indiana, 2013.
 | 23

Forest in 2008 

and 2013 

20% 

1% 

Forest to 

nonforest 

<1% 

Nonforest to forest 

Nonforest in 

2008 and 2013 

79% 

Figure 10.—Land use change, Indiana, 2008 to 2013.

0 50 100 150 200 

Forest loss 

Forest gain 

Area (thousand acres) 

Water Other Developed Agriculture 

Figure 11.—Gross percent forest loss and forest gain by land use 

category, Indiana, 2008 to 2013. Error bars represent 1 standard 

error or a 68 percent confidence interval around the mean.

Water 

2% Ag land 

8% 

Pasture 

11% 

Cropland 

36% 

Developed 

31% 

Right-of-way 

8% 

Other 

4% 

Forest Gain 

Water 

10% 

Ag land 

13% 

Pasture 

5% 

Cropland 

23% 

Developed 

29% 

Right-of-way 

16% 

Other 

4% 

Forest Loss 

Figure 12.—Forest gain by previous land use and forest loss by 

current land use, Indiana, 2008 to 2013.
24 | FOREST FEATURES

Figure 13.—Change in the area of forest land by county, Indiana, 

2003-2013.

Change in Forest 

Area 2003 to 2013

>10% loss

0 to 10% loss

0 to 10% gain

>10% gain

Figure 14.—Distribution of forest change inventory plots 

showing forest gains and losses of 25 percent or more, Indiana, 

2008 to 2013. Plot locations are approximate.

FIA Remeasured Plots

Forest gain

Forest loss

Remained nonforest

Remained forest
 | 25

What this means 

Overall, there was a small net gain in forest land in Indiana from 2008 to 2013 which 

suggests a continued conservation and valuation of the State’s forest resources. 

This trend of increasing forest land is consistent with what was reported in the last 

inventory cycle; however, the magnitude of the net gain was greater in the previous 

inventory. This difference in magnitude can be attributed primarily to a drop in the 

amount of nonforest land that reverted to forest; the amount of gross forest loss 

remained relatively stable between the two inventory cycles. Agriculture, particularly 

within the northern corn belt, is the dominant land use in Indiana, and gains and 

losses in pasture, cropland, and other agricultural land appear to drive much of the 

land-use change dynamics in the State. High net farm income, low interest rates, 

and high farmland demand with limited supply are the recent trends for Indiana 

farmlands. Forest losses to agricultural uses in Indiana may be a result of increased 

demand for agricultural-based biofuels. With increased interest in domestic fuel 

sources, there may be increased demand for suitable cropland. 

Gains in forest land may come from agricultural land reverting to forests, especially 

land in close proximity to streams. There has been a concerted effort in the State’s 

public and private sectors to prioritize the reforestation of these riparian areas. 

Agroforestry efforts promote the maintenance of tree cover in the form of windbreaks 

and forest buffers that help sustain a high agricultural output while conserving and 

protecting Indiana’s soil and water resources. These forested areas are also important 

to Indiana’s wildlife populations. Riparian forests often connect to form wildlife 

corridors which allow for greater species movement. 

Some of the gains and losses of forest land in Indiana may be from marginal forest 

land moving into and out of the forest land base. This movement between forest 

and nonforest classifications may be a result of land meeting or not meeting FIA’s 

definition of forest land due to small changes in understory disturbance, forest extent, 

or forest cover. These fluctuations likely contribute to the losses from and gains in 

developed land and rights-of-way. Permanent forest loss to development may also be 

occurring, especially near larger cities in the State, including Indianapolis where the 

population has increased by more than 3 percent in the last 4 years. For the State as a 

whole, however, the area of forest land lost to development is relatively small. Rather, 

the primary land source for new development in Indiana is agriculture. Of the gains 

in developed land, 92 percent come from converted agricultural land versus 5 percent 

from forest land.
26 | FOREST FEATURES

Forest Ownership

Background

How land is managed is primarily the owner’s decision. Therefore, to a large extent, 

the availability and quality of forest resources, including recreational opportunities, 

timber, and wildlife habitat, are determined by landowners. By understanding the 

priorities of forest land owners, leaders of the forest conservation community can 

better help to meet their needs, and in so doing, help conserve Indiana forests for 

future generations. The National Woodland Owner Survey (NWOS), conducted by 

the U.S. Forest Service Forest Inventory and Analysis program, studies private forest 

landowners’ attitudes, management objectives, and concerns. It focuses on the diverse 

and dynamic group of owners that is the least understood—families, individuals, 

and other unincorporated groups, collectively referred to as “family forest owners.” 

The NWOS data reported here are based on the responses from 232 family forest 

ownerships from Indiana that participated between 2011 and 2013.

What we found

Public owners control approximately 800,000 acres of Indiana forest land, or 

roughly16 percent of the total forest land in the State (Figs. 15 and 16). This includes 

the Federal government who manages an estimated 400,000 acres of forest land 

(8 percent), of which half is in the Hoosier National Forest. State forest, park, and 

wildlife agencies are stewards of another 400,000 or so acres (7.5 percent), and local 

government agencies control an estimated 50,000 acres (about 1 percent) of forest 

land in the State. The remaining 84 percent of the forest land of Indiana is privately 

owned by corporations and family forest owners. The vast majority of these private 

acres, an estimated 3.6 million acres (73 percent), are owned by family forest owners 

(Fig. 17). Corporations own an estimated 400,000 acres (8 percent) and other 

private owners, including conservation organizations, unincorporated clubs and 

partnerships, and Native American tribes, own an additional estimated 100,000 acres 

(2 percent). 
 | 27

National Forest 206,255 

4.2% 

National Park Service 11,125 

0.2% 

Fish and Wildlife Service 19,560 

0.4% 

Department of Defense 123,396 

2.5% 

Other federal 19,639 

0.4% 

State 365,841 

7.5% 

County and Municipal 48,613 

1.0% 

Private 4,080,962

83.7%

Figure 15.—Forest land ownership (acres) and percentage 

of forest land owned, Indiana, 2013.

Forest Land Ownership

Hoosier NF forest

Hoosier NF nonforest

Private forest

Private nonforest

Other public forest

Other public nonforest

Figure 16.—Distribution of forest land by ownership category, 

Indiana, 2013. 
28 | FOREST FEATURES

0 20 40 60 80 100 

Local 

State 

Federal 

Other private 

Corporate 

Family 

Percentage 

Ownership Category 

Figure 17.—Indiana forest land ownership, Indiana, 2013.

0 10 20 30 40 50 60 70 80 90 100 

10-19 

20-49 

50-99 

100-199 

200-499 

500-999 

1,000+ 

Percentage 

Size of Forest Holdings (acres) 

Acres 

Ownerships 

Figure 18.—Percentage of owners and area owned for family 

forest ownerships of 10+ acres, by size of forest holdings, 

Indiana, 2013. Error bars represent 1 standard error or a 68 

percent confidence interval around the mean.

According to the NWOS, an estimated 85,000 family forest ownerships across Indiana 

own at least 10 acres of forest land, for a total of 3.2 million acres. The average forest 

holding size of this group is 37 acres. Of these family forest ownerships, 79 percent 

own less than 50 acres of forest land, but 56 percent of the family forest land is in 

holdings of at least 50 acres (Fig. 18). The primary reasons for owning forest land are 

related to aesthetics, wildlife, nature protection, and family legacy (Fig. 19). The most 

common activities on their land are personal recreation, such as hunting and hiking, 

and cutting trees for personal use, such as firewood (Fig. 20). Most family forest 

ownerships have not participated in traditional forestry management and assistance 

programs in the past 5 years; the most common is having received management advice, 

but this is less than 25 percent of the ownerships (Fig. 21). The average age of family 

forest owners in Indiana is 62 years, and 39 percent of the family forest land is owned by 

people who are at least 65 years of age (Fig. 22).
 | 29

0 20 40 60 80 100 

Cabin 

Timber 

Firewood 

Hunting 

Recreation 

Family 

Farm 

Investment 

Water 

Privacy 

Home 

Legacy 

Nature 

Wildlife 

Beauty 

Percentage 

Reason for Owning 

Acres 

Ownerships Nontimber forest products 

Figure 19.—Reasons for owning forest land by percentage of 

owners and area owned, for family forest ownerships of 10+ 

acres, Indiana, 2013. Error bars represent 1 standard error or a 68 

percent confidence interval around the mean.

0 10 20 30 40 50 60 70 80 

Controlled burn 

Eliminated insects 

Roads 

Reduced fire hazard 

Grazing 

Wildlife habitat 

Cut trees-sale 

Trails 

Invasives 

Cut trees-personal 

Recreation 

Percentage 

Activities 

Nontimber forest products 

Acres 

Ownerships 

Figure 20.—Most common activities of family forest ownerships 

with 10+ acres, Indiana, 2013. Error bars represent 1 standard 

error or a 68 percent confidence interval around the mean.
30 | FOREST FEATURES

0 20 40 60 80 100 

Easement 

Certification 

Management plan 

Cost share 

Tax program 

Advice 

Percentage 

Management and Assistance Programs 

Acres 

Ownerships 

Figure 21.—Participation of family forest ownerships of 10+ acres 

in traditional forestry management and assistance programs in the 

past 5 years, Indiana, 2013. Error bars represent 1 standard error or 

a 68 percent confidence interval around the mean.

0 20 40 60 80 100 

<45 

45-54 

55-64 

65-74 

75+ 

Percentage 

Age (years) 

Acres 

Ownerships 

Figure 22.—Average age of family forest owners with 10+ acres, 

Indiana, 2013. Error bars represent 1 standard error or a 68 

percent confidence interval around the mean.

What this means

The fate of the forest lies primarily in the hands of those who own and control 

the land. It is therefore critical to understand forest owners and what policies and 

programs can help them conserve the forests for current and future generations. 

Family forest ownerships own their land primarily for amenity reasons, but many 

are actively doing things with their land. Timber production is not a priority in 

landowners’ minds, but they are not adverse to harvesting and other activities in 

their woods. More than 90 percent of them do not have a management plan nor have 
 | 31

they participated in most other traditional forest management planning or assistance 

programs. Natural resource professionals need to better communicate with family 

forest owners and help them better manage their woods. Programs such as Tools for 

Engaging Landowners Effectively (http://www.engaginglandowners.org) can help 

the conservation community develop and implement programs more effectively 

and efficiently. In addition, a viable private forest and wildland management 

option is the Indiana Classified Forest and Wildlands Program (http://www.in.gov/

dnr/forestry/4801.htm). The program encourages timber production, watershed 

protection, and wildlife habitat management on private lands in Indiana by providing 

a property tax reduction for owners who follow a professionally written management 

plan. The minimum requirement for program enrollment is 10 acres of forest, 

wetland, shrubland, and/or grassland.

In addition to the State CFWP there are federal programs such as the Forest 

Stewardship Program, Conservation Reserve Program, Environmental Quality 

Incentives Program, Forest Land Enhancement Program, Forest Legacy Program, 

Forestry Incentives Program, Wetlands Reserve Program, Wildlife Habitat Incentives 

Program, and State programs like the Indiana Lake and River Enhancement 

Program. There are also private industry assistance programs for forest management 

and timber marketing like the National Wild Turkey Federation Wild Turkey 

Woodlands Program and the Nature Conservancy Forest Bank Program. For more 

information on forest, water, and wildlife programs on privately owned lands consult 

“A Landowner’s Guide to Sustainable Forestry in Indiana” (https://www.extension.

purdue.edu/extmedia/FNR/FNR-187.pdf) or visit the Indiana DNR’s forestry web site 

(http://www.in.gov/dnr/forestry/).

Another important trend to watch is the aging of the family forest owners. The 

family legacy of passing land on is a major ownership objective, but it is also a 

major concern for both landowners and natural resource managers. Landowner 

turnover is something that is perpetually happening, but it is also a critical juncture 

for landowners and the land. Forest land is at increased risk of parcelization and 

poor harvesting practices shortly before and after transfer of ownership. With many 

owners being relatively advanced in age, this portends many acres of land passing on 

to the next generation in the not too distant future. There are programs such as Your 

Land Your Legacy (http://masswoods.net/monthly-update/your-land-your-legacydeciding-future-your-land) and Ties to the Land (http://tiestotheland.org) that have 

been implemented to help owners meet their bequest goals, but it is uncertain who 

the future forest owners will be and what they will do with their land.
32 | FOREST FEATURES

Tree Density, Size, and Stocking

Background

How well forests are populated with trees is determined by two measurements: the 

trunk diameter taken at 4.5 feet above the ground, referred to as diameter at breast 

height, and by the number of trees. Generally, as stands mature and trees become larger, 

the number of trees per acre decreases and stand volume increases. The number of 

trees per acre and their diameters are used to determine levels of stocking, which is a 

measure of how well a site is being utilized to grow trees. In Indiana, stocking levels are 

reported for all live trees exclusive of merchantability or for growing-stock trees only. 

Growing-stock trees are economically important and do not include noncommercial 

species (e.g., pawpaw, hawthorn spp., red mulberry, flowering dogwood, and Osageorange) or trees with large amounts of cull (rough and rotten trees). In fully-stocked 

stands, trees use all of the potential of the site to grow. As stands become overstocked, 

trees become overcrowded, growth begins to slow, and mortality increases. In poorly 

stocked stands trees are widely spaced, or if only growing-stock trees are included in the 

stocking calculations, the stands may contain many rough and rotten trees with little 

or no commercial value. Poorly stocked stands can develop on abandoned agricultural 

land or result from major disturbances such as windstorms, disease outbreaks, wildfires, 

or poor harvesting practices. Poorly stocked stands are not expected to grow into a fully 

stocked condition in a reasonable amount of time, whereas moderately stocked stands 

will. Comparing stocking levels of all live trees with that of growing-stock trees shows 

how much of the growing space is being used to grow trees of commercial importance 

and how much is occupied by trees of little or no commercial value. If stands are not 

disturbed, stocking levels increase over time as trees naturally reproduce and grow. As 

disturbances such as harvesting or wind events lower stocking levels, changes in species 

composition, diameter distribution, residual tree quality, and regeneration become of 

increasing concern to forest managers.

Tree diameter measurements are used by FIA to assign a stand-size class to sampled 

stands. The categories are determined by the class that accounts for the most stocking 

of live trees per acre. Sapling or small diameter stands are dominated by trees less 

than 5 inches d.b.h. Poletimber or medium diameter stands have a majority of trees 

with a d.b.h. of 5 inches and larger, but less than the large diameter stands. Sawtimber 

or large diameter stands consist of a preponderance of trees at least 9 inches in d.b.h. 

for softwood species and 11 inches d.b.h. for hardwood species.
 | 33

What we found

The number of trees greater than or equal to 1 inch in diameter increased by 0.8 

percent from 2008 to 2013 (Fig. 23), reaching roughly 2.2 billion trees. This increase is 

not distributed evenly across diameter classes, but has shifted toward larger diameter 

trees (Fig. 24). Saplings (trees 1 to 4.9 inches d.b.h.) showed a 1.7 percent decrease. 

The number of trees in diameter classes less than 16 inches increased by 0.5 percent 

while tree numbers in classes 16 inches and larger increased by 8.3 percent. This is 

also reflected in the continued increase in the average diameter for all trees 5 inches 

d.b.h. and larger on timberland which increased from 9.7 inches in 1986, to 10.2 

inches in 1998, and 10.5 inches in 2013.

0 

50 

100 

150 

200 

250 

6 8 10 12 14 16 18 20 22 24 26 27+ 

Diameter Class (inches d.b.h.) 

2008 

2013 

0 

250 

500 

750 

1,000 

1,250 

2 4 

Number of Trees (millions) 

Figure 23.—Number of live trees on forest land by diameter class 

and inventory year, Indiana, 2008 and 2013. Error bars represent 1 

standard error or a 68 percent confidence interval around the mean.

-5 

0 

5 

10 

15 

20 

25 

2 4 6 8 10 12 14 16 18 20 22 24 26 27+ 

Change in Numbers of Trees (percent) 

Diameter Class (inches d.b.h.) 

Saplings Poletimber Sawtimber 

Figure 24.—Change in the number of live trees on forest land 

by diameter class, Indiana, 2008 to 2013.
34 | FOREST FEATURES

The shift in tree size has brought about an increase in stands dominated by sawtimbersize trees (Fig. 25). Trends show sawtimber-size stands continuing to increase at the 

expense of poletimber and seedling-sapling-size stands. In 2013, more than three 

quarters (3.7 million acres) of timberland in the State was in sawtimber-size stands. 

Poletimber stands have experienced little change since 1986 and total 684,000 acres in 

2013. Seedling-sapling-size stands and nonstocked timberland continued to decrease 

and currently represent 7.0 percent of timberland (332,000 acres).

0 

1 

2 

3 

4 

Seedling/Sapling* Poletimber Sawtimber 

Timberland Area (million acres) 

Stand-size Class 

1986 

2003 

2013 

*Includes nonstocked stands-40,000 acres

2000 

2005 

2008 

2013 

1986 

1998 

2003 

2013 

Figure 25.—Timberland area by stand-size class and inventory year, 

Indiana. Error bars represent 68 percent confidence interval around 

the mean.

Indiana has the lowest percentage of forest land in seedling-sapling size stands 

(7.1 percent) compared to the surrounding states of Michigan (18.6 percent), Ohio 

(11.6 percent), Kentucky (9.7 percent), and Illinois (7.9 percent). Indiana also has 

the lowest forest land percentage of poletimber size stands (14.7 percent) of the 

surrounding states of Michigan (32.8 percent), Ohio (21.0 percent), Kentucky 

(19.4 percent), and Illinois (15.2 percent). Consequently, Indiana has the highest 

percentage of forest land in sawtimber-size stands (77.4 percent) when compared to 

the surrounding states of Illinois (75.6 percent), Kentucky (70.6 percent), Ohio (66.6 

percent), and Michigan (47.9 percent). 

In Indiana, 2 million acres (43 percent) of timberland are fully stocked or overstocked 

with live trees, nearly 2 million acres (42 percent) have medium stocking, and 688,000 

acres (15 percent) are either poorly stocked or nonstocked (Fig. 26). Since 1986, 

stocking has shifted from overstocked toward fully stocked and medium stocked 

levels. Acreage in fully stocked and overstocked stands has decreased by 1.2 million 

acres since 1986 when nearly 75 percent (3.2 million acres) was either overstocked 

(765,000 acres) or fully stocked (2.4 million acres). Now, more than half of all stands 
 | 35

are less than fully stocked with live trees. When considering only the commercially 

important growing-stock trees, the area with poor stocking is 986,000 acres, or twice 

the area when including all trees (Fig. 27). Most of the acreage in these stands is in 

older age classes or in stands dominated by large trees (Fig. 28). Nearly 80 percent 

of the acreage is in age classes more than 40 years old, and 78 percent is in large 

diameter stands (Fig. 29). Indiana forests are maturing. Currently, nearly half (48 

percent) of the stands are over 61 years of age.

0 

1 

2 

3 

Nonstocked Poorly 

stocked 

Medium 

stocked 

Fully

stocked 

Overstocked 

Timberland Area (million acres) 

Stocking Class 

1986 

2003 

2013 

Figure 26.—Area of timberland by stocking class and inventory year, 

for all live trees, Indiana. Error bars represent 1 standard error or a 68 

percent confidence interval around the mean.

0 

1 

2 

3 

Poorly/

nonstocked 

Medium 

stocked

Fully

stocked 

Overstocked 

Forest Land Area (million acres) 

Stocking Class 

Based on 

all live trees 

Based on 

growing-stock 

trees 

Figure 27.—Area of forest land by stocking class based on all 

live trees, and on growing-stock trees, Indiana, 2013. Error bars 

represent 1 standard error or a 68 percent confidence interval around 

the mean.
36 | FOREST FEATURES

0.0 

0.1 

0.2 

0.3 

0.4 

0.5 

0.6 

0.7 

0.8 

0.9 

1.0 

0-20 21-40 41-60 61-80 81-100 100+ 

 Forest Land Area (million acres) 

Age Class (years) 

Poorly/nonstocked 

Medium stocked 

Fully/overstocked 

Figure 28.—Area of forest land by stand-age class and stocking level for 

growing-stock trees only, Indiana, 2013.

0.0 

0.2 

0.4 

0.6 

0.8 

1.0 

1.2 

1.4 

1.6 

1.8 

Small diameter Medium diameter Large diameter 

Forest Land Area (million acres) 

Stand-size Class 

Poorly/nonstocked 

Medium 

Fully/overstocked 

Figure 29.—Area of forest land by stand-size class and stocking level for 

growing-stock trees only, Indiana, 2013.

What this means

The continued shift to larger size trees and the increase in area of sawtimber-size 

stands indicates that Indiana forests are maturing. Increases in tree size have also 

brought about an overall improvement in stocking levels and contribute to Indiana’s 

economy by supporting the timber products industry. The 2 million acres in fullystocked and overstocked stands present opportunities for forest management. 

Managing these stands can keep them growing optimally.

Fifty-six percent of forest land is less than fully stocked with trees, but when only 

growing-stock trees are considered, this level increases to 65 percent. The broad extent 

of these less than fully-stocked stands indicates that a large amount of disturbance, 
 | 37

both natural and human-caused, has occurred in Indiana forests. The nearly one 

million acres of forest land that are poorly stocked or nonstocked represents a loss 

of potential growth. Trees in these stands are either widely spaced or are low value 

trees that occupy growing space that could otherwise be used to grow quality timber. 

These stands may have originated from farmland that reverted to forest or from poor 

harvesting practices. Poorly stocked stands include an estimated 700,000 acres that 

are more than 40 years old and dominated by medium and large size trees. These 

stands are likely the result of poor harvesting practices (e.g., high grading), although 

they could occur from using acceptable forestry practices such as shelterwood or seed 

tree harvesting methods to regenerate the stands. Poorly stocked stands represent a 

challenge to forest managers because they contain little value to pay for improvement, 

and although they are considered a sign of past poor management, they still provide 

wildlife habitat. The difference in stocking levels when using only growing-stock trees 

versus all live trees implies that many low-quality trees have been left behind after 

harvesting. These cull and noncommercial species occupy space and inhibit effective 

new growth of more valuable trees. Retaining large amounts of residual trees during 

harvesting also impedes the start of new age classes that are important to maintaining 

forest health and future timber supplies.

The 7 percent of forest land in seedling-sapling stands is likely the result of farmland 

reverting to forest or timber harvesting using even-age management. Currently, 

agricultural lands reverting to forest and the participation of farmers and private 

forest landowners in conservation programs are two major sources of seedling-sapling 

stands. Slowing these processes would likely continue the decline in this stand-size 

class. Young stands offer opportunities for further increases in Indiana’s timber 

resource but also provide unique early successional wildlife habitat features that are 

not provided by sawtimber-size stands. Across the northeastern states, the number 

of animal species that require early-successional habitats are declining because of 

changing habitats. Besides offering diverse habitats and providing a steady flow of 

wood products, forests that contain stands of various sizes may be more resistant to 

devastating outbreaks of insects and diseases. The shift to denser levels of stocking 

indicates that growing conditions in Indiana are becoming crowded, and therefore 

more shaded. 
38 | FOREST FEATURES

Forest Composition

Background

Long-term changes in forest composition can alter wildlife habitats and affect the 

value of the forest for timber products. The species composition of a forest is the 

result of the interaction of climate, soils, disturbance, competition among tree 

species, and other factors over time. In the last 60 years, low levels of selective timber 

harvest on public lands, partial-cutting and high grading on private lands, and a lack 

of fire as a periodic disturbance regime have reduced oak recruitment in Central 

Hardwood forests, particularly on high quality (mesic) sites (Hicks 1998, IN DNR 

2008, Schmidt et al. 2000, Van Lear and Watt 1993, Woodall et al. 2005). Other 

factors that contribute to poor oak and hickory regeneration include understory 

growing conditions that favor more shade tolerant hardwoods, preferential browsing 

of oak seedlings by white-tailed deer (Odocoileus virginianus), and the low intensity 

harvesting practices that leave only small gaps in the canopy (Johnson et al. 2002). 

Without periodic understory disturbances to reduce competition from more shade 

tolerant and less fire-tolerant species such as sugar maple, oaks and hickories are 

eventually out-competed when openings or large gaps are created in the canopy 

(Hicks 1998, IN DNR 2008, Lorimer 1993). Unless sufficient advance regeneration 

is in place when openings are made in the canopy, rapidly establishing and faster 

growing species such as yellow-poplar quickly overtop oak seedlings and dominate 

the site (Johnson et al. 2002). 

Forest attributes recorded by FIA that describe forest composition include foresttype group and numbers of trees by species and size. Forest types describe groups of 

species that frequently grow in association with one another and dominate the stand. 

Similar forest types are combined into forest-type groups. Changes in area by forest 

type are driven by changes in the species composition of the large diameter trees. 

These large trees represent today’s forest, and the composition of the smaller diameter 

classes represents the future forest. Comparisons of species composition by size can 

provide insights into future changes in overstory species.

What we found

The 2013 inventory identified 95 tree species (see Appendix 1), 50 forest types, and 

12 forest-type groups across Indiana. Hardwoods are the dominant tree species group 

and oak/hickory is the most common forest-type group, occupying 72 percent of 

forest land, the bulk of which resides in the white oak/red oak/hickory forest type 
 | 39

(1.5 million acres). The oak/hickory forest-type group consists of white oak, northern 

red oak, hickory species, white ash, walnut, yellow-poplar, and red maple. Softwoods 

alone occupy 103,000 acres. The oak/pine forest-type group occupies almost 160,000 

acres, which represents 3 percent of the forest land. These broad species groups have 

undergone little change in extent since 2008. Indicative of a maturing (aging) forest, 

the white oak/red oak/hickory forest type is found primarily in the large standsize class (Fig. 30). The cherry/white ash/yellow-poplar forest type is less common 

(470,000 acres) as is the mixed upland hardwoods forest type (380,000 acres). Both 

show similar distributions across stand-size classes with a large proportion in the 

medium and large diameter classes. The sugar maple/beech/yellow birch forest-type 

group is relatively abundant (211,000 acres) and occurs mostly in large stand-size 

classes. 

0 400 800 1,200 1,600 

Sugarberry/hackberry/

elm/green ash

Sugar maple/beech/

yellow birch

Mixed upland hardwoods 

Cherry/white ash/

yellow-poplar

White oak/red oak/

hickory

Forest Land Area (thousand acres) 

Forest Types 

Large diameter 

Medium diameter 

Small diameter 

Figure 30.—Area of forest land by five most common forest types and 

stand-size class, Indiana, 2013. Error bars represent 1 standard error or 

a 68 percent confidence interval around the mean.

Timberland area in Indiana is approximately 4.7 million acres or 19 percent of 

Indiana’s land area and has increased by 16 percent from 1950 to 2013. Over the 

same period the volume of growing stock on timberland increased by more than 3.5 

times, from 2.6 to 9.1 billion cubic feet; the proportional volume increase was slightly 

less if expressed in sawtimber board-foot volume (Fig. 31). Between 1950 and 2013 

the proportion of all timberland in the sawtimber-size class (i.e., stands where the 

overstory trees are predominantly >11 inches d.b.h.) increased from 52 to 78 percent 

(Fig. 32). This increase in size class and volume is mostly due to the maturing of the 

forest resource and indicates disturbances to the main canopy are either infrequent or 

of low intensity (e.g., harvest by individual tree selection). 
40 | FOREST FEATURES

0 

5 

10 

15 

20 

25 

30 

35 

40 

1950 

1967 

1986 

1998 

2003 

2013 

Timberland 

Area

(million acres)

Growing-stock

Volume

(million ft3

)

Sawtimber 

Volume

(million bd.ft.)

Figure 31.—Timberland area, growing-stock volume, and sawtimber 

volume (International 1⁄4-inch rule) by inventory year, Indiana.

0 25 50 75 100 

1950 

1967 

1986 

1998 

2003 

2013 

Percent 

Inventory Year 

Seed/Sapling 

Pole 

Sawtimber 

Figure 32.—Area of timberland by stand-size class and 

inventory year, Indiana.

White ash, the species with the most trees in the seedling-size class (trees less than 1 

inch d.b.h. and at least 1 foot in height), represents about 20 percent of all seedlings, 

followed by sugar maple, pawpaw, sassafras, and eastern hophornbeam (Fig. 33). 

Northern red and white oaks occur at low densities in the seedling-size class, ranking 

25th and 11th, respectively. Bitternut and shagbark hickories also rank low at 19th 

and 20th, respectively.
 | 41

0 1,000 2,000 

Northern red oak 

Boxelder 

Sweetgum 

Pignut hickory 

Eastern redbud 

Shagbark hickory 

Bitternut hickory 

Black oak 

Blackgum 

Hackberry 

American hornbeam, musclewood 

Red maple 

Slippery elm 

Yellow-poplar 

White oak 

American elm 

Flowering dogwood 

Green ash 

Black cherry 

American beech 

Eastern hophornbeam 

Sassafras 

Pawpaw 

Sugar maple 

White ash 

Number of Seedlings (millions) 

Species 

Figure 33.—Most numerous species ranked by number of 

seedlings (trees less than 1 inch d.b.h. and at least 1 foot tall), 

Indiana, 2013. Error bars represent 1 standard error or a 68 

percent confidence interval around the mean.

The ranking of saplings is somewhat different than that of seedlings (Table 1). Sugar 

maple is the most numerous sapling followed by American elm and American beech. 

Oak and hickory species rank poorly in this size class. White oak declined 18.2 

percent and northern red oak saplings declined by nearly a third since 2008. Saplings 

that had the largest percentage gains since 2008 are black walnut (33 percent), red 

mulberry (32 percent), silver maple (25 percent), and pawpaw (24 percent). Species 

with the largest decreases in sapling numbers since the previous inventory are 

sweetgum (48 percent), American basswood (46 percent), black oak (36 percent), 

and northern red oak (32 percent). Shagbark hickory and black cherry also showed 

modest declines of 10 and 16 percent, respectively. The proportion of oaks in the 

seedling and sapling-size classes lagged well behind that of maple and beech. Even 

yellow-poplar, a shade intolerant species, is approximately as common in the small 

tree-size classes as the entire white oak or red oak groups.
42 | FOREST FEATURES

Rank 

2013

Rank 

2008 Species

Number of saplings 

2013 (millions)

Percent change 

2008-2013

1 1 Sugar maple 279 0

2 2 American elm 106 -0.5

3 4 American beech 98 14.2

4 5 Sassafras 88 7.2

5 3 Flowering dogwood 77 -15.9

6 7 Red maple 77 1.8

7 6 Black cherry 69 -16.2

8 8 White ash 69 -3.3

9 9 Eastern redcedar 47 -15.3

10 13 Hackberry 46 18.9

11 15 American hornbeam, musclewood 40 10.8

12 14 Eastern hophornbeam 38 3.4

13 12 Yellow-poplar 37 -7

14 18 Pawpaw 36 24

15 11 Eastern redbud 33 -22.7

16 17 Ohio buckeye 31 8.7

17 10 Sweetgum 29 -48.1

18 21 Green ash 27 16.9

19 16 Slippery elm 25 -22

20 22 Boxelder 24 10.3

21 20 Blackgum 23 -6.5

22 19 Shagbark hickory 23 -10

23 24 Hawthorn spp. 22 13.4

24 29 Black walnut 16 33.1

25 23 Black oak 15 -36

26 27 Bitternut hickory 14 1.9

27 30 Red mulberry 14 31.6

28 25 American basswood 12 -46.2

29 28 White oak 12 -18.2

Note: An additional 51 species make up less than 10 percent of the total number of saplings.

Table 1.—Ranking of number of saplings (trees 1 to 4.9 inches d.b.h.) by species for the 2013 and 2008 inventories, 

the total number of stems in the 2013 inventory, and the percent change from 2008 to 2013, Indiana

For trees of poletimber size and larger (5 inches d.b.h. and larger), sugar maple still 

dominates, followed by yellow-poplar and red maple (Fig. 34). If only trees in the 18-

inch and larger diameter classes are considered, yellow-poplar is the most numerous 

species followed by white oak, red maple, sugar maple, and black oak. Oaks and 

hickories are better represented in diameters larger than 11 inches (Fig. 35) and make 

up 23 and 10 percent of the total number of trees in that class, respectively.

In the current inventory, oaks represent more than 34 percent of trees 20 inches and 

larger in diameter, but less than 4 percent of trees in the 2- and 4-inch diameter classes 

(Fig. 36). Hickories make up less than 3 percent of trees in the 2- and 4- inch diameter 

classes. Conversely, maple species have a disproportionate share of trees in the 2- and 

4-inch diameter classes amounting to 23 percent, compared to their presence in the 

larger diameter classes at 11 percent for trees 20 inches d.b.h. and larger. 
 | 43

18 

18 

20 

21 

24 

26 

27 

27 

40 

72 

14 

15 

14 

18 

16 

25 

18 

30 

50 

16 

18 

11 

17 

27 

9 

11 

23 

44 

0 10 20 30 40 50 60 70 

American elm* 

Sassafras 

Black walnut 

Shagbark hickory 

White oak 

Black cherry 

White ash 

Red maple 

Yellow-poplar 

Sugar maple 

Number of Trees (millions) 

Species 

Species 

*Includes slippery and American elm 

A 

9 

10 

10 

11 

12 

13 

13 

15 

16 

17 

10 

10 

8 

8 

8 

8 

13 

11 

16 

19 

10 

8 

7 

7 

8 

5 

12 

8 

16 

17 

0 5 10 15 20 

American sycamore 

Bitternut hickory 

Silver maple 

Green ash 

American beech 

Hackberry 

Northern red oak 

Eastern redcedar 

Pignut hickory 

Black oak 

Number of Trees (millions) 

1986 

1998 

2013 

1986 

1998 

2013 

B 

Figure 34.—Most abundant species ranked by the numbers of trees 

5.0 inches d.b.h. and larger in 2011, with estimates for number of 

trees in 1986 and 1998 on timberland, Indiana. Ten most abundant 

species are depicted in A, with the second group of 10 in B. (Note 

the difference in the x-axis scale for A and B.)
44 | FOREST FEATURES

0

20

40

60

80

100

Individual Species as a Percentage

 of Total Number of Trees in Class

Diameter Class (inches d.b.h.)

Oaks

Red maple

Sugar maple

Hickory

American beech

Ash

Yellow-poplar

Black cherry

Elm

All other species

2 4 6 20 21.0-

28.9

8 10 12 14 16 18 29.0+

Figure 35.—Species composition by diameter class on forest land, 

Indiana, 2013.

0 

10 

20 

30 

40 

50 

Percentage of Trees in Class 

Diameter Class (inches d.b.h.) 

Oaks 

Maples 

2 

4 

6 

8 

10 

12 14 

16 18 

20 

21.0-28.9 

29.0+ 

Figure 36.—Oaks and maples on forest land as a percentage of all 

trees by diameter class, Indiana, 2013.

In 1967, the proportion (or the total number) of red oaks and proportion of white 

oaks each exceeded that of maple and beech for diameter classes larger than about 8 

inches d.b.h. (Fig. 37A). By 2013, the proportion of maples and beech increased in 

smaller diameter classes, and the point of intersection increased to approximately 18 

inches d.b.h. (Fig. 37B).
 | 45

0 

5 

10 

15 

20 

25 

30 

35 

0 5 10 15 20 25 30 

Percentage of Total 

Diameter Class (inches d.b.h.) 

0 

5 

10 

15 

20 

25 

30 

35 

0 5 10 15 20 25 30 

Percentage of Total 

Diameter Class (inches d.b.h.) 

Red oaks 

White oaks 

Maple and 

beech 

B 2013 

Red oaks 

White oaks 

Maple and beech 

A 1967 

Figure 37.—Changes in the size distribution of trees in the red oak, white 

oak, and maple-beech species groups, Indiana, 1967 (A) and 2013 (B). 

Arrow indicates diameter class at which three species groups intersect.

What this means

The area of the oak/hickory forest-type group and other major forest-type groups 

has remained stable since 1986, but this does not fully depict the underlying shifts in 

individual species. The species composition of the seedling and sapling-size classes has 

future forest composition implications. Sixteen percent of all trees on timberland are 

now sugar maple, and no single oak or hickory species ranks in the top 15 species in 

terms of total number of trees. Yet oak species as a group have more volume than any 

other species group, and oaks dominate in the largest diameter classes. The current 

trajectory away from dominance by oaks and hickories has implications for biodiversity, 

wildlife, recreation, and the forest products industry. Widespread losses of oak and 

hickory would directly and indirectly affect multitudes of species, reduce native 

biodiversity, and drive community-level shifts and alterations (Fralish 2004, IN DNR 
46 | FOREST FEATURES

2008, McShea et al. 2007, Ostfeld et al. 1996, Rodewald 2003). Throughout Indiana and 

the entire Central Hardwood region, oak/hickory forests are maturing and in many 

places shifting to different forest types (Abrams 2003, Aldrich et al. 2005, McCune and 

Cottam 1985, Schmidt et al. 2000, Woodall et al. 2005). As maturing oaks and hickories 

die, they often are replaced by other competing species, such as sugar maple and 

yellow-poplar, rather than young oaks or hickories. Driving these shifts are significant 

reductions or even failures in oak/hickory regeneration (Aldrich et al. 2005, IN DNR 

2008, Lorimer 1993, Woodall et al. 2005).

Maples will play an increasing role in the future forests of Indiana. Though oak and 

hickory seedlings can still be found in Indiana forests, statewide there typically are 

substantially more competitors, such as sugar maple, that outnumber any single oak 

or hickory seedling species by a factor of 4 to 1. In terms of number, sugar maples 

dominate, with three times as many trees as any other species. This will likely cause 

the area occupied by the oak/hickory forest-type group to undergo a long-term 

decline and be replaced by the beech/maple/birch group. 

Large increases in the numbers of sapling-size American hornbeam and eastern 

hophornbeam may be due to these species responding to gaps created by partial harvests 

and other disturbances. Both of these species are tolerant of shade and grow well in 

the understory. They may also be filling niches vacated by flowering dogwoods that are 

dying from dogwood anthracnose (Discula destructiva Redlin), a fungal disease.

If the perpetuation of the oak/hickory forest type is a primary goal for the forests of 

Indiana, forest land owners and natural resource managers will need new management 

strategies and practices to change the current trends, which could take decades to alter. 

To assure this composition and structure is maintained, periodic inventories at the stand 

and system level must be taken, with management treatments applied as necessary. 

Adequate timber harvest levels with emphasis on methods, timing, and follow-up 

silvicultural treatment would assist problematic oak and hickory regeneration and, 

ultimately, recruitment. Placement and size of harvest openings is critical to supporting 

oak and hickory seedlings in concert with sufficient understory treatment to reduce 

competition from other species. Due to the immediacy and severity of the problem, 

relying on a “hands-off” approach to oak and hickory regeneration is not likely to be 

successful in the long-term; some form of active management is necessary to emulate 

natural regeneration (IN DNR 2008). One guide, the Indiana Department of Natural 

Resources, Division of Forestry offers a treatise on the problems and challenges facing 

forest ecologists and land managers as they design harvest and vegetation management 

regimes to successfully regenerate oak and hickory in the Central Hardwood region (IN 

DNR 2008). It features an extensive array of research studies and programs currently 

underway on state forest properties that investigate the site-specific challenges to oak and 

hickory regeneration. The results of the long-term studies are expected to guide future 
 | 47

forest management activities on Indiana’s State forests and provide a model for successful 

oak/hickory management throughout the State and region. More information on Indiana 

forest regeneration can be found in the regeneration section later in this report.

Tree Volume

Background

The assessment of the volume of live trees provides information on trends in the 

resource, the potential uses of that wood, and its economic value. Current volumes 

and changes in volume over time can characterize forests and reveal important 

resource trends. FIA reports tree volume in several ways: sound and net volume of 

live trees, growing stock and sawtimber volume of live trees of commercial species, 

and biomass in dry tons. Each of these measures characterizes the wood resource in 

a different way and provides insights into its use and management. And, as discussed 

in the next section, biomass estimates are a means for quantifying carbon storage. 

Because of changes in procedures, comparisons to past inventories are less consistent 

for some measures than others. 

What we found 

Eighty-five percent (9.1 billion cubic feet) of the live sound wood volume is 

categorized as growing-stock volume (Fig. 38). Also contained within these growingstock trees is an additional 144.5 million cubic feet categorized as sound cull. On 

timberland, rough and rotten trees account for a combined 1.1 billion cubic feet and 

represent 9 percent and 1 percent of total sound volume, respectively. 

Growing-stock volume 

on timberland 

85% 

Sound cull in growing-stock 

trees on timberland 

1% 

Cull trees (rough and rotten) 

on timberland 

10% 

Total volume on reserved 

and other forest land 

4% 

Total sound volume = 10.8 billion cubic feet 

Figure 38.—Components of live sound wood volume on forest 

land, Indiana, 2013.
48 | FOREST FEATURES

Since 1986, the net volume of live trees on Indiana timberland has steadily increased 

and now totals over 10 billion cubic feet, a 6 percent increase from 2008 (Fig. 39). 

On a per-acre basis, this volume averages 2,137 cubic feet per acre, a 51 percent 

increase since 1986. Volume has been shifting toward the sawtimber-size classes (Fig. 

40). The most recent inventory shows that since 2008, volume has increased in all 

diameter classes (Fig. 41). Trees less than 11 inches now make up about a third of 

the total volume, 1 percent less than in 2008. All of the gains in volume were in trees 

large enough to produce saw logs (≥11 inches d.b.h. for hardwood species), which 

reflects the changes in the number of trees discussed previously. Recent gains are a 

continuation of the increases that have been occurring over the last 60 years. 

4 

5 

6 

7 

8 

9 

10 

11 

1985 1995 2005 2015 

Volume (billion ft3

)

Inventory Year 

Figure 39.—Net volume of live trees on timberland by inventory year, Indiana. 

0 

1 

6 8 10 12 14 16 18 20 22 24 26 28 30 

Live Volume (billion ft3

)

Diameter Class (inches d.b.h.) 

2008 

2013 

Sawtimber 

size 

Poletimber 

 size 

Figure 40.—Net volume of live trees on forest land by diameter class, 

Indiana, 2008 and 2013. Error bars represent 1 standard error or a 68 

percent confidence interval around the mean.
 | 49

0 

5 

10 

15 

20 

25 

30 

6 8 10 12 14 16 18 20 22 24 26 27+ 

Change in Volume (percent) 

Diameter Class (inches d.b.h.) 

Total volume + 6% 

Figure 41.—Percent change in net volume of live trees on forest 

land by diameter class, Indiana, 2008 to 2013.

In the current inventory, net volume of sawtimber trees on timberland was highest in 

the Knobs Unit (10.2 million board feet), followed by the Northern Unit (6.4 million 

board feet), Lower Wabash Unit (5.1 million board feet), and Upland Flats Unit (2.9 

million board feet) (Fig 42). Yellow-poplar continues to be the most voluminous species 

followed by sugar maple and white oak (Fig. 43). Volume increased in all three species. 

Black cherry had the greatest percentage increase in volume at 17 percent. Although 

volume increased in most major species, eastern cottonwood and pignut hickory 

showed decreases in volume. Sixteen species compose 76 percent (7.9 billion cubic feet) 

of the live volume found throughout Indiana (Fig. 43). The ten most common species 

by volume differ somewhat by unit and represent the following percentage of the live 

volume: Lower Wabash (62 percent), Knob (73 percent), Upland Flats (79 percent), and 

Northern Units (51 percent) (Fig. 44). In the Lower Wabash Unit, the decrease in black 

oak volume is caused by oak decline and associated drought periods, and the decrease in 

white ash volume is attributed to emerald ash borer. 

10.2 

5.1 

6.4 

2.9 

24.6 

0 5 10 15 20 25 

Knobs 

Lower Wabash 

Northern 

Upland Flats 

All Units 

Volume (million board feet) 

FIA Unit 

Figure 42.—Net volume of growing stock sawtimber trees on timberland, 

in million board feet (Doyle log rule), by FIA unit, Indiana, 2013.
50 | FOREST FEATURES

0 500 1,000 1,500 

Bitternut hickory 

Eastern cottonwood 

American beech 

Silver maple 

Pignut hickory 

Black walnut 

Black cherry 

Shagbark hickory 

American sycamore 

Northern red oak 

Red maple 

Black oak 

White ash 

White oak 

Sugar maple 

Yellow-poplar 

Live Volume (million ft3

)

Species 

2008 

2013 +1% 

+17% 

+15% 

-1% 

+16% 

+1% 

+6% 

+13% 

+1% 

+4% 

+3% 

+5% 

+11% 

+7% 

+7% 

-8% 

Figure 43.—Live volume of selected species on forest land, Indiana, 2008 

and 2013. Percent change shown to right of bar pairs. Error bars represent 

1 standard error or a 68 percent confidence interval around the mean.

Figure 44.—The 10 most common species in each FIA unit, ranked by 

2013 live volume followed by percent of forest land live volume in FIA unit 

and percent change in volume (+ or -) from 2008 to 2013, Indiana.

Northern

Sugar maple 8% (+3%)

White ash 7% (+9%)

Eastern cottonwood 6% (-28%)

Black cherry 6% (+22%)

Black walnut 5% (+20%)

Northern red oak 4% (+23%)

American sycamore 4% (-5%)

Green ash 4% (+3%)

Black oak 4% (+9%)

Silver maple 4% (+35%)

Knobs

Yellow-poplar 17% (+13%)

Sugar maple 13% (0%)

White oak 11% (-4%)

Black oak 8% (+4%)

Red maple 5% (+15%)

Pignut hickory 4% (+1%)

American beech 4% (-5%)

Northern red oak 4% (-10%)

Chestnut oak 4% (+4%)

White ash 4% (-4%)

Lower Wabash

Yellow-poplar 15% (-2%)

Sugar maple 9% (-8%)

American sycamore 6% (+9%)

White oak 6% (-6%)

Silver maple 5% (+25%)

Northern red oak 5% (+20%)

White ash 4% (-9%)

Eastern cottonwood 4% (+24%)

Red maple 4% (+1%)

Black oak 4% (-40%)

Upland Flats

Sugar maple 13% (+37%)

White ash 13% (+24%)

Yellow-poplar 12% (+33%)

Red maple 9% (+44%)

White oak 7% (+42%)

American sycamore 6% (+21%)

Eastern redcedar 5% (+19%)

Black walnut 5% (+9%)

Shagbark hickory 5% (+15%)

Bitternut hickory 4% (+17%)
 | 51

Sawtimber volume on timberland increased by nearly 5 percent and totals 36.1 billion 

board feet (International 1⁄4-inch rule). Yellow-poplar is the leading sawtimber species, 

by volume, followed by sugar maple, white oak, black oak, and white ash (Fig. 45). White 

ash is expected to fall from this list of leading sawtimber species, by volume, as ash trees 

die within the next 10 years as emerald ash borer completes it spread across Indiana. 

Black cherry (+46 percent) followed by silver maple (+34 percent) and walnut (+14 

percent) had the largest percentage increases in board-foot volume since 2008 while 

eastern cottonwood (-9 percent), American beech (-7 percent), and black oak 

(-6 percent) had the largest decreases. 

0 1 2 3 4 5 6 7 

Bitternut hickory 

Black cherry 

American beech 

Silver maple 

Black walnut 

Eastern cottonwood 

Pignut hickory 

Red maple 

Shagbark hickory 

American sycamore 

Northern red oak 

White ash 

Black oak 

White oak 

Sugar maple 

Yellow-poplar 

Sawtimber Volume (billion board feet) 

Species 

2008 

2013 

+13% 

+6% 

+2% 

+6 

Total board foot volume 

increased by 4.7 percent 

+2% 

+9% 

-6% 

+8% 

+9% 

-2% 

-9% 

14% 

34% 

-7% 

46% 

-2% 

Figure 45.—Sawtimber volume in board feet (International 1⁄4-inch 

rule) on timberland by species, Indiana, 2008 and 2013. Percent 

change shown to the right of the bar pairs. Error bars represent 1 

standard error or a 68 percent confidence interval around the mean.

All units showed gains in cubic foot and board-foot volumes. Average board-foot volume 

per acre of timberland were highest in the Knobs Unit and lowest in the Upland Flats 

Unit; however, the Upland Flats Unit had the largest percentage increase in average cubic 

foot volume per acre of forest land (8 percent) as well as in average sawtimber board-foot 

volume per acre of timberland (15 percent) since 2008 (Fig. 46).

Statewide, shifts in the relative dominance of tree species are indicated by changes in 

volume over the last 25 years. Although white oak volume increased by 228 million cubic 

feet between 1986 and 2013 and red oak increased by 460 million cubic feet, yellow-poplar 

boomed and had a 179 percent increase in growing-stock volume, increasing by 773 

million cubic feet (Fig. 47).
52 | FOREST FEATURES

State

2,137 ft3

/acre (4%)

7,938 bd ft/acre (6%)

Northern

2,078 ft3

/acre (5%)

7,156 bd ft/acre (10%)

Lower Wabash

2,240 ft3

/acre (3%)

8,401 bd ft/acre (3%)

Knobs

2,199 ft3

/acre (2%)

8,707 bd ft/acre (3%)

Upland Flats

1,945 ft3

/acre (8%)

6,742 bd ft/acre (15%)

Figure 46.—Average cubic-foot (ft3) volume per acre of live trees 

on forest land and average board-foot (bd ft) volume per acre on 

timberland, by FIA unit, 2013, and percent change in volume per acre, 

Indiana, 2008 to 2013.

0 200 400 600 800 1,000 1,200 1,400 

Red oak 

White oak 

Yellow-poplar 

Hickory 

Hard maple 

Ash 

Soft maple 

Sycamore 

Cottonwood 

Black walnut 

Beech 

Black cherry 

Net Volume (thousand ft3

)

Species

1986 

1998 

2003 

2013 

53% 

118% 

58% 

29% 

179% 

182% 

183% 

90% 

94% 

97% 

123% 

57% 

Figure 47.—Growing-stock volume by species/species group and 

inventory year, Indiana. Percent change in growing-stock volume from 

1986 to 2013 is shown beside bars.
 | 53

The Forest Service commonly reports sawtimber board-foot volume in International 1⁄4-inch 

rule. In Indiana, the Doyle log rule is commonly used. Due to State and local interest, the 

following sawtimber volume discussion is presented using the Doyle log rule. To convert 

between Doyle log rule and International 1⁄4-inch rule, see Appendix 2 or consult Smith 1991. 

Current statewide estimates of sawtimber net volume by species reflect the trend discussed 

above, with the following species making up the indicated percentage of the total estimated 

sawtimber net volume of 24.6 billion board feet (Doyle log rule): yellow-poplar (15.7%), 

white oak (8.6%), sugar maple (8.4%), black oak (6.2%), northern red oak (5.9%), American 

sycamore (5.7%), white ash (5.3%), and eastern cottonwood (4.3%). Collectively these eight 

species make up more than 60 percent of the total net sawtimber volume. Yellow-poplar 

dominates and has nearly twice the sawtimber volume of any other species. Sugar maple and 

yellow-poplar dominate in the smallest hardwood sawtimber diameter class (11.0 to 12.9 

inches) while yellow-poplar, white oak, black oak, northern red oak, and American sycamore 

dominate in the larger diameter classes (25 inches plus). Eastern cottonwood, American 

sycamore, followed by silver maple, red maple, black oak, pin oak, and white oak compose 

the bulk of tree species over 37 inches in diameter (Table 2). The 25 most common species 

shown in Table 2 make up more than 93 percent of the State’s total net sawtimber volume.

Table 2.—Net volume of the 25 most common sawtimber trees on timberland (Doyle log rule) by species and 

diameter class, Indiana, 2013

Species name

9.0-

10.9

11.0- 

12.9

13.0-

14.9

15.0-

16.9

17.0-

18.9

19.0- 

20.9

21.0- 

24.9

25.0- 

28.9

29.0- 

32.9

33.0- 

36.9 37+

All 

Classes 

-------------------------------- million board feet -----------------------------

Yellow-poplar 189 309 417 573 630 756 742 167 88 3,872

White oak 83 153 244 327 347 412 277 169 70 33 2,116

Sugar maple 240 316 400 343 288 334 83 62 2,066

Black oak 59 94 132 270 201 442 194 101 44 1,537

Northern red oak 40 72 127 199 208 370 183 173 58 22 1,454

American sycamore 34 69 114 121 128 330 294 170 81 60 1,400

White ash 90 144 174 203 146 311 175 17 18 23 1,301

Eastern cottonwood 11 18 43 69 83 154 240 183 164 64 1,027

Shagbark hickory 99 132 159 167 130 103 53 17 859

Red maple 91 99 116 88 119 156 91 31 18 46 854

Pignut hickory 75 112 146 153 115 87 23 16 727

Silver maple 42 50 73 96 72 158 109 76 48 725

American beech 33 40 65 114 102 160 57 61 20 651

Black walnut 79 116 107 126 88 50 27 13 607

Black cherry 93 82 90 79 87 81 28 540

Pin oak 19 35 40 52 39 114 110 38 38 37 523

Bitternut hickory 50 78 74 117 108 60 488

Green ash 40 51 72 37 43 68 17 14 15 17 375

Chestnut oak 18 46 70 56 33 88 26 336

American basswood 21 34 30 41 34 73 15 17 265

Hackberry 35 40 48 27 20 36 19 14 21 261

Eastern white pine 10 21 28 39 72 43 31 11 255

Sweetgum 23 37 27 27 35 68 9 15 241

Chinkapin oak 25 30 31 37 19 61 15 16 234

Sassafras 39 59 44 25 30 10 8 215
54 | FOREST FEATURES

What this means

The shift in species composition and volume is due in part to long-term patterns 

of disturbance and regeneration that favor maples and beech more than oaks. 

Continuous increases in volume have brought Indiana’s forest resources to levels not 

seen in the past 100 years in terms of both total net volume of live trees and boardfoot volume. Over the past six decades the area of Indiana timberland increased from 

4 to nearly 4.9 million acres; over that same period the volume of growing-stock 

timber nearly quadrupled from 2.6 to 9.5 billion cubic feet. This gain, combined 

with a stable forest land base, shows tremendous stewardship and conservation of 

Indiana’s forest resources. Most of the volume is on timberland and in trees that meet 

minimum requirements to qualify as growing-stock trees. Because most volume 

increases have occurred on the larger and more valuable trees (notably black cherry 

and walnut), Indiana forests are likely adding value at a greater rate than increases in 

volume alone indicate. 

In each of the four FIA units, the ten most common species represent over half of the 

total volume, with no one species representing more than a fifth of the total volume 

by unit. There are few areas in Indiana where any one species dominates. This diverse 

mix of species reduces the impact of insects and diseases that target a single species.

The yellow-poplar sawtimber resource in Indiana is booming. Yellow-poplar leads in 

board-foot sawtimber volume and is concentrated in the hill country of the Lower 

Wabash, Knobs, and Upland Flats Units, where it is a valuable part of the timber 

resource. Today, yellow-poplar is the most common tree species in Indiana by 

volume, and it has experienced a state-wide growth in volume that is more than four 

times that of any oak species over the last 25 years. 

The Northern Unit is experiencing emerald ash borer mortality. As of 2013, all ash in 

the eastern half of the Northern Unit were dead or dying.

On flood plains, eastern cottonwood requires moist seedbeds or flood disturbances 

(immersion in water) to reproduce. As the cottonwoods age, a lack of this type 

of disturbance and poor site conditions may result in little reproduction. As a 

consequence, the eventual decreases in eastern cottonwood sawtimber volume will 

result in volume increases by silver maple, a common associate. 
 | 55

Biomass

Background

Trees play an important role in the world’s carbon cycle. They act as a sink for carbon, 

removing it from the atmosphere in the form of carbon dioxide (a greenhouse gas) 

and storing it as cellulose. In this role, forests help mitigate the effect of burning fossil 

fuels and the resulting increase of carbon dioxide in the atmosphere. Indiana forests 

contribute significantly to the sequestration of carbon dioxide due to increases in tree 

volume. 

Tree biomass, a measure of how much carbon is being stored in trees on forest land, 

is the total weight of both live and dead trees, including branches, roots, and stumps. 

Typically the carbon content of biomass is equal to half the biomass weight measured 

in dry tons. Estimates of biomass are important for knowing not only the amount of 

carbon stored but also the potential amount of biomass available for energy uses.

What we found 

Aboveground biomass of all live trees in Indiana forests equals 270.4 million dry 

tons and averages 55.5 tons per acre. The greatest portion (66 percent) is found in 

the merchantable boles of commercially important trees representing growing-stock 

volume (Fig. 48). It is this component that can be converted to high value wood 

products. Other portions of tree biomass are underutilized and can be considered as 

potential sources of fuel for commercial power generation. Biomass in live trees has 

increased by 5 percent since 2008 and is distributed throughout the State, with the 

largest concentrations in the southern tier of Indiana (Fig. 49).

Cull trees 

10% 

Saplings 

5% 

Stumps 

4% 

Growing-stock volume 

66% 

Tops and branches of 

growing-stock trees 

15% 

Figure 48.—Components of tree biomass on forest land, Indiana, 2013.
56 | FOREST FEATURES

Figure 49.—Distribution of live-tree and sapling biomass on forest land, Indiana, 2013.

Northern

Upland 

Flats

Knobs

Lower 

Wabash

Processing note: This map was 

produced by linking plot data to 

MODIS satellite pixels (250 m) 

using gradient nearest neighbor 

techniques.

Live Biomass 

on Forest Land 

(oven-dry tons/acre)

<10

10 to 24

25 to 50

>50
 | 57

What this means 

Indiana forests are accumulating substantial biomass. These stores of carbon will 

receive increasing attention as the Nation seeks sources of renewable energy and ways 

to offset carbon dioxide emissions. Because biomass is a renewable source of energy, 

it can help reduce the Nation’s dependence on fossil fuels. Utilizing biomass for fuel 

can provide markets for low grade and underutilized wood. As biomass markets 

develop, forest managers may need to integrate the harvesting of biomass into their 

management plans. 

The steady rates of increase in both forest area and forest growth have resulted in a 

sustainable statewide resource of total forest biomass. Because most forest biomass is 

found in the boles of growing-stock trees on timberland, the management of private 

forest land strongly influences the future of not only the biomass resource but also 

carbon cycles and future wood availability. Given the potential increase in demand to 

manage forest biomass components for both carbon and biofuel uses, the monitoring 

of Indiana’s forest biomass is even more critical.

Privately owned forest land enrolled in the Classified Forest and Wildlands Program, 

the reversion of agricultural lands to forest, and conservation measures by federal, 

state, and local agencies contributed to the statewide increase in total biomass. 

As holders of the majority of Indiana’s forests, private forest landowners play an 

important role in sustaining biomass. The management of both public and private 

forest land has a strong effect on Indiana’s carbon sinks. If the State becomes involved 

in carbon trading, estimates of biomass and carbon sequestration by forests will 

become increasingly important.

Components of Annual Volume Change: Growth, 

Removals, and Mortality

Background

Well-tended forests supply a continuous flow of products without impairing longterm productivity. One way to judge the sustainability of a forest is to examine the 

components of annual change in inventory volume: growth, removals, and mortality. 

Net growth includes growth (accretion) on trees measured previously, ingrowth of 

trees over the 5-inch threshold for volume measurement, deductions for mortality 

due to natural causes, and volume of trees on lands reverting to forest. Removals 

include trees that are harvested and trees that are lost because the forest land was 
58 | FOREST FEATURES

developed for a nonforest use. Analysis of these individual components can help us 

better understand what is influencing net change in volume.

What we found 

During the last 60 years in Indiana, the growth of trees has greatly outpaced mortality 

and removals. The most recent inventory reveals that since 2008, the gross growth in 

the net volume of live trees totaled 354 million cubic feet annually. Annual mortality 

averages 118 million cubic feet, resulting in a net growth of 236 million cubic feet 

per year (Fig. 50). The removal of trees due to both harvesting and land-use change 

averaged 72 million cubic feet, leaving an annual surplus or net increase of 164 

million cubic feet on Indiana forest land. As a percentage of the current inventory, 

gross growth was 3.4 percent, mortality was 1.1 percent, net growth was 2.3 percent, 

and removals were 0.7 percent, resulting in a net change in total volume of 1.6 percent 

annually. Eighty-eight percent of net growth is on trees growing on land that was 

forested in both 2008 and 2013, and the remaining 12 percent is from trees on land 

that was previously nonforest and is now forest land. 

354 

-118 

236 

-72 

164 

-200 

0 

200 

400 

Gross

Growth 

Mortality Net

Growth 

Removals Net 

Change 

Volume (million ft3

)

Components of Change 

Figure 50.—Annual components of change in live volume on 

forest land, Indiana, 2008 to 2013. Error bars represent 1 standard 

error or a 68 percent confidence interval around the mean.

On land that was forest in both 2008 and 2013, accretion (growth on trees 5.0 inches 

d.b.h. and larger) accounted for 86 percent of the net growth; the remaining 14 

percent was ingrowth from trees growing into the 5-inch diameter class. Accretion 

was well distributed across diameter classes. Sixty-six percent of accretion was on 

trees that were at least 11 inches d.b.h. in the previous inventory (Fig. 51). Average 

annual net growth of sawtimber trees was highest in the Knobs Unit (197 million 

board feet), followed by the Northern (152 million board feet), Lower Wabash (144 

million board feet), and Upland Flats (79 million board feet) Units (Fig. 52).
 | 59

-10 

-5 

0 

5 

10 

15 

20 

25 

30 

6 8 

10 

12 14 

16 18 

20 

21-28.9 

29+ 

Net Growth (million ft3

)

2008 Diameter Class (inches d.b.h.) 

Figure 51.—Net growth volume on previously measured live trees 

(accretion) by previously measured diameter class on forest land, 

Indiana, 2008 to 2013.

0 100 200 300 400 500 600 

Knobs 

Lower Wabash 

Northern 

Upland Flats 

All Units 

197 

144 

152 

79 

572 

Net Growth (million board feet) 

FIA Unit 

Figure 52.—Average annual net growth of sawtimber trees on 

timberland, in million board feet (Doyle log rule), by inventory unit, 

Indiana, 2008 to 2013.

Statewide, 79 percent of the removals were due to the harvesting of trees on land that 

remained in forest and 21 percent were due to forest land being diverted to nonforest 

land. Sawtimber removals were highest in the Knobs and Lower Wabash Units (Fig. 53). 

On land that was forested in both 2008 and 2013, removals during the 2013 inventory 

were concentrated on the larger trees, with 87 percent of the removals, by volume, being 

sawtimber-size trees (Fig 54). 
60 | FOREST FEATURES

On Indiana forest land, the net growth-to-removals ratio (G/R) averaged 3.3:1 from 

2009 to 2013 (Fig. 55). Ratios were lower than the State average on the Lower Wabash 

and Knobs Units and higher on the Upland Flats and Northern Units (Fig. 56). 

G/R ratios varied considerably between species. Of the top 16 species by volume in 

Indiana, black walnut and red maple had the largest G/R ratios at 13.4:1 and 10.4:1, 

respectively (Fig. 57). Net growth exceeded removals for all major species. Yellowpoplar had the largest amount of growth followed by sugar maple and red maple. 

Yellow-poplar also accounted for the largest share of removals (16 percent), although 

growth still outpaced removals by a ratio of 2.9 to 1. The 2012 drought and tuliptree 

scale (Toumeyella liriodendri Gmelin) epidemic are two factors that contributed to the 

high rate of removals in yellow-poplar. Another factor impacting removals occurred 

in the southern Indiana Knobs Unit and Upland Flat Unit where foresters removed 

large yellow-poplar after realizing the trees would not make it to the next harvest 

because of drought intolerance and other site conditions.

0 50 100 150 200 250 

Knobs 

Lower Wabash 

Northern 

Upland Flats 

All Units 

105 

94 

32 

7 

238 

Removals (million board feet) 

FIA Unit 

Figure 53.—Average annual removals of growing-stock sawtimber 

trees on timberland, in million board feet (Doyle log rule), by 

inventory unit, Indiana, 2008 to 2013.
 | 61

0 

2 

4 

6 

8 

10 

12 

14 

6 8 10 12 14 16 18 20 22 24 26 28 30 

Removals Volume (million ft3

)

Previous Diameter Class (inches d.b.h.) 

Figure 54.—Average annual removals of live trees (5 inches 

d.b.h./d.r.c. and larger), by previously measured diameter class 

(2008) on forest land, Indiana, 2008 to 2013. Data excludes 

removals due to forest land being diverted to nonforest uses.

0 

50 

100 

150 

200 

250 

300 

350 

1966-1986 1986-1997 1999-2003 2004-2008 2009-2013 

Volume (million ft3

)

Years 

Net Growth 

Removal 

Figure 55.—Comparison of volume of net growth and removal of 

growing stock by inventory years, Indiana, 1966-2013. 
62 | FOREST FEATURES

0 10 20 30 40 50 60 70 80 

 Lower Wabash (1.8) 

Knobs (2.1) 

Upland Flats (7.2) 

Northern (5.3) 

Volume (million ft3

)

FIA Unit 

Removals 

Growth 

Figure 56.—Average annual growth and removals of live trees (at least 

5 inches d.b.h./d.r.c.) on forest land, by FIA unit, Indiana, 2008 to 2013. 

Growth-to-removals ratio (G/R) is listed in parentheses beside unit name. 

0 10 20 30 40 50 

Pignut hickory (6.9:1) 

Silver maple (1.6:1) 

Bitternut hickory (4.0:1) 

Shagbark hickory (3.8:1) 

Pin oak (5.8:1) 

Hackberry (9.3:1) 

Black oak (1.0:1) 

Black cherry (3.0:1) 

Northern red oak (2.0:1) 

Black walnut (13.4:1) 

White oak (2.4:1) 

American sycamore (5.2:1) 

White ash (2.2:1) 

Red maple (10.4:1) 

Sugar maple (2.8:1) 

Yellow-poplar (2.9:1) 

Volume (million ft3

)

Species 

Growth 

Removals 

Figure 57.—Average annual growth and removals of net volume on 

forest land by species, Indiana, 2008 to 2013. Growth-to-removals ratio 

(G/R) listed beside species name. Error bars represent 1 standard error 

or a 68 percent confidence interval around the mean.
 | 63

What this means

Today’s well-stocked forests are a product of growth consistently outpacing removals 

during the last half century and the surplus accumulating in the forest. Since 2008, net 

growth has been twice that of removals, with the net change amounting to an annual 

increase of 2.8 percent in inventory volume. This finding implies that the current level 

of removals is sustainable and that increases in volume will continue at the State level 

as well as in each of the FIA units. 

Comparing the G/R ratios of individual species to the average ratio for all species 

(3.3:1) reveals that the resource is being managed sustainably. The high G/R ratio 

for walnut indicates that this species will continue to be an important component in 

Indiana forests.

Mortality

Background 

The volume of trees that die from natural causes, such as insects, diseases, fire, 

wind, and suppression by other trees, is reported as mortality; harvested trees are 

not included in mortality estimates. Tree mortality is a natural process that occurs 

in a functioning ecosystem although dramatic increases in mortality because of 

catastrophic events can indicate problems with forest health.

What we found

In Indiana, average annual mortality was 118.3 million cubic feet between 2008 and 

2013, an annual rate of 1.1 percent of inventory volume. This is similar to rates in the 

neighboring states of Ohio (1.1 percent), Kentucky (1.0 percent), Illinois (1.6 percent), 

and Michigan (1.1 percent). By FIA unit, mortality to volume rates were highest in the 

Northern Unit (1.3 percent) followed by the Knobs Unit (1.2 percent). The Upland Flats 

and Lower Wabash Units both had mortality rates of 0.9 percent of unit volume (Fig. 58). 

Mortality rates were higher for smaller diameter trees than for larger ones, although 

rates do rise in the largest diameter trees (Fig. 59). The mortality rate in the 6-inch 

diameter class was 2.1 percent per year, which is nearly twice the average rate across 

all diameter classes; the 20-inch diameter class had the lowest mortality rate at 0.6 

percent. Trees less than 9.0 inches in diameter account for 17 percent of the total 

mortality, by volume, even though they represent only 11 percent of total volume.
64 | FOREST FEATURES

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 

Lower Wabash 

Knobs 

 Upland Flats 

Northern 

Mortality Rate (percent of current unit volume) 

FIA Unit 

Figure 58.—Average annual mortality rate as a percent of current live 

tree volume on forest land, by FIA unit, Indiana, 2008 to 2013.

0.0 

0.5 

1.0 

1.5 

2.0 

2.5 

6 8 10 12 14 16 18 20 22 23.0+ 

Mortality (percent of volume) 

Diameter Class (inches d.b.h.) 

Figure 59.—Average annual mortality rate as a percent of current live 

tree volume on forest land by diameter class, Indiana, 2008 to 2013.

Species with high annual mortality rates include American elm (4.2 percent), sassafras 

(1.9 percent), eastern cottonwood (1.9 percent), black oak (1.8 percent), white ash 

(1.4 percent), and green ash (1.2 percent) (Fig. 60). Yellow-poplar, the leading species 

in cubic-foot volume, had a lower mortality rate (0.7 percent) and ranked 15th when 

compared to the other 24 species.
 | 65

4.2 

1.9 

1.9 

1.8 

1.4 

1.2 

1.2 

1.2 

1.1 

1.1 

1.0 

1.0 

0.8 

0.7 

0.7 

0.7 

0.7 

0.6 

0.6 

0.5 

0.4 

0.3 

0.3 

0.3 

0.1 

0.0 1.0 2.0 3.0 4.0 5.0 

American elm 

Sassafras 

Eastern cottonwood 

Black oak 

White ash 

Green ash 

Black cherry 

Chestnut oak 

Pignut hickory 

American beech 

American basswood 

Northern red oak 

Silver maple 

Sugar maple 

Yellow-poplar 

Bitternut hickory 

Eastern redcedar 

Red maple 

White oak 

Sweetgum 

Pin oak 

Shagbark hickory 

American sycamore 

Black walnut 

Hackberry 

Mortality (percent of volume) 

Species 

State average for all species 

= 1.1% 

Figure 60.—Average annual mortality rate as a percent of current 

live tree volume for 25 major species, Indiana, 2008 to 2013.

What this means

The maturing of Indiana forests has resulted in crowded growing conditions. As trees 

compete for light and growing space, some fall behind their neighbors, lose vigor, and 

eventually succumb to insects and diseases. This is evident in the condition of trees 

in the small diameter classes. As discussed in the Tree Condition—Crown Position 

and Live Crown Ratio section, most trees less than 8.0 inches in diameter grow in 

the understory, and a fifth of the trees in the 6- and 8-inch diameter classes have 

live crowns less than 20 percent of their height, a sign of poor vigor in the smaller 

diameter classes. However, since the tree mortality rates in Indiana are about the same 

as the surrounding states, they can be considered normal.

Much of the mortality can be explained by stand dynamics or insects and diseases 

that target specific species. Elm and ash mortality is likely caused by Dutch elm 

disease and the emerald ash borer impacting these species. As the emerald ash 

borer infestation continues to spread, ash mortality will likely raise mortality rates 
66 | FOREST FEATURES

throughout the State. Black oak mortality is attributed to oak wilt, old age, drought, 

poor site conditions, and oak decline. Black oak trees are sensitive to stress, especially 

as they age. Trees weakened by environmental stresses such as drought or defoliation 

often readily succumb to secondary agents, including twolined chestnut borer 

(Agrilus bilineatus), hypoxylon canker (Hypoxylon mammatum), and shoestring root 

rot (Armillaria mellea). This periodic decline and death of oaks over widespread areas 

due to an interaction of environmental stresses and pests is referred to as oak decline 

(Wargo et al. 1983). Thus, as black oak increases in age and volume, an increase in 

sawtimber mortality and a decrease in sawtimber volume can be expected.

Mortality rates vary among tree species, and many species deviate substantially from 

the State average. Having a large diversity of species contributes to the resiliency of 

Indiana forests to the impacts of insects and diseases that attack individual species.
 | 67

Forest Indicators

Redbud tree flowers in bloom mingle with spring foliage at McCormick's Creek State Park. Photo by Indiana 

Department of Natural Resources, used with permission. 

 | 67
68 | FOREST INDICATORS

Urbanization and Fragmentation of Forest Land

Background

Fragmentation occurs naturally from disturbances such as wildfire, wind, and 

flooding, or as the result of human activities such as conversion to agriculture or 

urban development/sprawl. Human disturbance has a more severe impact on the 

remaining forest because it occurs more frequently and results in more permanent 

land-use changes than natural disturbance events. The expansion of urban lands 

that accompanies human population growth often results in the fragmentation 

and urbanization of remaining natural habitat (Wilcox and Murphy 1985). Forest 

fragmentation and habitat loss diminish biodiversity and are recognized as a major 

threat to animal populations worldwide (Honnay et al. 2005, Rosenberg et al. 1999). 

This is particularly true for species that require interior forest conditions for all or part 

of their life cycle (Donovan and Lamberson 2001), or are wide-ranging, slow-moving, 

or slow at reproducing (Charry 2007, Forman et al. 2003). Forest fragmentation can 

also affect forest ecosystem processes through changes in microclimate conditions, 

and it affects the ability of tree species to move in response to climate change (Iverson 

and Prasad 1998). Changes in the size of remaining forest patches, in their level of 

connectivity to other large patches, in the amount of general forest cover surrounding 

each patch, and in the amount of forest-nonforest edge all directly affect the amount 

and quality of interior forest and consequently the species and ecosystem functions that 

depend on these interior conditions. The same factors also affect the ease with which 

exotic, invasive, or generalist species can gain a foothold; the ability of wildlife species 

to move across the landscape; and the ability of the forest to protect the quality and 

quantity of surface and ground water supplies. 

Spatial landscape pattern metrics help quantify these different characteristics of 

fragmentation. In the last Indiana inventory (Woodall et al. 2011), the amount of 

edge vs. core forest was examined with respect to the most widely used thresholds for 

interpreting likely impact. The results highlighted the large proportion of Indiana forest 

in edge conditions (58 percent) and the range of landscape conditions between Indiana’s 

more forested southern half and the dominantly agricultural northern half. 

Metric values are sensitive to the resolution of the land cover data source used (Moody 

and Woodcock 1995), similar to the way that animal species see the landscape very 

differently depending on the scale at which they operate—e.g., the same patch that 

supplies interior forest conditions for one species is viewed as an unsuitable fragment 

by another species with higher quality or larger area requirements. Because important 

forest ecosystem processes operate at different scales, current levels of fragmentation are 

examined at two scales by adapting a spatial integrity index (SII) developed by Kapos 

et al. (2000) for the Global Forest Resources Assessment (FRA). The SII integrates three 
 | 69

facets of fragmentation that affect some aspect of forest ecosystem functioning—patch 

size, local forest density, and patch connectivity to core forest areas—to create a single 

resulting metric for comparison (Table 3). Since even acceptably low misclassification 

rates in the source land cover data can be magnified into substantial errors in metric 

values (Langford et al. 2006, Shao and Wu 2008), spatial integrity is calculated at two 

scales corresponding to two reliable and widely available source datasets, the 30 m scale 

of the 2011 National Land Cover Dataset (NLCD) (Jin et al. 2013) and the 250 m scale 

of the 2009 FIA forest cover dataset (Wilson et al. 2012). Both scales fall within the 10 

to 1,000 km2

 scale at which pattern process linkages are often of greatest management 

interest (Forman and Godron 1986). 

Scale

Definition of core 250 m 30 m

Patch size >1,544 acres >22 acres

Local forest density 90% 90%

Neighborhood radius 0.78 mile 0.09 mile

Definition of unconnected fragment 250 m 30 m

Patch size <30 acres <2.5 acres

Local forest density 10% 10%

Neighborhood radius 0.78 mile 0.09 miles

Distance to core >4.2 miles >0.5 miles

Table 3.—Spatial Integrity Index (SII) parameters used in calculations at each scale

In the SII calculation, core forest is defined by patch size and local forest density 

within a defined local neighborhood area. An unconnected forest fragment is defined 

by its patch size, local forest density, and distance to a core forest area, and the spatial 

integrity of all other forest lands are scaled between these two ends. Table 3 identifies 

the thresholds used to define both core forest and unconnected fragments at the 250 

m and 30 m scales. These two scales capture a relatively broad range of definitions 

for core forest and spatial integrity that should encompass the scales appropriate for 

understanding impacts on a wide range of wildlife species and ecosystem processes 

affected by forest fragmentation.

The population of Indiana increased by 6.6 percent between 2000 and 2010, to 6.5 

million people. During that same time period, the number of housing units increased 

by 10.7 percent (U.S. Census Bureau 2010). Stated another way, between 2000 and 

2010 housing units increased at a pace 1.6 times the rate of increase in population, a 

trend not unique to Indiana. In recent decades this housing growth has occurred not 

only in increasing suburban rings around urban areas but also in rural areas. Lepczyk 

et al. (2007), Theobald (2005), and Hammer et al. (2004) observed that areas currently 

facing rapid increases in housing density and areas predicted to increase in the future 

are amenity-rich rural areas around lakes and other forest recreation areas. The 35 
70 | FOREST INDICATORS

percent increase in the number of reported second homes from 2000 to 2010 could 

be a partial reflection of this trend in Indiana (U.S. Census Bureau 2010). This can put 

additional pressure on forested areas even above the general increases in population 

density and housing density. 

What SII identifies as core does not represent completely intact forest conditions 

because it is calculated from forest canopy and does not consider underlying house 

densities or proximity to roads. Using the definition of wildland-urban interface 

(WUI) intermix from Radeloff et al. (2005) (greater than 15.5 houses per square mile 

[6 houses per square km]), the amount of forest, and particularly core or intact forest 

land, that coincided with these areas was identified. The WUI is described as the 

zone where human development meets or intermingles with undeveloped wildland 

vegetation. It is associated with a variety of human-environment conflicts. Radeloff 

et al. (2005) have defined this area in terms of the density of houses (WUI “intermix” 

areas), the proximity to developed areas (WUI “interface” areas), and percentage 

of vegetation coverage. WUI intermix areas intersected with forest land in the 2011 

NLCD (Jin et al. 2013) were used to examine changes in the amount of forest land cooccurring with WUI house densities. 

Roads are another important impact of urbanization that affect forest lands but 

are not completely captured by either of the previous two indices. In Indiana as a 

whole, 43 percent of the forest land was within 650 feet of a road of some sort, and 

75 percent was within 1,310 feet when calculated using NLCD 2006 forest (Fry et al. 

2011) and U.S. Census Bureau (2000) roads. Roads have a variety of effects: direct 

hydrological, chemical, and sediment effects; serving as vectors for invasive species; 

facilitating human access and use; increasing habitat fragmentation; and wildlife 

mortality. Actual impacts will vary depending on road width, use, construction, level 

of maintenance, and hydrologic and wildlife accommodations (e.g., Charry 2007, 

Forman et al. 2003). In general, when greater than 60 percent of the total land area 

in a region is within 1310 feet of a road, cumulative ecological impacts from roads 

should be an important consideration (Riitters and Wickham 2003). 

What we found

Considering SII classes at the 250 m scale, 21 percent of the forest land in Indiana is 

core forest, 24 percent has high spatial integrity, 13 percent has medium integrity, 2 

percent has low integrity, and 41 percent of the forest is in unconnected fragments. 

At the 30 m scale, with 22 acres or greater considered core forest, 45 percent of the 

forest land in Indiana is core forest, 21 percent has high spatial integrity, 9 percent has 

medium or low integrity, and 24 percent of the forest is in unconnected fragments. 

Table 4 contains a breakdown of SII values by FIA unit for both scales. Forest 
 | 71

Forest by 30 m spatial integrity class Forest by 250 m spatial integrity class

Unit

Forest 

fragment

Low 

SII

Medium 

SII

High 

SII

Core 

forest

Forest 

fragment

Low 

SII

Medium 

SII

High 

SII

Core 

forest

--------------------- percent ------------------- --------------------- percent -------------------

Lower Wabash 18 1 11 23 46 51 2 11 18 18

Knobs 9 1 7 22 61 19 2 13 33 33

Upland Flats 9 1 9 25 56 27 5 29 27 11

Northern 59 1 8 16 16 91 0 2 4 2

State 24 1 8 21 45 41 2 13 24 21

State after 

incorporating 

WUI areas

24 2 9 34 31 41 4 13 27 15

Table 4.—Proportion of forest land for 30 m and 250 m spatial integrity index (SII) classes by FIA unit, Indiana

connectivity is highest in the Knobs Unit and lowest in the Northern Unit. Large areas 

of relatively continuous forest clearly stand out at the 250 m scale (Fig. 61). At the 30 

m scale, the lower threshold of 22 acres for defining core forest means that more forest 

patches are considered core. Figure 62 compares the SII classes between the two scales 

for an area southwest of Indianapolis. It is important to note that the forest landscape 

data used here are depicting tree cover only and may not incorporate the presence of 

local development associated with or underlying this tree cover. 

Forest land with a sufficient underlying housing density to qualify as WUI areas has 

been steadily increasing. In 1990, approximately 20 percent of the forest land was 

in low and medium density WUI. In 2000 this increased to 24 percent of the forest 

land, and in 2010 it was 27 percent of the forest land in Indiana. The distribution of 

forested WUI in Indiana is depicted in Figure 63. Substantial impact to forest land 

is visible southwest of Indianapolis, in the outskirts of Cincinnati, OH, and near the 

southern border of Indiana. These underlying house densities are poorly captured by 

the tree canopy cover data used in the calculation of spatial integrity above. When SII 

results at the 250 m scale are integrated with the WUI classes, 6 percent of Indiana 

forest land moves from core forest to lower spatial integrity classes, decreasing the 

proportion of forest land in the core class from 21 percent to 15 percent. At the 

30 m scale, 14 percent of Indiana forest land moves from core forest to a lower 

spatial integrity class, decreasing the proportion from 45 percent to 31 percent. This 

represents a substantial impact on core forest land from underlying or nearby house 

densities. The effects tend to concentrate around the outskirts of major cities and 

amenity-rich areas, and thus may be locally quite noticeable. Figure 64 depicts the 

changes in SII that occur when WUI status is incorporated, in the area southwest of 

Indianapolis. 
72 | FOREST INDICATORS

A B

Forested Area

Unconnected

Low integrity

Med integrity

High integrity

Core

Nonforest

Forested Area

Unconnected

Low integrity

Core

Nonforest

Medium integrity

High integrity

Figure 61.—Forest land by spatial integrity index classes at the 

250 m scale, Indiana, 2006.

Forested Area

Unconnected

Low integrity

Med integrity

High integrity

Core

Nonforest

Forested Area

Unconnected

Low integrity

Med integrity

High Integrity

Core

Nonforest

Figure 62.—Forest land by spatial integrity index at the 250 m scale (A) and 30 m scale (B) in an area southwest of 

Indianapolis, Indiana, 2006.
 | 73

Forested Area

Non-WUI

WUI

Nonforest

Figure 63.—Forest land by wildland urban interface (WUI status), 

Indiana, 2006.

Forested Area

Non-WUI

WUI

Nonforest

Figure 64.—Forest land by spatial integrity index (SII) at the 30 m scale, with (A) and without (B) incorporating WUI 

status into SII, in an area southwest of Indianapolis, Indiana, 2006.

Forested Area

Unconnected

Low integrity

Med integrity

High Integrity

Core

Nonforest

A B

Forested Area

Unconnected

Low integrity

Med integrity

High integrity

Core

Nonforest
74 | FOREST INDICATORS

Roads remain pervasive in the landscape, existing even in areas that appear to be 

continuous forest land from the air. In 2000, the proportion of forest area in each 

unit that was within 650 of a road was 42 percent in the Knobs, 43 percent in Upland 

Flats, 43 percent in Northern, and 47 percent in Lower Wabash (U.S. Census Bureau 

2000) (Table 5 and Fig. 65). Much of this area coincides with areas of current or 

future housing development. It is also worth noting that the roads included in the U.S. 

Census Bureau (2000) Tiger data may not include minor roads that are not associated 

with housing development, and that including these minor roads actually doubles 

road densities in areas like northern Wisconsin (Hawbaker and Radeloff, 2004).

FIA unit

Forest of total land in 

unita

Forest land in wildland 

urban intermixb

Forest land < 650 feet 

from a roadc

----------------------------------------- percent ---------------------------------------

Lower Wabash 30 22 47

Knobs 52 35 42

Upland flats 48 33 43

Northern 11 14 43

State Total 24 27 43

a

 Percent forest estimate based on NLCD 2011 (Jin et al. 2013). Values are generally higher than estimates from FIA 

 plot data.

b Approximating the forest land potentially affected by underlying or nearby development (2010 Census Data).

c

 Approximating the forest land potentially affected by roads (U.S. Census Bureau 2000, TIGER/Line).

Table 5.—Distribution of forest land based on several urbanization and fragmentation factors, expressed as a percent 

of the forest land in each FIA unit, Indiana
 | 75

Foreste

< 65

650 

>13

Figure 65.—Forest land by distance from the nearest road, Indiana, 2000.

Forested Area

<650 feet

650 to 1,310 feet

>1,310 feet
76 | FOREST INDICATORS

What this means

At the 250 m and 30 m scales, only 21 to 45 percent of the forest land in Indiana meets 

the definition of core forest statewide, and between 24 and 41 percent of the forest 

land is in unconnected fragments. Incorporating WUI areas into the calculation has a 

substantial effect on what is considered core forest, reducing core forest by almost a third 

at the 30 m scale. The effect is even greater in several local areas. Bringing roads into the 

calculation, even at the levels available in the 2000 Census TIGER dataset (U.S. Census 

Bureau 2000), reduces the integrity of some areas still further.

Forest fragmentation is recognized as a major threat to wildlife populations, particularly 

for species that require interior forest conditions for all or part of their life cycle or who 

are wide-ranging or slow-moving, because it increases edge conditions, which can 

change micro-climate conditions and ecosystem processes, and limits the ability of plants 

and animals to move in response to climate change (e.g., Forman et al. 2003, Honnay et 

al. 2005, Iverson and Prasad 1998).

Urbanization increases the proximity of people, development, and other anthropogenic 

pressures to natural habitats. Both urbanization and forest fragmentation change the 

way in which humans use forest land, frequently decreasing the likelihood that it will be 

managed for forest products and potentially increasing its use for outdoor recreation, 

although urbanization has also been observed to increase the incidence of posting no 

trespassing signs on forested land, which decreases outdoor recreation opportunities 

and alters local cultural use of forest land (Butler 2008, Kline et al. 2004, Wear et al. 

1999). Continuing fragmentation, parcelization, and urbanization can be barriers to 

stewardship if they result in forest tracts that are too small or too isolated for effective 

management (Shifley and Moser 2016).

Invasive species and introduced pests are also a concern, as is the ability of forest 

systems to adapt to changes in season, temperatures, rainfall patterns, and relative 

phenological shifts associated with climate change. An intact functioning forest also is 

critical in protecting both the quantity and quality of surface and groundwater resources 

(McMahon and Cuffney 2000, Riva-Murray et al. 2010). 

Fragmentation and urbanization are changing how Indiana forests function and affect 

forest sustainability. Fragmentation diminishes the benefits and services forests provide 

and makes forest management more difficult. As Indiana’s population continues to 

sprawl into rural areas, fragmentation of forest land is a growing concern to land 

managers. Factors that increase fragmentation, such as development incursions into core 

and high integrity forest areas, should become the focus of conservation and planning 

activities. In addition, the characteristics and maintenance of roads and development can 

play a role in their actual impact on the resilience of forest land and its ability to continue 

to supply the forest products and ecosystem services we expect and need.
 | 77

Down Woody Materials

Background 

Down woody materials, in the various forms of fallen trees and shed branches, fulfill a 

critical ecological niche in forests of Indiana. Down woody materials provide valuable 

wildlife habitat, stand structural diversity, a store of carbon/biomass, and contribute 

toward forest fire hazards via surface woody fuels. 

What we found 

The total carbon stored in down woody materials (fine and coarse woody debris 

and residue piles) on Indiana forest land exceeded 17 million tons. Downed woody 

debris carbon was normally distributed by stand-age class (Fig. 66) with moderately 

aged stands having the highest total carbon (~6 million tons). The downed dead 

wood biomass within Indiana forests is dominated by coarse woody debris (Fig. 67) 

at approximately 22 million tons with fine woody debris representing more than 

a third of statewide totals. The total volume of coarse woody debris was highest in 

the private ownership category at approximately 2 billion cubic feet (Fig. 68). State 

and local forests had the second largest totals of coarse woody debris volume (~279 

million cubic feet) compared to private ownerships. Given the relatively sparse sample 

intensity of Phase 3 down dead woody materials plots across Indiana, no dead wood 

piles were sampled, although there is large sampling uncertainty associated with such 

an inventory. 

0

1

2

3

4

5

6

7

8

0-20 21-40 41-60 61-80 81-100 100+

Total Carbon (million tons)

Stand Age (years)

Figure 66.—Total carbon stored in down woody materials (fine 

and coarse woody debris and residue piles combined) by stand 

age, Indiana, 2013. Error bars represent 1 standard error or a 68 

percent confidence interval around the mean.
78 | FOREST INDICATORS

Fine woody 

debris

37%

Coarse woody

debris

63%

Piles

0%

Figure 67.—Percentage of downed dead wood biomass by 

component, Indiana, 2013. 

0

500

1,000

1,500

2,000

2,500

National 

Forest

Other 

Federal

State and 

Local

Private

Volume (million ft3

)

Ownership Group

Figure 68.—Total volume of coarse woody debris on forest land 

by ownership group, Indiana, 2006 to 2010. Error bars represent 1 

standard error or a 68 percent confidence interval around the mean.

What this means 

Given the relatively moist temperate forests across Indiana, only in times of drought 

would the biomass with down woody materials be considered a fire hazard. Although 

the carbon stocks of down woody materials are relatively small compared to those 

of soils and standing live biomass across Indiana, down woody materials are still a 

critical component of the carbon cycle as a transitory stage between live biomass and 

other detrital pools such as the litter. Beyond transition of dead wood carbon to other 

pools, if future temperature and precipitation patterns change, there is a potential for 

a reduction in these stocks due to increased rates of decay (Russell et al. 2014a, 2014b). 

The loss of dead wood carbon stocks could indicate the reduction of other pools in 

the future. Compared to southeastern states where there is more pervasive industrial 

management of forests (Woodall et al. 2013), no dead wood piles were sampled in this 

first down woody materials inventory of Indiana forests. Given that the vast majority 
 | 79

of coarse woody debris volume was estimated to be in private ownership, it is the 

management of Indiana’s private forests that may affect the future of down woody 

material contributions to statewide forest carbon stocks and wildlife habitat (i.e., 

stand structure). Overall, because estimates of fuel loadings are not exceedingly high 

across Indiana, the numerous ecosystem services provided by down woody materials 

will likely outweigh possible fire dangers.

Soils

Background

Rich soils are the foundation of productive forest land. Inventory and assessment of 

the forest soil resource provides critical baseline information on forest health and 

productivity, especially in the face of continued natural and human disturbance. 

The forest soils of Indiana were sampled comprehensively from 2000 through 2005. 

Soils change very slowly, and a remeasurement of the soil was resumed in 2012. 

Additionally, the soils data require laboratory analyses to provide the complete suite 

of information (e.g., soil carbon content and nutrient concentrations). Unfortunately, 

these data are not available for analysis in this report. However, several analyses 

completed at the regional level are relevant to discussions of land use and forestry 

interactions with soil resources.

What we found

Peatland soils are found in the northern part of Indiana (Fig. 69). Most of the areas have 

been converted to nonforest, but some peatland soils continue to support forest cover. 

Their per-unit-area carbon stocks are exceptionally high; peatlands cover 3 percent of 

the world’s surface area, but they store 30 percent of the globe’s soil carbon. They are 

also sensitive to climate change, and warming temperatures are expected to increase 

decomposition rates and release large amounts of stored carbon to the atmosphere. The 

Forest Service examined several methods of estimating peatland carbon and found that 

peat thickness is the best predictor of total carbon storage. 

Several projects are integrating tree measurements with soil chemistry and other factors 

to evaluate the impacts of atmospheric deposition of nutrients on tree growth and 

mortality. Sugar maple, one of the trees commonly evaluated, is found in Indiana. Tree 

basal area and geologic factors are powerful predictors of sugar maple mortality, along 

with soil chemical attributes like the ratio of magnesium to manganese. 
80 | FOREST INDICATORS

Figure 69.—Distribution of forested and nonforested peatlands, Indiana, 2013. 

Peatlands

Forested

Nonforested

Source: Soils data (U.S. General Soil Map) 

provided by the USDA Natural Resources 

Conservation Service and available online at 

http://websoilsurvey.nrcs.usda.gov/.

Several million dollars are being invested to facilitate Great Lakes restoration under the 

coordination of the U.S. Environmental Protection Agency. To prioritize investments, 

the Forest Service conducted a thorough analysis to identify which watersheds were the 

greatest contributors of sediment and phosphorus runoff into Lake Michigan. Land use 

characteristics like forest cover, forest harvest, agriculture, and watershed storage (the 

abundance of lakes and wetlands) were useful predictors of stream water quality at river 

mouths (Figs. 70 and 71). 
 | 81

Figure 70.—Predictions of sediment delivery from gauged and 

ungauged watersheds draining into southern Lake Michigan. Adapted 

from Seilheimer et al. (2013).

Figure 71.—Predictions of phosphorus delivery from gauged and 

ungauged watersheds draining into southern Lake Michigan. Adapted 

from Seilheimer et al. (2013).

WISCONSIN

Lake Michigan MICHIGAN

ILLINOIS

INDIANA

WISCONSIN

Lake Michigan MICHIGAN

ILLINOIS

INDIANA

Risk in Ungauged 

Basins

High

Moderate

Low

Risk in Ungauged 

Basins

High

Moderate

Low

Gauged Basins 

(mg/L)

>0.075

0.050-0.075

<0.050

Gauged Basins 

(NTU)

>25

10-24

0-9

Area of Interest

Area of Interest

Sources: Watersheds processed with a water quality model 

developed by Seilheimer et al. (2013). Grey basins had insufficient 

data to model.

Sources: Watersheds processed with a water quality model 

developed by Seilheimer et al. (2013). Grey basins had insufficient 

data to model.
82 | FOREST INDICATORS

What this means

The Forest Service and its partners are evaluating changes to soil inventory protocols 

which should provide more precise estimates of peatland soil carbon. Integrating 

studies like the SPRUCE project (http://mnspruce.ornl.gov/) with improved 

inventories of peatlands will improve our understanding and management of these 

important soil carbon stocks.

Sugar maple is the second most common tree species found in Indiana. Indiana’s 

location puts it in the upwind side of increased deposition of commercial and 

residential emissions of nitrogen and sulfur. Atmospheric deposition is linked to 

altered soil chemistry and sugar maple mortality, particularly when they are found in 

the oak/hickory forest-type group. 

Forest inventory data, when combined with other observations of land use and its 

characteristics, can help land managers understand patterns of water quality across the 

broader landscape. When predictors offer significant explanatory power, these are clues 

to the types of management and policy actions that can be useful in restoration activities.

Tree Condition—Crown Position and Live Crown 

Ratio 

Background

The crown position of a tree indicates how well it is competing for light with 

neighboring trees. A tree crown in an intermediate or overtopped position is below 

the general level of the canopy and is shaded by its dominant and codominant 

neighbors. Intermediate and overtopped trees generally have slower growth and 

higher mortality rates than trees in more dominant positions. The live crown ratio 

defined as the percentage of a tree’s height in live crown, is an indication of its vigor. 

Live crown ratios of less than 20 percent are typically a sign of poor vigor. In the 

understory, trees with low live crown ratios have fallen behind in their struggle to 

compete with the surrounding trees for light and space and are unlikely to recover or 

grow into an overstory position unless their crowns are released from the competition 

with their neighbors by timber harvesting or another disturbance.

What we found 

In Indiana, most trees in the 2-, 4-, 6- and 8-inch diameter classes are in an 

overtopped or intermediate crown position. Ninety-six percent of 2-inch trees and 80 
 | 83

percent of 6-inch trees are considered suppressed (Fig. 72). Conversely, 92 percent of 

trees with diameters 14 inches or larger are dominant, codominant, or open grown. 

Fourteen percent of all trees in the 10-inch diameter class and below have live crown 

ratios of less than 20 percent. For the 6-inch class, 12 percent have live crown ratios 

below 20 percent and 40 percent have crown ratios below 30 percent (Fig. 73).

0

20

40

60

80

100

2 4 6 8 10 12 14 16 18 20 22 24 26 28 30

Percent of Trees in Class

Diameter Class (inches d.b.h.)

Overtopped

Intermediate

Codominant

Dominant

Open grown

Figure 72.—Distribution of trees on forest land, by diameter 

class and crown position, Indiana, 2013.

0 

10 

20 

30 

40 

50 

2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 

Trees in Class (percent) 

Diameter Class (inches d.b.h.) 

<20 percent 

<30 percent 

Figure 73.—Distribution of trees on forest land with a live crown 

ratio <20 percent or <30 percent, by diameter, Indiana, 2013.

What this means

Shaded conditions created by overstory trees are stressing a large portion of trees less 

than 10 inches in diameter. This finding is consistent with the maturing of Indiana 

forests and is the likely cause of the observed smaller increases in the number of trees in 

diameter classes less than 12 inches when compared to changes in larger trees. Shaded 

conditions favor the growth of shade tolerant species such as sugar maple over that of 

less shade tolerant species such as black cherry, yellow-poplar, oaks, and hickories.
84 | FOREST INDICATORS

Crown Health

Background

The crown condition of trees is influenced by various biotic and abiotic stressors. 

Abiotic stressors include drought, flooding, cold temperatures or freeze injury, 

nutrient deficiencies, soil physical properties that affect soil moisture and aeration, 

and toxic pollutants. Biotic stressors include native or introduced insects, diseases, 

invasive plant species, and animals. Invasions by exotic diseases and insects are one 

of the most important threats to the productivity and stability of forest ecosystems 

around the world (Liebhold et al.1995, Pimentel et al. 2000, Vitousek et al. 1996). 

Over the last century, Indiana forests have suffered the effects of native insect pests 

including forest tent caterpillar (Malacosoma disstria) and the looper complex 

(half winged geometer [Phigalia titea] and linden looper [Erannis tiliaria]), and 

well-known exotic and invasive agents such as Dutch elm disease and oak wilt 

(Ceratocystis fagacearum). More recent invasions include the emerald ash borer. 

Tree-level crown dieback is collected on Phase 2-plus (P2+) plots. Crown dieback, 

defined as recent mortality of branches with fine twigs, reflects the severity of recent 

stresses on a tree. A crown is labeled as “poor” if crown dieback is greater than 20 

percent. This threshold is based on findings by Steinman (2000) that associated 

crown ratings with tree mortality. Crown dieback has been shown to be the best 

crown variable to use for predicting tree survival (Morin et al. 2012).

What we found

The incidence of poor crown condition is low across Indiana with no discernable 

spatial pattern (Fig. 74). White ash and black oak are the only species in which 10 

percent or more of the live basal area contains poor crowns (Table 6). Mean dieback 

ranges from 5 percent for red maple to approximately 13 percent for white ash 

(Table 7).

An analysis of trees that were remeasured from the previous inventory revealed 

that the proportion of the trees that die increases with increasing crown dieback in 

the previous inventory (Fig. 75). More than 65 percent of trees with crown dieback 

greater than 20 percent during the 2008 inventory were dead when visited again 

during the 2013 inventory.
 | 85

0.0

0 - 5

>5

Forest

Nonforest

Water

Percent of Live Basal

Area with Poor Crowns

Figure 74.—Percentage of live basal area for all species on FIA plots with 

poor crowns, Indiana, 2013. Depicted plot locations are approximate.

Percent of Live Basal 

Area with Poor Crowns

0

0-5

>5

Forest

Nonforest

Water

 Basal area with poor crowns

Species 2008 2013

--------------------------------- percent ---------------------------

White ash 15.6 10.2

Black oak 0 10

Black cherry 0.5 6.9

Yellow-poplar 3.7 5.9

Red maple 0 0

Sugar maple 0.5 0

Shagbark hickory 2.7 0

American sycamore 9 0

White oak 0 0

Northern red oak 4.1 0

Table 6.—Percentage of live basal area with poor crowns for the 10 most common tree species by net volume, Indiana, 

2008 and 2013
86 | FOREST INDICATORS

Trees Mean SE Minimum Median Maximum

Species number --------------------------------------percent-----------------------------------

White ash 92 12.8 2.3 5 5 99

Northern red oak 32 11.8 4.1 5 5 99

Yellow-poplar 98 10.7 2.3 0 5 99

Shagbark hickory 23 9.3 4.1 5 5 99

Black cherry 81 6.7 1.2 0 5 99

American sycamore 22 6.4 1.9 0 5 45

Black oak 27 5.7 0.6 0 5 15

White oak 39 5.4 0.3 0 5 15

Sugar maple 141 5.1 0.4 0 5 50

Red maple 58 5 0.3 0 5 10

Table 7.—Mean crown dieback and other statistics for live trees (>5 inches d.b.h.) on forest land by species, Indiana, 2013

0 

10 

20 

30 

40 

50 

60 

70 

80 

90 

100 

0 1-10 11-20 >20 

Frequency (percent) 

Crown Dieback (percent) 

Cut 

Mortality 

Survivor 

Figure 75.—Crown dieback distribution by tree survivorship for 

remeasured trees, Indiana, 2008 to 2013.

What this means

The most important tree species in the forests of Indiana are generally in good health, 

but substantial dieback was observed in white ash and black oak. Emerald ash borer 

is the likely agent causing decline in the crown health of white ash (see subsequent 

section), and the health of black oak may be related to oak decline and oak wilt. 

Additionally, maple is at risk due to the recent invasions (and eradication) by Asian 

longhorned beetle (Anoplophora glabripennis) in neighboring Illinois, and walnut 

is at risk because of the recent finding of thousand cankers disease in Ohio (see 

subsequent sections). 
 | 87

Tree Damage

Background

Tree damage is assessed for trees at least 5.0 inches in diameter. Up to three damages can 

be recorded. If more than three damage agents are observed, decisions about which three 

are recorded are based on the relative abundance of the damaging agents and potential 

severity to the health of the tree. In general, agents that affect the roots or bole tend to 

be most threatening because they have the capacity to affect the entire tree. Damage to 

peripheral parts of the tree may be temporary because leaves, shoots, and reproductive 

structures may be replaced. The types of damage that are recorded include general insects, 

bark beetles, defoliators, chewing insects, sucking insects, boring insects, general diseases, 

root/butt rot diseases, cankers (non-rust), stem decays, parasitic/epiphytic plants, decline 

complexes/dieback/wilts, stem rusts, broom rusts, fire, wild animals (from birds to large 

mammals), domestic animals, abiotic factors (e.g., broken branches from wind, snow, 

or ice), competition (suppression of overtopped shade intolerant tree species), human 

activities (including poor pruning, vandalism, and logging injury), harvest, as well as 

unknown damage agents.

What we found

Damage was recorded on approximately 26 percent of the sampled trees in Indiana 

(Table 8), but the frequency of damage varied among species. Decay was the most 

frequently observed damage on all species (22 percent of trees) but ranged from 13 

percent on yellow-poplar up to 27 percent on sugar maple. Other damages were split 

nearly evenly between insect damage, decay, other animal, weather, and logging/human 

(3 percent or less for each). Notably, insect damage was recorded on 3 percent of white 

ash trees and 90 percent of those damages were attributed to bole borers.

Damage type

None Animal Cankers Decay

Insect 

damage

Logging/

human Other Weather

All 74 1 0 22 1 2 2 3

American sycamore 75 1 0 22 0 1 2 2

Black cherry 71 1 1 25 0 1 3 4

Black oak 81 0 0 15 1 2 2 2

Northern red oak 82 1 0 15 0 2 1 1

Red maple 72 1 0 25 0 2 2 4

Shagbark hickory 85 1 0 13 0 2 1 1

Sugar maple 69 1 0 27 0 3 2 3

White ash 73 2 0 20 3 2 3 2

White oak 85 1 0 12 0 2 1 1

Yellow-poplar 83 1 0 13 0 1 2 3

Note that columns do not sum to 100 because multiple damages can be recorded on each tree.

Table 8.—Percentage of trees with damage by species, Indiana, 2013
88 | FOREST INDICATORS

What this means

As in most eastern forests, decay is the most commonly observed damage in Indiana 

forests. This is not unusual given that the majority of the forests are composed of 

mature trees. The incidence of bole borer damage on white ash trees was observed 

most frequently in counties in the Northern Unit and is due to emerald ash borer 

infestations (see subsequent emerald ash borer section).

Forest Invaders: Invasive Plants

Background

Invasive plant species (IPS) are both native and nonnative species that can cause 

negative ecological effects. These species can quickly invade forests and change light, 

nutrient, and water availability. IPS can form dense monocultures which not only 

reduce regeneration but also impact wildlife quality by altering forest structure and 

forage availability. While there are beneficial uses for some invasive plants, including 

culinary and medicinal uses and soil contaminant extraction (e.g., reed canary grass) 

(Kurtz 2013), the negative effects are worrisome. Each year inspection, management, 

and mitigation of IPS costs billions of dollars.

Invasive species can also impact agriculture systems. Common barberry is an alternate 

host for wheat stem rust which can cause the complete loss of some grain fields (Kurtz 

2013). Common buckthorn is also a troublesome invader as it is one of the alternate 

hosts for the soybean aphid (Aphis glycines). To aid in monitoring these species, 

FIA assesses the presence of 43 IPS and one undifferentiated genus (nonnative bush 

honeysuckles). However, since nonnative bush honeysuckles are sometimes coded by 

field crews at the genus level and other times at the species level, this section discusses 

the monitoring of 40 IPS (39 species plus nonnative bush honeysuckles, hereafter 

referred to as “invasive species,” “invasive plants,” “invasives,” or “IPS”) and focuses on 

the 321 P2 invasive plots that were measured in Indiana from 2009-2013, highlighting 

changes from the previous inventory.

What we found

Of the 40 invasive species monitored by FIA (Table 9), 25 were observed on plots 

measured between 2009 and 2013 (Table 10). Multiflora rose was the most commonly 

observed IPS and was found on 239 plots (74.5 percent of P2 Invasive plots) that were 

distributed throughout the State (Fig. 76). Nonnative bush honeysuckle (120 plots) and 
 | 89

Tree Species Vine Species

Black locust (Robinia pseudoacacia) English ivy (Hedera helix)

Chinaberry (Melia azedarach) Japanese honeysuckle (Lonicera japonica)

Norway maple (Acer platanoides) Oriental bittersweet (Celastrus orbiculatus)

Princesstree (Paulownia tomentosa) 

Punktree (Melaleuca quinquenervia) Herbaceous Species

Russian olive (Elaeagnus angustifolia) Black swallow-wort (Cynanchum louiseae)

Saltcedar (Tamarix ramosissima) Bull thistle (Cirsium vulgare)

Siberian elm (Ulmus pumila) Canada thistle (Cirsium arvense)

Silktree (Albizia julibrissin) Creeping jenny (Lysimachia nummularia)

Tallow tree (Triadica sebifera) Dames rocket (Hesperis matronalis)

Tree of heaven (Ailanthus altissima) European swallow-wort (Cynanchum rossicum)

Garlic mustard (Alliaria petiolata)

Shrub Species Giant knotweed (Polygonum sachalinense)

Autumn olive (Elaeagnus umbellata) Japanese knotweed (Polygonum cuspidatum)

Common barberry (Berberis vulgaris) Leafy spurge (Euphorbia esula)

Common buckthorn (Rhamnus cathartica) Bohemian knotweed (Polygonum xbohemicum)

European cranberrybush (Viburnum opulus) Purple loosestrife (Lythrum salicaria)

European privet (Ligustrum vulgare) Spotted knapweed (Centaurea stoebe ssp. micranthos)

Glossy buckthorn (Frangula alnus)

Japanese barberry (Berberis thunbergii) Grass Species

Japanese meadowsweet (Spiraea japonica) Common reed (Phragmites australis)

Multiflora rose (Rosa multiflora) Nepalese browntop (Microstegium vimineum)

Nonnative bush honeysuckles (Lonicera spp.) Reed canarygrass (Phalaris arundinacea)

Table 9.—List of 39 invasive plant species and one undifferentiated genera monitored by the Northern Research Station 

on FIA P2 Invasive plots, 2007 to present

Name Observances Percentage of plots 

Multiflora rose 239 74.5

Nonnative bush honeysuckles 120 37.4

Japanese honeysuckle 103 32.1

Nepalese browntop (Japanese stiltgrass) 95 29.6

Garlic mustard 63 19.6

Autumn olive 55 17.1

Black locust 38 11.8

Reed canarygrass 32 10

European privet 22 6.9

Creeping jenny 20 6.2

Oriental bittersweet 20 6.2

Canada thistle 12 3.7

Dames rocket 12 3.7

Bull thistle 10 3.1

Tree of heaven 7 2.2

Japanese barberry 6 1.9

Common barberry 5 1.6

Common buckthorn 3 0.9

Glossy buckthorn 3 0.9

Japanese meadowsweet 2 0.6

European cranberrybush 2 0.6

Siberian elm 1 0.3

Japanese knotweed 1 0.3

Russian olive 1 0.3

English ivy 1 0.3

Table 10.—Invasive plant species observed on FIA P2 plots, Indiana, 2013
90 | FOREST INDICATORS

Figure 76.—Distribution of multiflora rose on FIA P2 Invasive plots, 

Indiana, 2013.

Multiflora 

Rose

Absent

Present

Projection: NAD83, UTM Zone 

16N. Data Source: USDA 

Forest Service Forest Inventory 

and Analysis Program 2013 

Phase 2 invasive data. State 

and county layers source: ESRI 

Data and Maps 10.1. Forest/

nonforest source: Wilson et al. 

2012. Depicted plot locations 

are approximate. Cartography: 

C.M. Kurtz. July 2015.

Japanese honeysuckle (103 plots) were also found on a large number of plots. Eight of 

the 40 monitored IPS were found on 10.0 percent or more of the P2 Invasive plots. 

Overall, 90.7 percent of the monitored plots had one or more IPS with the number of 

IPS per plot ranging from 0 to 10. The largest percentage of plots had two monitored 

invasive plants present (Fig. 77). The distribution of plots with five or more IPS 

present is fairly homogeneous throughout the State (Fig. 78). When comparing 

invasive plant species in Indiana from the 2013 inventory cycle to previous reports 

from 2007-2008, the three most common invasive species (multiflora rose, nonnative 

bush honeysuckles, and Japanese honeysuckle) remained the same for this inventory. 

However, the fourth and fifth most common species switched. Previously the fourth 

most commonly observed species was garlic mustard; currently it is Nepalese 

browntop. In addition, there was an increase in the percentage of plots where the 12 

most commonly recorded invasive plant species were observed. The actual increase in 

number of plots varied by species. 
 | 91

0 

10 

20 

30 

40 

50 

60 

70 

80 

90 

0 1 2 3 4 5 6 7 8 9 10 

Number of Inventory Plots 

Number of Invasive Plant Species 

Figure 77.—Number of invasive plant species per P2 Invasive 

plot, Indiana, 2013.

Figure 78.—P2 Invasive plots with five or more invasive plant species, 

Indiana, 2013.

Number of 

Invasive Plant 

Species per Plot

5

6

7

8

9

10

Projection: NAD83, UTM Zone 16N. Data Source: 

USDA Forest Service Forest Inventory and 

Analysis Program 2013 Phase 2 invasive data. 

State and county layers source: ESRI Data and 

Maps 10.1. Forest/nonforest source: Wilson et al. 

2012. Depicted plot locations are approximate. 

Cartography: C.M. Kurtz. July 2015.
92 | FOREST INDICATORS

What this means

The number of invaded plots in Indiana forests is similar to neighboring Ohio where 

93.2 percent of the plots had one or more of the monitored invasive plant species 

(Widmann et al. 2014). The substantial presence of IPS within Indiana’s rich forests 

is a concern, and it is important that these species are monitored over time to ensure 

that managers and the general public are aware of their occurrence and spread. Further 

investigation of the inventory data may help to reveal influential site and regional 

trends. Invasive plants are good competitors and are able to alter forested ecosystems 

by displacing native species and impacting the fauna that depend upon them. Several 

factors contribute to their success such as prolific seed production, ability to propagate 

vegetatively, rapid growth rate, and ability to survive in harsh conditions. Many factors 

contribute to forest invasion including ungulates, development, fragmentation, and 

timber harvesting. When forests are invaded, they negatively affect the carbon budget 

by reducing future tree cover. Furthermore, these species can have negative economic 

implications by reducing timber yield and aesthetic beauty. 

Forest Related Injurious Agents

Background

Insect and disease activity as well as abiotic factors shape the structure and 

composition of forests. Status monitoring is an important part of assessing the current 

state and monitoring changing trends in Indiana forests. It also provides a valuable 

means of maintaining healthy, vigorous forests and managing future forest resources. 

What we found

A number of common injurious tree insect pests, tree diseases, and other tree related 

injurious agents were present in Indiana forests during the 2013 survey period 

(Table 11). The recurring forest health issues of most concern include gypsy moth 

(Lymantria dispar) management in northern tier counties spanning to Michigan, 

oak wilt (Ceratocystis fagacearum) in northwestern Indiana, emerald ash borer 

(Agrilus planipennis Fairmaire) spread and ash mortality, yellow-poplar mortality 

in southern Indiana, and the impacts of butternut canker (Sirococcus clavigignentijuglandacearum), ash yellows (Candidatus fraxinii), white pine root decline (procera 

root rot) caused by the fungus Leptographium procerum (syn. Verticicladiella procera), 

aging pine plantations, and aging hardwood forests across the State. 
 | 93

Insects Diseases and other related agents

Emerald ash borer (Agrilus planipennis Fairmaire) Dogwood anthracnose (Discula destructiva) 

Introduced pine sawfly (Diprion similis) Sycamore, oak, maple, ash anthracnose (Apiognomonia spp.)

Red Headed pine sawfly (Neodiprion lecontei) Hickory mortality (Scolytus quadrispinosus and Ceratocystis sp.) 

Eurpean pine sawfly (Neodiprion sertifer) Redbud canker (Botryosphaeria dothidea) 

Gypsy moth (Lymantria dispar) Verticillium wilt (Verticillium albo-atrum) 

Forest tent caterpillar (Malacosoma disstria) Diplodia tip blight (Diplodia pinea)

Eastern tent caterpillar (Malscosoma Americana) Nutrient deficiency symptoms on pin oak and red maple

Looper complex (Linden Looper Erannis tiliaria) Herbicide injury

Half winged geometer (Phigalia titea) Oak tatters

Slug oak sawfly (Caliroa quercuscoccineae) Ash yellows/ash decline 

Walnut caterpillar (Datana integerrima) Yellow-poplar decline

Yellownecked caterpillar (Datana ministra) Oak wilt (Ceratocystis fagaecarum)

Fall webworm (Hyphantria cunea) Dutch elm disease (Ophiostoma novo-ulmi)

Mimosa webworm (Homadaula anisocentra) Elm yellows (elm phloem necrosis)

Lacebugs (Corythucha spp.) Spruce needle cast (Rhizosphaera, Stigmina, and

Spider mite (Oligonychus Setomelanomma) spp.) 

Horned/Gouty oak gall (Callirhytis cornigera, C. 

quercuspunctata)

White pine root decline (Verticicladiella procera)

Jumping oak gall (Neuroterus sp.)

Tuliptree scale (Toumeyella liriodendri) 

Oystershell scale (Lepidosaphes ulmi)

Japanese beetle (Popillia japonica) 

Locust leafminer (Odontata dorsalis) 

Zimmerman pine moth (Dioryctria zimmermani) 

Red oak borer (Enaphalodes rufulus)

Carpenter worm (Prionoxystus robiniae)

Sugar maple borer (Glycobius speciosus)

Ips bark beetle (Ips pini or Ips grandicollis)

Turpentine beetle (Dendroctonus tenebrans and D. valens)

Larger pine shoot beetle (Tomicus piniperda) 

Table 11.—Common injurious tree insect pests, diseases, and other related agents found in Indiana forests during the 

2013 survey period

Other forest pests not yet encountered in Indiana but of concern for the future 

include exotic pests such as sudden oak death (Phytophthora ramorum), Asian 

longhorned beetle (Anoplophora glabripennis), gold spotted oak borer (Agrilus 

auroguttatus) and other Agrilus spp., the beech bark disease complex (Cryptococcus 

fagisuga Lind and Nectria coccinea var. faginata Lohman), and the red bay wilt 

complex (Raffaelea lauricola and redbay ambrosia beetle [Xyleborus glabratus]) risk to 

Indiana sassafras and spicebush.

Also of concern are invasive plants that have the potential to affect or are already 

affecting Indiana forest regeneration and biodiversity. One native forest pest epidemic, 

forest tent caterpillar (Malacosoma disstria Hubner), causes extensive defoliation. The 
94 | FOREST INDICATORS

tent caterpillar resulted in extensive forest mortality in south eastern Indiana 5-10 

years ago (Marshall 2012), which has increased the regeneration of tree-of-heaven 

(Ailanthus altissima) to the detriment of native species. Kudzu (Pueraria montana var. 

lobata) also continues to be a problem, and the kudzu eradication program run by the 

Indiana Department of Natural Resources, Division of Entomology and Plant Pathology 

continues to eradicate this invasive plant from locations in southern Indiana to the Ohio 

River and eventually out of Indiana.

Seasonal or prolonged drought periods have long been a significant and historical 

stressor in Indiana (Fig. 79). The worst drought on record occurred in 1936. 

Significant drought has not occurred in the State since 1988, but moderate to 

extreme summer droughts occurred in 1999, 2005, 2007, 2008, 2010, and 2012. The 

drought periods were intermittent with some of the wettest summers on record in 

1979 (wettest on record), 1998, 2004, 2009, and 2011 (NCEI 2015). These periods of 

extreme drought or precipitation can produce conditions that facilitate insect and/

or disease outbreaks and can be even more devastating to trees previously stressed 

by pest damage or other agents. Droughts can cause timber mortality that can occur 

during the year of the drought and for 1 to 5 years after the event. In addition to 

mortality, radial growth loss is another drought impact. The loss of radial growth 

varies with the species and the site conditions (mesic vs. xeric) (Orwig and Abrams 

1997) and has forest management implications. For example, the 2012 drought and 

tuliptree scale (Toumeyella liriodendri [Gmelin]) epidemic in southern Indiana may 

have lessened the total amount of growth; thus without the drought and scale, yellowpoplar growth may have been greater. The drought and scale are also factors that 

contribute to yellow-poplar having the largest amount of removals. 

-6

-4

-2

0

2

4

1895190519151925193519451955196519751985199520052015

PDSI Index

Year

Figure 79.—Palmer Drought Severity Index (PDSI) 3-month average 

(June-August), Indiana, 1895-2014.
 | 95

The forest management implication 

from drought is the stress that trees 

experience. This stress exposes trees 

to attack by other organisms, such as 

twolined chestnut borer, shoestring root 

rot, hypoxylon canker, ips bark beetles, 

red oak borers (Enaphalodes rufulus) 

and other insects and diseases. Thus, 

drought becomes an inciting factor that 

can lead to tree decline, loss of growth, 

and mortality (Starkey, et al. 1989). 

Wet periods of heavy rains and flooding can also cause health problems. Storms and 

tornados can include wind damage, such as the Henryville tornado in 2012, that can 

result in increased foliage disease, uprooting, and other impacts.

What this means

During the survey period, Indiana forests were affected by native and exotic insects, 

disease, floods, winds, and drought. These stressors create weakened trees that are 

vulnerable to secondary attack by other insects and diseases or are the direct cause 

of tree mortality. In combination, there may be significant impacts to tree growth 

and increased risk of forest fire. While efforts to eradicate Asian longhorned beetle 

in neighboring Illinois have proven successful, Indiana forests are experiencing the 

impact of emerald ash borer (see next section) which is dramatically affecting the 

future composition of Indiana forests. For more information about Indiana forest 

insects and diseases, visit http://www.in.gov/dnr/entomolo/.

Ash and Emerald Ash Borer

Background

Emerald ash borer (EAB) was first detected in the United States in the summer of 2002 

near Detroit, MI. Two years later, EAB was found in Steuben County in northeastern 

Indiana, and by the end of 2013, EAB was present in 68 counties, nearly 75 percent 

of Indiana. EAB is an exotic beetle that feeds on the inner bark of ash trees (Poland 

and McCullough 2006). Rapid tree mortality, natural spread, and artificial transport 

of infested materials has resulted in the decline and mortality of millions of ash trees 

across 25 states and 2 Provinces (as of December 2014) (Herms and McCullough 

2014). EAB represents a major threat to the State’s ash resource, typically killing host 

trees within 3 to 5 years of infestation.

Tuliptree scale dripping honey dew. Photo courtesy of Indiana 

Department of Natural Resources, used with permission.
96 | FOREST INDICATORS

What we found

Indiana forest land contains an estimated 148.4 million ash trees greater than 1 inch in 

diameter, a 5 percent increase from 2003. While there is no real spatial pattern to gains 

and losses of ash trees at the county level, fewer counties experienced ash increases in 

2013 than in 2003; thus the rise in ash statewide was the result of gains that occurred in a 

relatively small number of counties (Fig. 80). Ash is present on approximately 2.4 million 

acres, and while total acreage has remained constant, the percentage of ash on Indiana 

forest land has steadily decreased from 52 percent in 2003 to 49 percent in 2013. Rarely 

the most abundant species in a stand, ash generally makes up less than 25 percent of the 

total live-tree basal area (Fig. 81). Ash is found across most of Indiana, with the highest 

densities in the southeast corner of the State (Fig. 82). 

Figure 80.—Change in the number of ash trees on forest land by 

county, and counties positive for EAB, Indiana, (A) 2003 to 2008 

and (B) 2009 to 2013.

A

B

Change in Number of Ash 

2009 to 2013

>50% loss

0 to 50% loss

0 to 50% gain

>50% gain

N/A

EAB positive (2013)

Change in Number of Ash 

2003 to 2008

>50% loss

0 to 50% loss

0 to 50% gain

>50% gain

N/A

EAB positive (2008)
 | 97

0 

200 

400 

600 

800 

1,000 

1,200 

1,400 

1,600 

1,800 

2,000 

0.1-25.0 25.1-50.0 50.1-75.0 75.1-100.0 

Forest Land Area (thousand acres) 

Ash Basal Area (percent) 

2003 

2008 

2013 

1986 

1998 

2003 

2013 

2000 

2005 

2008 

2013 

2008 

2013 

Figure 81.—Forest land area by ash basal area, as a 

percentage of total basal area, by inventory year, Indiana.

Figure 82.—Ash density on forest land, and counties positive for EAB, Indiana, 2013.

Ash Basal Area 

(ft2

/acre)

>30

10 to 29

5 to 9

<5

Nonforest

EAB present

Processing note: This map was produced by 

linking plot data to MODIS satellite pixels 

(250 m) using gradient nearest neighbor 

techniques.
98 | FOREST INDICATORS

Since 2008, mortality of ash trees on forest land has increased by nearly two-thirds, 

averaging close to 1 million trees per year. By volume, this mortality represents an 

annual loss of 11 million cubic feet, an increase of more than 25 percent from 2008. 

Ash mortality occurred across much of Indiana; however, it was largely concentrated 

in counties containing EAB infestations and in the northeast quadrant (Fig. 83). This 

rate of mortality and volume loss is expected to continue through the next 5-year 

inventory cycle (through 2018) and then decrease to normal mortality levels as EAB 

completes its mortality wave through Indiana, which is expected to be completed 

between 2018 and 2020. In most counties, ash mortality accounted for less than 25 

percent of total mortality. 

Ash Mortality

(percent)

EAB present

51 - 75

26 - 50

1 - 25

No mortality

Figure 83.—Percent ash mortality on forest land by county, 

Indiana, 2013, and counties positive for EAB.

Ash Mortality 

(percent)

51-75

26-50

1-25

No mortality

EAB present

What this means

Emerald ash borer is a significant threat to Indiana’s urban, rural, and riparian 

ash resource. EAB is causing significant financial costs to municipalities, property 

owners, and the forest products industry. Although ash yellows disease is present in 

Indiana, EAB is likely to be the largest contributor to ash mortality throughout the 

State. Despite increasing tree numbers, ash mortality continues to rise across the 

State. In some counties where EAB is not yet known to occur, moderate amounts 

of ash mortality are present, suggesting there may be areas with undetected EAB 
 | 99

populations. Ash mortality and the continued identification of new EAB infestations 

will have a considerable impact on the future makeup of Indiana forests. Species 

composition and forest structure will likely undergo changes as ash gives way to more 

maple dominated stands. Continued monitoring of ash resources will help to identify 

the long-term impacts of EAB in Indiana. Overall, EAB may have an impact similar to 

that of Dutch elm disease or chestnut blight.

Black Walnut and Thousand Cankers Disease

Background

Thousand cankers disease (TCD) is a recently described disease complex that is 

considered endemic to the western United States (USDA APHIS 2009). Affecting 

walnut species, TCD results from the interaction between the Geosmithia morbida

fungus and the walnut twig beetle (Pityophthorus juglandis). The beetles bore into 

walnut branches, and while feeding on the tree’s tissues, they deposit the fungus that 

creates a canker, or dead area, under the bark. Multiple feedings cause the formation 

of thousands of cankers under the bark and destroy the tree’s ability to transport water 

and nutrients. Gradually the tree dies. TCD has been introduced to several eastern 

states including Tennessee, Virginia, Ohio, and Pennsylvania. In Indiana, the U.S. 

Forest Service confirmed the fungus in December 2013 from a 2011 study of pests 

coming to stressed black walnut. The Geosmithia morbida fungus was detected on a 

small weevil (Stenomimus pallidus) collected from a stressed black walnut, but the 

fungus was not detected in the tree. The walnut twig beetle, the known insect vector 

of the fungus, was not detected in the stressed walnut trees; however, the walnut twig 

beetle was detected at a sawmill in Franklin County in 2015. 

What we found

The density of black walnut is low across Indiana, with areas of higher concentration 

in the northwest and southeast (Fig. 84). There are an estimated 40.3 million black 

walnut trees greater than 1 inch in diameter on forest land, which account for 317.6 

million cubic feet of volume. Average annual harvest removals of black walnut 

sawtimber total approximately 2 million board feet. Mortality of black walnut growing 

stock on timberland has increased by 16 percent since 2003 and currently totals 

approximately 510,000 cubic feet per year (Fig. 85); however, the ratio of mortality to 

volume is low at 0.2 percent.
100 | FOREST INDICATORS

Figure 84.—Black walnut density on forest land, Indiana, 2013.

Black Walnut 

Basal Area 

(ft2

/acre)

>30

10 to 29

5 to 9

<5

Nonforest

Processing note: This map was 

produced by linking plot data to MODIS 

satellite pixels (250 m) using gradient 

nearest neighbor techniques.

0 

100 

200 

300 

400 

500 

600 

2002 2004 2006 2008 2010 2012 2014 

Mortalitly (thousand ft3/year) 

Year 

Figure 85.—Average annual mortality of black walnut growing-stock 

volume on timberland by inventory year, Indiana.
 | 101

What this means

Black walnut is widely distributed, and therefore makes up an important piece of 

Indiana’s forested landscape. Walnut trees affected by the thousand cankers disease 

typically die within 2 to 3 years after symptoms are noticed.

As a commercial species, black walnut is considered a high value tree species in the 

State based on the dollar value of wood produced, mainly as walnut veneer, timber, 

and nuts. Approximately 17.7 million board feet of black walnut is harvested annually 

with a value of $21.4 million. If all forest walnuts in Indiana were lost because of 

TCD, it would represent a $1.7 billion loss. The estimates do not include the value 

of urban trees and investments in black walnut plantations and tree improvement 

made by landowners over the past 30 years. Therefore, the introduction of TCD has 

the potential to cause extensive walnut mortality and dramatically impact Indiana’s 

forest ecosystem and timber industry. Landowners and homeowners are encouraged 

to visually inspect their walnut trees for presence of thousand cankers disease. The 

earliest symptom is yellowing foliage that progresses rapidly to brown wilted foliage, 

and finally branch mortality. Other major symptoms of this disease are numerous 

small cankers on branches and the bole, and evidence of tiny bark beetles. Additional 

information about thousand cankers disease and quarantine restrictions in Indiana 

can be found at http://www.thousandcankers.com/state-info.php?state=Indiana, 

http://www.in.gov/dnr/entomolo/index.htm, and www.thousandcankers.com/.

Regeneration Status 

Background

The composition and abundance of tree seedlings drives the sustainability of forest 

ecosystems in the early years of stand development and sets the stage for future 

composition and structure, and hence, the viability of timber and ecosystem services 

provided, including clean water, carbon sequestration, and sense of place. Forest 

systems of Indiana face numerous regeneration stressors (e.g., invasive plants, insects, 

diseases, herbivory, and weather). As stands that make up these systems mature and 

undergo stand replacement disturbances, it is imperative to know the viability of the 

regeneration component. Although artificial methods (planting or seeding) are an 

option in some stands, Indiana is dominated by forest systems that regenerate naturally. 

In most situations, establishing desirable reproduction is the key to replacing stands in 

need of replacement with high-canopy species that meet manager’s objectives (Nyland 

2002, Smith et al. 1997, Wenger 1984). Tending of young stands to control composition
102 | FOREST INDICATORS

and stocking levels is also an important consideration. Regeneration data are critical 

for understanding and projecting future forest characteristics that ultimately determine 

sustainability of the full suite of forest values available from Indiana forests. 

To address the need for more detailed information on regeneration, the Northern 

Research Station, Forest Inventory and Analysis program has added advance tree 

seedling regeneration (ATSR) sampling protocols to collect data on a subset of NRSFIA sample plots measured during the growing season (McWilliams et al. 2015). The 

procedures measure all established tree seedlings less than 1 inch in diameter at breast 

height by height class and include a browse assessment for the area surrounding the 

sample location. Results and analysis presented are for regeneration data collected on 

48 sample plots in 2012 and 2013.

What we found

White-tailed deer impact the abundance and composition of the regeneration 

component of Indiana forests through selective browsing of tree seedlings that 

removes more palatable species (oaks) and leaves less palatable species to occupy 

growing space (Wakeland and Swihart 2009). Browsing also has parallel impacts on 

vegetation of the forest understory. Results of the browse impact assessment indicated 

a medium level of browse impact on understory plants for 86 percent of the samples 

(Fig. 86a). Examination of the spatial distribution of browse impact did not reveal any 

distinct pattern other than localized impacts and a few samples with high impact in 

southern Indiana (Fig. 86b). 

The total number of seedlings in Indiana is estimated at 18.2 billion, or an average of 

1,051 seedlings per acre (Fig. 87a, b). Sixty-two percent of the seedlings are less than 

1 foot tall, 32 percent are 1.0 to 4.9 feet, and 6 percent are 5.0 feet and taller. Overall, 

seedling abundance appears to be higher in southern Indiana; however, the number of 

samples is relatively small (Fig. 88). 

White ash, sugar maple, black cherry, slippery elm, and sassafras are the top five 

seedlings in terms of abundance (Fig. 89a, b). Black willow is a top species but 

is subject to a sampling error of 98 percent that precludes meaningful analysis. 

Other species ranked in the top 20 most abundant seedlings that typically have the 

ability to reach the dominant overstory are yellow-poplar, red maple, bitternut and 

pignut hickory, American beech, black oak, and chinkapin oak (Burns and Honkala 

1990). Species that are less desirable or do not form high canopy forests are eastern 

hophornbeam, hackberry, blackgum, eastern redbud, boxelder, and flowering 

dogwood. These species are most prevalent in smaller height classes.
 | 103

0 10 20 30 40 50 60 70 80 90 100

High

Medium

Low

Percent

Browse Impact

Figure 86.—Percentage (A) and distribution (B) of forested P2+ 

samples on forest land by browse impact class, Indiana, 2012-

2013. Error bars represent 1 standard error or a 68 percent 

confidence interval around the mean.

A

B Browse Impact

 Nonforest

 Low

 Medium

 High

(Plot locations are 

approximate)
104 | FOREST INDICATORS

0 2 4 6 8 10 12 14

2.0-11.9 inches

1.0-4.9 feet

> 5.0 feet

Number of Seedlings (billion)

A

BHeight Class

0 500 1,000 1,500 2,000 2,500 3,000 3,500

2.0-11.9 Inches

1.0-4.9 feet

> 5.0 feet

Number of Seedlings per Acre

Height Class

Figure 87.—Total number of seedlings (A) and average number of 

seedlings per acre (B) on forest land by height class, Indiana, 2012-

2013. Error bars represent 1 standard error or a 68 percent confidence 

interval around the mean.

Seedlings per Acre

 0 to 5,000

 5,001 to 10,1000

 >10,000

(Plot locations are 

approximate)

Figure 88.—Distribution of forested P2+ samples on forest land by 

number of seedlings per acre, Indiana, 2012-2013.
 | 105

Mulberry spp.

Hawthorn spp.

American hornbeam

Silver maple

Ohio buckeye

White oak

American elm

Northern red oak

Chinkapin oak

Flowering dogwood

Black oak

Boxelder

Pawpaw

Eastern redbud

American beech

Hackberry

Blackgum

Pignut hickory

Bitternut hickory

Red maple

Eastern hophornbeam

Yellow-poplar

Sassafras

Slippery elm

Black willow

Black cherry

Sugar maple

White ash

0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000

Number of Seedlings (millions)

Species

0 200 400 600 800 1,000 1,200

Mulberry spp.

Hawthorn spp.

American hornbeam

Silver maple

Ohio buckeye

White oak

American elm

Northern red oak

Chinkapin oak

Flowering dogwood

Black oak

Boxelder

Pawpaw

Eastern redbud

American beech

Hackberry

Blackgum

Pignut hickory

Bitternut hickory

Red maple

Eastern hophornbeam

Yellow-poplar

Sassafras

Slippery elm

Black willow

Black cherry

Sugar maple

White ash

Number of Seedlings per Acre

Species

Figure 89.—Number of seedlings (A) and average number of seedlings per 

acre (B) on forest land by species for species with at least 1 percent of the total 

number of seedlings, Indiana, 2012-2013. Error bars represent 1 standard error 

or a 68 percent confidence interval around the mean.

B

A
106 | FOREST INDICATORS

Comparing species abundance using the percentage of the total number of trees by 

height and diameter class highlights potential pathways for future canopy dominants. 

The 10 most common species of dominant/codominant saplings and growing-stock 

trees using aboveground biomass as the importance value are depicted in Figure 90. 

Prospective “gainers” are those species with relatively high percentages of stems in 

the regeneration pool of seedlings and saplings compared to adult trees. Sugar maple, 

white ash, and red maple are the most apparent gainers. Expectations for white ash 

should be tempered with information on the demise of ash due to impacts of the 

emerald ash borer. Prospective “losers” in the process of developing future canopy 

dominants are species with lower percentages in the regeneration pool than the 

canopy pool. Potential losers are yellow-poplar, white oak, black oak, northern red 

oak, and shagbark hickory. American sycamore and pignut hickory fall between the 

gainer and loser categories.

0

10

20

30

40

50

60

70

80

90

100

Percent

Red maple

Pignut hickory

American sycamore

Shagbark hickory

Northern red oak

White ash

Black oak

Sugar maple

White oak

Yellow-poplar

Other 

2.0-11.9 inches

1.0-4.9 feet

5 feet and larger

2

4

6

8

10

12

14

1618

20

21.0-28.9 

29.0+ 

Seedling Length ------------------ Diameter Class (inches) --------------

Figure 90.—Species composition for seedlings, dominant/

codominant saplings, and growing-stock trees on forest land for 

select species, Indiana. Seedling estimates are for 2012-2013. 

Sapling and tree estimates are for 2009-2013. Species shown are 

the top 11 in terms of total aboveground biomass.

What this means

Early successional forest habitat is critically important for providing unique plant 

biota, wildlife food and cover, and landscape heterogeneity (Greenberg et al. 2011). 

Stambaugh (2014) lists native species of small reptiles, mammals, moths, butterflies, 

ruffed grouse (Bonasa umbellus), American Woodcock (Scolopax minor), and 

migratory songbirds as dependent on young forest habitat. A variety of bat species 

are also known to feed on insects common to young forests (Loeb and O’Keefe 2006). 

The quality of Indiana’s early successional stands depends on the composition of the 
 | 107

regeneration component that sets the stage for future benefits from mature forests, 

such as timber, carbon sequestration, and water quality. 

An abundance of seedlings and saplings suggest that the forests of Indiana will 

be resilient as existing young forests develop and as new stands are established 

following harvest or other stand replacement events. This coupled with the finding 

that most of the regeneration indicator samples have medium browse impact sets 

the stage for positive results; however, some local areas are under heavy pressure 

from deer and this is a serious threat to successful regeneration (Rathfon and Farlee 

2002, Stewart 2011). So far, indications are positive for sugar maple, red maple, 

and white ash. The situation with ash will require monitoring because it is found in 

several forest types, but especially because it is a principal cohort of the elm/ash/

cottonwood forest-type group, Indiana’s second most important group found on 

13 percent of the forest land. The most important regeneration issue revealed by 

the regeneration indicator is that black oak, northern red oak, yellow-poplar, and 

white oak are currently underrepresented in the seedling and sapling regeneration 

component. This is important because these four species contribute more than 

one-fourth of the aboveground biomass of the oak/hickory forest-type group, 

which accounts for nearly three-fourths of Indiana forest land. Oak and hickory 

regeneration is well known as an issue (Abrams 1992, Holt and Fischer 1979, 

Lorimer 1993) and management techniques for successful regeneration have been 

described (Brose et al. 2008, Dey et al. 2010, Weigel et al. 2012). Another concern 

is the impact that regeneration has on the future of species important for spring, 

summer, and fall roosting of Indiana bats (Myotis sodalis), particularly in proximity 

to hibernacula. Along with the oaks mentioned, shagbark hickory is preferred by 

Indiana bats for maternity colonies (Menzel et al. 2001, Pruitt and TeWinkel 2007) 

and is underrepresented in the regeneration component. Loss of habitat has been 

listed as an important factor in population reductions in the past (Pruitt and King 

2013, Womack et al. 2013), so forest management will need to consider these and 

other preferred species during the regeneration phase of forest development. 

As Indiana forests grow older, the area of young forest continues to shrink. The 

sapling-seedling (small) stand-size class is a useful surrogate for young forests. 

The current distribution of timberland by size class is 7 percent small (seedling/

sapling), 15 percent medium (poletimber), and 78 percent large (sawtimber). This 

compares with the 12 percent and 8 percent small stand-size class in the adjoining 

central states of Ohio and Illinois, respectively. The area of timberland in the small 

stand-size class decreased from 24 percent of the State’s timberland in 1967 to only 

7 percent currently (Spencer 1969). The current distribution of stand-size classes 

is not sustainable over the long term because of a lack of healthy young forest to 

replace Indiana’s aging forests. This means that at some point, mature forests will 
108 | FOREST INDICATORS

experience either anthropogenic or natural stand replacement events, such as harvest 

or mortality, and will require regeneration to establish new young forests. A more 

balanced distribution of stand-size classes that would support a more diverse mix 

of flora and fauna, as well as improve timber production, would be 20 percent of 

timberland in small stands, 30 percent medium, and 50 percent large. This equates to 

roughly a three-fold increase in the area of young forests. Using age as the surrogate 

for young forest, only 3 percent of Indiana forest land is in the 0 to 10 year age class. 

Clearly, forest regeneration will be the key to successful establishment of new young 

forests. Sound forest management, policy, and planning will ensure a sustainable 

future for Indiana’s treasured forest resources and values for the rest of this century. 

The results presented here reflect only two of the seven panels of measurements 

(48 sample plots) that will eventually make up the first full baseline dataset for 

the regeneration indicator. The full dataset will allow more detailed analyses by 

improving the level of statistical confidence in the estimates (i.e., narrower confidence 

intervals) and will facilitate research to evaluate plot-level regeneration adequacy for 

the major forest-type groups and future trends in composition, structure, and health 

of Indiana forests.

Wildlife Habitat

Forests, woodlands, and savannas provide habitats for many species of Indiana birds 

(117), mammals (44), and amphibians and reptiles (61) (NatureServe, n.d.). Different 

forest types at different structural stages provide natural communities (habitats) at a 

coarse filter scale of conservation. Rare, imperiled, or wide-ranging wildlife species 

may not be fully served at this scale, so a fine filter approach is used to identify 

species-specific conservation needs. Representing an intermediate, or meso-filter, 

scale of conservation are specific habitat features (e.g., snags, riparian forest strips) 

which may serve particular habitat requirements for multiple species.

Like all states, Indiana has developed a State wildlife action plan (SWAP), known 

as the “Indiana Comprehensive Wildlife Strategy” (Gremillion-Smith 2005), 

supplemented by “Forests: Habitat Summary” (IDNR and IFW, n.d.). The summary 

lists 45 species of greatest conservation need (SGCN) in forests, including 18 birds, 16 

mammals, 7 reptiles, and 4 amphibians. High-priority conservation actions for forests 

are also listed: maintain or create landscapes dominated by forest in order to provide 

for needs of area sensitive species, retain forest corridors to connect forest blocks, 

and encourage sustainable timber management practices to provide a variety of forest 
 | 109

stages for the wide variety of forest-dependent species. We report on the condition 

and trends in forest attributes of forest age and size. Of particular note are the State’s 

11 bat SGCN, including Indiana bat, a federally listed endangered species, and 

northern long-eared bat (Myotis septentrionalis), a federally listed threatened species. 

Both species hibernate in caves during the winter but roost during the summer 

under peeling bark, in cavities, or in crevices of both live and dead trees. To address 

conservation issues associated with the presence and abundance of snags and nest 

cavities, we report on the quantity and distribution of standing dead trees. 

Forest Age and Stand Size 

Background

Some species of wildlife depend upon early successional forests consisting of smaller, 

younger trees, while others require older, interior forests containing large trees with 

complex canopy structure. Yet other species inhabit the ecotone (edge) between 

different forest stages, and many require multiple structural stages of forests to meet 

different phases of their life history needs. Abundance and trends in structural and 

successional stages serve as indicators of population carrying capacity for wildlife 

species (Hunter et al. 2001). Historical trends in Indiana forest habitats are reported 

for timberland, which makes up almost 97 percent of all forest land in the State. For 

current habitat conditions, estimates are reported for all forest land.

What we found 

Timberland area in the small-diameter stand-size class decreased substantially 

in Indiana between 1986 and 1998 and has decreased slightly more in the past 15 

years (Fig. 91). In contrast, area in the large diameter stand-size class has increased 

consistently since 1986, exceeding the rate of increase in total timberland area. The 

current area in the medium diameter stand-size class is similar to 1986, with slight 

increases during the intervening years. The current area of timberland under 20 years 

of age is nearly identical to 1998, but only one-third the abundance in 1986 (Fig. 92). 

Timberland older than 100 years represents the smallest area of any age class, 

decreasing in abundance between 1986 and 2003, but increasing since then. The 

greatest increase in timberland area was in the 61-80 year age class, which added over 

800,000 acres. 
110 | FOREST INDICATORS

0 

1 

2 

3 

4 

5 

1986 1998 2003 2008 2013 

Timberland Area (million acres) 

Year 

Nonstocked 

Small diameter 

Medium diameter 

Large diameter 

Figure 91.—Area of timberland by stand-size class and 

inventory year, Indiana.

0 

500 

1,000 

1,500 

2,000 

2,500 

3,000 

3,500 

4,000 

4,500 

5,000 

1986 1998 2003 2008 2013 

Timberland Area (thousand acres) 

Year 

Not measured 

100+ years 

81-100 years 

61-80 years 

41-60 years 

21-40 years 

0-20 years 

Figure 92.—Area of timberland by stand-age and inventory year, Indiana.

In Indiana, all three stand-size classes contain forests from at least four age classes. 

The medium stand-size class is predominated by forests 21 to 60 years of age, with 

lower amounts of both younger and older forest. The large stand-size class has an 

age distribution skewed further to the right, predominated by trees in the 61-80 year 

age class. Young forest (0-20 years) makes up the greatest area in the small diameter 

stand-size class, with decreasing area in successively older age classes (Fig. 93).
 | 111

0 

200 

400 

600 

800 

1,000 

1,200 

1,400 

Small diameter Medium diameter Large diameter 

Forest Land Area (thousand acres) 

Stand-size Class 

0-20 years 

21-40 years 

41-60 years 

61-80 years 

81-100 years 

100+ years 

Figure 93.—Area of forest land by stand-size class, Indiana, 2009-2013.

What this means 

In Indiana, an increase in the area of timberland in the large diameter stand-size 

class comes at the expense of area in the medium diameter stand-size class. Similarly, 

the area of timberland of at least 60 years of age increased while the abundance of 

timberland less than 40 years of age decreased. The small diameter stand size-class 

and 0-20 year age class provide two similar, but not identical, indicators of early 

successional habitat. More than 68 percent of 0-20 year old forest is in the small 

diameter size class, and 51 percent of small diameter forest is 0-20 years of age. 

Although both indicators have been relatively stable during the past 15 years, both are 

substantially lower in abundance than in 1986. Two bird SGCN are used to illustrate 

potential effects of changing forest structure. Mature forest species like cerulean 

warbler (Dendroica cerulea) benefit from increases in late-successional habitat, while 

early successional species, like golden-winged warbler (Vermivora chrysoptera), suffer 

from losses to their required habitats. As expected, there is almost no small forest 

in stand ages over 60 years of age and very little in forest older than 40 years; these 

age classes are predominated by the large diameter stand-size class. The 21-40 year 

old class is predominated by the medium diameter stand-size class but also contains 

substantial area in both large and small diameter classes. Such mixtures of different 

aged or sized trees provide a vertical diversity of vegetation structure that can enhance 

habitat conditions for some species. Managing forest conditions in both younger and 

older age classes (and smaller and larger structural stages) to maintain both early 

and late successional habitats may conserve habitat and viable populations of many 

forest-associated wildlife species. Another important benefit of offering a variety of 

successional stages across landscapes is that many species that are known to use late 

successional forest for nesting also use early successional forest patches for foraging. 

This is true for many bird species such as ovenbird and wood thrush that are typically 
112 | FOREST INDICATORS

thought of as late successional species. Also bats that roost in mature forests within 

snags and cavities (e.g., Indiana bats, northern long-eared bats, and little brown bats 

[Myotis lucifugus]) will often forage over early successional openings (little brown 

bats), or along forest edges between early and late successional stands (Indiana and 

northern long-eared bats). Therefore, even species that use late successional habitat 

often use early successional areas to fulfill life requirements, typically for foraging, 

further supporting the need to manage for a variety of forest conditions across 

landscapes.

Standing Dead Trees

Background 

Specific habitat features like nesting cavities and standing dead trees provide critical 

habitat components for many forest-associated wildlife species. Standing dead 

trees that are large enough to meet habitat requirements for wildlife are referred 

to as “snags”. According to one definition, “for wildlife habitat purposes, a snag is 

sometimes regarded as being at least 10 inches (25.4 cm) in diameter at breast height 

and at least 6 feet (1.8 m) tall” (Society of American Foresters 1998). However, both 

federally listed tree roosting bats in Indiana (Indiana and northern long-eared bat) 

will often use snags with smaller diameters, even as small as half the diameter in 

the above definition. Standing dead trees serve as important indicators not only 

of wildlife habitat, but also for past mortality events and carbon storage. They also 

serve as sources of down woody material (discussed elsewhere in this report), which 

provides habitat features for wildlife. The number and density of standing dead trees, 

together with decay classes, species, and sizes, define an important wildlife habitat 

feature across Indiana forests. 

What we found 

FIA collects data on standing dead trees (5 inches d.b.h. and larger) of numerous 

species and sizes in varying stages of decay. More than 54 million standing dead trees 

are present on Indiana forest land. This equates to an overall density of 11.1 standing 

dead trees per acre of forest land, with slightly higher densities on public (11.9) than 

on private (10.9) forest land. The density of standing dead trees per acre of timberland 

on private ownerships has declined from 15.1 in 1986 to 11.1 in 2013, with even 

greater declines on public forest ownerships (Fig. 94). 
 | 113

0 

2 

4 

6 

8 

10 

12 

14 

16 

18 

20 

1986 1998 2003 2008 2013 

Standing Deaed Trees 

(number per acre of timberland) 

Inventory Year 

Public 

Private 

Figure 94.—Number of standing dead trees per acre of timberland 

by ownership and inventory year, Indiana.

Thirteen species groups each contributed more than 1 million standing dead trees. 

The top group, other eastern soft hardwoods, contributed more than 21 million 

standing dead trees (Fig. 95). Eight species groups exceeded 10 standing dead trees 

per 100 live trees (5 inches and larger d.b.h./d.r.c) (Fig. 96). More than 77 percent of 

standing dead trees were smaller than 11 inches d.b.h., 43 percent were between 5 and 

6.9 inches d.b.h., and only 6 percent were over 17 inches (Fig. 97). The predominant 

dead tree decay class for most diameter classes was “only limb stubs present,” which 

was observed on 31 percent of the trees, on average. Only 6 percent of the dead trees 

had the highest decay class, “no evidence of branches remain” (Fig. 97).

0 10 20 

Other eastern soft hardwoods 

Ash 

Other eastern hard hardwoods 

Yellow-poplar 

Other red oaks 

Select white oaks 

Soft maple 

Hard maple 

Other eastern softwoods 

Eastern noncommercial hardwoods 

Hickory 

Eastern white and red pine 

Other yellow pines 

Black walnut 

Select red oaks 

Cottonwood and aspen 

Loblolly and shortleaf pine 

Sweetgum 

Other white oaks 

Tupelo and blackgum 

Number of Standing Dead Trees (millions) 

Species

Figure 95.—Number of standing dead trees (5 inches d.b.h. 

and larger) by species group, Indiana, 2013.
114 | FOREST INDICATORS

0 5 10 15 20 25 30

Other yellow pines

Loblolly and shortleaf pine

Other eastern hard hardwoods

Other eastern soft hardwoods

Eastern white and red pine

Eastern noncommercial hardwoods

Cottonwood and aspen

Ash

Other red oaks

Other eastern softwoods

Select white oaks

Other white oaks

Yellow-poplar

Select red oaks

Sweetgum

Soft maple

Tupelo and blackgum

Basswood

Black walnut

Hickory

Number of Standing Dead Trees by species group 

per 100 Live Trees 

Species

Figure 96.—Number of standing dead trees (5 inches d.b.h. and 

larger) per 100 live trees by species, Indiana, 2013.

0

1

2

3

4

5

6

7

5.0-6.9

7.0-8.9

9.0-10.9

11.0-12.9

13.0-14.9

15.0-16.9

17.0-18.9

19.0-20.9

21.0-28.9

29.0+

Number of Standing Dead Trees (millions)

Diameter Class (inches)

All limbs and branches present

Few limbs and no fine branches

Only limb stubs present

Few or no limb stubs remain

No evidence of branches remain

Figure 97.—Distribution of standing dead trees (5 inches d.b.h. 

and larger) by decay and diameter classes, Indiana, 2013.

What this means

Standing dead trees result from a variety of potential causes, including diseases, 

insects, weather damage, fire, flooding, drought, and competition. Frequency of 

standing dead trees has decreased over the past 25 years, on both public and private 

timberland. Because dead trees may contain significantly more cavities per tree 
 | 115

than occur in live trees (Fan et al. 2003), they provide habitat for foraging, nesting, 

roosting, hunting perches, and cavity excavation for a range of wildlife, including 

primary colonizers such as insects, bacteria, and fungi to birds, mammals, and 

reptiles. Most cavity nesting birds are insectivores which help to control insect 

populations. The availability of very large standing dead trees (snags) in Indiana may 

be a limiting meso-scale habitat feature for some species of wildlife. For example, the 

Indiana bat clearly uses snags more than live trees, and the most important roosts 

used in maternity colonies (i.e., primary roosts) are often snags typically greater 

than 12 inches d.b.h. (Pruitt and TeWinkel 2007). In contrast, the northern longeared bat is not limited or specialized in roost selection and is described as a roost 

generalist since it roosts in a wide variety of conditions (e.g., live or dead trees, under 

bark or in cavities/crevices, small or large diameter trees). See the next section for 

more information about bat habitat. Providing a variety of forest structural stages 

and retaining specific features like snags on both private and public lands are ways 

that forest managers can maintain the abundance and quality of habitat for forestassociated wildlife species in Indiana.

Bat Forest Habitat

Background

Although many bat species hibernate in caves during winter months, forests provide 

critical habitat to these fauna during their active seasons. Habitat selection in part 

occurs based on site-specific, stand-level, and landscape-scale levels of habitat 

perception. All bats in Indiana use forests (or woodlands, woodlots, riparian 

corridors, etc.). Eastern red (Lasiurus borealis) and hoary (Lasiurus cinereus) bats 

produce young in foliage of trees. Silver-haired bats (Lasionycteris noctivagans) 

migrate through Indiana and produce their young farther to the north. Indiana and 

northern long-eared bats regularly form maternity colonies under the loose bark of 

trees. Also, any of the bats that form maternity colonies in buildings may presumably 

use hollow trees as well. Indiana’s cave bats include: the gray (Myotis grisecens), 

eastern small-footed (Myotis leibii), little brown, northern long-eared, Indiana, 

tricolored (Perimyotis subflavus), southeastern (Myotis austroriparius) and big brown 

(Eptesicus fuscus). Indiana’s tree bats include: silver-haired, eastern red, hoary, evening 

(Nycticeius humeralis), and Rafineque’s big-eared (Corynorhinus rafinesquii). 

Habitat requirements for bats of Indiana are not completely understood. For example, 

the Indiana bat summer habitat includes small to medium river and stream corridors 
116 | FOREST INDICATORS

with well-developed riparian woods, woodlots within 1 to 3 miles of small to medium 

rivers and streams, and upland forests. The Indiana bat is a tree bat that requires 

forested areas for foraging and roosting; however, at a landscape level Indiana bat 

maternity colonies occupy habitats ranging from completely forested to areas of 

highly fragmented forest (Pruitt and TeWinkel 2007). Studies by Menzel et al. (2001) 

and King (2006) have identified at least 33 tree species that Indiana bats use during 

the summer. Roost trees are mainly in the oak/hickory cover type, but include a 

variety of species (Luensmann 2005, Pruitt and TeWinkel 2007, Rommé et al. 1995). 

Tree structure is probably more important than the species in determining if a tree is 

a suitable roost site. Tree species that develop loose, exfoliating bark as they age and 

die are likely to provide roost sites. Male bats disperse throughout the range and roost 

individually or in small groups. In contrast, reproductive females form larger groups, 

referred to as maternity colonies, in which they raise their offspring (Pruitt 2001). 

Although some alternate roosts occur in living trees (e.g., shagbark hickory), most 

Indiana bats roost in dead or dying trees. The Indiana bat forages around tree canopies, 

within open forest, along forest edges, forest openings, and riparian areas; typically less 

than 2.5 miles from the roost. Rommé et al. (1995) suggests that foraging habitat would 

ideally have 50 to 70 percent tree canopy closure. The 2007 Indiana bat recovery plan 

provides a good reference for foraging habitat (Pruitt and TeWinkel 2007). 

The species, size, solar orientation, and live/dead status of trees as well as bat gender, 

also appear to contribute to preferred Indiana bat habitat. The Indiana female bat 

generally prefers large, standing dead hardwood species, especially for maternity 

roosting trees. Male roosts do not seem to show a diameter class preference. Both 

genders seemingly roost in snags more often than live trees, but it is not clear if this is 

due to preference or if it is more dependent on availability of better quality roosting 

sites in snags. Although researchers have found it difficult to predict where maternity 

colonies may occur relative to forested habitat, it is a reliable prediction that once 

Indiana bats colonize maternity habitat, they will return to the same maternity areas 

annually (Pruitt and TeWinkel 2007).

When active, all bat species must have daily access to clean water for drinking, 

especially during lactation and periods of increased activity. Bats typically drink on 

the fly. Several species will also arouse to drink during hibernation. Some Indiana 

bat species usually roost near or forage over water. Gray myotis, little brown myotis, 

southeastern myotis, and tri-colored bats prefer to forage over lakes, rivers, and 

ponds. Eastern red bats, hoary bats, Indiana myotis, and big brown bats are known to 

use waterways for travel and foraging.
 | 117

Bat threats

Bats are exceptionally vulnerable to extinction, in part because they are the slowestreproducing mammals on Earth for their size, most producing only one young (pup) 

annually. More than half of American bat species are in decline or already listed as 

endangered. Losses are occurring at alarming rates worldwide. Major historic and 

chronic threats include natural predation (e.g., raccoons, feral cats, and snakes), 

habitat loss and fragmentation, cave and mine disturbance, toxicants (pesticides), 

and pollutants (including light pollution). Many bats die by accident. They can 

get impaled on barbed wire and burdocks or drown in floods during hibernation. 

Timber harvesting is not considered a primary threat to bat populations. When 

properly designed, many types of timber management do not impact, and may 

actually improve, bat habitat. Generally, forest management is considered compatible 

with maintenance of bat summer habitat, provided that key components of summer 

habitat are part of the forest management system (Pruitt and TeWinkel 2007). Other 

threats include turbines for wind energy, and for cave dwellers, the most severe and 

immediate threat is white-nose syndrome.

White-nose syndrome in bats 

White-nose syndrome (WNS) has devastated bat populations across the eastern United 

States in the years since it was first discovered in a New York cave in February 2006. It 

has caused the most precipitous wildlife decline in the past century in North America 

(Bat Conservation International 2014). White-nose syndrome is an infectious disease 

associated with the fungus Pseudogymnoascus destructans. WNS is named for a hideous 

cold-loving white fungal growth that invades the skin tissue on the muzzle, wings, and 

A cluster of little brown bats exhibiting the symptoms of white-nose syndrome. Photo from New York Department of 

Environmental Conservation, used with permission.
118 | FOREST INDICATORS

ears of cave-dwelling bats during winter hibernation. Airflow between a cave’s entrance 

and exit spreads the disease. As the spores circulate, they land on the bodies of the bats 

in the cave, and when conditions are right, the spores develop into hyphae, which are 

threadlike structures that can invade the skin tissue of the bat.

The disease has caused the death of an estimated 5.7 to 6.7 million bats across eastern 

North America, with estimates of mortality often exceeding 90 percent in caves that 

have experienced multiple years of infection (U.S. FWS 2012). While the prolific white 

fungal growth on the bat’s muzzle may be the most striking sign of infection, it is their 

wings that may be the most injurious target. During hibernation, the large surface 

area of a bat’s wings performs critical physiological requirements such as regulating 

the animal’s body temperature, water balance, and gas exchange with its external 

environment. These life processes, which are vital to survival, are disrupted when 

healthy wing membranes are invaded by the fungus. Consequently, the hibernation 

strategy of WNS-infected bats often includes a number of harmful behaviors. An 

example is exiting caves during cold winter days, which appears to be triggered by 

their inability to regulate essential metabolic activities. White-nose syndrome causes 

bats to awaken more often during hibernation and use up the stored fat reserves that 

are needed to get them through the winter. Infected bats often emerge too soon from 

hibernation and fly around in midwinter, which can lead to them freezing or starving 

to death. For more information, visit http://www.in.gov/dnr/fishwild/.

What we found

With an average of less than one standing dead tree per acre for trees with a d.b.h. 

in excess of 15.0 inches, the density (number per forest land acre) of standing dead 

trees in Indiana forests is limited for larger diameter trees (Fig. 98). As an alternative 

to roosting in snags, Indiana bats may roost under the naturally exfoliating bark of 

living shagbark and shellbark hickories, which average more than one per forest land 

acre for trees with a d.b.h. in excess of 12 inches (Fig. 99). An assessment of potential 

future bat habitat found that the current d.b.h. distribution of live trees of bat 

preferred roost species in Indiana (Pruitt and TeWinkel 2007) averages more than 12 

live trees per forest land acre for trees with a d.b.h. in excess of 12.5 inches (Fig. 100).
 | 119

0.0

1.0

2.0

3.0

4.0

5.0

6.0

5.0-7.5

7.6-10.0

10.1-12.5

12.6-15.0

15.1-17.517.6-20.020.1-22.5

22.6-25.0

25.1+

Standing Dead Trees 

(number per acre)

Diameter Class (inches)

Figure 98.—Density (number/acre) of standing dead trees 

(i.e., snags) by d.b.h. class on forest land, Indiana, 2013. 

Error bars represent 1 standard error or a 68 percent 

confidence interval around the mean.

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

5.0-7.5

7.6-10.0

10.1-12.512.6-15.015.1-17.5

17.6-20.020.1-22.522.6-25.0

25.1+

Standing Live Trees

(number per acre)

Diameter Class (inches)

Figure 99.—Density (number/acre) of standing live shagbark 

and shellbark hickories by d.b.h. class on forest land, Indiana, 

2013. Error bars represent 1 standard error or a 68 percent 

confidence interval around the mean.
120 | FOREST INDICATORS

0.0

5.0

10.0

15.0

20.0

25.0

5.0-7.5

7.6-10.0

10.1-12.512.6-15.015.1-17.517.6-20.020.1-22.522.6-25.0

25.1+

Standing Live Trees 

(number per acre)

Diameter Class (inches)

Figure 100.—Density (number/acre) of standing live oaks, 

maples (excluding boxelder), hickories, eastern cottonwood, 

American elm, slippery elm, and black locust by diameter class 

on forest land, Indiana, 2013. Error bars represent 1 standard 

error or a 68 percent confidence interval around the mean.

What this means

Relatively low densities of large snags may affect the distribution of Indiana bat 

maternity colonies in Indiana but would be less of a concern for northern long-eared 

bat maternity colonies. The female Indiana bat prefers larger standing dead trees, and 

although the current density is relatively low when compared to smaller diameter 

snags, it is not known what density of roosts is necessary to sustain a summer 

population of Indiana bats. There is the potential to increase bat habitat through 

selective management of tree species and/or retention of snags.
Forest Economics

Knob Lake Campground offers inexpensive, primitive, and quiet camping. Nearby Starve Hollow State Recreation Area 

has modern campsites with electric hookups and restrooms with showers. Photo by Indiana Department of Natural 

Resources, used with permission.

 | 121
122 | FOREST ECONOMICS

Carbon Stocks

Background 

Carbon has become a part of forest resource reporting in recent years primarily because 

forests sequester carbon from the atmospheric greenhouse gas carbon dioxide, a gas 

that is linked to global climate change. Among terrestrial ecosystems, forests contain 

the largest reserves of sequestered carbon. Regional and national greenhouse gas 

reporting forums include forest carbon stocks because increases in forest carbon stocks 

represent quantifiable partial offsets to greenhouse gas emissions. For example, carbon 

sequestration by U.S. forests represented an offset of more than 11 percent of total U.S. 

greenhouse gas emissions in 2013 (U.S. EPA 2015), and the continuing increase in 

Indiana forest carbon stocks contributes to this effect. 

Carbon accumulates in growing trees via the photosynthetically-driven production 

of structural and energy-containing organic (carbon) compounds that primarily 

accumulate in trees as wood. Over time, this stored carbon also accumulates in dead 

trees, woody debris, litter, and forest soils. For most forests, the understory grasses 

and forbs as well as nonvascular plants and animals represent minor pools of carbon 

stocks. Within soils, the larger woody roots are readily distinguished from the bulk of 

soil organic carbon, so the roots are generally reported as the belowground portion of 

trees and not included in the soils estimates. Carbon loss from a forest stand can include 

mechanisms such as respiration (including live trees and decomposers), combustion, 

runoff or leaching of dissolved or particulate organic particles, or direct removal such 

as the harvest and utilization of wood. From the greenhouse gas reporting perspective, 

it is important to note that not all losses result in release of carbon dioxide to the 

atmosphere; some wood products represent continued long-term carbon sequestration. 

The carbon pools discussed in this report include living plant biomass (live trees ≥1 

inch d.b.h. and understory vegetation), dead wood and litter (nonliving plant material 

including standing dead trees, down dead wood, and forest floor litter), and soil organic 

matter exclusive of coarse roots and estimated to a depth of 1 meter (3.28 feet). Carbon 

that is stored in harvested forest products such as lumber, plywood, and paper, is not 

included. Carbon estimates by ecosystem pool are based on sampling and modeling; for 

additional information on current approaches to determining forest carbon stocks, see 

U.S. Environmental Protection Agency (2015), U.S. Forest Service (2014a, 2014b), and 

O’Connell et al. (2014). The level of information available for making carbon estimates 

varies among pools. For example, the estimate of live tree carbon has the greatest 

confidence due to the level of sampling and the availability of allometric relationships 

applied to the tree data. Limited data and high variability result in lower confidence 

in the soil organic carbon estimates, which limits the interpretation of these estimates. 

Ongoing research is aimed at improving the estimates (U.S. EPA 2015). The carbon 
 | 123

estimates provided here for Indiana forests are consistent with the data and methods 

used to develop the forest carbon reported in “U.S. Environmental Protection Agency’s 

Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2013” (U.S. EPA 2015).

What we found

Total forest carbon stocks in Indiana are estimated to be 314 million tons, a 4 percent 

increase from 2008 to 2013. Overall, forest carbon per acre increased by 1.6 percent 

relative to 2008, and live tree carbon values increased by 2.5 percent. Live trees and soil 

organic carbon account for nearly 90 percent of forest carbon stocks, and almost onethird of the carbon is in the wood and bark of the bole of trees 5 inches d.b.h. and larger 

(Fig. 101). This represents the average distribution of carbon stocks within Indiana 

forest ecosystems, but individual stands will vary with site conditions and forest types.

Soil organic carbon 37%

Forest floor/litter 5%

Down dead wood 3%

Understory 1%

Standing dead trees 1%

Saplings 3%

Top/branches 8%

Bole 32%

Stump 2%

Coarse roots 8%

Live tree 

carbon 

52%

Figure 101.—Forest carbon stocks on forest land by carbon pool, 

Indiana, 2013. 

Average aboveground carbon per acre increases with stand age, and the greatest net 

accumulation is within aboveground biomass (Fig. 102). More than 60 percent of total 

aboveground carbon stocks are represented by the middle two age classes (over 30 

percent each); in contrast, the 0 to 20 year age class accounts for a little over 10 percent 

of the forest carbon stocks.

The oak/gum/cypress forest-type group, followed by the elm/ash/cottonwood, 

maple/beech/birch, white/red/jack pine, and oak/hickory forest-type groups yielded 

the highest average carbon short tons per acre (Fig. 103). Note that the sometimes 

considerable variability among forest-type groups is most closely associated with 

variability in biomass (which is essentially live tree; see Fig. 101). More than 95 percent 

of the total carbon stocks of Indiana forests are in the four most common forest-type 

groups: oak/hickory, elm/ash/cottonwood, maple/beech/birch, and oak/pine. The largest 

single pool of biomass is within the oak/hickory forest-type group, with 225 million 

short tons of carbon or nearly 70 percent of all Indiana forest carbon stocks.
124 | FOREST ECONOMICS

0 

5 

10 

15 

20 

25 

30 

35 

40 

45 

50 

0-20 21-40 41-60 61-80 81-100 101+ 

Carbon (short tons/acre) 

Stand-age Class (years)

Aboveground deadwood 

and litter 

Aboveground biomass 

Figure 102.—Carbon by stand-age class for aboveground living plant 

biomass (live tree ≥1 inch d.b.h. and understory) versus dead wood 

(standing dead and down dead) and litter pools, Indiana, 2013.

0 10 20 30 40 50 60 70 80 90

White/red/jack pine group

Loblolly/shortleaf pine group

Additional softwood types

Oak/pine group

Oak/hickory group

Oak/gum/cypress group

Elm/ash/cottonwood group

Maple/beech/birch group

Additional hardwood types

Carbon Stocks (short tons per acre)

Forest-type Group C in biomass C in dead wood C in litter Soil organic C

Figure 103.—Carbon stocks by forest-type group and component: 

biomass (live tree and understory), dead wood (standing dead trees and 

down dead wood), litter, and soil, Indiana, 2013. The less common foresttype groups are pooled as additional softwood or hardwood types.

What this means

In general, forest carbon stocks or differences in carbon stocks broadly reflect other 

measures of forest resources such as stand age, volume, or stocking. However, these 

summaries provide a useful reference measure of carbon stocks for the State relative to 

published regional or national forest carbon reports and offer a ready estimate of the 

role of Indiana forests. In brief, the carbon summaries show: (1) most of the carbon is in 

live trees, followed by soil organic carbon; (2) the majority of carbon is in stands of 40 to 

80 years; (3) specific stand-level carbon varies; and (4) overall forest carbon in Indiana 

has increased over the past 5 years.
 | 125

Timber Products Output 

Background

Indiana forests contribute over $16 billion annually to Indiana’s economy. In 2008, 

Indiana’s primary wood-using industry included 155 sawmills, 8 veneer mills, one 

handle plant, and 21 mills producing other products. Direct employment within the 

industry accounted for over 35,000 people and indirectly, the industry supported 

around 90,000 jobs. Forest-based manufacturing provided $2.4 billion in value-added, 

$7 billion in value of shipments, and a payroll of $1.2 billion to Indiana's economy in 

2008. More than two-thirds of the 68.4 million cubic feet of industrial roundwood 

harvested in 2008 came from south-central and southwestern Indiana. Saw logs 

accounted for 90 percent of the total harvest, with other minor products—primarily 

veneer logs, pulpwood, handles, and cooperage—making up the rest (Walters et al. 

2012). The harvesting and processing of timber products produces a stream of income 

shared by timber owners, managers, marketers, loggers, truckers, and processors. In 

2013, the wood products and paper manufacturing industries in Indiana employed 

12,592 people (U.S. Department of Labor 2015), with an average annual payroll of 

$996 million (U.S. Census Bureau 2015). To better manage the State’s forests, it is 

important to know the species, amounts, and locations of timber being harvested.

What we found

A canvass of Indiana’s wood-processing mills is conducted periodically to estimate the 

amount of wood that is harvested and processed into products. The active primary 

wood processing mills in Indiana were last canvassed in 2013. The 2013 canvass found 

that the 143 active primary wood processing mills in Indiana processed 80.2 million 

cubic feet of industrial roundwood, an increase of 17 percent from 2008 (Walters et al. 

2012), but still 8 percent below the 2005 level (Piva and Gallion 2007). Eighty-five 

percent of the industrial roundwood processed by Indiana mills came from Indiana 

forest lands. In 2013, 67.8 million cubic feet of industrial roundwood was harvested 

from Indiana forest land, an increase of 7 percent from 2008 (Fig. 104). 

Saw logs accounted for more for than 93 percent of the total industrial roundwood 

harvested. Other products harvested were veneer logs, pulpwood, cooperage, and 

other miscellaneous products. Yellow-poplar accounted for 20 percent of the total 

industrial roundwood harvest (Fig. 105). Other important species groups harvested 

were the red oaks, white oaks, ash, hard maple, hickory, and black walnut. 

In the process of harvesting industrial roundwood, 54.4 million cubic feet of harvest 

residues were left on the ground, of which nearly a third was merchantable material. 
126 | FOREST ECONOMICS

0 

30 

60 

90 

Saw logs Veneer Pulpwood Other

products 

All

products 

Industrial Roundwood Production 

(million ft3

)

Products 

2000 

2005 

2008 

2013 

1986 

1998 

2003 

2013 

2008 

2013 

Figure 104.—Industrial roundwood production by product and 

year, Indiana.

0 

5 

10 

15 

20 

25 

Yellowpoplar Red 

oak 

White 

oak 

Ash Hard 

maple 

Other 

hardwoods 

Softwoods 

Industrial Roundwood Production 

(million ft3

)

Species Group 

2005 

2008 

2013 

Figure 105.—Industrial roundwood production by species group 

and year, Indiana.

The processing of industrial roundwood generated 1.1 million green tons of wood 

and bark residues. Thirty-three percent of the mill residues generated were used for 

fiber products at pulp and composite panel mills. Another 18 percent of the mill 

residues were used for industrial and residential fuelwood, 11 percent were used for 

animal bedding, 32 percent were used for mulch, and 5 percent were used for other 

miscellaneous products. Only 1 percent of the mill residues generated were not used 

(Fig. 106).
 | 127

Fiber products 

32% 

Industrial 

fuelwood 

Residential 15% 

fuelwood 

3% 

Mulch

32%

Animal 

bedding 

11% 

Other uses 

6% 

Not used 

1% 

Figure 106.—Disposition of mill residues generated by 

primary wood-using mills, Indiana, 2013.

During the recent recession, the number of employees hit its lowest level in 2010, 

while annual payroll (actual dollars) and the total value of shipments (actual dollars) 

bottomed out in 2009. After decreasing by 44 percent between 2004 and 2010, the 

number of employees working in the forest products industry increased by 13 percent 

between 2010 and 2013 (Fig. 107). The annual payroll decreased by 23 percent 

between 2004 and 2009, while the total value of shipments only decreased by 13 

percent. From 2009 and 2013, the annual payroll increased by 15 percent and the total 

value of shipments increased by 21 percent.

0

1,500

3,000

4,500

6,000

7,500

0

5

10

15

20

25

2004 2006 2008 2010 2012

Annual Payroll (million $)

Number of Employees (thousands)

Year

Number of employees Annual payroll Total value of shipments

Figure 107.—Number of employees, annual payroll, and total value of 

shipments for the forest products industry in Indiana, 2004-2013.
128 | FOREST ECONOMICS

What this means

Between 2004 and 2010, the number of employees working in the forest products 

industry decreased 44 percent, but the annual payroll decreased by only 20 percent 

and the total value of shipments by only 6 percent. The demand for higher value forest 

products, such as white oak cooperage and black walnut veneer, much of which is 

being exported out of the Country, kept the overall annual payroll and total value of 

shipments from decreasing as much as the number of employees. As the economy 

improves and the demand for wood products increases, the forest product mills that 

were able to withstand the recession are beginning to increase their production, 

resulting in an increase in the number of employees in the forest products industry. 

Another important issue is the volume of harvest residues that are generated in the 

State that go unused. More than 30 percent of the harvest residue is from growingstock sources (wood material that could be used to produce products). Indiana’s 

primary forest products industry is the processing of saw logs. The last pulp mill in 

the State closed in 2007. This leaves a large volume of usable, small dimension wood 

material above the saw log top that could be utilized by small, localized, industrial 

fuelwood or wood pellet manufactures, leading to better utilization of the forest 

resource.
Future Forests

Yellow-poplar regeneration. Photo by Rich Widman, U.S. Forest Service. 

 | 129
130 | FUTURE FORESTS

Future Land Projections

Background

This section focuses on anticipated changes to the forests of Indiana between 2010 

and 2060. The Northern Forest Futures study (Shifley and Moser 2016) examined 

several alternative future scenarios that cover a range of different assumptions about 

the economy, population, climate, and other driving forces that will affect the future 

conditions of forests. The assumptions were incorporated into analytical models that 

estimate how northern forests are likely to change under each alternative scenario. 

The seven scenarios can be grouped by climate model (or “general circulation 

model”), storyline, and storyline variation. Two climate models, three storylines, 

and three variations were used to produce the seven scenarios (Table 12). Additional 

details on methods can be found in Shifley and Moser (2016).

A large component of future forest change will be the result of normal forest growth, 

aging, natural regeneration, and species succession. In addition, external forces are 

expected to drive forest change: 

• Population increases will cause roughly 370,000 acres of forest land to be converted 

to urban land (Nowak and Walton 2005).

• Economic conditions will affect forest products consumption, production, and 

harvest rates.

• Invasive species will spread and affect forest change.

• Changes in population, the economy, energy consumption, and energy production 

will affect future climate change.

• Climate change will affect patterns of forest growth and species succession.

General circulation model IPCCa Storyline A1B IPCC Storyline A2 IPCC Storyline B2

CGCM3.1b Scenario A1B-C Scenario A2-C 

Scenario A1B-BIO Scenario A2-BIO

Scenario A2-EAB

CGCM2c Scenario B2-C 

Scenario B2-BIO

a IPCC is the Intergovernmental Panel on Climate Change.

b Canadian Centre for Climate Modelling and Analysis, n.d.b. 

c Canadian Centre for Climate Modelling and Analysis, n.d.a. 

Table 12.—Scenarios used to project future forest conditions for Indiana
 | 131

Following are the three storylines, as developed by the Intergovernmental Panel on 

Climate Change (IPCC 2000), with a brief description of the characteristics of each:

1) A1B—Rapid economic globalization. International mobility of people, ideas, and 

technology. Strong commitment to market-based solutions. Strong commitment to 

education. High rates of investment and innovation in education, technology, and 

institutions at the national and international levels. A balanced energy portfolio 

including fossil intensive and renewable energy sources. Uses the CGCM3.1 

climate model (Canadian Centre for Climate Modelling and Analysis, n.d.b).

2) A2—Consolidation into economic regions. Self-reliance in terms of resources 

and less emphasis on economic, social, and cultural interactions between regions. 

Technology diffuses more slowly than in the other scenarios. International 

disparities in productivity, and hence income per capita, are largely maintained or 

increased in absolute terms. Uses the CGCM3.1 climate model.

3) B2—A trend toward local self-reliance and stronger communities. Communitybased solutions to social problems. Energy systems differ from region to region, 

depending on the availability of natural resources. The need to use energy and 

other resources more efficiently spurs the development of less carbon-intensive 

technology in some regions. Uses the CGCM2 climate model (Canadian Centre for 

Climate Modelling and Analysis, n.d.a).

The tree storylines use the following scenarios:

1) C—Variations of the A1B, A2, and B2 storylines examine effects resulting from 

a continuation of the observed recent rates of forest removals due to timber 

harvesting and land use conversion from forest to another land use. These 

variations are referred to as scenarios A1B-C, A2-C, and B2-C.

2) BIO—Variations of the A1B, A2, and B2 storylines look at impacts of increased 

harvest and utilization of woody biomass for energy. They are referred to as 

scenarios A1B-BIO, A2-BIO, and B2-BIO.

3) EAB—A variation of the A2 storyline examines the potential impact of the 

continued spread of the emerald ash borer with associated mortality of all ash trees 

in the affected areas. This is referred to as scenario A2-EAB.

What we found

The anticipated decline in forest land, which totals in the hundreds of thousands 

of acres, reverses the long-term trend of increasing forest area in Indiana observed 

since the late 1930s (Fig. 108). Specifically, over the next 50 years forest land area 
132 | FUTURE FORESTS

is projected to decline from an estimated 4.7 million acres in 2010 to 4.2 million 

acres (-12 percent) in 2060 under scenario A1B-C; to 4.4 million acres (-8 percent) 

under scenario A2-C; and to 4.5 million acres (-6 percent) under scenario B2-C. The 

projected losses of forest land are still relatively small compared to the cumulative 

increase in forest area since 1938 (Smith et al. 2009). Only three scenarios are 

represented in Figure 108 as the climate model and variations on the storylines do 

not impact the area of forest land under this model. Only the storylines (developed 

around differing demographics and levels of economic activity) alter the area of forest 

land in the model. Scenarios with increasing population and economic activity have 

less forest land over the time period.

3.0

3.5

4.0

4.5

5.0

5.5

1900 1920 1940 1960 1980 2000 2020 2040 2060 2080

Forest Land Area (million acres) 

Year

Historic

A1B-C

A2-C

B2-C

Figure 108.—Past and projected forest land area by scenario, 

Indiana, 2010-2060. 

Emerald ash borer (EAB) was initially detected in Indiana on April 21, 2004. Ash 

species make up 8 percent of the total live tree volume on forest land in Indiana 

and 12 percent of the volume in the elm/ash/cottonwood forest-type group. Under 

scenario A2-EAB, ash species live volume is projected to decline from 767 million 

cubic feet in 2010 to zero cubic feet by 2030. Under scenario A2-C, ash volume is 

expected to decline from 767 million cubic feet in 2010 to 668 million cubic feet by 

2060. There is a decline in the area of the elm/ash/cottonwood forest-type group from 

2010 to 2060 under both scenario A2-C (-13 percent) and A2-EAB (-16 percent) 

(Fig. 109). The loss of the ash component in the elm/ash/cottonwood forest-type 

group in scenario A2-EAB is partially offset by increases in other associated species in 

this forest-type group. The negative impacts of EAB are more apparent in Figure 110 

where the volume under scenario A2-EAB is projected to be 7 percent less than the 

volume under scenario A2-C in 2060. 
 | 133

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

White/red/jack pine

Oak/hickory

Elm/ash/cottonwood

Maple/beech/birch

Aspen/birch

Other

Forest Land Area (million acres)

Forest-type Group

Inventory in 2010

A2-EAB in 2060

A1B-C in 2060

A2-C in 2060

B2-C in 2060

Figure 109.—Forest land area by forest-type group, Indiana, 2010 

and by scenario in 2060.

8.5

9.0

9.5

10.0

10.5

11.0

2000 2010 2020 2030 2040 2050 2060 2070

Live Tree Volume (billion ft3

)

Year

A1B-C

A1B-BIO

A2-C 

A2-BIO

B2-C 

B2-BIO

A2-EAB

Figure 110.—Past and projected live-tree volume on forest land by 

scenario, Indiana, 2010-2060. 

The scenarios with accelerated biomass removal for energy production (A1B-BIO, 

B2-BIO, and A2-BIO) have lower levels of live tree volume in 2060 than do their 

corresponding normal biomass utilization scenarios (A1B-C, B2-C, and A2-C) 

(Fig. 110), but surprisingly live tree volume on forest land in 2060 is projected to be 

less than the 2010 volume under only the A1B-BIO and A2-BIO scenarios. The area 

of forest land is expected to decrease, but the volume per acre for all but the A1B-BIO 

and A2-BIO scenarios are expected to increase as forests continue to mature. This 

trend results from the combined effects of gradually decreasing forest area and an 

aging forest resource with high volume but low net growth per acre.
134 | FUTURE FORESTS

What this means 

The projected losses of forest land are relatively small compared to the cumulative 

decrease in forest area from the early 1900s to 1968. In fact the increase in forest area 

from 1968 to 2010 is only expected to be partially offset by projected forest land area 

losses from 2010 to 2060. 

Even though live tree volume on forest land in 2060 is projected to be less than the 

2010 volume under the A1B-BIO and A2-BIO scenarios, this does not mean that 

increased utilization of biomass for energy is ill advised. Rather, forest managers 

will need to be prudent about how much biomass is utilized and how it is obtained 

and replenished. In the past 60 years, forest managers have had the luxury of rapidly 

increasing forest volume with growth greatly exceeding removals. If projections hold 

true, that may not be the case for future generations of forest managers and woodusing industries. 
 | 135

Data Sources and Techniques 

National Woodland Owner Survey

Information about family forest owners is collected annually through the U.S. Forest 

Service’s National Woodland Owner Survey (NWOS). The NWOS was designed to 

increase our understanding of owner demographics and motivation. Individuals and 

private groups identified as woodland owners by FIA are invited to participate in the 

NWOS. Each year, questionnaires are mailed to 20 percent of private owners, with 

more detailed questionnaires sent out in years that end in 2 or 7 to coincide with 

national census, inventory, and assessment programs. Data presented here are based 

on survey responses from 232 randomly selected families and individuals who own 

forest land in Indiana. For additional information about the NWOS, visit www.fia.

fs.fed.us/nwos. 

Insects and Disease

Information about the insects and diseases affecting Indiana forests was gathered 

from the U.S. Forest Service, Northeastern Area State and Private Forestry (http://

www.na.fs.fed.us), the national Forest Health Monitoring program (http://fhm.fs.fed.

us/), and the Indiana Department of Natural Resources (http://www.in.gov/dnr/

forestry/).

Timber Products Output Inventory 

This study was a cooperative effort between the Indiana Department of Natural 

Resources (INDNR) Division of Forestry and NRS-FIA. Using a questionnaire 

designed to determine the size and composition of Indiana’s forest products industry, 

its use of roundwood (round sections cut from trees), and its generation and 

disposition of wood residues, INDNR personnel contacted all primary wood-using 

mills in the State either by mail, phone calls, personal mill visits, or a combination of 

the three. Completed questionnaires were sent to NRS-FIA for editing and processing. 

As part of data editing and processing, all industrial roundwood volumes reported 

on the questionnaires were converted to standard units of measure using regional 

conversion factors.

National Land Cover Data Imagery

Derived from Landsat Thematic Mapper satellite data (30-m pixel), the National Land 

Cover Dataset (NLCD) is a land cover classification scheme (21 classes) applied across 
136 | DATA SOURCES AND TECHNIQUES

the United States by the U.S. Geological Survey (USGS) and the U.S. Environmental 

Protection Agency (EPA). The NLCD was developed from data acquired by the 

Multi-Resolution Land Characteristics (MRLC) Consortium, a partnership of Federal 

agencies that produce or use land-cover data. Partners include the USGS, EPA, U.S. 

Forest Service, and National Oceanic and Atmospheric Administration.

Mapping Procedures

A geographic information system (GIS) and various geospatial datasets were used 

to generate the maps in this report. Unless otherwise indicated, forest resource data 

are from FIA and base map layers, e.g., state and county boundaries were obtained 

from the National Map (U.S. Geologic Survey, n.d.). Depicted FIA plot locations 

are approximate. Sources of other geospatial datasets are cited within individual 

figures. Maps in this report were constructed using (1) categorical coloring of Indiana 

counties and units according to forest attributes (such as forest land area), (2) a 

variation of the k-nearest-neighbor (KNN) technique to apply information from 

forest inventory plots to remotely sensed MODIS imagery (250 m pixel size) based 

on the spectral characterization of pixels and additional geospatial information 

(Wilson et al. 2012), or (3) colored dots to represent plot attributes at approximate 

plot locations. Most Indiana maps are portrayed in the Universal Transverse Mercator 

Coordinate System, Zone 16N, North American Datum of 1983.

Sources for Additional Information 

Detailed information on forest inventory methods, data quality estimates, important 

resource statistics, and a glossary of terms can be found in Statistics, Methods, and 

Quality Assurance which is available online at http://dx.doi.org/10.2737/NRS-RB-107. 

Data used in this report are accessible through the included software Evalidator 

(requires Microsoft Access). Some graphs and tables in the printed portion of this 

report show only a sample of the prominent categories and values available for 

summarizing data. Tables online have more categories, summary values, and custom 

tables. The main Web page for FIA is at http://www.fia.fs.fed.us/, and additional 

resources, including publications (http://www.nrs.fs.fed.us/pubs/) and data http://

apps.fs.fed.us/fiadb-downloads/datamart.html, are also available. A primary Web tool 

is FIDO or Forest Inventory Data Online (http://apps.fs.fed.us/fido/). Other tools, 

including a Web version of Evalidator, are available (http://www.fia.fs.fed.us/toolsdata/). Field guides are at http://www.fia.fs.fed.us/library/field-guides-methods-proc/. 

State-level reports are available at http://nrs.fs.fed.us/fia/data-tools/state-reports/

default.asp. In addition to FIA forest information and tools, i-Tree is a state-of-the-art, 
 | 137

peer-reviewed software suite from the U.S. Forest Service that provides urban forestry 

analysis and benefits assessment tools. The i-Tree Tools help communities of all sizes 

to strengthen their urban forest management and advocacy efforts by quantifying the 

structure of community trees and the environmental services that trees provide. Visit 

https://www.itreetools.org/ for more information. 
138 | LITERATURE CITED

Literature Cited

Abrams, M.D. 1992. Fire and the development of oak forests. BioScience. 42: 346-353. 

http://dx.doi.org/10.2307/1311781. 

Abrams, M.D. 2003. Where has all the white oak gone? BioScience. 53: 927-939. http://

dx.doi.org/10.1641/0006-3568(2003)053[0927:whatwo]2.0.co;2.

Aldrich, P.R.; Parker, G.R.; Romero-Severson, J.; Michler, C.H. 2005. Confirmation 

of oak recruitment failure in Indiana old-growth forest: 75 years of data. Forest 

Science. 51: 406-416.

Anderson, J.F.; Hardy, E.E.; Roach, J.T.; Witmer, R.E. 1976. A land use and land cover 

classification system for use with remote sensor data. U.S. Geological Survey 

Professional Paper 964. Washington, DC: U.S. Geological Survey. 28 p.

Arner, S.L.; Woudenberg, S.; Waters, S.; Vissage, J.; MacLean, C.; Thompson, M.; 

Hansen, M. 2003 (revised). National algorithms for determining stocking 

class, stand size class, and forest type for Forest Inventory and Analysis plots. 

Washington, DC: U.S. Department of Agriculture, Forest Service, Forest Inventory 

and Analysis. 65 p. Available at http://www.fia.fs.fed.us/library/sampling/index.php

(accessed August 9, 2013).

Bat Conservation International. 2014 (revised). White-nose syndrome: a crisis for 

America’s bats. Austin, TX: Bat Conservation International. 2 p. http://www.batcon.

org/pdfs/whitenose/WNS_FAQ.pdf (accessed July 16, 2015).

Bechtold, W.A.; Patterson, P.L., eds. 2005. The enhanced Forest Inventory and Analysis 

program—national sampling design and estimation procedures. Gen. Tech. Rep. 

SRS-80. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern 

Research Station. 85 p.

Brand, G.J.; Nelson, M.D.; Wendt, D.G.; Nimerfro, K.K. 2000. The hexagon/panel 

system for selecting FIA plots under an annual inventory. In: McRoberts, R.E.; 

Reams, G.A.; Van Deusen, P.C., eds. Proceedings of the first annual Forest Inventory 

and Analysis symposium. Gen. Tech. Rep. NC-213. St. Paul, MN: U.S. Department of 

Agriculture, Forest Service, North Central Research Station: 8-13.

Brose, P.H.; Gottschalk, K.W.; Horsley, S.P.; Knopp, P.D.; Kochendorfer, J.N.; 

McGuiness, B.J.; Miller, G.W.; Ristau, T.E.; Stoleson, S.H.; Stout, S.L. 2008. Prescribing 

regeneration treatments for mixed-oak forests of the mid-Atlantic region. Gen. 

Tech. Rep. NRS-33. Newtown Square, PA: U.S. Department of Agriculture, Forest 

Service, Northern Research Station. 100 p. http://dx.doi.org/10.2737/NRS-GTR-33.
 | 139

Burns, R.M.; Honkala, B.H., tech. coords. 1990. Silvics of North America: Volume 

1. Conifers. Agricultural Handbook 654. Washington, DC: U.S. Department of 

Agriculture, Forest Service. 675 p.

Burns, R.M.; Honkala, B.H., tech. coords. 1990. Silvics of North America: Volume 2. 

Hardwoods. Agricultural Handbook 654. Washington, DC: U.S. Department of 

Agriculture, Forest Service. 877 p.

Butler, B.J. 2008. Family forest owners of the United States, 2006. Gen. Tech. Rep. NRS27. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern 

Research Station. 72 p. http://dx.doi.org/10.2737/NRS-GTR-27. 

Canadian Centre for Climate Modelling and Analysis. [N.d.a]. CGCM2-coupled global 

climate model, medium resolution (T47). Ottawa, ON, Canada: Environment 

Canada. Available at http://www.cccma.ec.gc.ca/models/cgcm2.shtml (accessed July 

27, 2012).

Canadian Centre for Climate Modelling and Analysis.[N.d.b]. CGCM3.1-coupled 

global climate model (CGCM3), medium resolution (T47). Ottawa, ON, Canada: 

Environment Canada. Available at http://www.cccma.ec.gc.ca/models/cgcm3.shtml

(accessed July 27, 2012).

Carman, S.F. 2013. Indiana forest management history and practices. In: Swihart, R.K.; 

Saunders, M.R.; Kalb, R.A.; Haulton, G.S.; Michler, C.H., eds. 2013. The hardwood 

ecosystem experiment: a framework for studying responses to forest management. 

Gen. Tech. Rep. NRS-P-108. Newtown Square, PA: U.S. Department of Agriculture, 

Forest Service, Northern Research Station: 12-23. 

Cassens, D. 2001. Log and tree scaling techniques. Forestry and Natural Resources 

paper FNR-191. West Lafayette, IN: Purdue University Cooperative Extension 

Service.16 p. https://www.extension.purdue.edu/extmedia/FNR/FNR-191.pdf

(accessed April 3, 2015).

Charry, B. 2007. Conserving wildlife on and around Maine’s roads. Augusta, ME: 

Beginning with Habitat, Maine Audubon, and Maine Department of Transportation.

10 p. http://www.beginningwithhabitat.org/pdf/MARoadsWildlife-FINAL.pdf

(accessed March 23, 2015).

Conservation Biology Institute. 2012. Protected areas database of the United States. 

PAD-US 1.1 (CBI edition). Corvallis, OR. Available at http://consbio.org/products/

projects/pad-us-cbi-edition (accessed June 14, 2012). 

Dey, D.C.; Royo, A.A.; Brose, P.H.; Hutchinson, T.F.; Spetich, M.A.; Stoleson, S.H. 2010. 

An ecologically based approach to oak silviculture: a synthesis of 50 years of oak 

ecosystem research in North America. Revista Columbia Forestal. 13(2): 201-222.
140 | LITERATURE CITED

DenUyl, D. 1953. Indiana’s old growth forests. Proceedings of the Indiana Academy of 

Science. 63: 73-79. 

Donovan, T.M.; Lamberson, R.H. 2001. Area-sensitive distributions counteract 

negative effects of habitat fragmentation on breeding birds. Ecology. 82(4): 1170-

1179. http://dx.doi.org/10.2307/2679912. 

Fan, Z.; Shifley, S.R.; Spetich, M.A.; Thompson, F.R., III.; Larsen, D.R. 2003.

Distribution of cavity trees in midwestern old-growth and second-growth forests. 

Canadian Journal of Forest Research. 33: 1481-1494. http://dx.doi.org/10.1139/x03-

068. 

Forman, R.T.T.; Godron, M. 1986. Landscape ecology. New York, NY: John Wiley & 

Sons, Inc. 619 p. ISBN: 9780471870371.

Forman, R.T.T.; Sperling, D.; Bissonette, J.A.; Clevenger, A.P.; Cutshall, C.D.; Dale, V.H.; 

Fahrig, L.; France, R.L.; Goldman, C.R.; Heanue, K.; Jones, J.; Swanson, F.; Turrentine, 

T.; Winter, T.C. 2003. Road ecology: science and solutions. Washington, DC: Island 

Press. 504 p. ISBN: 9781559639330.

Fralish, J.S. 2004. The keystone role of oak and hickory in the central hardwood forest. 

In: Spetich, M.A., ed. Upland oak ecology symposium: history, current conditions, 

and sustainability. Gen. Tech. Rep. SRS-73. Asheville, NC: U.S. Department of 

Agriculture, Forest Service, Southern Research Station: 78-97.

Fry, J.; Xian, G.; Jin, S.; Dewitz, J.; Homer, C.; Yang, L.; Barnes, C.; Herold, N.; 

Wickham, J. 2011. Completion of the 2006 National Land Cover Database for the 

conterminous United States. Photogrammetric Engineering and Remote Sensing. 

77(9): 858-864.

Greenberg, C.H.; Collins, B.S.; Thompson, F.R., III, eds. 2011. Sustaining young forest 

communities: ecology and management of early successional habitat in the central 

hardwood region, USA. Managing forest ecosystems, Volume 21. New York, NY: 

Springer. 310 p. ISBN: 9789400716209.

Gremillion-Smith, C., coord. 2005. Indiana comprehensive wildlife strategy. 

Developed for Indiana Department of Natural Resources, Division of Fish and 

Wildlife. Mishawaka, IN: D.J. Case and Associates. 154 p. http://www.in.gov/dnr/

fishwild/files/CWS_MANUSCRIPT.pdf (accessed March 23, 2015).

Hahn, J.T. 1984. Tree volume and biomass equations for the Lake States. Res. Pap. 

NC-250. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central 

Forest Experiment Station. 10 p.

Hahn, J.T.; Hansen, M.H. 1991. Cubic and board foot volume models for the central 

states. Northern Journal of Applied Forestry. 8: 47-57.
 | 141

Hammer, R.B.; Stewart, S.I.; Winkler, R.L.; Radeloff, V.C.; Voss, P.R. 2004. 

Characterizing dynamic spatial and temporal residential density patterns from 

1940-1990 across the north central United States. Landscape and Urban Planning. 

69: 183-199. http://dx.doi.org/10.1016/j.landurbplan.2003.08.011. 

Hawbaker, T.J.; Radeloff, V.C. 2004. Roads and landscape pattern in northern 

Wisconsin based on a comparison of four road data sources. Conservation Biology. 

18(5): 1233-1244. http://dx.doi.org/10.1111/j.1523-1739.2004.00231.x. 

Herms, D.A.; McCullough, D.G. 2014. Emerald ash borer invasion of North America: 

history, biology, ecology, impacts and management. Annual Review of Entomology. 

59: 13-30. http://dx.doi.org/10.1146/annurev-ento-011613-162051. 

Hicks, R.R., Jr. 1998. Ecology and management of central hardwood forests. New York, 

NY: John Wiley & Sons, Inc. ISBN: 9780471137580.

Holt, H.A.; Fischer, B.C. 1979. An overview of oak regeneration problems. In: Holt, 

H.A.; Fischer, B.C., eds. Proceedings of regenerating oaks in upland hardwood forests: 

the 1979 John S. Wright Forestry Conference; February 22-23, 1979. West Lafayette, 

IN: Purdue University, Purdue Research Foundation. 132 p.

Homer, C.; Dewitz, J.; Fry, J.; Coan, M.; Hossain, N.; Larson, C.; Herold, N.; McKerrow, 

A.; VanDriel, I., Wickham, J. 2007. Completion of the 2001 National Land Cover 

Database for the conterminous United States. Photogrammetric Engineering and 

Remote Sensing. 73(4): 337-341.

Honnay, O.; Jacquemyn, H.; Bossuyt, B.; Hermy, M. 2005. Forest fragmentation effects 

on patch occupancy and population viability of herbaceous plant species. New 

Phytologist. 166: 723-736. http://dx.doi.org/10.1111/j.1469-8137.2005.01352.x. 

Huang, C.; Yang, B.; Wylie, B.; Homer, C. 2001. A strategy for estimating tree canopy 

density using Landsat 7 ETM+ and high resolution images over large areas.

In: Third international conference on geospatial information in agriculture and 

forestry; November 5-7, 2001; Denver, CO: U.S. Department of Interior, Geological 

Survey. [CD].

Hunter, W.C.; Buehler, D.A.; Canterbury, R.A.; Confer, J.L.; Hamel, P.B. 2001. 

Conservation of disturbance-dependent birds in eastern North America. Wildlife 

Society Bulletin. 29(2): 440-455.

Indiana Department of Natural Resources. 2008. Indiana state forests: environmental 

assessment 2008-2027. Indianapolis, IN: Indiana Department of Natural Resources, 

Division of Forestry. 176 p. http://www.in.gov/dnr/forestry/files/fo-StateForests_

EA.pdf (accessed June 25, 2015).
142 | LITERATURE CITED

Indiana Department of Natural Resources and Indiana Division of Fish and Wildlife 

[IDNR and IFW]. [N.d.]. Indiana’s state wildlife action plan: forests habitat summary. 

http://www.in.gov/dnr/fishwild/files/SWAP/SWAPHabitatSummary_Forests.pdf

(accessed March 23, 2015).

Indiana Natural Heritage Data Center, creator. 2015. MANAGED_LANDS_IDNR_IN: 

Managed Lands in Indiana (Indiana Department of Natural Resources, 1:24,000, 

Polygon Shapefile). Indianapolis, IN: Indiana Department of Natural Resources, 

Indiana Natural Heritage Data Center. Available at http://maps.indiana.edu/

layerGallery.html?category=ManagedLands (accessed January 2015).

Iverson, L.R., Prasad, A.N. 1998. Predicting abundance of 80 tree species following 

climate change in the eastern United States. Ecological Monographs. 68(4): 465-485. 

http://dx.doi.org/10.1890/0012-9615(1998)068[0465:paotsf]2.0.co;2. 

Jenkins, J.C.; Chojnacky, D.C.; Heath, L.S; Birdsey, R.A. 2004. Comprehensive database 

of diameter-based biomass regressions for North American tree species. Gen. Tech. 

Rep. NE-319. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, 

Northern Research Station. 45 p. http://dx.doi.org/10.2737/NE-GTR-319.

Jenkins, M.A. 2013. The history of human disturbance in forest ecosystems of southern 

Indiana. In: Swihart, R.K.; Saunders, M.R.; Kalb, R.A.; Haulton, G.S.; Michler, C.H., 

eds. The hardwood ecosystem experiment: a framework for studying responses 

to forest management. Gen. Tech. Rep. NRS-P-108. Newtown Square, PA: U.S. 

Department of Agriculture, Forest Service, Northern Research Station: 2-11. 

Jin, S.; Yang, L.; Danielson, P.; Homer, C.; Fry, J.; Xian, G. 2013. A comprehensive 

change detection method for updating the National Land Cover Database to circa 

2011. Remote Sensing of Environment. 132: 159-175. http://dx.doi.org/10.1016/j.

rse.2013.01.012. 

Johnson, P.S.; Shifley, S.R.; Rogers, R. 2002. The ecology and silviculture of oaks. New 

York, NY: CABI Publishing. ISBN: 9781845934743.

Kapos, V.; Lysenko, I.; Lesslie, R. 2000. Assessing forest integrity and naturalness in 

relation to biodiversity. Forest Resources Assessment Programme, Working Paper 

54. Rome, Italy: Food and Agriculture Organization of the United Nations, Forestry 

Department. 65 p.

King, A.R. 2006. Biological opinion for the federally endangered Indiana bat (Myotis 

sodalis) for the Hoosier National Forest’s proposed Tell City windthrow 2004 

salvage timber harvest on the Tell City ranger district, Crawford and Perry counties, 

Indiana. Bloomington, IN: U.S. Fish and Wildlife Service. 56 p. http://www.fws.gov/

midwest/endangered/mammals/inba/bos/06_IN_HNFWindThrow.pdf (accessed 

February 14, 2014).
 | 143

Kline, J.D.; Azuma, D.L.; Alig, R.J. 2004. Population growth, urban expansion, and 

private forestry in Western Oregon. Forest Science. 50(1): 33-43.

Kurtz, C.M. 2013. An assessment of invasive plant species monitored by the Northern 

Research Station Forest Inventory and Analysis program, 2005 through 2010. Gen. 

Tech. Rep. NRS-109. Newtown Square, PA: U.S. Department of Agriculture, Forest 

Service, Northern Research Station. 70 p. http://dx.doi.org/10.2737/NRS-GTR-109.

Langford, W.T.; Gergel, S.E.; Dietterich, T.G.; Cohen, W. 2006. Map misclassification 

can cause large errors in landscape pattern indices: examples from habitat 

fragmentation. Ecosystems. 9: 474-488. http://dx.doi.org/10.1007/s10021-005-0119-1. 

Lepczyk, C.A.; Hammer, R.B.; Stewart, S.I.; Radeloff, V.C. 2007. Spatiotemporal 

dynamics of housing growth hotspots in the North Central U.S. from 1940 to 2000. 

Landscape Ecology. 22: 939-952. http://dx.doi.org/10.1007/s10980-006-9066-2. 

Liebhold, A.M.; MacDonald, W.L.; Bergdahl, D.; Mastro, V.C. 1995. Invasion by exotic 

forest pests: a threat to forest ecosystems. Forest Science Monograph. 30: 1-49.

Lindsey, A.A. 1997. Walking in wilderness. In: Jackson, M.T., ed. 1997. The Natural 

Heritage of Indiana. Bloomington, IN: Indiana University Press: 113-123.

Loeb, S.C; O’Keefe, J.M. 2006. Habitat use by forest bats in South Carolina in relation 

to local, stand, and landscape characteristics. The Journal of Wildlife Management. 

70(5): 1210-1218. http://dx.doi.org/10.2193/0022-541x(2006)70[1210:hubfbi]2.0.co;2. 

Lorimer, C.G. 1993. Causes of the oak regeneration problem. In: Loftis, D.L.; 

McGee, C.E., eds. Oak regeneration: serious problems, practical recommendations 

(symposium proceedings). Gen.Tech. Rep. SE-84. Asheville, NC: U.S. Department of 

Agriculture, Forest Service, Southeastern Forest Experiment Station: 14-39.

Luensmann, P.S. 2005. Myotis sodalis. In: Fire effects information system [Online]. 

Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain 

Research Station, Fire Sciences Laboratory (Producer). http://www.fs.fed.us/database/

feis/animals/mammal/myso/all.html (accessed July 19, 2015). 

Marshall, P.T. 2012. 2011 Indiana forest health highlights. Indianapolis, IN: Indiana 

Department of Natural Resources, Division of Forestry. 11 p. http://www.fs.fed.us/

foresthealth/fhm/fhh/fhh_11/IN_FHH_2011.pdf (accessed April 10, 2015). 

McCune, B.; Cottam, G. 1985. The successional status of a southern Wisconsin oak 

woods. Ecology. 66(4): 1270-1278. http://dx.doi.org/10.2307/1939180. 

McMahon, G.; Cuffney, T.F. 2000. Quantifying urban intensity in drainage basins for 

assessing stream ecological conditions. Journal of the American Water Resources 

Association. 36(6): 1247-1261. http://dx.doi.org/10.1111/j.1752-1688.2000.tb05724.x. 
144 | LITERATURE CITED

McRoberts, R.E. 1999. Joint annual forest inventory and monitoring system: the North 

Central perspective. Journal of Forestry. 97: 21-26.

McRoberts, R.E. 2005. The enhanced Forest Inventory and Analysis program. In: 

Bechtold, W.A.; Patterson, P.L., eds. The enhanced Forest Inventory and Analysis 

program—national sampling design and estimation procedures. Gen. Tech. Rep. SRS80. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research 

Station: 1-10.

McShea, W.J.; Healy, W.M.; Devers, P.; Fearer, T.; Koch, F.H.; Stauffer, D.; Waldon, J. 2007. 

Forestry matters: decline of oaks will impact wildlife in hardwood forests. Journal of 

Wildlife Management. 71(5): 1717-1728. http://dx.doi.org/10.2193/2006-169. 

McWilliams, W.H.; Westfall, J.A.; Brose, P.H.; Dey, D.C.; Hatfield, M.; Johnson, K.; 

Laustsen, K.M.; Lehman, S.L.; Morin, R.S.; Nelson, M.D.; Ristau, T.E.; Royo, A.A.; 

Stout, S.L.; Willard, T; Woodall, C.W. 2015. A regeneration indicator for Forest 

Inventory and Analysis: history, sampling, estimation, analytics, and potential use 

in the midwest and northeast United States. Gen. Tech. Rep. NRS-148. Newtown 

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

Station. 74 p. http://dx.doi.org/10.2737/NRS-GTR-148.

Menzel, M.A.; Menzel, J.M.; Carter, T.C.; Ford, W.M.; Edwards, J. 2001. Review of the 

forest habitat relationships of the Indiana bat (Myotis sodalis). Gen. Tech. Rep. 

NE-284. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, 

Northeastern Research Station. 21 p. http://dx.doi.org/10.2737/NE-GTR-284.

Montreal Process. 1995. Criteria and indicators for the conservation and sustainable 

management of temperate and boreal forests. Hull, Quebec: Canadian Forest 

Service. 27 p.

Moody, A.; Woodcock, C.E. 1995. The influence of scale and the spatial characteristics 

of landscapes on land-cover mapping using remote sensing. Landscape Ecology. 

10(6): 363-379. http://dx.doi.org/10.1007/bf00130213. 

Morin, R.S.; Steinman, J.; Randolph, K.C. 2012. Utility of tree crown condition 

indicators to predict tree survival using remeasured Forest Inventory and Analysis 

data. In: Morin, R.S.; Liknes, G.C., comps. Moving from status to trends: Forest 

Inventory and Analysis (FIA) symposium 2012. Gen. Tech. Rep. NRS-P-105. 

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

Research Station: 210-215. [CD-ROM].

National Agriculture Statistics Service [NASS]. 2014. Statistics by state: Indiana. 

Washington, DC: Department of Agriculture, National Agricultural Statistics 

Service. Available at http://www.nass.usda.gov/Statistics_by_State/Indiana/ (accessed 

December 2014).
 | 145

National Centers for Environmental Information [NCEI]. 2015. Climate at a glance. 

Available at http://www.ncdc.noaa.gov/cag/time-series/us (accessed April 2015).

NatureServe. [N.d.]. Explorer® online encyclopedia of life. Arlington, VA: NatureServe. 

http://explorer.natureserve.org/servlet/NatureServe?init=Species (accessed February 

17, 2011).

Nowak, D.J.; Walton, J.T. 2005. Projected urban growth and its estimated impact on 

the US Forest resource (2000-2050). Journal of Forestry. 103(8): 383-389.

Nyland, R.D. 2002. Silviculture: concepts and applications. 2nd ed. Long Grove, IL: 

Waveland Press, Inc. 682 p. ISBN: 978-1577665274.

O’Connell, B.M.; LaPoint, E.B.; Turner, J.A.; Ridley, T.; Pugh, S.A.; Wilson, A.M.; 

Waddell, K.L.; Conkling, B.L. 2014. The forest inventory and analysis database: 

database description and user guide version 6.0.1 for P2. U.S. Department of 

Agriculture, Forest Service. 748 p. [Online]. Available at http://www.fia.fs.fed.us/

library/database‐documentation/.

Orwig, D.A.; Abrams, M.D. 1997. Variation in radial growth responses to drought 

among species, site, and canopy strata. Trees. 11: 474-484. http://dx.doi.org/10.1007/

s004680050110. 

Ostfeld, R.S., Jones, C.G.; Wolff, J.O. 1996. Of mice and mast, ecological connections in 

eastern deciduous forests. Bioscience. 46: 323-330. http://dx.doi.org/10.2307/1312946. 

Parker, G.R.; Ruffner, C.M. 2004. Current and historical forest conditions in the 

Hoosier-Shawnee ecological assessment area. In: Thompson, F.R., III, ed. The 

Hoosier-Shawnee ecological assessment. Gen.Tech. Rep. NC-244. St. Paul, MN: U.S. 

Department of Agriculture, Forest Service, North Central Research Station: 23-58.

Pimentel, D.; Lach, L.; Zuniga, R.; Morrison, D. 2000. Environmental and economic 

costs of nonindigenous species in the United States. BioScience. 50(1): 53-65. http://

dx.doi.org/10.1641/0006-3568(2000)050[0053:eaecon]2.3.co;2. 

Piva, R.J.; Gallion, J. 2007. Indiana timber industry—an assessment of timber product 

output and use, 2005. Resour. Bull. NRS-22. Newtown Square, PA: U.S. Department 

of Agriculture, Forest Service, Northern Research Station. 106 p. http://dx.doi.

org/10.2737/NRS-RB-22.

Poland, T.M.; McCullough, D.G. 2006. Emerald ash borer: invasion of the urban forest 

and the threat to North America’s ash resource. Journal of Forestry. 104(3): 118-124.

Potzger, J.E.; Potzger, M.E.; McCormick, J. 1956. The forest primeval of Indiana 

as recorded in the original U.S. land surveys and an evaluation of previous 

interpretations of Indiana vegetation. Butler University Botanical Studies. 13: Article 

12. http://digitalcommons.butler.edu/botanical/vol13/iss1/12.
146 | LITERATURE CITED

Pruitt, L.; TeWinkel, L., ed. 2007. Indiana bat (Myotis sodalis) draft recovery plan: first 

revision. Fort Snelling, MN: Department of the Interior, U.S. Fish and Wildlife Service, 

Region 3. 260 p. http://www.fws.gov/midwest/Endangered/mammals/inba/pdf/inba_

fnldrftrecpln_apr07.pdf (accessed June 17, 2015).

Pruitt, S.E. 2001. Biological opinion on the land and resource management plan: 

Hooiser National Forest, Indiana. Bloomington, IN: U.S. Fish and Wildlife Service. 

23 p. https://view.officeapps.live.com/op/view.aspx?src=http%3A%2F%2Fwww.

fws.gov%2Fmidwest%2FEndangered%2Fmammals%2Finba%2Fbos%2F01_IN_

HoosierLRMP.doc (accessed April 2015).

Pruitt, S.E; King, A. 2013. Conserving federally endangered Indiana bats on private 

woodlands. Indiana Woodland Steward. 22(1): 11-12. http://www.inwoodlands.org/

conserving-federally-endangere/ (accessed December 2014).

Radeloff, V.C.; Hammer, R.B.; Stewart, S.I.; Fried, J.S.; Holcomb, S.S.; McKeefry, J.F. 2005. 

The wildland urban interface in the United States. Ecological Applications. 15: 799-

805. http://dx.doi.org/10.1890/04-1413. 

Raile, G.K. 1982. Estimating stump volume. Res. Pap. NC-224. St. Paul, MN: U.S. 

Department of Agriculture, Forest Service, North Central Forest Experiment Station. 4 p.

Rathfon, R.; Farlee, L. 2002. A landowner’s guide to sustainable forestry in Indiana: Part 

3— keeping the forest healthy and productive. Forestry and National Resources paper 

FNR-182. West Lafayette, IN: Purdue University Cooperative Extension Service. 12 

p. https://www.extension.purdue.edu/extmedia/fnr/fnr-182.pdf (accessed December 

2014).

Riitters, K.H.; Wickham, J.D. 2003. How far to the nearest road? Frontiers in 

Ecology and the Environment. 1(3): 125-129. http://dx.doi.org/10.1890/1540-

9295(2003)001[0125:hfttnr]2.0.co;2. 

Riva-Murray, K.; Riemann, R.; Murdoch, P.; Fischer, J.M.; Brightbill, R.A. 2010. 

Landscape characteristics affecting streams in urbanizing regions of the Delaware 

River Basin (New Jersey, New York, and Pennsylvania, U.S.). Landscape Ecology. 

25(10): 1489-1503. http://dx.doi.org/10.1007/s10980-010-9513-y.

Rodewald, A.D. 2003. Decline of oak forests and implications for forest wildlife 

conservation. Natural Areas Journal. 23: 368-371. http://dx.doi.org/10.1007/s10980-

010-9513-y. 

Romme, R.C.; Tyrell, K.; Brack, V., Jr. 1995. Literature summary and habitat suitability 

index model: components of summer habitat for the Indiana bat, Myotis sodalis.

18 p. Unpublished report. On file with: Indiana Department of Natural Resources, 

Division of Wildlife, Bloomington, IN. 18 p.
 | 147

Rosenberg, K.V.; Rohrbaugh, R.W., Jr; Barker, S.E.; Lowe, J.D.; Hames, R.S.; Dhondt, 

A.A. 1999. A land manager’s guide to improving habitat for scarlet tanagers and 

other forest-interior birds. Ithaca, NY: The Cornell Lab of Ornithology. 

Russell, M.B.; Woodall, C.W.; D’Amato, A.W.; Fraver, S.; Bradford, J.B. 2014a. Linking 

climate change and downed woody debris decomposition across forests of the 

eastern United States. Biogeosciences. 11: 6417-6425. http://dx.doi.org/10.5194/bg11-6417-2014.

Russell, M.B.; Woodall, C.W.; Fraver, S.; D’Amato, A.W.; Domke; G.M.; Skog, K.E. 

2014b. Residence time and rate of decay for downed woody debris biomass/carbon 

in eastern US forests. Ecosystems. 17: 765-777. http://dx.doi.org/10.1007/s10021-

014-9757-5. 

Schmidt, T.L.; Hansen, M.H.; Solomakos, J.A. 2000. Indiana’s forests in 1998. Resour. 

Bull. NC-196. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North 

Central Research Station. 139 p. http://dx.doi.org/10.2737/NC-RB-196.

Schreuder, H.T.; Ernst, R.; Ramirez-Maldonado, H. 2004. Statistical techniques for 

sampling and monitoring natural resources. Gen. Tech. Rep. RMRS-GTR-126. 

Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain 

Research Station. 111 p.

Schreuder, H.T.; Gregoire, T.G.; Wood, G.B. 1993. Sampling methods for multiresource 

forest inventory. New York, NY: John Wiley & Sons, Inc. 446 p. ISBN: 978-0-471-

55245-1.

Seilheimer, T.S.; Zimmerman, P.L.; Stueve, K.M.; Perry, C.H. 2013. Landscape-scale 

modeling of water quality in Lake Superior and Lake Michigan watersheds: How 

useful are forest-based indicators? Journal of Great Lakes Research. 39(2): 211-223. 

http://dx.doi.org/10.1016/j.jglr.2013.03.012. 

Shao, G.; Wu, J. 2008. On the accuracy of landscape pattern analysis using remote 

sensing data. Landscape Ecology. 23(5): 505-511. http://dx.doi.org/10.1007/s10980-

008-9215-x. 

Shifley, S.R.; Moser, W.K., eds. 2016. Future forests of the northern United States. Gen. 

Tech. Rep. NRS-151. Newtown Square, PA: U.S. Department of Agriculture, Forest 

Service, Northern Research Station. 388 p.

Shifley, S.R.; Woodall, C.W. 2007. The past, present, and future of Indiana’s oak forests. 

In: Buckley, D.S.; Clatterbuck, W.K., eds. 2007. Proceedings, 15th Central Hardwood 

Forest conference. e-Gen. Tech. Rep. SRS–101. Asheville, NC: U.S. Department of 

Agriculture, Forest Service, Southern Research Station: 295-304.
148 | LITERATURE CITED

Smith, D.M.; Larson, B.C.; Kelty, M.J.; Ashton, P.M.S. 1997. The practice of silviculture: 

applied forest ecology. 9th ed. New York, NY: John Wiley & Sons, Inc. 537 p. ISBN: 

9780471109419.

Smith, J.E.; Heath, L.S.; Skog, K.E.; Birdsey, R.A. 2006. Methods for calculating forest 

ecosystem and harvested carbon with standard estimates for forest types of the 

United States. Gen. Tech. Rep. NE-343. Newtown Square, PA: U.S. Department 

of Agriculture, Forest Service, Northeastern Research Station. 216 p. http://dx.doi.

org/10.2737/NE-GTR-343.

Smith, W.B. 1991. Assessing removals for North Central forest inventories. Res. Pap. 

NC-299. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central 

Forest Experiment Station. 48 p.

Smith, W.B; Golitz, F.M. 1988. Indiana forest statistics. Resour. Bull. NC-108. St. Paul, 

MN: U.S. Dept. of Agriculture, Forest Service, North Central Forest Experiment 

Station. 145 p.

Smith, W.B., tech. coord.; Miles, P.D., data coord.; Perry, C.H., map coord.; Pugh, 

S.A., data CD coord. 2009. Forest resources of the United States, 2007. Gen. Tech. 

Rep. WO-78. Washington, DC: U.S. Department of Agriculture, Forest Service, 

Washington Office. 336 p.

Society of American Foresters. 1998. The dictionary of forestry. Bethesda, MD: Society 

of American Foresters. www.dictionaryofforestry.org (accessed February 9, 2012).

Spencer, J.S., Jr. 1969. Indiana’s timber. Resour. Bull. NC-7. St. Paul, MN: U.S. Department 

of Agriculture, Forest Service, North Central Forest Experiment Station. 61 p.

Spencer, J.S., Jr.; Kingsley, N.P.; Mayer, R.W. 1990. Indiana’s timber resource, 1986: an 

analysis. Resour. Bull. NC-113. St. Paul, MN: U.S. Department of Agriculture, Forest 

Service, North Central Forest Experiment Station. 85 p.

Stambaugh, J. 2014. Regeneration cutting on private woodlands. Indiana Woodland 

Steward. 23(2): 7-9. http://www.inwoodlands.org/regeneration-cutting-on-privat/

(accessed December 2014).

Starkey, D.A.; Oak, S.W.; Ryan, G.W.; Tainter, F.H.; Redmond, C.; Brown, H.D. 1989. 

Evaluation of oak decline area in the south. Protection Report R8 PR-17. Atlanta, 

GA: U.S. Department of Agriculture, Forest Service, Southern Region 43 p.

Steinman, J. 2000. Tracking the health of trees over time on forest health monitoring 

plots. In: Hansen, M.; Burk, T., eds. Integrated tools for natural resources inventories 

in the 21st century. Gen. Tech. Rep. NC-212. St. Paul, MN: U.S. Department of 

Agriculture, Forest Service, North Central Research Station: 334-339.

Stewart, C. 2011. Deer reproduction and localized management in Indiana. Indiana 

Woodland Steward. 20(1): 12-13. http://www.inwoodlands.org/deer-reproductionand-localize/ (accessed December 2014).
 | 149

Theobald, D.M. 2005. Landscape patterns of exurban growth in the USA from 1980 to 

2020. Ecology and Society. 10(1): 34. http://dx.doi.org/10.5751/es-01390-100132.

U.S. Census Bureau. 2000. TIGER/Line shapefiles. Washington, DC: U.S. Department 

of Commerce, Census Bureau. Available at http://www.census.gov/geo/www/tiger/

(accessed March 2006).

U.S. Census Bureau. 2010. United States Census 2010. Washington, DC: U.S. 

Department of Commerce, Bureau of the Census. http://www.census.gov/2010census/ 

(accessed January 2015). 

U.S. Census Bureau. 2015. Annual survey of manufacturers: 2013. Available at http://

www.census.gov/manufacturing/asm/index.html (accessed February 25, 2015).

U.S. Department of Agriculture, Animal and Plant Health Inspection Service [USDA 

APHIS]. 2009. Pathway assessment: Geosmithia sp. and Pityophthorus juglandis 

Blackman movement from the western into the eastern United States. Available at 

http://agriculture.mo.gov/plants/pdf/tc_pathwayanalysis.pdf (accessed January 2015). 

U.S. Department of Labor. 2015. Bureau of Labor Statistics 2013. Available at http://

www.bls.gov/data/ (accessed February 23, 2015).

U.S. Environmental Protection Agency. 2015. Inventory of U.S. greenhouse gas 

emissions and sinks: 1990–2013. Washington, DC: U.S. Environmental Protection 

Agency, Office of Atmospheric Programs. Available at http://www.epa.gov/

climatechange/ghgemissions/usinventoryreport.html (accessed January 2015).

U.S. Fish and Wildlife Service. 2012. North American bat death toll exceeds 5.5 million 

from white nose syndrome. Arlington, VA: Office of Communications. 2 p. http://

www.batcon.org/pdfs/U.S. FWS_WNS_Mortality_2012_NR_FINAL.pdf (accessed 

July 2015).

U.S. Forest Service. 1999. Wood handbook: wood as an engineering material. Gen. 

Tech. Rep. FPL-113. Madison, WI: U.S. Department of Agriculture, Forest Service, 

Forest Products Laboratory. 463 p.

U.S. Forest Service. 2007. Forest inventory and analysis national core field guide; field 

data collection procedures for P3 plots. Ver. 4.0. Washington, DC: U.S. Department 

of Agriculture, Forest Service. Available at http://www.fia.fs.fed.us/library/fieldguides-methods-proc/ (accessed April 9, 2015).

U.S. Forest Service. 2012. Forest inventory and analysis national core field guide; 

volume I: field data collection procedures for P2 plots. Ver. 6.0. Washington, DC: 

U.S. Department of Agriculture, Forest Service. Available at http://www.fia.fs.fed.us/

library/field-guides-methods-proc/ (accessed April 9, 2015).

U.S. Forest Service. 2014a. The Forest Inventory and Analysis database: database 

description and user guide version 6.0.1 for P3. 182 p. [Online]. Available at http://

www.fia.fs.fed.us/library/database‐documentation/ (accessed May 29, 2015).
150 | LITERATURE CITED

U.S. Forest Service. 2014b. Forest Inventory and Analysis national core field guide: 

Northern Research Station edition, volume I supplement—field data collection 

procedures for P2+ plots, ver. 6.0. Newtown Square, PA: U.S. Department of 

Agriculture, Forest Service.

U.S. Geologic Survey. [N.d.]. The national map. Washington, DC: U.S. Department of 

Interior, U.S. Geological Survey. http://nationalmap.gov/ (accessed June 30, 2016).

Van Lear, D.H.; Watt, J.M. 1993. The role of fire in oak regeneration. In: Loftis, D.L.; 

McGee, C.E., eds. Oak regeneration: serious problems, practical recommendations 

(symposium proceedings). Gen. Tech. Rep. SE-84. Asheville, NC: U.S. Department of 

Agriculture, Forest Service, Southeastern Forest Experiment Station: 66-78. 

Vitousek, P.M.; D’Antonio, C.M.; Loope, L.L.; Westbrooks, R. 1996. Biological invasions 

as global environmental change. American Scientist. 84: 468-478.

Wakeland, B.; Swihart, R.K. 2009. Ratings of white-tailed deer preferences for woody 

browse in Indiana. Proceedings of the Indiana Academy of Science. 118(1): 96-101.

Walters, B.F.; Settle, J.; Piva, R.J. 2012. Indiana timber industry: an assessment of timber 

product output and use, 2008. Resour. Bull. NRS-63. Newtown Square, PA: U.S. 

department of Agriculture, Forest Service, Northern Research Station. 72 p. http://

dx.doi.org/10.2737/NRS-RB-63.

Wargo, P.M.; Houston, D.R.; LaMadeleine, L.A. 1983. Oak decline. Forest Insect & Disease 

Leaflet 165. Washington, DC: U.S. Department of Agriculture, Forest Service. 8 p.

Wear, D.N.; Liu, R.; Foreman, M.J.; Sheffield, R.M. 1999. The effects of population 

growth on timber management and inventories in Virginia. Forest Ecology and 

Management. 118: 107-115. http://dx.doi.org/10.1016/s0378-1127(98)00491-5. 

Weigel, D.R.; Dey, D.C.; Kabrick, J. 2012. The 3 Ps of oak regeneration: planning, 

persistence, and patience. Indiana Woodland Steward. 21(2): 10-11. http://www.

inwoodlands.org/the-3-ps-of-oak-regeneration/ (accessed December 2014).

Wenger, K.F., ed. 1984. Forestry handbook. 2nd ed. New York, NY: John Wiley & Sons. 

1335 p. ISBN: 978-0471062271.

Whitehead, D.R. 1997. In the glacier’s wake: patterns of vegetation change following 

glaciation. In: Jackson, M.T., ed. The natural heritage of Indiana. Bloomington, IN: 

Indiana University Press: 102-109.

Widmann, R.H.; Randall, C.K.; Butler, B.J.; Domke, G.M.; Griffith, D.M.; Kurtz, 

C.M.; Moser, W.K.; Morin, R.S.; Nelson, M.D.; Riemann, R I.; Woodall, C.W. 2014.

Ohio’s Forests 2011. Resour. Bull. NRS-90. Newtown Square, PA: U.S. Department 

of Agriculture, Forest Service, Northern Research Station. 68 p. http://dx.doi.

org/10.2737/NRS-RB-90.
 | 151

Wilcox, B.A., Murphy, D.D. 1985. Conservation strategy: the effects of fragmentation 

on extinction. American Naturalist. 125: 879-887. http://dx.doi.org/10.1086/284386. 

Wilson, B.T.; Lister, A.J.; Riemann, R.I. 2012. A nearest-neighbor imputation approach 

to mapping tree species over large areas using forest inventory plots and moderate 

resolution raster data. Forest Ecology and Management. 271: 182-198. http://dx.doi.

org/10.1016/j.foreco.2012.02.002. 

Winters, R.K. 1953. Forest statistics of Indiana. Forest Survey Release 15. Delaware, 

OH: U.S. Department of Agriculture, Forest Service, Central States Forest Experiment 

Station. 36 p.

Womack, K.M.; Amelon, S.K.; Thompson, F.R. 2013. Resource selection by Indiana 

bats during maternity season. The Journal of Wildlife Management. 77(4): 707-715. 

http://dx.doi.org/10.1002/jwmg.498. 

Woodall, C.W.; Conkling, B.L.; Amacher, M.C.; Coulston, J.W.; Jovan, S.; Perry, C.H.; 

Schulz, B.; Smith, G.C.; Will-Wolf, S. 2010. The Forest Inventory and Analysis 

database version 4.0: database description and users manual for P3. Gen. Tech. 

Rep. NRS-61. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, 

Northern Research Station. 180 p. http://dx.doi.org/10.2737/NRS-GTR-61.

Woodall, C.W.; Johnson, D.; Gallion, J.; Perry, C.H.; Butler, B.J.; Piva, R.; Jepsen, E.; 

Nowak, D.; Marshall, P. 2005. Indiana’s forests, 1999-2003 Part A. Resour. Bull. NCRB-253A. St. Paul, MN: U.S. Department of Agriculture, Forest Service North Central 

Research Station. 95 p. http://dx.doi.org/10.2737/NC-RB-253.

Woodall, C.W.; Monleon, V.J. 2008. Sampling protocol, estimation, and analysis 

procedures for the down woody materials indicator of the FIA program. Gen. Tech. 

Rep. NRS-22. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, 

Northern Research Station. 68 p. http://dx.doi.org/10.2737/NRS-GTR-22.

Woodall, C.W.; Walters, B.F., Oswalt, S.N., Domke, G.M., Toney, C., Gray, A.N. 2013. 

Biomass and carbon attributes of downed woody materials in forests of the United 

States. Forest Ecology and Management. 305: 48-59. http://dx.doi.org/10.1016/j.

foreco.2013.05.030. 

Woodall, C.W.; Webb, M.N.; Wilson, B.T.; Settle, J.; Piva, R.J.; Perry, C.H.; Meneguzzo, 

D.M.; Crocker, S.J.; Butler, B.J.; Hansen, M.; Hatfield, M.; Brand, G.; Barnett, C. 2011. 

Indiana's Forests 2008. Resour. Bull. NRS-45. Newtown Square, PA: U.S. Department 

of Agriculture, Forest Service, Northern Research Station. 56 p. [CD included]. http://

dx.doi.org/10.2737/NRS-RB-45.
152 | APPENDIXES

Appendixes

Appendix 1.—Tree species observed on FIA plots, Indiana, 2013

Common name Scientific Name

Eastern redcedar Juniperus virginiana 

Tamarack (native) Larix laricina 

Norway spruce Picea abies 

Blue spruce Picea pungens 

Jack pine Pinus banksiana 

Shortleaf pine Pinus echinata 

Austrian pine Pinus nigra 

Red pine Pinus resinosa 

Eastern white pine Pinus strobus 

Scotch pine Pinus sylvestris 

Virginia pine Pinus virginiana 

Baldcypress Taxodium distichum 

Boxelder Acer negundo 

Black maple Acer nigrum 

Red maple Acer rubrum 

Silver maple Acer saccharinum 

Sugar maple Acer saccharum 

Ohio buckeye Aesculus glabra 

Ailanthus Ailanthus altissima 

European alder Alnus glutinosa 

Common serviceberry Amelanchier arborea 

Serviceberry spp. Amelanchier spp.

Pawpaw Asimina triloba 

Yellow birch Betula alleghaniensis 

River birch Betula nigra 

American hornbeam, musclewood Carpinus caroliniana 

Mockernut hickory Carya alba 

Water hickory Carya aquatica 

Bitternut hickory Carya cordiformis 

Pignut hickory Carya glabra 

Pecan Carya illinoinensis 

Shellbark hickory Carya laciniosa 

Red hickory Carya ovalis 

Shagbark hickory Carya ovata 

Northern catalpa Catalpa speciosa 

Sugarberry Celtis laevigata 

(Appendix continued on next page.)
 | 153

Common name Scientific Name

Hackberry Celtis occidentalis 

Eastern redbud Cercis canadensis 

Flowering dogwood Cornus florida 

Cockspur hawthorn Crataegus crus-galli 

Hawthorn spp. Crataegus spp.

Common persimmon Diospyros virginiana 

American beech Fagus grandifolia 

White ash Fraxinus americana 

Black ash Fraxinus nigra 

Green ash Fraxinus pennsylvanica 

Blue ash Fraxinus quadrangulata 

Honeylocust Gleditsia triacanthos 

Kentucky coffeetree Gymnocladus dioicus 

Butternut Juglans cinerea 

Black walnut Juglans nigra 

Sweetgum Liquidambar styraciflua 

Yellow-poplar Liriodendron tulipifera 

Osage-orange Maclura pomifera 

Apple spp. Malus spp.

White mulberry Morus alba 

Red mulberry Morus rubra 

Mulberry spp. Morus spp.

Blackgum Nyssa sylvatica 

Eastern hophornbeam Ostrya virginiana 

Sourwood Oxydendrum arboreum 

American sycamore Platanus occidentalis 

Eastern cottonwood Populus deltoides 

Bigtooth aspen Populus grandidentata 

Swamp cottonwood Populus heterophylla 

Quaking aspen Populus tremuloides 

American plum Prunus americana 

Black cherry Prunus serotina 

Cherry and plum spp. Prunus spp.

White oak Quercus alba 

Swamp white oak Quercus bicolor 

Scarlet oak Quercus coccinea 

Northern pin oak Quercus ellipsoidalis 

Shingle oak Quercus imbricaria 

(Appendix continued) 

(Appendix continued on next page.)
154 | APPENDIXES

Common name Scientific Name

Bur oak Quercus macrocarpa 

Blackjack oak Quercus marilandica 

Swamp chestnut oak Quercus michauxii 

Chinkapin oak Quercus muehlenbergii 

Cherrybark oak Quercus pagoda 

Pin oak Quercus palustris 

Chestnut oak Quercus prinus 

Northern red oak Quercus rubra 

Shumard oak Quercus shumardii 

Post oak Quercus stellata 

Black oak Quercus velutina 

Black locust Robinia pseudoacacia 

Black willow Salix nigra 

Willow spp. Salix spp.

Sassafras Sassafras albidum 

American basswood Tilia americana 

Winged elm Ulmus alata 

American elm Ulmus americana 

Siberian elm Ulmus pumila 

Slippery elm Ulmus rubra 

Rock elm Ulmus thomasii 

(Appendix continued) 
 | 155

Appendix 2.

Mulipliers for converting between International 1⁄4-inch rule volume and Doyle log rule volume for hardwoods and 

softwoods (modified from Smith 1991)

Tree Diameter 

2-inch class

To convert International 1⁄4-inch rule volume to 

Doyle log rule volume, mutiply by:

Hardwood Softwood

12 0.4172 0.478

14 0.5118 0.5992

16 0.5882 0.6908

18 0.6569 0.7685

20 0.718 0.8573

22 0.7829 0.8645

24 0.8324 0.9276

26 0.8736 0.9493

28 0.9473 0.971

30 + 1.1349 1.1065

* Result of multiplication will be volume in Doyle log rule.

Tree Diameter 

2-inch class

To convert Doyle log rule volume to 

International 1⁄4-inch rule volume, mutiply by:

Hardwood Softwood

10 2.8944

12 2.3969 2.0921

14 1.9539 1.6689

16 1.7001 1.4476

18 1.5223 1.3012

20 1.3928 1.1665

22 1.2773 1.1567

24 1.2013 1.0781

26 1.447 1.0534

28 1.0556 1.0299

30 + 0.8811 0.9038

* Result of multiplication will be volume in International 1⁄4-inch rule.

Mulipliers for converting between Doyle log rule volume and International 1⁄4-inch rule volume for hardwoods and 

softwoods (modified from Smith 1991)
156 | 

Fall foliage reflects in Beanblossom Lake, Morgan-Monroe State Forest. Photo by Indiana Department of Natural 

Resources, used with permission.
Gormanson, Dale D.; Gallion, Joey; Barnett, Charles J.; Butler, Brett J.; Crocker, Susan J.;

Kurtz, Cassandra M.; Lister, Tonya W.; Luppold, William; McWilliams, William; Miles, 

Patrick D.; Morin, Randall S.; Nelson, Mark D.; O’Connell, Barbara M.; Perry, Charles H.; 

Riemann, Rachel I.; Piva, Ronald J.; Smith, James E.; Sowers, Paul A.; Westfall, James 

A.; Woodall, Christopher W. 2016. Indiana Forests 2013. Resour. Bull. NRS-107. 

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

Station. 156 p.

This report summarizes the third full annualized inventory of Indiana forests conducted 

from 2009 to 2013 by the Forest Inventory and Analysis program of the Northern 

Research Station in cooperation with the Indiana Department of Natural Resources, 

Division of Forestry. Indiana has nearly 4.9 million acres of forest land with an average 

of 454 trees per acre. Forest land is dominated by the white oak/red oak/hickory forest 

type, which occupies 72 percent of the total forest land area. Most stands are dominated 

by large trees. Seventy-eight percent of forest land consists of sawtimber, 15 percent 

contains poletimber, and 7 percent contains saplings/seedlings. Growing-stock volume 

on timberland has been rising since the 1980s and currently totals 9.1 billion cubic feet. 

Annual growth outpaced removals by a ratio of 3.3:1. Additional information on forest 

attributes, changing land use patterns, timber products, and forest health is included in 

this report. Detailed information on forest inventory methods and data quality, a glossary 

of terms, tabular estimates for a variety of forest characteristics, and additional resources 

are available online at http://dx.doi.org/10.2737/NRS-RB-107.

KEY WORDS: Indiana, inventory, forest statistics, forest land, volume, biomass, riparian, 

growth, removals, mortality, forest health, forest management, bats.

In accordance with Federal civil rights law and U.S. Department of Agriculture (USDA) civil rights regulations and policies, the USDA, its 

Agencies, offices, and employees, and institutions participating in or administering USDA programs are prohibited from discriminating 

based on race, color, national origin, religion, sex, gender identity (including gender expression), sexual orientation, disability, age, 

marital status, family/parental status, income derived from a public assistance program, political beliefs, or reprisal or retaliation for 

prior civil rights activity, in any program or activity conducted or funded by USDA (not all bases apply to all programs). Remedies and 

complaint filing deadlines vary by program or incident.

Persons with disabilities who require alternative means of communication for program information (e.g., Braille, large print, audiotape, 

American Sign Language, etc.) should contact the responsible Agency or USDA’s TARGET Center at (202) 720-2600 (voice and TTY) 

or contact USDA through the Federal Relay Service at (800) 877-8339. Additionally, program information may be made available in 

languages other than English.

To file a program discrimination complaint, complete the USDA Program Discrimination Complaint Form, AD-3027, found online 

at http://www.ascr.usda.gov/complaint_filing_cust.html and at any USDA office or write a letter addressed to USDA and provide 

in the letter all of the information requested in the form. To request a copy of the complaint form, call (866) 632-9992. Submit your 

completed form or letter to USDA by: (1) mail: U.S. Department of Agriculture, Office of the Assistant Secretary for Civil Rights, 1400 

Independence Avenue, SW, Washington, D.C. 20250-9410; (2) fax: (202) 690-7442; or (3) email: program.intake@usda.gov.