Forests of the Black Hills 

National Forest 2011

Resource Bulletin

NRS-83

United States 

Department of Agriculture

Forest 

Service
Abstract

This inventory of the Black Hills National Forest (BHNF) covers the years 2007–2011 on the South Dakota portion 

of the forest and 2005 on the Wyoming portion. It reports more than 1.16 million acres of forest land dominated 

by ponderosa pine. Forest features reported on include volume, biomass, growth, removals, mortality, carbon, 

snags, and down woody material, along with information on forest economics. This report provides the public 

with a set of forest statistics that may be used in the Black Hills’ land management decisionmaking.

Acknowledgments

The authors would like to thank the many people who contributed to the inventory and analysis of the Black Hills 

National Forest. Primary field crew and Quality Assurance staff that collected field data included Bob Adams, 

Nathan Cochran, Michael Downs, Adam Felts, Thomas Goff, Tim Halberg, Brent Hummel, Dick Kessle, Mark 

Majewsky, Sheldon Murphy, Greg Pugh, Douglas Rollins, and Earl Sheehan. Reviewers of report drafts included 

Blaine Cook, Deanna Reyher, and Ed Fischer of the Black Hills National Forest.

Published by: For additional copies:

U.S. FOREST SERVICE U.S. Forest Service

11 CAMPUS BLVD., SUITE 200 Publications Distribution

NEWTOWN SQUARE, PA 19073-3294 359 Main Road

Delaware, OH 43015-8640

July 2013 Fax: 740-368-0152

Visit our homepage at: http://www.nrs.fs.fed.us

Cover: Aerial photo of the Black Hills National Forest, September 2011. Photo by Beth Doten, U.S. Forest Service, 

Black Hills National Forest.

Manuscript received for publication November 2012

Printed on recycled paper
Brian F. Walters is a forester with 

the Forest Inventory and Analysis 

(FIA) program, Northern Research 

Station, St. Paul, MN.

Christopher W. Woodall and Grant 

M. Domke are research foresters 

with FIA, Northern Research 

Station, St. Paul, MN.

Ronald J. Piva, Mark A. Hatfield, 

and David E. Haugen are foresters 

with FIA, Northern Research 

Station, St. Paul, MN.

Forests of the Black Hills 

National Forest 2011

About the Authors

Brian F. Walters, Christopher W. Woodall, Ronald J. Piva, Mark A. Hatfield, Grant M. Domke, 

and David E. Haugen

Contact author: 

Brian F. Walters, bfwalters@fs.fed.us

651-649-5135
Foreword

Understanding forest inventory is essential in building a greater understanding of complex forest 

conditions, and the interdependent plants, animals, and human uses and opportunities. This 

report, summarizing information collected through 2011, characterizes the Black Hills National 

Forest of South Dakota and Wyoming, with both quantifiable information and a basic discussion 

of what the numbers mean. Resource professionals and interested readers will benefit from this 

reliable inventory, a key milestone since the 2002 survey, for using in trend analysis, adding 

context to project planning, and aiding in future forest planning. If you enjoy learning about the 

big picture of the BHNF’s inventory, you will enjoy reading and retaining this well-done report!

Craig Bobzien, Forest Supervisor, Black Hills National Forest
Contents

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

Forest Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Forest Land Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Biomass and Volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Tree Species Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Density of Ponderosa Pine Forests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Forest Growth, Removals, and Mortality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Carbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Standing Dead Trees (Snags) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Down Woody Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Forest Economics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Growing-Stock and Sawtimber Volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Timber Products Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Data Sources and Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Forest Inventory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

A Comparison of Volume Models for Ponderosa Pine . . . . . . . . . . . . . . . . . . . . . . . . . 21

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Appendix Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
vi
1

INTRODUCTION

Aerial survey of the beetle kill in the Deefield Lake area, Mystic Ranger District of the Black Hills National Forest. 

Photo by Gary Chancey, U.S. Forest Service, Black Hills National Forest.

•	 The amount of forest land in the Black Hills National 

Forest (BHNF) is estimated at 1.16 million acres. 

•	 Ponderosa pine is the dominant forest type. 

•	 Live aboveground tree biomass is estimated to be 

30.2 million oven-dry short tons. 

•	 Eleven tree species were documented in the BHNF. 

The five most common in terms of number of trees 

were ponderosa pine (Pinus ponderosa), quaking aspen 

(Populus tremuloides), bur oak (Quercus macrocarpa), 

white spruce (Picea glauca), and paper birch (Betula 

papyifera). 

•	 Average annual net growth of ponderosa pine growing 

stock on timberland is estimated to exceed 21 million 

cubic feet/year. 

Highlights

•	 The net growth to removals ratio of ponderosa pine 

growing stock on timberland is 0.88. 

•	 The BHNF holds more than 55 million tons of 

carbon. The largest carbon stocks are in the soil 

organic matter pool. 

•	 Compared to ponderosa pine forests in neighboring 

Montana, the BHNF’s ponderosa pine forests have 

larger coarse woody debris and litter fuel loadings in 

tons per acre. 

•	 Net sawtimber volume on the BHNF is estimated at 

more than 4.98 billion board feet (Scribner rule). 

•	 In 2009, 29.3 million cubic feet of industrial 

roundwood was harvested from the BHNF and 

processed at nearby mills.
2
3

Forest Features

Aerial photo of the Black Hills National Forest, September 2011. Photo by Beth Doten, U.S. Forest Service, Black Hills National Forest.
4

FOREST FEATURES

Forest Land Area

Background

Area estimates are the most basic and frequently cited 

of all forest inventory estimates. They are essential 

in assessing the status of a region’s forest ecosystems. 

Fluctuations in forest land area estimates may indicate 

changing land use or forest health conditions, or in the 

case of a national forest, they may be the result of a land 

acquisition, sale, or swap.

What we found

The forest land area of the BHNF was estimated to be 

more than 1.16 million acres, roughly 1 percent of which 

is reserved as part of the Black Elk Wilderness Area 

(Fig. 1). The ponderosa pine forest-type group makes 

up much (~ 76 percent) of the total forest land (Fig. 2). 

The aspen/birch and spruce/fir forest-type groups, at an 

estimated 93,400 acres and 51,600 acres, respectively, are 

the only other groups on the BHNF that cover at least 

50,000 acres. The area of timberland was estimated at 

1.14 million acres. Timberland, a subset of forest land, is 

defined as forested area capable of growing a minimum 

of 20 cubic feet/acre per year (at culmination of mean 

annual increment) and is not reserved from harvest by 

law or statute, such as a wilderness area. Sawtimbersize stands dominate timberland area, covering about 

752,400 acres (Fig. 3). Although the ponderosa pine 

forest-type group makes up the overwhelming majority 

of the sawtimber- and poletimber-size stands, it is only 

50 percent of the sapling-seedling-size stands.

What this means

The 1.14 million acres of timberland represent 98 percent 

of the total forest land in the BHNF. With most of that 

area covered by stands in the large-diameter class, it has 

good prospects for potential timber production. Although 

the BHNF is known for its vast forests of ponderosa pine, 

its areas of aspen/birch, spruce/fir, and other forest-type 

groups should not be overlooked for their contributions 

to timber, wildlife habitat, and other benefits. The high 

proportion of area in the large-diameter stand class 

means the forest is mature, but the plentiful area in the 

medium and small classes signifies adequate reproduction. 

However, the high proportion of small-diameter stands 

that are in forest-type groups other than ponderosa pine 

may be of concern. Large numbers of ponderosa pines 

killed by the mountain pine beetle (MPB; Dendroctonus 

ponderosae) may be replaced by other species.

0 100 200 300 400 500 600 700 800 900 1,000 

Pinyon/juniper 

Other hardwoods 

Oak/hickory 

Spruce/fir 

Aspen/birch 

Ponderosa pine 

Area of Forest Land (thousand acres) 

Forest-type Group 

Ponderosa pine 

Other forest-type groups 

0 

100 

200 

300 

400 

500 

600 

700 

800 

900 

Sawtimber Poletimber Sapling-seedling Nonstocked 

Area of Timberland (thousand acres) 

Stand-size Class 

Figure 2.—Area of forest land by forest-type group, Black Hills National 

Forest, 2005 (Wyoming) and 2007-2011 (South Dakota). Error bars show the 68 

percent confidence interval.

Figure 3.—Area of timberland by forest-type group and stand-size class, Black 

Hills National Forest, 2005 (Wyoming) and 2007-2011 (South Dakota). Error 

bars show the 68 percent confidence interval. Note: error bars are for the total 

area of timberland in each stand-size class.
5

FOREST FEATURES

0 20 Miles

Figure 1.—Map of the Black Hills National Forest, 2005 (Wyoming) and 2007-2011 (South Dakota). Plot locations are approximate.

Black Hills National Forest Boundary

Ranger District Boundary

Black Hills National Forest Land

Black Elk Wilderness Area

Plot Location

Locator Map

Bearlodge

Ranger 

District

Northern Hills

Ranger District

Hell Canyon

Ranger

District

Mystic

Ranger

District
6

FOREST FEATURES

Biomass and Volume

Background

As with measures of the BHNF acreage, measuring total 

tree biomass and all tree volume helps us understand 

the components of a forest stand and the resources 

available for different uses (e.g., wildlife habitat, carbon 

sequestration, biofuels). Historically, volume has been 

reported as either growing stock or sawtimber, ignoring 

volume found in noncommercial, rotten, rough, or 

salvable dead trees that have potential value as wood fiber 

or fuelwood. With interest increasing in FIA data from 

an ecological perspective, a greater focus has been placed 

on all tree volume in addition to biomass.

What we found

Live aboveground tree (at least 1 inch d.b.h./d.r.c.) 

biomass on forest land was estimated at more than 

30.2 million oven-dry short tons. Softwoods made up a 

large majority of the total, 28.9 million dry short tons, 

95 percent of which is ponderosa pine (Fig. 4). Most 

of the biomass is in the boles of growing-stock trees, 

followed by growing-stock tree stumps, tops, and limbs 

and trees less than 5 inches d.b.h./d.r.c. (Fig. 5). All tree 

volume (at least 5 inches d.b.h./d.r.c.) was estimated at 

1.6 billion cubic feet, an average of 1,378 cubic feet of 

volume per acre of forest land. Ponderosa pine accounted 

for 94 percent of the total (Fig. 6). Volume from nongrowing-stock trees amounted to 127 million cubic feet, 

just under 8 percent of all tree volume (Fig. 7).

Ponderosa 

pine 

White spruce Quaking 

aspen 

Bur oak All other 

species 

Species 

1 

0

2 

3 

25 

26 

27 

28 

Live-tree Aboveground Biomass 

(million dry short tons) 

17% 

3% 4% 

75% 

1% 

Trees diameter <5 inches 

GS trees boles 

GS trees stumps, tops, 

and limbs 

Non-GS trees boles 

Non-GS trees stumps, tops, 

and limbs 

4% 1% 

94% 

1% 

Ponderosa pine 

White spruce 

Quaking aspen 

All other species 

Figure 4.—Live-tree aboveground biomass on forest land by species, Black 

Hills National Forest, 2005 (Wyoming) and 2007-2011 (South Dakota).

Figure 5.—Live-tree aboveground biomass on forest land by tree component, 

Black Hills National Forest, 2005 (Wyoming) and 2007-2011 (South Dakota). 

(Note: GS refers to growing-stock trees and non-GS refers to non-growingstock trees at least 5 inches d.b.h./d.r.c.).

Figure 6.—Net volume (thousand ft3) of all trees (at least 5 inches d.b.h./

d.r.c.) on forest land by species, Black Hills National Forest, 2005 (Wyoming) 

and 2007-2011 (South Dakota).
7

FOREST FEATURES

What this means

The total live-tree biomass on the BHNF is a 

tremendous resource both in terms of economic and 

environmental importance. The potential for expanding 

woody biomass for energy production makes knowledge 

of the resource amount vital to additional demands 

on forest planning and management. Likewise for all 

volume, while growing-stock volume is important, 

knowing how much non-growing-stock volume is in the 

BHNF potentially opens that resource to be managed for 

timber, pulp, or non-timber products.

Tree Species Composition

Background

The species composition of a forest drives the dynamics 

of its growth, development, and ecosystem function. 

Some forests are composed of a diverse set of tree species 

while others are composed of very few different species 

or dominated by a single species. Both types of forests 

provide a variety of ecological niches that various plant 

and animal communities require. Although diverse 

forests are not completely free of forest health problems, 

they are less likely to be devastated by insect or disease 

attacks than a forest composed of a single species or 

narrow group of species. The Shannon Diversity Index is 

a good measure of species diversity because it combines 

measures of the number of species present and the 

relative distribution of those species (Magurran 1988). 

Knowledge of current species compositions and diversity 

allows us to quantify the character of current and 

potential future forest ecosystems.

What we found

The BHNF contains more than 405 million trees (at 

least 1 inch d.b.h./d.r.c.) representing 11 different tree 

species that were documented during this inventory. 

Ponderosa pine was by far the most common species; 

with more than 285 million trees, it made up 70 percent 

of the total number of trees (Fig. 8). Quaking aspen 

was the next most abundant species on the forest with 

40 million trees, or about 10 percent of all trees. The 

Shannon Diversity Index value for the BHNF as a whole 

was 1.13, where a value of 0 would be no diversity (i.e., 

a single species covering the entire forest) and the value 

increases with more species present and distributed 

evenly. For reference, the Shannon Index for the 

Monongahela National Forest, containing a diverse mix 

of central Appalachian hardwoods, is 2.91. 

0 

10 

20 

30 

40 

50 

60 

70 

Salvable dead trees Rough trees Rotten trees 

Net Volume (thousand ft ) 

Non-growing-stock Sources 

American elm 

Pin cherry 

Green ash 

Serviceberry spp. 

Rocky Mountain juniper 

Eastern hophornbeam 

Paper birch 

White spruce 

Bur oak 

Quaking aspen 

Ponderosa pine 

Number of Trees (millions) 

Species 

0 25 50 250 275 300 

Figure 7.—Net volume of non-growing-stock trees (at least 5 inches 

d.b.h./d.r.c.) on forest land, Black Hills National Forest, 2005 (Wyoming) and 

2007-2011 (South Dakota).

Figure 8.—Number of live trees on forest land by species, Black Hills National 

Forest, 2005 (Wyoming) and 2007-2011 (South Dakota). Error bars show the 68 

percent confidence interval.
8

FOREST FEATURES

As elevation changes, so does the diversity of the forest 

land. Elevation is associated with variations in local 

climate, having considerable impact on the ability of 

a tree species to compete with other species. The most 

diverse range in elevation occurred at 4,000 to 4,999 

feet. The Shannon value was 1.17, and there were seven 

species present (Fig. 9). Ponderosa pine was the most 

abundant species at all elevation ranges; above 7,000 

feet, it was the only species present. Below 5,000 feet, 

bur oak was the second most abundant species present; 

above 5,000 feet, quaking aspen was the second most 

abundant species.

Density of Ponderosa Pine 

Forests

Background

The relative density of a forest indicates the current 

phase of stand development and has implications for 

diameter growth, tree mortality, and yield. Relative 

density, a measure of a forest’s current stocking of trees 

per unit area relative to a maximum, represents the 

degree of tree occupancy required to fully utilize the 

growth potential of the land. A relative density between 

0.30 and 0.60 can suggest full site occupancy, while 

relative density exceeding 0.60 often indicates imminent 

mortality. Relative density was calculated using Stand 

Density Index (Long 1985). Because the ponderosa pine 

forest type dominates much of the BHNF’s landscape, 

assessing its current level of stocking relative to its 

maximum can indicate future trajectories of stand 

development.

What we found

Most of the ponderosa pine forests of the BHNF are at 

full site occupancy (Fig. 10). Only the youngest stands 

(< 25 years in age), with relative density approximately 

0.15, are substantially below full site occupancy. There 

is no evidence of stand stocking increasing with stand 

age once stand age exceeds 25 years. In contrast to stand 

age, as ponderosa pine stands develop and more fully 

occupy BHNF sites, their gross live-tree volume nearly 

quadruples from nearly 500 cubic feet/acre in stands 

with relative density below 0.10 to nearly 4,000 cubic 

feet/acre in stands with relative density between 0.70 and 

0.80 (Fig. 11). It should be noted that the mean live-tree 

gross volume drops to nearly 3,500 cubic feet/acre at the 

highest levels of relative density.

0 0.2 0.4 0.6 0.8 1 1.2 1.4 

All elevations 

3,000 - 3,999 

4,000 - 4,999 

5,000 - 5,999 

6,000 - 6,999 

7,000 + 

Shannon Diversity Index 

Elevation (feet) 

What this means

Because ponderosa pine is the major tree species on the 

BHNF, much of the forest ecology is based around it. A 

big disadvantage to having a forest with so many trees 

from one species is susceptibility to attack by forest pests. 

That scenario has played out many times on the BHNF 

through its history with MPB outbreaks, including 

another major epidemic cycle that significantly increased 

in intensity during the mid- to late-1990s.

Figure 9.—Shannon Diversity Index by elevation, Black Hills National Forest, 

2005 (Wyoming) and 2007-2011 (South Dakota).
9

FOREST FEATURES

What this means

The dynamics between the relative density (i.e., live-tree 

stocking), stand age, and total live-tree volumes per acre 

presents evidence of a maturing forest resource across the 

BHNF. Unless disturbances (i.e., tree mortality/removal) 

occur, either human-induced or natural, it should be 

expected that this trend will continue until ponderosa 

pine stands reach a state of senescence (i.e., overstocking 

with substantial self-thinning). Although many of 

BHNF’s ponderosa pine stands have reached relative 

densities just at the minimum level of full stocking 

suggestive of minimal impending mortality, as these 

stands are fully stocked they can be more susceptible 

to the effects of droughts or MPB attacks. Compared 

to relative densities across forests of the U.S. (Woodall 

et al. 2006), the stocking of ponderosa pine forests of the 

BHNF is not excessive, although most forests in the U.S. 

do not face the same unique disturbance events (e.g., 

wildfire) as those in the BHNF.

Forest Growth, Removals, 

and Mortality

Background

Forest health, vigor, and the rate of woody biomass 

accretion and depletion are all influenced by the 

dynamic relationship between tree growth, mortality, 

and removals (i.e., harvests and land use change). 

A stand’s capacity for growth is an indication of the 

overall condition of the forest and more specifically of 

tree vigor, forest health, and successional stage. Forest 

growth is measured as average annual net growth, 

where net growth is equivalent to gross growth minus 

mortality. Mortality can be caused by insects, disease, 

adverse weather, succession, competition, fire, old age, 

or human or animal activity, and is often the result of a 

combination of these factors. Growing-stock mortality 

estimates represent the average cubic-foot volume of 

sound wood in growing-stock trees that died each year 

as an average for the years between inventories. Changes 

in the quantity of growing stock removed help identify 

trends in land use change and forest management. 

Because removals are generally recorded on a limited 

number of plots, the estimates for removals show 

greater variance than those for growth, mortality, or 

area. Because the BHNF spans two states with varying 

periodic and annual inventories, change estimation is 

based on two full cycle periodic inventories in Wyoming 

(2000 and 2005) and two full cycle annual inventories in 

South Dakota (2002-2006 and 2007-2011).

0.00 

0.05 

0.10 

0.15 

0.20 

0.25 

0.30 

0.35 

0.40 

0.45 

0-25 26-50 51-75 76-100 101-125 126-150 150+ 

Relative Density 

Stand Age (years) 

0 

500 

1,000 

1,500 

2,000 

2,500 

3,000 

3,500 

4,000 

4,500 

0.1 0.1-0.2 

0.2-0.3 

0.3-0.4 

0.4-0.5 

0.5-0.6 

0.6-0.7 

0.7-0.8 

0.8+ 

Gross Live-tree Volume (ft ) 

Relative Density 

Figure 10.—Mean relative density and associated standard errors of 

ponderosa pine forest type on forest land by classes of stand age, Black Hills 

National Forest, 2005 (Wyoming) and 2007-2011 (South Dakota) (Note: dashed 

red line indicates full site occupancy).

Figure 11.—Mean live-tree gross volume and associated standard errors of 

the ponderosa pine forest type by classes of relative density on forest land, 

Black Hills National Forest, 2005 (Wyoming) and 2007-2011 (South Dakota).
10

FOREST FEATURES

What we found

Ponderosa pine dominates the average annual net 

growth of growing stock across the BHNF, exceeding 

21 million cubic feet/year on timberland (Fig. 12). 

At a distant second place is white spruce at about 1 

million cubic feet/year. Given the fairly limited tree 

species diversity in the BHNF, no other tree species 

demonstrated appreciable growth (e.g., bur oak and 

green ash (Fraxinus pennsylvanica)). It should be noted 

that given the relatively high mortality rates of quaking 

aspen, this species had negative net average annual 

growth. Quaking aspen had average annual mortality 

exceeding that of white spruce, 970,000 versus 826,000 

cubic feet/year, respectively (Fig. 13). Ponderosa pine 

had average annual mortality at approximately 14 

million cubic feet/year, less than half of the gross growth 

within the BHNF. Removals (i.e., harvests or land use 

change) are dominated by white spruce and ponderosa 

pine on timberland in the BHNF at about 1 and 24 

million cubic feet/year, respectively (Fig. 14). The net 

growth to removals ratio of ponderosa pine of growingstock volume on timberland in the BHNF is 0.88. When 

growth/removals/mortality are viewed on a relative basis 

compared to total growing-stock volume, ponderosa 

pine trends are sustainable given the species’ tremendous 

total volume (Fig. 15). In contrast, species such as 

quaking aspen and paper birch have high mortality rates 

compared to their total volumes. Green ash and white 

spruce have the highest relative rates of growth and 

removals, respectively.

-1,000 4,000 9,000 14,000 19,000 24,000 29,000 

Ponderosa pine 

White spruce 

Bur oak 

Paper birch 

Green ash 

American elm 

Quaking aspen 

Average Annual Net Volume Growth (thousand ft /year) 

Species 

-1,000 4,000 9,000 14,000 19,000 

Ponderosa pine 

White spruce 

Bur oak 

Paper birch 

Green ash 

American elm 

Quaking aspen 

Average Annual Volume Mortality (thousand ft /year) 

Species 

Species 

-1 4 9 14 19 24 29 34 

Ponderosa pine 

White spruce 

Bur oak 

Paper birch 

Green ash 

American elm 

Quaking aspen 

Average Annual Removals (million ft /year) 

Mortality 

Removals 

Growth 

-0.05 -0.03 -0.01 0.01 0.03 0.05 0.07 0.09 0.11

Ponderosa pine 

White spruce 

Bur oak 

Paper birch 

Green ash 

American elm 

Quaking aspen 

Ratio of Average Annual Estimate 

Compared to Total Species Volume 

Species 

Figure 12.—Top species in terms of average annual net (gross growth minus 

mortality) growing-stock volume growth on timberland, Black Hills National 

Forest, 2000 to 2005 (Wyoming) and 2002-2006 to 2007-2011 (South Dakota). 

(Note: negative net growth indicates mortality exceeded gross growth). Error 

bars show the 68 percent confidence interval.

Figure 13.—Top species in terms of average annual net growing-stock volume 

mortality on timberland, Black Hills National Forest, 2000 to 2005 (Wyoming) 

and 2002-2006 to 2007-2011 (South Dakota). Error bars show the 68 percent 

confidence interval.

Figure 14.—Top species in terms of average annual net growing-stock volume 

removals per acre of timberland, Black Hills National Forest, 2000 to 2005 

(Wyoming) and 2002-2006 to 2007-2011 (South Dakota). Error bars show the 

68 percent confidence interval.

Figure 15.—Top species in terms of average annual net volume growth, 

mortality, and removals as a percent of total growing-stock volume on 

timberland, Black Hills National Forest, 2000 to 2005 (Wyoming) and 

2002-2006 to 2007-2011 (South Dakota). Error bars show the 68 percent 

confidence interval.
11

FOREST FEATURES

What this means

Ponderosa pine fully dominates trends in growth, 

mortality, and removals in the BHNF. Given concerns 

about the stocking of ponderosa pine forests in light of 

wildfire and insect risks, active management in portions 

of the BHNF (e.g., salvage logging and density reduction 

harvests) has reduced stocking levels, resulting in a 

growth to removal ratio below 1, which may be reflected 

in the relatively low levels of ponderosa pine mortality 

compared to other species such as quaking aspen. The 

average annual mortality rate of ponderosa pine is less 

than that of growth and removals individually. Given 

the rates of mortality in species such as quaking aspen 

and paper birch, we would expect reductions in their 

contribution to overall tree species diversity into the 

future. In contrast, hardwood species such as bur oak 

and green ash have relatively high levels of growth in 

the context of their being a small component of overall 

BHNF volume, and could constitute larger portions of 

growing-stock volume in the distant future.

Carbon

Background

Collectively, forest ecosystems represent the largest 

terrestrial carbon sink on Earth. The accumulation of 

carbon in forests through sequestration helps to mitigate 

emissions of carbon dioxide to the atmosphere from 

sources such as forest fires and burning of fossil fuels. 

The FIA program does not directly measure forest 

carbon stocks in the BHNF. Instead, a combination 

of empirically derived carbon estimates (e.g., standing 

live trees) and models (e.g., carbon in soil organic 

matter based on stand age and forest type) are used 

to estimate the BHNF’s forest carbon. Estimation 

procedures are detailed by Smith et al. (2006) and 

Woodall et al. (2011).

What we found

The BHNF currently contains more than 55 million 

tons of carbon. Soil organic matter (SOM) represents 

the largest forest ecosystem carbon stock in the BHNF 

at more than 24 million tons, followed by live trees, 

woodland species, and saplings at more than 18 million 

tons (Fig. 16). Within the live-tree, woodland species, 

and sapling pool, merchantable boles contain the bulk of 

the carbon (~ 11.7 million tons) followed by roots (~ 3.4 

million tons) and stumps, tops, and limbs (~ 2.7 million 

tons). The majority of the BHNF’s forest carbon stocks 

are found in moderately aged stands, 61 to 100+ years 

old (Fig. 17). Early in stand development, most of the 

forest ecosystem carbon is in the SOM and belowground 

tree components. As forest stands mature, the ratio of 

aboveground to belowground carbon shifts, and by 

the 81 to 100 age class the aboveground components 

represent the majority of ecosystem carbon. This trend 

continues well into stand development as carbon 

accumulates in live and dead aboveground components. 

A look at carbon by forest-type group on a per unit area 

basis found that six of the seven types have between 

40 and 60 tons of carbon per acre (Fig. 18). Despite 

the similarity in per acre estimates, the distribution 

of forest carbon stocks by forest type is quite variable. 

In the ponderosa pine group, for example, 39 percent 

44%

2%

2% 16%

3%

Litter 

Live trees and saplings

Soil organic matter 

Total understory 

Standing dead 

Down dead 

Saplings and woodland species

Stumps, tops, and limbs

Merchantable boles 

Roots

6% 

21% 

1% 

5% 

Figure 16.—Total carbon stocks on forest land by forest ecosystem 

component in the Black Hills National Forest, 2005 (Wyoming) and 2007-2011 

(South Dakota).
12

FOREST FEATURES

(~ 19 tons per acre) of the forest carbon is in the live 

biomass, but in the pinyon/juniper group only 12 

percent (~ 6 tons per acre) is in the living material.

What this means

Carbon stocks in the forested components of the BHNF 

have increased substantially over the last several decades. 

The majority of forest carbon in the BHNF is found 

in moderately aged stands dominated by a relatively 

long-lived conifer species. This finding suggests that the 

BHNF forest carbon is generally expected to continue 

to increase as stands mature and accumulate carbon in 

aboveground and belowground components. Given the 

age class structure and species composition of forests in 

the BHNF, there may be opportunities to increase forest 

carbon stocks.

Standing Dead Trees (Snags)

Background

Standing dead trees (snags), from the time they die until 

they are fully decomposed, contribute to the structure 

and function of forest ecosystems. Snags are created 

naturally by extreme weather events, fire, insects, and 

pathogens, and these same biotic and abiotic agents 

contribute to the decomposition of standing dead wood. 

Until recently, the FIA program did not directly measure 

standing dead trees in the BHNF. Instead, estimates 

of standing dead tree biomass were modeled using 

geographic area, forest type, and growing-stock volume 

(Woudenberg et al. 2010). Standing dead trees are now 

measured directly and estimates of aboveground biomass 

are adjusted to account for density reductions and 

structural loss by decay class (Domke et al. 2011).

What we found

The nearly 20 million standing dead trees (at least 5 

inches d.b.h./d.r.c.) in the BHNF contain more than 

2.4 million tons of aboveground biomass. The majority 

of snag biomass (1.7 million oven-dry short tons) is 

found in the early stages of decomposition (see Domke 

et al. 2011 for a description of decay classes) in decay 

classes 1 to 3 (Fig. 19). Not surprisingly, the ponderosa 

pine forest-type group represents the largest proportion 

(62 to 88 percent) of biomass in each decay class. The 

majority (61 percent) of standing dead trees are found in 

the smallest diameter classes (5.0 to 9.0 inches d.b.h.); 

however, the bulk of the aboveground biomass is found 

in slightly larger diameter classes (7.0 to 15.0 inches 

d.b.h.) (Fig. 20). Ponderosa pine is the dominant forest 

type across diameter classes, and the proportion of the 

ponderosa pine type generally increases with increasing 

diameter. A look at the number of standing dead trees 

Aboveground 

Belowground 

Forest land 

0 

50 

100 

150 

200 

250 

300 

350 

400 

0 

2 

4 

6 

8 

10 

12 

14 

16 

18 

20 

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

Thousand Acres 

Forest C Stocks (million short tons) 

Stand-age Class (years) 

C in live biomass C in dead wood C in litter C in soil 

0 10 20 30 40 50 60 

Spruce/fir 

Pinyon/juniper 

Ponderosa pine 

Aspen/birch 

Other hardwoods 

Oak/hickory 

Nonstocked 

Forest C Stocks per Acre (short tons) 

Forest-type Group 

Figure 17.—Aboveground and belowground carbon stocks on forest land by 

stand-age class, Black Hills National Forest, 2005 (Wyoming) and 2007-2011 

(South Dakota).

Figure 18.—Carbon stocks by forest-type group and carbon pool per acre 

of forest land, Black Hills National Forest, 2005 (Wyoming) and 2007-2011 

(South Dakota).
13

FOREST FEATURES

per unit area across the elevation gradient in the BHNF 

suggests, in general, that the number of standing dead 

trees per acre increases with increasing elevation (Fig. 

21). Furthermore, the ratio of live to standing dead 

aboveground biomass decreases with increasing elevation, 

suggesting that standing dead trees, while present at all 

elevations, make up a much larger proportion of high 

elevation forests in the BHNF.

What this means

The MPB, once called the Black Hills beetle, has led 

to documented large-scale tree mortality pre-dating the 

establishment of the BHNF. Given the large proportion 

of ponderosa pine in the BHNF and the cyclical nature 

of MPB outbreaks as well as other mortality agents 

such as fires that have resulted in about 25 percent of 

the BHNF burned at some level since 2000, it is not 

surprising that there is a substantial amount of standing 

dead tree biomass across all stages of decay. The majority 

of standing dead trees in the BHNF are small and in 

the early stages of decay, suggesting relatively recent 

mortality. Early thinning treatments aimed at capturing 

mortality, decreasing fuel loads, and reducing stem 

density, particularly at high elevations, in stands that 

have historically been deemed sub-merchantable may 

now be an option given renewed interest in biomass 

utilization for energy. The MPB and fire, among other 

biotic and abiotic agents, are important to the structure 

and function of forest ecosystems in the BHNF. In the 

face of global change, maintaining a balance between 

standing dead tree structural attributes and fire danger 

will continue to require specific planning considerations 

and creative silviculture.

Other forest type 

Ponderosa pine 

Number of SD trees 

0 

1 

2 

3 

4 

5 

6 

7 

8 

0 

100 

200 

300 

400 

500 

600 

700 

800 

900 

1 2 3 4 5 

Standing Dead Trees (millions) 

Standing Dead-tree Biomass 

(thousand short tons)

Decay Class 

Other forest type 

Ponderosa pine 

Number of SD trees 

0 

1 

2 

3 

4 

5 

6 

7 

0 

50 

100 

150 

200 

250 

300 

350 

400 

450 

500 

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 21.0-22.9 

23.0-24.9 

Standing Dead Trees (millions) 

Standig Dead-tree Biomass 

(thousand short tons)

Diameter Class (inches) 

SDT/acre 

Ratio live:dead 

0 

5 

10 

15 

20 

25 

0 

5 

10 

15 

20 

25 

30 

35 

40 

45 

3-4 4-5 5-6 6-7 7 + 

Ratio of Live to Standing 

Dead-tree Biomass (short tons)

Standing Dead Trees per Acre 

Elevation (thousand feet) 

Figure 19.—Number of standing dead trees and aboveground biomass (ovendry short tons) by decay class, Black Hills National Forest, 2005 (Wyoming) and 

2007-2011 (South Dakota).

Figure 20.—Number of standing dead trees and aboveground biomass by 

diameter (d.b.h./d.r.c.) class, Black Hills National Forest, 2005 (Wyoming) and 

2007-2011 (South Dakota).

Figure 21.—Number of standing dead trees per acres by elevation and the 

ratio of live to standing dead tree biomass (short tons) in the Black Hills 

National Forest, 2005 (Wyoming) and 2007-2011 (South Dakota).
14

FOREST FEATURES

Down Woody Materials

Background

Down woody materials, in the various forms of fallen 

trees and litter fall, provide numerous ecological niches 

in the BHNF (e.g., wildlife habitat and stand structural 

diversity) while contributing toward forest fire hazards 

via surface woody fuels.

What we found

The down woody materials in the BHNF are dominated 

by litter and coarse woody debris (down dead wood with 

a minimum diameter of 3 inches and minimum length 

of 3 feet) (Fig. 22). The percentages of the total down 

woody materials represented by fine woody debris, coarse 

woody debris, duff, and litter were 10, 26, 13, and 51 

percent, respectively. The fuel loadings of down woody 

materials (time-lag fuel classes) in ponderosa pine forests 

of the BHNF were compared to the same forest type in 

the neighboring state of Montana (for fuel definitions see 

Woodall and Monleon 2008) (Fig. 23). Given the large 

sampling errors associated with the estimates, we cannot 

make definitive conclusions, but we can say that loadings 

of coarse woody debris and litter in the ponderosa pine 

forests of the BHNF were nearly four times larger than 

Montana’s.

What this means

The BHNF’s fuel loadings may be viewed as moderate 

within the larger context of national forests of the 

U.S., despite having down dead wood fuel loadings 

potentially larger for some fuel categories (e.g., litter) 

than ponderosa pine forests in Montana, a neighboring 

western state. Fuel loads typically increase in response to 

disturbances such as wind or mortality events; however, 

despite the many years of mortality from MPB the 

BHNF fuel load does not appear to be excessive when 

compared to other disturbance events. A blowdown 

disturbance in the Superior National Forest of Minnesota 

produced fuel loads five times greater than seen in 

the BHNF (Woodall and Nagel 2007). However, the 

combination of continuing tree mortality, coupled with 

the potential for drought in the BHNF, suggests the need 

for continued monitoring and potential mitigation of fire 

hazards (i.e., down woody material fuels) in varying areas 

of the BHNF landscape.

51% 10% 

13% 

26% 

FWD 

CWD 

Duff

Litter 

BHNF 

Montana 

0.0 

0.5 

1.0 

1.5 

2.0 

2.5 

3.0 

3.5 

4.0 

4.5 

5.0 

1-hr 10-hr 100-hr 1,000+ hr Duff Litter 

Mean Fuel Loadings (short tons/acre) 

Fuel Class 

Figure 22.—Proportion of total down woody material biomass by down 

woody material component on forest land, Black Hills National Forest, 2005 

(Wyoming) and 2006-2011 (South Dakota).

Figure 23.—Mean fuel loadings (tons per forest land acre) and associated 

sampling errors by fuel class of ponderosa pine forests in Black Hills National 

Forest and Montana, 2005 (Wyoming) and 2006-2011 (South Dakota and 

Montana).
15

Forest Economics

Sunday Gulch Timber Sale, 2010. Photo by Beth Steinhauer, U.S. Forest Service, Black Hills National Forest.
16

Forest economics

Growing-Stock and 

Sawtimber Volume

Background

Growing-stock volume is the amount of merchantable 

wood in live commercial tree species that are sound, 

reasonably straight, and 5 inches d.b.h. or greater. This 

measure has traditionally been used to estimate the 

volume of wood material available for the manufacture 

of timber products. Sawtimber trees are live trees of 

commercial species that contain either one 12-foot 

or two noncontiguous 8-foot logs that are free of 

defect. Hardwoods must be at least 11 inches d.b.h. 

and softwoods must be 9 inches d.b.h. to qualify as 

sawtimber. Sawtimber volume is defined as the net 

volume of the saw log portion of a tree, measured in 

board feet, from a 1-foot stump to the merchantable top 

(9 inches for hardwoods and 7 inches for softwoods). 

Estimates of sawtimber volume are used to determine 

the monetary value of wood volume and to identify 

the quantity of merchantable wood. Knowing both 

measures of volume is important for economic planning 

and development, and are essential when evaluating 

sustainable forest management.

A system of standards, called tree grades, are used to 

rate the quality of a tree for producing forest products. 

The meanings differ by species group, but grade one is 

the highest quality. The quality decreases as the grade 

number increases up to grade five. Many factors affect 

the grading including defects, curvature, and length 

of usable sections in the saw log portion. See U.S. 

Forest Service (2010), Appendix E, for the grading 

specifications.

What we found

The net volume of growing stock on timberland in the 

BHNF was estimated at 1.51 billion cubic feet, or 1,325 

cubic feet of growing stock per acre of timberland. The 

spruce/fir forest-type group had the highest volume of 

growing stock per acre of timberland, despite being a 

distant second place behind the ponderosa pine group 

in terms of net growing-stock volume (Fig. 24). Not 

surprisingly, ponderosa pine trees accounted for more 

than 1.43 billion cubic feet (94 percent) of the total 

growing-stock volume. All hardwood species combined 

for 22.6 million cubic feet. Quaking aspen made up 63 

percent of the total hardwood growing-stock volume.

GS volume/acre 

Net GS volume 

0 

200 

400 

600 

800 

1,000 

1,200 

1,400 

1,600 

0 

200 

400 

600 

800 

1,000 

1,200 

1,400 

1,600 

1,800 

Spruce/fir 

Ponderosa pine 

Other hardwoods 

Aspen/birch 

Oak/hickory 

Pinyon/juniper 

Net Growing-stock Volume (million ft ) 

Growing-stock Volume

(ft3/acre of timberland)

Forest-Type Group 

The net sawtimber volume on BHNF timberland was 

estimated at more than 4.98 billion board feet (Scribner 

rule), which includes volume that may be located on 

inaccessible sites (e.g., steep slopes or access restrictions 

due to private land). More than one-third of the total 

sawtimber volume was in the 13.0- to 14.9-inch and 

15.0- to 16.9-inch diameter classes (Fig. 25). In terms 

of sawtimber quality, 72 percent of sawtimber volume 

came from grade three trees while only slightly more 

than 1 percent of the volume was graded less than grade 

three (Fig. 26). For white spruce, 83 percent of total 

sawtimber volume came from grade one trees.

Figure 24.—Net volume of growing stock per acre of timberland and net 

growing-stock volume on timberland by forest-type group, Black Hills National 

Forest, 2005 (Wyoming) and 2006-2011 (South Dakota).
17

Forest economics

What this means

Although the BHNF is currently experiencing a MPB 

epidemic that is increasing tree mortality, abundant live 

growing-stock and sawtimber volume is still available. 

While a majority of sawtimber is not in the top quality 

grade, it is still an important asset to the timber products 

industry of the surrounding Black Hills region.

Timber Products Output

Background

The harvesting and processing of timber products 

produces a stream of income shared by timber owners, 

managers, marketers, loggers, truckers, and processors. 

In 2007, the wood products and paper manufacturing 

industries (NAICS codes 321 and 322) in South 

Dakota, where most of the BHNF is located, employed 

about 2,470 people, with an average annual payroll of 

$86.1 million and total value of shipments of $560.9 

million (U.S. Census Bureau 2007). To strengthen the 

commercial wood production portion of multiple use 

management of the BHNF, it is important to know 

the species, amounts, and locations of timber being 

harvested.

In 2009, a cooperative effort between the South Dakota 

Department of Agriculture, Resource Conservation 

and Forestry Division (SDRCF) and the Northern 

Research Station (NRS-FIA) used a questionnaire 

designed to determine the size and composition of South 

Dakota’s forest products industry, its use of roundwood 

(round sections cut from trees), and its generation 

and disposition of wood residues. SDRCF personnel 

contacted via mail and telephone all primary woodusing mills in the State. Completed questionnaires were 

sent to NRS-FIA for processing. To compile data to 

include in this report, mills were later contacted and 

asked what percent of the wood processed at the mill 

came from the BHNF. A similar study was conducted 

for the mills in Wyoming in 2010 by the University 

of Montana’s Bureau of Business and Economic 

Research, Forest Industry Research program. As part 

of data processing, all industrial roundwood volumes 

reported were converted to standard units of measure 

using regional conversion factors. Data on industrial 

roundwood receipts at mills drawing from the BHNF 

were added to a regional timber removals database to 

provide a complete assessment of the BHNF’s timber 

products output.

0 

200 

400 

600 

800 

1,000 

1,200 

1,400 

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 

Sawtimber Volume 

(million board feet Scribner rule)

Diameter Class (inches) 

Bur oak 

Quaking aspen 

Ponderosa pine 

White spruce 

0 

500 

1,000 

1,500 

2,000 

2,500 

3,000 

3,500 

4,000 

Grade 1 Grade 2 Grade 3 Lower than 

grade 3 

Sawtimber Volume 

(million board feet Scribner rule)

Tree Grade 

Figure 25.—Sawtimber volume (Scribner rule) on timberland by diameter 

class, Black Hills National Forest, 2005 (Wyoming) and 2006-2011 (South 

Dakota). Error bars show the 68 percent confidence interval.

Figure 26.—Sawtimber volume (Scribner rule) by species and tree grade, 

Black Hills National Forest, 2005 (Wyoming) and 2006-2011 (South Dakota).
18

Forest economics

What we found

In 2009, there were 14 active primary wood-using mills 

that processed 29.3 million cubic feet of industrial 

roundwood from the BHNF into lumber, particleboard, 

posts, and other wood products. Eighty-two percent of 

the total was harvested in the South Dakota portion of 

the forest, and the remainder was processed in Wyoming. 

The BHNF is so important to South Dakota’s forest 

products industry that more than 80 percent of the 

industrial roundwood processed in the State came from 

the BHNF. Saw logs accounted for 97 percent of the 

industrial roundwood harvested from the BHNF (Fig. 

27). Other products harvested were posts, pulpwood, 

and cabin logs. Ponderosa pine accounted for 99 percent 

of the industrial roundwood. A small amount of white 

spruce was also harvested.

3% 

97% 

<1% 

Saw logs 

Posts 

Other products 

What this means

Harvesting of industrial roundwood on the BHNF 

provides not only forest products, but also an economic 

means to thin dense stands that are susceptible to MPB 

and forest fires. Some forest stands are being thinned 

without markets for the wood in an attempt to reduce 

the potential for MPB to access certain areas across the 

landscape during the current epidemic that has been 

affecting the BHNF for a decade or more, while also 

reducing forest fire hazards. This requires that the wood 

be stacked and burned to potentially reduce the severity 

of and aid in suppressing potential future wildfires. An 

improvement in the economy may lead to an increase in 

the markets for this unused wood material. This material 

could also be a supply source for a small, local biomassbased facility (e.g., wood pellets).

Figure 27.—Industrial roundwood products harvested from the Black Hills 

National Forest, 2009.
19

Data Sources and Techniques

Aerial photography of Inyan Kara Mountain, Bearlodge Region of the Black Hills National Forest. 

Photo by Gary Chancey, U.S. Forest Service, Black Hills National Forest.
20

Data Sources and Techniques

Forest Inventory

Information on the condition and status of forests in 

the Black Hills National Forest was obtained from the 

Northern Research Station’s Forest Inventory and Analysis 

(NRS-FIA) program. The inventory in South Dakota 

was performed under an annual inventory system in 

which one-fifth of the field plots (considered one panel) 

in the State are measured each year. The entire inventory 

is completed every 5 years. Annual inventory has been 

done in South Dakota since 2001. Historically, FIA 

inventoried each state on a periodic cycle that averaged 

about 12 years. The need for timely and consistent data 

across large geographical regions along with national 

legislative mandates resulted in the annual inventory 

program. As of yet, an annual inventory has not been 

completed in the state of Wyoming, making an inventory 

of the BHNF an especially challenging endeavor. The last 

periodic inventory occurred in Wyoming in the year 2000 

and was performed by the Interior West Forest Inventory 

and Analysis (IW-FIA) program. In cooperation with the 

BHNF, field crews from NRS-FIA measured 35 plots in 

the BHNF on the Wyoming side in 2005 so a complete 

report could be compiled. Data for this report include 

the most recent 5-year inventory period for the South 

Dakota portion of the BHNF, 2007–2011 and the 2005 

Wyoming data. Growth, removals, and mortality (GRM) 

estimates were made using the 2002–2006 South Dakota 

inventory and the 2000 Wyoming inventory. The 2000 

periodic inventory for Wyoming was valid for GRM 

estimation because the plot design was similar to the 

national annual inventory plot design; however, because 

of regional differences in data compilation between NRSFIA and IW-FIA, unique data compilation procedures 

had to be developed.

Inventories are conducted in three phases. During 

the first phase, aerial photographs, digital orthoquads 

(DOQs), and satellite imagery are used for initial plot 

measurement via remotely sensed data and stratification. 

Analysts determine a digitized geographic location for 

each field plot and a human interpreter assigns the plot 

a land cover/use. All plot locations that could possibly 

contain accessible forest lands that satisfy FIA’s definition 

of forest land are selected for further measurement via 

field crew visits.

The second phase of the inventory consists of 

measuring the annual sample of field plots. Current 

FIA precision standards require a sampling intensity 

of one plot for approximately every 6,000 acres. FIA 

has divided the entire area of the United States into 

nonoverlapping hexagons, each of which contains 

5,937 acres (McRoberts 1999). The total Federal base 

sample of plots was systematically divided into five 

interpenetrating, nonoverlapping subsamples or panels. 

Each year the plots in a single panel are measured, 

and panels are selected on a 5-year, rotating basis. For 

estimation purposes, the measurement of each panel 

of plots may be considered an independent systematic 

sample of all land in a state. Field crews measure 

vegetation on plots forested at the time of the last 

inventory and on plots currently classified as forest by 

trained photointerpreters using aerial photos or DOQs. 

In this BHNF inventory only plots from the South 

Dakota inventory that were completely or partially on 

BHNF land were included in the data compilation in 

addition to the supplemental Wyoming plots that were 

all completely on BHNF land.

The overall Phase 2 (P2) plot layout consists of four 

subplots. The centers of subplots 2, 3, and 4 are located 

120 feet from the center of subplot 1. The azimuths 

to subplots 2, 3, and 4 are 0, 120, and 240 degrees, 

respectively. Trees with a d.b.h./d.r.c. 5 inches and larger 

are measured on a 24-foot-radius (1/24 acre) circular 

subplot. All trees less than 5 inches d.b.h. are measured 

on a 6.8-foot-radius (1/300 acre) circular microplot 

located 12 feet east of the center of each of the four 

subplots. Forest conditions that occur on any of the four 

subplots are recorded. Factors that differentiate forest 

conditions are changes in forest type, stand-size class, 

land use, ownership, and density.

The third phase focuses on forest health. Phase 3 (P3) 

plots consist of a 1:16 subset of P2 plots with one 

P3 plot for about every 95,000 acres. Measurements 

on these plots are obtained by field crews during 
21

Data sources and techniques

the growing season and include an extended suite of 

ecological data such as down woody material. Further 

information about P2 and P3 data collection can be 

found at http://fia.fs.fed.us/library/fact-sheets/.

A Comparison of Volume Models for 

Ponderosa Pine

The volume of a tree can be precisely determined by 

immersing it in a pool of water and measuring the 

amount of water displaced. Because such a process is 

destructive and cost prohibitive, models of tree volume 

based on tree metrics (e.g., tree diameter) must be used 

to estimate volume. Often, there are a variety of tree 

volume models for common tree species. For ponderosa 

pine in the BHNF, FIA-NRS uses tree volume equations 

based on Myers (1964).

Other tree volume equations have been developed 

for ponderosa pine in the BHNF, most notably, the 

Flewelling profile model (based on work presented in 

Flewelling and Raynes 1993 and Flewelling 1993) and 

the Czaplewski profile model (Czaplewski et al. 1989). 

The Myers volume equation relies on species, d.b.h., 

and total height to calculate tree net volume (from 

a 1-foot stump to a 4-inch top); the Flewelling and 

Czaplewski profile models also require the height to the 

merchantable top (4.0 inches). To compare the Myers 

tree volume equation to the Flewelling and Czaplewski 

versions, Microsoft Excel Volume Functions were 

installed from the National Volume Estimator Library 

(NVEL) Web site located at: http://www.fs.fed.us/fmsc/

measure/volume/nvel/index.php. The NVEL Excel 

Volume Functions allow tree volumes to be calculated 

using different volume equations.

NRS-FIA estimated that the net volume of live 

ponderosa pine trees 5 inches in diameter or greater on 

forest land in the BHNF was 1.5 billion cubic feet using 

the Myers tree volume equations (Fig. 28). The NVEL 

Excel Volume Functions produced an estimate of 1.6 

billion cubic feet using the Czaplewski profile model (a 

difference of 6 percent) and 1.4 billion cubic feet using 

the Flewelling profile model (a difference of -9 percent).

Czaplewski profile model 

Myers equation used by FIA 

Flewelling profile model 

0 

50 

100 

150 

200 

250 

300 

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 + 

Net Volume (million ft ) 

Diameter Class (inches) 

Figure 28.—Net volume of live ponderosa pine trees (at least 5 inches 

d.b.h./d.r.c.), in million cubic feet, on forest land by diameter class and volume 

equation model, Black Hills National Forest, 2005 (Wyoming) and 2006-2011 

(South Dakota).

When looking at the estimated tree volumes among a 

variety of models, it is important to assess differences 

across a range of diameters. For ponderosa pine in 

South Dakota, the Czaplewski profile model appears to 

provide larger estimates of small-diameter tree volume 

and smaller estimates of large-diameter tree volume 

compared to the Myers volume equation. On the other 

hand, the Flewelling profile model had smaller estimates 

of small-diameter tree volume when compared with the 

Myers volume equation; however, as the tree diameter 

became larger, the difference between the two was 

reduced. The difference between the total net volume of 

ponderosa pine trees 21 inches or greater using Myers 

volume equations and the Flewelling profile model was 

less than 0.5 percent.
22

Glossary

All live tree: All living trees. All size classes, all tree 

classes, and both saw log and non-saw log species are 

included.

Average annual mortality: The average annual change 

in mortality of trees between inventories. This estimate 

can be provided in cubic feet for all trees and growingstock trees that died, or in board feet for sawtimber trees 

that died.

Average annual net growth: The average annual change 

in the volume of trees between inventories. Components 

include the change in volume of trees that have met the 

minimum size requirements over the inventory period, 

plus the volume of trees reaching the minimum size 

during the period (ingrowth), minus the volume of trees 

that died during the period, minus the volume of cull 

during the period. Mortality removals (trees killed in 

the harvesting process and left on site) and diversion 

removals (trees removed from the forest land base due to 

a change from forest to nonforest land) are not included. 

This estimate can be provided in cubic feet for live and 

growing-stock trees or in board feet for sawtimber trees.

Average annual removals: The average annual change 

in removals of trees between inventories. The estimate 

includes harvest removals, mortality removals (trees 

killed in the harvesting process and left on site), and 

diversion removals (trees removed from the forest land 

base due to a change from forest to nonforest land). 

This estimate can be provided in cubic feet for live and 

growing-stock trees or in board feet for sawtimber trees.

Biomass: The aboveground weight of live trees 

(including bark but excluding foliage) reported in dry 

tons (dry weight). Biomass has four components:

Bole: Biomass of a tree from 1 foot above the ground 

to a 4-inch top outside bark or to a point where the 

central stem breaks into limbs.

 Tops and limbs: Total biomass of a tree from a 1-foot 

stump minus the bole.

1-to 5-inch trees: Total aboveground biomass of a tree 

from 1 to 5 inches d.b.h.

Stumps: Biomass of a tree 5 inches d.b.h. and larger 

from the ground to a height of 1 foot.

Board foot: A unit of lumber measuring 1 foot long, 

1 foot wide, and 1 inch thick, or its equivalent. The 

International 1⁄4-inch rule is used as the U.S. Forest 

Service standard log rule in the eastern United States; 

however, the Scribner rule is mainly used in the Black 

Hills area.

Coarse woody debris (CWD): Dead branches, twigs, 

and wood splinters 3.0 inches in diameter and larger 

measured at the smallest end.

Commercial species: Tree species suitable for industrial 

wood products.

Cull tree: A live tree, 5.0 inches in d.b.h. or larger, that 

is unmerchantable for saw logs now or prospectively 

because of rot, roughness, or species (see definitions for 

rotten and rough trees).

Decay class: Qualitative assessment of stage of decay 

(five classes) of coarse woody debris based on visual 

assessments of color of wood, presence/absence of twigs 

and branches, texture of rotten portions, and structural 

integrity.

Diameter at breast height (d.b.h.): The diameter of a 

tree stem, located at 4.5 feet above the ground (breast 

height) on the uphill side of a tree. The point of diameter 

measurement may vary on abnormally formed trees.

Diameter at root collar (d.r.c.): The diameter of a tree 

(usually a woodland species), measured outside of the 

bark at the ground line or stem root collar.
23

Diameter class: A classification of trees based on d.b.h./

d.r.c. With 2-inch diameter classes, the 6-inch class, for 

example, includes trees 5.0 through 6.9 inches d.b.h.

Down woody material (DWM): Woody pieces of 

trees and shrubs that have been uprooted (no longer 

supporting growth) or severed from their root system, 

not self-supporting, and lying on the ground. 

Dry weight: The weight of wood and bark as it would 

be if it had been oven dried; usually expressed in pounds 

or short tons.

Duff: A soil layer dominated by organic material derived 

from the decomposition of plant and animal litter and 

deposited on either an organic or a mineral surface. 

This layer is distinguished from the litter layer in that 

the original organic material has undergone sufficient 

decomposition that the source of this material (e.g., 

individual plant parts) no longer can be identified.

Epidemic: (1) Entomology: pertaining to populations of 

plants, animals, and viruses that build up, often rapidly, 

to unusually and generally injuriously high levels. 

Synonym: outbreak. Many insect and other animal 

populations cycle periodically or irregularly between 

endemic and epidemic levels. (2) Pathology: a disease 

sporadically infecting a large number of hosts in an area 

and causing considerable loss (Helms 1998).

Fiber products: Products derived from wood and bark 

residues, such as pulp, composition board products, and 

wood chips.

Fine woody debris (FWD): Dead branches, twigs, and 

wood splinters 0.1 to 2.9 inches in diameter. 

Forest land: 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 heavily forested and nonforested lands that are 

at least 10 percent stocked with trees and forest areas 

adjacent to urban and builtup lands. Also included are 

pinyon-juniper and chaparral areas and afforested areas. 

The minimum area for classification of forest land is 1 

acre and 120 feet wide measured stem-to-stem from the 

outermost edge. Unimproved roads and trails, streams, 

and clearings in forest areas are classified as forest if less 

than 120 feet wide.

Forest type: A classification of forest land based on 

the species presently forming a plurality of the livetree stocking. If softwoods predominate (50 percent or 

more), then the forest type will be one of the softwood 

types and vice versa for hardwoods. 

Forest-type group: Combinations of forest types that 

share closely associated species or site requirements and 

are generally combined for brevity of reporting.

Fuel class: Categories of forest fire fuels defined by 

the approximate amount of time it takes for moisture 

conditions to fluctuate. Large coarse woody debris pieces 

take longer to dry out than smaller fine woody pieces.

1,000-hour fuels: Coarse woody debris with a transect 

diameter ≥ 3.0 inches and ≥ 3.0 feet long.

100-hour fuels: Fine woody debris with a transect 

diameter between 1.0 and 2.9 inches.

10-hour fuels: Fine woody debris with a transect 

diameter between 0.25 and 0.9 inches.

1-hour fuels: Fine woody debris with a transect 

diameter < 0.24 inches.

Growing stock: A classification of timber inventory 

that includes live trees of commercial species meeting 

specified standards of quality or vigor. Rough and rotten 

cull trees are excluded. When associated with volume, 

this includes only trees 5.0 inches d.b.h. and larger. 

Hardwood: A dicotyledonous tree, usually broad-leaved 

and deciduous. 
24

 Soft hardwoods: A category of hardwood species with 

wood generally of low specific gravity (less than 0.5). 

Notable examples include red maple, paper birch, 

quaking aspen, and American elm. 

Hard hardwoods: A category of hardwood species with 

wood generally of high specific gravity (greater than 

0.5). Notable examples include sugar maple, yellow 

birch, black walnut, and oaks. 

Industrial wood: All commercial roundwood products 

except fuelwood.

Litter: Undecomposed or only partially decomposed 

organic material that can be readily identified (e.g., plant 

leaves, twigs). 

Live cull: A classification that includes live, cull trees. 

When associated with volume, it is the net volume in 

live, cull trees that are 5.0 inches d.b.h. and larger.

Mean annual increment (MAI) at culmination: A 

measure of the productivity of forest land expressed as 

the average increase in cubic feet of wood volume per 

acre per year. For a given species and site index, the mean 

is based on the age at which the MAI culminates for fully 

stocked natural stands. The MAI is based on the site 

index of the plot (Azuma et al. 2004).

Merchantable: Refers to a pulpwood or saw log 

section that meets pulpwood or saw log specifications, 

respectively. 

National Forest: An ownership class of Federal lands, 

designated by Executive order or statute as National 

Forests or purchase units, and other lands under 

the administration of the Forest Service, including 

experimental areas. 

Net volume in cubic feet: The gross volume in cubic 

feet less deductions for rot, roughness, and poor form. 

Volume is computed for the central stem from a 1-foot 

stump to a minimum 4.0-inch top diameter outside 

bark, or to the point where the central stem breaks 

into limbs. 

Noncommercial species: Tree species of typically small 

size, poor form, or inferior quality, which normally do 

not develop into trees suitable for industrial roundwood 

products.

Nonforest land: Land that has never supported forests 

and lands formerly forested where use of timber 

management is precluded by development for other 

uses. (Note: Includes area used for crops, improved 

pasture, residential areas, city parks, improved roads of 

any width and adjoining clearings, powerline clearings 

of any width, and 1- to 4.5-acre areas of water classified 

by the Bureau of the Census as land. If intermingled in 

forest areas, unimproved roads and nonforest strips must 

be more than 120 feet wide, and clearings, etc., must be 

more than 1 acre in area to qualify as nonforest land.) 

Nonstocked areas: Timberland less than 10 percent 

stocked with live trees.

Poletimber trees: Live trees at least 5.0 inches in d.b.h. 

but smaller than sawtimber trees. 

Primary wood-using mill: A mill that converts 

roundwood products into other wood products. 

Common examples are sawmills that convert saw logs 

into lumber and pulpmills that convert pulpwood into 

wood pulp.

Pulpwood: Roundwood, whole-tree chips, or wood 

residues used for the production of wood pulp. 

Reserved forest land: Forest land withdrawn from 

timber utilization through statute, administrative 

regulation, or designation without regard to productive 

status.

Residues: Bark and woody materials that are generated 

in primary wood-using mills when roundwood products 

are converted to other products. Examples include 

slabs, edgings, trimmings, miscuts, sawdust, shavings, 

veneer cores and clippings, and pulp screenings. Includes 

bark residues and wood residues (both coarse and fine 

materials) but excludes logging residues. 
25

Rotten tree: A live tree of commercial species that does 

not contain a saw log now or prospectively primarily 

because of rot (that is, when rot accounts for more than 

50 percent of the total cull volume). 

Rough tree: (a) A live tree of commercial species 

that does not contain a saw log now or prospectively 

primarily because of roughness (that is, when sound 

cull due to such factors as poor form, splits, or cracks 

accounts for more than 50 percent of the total cull 

volume); or (b) a live tree of noncommercial species. 

Roundwood products: Logs, bolts, and other round 

timber generated from harvesting trees for industrial or 

consumer use. 

Salvable dead tree: A downed or standing dead tree 

considered currently or potentially merchantable by 

regional standards. 

Sampling error: Difference between a population value 

and a sample estimate that is attributable to the sample, 

as distinct from errors due to bias in estimation, errors 

in observation, etc. Sampling error is measured as the 

standard error of the sample estimate (Helms 1998).

Saplings: Live trees 1.0 inch through 4.9 inches d.b.h. 

Saw log: A log meeting minimum standards of diameter, 

length, and defect, including logs at least 8 feet long, 

sound and straight, and with a minimum diameter 

inside bark of 6 inches for softwoods and 8 inches for 

hardwoods, or meeting other combinations of size and 

defect specified by regional standards. 

Sawtimber tree: A live tree of commercial species 

containing at least a 12-foot saw log or two 

noncontiguous saw logs 8 feet or longer, and meeting 

regional specifications for freedom from defect. 

Softwoods must be at least 9.0 inches d.b.h. Hardwoods 

must be at least 11.0 inches d.b.h.

Sawtimber volume: Net volume of the saw log portion 

of live sawtimber in board feet, International 1⁄4-inch rule 

(unless specified otherwise), from stump to a minimum 

7.0 inches top d.o.b. for softwoods and a minimum 9.0 

inches top d.o.b. for hardwoods. 

Seedlings: Live trees less than 1.0 inch d.b.h. and at least 

1 foot in height.

Snag: A standing dead tree. In the current inventory, a 

snag must be 5.0 inches d.b.h./d.r.c. and 4.5 feet tall, 

and have a lean angle less than 45 degrees from vertical. 

A snag may be either self-supported by its roots or 

supported by another tree or snag. 

Softwood: A coniferous tree, usually evergreen, having 

needles or scale-like leaves. 

Stand: A group of trees on a minimum of 1 acre of forest 

land that is stocked by forest trees of any size.

Stand age: A stand descriptor that indicates the average 

age of the live dominant and codominant trees in the 

predominant stand-size class of a condition.

Stand origin: A classification of forest stands describing 

their means of origin.

Planted: Planted or artificially seeded.

Natural: No evidence of artificial regeneration.

Stand-size class: A classification of forest land based on 

the size class of live trees in the area. The classes are as 

follows: 

 Sawtimber: Forest land stocked with at least 10 

percent of full stocking with live trees with half or 

more of such stocking in poletimber or sawtimber 

trees or both, and in which the stocking of sawtimber 

is at least equal to that of poletimber.
26

Poletimber: Forest land stocked with at least 10 

percent of full stocking with live trees with half or 

more of such stocking in poletimber or sawtimber 

trees or both, and in which the stocking of poletimber 

exceeds that of sawtimber.

Seedling-sapling: Forest land stocked with at least 10 

percent of full stocking with live trees with half or 

more of such stocking in seedlings or saplings or both. 

Nonstocked: Forest land stocked with less than 10 

percent of full stocking with live trees. Examples 

are recently cutover areas or recently reverted 

agricultural fields.

Stocking: The degree of occupancy of land by trees, 

measured by basal area or number of trees by size and 

spacing, or both, compared to a stocking standard; that 

is, the basal area or number of trees, or both, required to 

fully utilize the growth potential of the land. 

Timberland: Forest land that is producing or is 

capable of producing crops of industrial wood and 

not withdrawn from timber utilization by statute or 

administrative regulation. (Note: Areas qualifying as 

timberland are capable of producing in excess of 20 

cubic feet per acre per year of industrial wood in natural 

stands. Currently inaccessible and inoperable areas are 

included.) 

Timber products output: All timber products cut from 

roundwood and byproducts of wood manufacturing 

plants. Roundwood products include logs, bolts, or 

other round sections cut from growing-stock trees, 

cull trees, salvable dead trees, trees on nonforest land, 

noncommercial species, sapling-size trees, and limbwood. 

Byproducts from primary manufacturing plants include 

slabs, edging, trimmings, miscuts, sawdust, shavings, 

veneer cores and clippings, and screenings of pulpmills 

that are used as pulpwood chips or other products.

Tree: 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. 

Tree grade: A classification of the sawlog portion of 

sawtimber trees based on (1) the grade of the butt log, 

or (2) the ability to produce at least one 12-foot or two 

8-foot logs in the upper section of the sawlog portion. 

Tree grade is an indicator of quality; grade one is the best 

quality (see U.S. Forest Service 2010, Appendix E for 

grading specifications).

Tree-size class: A classification of trees based on 

diameter at breast height, including sawtimber trees, 

poletimber trees, saplings, and seedlings.

 Sawtimber-size trees: Softwood timber species ≥ 9.0 

inches d.b.h., and hardwood timber species ≥ 11.0 

inches d.b.h.

Poletimber-size trees: Softwood timber species 5.0 to 

8.9 inches d.b.h. and hardwood timber species 5.0 to 

10.9 inches d.b.h.

Saplings: Live trees 1.0 inch through 4.9 inches d.b.h.

Seedlings: Live trees less than 1.0 inch d.b.h. and at 

least 1 foot in height.

Tops: The wood of a tree above the merchantable height 

(or above the point on the stem 4.0 inches diameter 

outside bark (d.o.b.) or to the point where the central 

stem breaks into limbs). It includes the usable material in 

the uppermost stem.

Upper stem portion: Portion of a sawtimber tree that 

is above the saw log portion. Begins at a top of 7 inches 

d.o.b. for softwoods and 9.0 inches d.o.b. for hardwoods, 

or where the central stem breaks into limbs.
27

Literature Cited

Azuma, D.L.; Dunham, P.A.; Hiserote, B.A.;Veneklase, 

C.F. 2004. Timber resource statistics for eastern 

Oregon, 1999. Resour. Bull. PNW-RB-238. Portland, 

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

Pacific Northwest Research Station. 42 p.

Czaplewski, R.L.; Brown, A.S.; Walker, R.C. 1989. 

Profile models for estimating log end diameters in 

the Rocky Mountain region. Res. Pap. RM-284. Fort 

Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station. 7 p.

Domke, G.M.; Woodall, C.W.; Smith, J.E. 2011. 

Accounting for density reduction and structural 

loss in standing dead trees: Implications for forest 

biomass and carbon stock estimates in the United 

States. Carbon Balance and Management. 6:14.

Flewelling, J.W. 1993. Variable-shape stemprofile predictions for western hemlock. Part II. 

Predictions from dbh, total height, and upper stem 

measurements. Canadian Journal of Forest Research. 

23(3): 537-544.

Flewelling, J.W.; Raynes, L.M. 1993. Variable-shape 

stem-profile predictions for western hemlock. Part 

I. Predictions from dbh and total height. Canadian 

Journal of Forest Research. 23(3): 520-536.

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

MD: Society of American Foresters. 210 p.

Long, J.N. 1985. A practical approach to density 

management. Forest Chronicle. 61(1): 23-27.

Magurran, A.E. 1988. Ecological diversity and its 

measurement. Princeton, NJ: Princeton University 

Press. 192 p.

McRoberts, R.E. 1999. Joint annual forest inventory 

and monitoring system, the North Central 

perspective. Journal of Forestry. 97(12): 27-31.

Myers, C.A. 1964. Volume table and point sampling 

factors for ponderosa pine in the Black Hills. Res. 

Pap. RM-8. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest and 

Range Experiment Station. 16 p.

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.

U.S. Census Bureau. 2007. 2007 Economic Census, 

South Dakota—Table 2 Selected Statistics by 

Economic Sector and Subsector: 2007. Generated by 

American FactFinder; <http://factfinder.census.gov> 

(Accessed September 12, 2012).

U.S. Forest Service. 2010. Forest Inventory and 

Analysis national core field guide; Volume I: Field 

data collection procedures for P2 plots, version 5.0.

Available at http://www.nrs.fs.fed.us/fia/data-collection/ 

(Accessed October 16, 2012).

Woodall, C.W.; Nagel, L.M. 2007. Down woody fuel 

loadings dynamics of a large-scale blowdown in 

northern Minnesota. Forest Ecology and Management. 

247: 194-199.

Woodall, C.W.; Monleon, V.J. 2008. Sampling 

protocols, estimation procedures, and analytical 

guidelines for down woody materials indicator of the 

Forest Inventory and Analysis Program. Gen. Tech. 

Rep. NRS-22. Newtown Square, PA: U.S. Department 

of Agriculture, Forest Service, Northern Research 

Station. 68 p.
28

Woodall, C.W.; Perry, C.H.; Miles, P.D. 2006. Relative 

density of forests in the United States. Forest Ecology 

and Management. 226: 368-372.

Woodall, C.W.; Heath, L.S.; Domke, G.M.; Nichols, 

M.C. 2011. Methods and equations for estimating 

aboveground volume, biomass, and carbon for trees 

in the U.S. forest inventory, 2010. Gen. Tech. Rep. 

NRS-66. Newtown Square, PA: U.S. Department of 

Agriculture, Forest Service, Northern Research Station. 

30 p.

Woudenberg, S.W.; Conkling, B.L.; O’Connell, B.M.; 

LaPoint, E.B.; Turner, J.A.; Waddell, K.L. 2010. The 

Forest Inventory and Analysis database: Database 

description and users manual version 4.0 for P2.

Gen. Tech. Rep. RMRS-GTR-245. Fort Collins, CO: 

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

Mountain Research Station. 336 p.
29

Tables

Table 1.—Area of forest land, in thousand acres, by 

forest-type group, forest type, and owner category, Black 

Hills National Forest, 2011

Table 2.—Area of timberland, in thousand acres, 

by major forest-type group, stand origin, and owner 

category, Black Hills National Forest, 2011

Table 3.—Area of timberland, in thousand acres, by 

forest-type group, forest type, and stand-size class, Black 

Hills National Forest, 2011

Table 4.—Net volume of live trees (at least 5 inches 

d.b.h./d.r.c.), in thousand cubic feet, on forest land by 

species group, species, and owner category, Black Hills 

National Forest, 2011

Table 5.—Net volume of live and salvable dead trees (at 

least 5 inches d.b.h./d.r.c.), in thousand cubic feet, on 

timberland by class of timber and softwood/hardwood 

species category, Black Hills National Forest, 2011

Table 6.—Net volume of growing-stock trees (at 

least 5 inches d.b.h./d.r.c.), in thousand cubic feet, 

on timberland by forest-type group, forest type, and 

softwood/hardwood species category, Black Hills 

National Forest, 2011

Table 7.—Net volume of growing-stock trees (at least 

5 inches d.b.h./d.r.c.), in thousand cubic feet, on 

timberland by species group, species, and diameter class, 

Black Hills National Forest, 2011

Table 8a.—Net volume of sawtimber trees, in thousand 

board feet (International 1⁄4-inch rule), on timberland 

by species group, species, and diameter class, Black Hills 

National Forest, 2011

Table 8b.—Net volume of sawtimber trees, in thousand 

board feet (Scribner rule), on timberland by species 

group, species, and diameter class, Black Hills National 

Forest, 2011

Table 9.—Aboveground dry weight of live trees (at 

least 1 inch d.b.h./d.r.c.), in thousand dry short tons, 

on forest land by owner category, softwood/hardwood 

species category, and tree component, Black Hills 

National Forest, 2011

Table 10.—Average annual net growth of growing-stock 

trees (at least 5 inches d.b.h.), in thousand cubic feet, 

on timberland by species group, species, and owner 

category, Black Hills National Forest, Wyoming 2000-

2005, South Dakota 2002-2006: 2007-2011

Table 11.—Average annual removals of growing-stock 

trees (at least 5 inches d.b.h.), in thousand cubic feet, 

on timberland by species group, species, and owner 

category, Black Hills National Forest, Wyoming 2000-

2005, South Dakota 2002-2006: 2007-2011

Table 12.—Average annual mortality of growing-stock 

trees (at least 5 inches d.b.h.), in thousand cubic feet, 

on timberland by species group, species, and owner 

category, Black Hills National Forest, Wyoming 2000-

2005, South Dakota 2002-2006: 2007-2011
30

Table 1.—Area of forest land, in thousand acres, by forest-type group, forest type, and owner category, Black Hills National Forest, 2011

Owner category 

Forest-type group/forest type All owners Public Private Unidentified owner

Softwood type groups

Spruce / fir group

White spruce 51.6 51.6 -- --

All forest types 51.6 51.6 -- --

Pinyon / juniper group

Rocky Mountain juniper 11.3 11.3 -- --

All forest types 11.3 11.3 -- --

Ponderosa pine group

Ponderosa pine 884.9 881.4 3.6 --

All forest types 884.9 881.4 3.6 --

All softwood groups 947.9 944.3 3.6 --

Hardwood type groups

Oak / hickory group

Bur oak 25.1 25.1 -- --

Mixed upland hardwoods 5.7 5.7 -- --

All forest types 30.8 30.8 -- --

Aspen / birch group

Aspen 83.8 83.8 -- --

Paper birch 5.3 5.3 -- --

Pin cherry 4.3 4.3 -- --

All forest types 93.4 93.4 -- --

Other hardwoods group

Other hardwoods 15.8 15.8 -- --

All forest types 15.8 15.8 -- --

All hardwood groups 140 140 -- --

Nonstocked 75.2 75.2 -- --

All forest groups 1,163.2 1,159.6 3.6 --

All table cells without observations in the inventory sample are indicated by --. Table value of 0.0 indicates the acres round to less than 0.1 thousand acres. Columns and rows 

may not add to their totals due to rounding.

Table 2.—Area of timberland, in thousand acres, by major forest-type group, stand origin, and owner category, Black Hills National Forest, 2011

Owner category 

Major forest-type group and stand origin All owners Public Private Unidentified owner

Softwood type groups

Natural 928.2 924.6 3.6 --

Planted 6.1 6.1 -- --

All softwood types 934.3 930.7 3.6 --

Hardwood type groups

Natural 128.7 128.7 -- --

Planted 5.7 5.7 -- --

All hardwood types 134.4 134.4 -- --

Nonstocked 70.1 70.1 -- --

All groups 1,138.7 1,135.2 3.6 --

All table cells without observations in the inventory sample are indicated by --. Table value of 0.0 indicates the acres round to less than 0.1 thousand acres. Columns and rows 

may not add to their totals due to rounding.
31

Table 3.—Area of timberland, in thousand acres, by forest-type group, forest type, and stand-size class, Black Hills National Forest, 2011

Stand-size class

Forest-type group/forest type All stands Sawtimber Poletimber Sapling-seedling Nonstocked

Softwood type groups

Spruce / fir group

White spruce 51.6 51.6 -- -- --

All forest types 51.6 51.6 -- -- --

Pinyon / juniper group

Rocky Mountain juniper 11.3 11.3 -- -- --

All forest types 11.3 11.3 -- -- --

Ponderosa pine group

Ponderosa pine 871.3 683.8 90.6 96.9 --

All forest types 871.3 683.8 90.6 96.9 --

All softwood groups 934.3 746.7 90.6 96.9 --

Hardwood type groups

Oak / hickory group

Bur oak 25.1 -- -- 25.1 --

Mixed upland hardwoods 5.7 -- -- 5.7 --

All forest types 30.8 -- -- 30.8 --

Aspen / birch group

Aspen 78.2 5.7 26.5 46.0 --

Paper birch 5.3 -- 5.3 -- --

Pin cherry 4.3 -- -- 4.3 --

All forest types 87.8 5.7 31.9 50.2 --

Other hardwoods group

Other hardwoods 15.8 -- -- 15.8 --

All forest types 15.8 -- -- 15.8 --

All hardwood groups 134.4 5.7 31.9 96.8 --

Nonstocked 70.1 -- -- -- 70.1

All forest groups 1,138.7 752.4 122.5 193.8 70.1

All table cells without observations in the inventory sample are indicated by --. Table value of 0.0 indicates the acres round to less than 0.1 thousand acres. Columns and rows 

may not add to their totals due to rounding.
32

Table 4.—Net volume of live trees (at least 5 inches d.b.h./d.r.c.), in thousand cubic feet, on forest land by species group, species, and owner category, 

Black Hills National Forest, 2011

Owner category

Species group/species All owners Public Private Unidentified owner

Softwoods

Ponderosa and Jeffery pines

Ponderosa pine 1,497,487 1,490,821 6,666 --

All species 1,497,487 1,490,821 6,666 --

Engelmann and other spruces

White spruce 66,650 66,650 -- --

All species 66,650 66,650 -- --

Woodland softwoods

Rocky Mountain juniper 5,815 5,815 -- --

All species 5,815 5,815 -- --

Total softwoods 1,569,953 1,563,287 6,666 --

Hardwoods

Cottonwood and aspen

Quaking aspen 21,383 21,383 -- --

All species 21,383 21,383 -- --

Other western hardwoods

Paper birch 4,467 4,467 -- --

Green ash 656 656 -- --

Eastern hophornbeam 175 175 -- --

Bur oak 7,284 7,284 -- --

American elm 281 281 -- --

All species 12,864 12,864 -- --

Total hardwoods 34,246 34,246 -- --

All species groups 1,604,199 1,597,533 6,666 --

All table cells without observations in the inventory sample are indicated by --. Table value of 0.0 indicates the acres round to less than 0.1 thousand acres. Columns and rows 

may not add to their totals due to rounding.

Table 5.—Net volume of live and salvable dead trees (at least 5 inches d.b.h./d.r.c.), in thousand cubic feet, on timberland by class of timber and 

softwood/hardwood species category, Black Hills National Forest, 2011

Class of timber All species Softwood species Hardwood species

Live trees

Growing-stock trees

Sawtimber

 Saw log portion 1,093,999 1,092,200 1,799

 Upper stem portion 182,432 181,762 670

 Total 1,276,431 1,273,961 2,470

Poletimber 235,971 215,817 20,154

All growing-stock trees 1,512,402 1,489,779 22,624

Cull trees

Rough treesa

 Sawtimber size 39,651 39,276 375

 Poletimber size 16,237 10,159 6,078

 Total 55,888 49,435 6,453

Rotten treesa

 Sawtimber size 3,320 2,049 1,271

 Poletimber size 1,312 -- 1,312

 Total 4,632 2,049 2,583

All live cull trees 60,520 51,484 9,036

All live trees 1,572,922 1,541,262 31,660

Salvable dead trees

Sawtimber size 45,982 45,982 --

Poletimber size 20,517 17,071 3,445

All salvable dead trees 66,498 63,053 3,445

All classes 1,639,420 1,604,315 35,105

All table cells without observations in the inventory sample are indicated by --. Table value of 0 indicates the volume rounds to less than 1 thousand cubic feet. Columns and 

rows may not add to their totals due to rounding.

a

Includes noncommercial species.
33

Table 6.—Net volume of growing-stock trees (at least 5 inches d.b.h./d.r.c.), in thousand cubic feet, on timberland by forest-type group, forest type, 

and softwood/hardwood species category, Black Hills National Forest, 2011

Forest-type group/forest type All species Softwood species Hardwood species

Softwood type groups

Spruce / fir group

White spruce 85,943 84,169 1,774

All forest types 85,943 84,169 1,774

Pinyon / juniper group

Rocky Mountain juniper 2,551 2,551 --

All forest types 2,551 2,551 --

Ponderosa pine group

Ponderosa pine 1,356,944 1,347,796 9,147

All forest types 1,356,944 1,347,796 9,147

All softwood groups 1,445,438 1,434,517 10,921

Hardwood type groups

Oak / hickory group

Bur oak 4,696 3,560 1,136

Mixed upland hardwoods 3,911 3,870 41

All forest types 8,607 7,430 1,177

Aspen / birch group

Aspen 41,533 32,234 9,300

Paper birch 2,104 1,223 882

Pin cherry 489 489 --

All forest types 44,127 33,946 10,181

Other hardwoods group

Other hardwoods 10,956 10,647 309

All forest types 10,956 10,647 309

All hardwood groups 63,690 52,023 11,668

Nonstocked 3,274 3,239 35

All forest groups 1,512,402 1,489,779 22,624

All table cells without observations in the inventory sample are indicated by --. Table value of 0.0 indicates the acres round to less than 0.1 thousand acres. Columns and rows 

may not add to their totals due to rounding.

Diameter class (inches at breast height)

Species group/species All classes 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+

Softwoods

Ponderosa and Jeffery pines

Ponderosa pine 1,432,614 48,433 156,770 219,402 235,267 235,013 201,322 162,759 97,222 76,427 --

All species 1,432,614 48,433 156,770 219,402 235,267 235,013 201,322 162,759 97,222 76,427 --

Engelmann and other spruces

White spruce 57,164 4,161 6,453 9,043 9,323 9,383 11,371 5,491 1,940 -- --

All species 57,164 4,161 6,453 9,043 9,323 9,383 11,371 5,491 1,940 -- --

Total softwoods 1,489,779 52,594 163,223 228,444 244,591 244,396 212,693 168,250 99,162 76,427 --

Hardwoods

Cottonwood and aspen

Quaking aspen 14,451 3,675 7,601 2,241 934 -- -- -- -- -- --

All species 14,451 3,675 7,601 2,241 934 -- -- -- -- -- --

Other western hardwoods

Paper birch 3,064 1,619 1,446 -- -- -- -- -- -- -- --

Green ash 532 -- 532 -- -- -- -- -- -- -- --

Bur oak 4,457 996 1,019 907 927 608 -- -- -- -- --

American elm 119 -- 119 -- -- -- -- -- -- -- --

All species 8,172 2,615 3,115 907 927 608 -- -- -- -- --

Total hardwoods 22,624 6,290 10,716 3,148 1,861 608 -- -- -- -- --

All species groups 1,512,402 58,884 173,939 231,592 246,452 245,005 212,693 168,250 99,162 76,427 --

All table cells without observations in the inventory sample are indicated by --. Table value of 0.0 indicates the acres round to less than 0.1 thousand acres. Columns and 

rows may not add to their totals due to rounding.

Table 7.—Net volume of growing-stock trees (at least 5 inches d.b.h./d.r.c.), in thousand cubic feet, on timberland by species group, species, and diameter class, 

Black Hills National Forest, 2011
34

Table 8a.—Net volume of sawtimber trees, in thousand board feet (International 1⁄4-inch rule), on timberland by species group, species, and diameter class, 

Black Hills National Forest, 2011

Diameter class (inches at breast height)

Species group/species All classes 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+

Softwoods

Ponderosa and Jeffery pines

Ponderosa pine 5,547,481 555,517 923,216 1,097,763 1,044,370 901,655 561,617 463,343 --

All species 5,547,481 555,517 923,216 1,097,763 1,044,370 901,655 561,617 463,343 --

Engelmann and other spruces 

White spruce 196,384 37,950 38,959 39,605 48,325 23,023 8,522 -- --

All species 196,384 37,950 38,959 39,605 48,325 23,023 8,522 -- --

Total softwoods 5,743,864 593,468 962,175 1,137,368 1,092,694 924,678 570,139 463,343 --

Hardwoods

Cottonwood and aspen

Quaking aspen 4,281 -- 4,281 -- -- -- -- -- --

All species 4,281 -- 4,281 -- -- -- -- -- --

Other western hardwoods

Bur oak 7,309 -- 4,398 2,911 -- -- -- -- --

All species 7,309 -- 4,398 2,911 -- -- -- -- --

Total hardwoods 11,590 -- 8,679 2,911 -- -- -- -- --

All species groups 5,755,454 593,468 970,854 1,140,278 1,092,694 924,678 570,139 463,343 --

All table cells without observations in the inventory sample are indicated by --. Table value of 0.0 indicates the acres round to less than 0.1 thousand acres. Columns and rows 

may not add to their totals due to rounding.

Table 8b.—Net volume of sawtimber trees, in thousand board feet (Scribner rule), on timberland by species group, species, and diameter class, 

Black Hills National Forest, 2011

Diameter class (inches at breast height)

Species group/species All classes 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+

Softwoods

Ponderosa and Jeffery pines

Ponderosa pine 4,803,253 434,970 765,069 941,551 917,375 806,530 509,892 427,866 --

All species 4,803,253 434,970 765,069 941,551 917,375 806,530 509,892 427,866 --

Engelmann and other spruces

White spruce 166,749 29,715 32,285 33,969 42,448 20,594 7,737 -- --

All species 166,749 29,715 32,285 33,969 42,448 20,594 7,737 -- --

Total softwoods 4,970,002 464,685 797,354 975,520 959,823 827,124 517,629 427,866 --

Hardwoods

Cottonwood and aspen

Quaking aspen 3,560 -- 3,560 -- -- -- -- -- --

All species 3,560 -- 3,560 -- -- -- -- -- --

Other western hardwoods

Bur oak 6,165 -- 3,658 2,506 -- -- -- -- --

All species 6,165 -- 3,658 2,506 -- -- -- -- --

Total hardwoods 9,725 -- 7,219 2,506 -- -- -- -- --

All species groups 4,979,727 464,685 804,573 978,027 959,823 827,124 517,629 427,866 --

All table cells without observations in the inventory sample are indicated by --. Table value of 0.0 indicates the acres round to less than 0.1 thousand acres. Columns and rows 

may not add to their totals due to rounding.
35

Table 9.—Aboveground dry weight of live trees (at least 1 inch d.b.h./d.r.c.), in thousand dry short tons, on forest land by owner category, softwood/hardwood 

species category, and tree component, Black Hills National Forest, 2011

Tree biomass component

Owner category and Growing-stock trees Non-growing-stock trees

softwood/hardwood All All live Stumps, tops, Stumps, tops,

Category Components 1-5 inch trees Total Boles and limbs Total Boles and limbs

Public

Softwoods 22,762 698 27,159 22,184 4,975 905 670 235

Hardwoods 1,379 602 549 381 168 228 157 71

Total 30,140 1,300 27,707 22,565 5,143 1,133 827 306

Private

Softwoods 121 -- 121 98 22 -- -- --

Total 121 -- 121 98 22 -- -- --

All ownerships

Softwoods 28,882 698 27,280 22,282 4,997 905 670 235

Hardwoods 1,379 602 549 381 168 228 157 71

Total 30,261 1,300 27,828 22,663 5,165 1,133 827 306

All table cells without observations in the inventory sample are indicated by --. Table value of 0.0 indicates the acres round to less than 0.1 thousand acres. Columns and rows 

may not add to their totals due to rounding.

Table 10.—Average annual net growth of growing-stock trees (at least 5 inches d.b.h.), in thousand cubic feet, on timberland by species group, species, and owner 

category, Black Hills National Forest, Wyoming 2000-2005, South Dakota 2002-2006: 2007-2011

Owner category

Species group/species All owners Public Private Unidentified owner

Softwoods

Ponderosa and Jeffery pines

Ponderosa pine 21,771 21,708 63 --

All species 21,771 21,708 63 --

Engelmann and other spruces

White spruce 1,074 1,074 -- --

All species 1,074 1,074 -- --

Total softwoods 22,845 22,782 63 --

Hardwoods

Cottonwood and aspen

Quaking aspen -546 -546 -- --

All species -546 -546 -- --

Other western hardwoods

Paper birch 23 23 -- --

Green ash 22 22 -- --

Bur oak 99 99 -- --

American elm 1 1 -- --

All species 144 144 -- --

Total hardwoods -402 -402 -- --

All species groups 22,444 22,381 63 --

All table cells without observations in the inventory sample are indicated by --. Table value of 0.0 indicates the acres round to less than 0.1 thousand acres. Columns and rows 

may not add to their totals due to rounding.
36

Table 11.—Average annual removals of growing-stock trees (at least 5 inches d.b.h.), in thousand cubic feet, on timberland by species group, species, and owner 

category, Black Hills National Forest, Wyoming 2000-2005, South Dakota 2002-2006: 2007-2011

Owner category

Species group/species All owners Public Private Unidentified owner

Softwoods

Ponderosa and Jeffery pines

Ponderosa pine 24,663 24,663 -- --

All species 24,663 24,663 -- --

Engelmann and other spruces

White spruce 1,712 1,712 -- --

All species 1,712 1,712 -- --

Total softwoods 26,375 26,375 -- --

Hardwoods

Cottonwood and aspen

Quaking aspen 12 12 -- --

All species 12 12 -- --

Total hardwoods 12 12 -- --

All species groups 26,387 26,387 -- --

All table cells without observations in the inventory sample are indicated by --. Table value of 0.0 indicates the acres round to less than 0.1 thousand acres. Columns and rows 

may not add to their totals due to rounding.

Table 12.—Average annual mortality of growing-stock trees (at least 5 inches d.b.h.), in thousand cubic feet, on timberland by species group, species, and owner 

category, Black Hills National Forest, Wyoming 2000-2005, South Dakota 2002-2006: 2007-2011

Owner category

Species group/species All owners Public Private Unidentified owner

Softwoods

Ponderosa and Jeffery pines

Ponderosa pine 14,046 14,046 -- --

All species 14,046 14,046 -- --

Engelmann and other spruces

White spruce 826 826 -- --

All species 826 826 -- --

Total softwoods 14,873 14,873 -- --

Hardwoods

Cottonwood and aspen

Quaking aspen 970 970 -- --

All species 970 970 -- --

Other western hardwoods

Paper birch 137 137 -- --

Bur oak 8 8 -- --

All species 146 146 -- --

Total hardwoods 1,115 1,115 -- --

All species groups 15,988 15,988 -- --

All table cells without observations in the inventory sample are indicated by --. Table value of 0.0 indicates the acres round to less than 0.1 thousand acres. Columns and rows 

may not add to their totals due to rounding.
Walters, Brian F.; Woodall, Christopher W.; Piva, Ronald J.; Hatfield, Mark A.; Domke, Grant 

M.; Haugen, David E. 2013. Forests of the Black Hills National Forest 2011. Resour. Bull. 

NRS-83. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern 

Research Station. 36 p.

This inventory of the Black Hills National Forest (BHNF) covers the years 2007-2011 on the 

South Dakota portion of the forest and 2005 on the Wyoming portion. It reports more than 

1.16 million acres of forest land dominated by ponderosa pine. Forest features reported 

on include volume, biomass, growth, removals, mortality, carbon, snags, and down woody 

material, along with information on forest economics. This report provides the public with a 

set of forest statistics that may be used in the Black Hills’ land management decisionmaking.

KEY WORDS: inventory, forest statistics, forest land, volume, biomass, carbon, growth, 

removals, mortality, forest health

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all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of 

program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice 

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14th and Independence Avenue, SW, Washington, DC 20250-9410, or call (202) 720-5964 (voice or TDD). USDA is an 

equal opportunity provider and employer.