BIA Forest Lands of

North and South

Dakota, 1996

David E. Haugen and Mark H. Hansen

Forest

Service

North Central

Research Station

Resource Bulletin

NC-202

United States

Department of

Agriculture
North Central Research Station

Forest Service—U.S. Department of Agriculture

1992 Folwell Avenue

St. Paul, Minnesota 55108

2002

www.ncrs.fs.fed.us
FOREWORD

Forest Inventory and Analysis (FIA) is a continuing endeavor as mandated by the Renewable

Resources Research Act of 1978. The objective of FIA is to periodically inventory the Nation’s

forest resources. Up-to-date resource information is essential to frame forest policies and

programs. U.S. Department of Agriculture, Forest Service regional research stations are

responsible for conducting these inventories and publishing summary reports for individual

States. The North Central Research Station is responsible for inventory and analysis in Illinois,

Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, South

Dakota, and Wisconsin.

Data used in this report were collected during the third North Dakota forest inventory, begun

in September 1994 and completed in November 1994, and the fourth South Dakota forest

inventory, begun in 1995 and completed in the spring of 1996. The reported statistics are

estimates. Users of these data are cautioned to consult the table of sampling errors and the

inventory methods section of the appendix. Fieldwork for these inventories was expedited

through the cooperation and assistance of the Bureau of Indian Affairs, U.S. Department of

the Interior.

The North and South Dakota inventories were directed by Neal Kingsley (retired), FIA Program

Manager, North Central Research Station, St. Paul, Minnesota. Robert Sienko, Bureau of

Indian Affairs, Billings, Montana, Area Office, coordinated the BIA’s participation.

St. Paul FIA office staff at the time were: Roger Audette, Gary Brand, Beth Collins, Barb

Fuller, Dan Goodman, Dale Gormanson, Dan Groen, Ron Hackett, Mark Hansen, David

Haugen, Doug Hecker, Jennifer Iole, Barb Johnson, Mike Johnson, Neal Kingsley, Barb

Knight, Leo Larkin, Earl Leatherberry, Joel Lemberg, Troy Lindgren, Doug Magee, Dennis

May, Pat Miles, Jerry Ostrom, Ron Piva, Gerhard Raile, Mary Jo Resendez, Thomas Schmidt,

Jay Solomakos, Dan Wendt, and Suzann Willhite.

FIA field crew members were: John Benaszeski, Avery Beyer, Nathan Goodrich, Gary

Inhelder, Lisa McDonald, Peter Koehler, Keith Magnusson, Mark Majewsky, Timothy Miller,

Daniel Nelson, Wilfred Ortiz, Paul Perdew, Daniel Sherrill, Gary Stachowicz, Kristen Weber,

and Chris Yonkers.
This report includes the most commonly used U.S. Department of Agriculture, Forest

Service, Forest Inventory and Analysis (FIA) statistics. Additional forest resource data can

be obtained through FIA staff, an FIA CD-ROM, or through a table generator on the North

Central Research Station's Internet page. Persons requesting additional information that

requires FIA staff time are expected to pay the retrieval costs. Requests for information

may be directed to:

Program Manager Bureau of Indian Affairs, USDI Billings Area Office

Forest Inventory and Analysis 316 North 26th Street

North Central Research Station Billings, MT 59101

1992 Folwell Avenue Phone: (406) 247-7943

St. Paul, MN 55108 FAX: (406) 247-7976

Phone: (651) 649-5139

FAX: (651) 649-5285
CONTENTS

Page

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

 Forest Area.................................................................................................. 2

 Forest Type Composition ............................................................................ 2

 Oak-Hickory .............................................................................................. 3

 Elm-Ash-Locust ........................................................................................ 3

 Aspen-Birch .............................................................................................. 3

 Elm-Ash-Cottonwood ............................................................................... 3

 Maple-Beech-Birch ................................................................................... 4

 Ponderosa Pine ........................................................................................ 4

 Stand-Size Classes ...................................................................................... 4

 Productivity of Timberland........................................................................... 5

 Stocking May Hold the Key to Improved Productivity on BIA

 Timberlands ............................................................................................. 5

 Number of Trees—North Dakota BIA .......................................................... 6

 Number of trees—South Dakota BIA .......................................................... 6

 Timberland Volume...................................................................................... 7

 Growing-Stock Volume............................................................................. 7

 Volume Per Acre ...................................................................................... 8

 Sawtimber ................................................................................................ 8

 Timber Quality ............................................................................................. 9

 Growth ....................................................................................................... 10

 Growing-Stock Growth............................................................................ 10

 Sawtimber Growth .................................................................................. 10

 Mortality ..................................................................................................... 11

 Mortality in Growing Stock...................................................................... 11

 Mortality in Sawtimber ............................................................................ 11

 Removals ................................................................................................... 11
Appendix ........................................................................................... 12

 Reliability of the Survey.............................................................................. 12

 Comparing the 1994 North Dakota and 1996 South Dakota

 Inventories with the 1980 Inventories in These Two States .................. 13

 Survey Procedures ..................................................................................... 13

 Statistical Design........................................................................................ 14

 Sample Based on the Remeasurement of the 1980 NCFIA Inventory ...... 14

 1980 NCFIA Inventory Aerial Photo Plots (Phase 1)................................... 14

 1980 NCFIA Inventory Ground Plots (Phase 2) .......................................... 14

 Remeasurement of the 1980 NCFIA Inventory.......................................... 15

 Sample Based on the NRCS-NRI ............................................................... 16

 Combined Estimate Based on the Two Independent Inventories .............. 17

 Field Measurements: 1980 Inventory Plot Design ..................................... 17

 Field Measurements: 1994-1996 Inventory Plot Design ............................ 18

 New Inventory Plots................................................................................... 18

 Old Inventory Plots..................................................................................... 18

 Computation of Estimates ......................................................................... 20

 Area ......................................................................................................... 20

 Volume .................................................................................................... 20

 Growth and Mortality .............................................................................. 20

 Average Annual Removals ...................................................................... 20

 Tree and Log Grades .................................................................................. 21

 Metric Equivalents ..................................................................................... 24

 Tree Species Groups in North and South Dakota ....................................... 25

 Definition of Terms ..................................................................................... 26

 Literature Cited .......................................................................................... 33

 Table Titles.................................................................................................. 34

 Tables ......................................................................................................... 36
About the Authors:

David E. Haugen is a

Forester and Mark H.

Hansen is a Research

Forester in the Forest

Inventory and Analysis

Program at the North

Central Research Station,

St. Paul, Minnesota.

BIA Forest Lands of North and

South Dakota, 1996

David E. Haugen and Mark H. Hansen

Note.—The forest land area in this report represents areas identified by the Bureau of

Indian Affairs (BIA) as “Tribal Trust Land” within the boundaries of reservations in the

States of North and South Dakota. Tribal Trust Lands outside of reservation boundaries,

individually owned trust lands, and government-owned lands were not included in this

report. This report contains information useful for identifying forestry related trends on trust

lands. Professionals with the Branch of Forest Resource Planning (BOFRP) within the

Forestry Division of the BIA can use this information in natural resource planning.

HIGHLIGHTS

• BIA forest lands in North Dakota and South

Dakota amounted to 146.1 thousand acres

of forest land, and 131.3 thousand acres of

this land were classified as timberland.

• In addition to the forest land area, BIA

lands have 56.9 thousand acres of

nonforest land with trees. Nonforest land

with trees includes wooded strips, farm

and field windbreaks, wooded pastures,

and abandoned cropland.

• Aspen-birch is the most extensive forest

type found on North Dakota BIA timberlands, accounting for more than 57

percent, or 22.4 thousand acres of timberland. Ponderosa pine is the most extensive

forest type found on South Dakota BIA

timberlands, accounting for more than 44

percent, or 41.3 thousand acres of timberland.

• Even with the prevalence of adverse

growing conditions in North and South

Dakota, over a fifth of BIA timberlands are

capable of growing more than 50 cubic feet

of wood per acre per year.

• Growing-stock volume on North Dakota

BIA timberlands was 21 million cubic feet

in 1994 and represented 6 percent of the

State’s total volume. Growing-stock volume

on South Dakota BIA timberlands was 62.6

million cubic feet in 1996 and represented

14 percent of the State’s total volume

outside of the Black Hills National Forest.

• Sawtimber volume in 1994 stood at 30.1

million board feet on North Dakota BIA

timberlands and at 264.5 million board feet

on South Dakota BIA timberlands in 1996.

• Eighty-six percent of the total sawtimber

volume found on North Dakota BIA

timberlands came from aspen, bur oak, and

balsam poplar species groups. On South

Dakota timberlands, 88 percent of the total

sawtimber volume came from ponderosa

pine and cottonwood species groups.

• An average of 1.7 million cubic feet of net

growth of growing stock was added to BIA

timberlands per year between 1980 and

1995. In North Dakota, this translates to an

estimated 17.6 cubic feet per acre of

average annual net growth on BIA timberlands. On South Dakota BIA timberlands,

annual net growth averaged 16.5 cubic feet

per acre per year.
• On a per acre basis, growing-stock

mortality averaged 8.8 cubic feet per acre

per year from 1980 to 1995 on BIA

timberlands. Thus, nearly 41 percent of the

annual gross growth of growing stock was

lost to mortality.

• Average annual removals of growing stock

between 1980 and 1995 was 1.1 cubic feet

per acre per year.

• BIA forests provide food, cover, and

protection for a vast array of wildlife

species from elk to turkey. In addition, they

improve water quality and control

streambank erosion and sedimentation.

FOREST AREA

In 1994, BIA lands in North Dakota were

estimated at 246 thousand acres, and 48

thousand acres or 20 percent were forested. In

1996, South Dakota BIA lands were estimated

at 2.6 million acres of which 99 thousand

acres or 4 percent were forested. Total area of

timberland on BIA land was estimated at 39

thousand acres in North Dakota and 93

thousand acres in South Dakota. Woodland

area on BIA lands was estimated at 9 thousand

acres for North Dakota and 6 thousand acres

for South Dakota.

Land classified as nonforest with trees was

estimated at 5 thousand acres on BIA lands in

North Dakota in 1994 and at 52 thousand

acres on BIA lands in South Dakota in 1996.

Examples of nonforest land with trees would

include windbreaks, wooded strips, improved

pastures with trees, and wood pastures.

Typically, nonforest land with trees offers few

possibilities for commercial use. However,

such land does offer many benefits including

soil erosion control (improved water quality),

rural buildings and land protection (improved

quality of life), shade for livestock, and shelter

and food for wildlife.

FOREST TYPE COMPOSITION

Hardwood forest types dominate the forest

landscape on North Dakota BIA timberlands.

In fact, only three forest types were recorded

during the inventory on BIA timberlands in

North Dakota: aspen-birch, oak-hickory, and

elm-ash-locust (fig. 1). South Dakota BIA

timberlands have a mix of softwood and

hardwood forest types (fig. 2). Softwood forest

types found during the 1996 inventory were

ponderosa pine and Rocky Mountain juniper.

Hardwood forest types included oak-hickory,

elm-ash-locust, elm-ash-cottonwood, and

maple-beech-birch.

Figure 1.—Percent of area by

forest type, North Dakota

BIA, 1994.

2

Bur oak

33%

Aspen-birch

58%

Elm-ash

9%
Figure 2.—Percent of area by

forest type, South Dakota

BIA, 1996.

Oak-Hickory

The oak-hickory forest type occupied 12.8

thousand acres or 33 percent of the total BIA

timberlands in North Dakota and 21.2

thousand acres or 23 percent of the total BIA

timberlands in South Dakota. Because bur oak

is the only native oak species found in North

and South Dakota, the local type is called bur

oak. Species commonly associated with the

bur oak forest type in North and South

Dakota are basswood and green ash.

Elm-Ash-Locust

In the most recent inventory, the elm-ashlocust forest type occupied 3.6 thousand acres

or 9 percent of the total BIA timberlands in

North Dakota and 12.8 thousand acres or 14

percent of total BIA timberlands in South

Dakota. The local forest type is called elm-ash,

an upland forest type dominated by American

elm and green ash.

Aspen-Birch

The aspen-birch forest type occupied 22.4

thousand acres or 58 percent of the total BIA

timberlands in North Dakota. The entire State

of North Dakota has 117.8 thousand acres of

aspen-birch forest type, which means that 19

percent of all aspen-birch forest land in the

entire State is found on North Dakota BIA

timberlands.

Elm-Ash-Cottonwood

The elm-ash-cottonwood forest type, a lowland

forest type, occupied 11.2 thousand acres or

12 percent of the total BIA timberlands in

South Dakota. The elm-ash-cottonwood forest

type can be broken down into three local forest

type groups, which are cottonwood (6.7

thousand acres), elm-ash-cottonwood (2.4

thousand acres), and willow (2.1 thousand

acres). A major forestry concern in the Plains

States is the lack of cottonwood regeneration.

Two major factors contributing to this problem

are the construction of flood control dams on

major rivers and streams and the grazing of

livestock in riparian areas. Cottonwood seeds

require a nearly bare mineral soil seedbed to

germinate. Frequent flooding along the

streambanks helps prepare a suitable seedbed

for germination. Reduced periodic flooding

has decreased the availability of bare mineral

soils for cottonwood seeds to germinate

(Haugen et al. 1999).

Rocky Mountain

juniper

2%

Ponderosa 

pine

45%

Elm-ashcottonwood

12%

Elm-ash

14%

Basswood 

4%

Bur oak

23%

3
Maple-Beech-Birch

In 1996, the maple-basswood forest type (local

forest type) occupied 3.9 thousand acres or 4

percent of BIA timberland in South Dakota.

The entire State of South Dakota has only 5

thousand acres of this type, which means that

78 percent of this particular forest type is

found on BIA timberlands.

Ponderosa Pine

In 1996, the ponderosa pine forest type

occupied 41.3 thousand acres or 45 percent of

Figure 3.—Area of timberland by forest type group/local type and

stand-size class, North Dakota BIA, 1994.

Figure 4.—Area of timberland by forest type group/local type and stand-size class,

South Dakota BIA, 1996.

BIA timberland in South Dakota. Much of this

forest type was found on the Pine Ridge

Reservation.

STAND-SIZE CLASSES

Stand-size class is a classification of stocked

forest land based on the size class of live trees

on the area: sawtimber, poletimber, and

sapling and seedlings (figs. 3 and 4).

4

0 5 10 15 20 25

Bur oak

Aspen-birch

Elm-ash

Forest type

Thousand acres

Sapling-Seedling Poletimber Sawtimber

0 10 20 30 40 50

Ponderosa pine

Rocky Mountain juniper

Bur oak

Elm-ash-cottonwood

Basswood

Elm-ash

Forest type

Thousand acres

Sapling-Seedling Poletimber Sawtimber
PRODUCTIVITY OF

TIMBERLAND

BIA forest lands are productive: 80 percent of

all BIA forest lands in North Dakota and 94

percent of all BIA forest lands in South Dakota

have the potential to annually produce 20 or

more cubic feet of wood per acre per year. The

forest land area can be divided into two major

land-use classes: timberland and woodland.

North Dakota BIA forest land consists of 38.8

thousand acres of timberland and 8.8

thousand acres of woodland. South Dakota

BIA forest land consists of 92.5 thousand acres

of timberland and 6 thousand acres of

woodland.

On BIA timberlands, potential productivity

class is used to evaluate timberland site

quality as related to potential timber production. Potential productivity is expressed in

cubic feet of net growth per acre per year on a

given site. Productivity on BIA timberlands in

North and South Dakota is lower than in

other regions due in part to extreme weather

conditions, including drought, strong winds,

and widely varying seasonal temperatures.

Only 4 percent of BIA timberland in North

Dakota has the potential to produce more

than 85 cubic feet per acre per year of growth

and less than 1 percent of BIA timberland in

South Dakota can produce this much. Another

37 percent of the BIA timberland in North

Dakota has the potential to produce between

50 and 84 cubic feet per acre per year of

growth, compared to an average of 22 percent

for the entire State. Only 14 percent of South

Dakota BIA timberland has the potential to

produce between 50 and 84 cubic feet per

acre per year. Most timberland, 86 percent on

South Dakota BIA land and 59 percent on

North Dakota BIA land, has the potential to

produce less than 50 cubic feet of growth per

acre per year.

STOCKING MAY HOLD THE

KEY TO IMPROVED

PRODUCTIVITY ON BIA

TIMBERLANDS

Stocking is an estimate of occupancy of a given

site, usually measured by basal area or number

of live trees required to fully utilize the growth

potential of the land. In North Dakota, 40

percent of BIA timberland area is either

nonstocked or poorly stocked (fig. 5), while in

South Dakota, 75 percent of BIA timberland

area is either nonstocked or poorly stocked

(fig. 6). In comparison, 53 percent of total

timberland area in North Dakota and 58

percent in South Dakota is poorly stocked or

nonstocked. Another 30 percent of the BIA

timberland area in North Dakota and 20

percent of BIA timberland area in South

Dakota is moderately stocked. If stocking is

increased even to moderate stocking levels on

poor sites, growth will increase and the

potential of timberland to grow and hold more

wood fiber should be realized.

5

Figure 5.—Percent of

timberland by stocking class

of growing-stock trees,

North Dakota BIA, 1994.

Figure 6.—Percent of

timberland by stocking class

of growing-stock trees,

South Dakota BIA, 1996.

Non-stocked

6%

Poorly Stocked

34%

Moderately stocked

30%

Fully stocked

30%

Poorly Stocked

65%

Moderately stocked

20%

Fully stocked

5%

Non-stocked

10%
NUMBER OF TREES—NORTH

DAKOTA BIA

In 1994, an estimated 22 million live trees 1

inch or greater d.b.h. were growing on 38.8

thousand acres of North Dakota BIA timberlands, an average of 568 trees per acre. Aspen,

green ash, and bur oak were the dominant

species with 39, 19, and 16 percent of the

NUMBER OF TREES—SOUTH

DAKOTA BIA

In 1996, an estimated 28 million live trees 1

inch or greater d.b.h. were growing on 92.5

thousand acres of South Dakota BIA timberlands, an average of 298 trees per acre.

Ponderosa pine, green ash, and bur oak were

total number of live trees, respectively (fig. 7).

Of the total number of live trees, growingstock trees (a live tree of commercial species

that meets specified standards of size, quality,

and merchantability) accounted for an

estimated 17 million trees, or 77 percent of all

live trees. Noncommercial tree species, which

include eastern hophornbeam (ironwood),

wild plum, and peachleaf willow, accounted

for 3 million or 14 percent of all live trees.

the dominant species with 43, 12, and 11

percent of the total number of live trees,

respectively (fig. 8). Of the total number of live

trees, growing-stock trees accounted for an

estimated 20 million trees, or 72 percent of all

live trees. Noncommercial tree species, which

include apple, wild plum, and peachleaf willow,

accounted for 4 million, or 14 percent of all

live trees.

Figure 8.—Number of all

live trees on timberland by

species group, South

Dakota BIA, 1996.

Figure 7.—Number of all

live trees on timberland by

species group, North

Dakota BIA, 1994.

6

0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

Ponderosa pine

Noncommercial species

Green ash

Bur oak

Other softwoods

Other hardwoods

Basswood

Cottonwood

Species group

Thousands of trees

0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000

Quaking aspen

Green ash

Bur oak

Noncommercial species

Other hardwoods

Balsam poplar

Elm

Species group

Thousands of trees
TIMBERLAND VOLUME

Growing-Stock Volume

Growing-stock volume was estimated at 21

million cubic feet on North Dakota BIA

timberland and at 63 million cubic feet on

South Dakota BIA timberland. On North

Dakota BIA timberland, 90 percent of all

growing-stock volume was contained in three

species: quaking aspen, bur oak, and balsam

poplar (fig. 9). On South Dakota BIA timberland, more than 79 percent of all growingstock volume was contained in two species:

ponderosa pine and cottonwood (fig. 10).

Figure 9.—Net volume of

growing stock on timberland

by species group, North

Dakota BIA, 1994.

Figure 10.—Net volume of

growing stock on

timberland by species

group, South Dakota BIA,

1996.

7

0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000

Ponderosa pine

Bur oak

Basswood

Elm

Green ash

Cottonwood

Other hardwoods

Species group

Thousand cubic feet

0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

Bur oak

Basswood

Elm

Green ash

Balsam poplar

Quaking aspen

Boxelder

Species group

Thousand cubic feet
Volume Per Acre

Growing-stock volume per acre averaged 542

cubic feet on North Dakota BIA timberland,

and 678 cubic feet on South Dakota BIA

timberland. The aspen-birch forest type had

the highest average for growing-stock volume

per acre in North Dakota BIA in 1994 with

678 cubic feet per acre. On South Dakota BIA

timberland, the cottonwood forest type had

the highest average for growing-stock volume

per acre with 1,140 cubic feet per acre. Other

forest types with above average volume per

acre on South Dakota BIA timberland were

basswood (925 cubic feet per acre), elm-ash

(914 cubic feet per acre), and elm-ashcottonwood (707 cubic feet per acre). The

willow forest type had the lowest per acre

volume with 158 cubic feet per acre.

Sawtimber

Sawtimber volume was estimated at 30 million

board feet on North Dakota BIA timberlands

and at 234 million board feet on South Dakota

BIA timberlands. Quaking aspen, bur oak, and

balsam poplar represented 86 percent of the

total sawtimber volume on North Dakota BIA

timberlands (fig. 11). On South Dakota BIA

timberlands, 88 percent of the total sawtimber

volume came from two species: ponderosa

pine and cottonwood (fig. 12).

Figure 11.—Net volume of

sawtimber on timberland by

species group, North Dakota

BIA, 1994.

Figure 12.—Net volume of

sawtimber on timberland by

species group, South

Dakota BIA, 1996.

8

0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000

Bur oak

Basswood

Elm

Green ash

Balsam poplar

Quaking aspen

Boxelder

Species group

Thousand board feet

0 20,000 40,000 60,000 80,000 100,000 120,000 140,000 160,000

Ponderosa pine

Bur oak

Basswood

Elm

Green ash

Cottonwood

Other hardwoods

Species group

Thousand board feet
TIMBER QUALITY

As a measure of timber quality, field crews

assigned log grades to softwood sawtimber

trees and they assigned tree grades to hardwood sawtimber trees. In the Dakotas, the

most critical factor in determining grade is the

d.b.h. of the tree. On North Dakota BIA

timberlands, 84 percent of the hardwood

sawtimber was given a tree grade of 3 or

poorer (fig. 13). The bur oak species had more

than 81 percent of its volume in sawtimber

less than 15 inches d.b.h. and 92 percent of

its volume in grades 3 or poorer. On South

Figure 13.—Quality of

sawtimber by tree grade,

North Dakota BIA, 1994.

Figure 14.—Quality of

sawtimber by tree grade,

South Dakota BIA, 1996.

9

Dakota BIA timberlands, ponderosa pine

(softwood species) had 96 percent of its

sawtimber volume in log grade 3; hardwood

species had 39 percent of their sawtimber

volume in tree grades 3 or poorer. Combined,

all softwood and hardwood tree species in

South Dakota BIA had 72 percent of their

sawtimber volume in grades 3 or poorer (fig.

14). Three species—cottonwood, bur oak, and

basswood—accounted for 61 percent of the

sawtimber volume in tree grades 1 and 2;

cottonwood accounted for 86 percent of the

total volume in tree grades 1 and 2.

Tree 

grade 1 —

8%

Tree 

grade 2—

8%

Tree 

grade 3—

43%

Tree 

grade 4—

41%

Tree

grade 3—

68% Tree 

grade 1—

19%

Tree

grade 2—

9%

Tree 

grade 4—

4%
GROWTH

Growing-Stock Growth

An average of 1.7 million cubic feet of net

growth of growing stock was added to BIA

timberlands per year between 1980 and 1995

(fig. 15). In North Dakota, this translates into

an estimated 17.6 cubic feet per acre of

average annual net growth on BIA timberlands. The average annual growth rate on

North Dakota BIA timberland is about 3

percent of the total growing-stock inventory.

The aspen-birch forest type on North Dakota

BIA timberlands accounted for 87 percent of

the average net growth between 1980 and

1993. On South Dakota BIA timberlands,

average annual net growth per acre is estimated at 10.5 cubic feet per year. The average

annual growth rate on these lands is about 2

percent of the total growing-stock inventory.

The ponderosa pine forest type accounted for

46 percent of the average annual net growth

between 1980 and 1995.

Figure 15.—Average annual net growth, mortality, removals of growing stock

on timberlands, North Dakota BIA, 1980-1993, and South Dakota BIA, 1980-

1995.

10

Sawtimber Growth

The average annual net growth of sawtimber

between 1980 and 1995 was estimated at 850

thousand board feet for BIA timberlands in

North Dakota and 3.0 million board feet on

BIA timberlands in South Dakota per year (fig.

16). This averages out to be 22 board feet per

acre per year of growth on North Dakota BIA

timberland and 33 board feet per acre per year

of growth on South Dakota BIA timberland. An

estimated 98 percent of the average annual net

growth of sawtimber came from the aspenbirch forest type on BIA timberlands in North

Dakota. A little over 60 percent of the average

annual net growth of sawtimber came from the

ponderosa pine forest type on South Dakota

BIA timberlands. The other major forest types

contributing to average annual net growth of

sawtimber on South Dakota BIA timberlands

were elm-ash-cottonwood with 21 percent and

oak-hickory with 16 percent.

Figure 16.—Average annual net growth, mortality, and removals of sawtimber

on timberland, North Dakota BIA, 1980-1993, and South Dakota BIA, 1980-

1995.

0

1000

2000

3000

4000

5000

North Dakota South Dakota Total

Forest Survey Units

Thousand board feet

Growth Mortality Removals 

0

200

400

600

800

1000

1200

1400

1600

1800

North Dakota South Dakota Total

BIA Suvey Units

Thousand cubic feet

Growth Mortality Removals 
MORTALITY

Mortality in Growing Stock

Average annual mortality for growing stock on

BIA timberlands in North and South Dakota

was estimated at 1.2 million cubic feet between

1980 and 1995. Average annual mortality as a

percentage of total volume was 2 percent of the

total growing-stock volume on North Dakota

BIA timberlands and 1 percent of the total

growing-stock volume on South Dakota BIA

timberlands. On North Dakota BIA timberlands, average annual mortality equaled 11

cubic feet per acre per year between 1980 and

1993. On South Dakota BIA timberlands,

average annual mortality equaled 8 cubic feet

per acre per year between 1980 and 1995.

Quaking aspen made up 67 percent of the

growing-stock average annual mortality on

North Dakota BIA timberlands, followed by

balsam poplar with 19 percent of the mortality

and elm with 12 percent. On South Dakota BIA

timberlands, cottonwood made up 40 percent

of the growing-stock average annual mortality,

followed by ponderosa pine with 27 percent of

the mortality and elm with 13 percent.

Mortality in Sawtimber

Average annual sawtimber mortality was 721

thousand board feet on North Dakota BIA

timberlands and 2.7 million board feet on South

Dakota BIA timberlands. Aspen accounted for

more than half (383 thousand board feet) of all

sawtimber mortality on North Dakota BIA

timberlands. Cottonwood accounted for 46

percent or 1.2 million board feet of all sawtimber mortality on South Dakota BIA timberlands.

REMOVALS

Average annual growing-stock removals for

North and South Dakota BIA timberlands

between 1980 and 1995 was 54 and 89

thousand cubic feet, respectively. This averages

out to be 0.3 percent of the growing-stock

volume for North Dakota BIA and 0.1 percent of

the growing-stock volume for South Dakota BIA

timberlands. Quaking aspen accounted for 69

percent of growing-stock removals on North

Dakota BIA timberlands, and green ash and elm

accounted for 75 percent of growing-stock

removals on South Dakota BIA timberlands.

In 1994, the aspen-birch forest type accounted

for 58 percent of North Dakota BIA timberland

area and all of the average annual growing-stock

removals. The elm-ash-cottonwood forest type,

which accounted for 12 percent of South Dakota

BIA timberland area, had the highest amount of

average annual growing-stock removals with 74

percent of the total.

11
APPENDIX

RELIABILITY OF THE SURVEY

Forest Inventory and Analysis information is based on a sampling procedure designed to provide

reliable statistics at the State level. Consequently, the reported figures are estimates only. A measure

of reliability of these figures is given by sampling errors (table A). These sampling errors mean that

the chances are two out of three that if a 100-percent inventory had been made, using the same

methods, the results would have been within the limits indicated.

For example, the estimated growing-stock volume in BIA timberlands was 83.7 million cubic feet,

with a sampling error of ± 8.5 percent (± 7.1 million cubic feet). The growing-stock volume from a

100-percent inventory would be expected to fall between 90.8 million cubic feet and 76.6 million

cubic feet (83.7 ± 7.1), there being a one in three chance that this is not the case.

Table A.—Sampling errors for the 1994 and 1996 inventories of North and South

Dakota’s BIA timberlands

Item BIA totals Sampling error

Growing stock Million cubic feet Percent

 Volume (1994/1996) 83.7 8.5

 Average annual growth

 (1980-1993/1980-1995) 1.7 15.0

 Average annual removals

 (1980-1993/1980-1995) 0.1 67.8

Sawtimber Million board feet

 Volume (1994/1996) 264.6 11.9

 Average annual growth

 (1980-1993/1980-1995) 3.9 21.9

 Average annual removals

 (1980-1994/1980-1996) 0.3 69.0

Thousand acres

Timberland area (1994) 131.3 6.4

12
As survey data are broken down into sections

smaller than BIA totals, the sampling error

increases. For example, the sampling error for

volume for a species group is higher than that

for total volume on BIA timberland. To estimate

sampling error for data smaller than BIA totals,

use the following formula:

E = (SE) (BIA total volume or area)

(Volume or area smaller than BIA total)

Where :

E = Sampling error in percent.

SE = BIA total error for volume or area.

For example, to compute the error on the

growing-stock volume in the bur oak species

group for North Dakota BIA timberlands,

proceed as follows:

1) Total bur oak GS Volume (North Dakota

BIA) = 3,792 thousand cubic feet.

2) Total BIA GS Volume = 83,705 thousand

cubic feet.

3) The BIA total error for GS Volume = 8.5

percent.

4) Using the above formula:

0.085 83,705

3,792

E =

E = 39.9 percent sampling error for the bur oak

species group in North Dakota BIA timberland.

Sampling errors for area, volume, growth, and

removals, for both growing stock and sawtimber, by BIA sampling units are shown in table

17.

COMPARING THE 1994

NORTH DAKOTA AND

1996 SOUTH DAKOTA

INVENTORIES WITH THE

1980 INVENTORIES IN

THESE TWO STATES

All volumes and biomass estimates presented

in this report are based on methods presented

in Hahn and Hansen (1984). A different

volume estimation procedure developed for

Minnesota’s prairie region was used to compute

the volumes published in the 1980 inventory

reports. The newer methods were used to

recompute the 1980 inventories where

comparisons are presented in this report.

Although the adjustment will differ by species,

the recomputed 1980 growing-stock and

sawtimber volumes will generally be greater

than those shown in the 1980 report.

Past surveys used only growing-stock trees to

determine stand-size class. Current survey

procedures require that stand-size class be

determined on the basis of all live trees.

Therefore, direct comparisons of current

inventory data to old inventory data by standsize class may be misleading.

SURVEY PROCEDURES

The inventory of BIA lands in North and South

Dakota was part of the statewide inventories of

the two States, which sampled all forest lands

across both States, without regard to ownership. The North Dakota inventory covered all

lands in the State and the South Dakota

inventory covered all lands in the State outside

the Black Hills National Forest. The Black Hills

National Forest was inventoried at a different

time. The BIA provided additional funding to

the Forest Service to measure more plots

within all reservations in these two States. The

inventory was designed to provide statewide

information, but the intensified sampling

13
allows a breakdown of this information for BIA

lands. A summary of the procedures used in

these two statewide inventories is presented

here with references to the intensification on

BIA lands. This summary consists of three

parts:

1) A description of the statistical design used

in the inventory, which deals with the

methods used for stratification, aerial photo,

and ground plot selection and estimation.

2) A description of the ground plot measurements which focuses on the plot design and

changes in the design between the 1980

and the 1994-1996 inventories.

3) A description of the methods used to

compute items presented in this report

(area, number of trees, volume, growth,

mortality, removals, and biomass) from field

plot measurements.

STATISTICAL DESIGN

The basic design for this inventory consists of

two independent samples that were combined

to provide an overall estimate of the forest resources of the Dakotas. The first sample is

based on the remeasurement of the 1980

NCFIA inventory, and the second sample is

based on the Natural Resource Conservation

Service’s Natural Resources Inventory (NRCSNRI). These samples produced two independent estimates of the total forest resource in the

two States and were combined, using statistically appropriate methods, to provide the best

overall estimates possible.

SAMPLE BASED ON THE

REMEASUREMENT OF THE

1980 NCFIA INVENTORY

The first sample was based on the remeasurement of aerial photo and ground

plots taken during the 1980 NCFIA inventories

of North and South Dakota. These inventories

used double (two phase) sampling for stratification as presented in various texts on sampling

such as Cochran (1977) and Loetsch and Haller

(1964). Aerial photo plots were observed in the

first phase and ground measurement or field

plots were measured in the second phase.

1980 NCFIA INVENTORY

AERIAL PHOTO PLOTS

(PHASE 1)

The first phase of the 1980 inventory was a

systematic sample of aerial photo plots

distributed over the entire State. Sampling was

completed using a grid at the intensity of 121

photo plots per township (6 miles by 6 miles).

This provided a phase 1 sampling rate of one

photo plot per 190.4 acres. Each photo sample

plot was classified as forest, nonforest, questionable (samples where the photo interpreter

was unable to make a definite call between

forest and nonforest), or unproductive. The

distribution of photo plots by aerial photo

classification in the 1980 NCFIA forest

inventory is shown in table B.

1980 NCFIA INVENTORY

GROUND PLOTS (PHASE 2)

A systematic sample of the aerial photo plots

was selected as ground plots in phase 2 of the

1980 inventory. Within the two States, a total

of 24,446 ground plots were selected from the

478,210 photo plots. These ground plot

locations were carefully examined stereoscopically, pin pricked on the aerial photo, and

assigned a ground plot identification number.

Ground plots that definitely were not forest

land were given a nonforest ground land-use

classification (more detailed than the photo

classification done on all photo plots) by the

photo interpreter and not sent to the field for

measurement. These plots are referred to as

office ground plots. Ground plot locations that

could possibly be forest land (those classified as

forest, questionable, or unproductive) were

14
North Dakota South Dakota Both States,

statewide inventory BIA lands

inventory outside BHNF only

Forest 2,848 4,222 992

Questionable 247 530 109

Unproductive 401 59 65

Nonforest 223,397 246,506 65,965

 Total 226,893 251,317 67,131

Table B.—Number of aerial photo plots in the 1980 inventory of North

and South Dakota

Table C.—Number of ground plots in the 1980 inventory of North

and South Dakota

North Dakota South Dakota Both States,

statewide inventory BIA lands

inventory outside BHNF only

Forest 219 429 91

Questionable 19 75 13

Unproductive 31 8 5

Nonforest 17,183 6,085 3,266

 Total 17,452 6,597 3,375

Estimates of the forest resources presented in

1980 inventory reports are based on double

sampling for stratification based on these four

strata.

REMEASUREMENT OF THE

1980 NCFIA INVENTORY

The aerial photo classification completed in

the 1980 inventory was used for stratification

in the first sample of the 1994-1996 North and

South Dakota forest resources inventory. These

478,210 photo plots were used as the phase 1

sample to estimate the area in each of the four

strata. The second phase used plots that were

visited by field crews to sample and observe

ground conditions (land use, volume, growth,

mortality, removals, etc.) within the four strata.

The 1980 ground plots measured in the field

form the second phase of this sample. In the

forest, questionable, and unproductive strata,

remeasurement observations of every systematic ground plot location established during the

1980 inventory were used to estimate average

ground conditions within each strata in 1994.

In the nonforest stratum, a cluster sampling

scheme (using townships as clusters) was used

to make repeated ground observations of the

photo plots established in the 1980 inventory.

This sampling scheme was selected to improve

our ability to estimate the area of forest, with

particular emphasis on estimating the actual

area of land change to and from forest. Because

15

sent to the field for ground classification. The

ground plot sampling intensity varied by

inventory unit and was as low as one ground

plot per 2,541 acres in North Dakota and as

high as one ground plot per 6,892 in eastern

South Dakota. The distribution of ground plots

by aerial photo classification in the 1980

NCFIA inventory is shown in table C.
all stratification was based on the same photo

classification used in the previous inventory,

estimates of change in forest area cannot be

biased by differences in the quality of the aerial

photography, the equipment and techniques

used, and the individual photo interpreters and

their skills. This design maintained the same

level of intensity as the previous inventory in

the strata where most of the forest land was

found in the 1980 inventory (the forest and

questionable strata) and in those strata from

which most of the additional forest land was

anticipated to come (the unproductive stratum). The photo plots that were classified as

nonforest in the 1980 inventory were, by far,

the largest portion of the 1980 photo sample.

In addition, on a plot by plot basis, this stratum

was anticipated to have a low probability of

currently being forest. Cluster sampling

provided an efficient sample of this large area

with a low probability of change, by examining

a large number of locations at two points in

time.

Where double sampling was used in the forest,

questionable, and unproductive classifications,

the ground plot sampling intensity was one

plot per 2,876 acres in North Dakota and one

plot per 1,774 acres in South Dakota. In the

nonforest stratum where cluster sampling was

used, 155 townships from the total of 3,902

townships in the region were sampled. The

ground plot intensity in this region for the

nonforest without tree stratum was 9,427 acres

per plot. On BIA lands, additional new plots

were established at existing aerial photo plots

to approximately double the ground plot

intensity.

Every ground plot in the 1994 inventory was

classified for disturbance and other changes

that may have taken place between 1980 and

1994. Disturbed plots are those plots that

showed evidence of harvesting, insect or

disease damage, land-use change, or other

significant changes since the last inventory. A

subset of the undisturbed forest ground plots

was not remeasured. Instead, these plots were

updated using the Stand and Tree Evaluation

Modeling System (STEMS) (Belcher et al.

1982). The undisturbed forest plots that were remeasured were used to adjust the STEMS

model for discrepancies between updated and

actual remeasurements using methods presented in Hansen (1990) that have been used

in the previous NCFIA inventories in Michigan,

Minnesota, Iowa, Missouri, and Wisconsin. The

undisturbed forest plots that were not remeasured are referred to as pseudo-remeasurement plots because they contain all the data

normally collected on a remeasure-ment plot

(new plot and tree level data) but without the

expense of a field visit. This methodology has

been very efficient in other States inventoried

by NCFIA. Because these undisturbed forest

plots were not remeasured, other resources

were available to establish additional ground

plots for the second inventory based on the

NRCS-NRI.

SAMPLE BASED ON THE

NRCS-NRI

Just before this inventory, the Natural Resources Conservation Service (NRCS) conducted its National Resources Inventory (NRI)

in the Plains States (U.S. Department of

Agriculture, Soil Conservation Service 1991)

using a two-stage sampling design. This sample

design consisted of 160-acre and 640-acre

primary sampling units (PSU) with three 2-acre

secondary sampling units (SSU) located within

the PSUs. The NRCS-NRI inventory sampled all

lands except those owned by the Federal

government. Estimates of the 1994 forest resources on Federal lands (primarily Forest

Service, Corps of Engineers, and Bureau of

Indian Affairs lands) come entirely from the

NCFIA inventory described in the previous

section. The data collected in the NRI formed

the basis for stratification of the second

independent inventory.

This second portion of the overall inventory of

the North and South Dakota forest resources

used the NRCS-NRI area estimates and point

data as its basis for stratification and ground

plot location in a double sampling scheme

similar to the first portion of the inventory (the

NCFIA remeasurement of the 1980 field

ground plots). The number of 2-acre SSU plots

sampled by NRCS-NRI are shown in table D.

16
Table D.—Number of NRI-SSU plots available for remeasurement in the inventory of North

and South Dakota

NCFIA photo classified and installed standard

NCFIA field ground plots on a subset of the

NRI-SSU plot locations. The selection criteria

used resulted in a random sample of 5 percent

of all PSUs and established plots at all three

SSU points within this 5-percent sample. In

addition, any SSU having 20 percent or greater

tree cover was also included in the NCFIA

sample. This subsampling of the NRI (5

percent of the less than 20 percent tree cover

and 100 percent of the 20 percent or more tree

cover) formed the basis of the estimation of

means within strata. The average sampling

intensity was approximately one ground plot

per 6,000 acres in the forest stratum and one

ground plot per 60,000 acres in the nonforest

stratum.

COMBINED ESTIMATE

BASED ON THE TWO

INDEPENDENT

INVENTORIES

These two inventories produced two independent estimates of the forest resources. Final

estimates presented in this report are based on

weighted averages from these two independent

estimates. Weighting was proportional to the

number of ground plots on forest land for the

estimates of most items including area,

number of trees, volume, growth, mortality,

and biomass. Weighting based on the number

of remeasurement plots on forest land was

used for estimates of items that can only be

obtained from remeasurement plots, including removals and area change over time.

FIELD MEASUREMENTS:

1980 INVENTORY PLOT

DESIGN

On plots classified as timberland, wooded

pasture, or windbreak (at least 120 feet wide),

a ground plot was established or remeasured,

or the growth and mortality of its trees were

predicted using the STEMS models. Old plots

selected for remeasurement that could not be relocated were replaced with new plots at the

approximate locations of the old plots. Each

ground plot consisted of a cluster of 10

subplots collectively covering approximately 1

acre. Trees 5.0 inches or greater in d.b.h. were

sampled using 37.5 basal area factor (BAF)

variable-radius plots, and trees less than 5.0

inches d.b.h. were sampled on 6.8-foot radius

(1/300th acre) microplots established at the

centers of subplots 1, 2, and 3. Under the

estimation procedures used for this inventory,

an entire plot was represented by a single

condition class where condition was determined by forest type, stand-size class, land use,

stand origin, and density. Thus, the arrangement of the 10 subplots within the plot was

adjusted if any subplots were located in

condition classes different from that of subplot

1. In particular, if a subplot was located outside

the condition class for the plot, it was reestablished or rotated into the condition class

used for the entire plot. For example, if 17

North Dakota South Dakota Both States,

state-wide inventory outside BIA lands

inventory BHNF only

Forest (20 percent

 tree cover or greater) 2,721 841 584

Nonforest (less than 20

 percent tree cover) 234,858 192,495 70,030 Total 237,579 193,336 70,614
subplots 1 through 9 were located in forest

land and subplot 10 was located in a pasture,

then subplot 10 was rotated back into the forest

land condition class.

FIELD MEASUREMENTS:

1994-1996 INVENTORY

PLOT DESIGN

Field ground plots were established or remeasured, or the growth and mortality of

their trees were predicted using the STEMS

models for all forest lands (including reserved

forest land, unproductive forest land, and

timberland), wooded pasture, or windbreaks

(at least 120 feet wide). Establishing ground

plots on all forest lands represented a major

change between the 1980 and the 1994-1996

inventories.

The new overall plot layout consisted of 10

subplots arranged in a cluster with 70 feet

between subplots. The basic locations of plots

and subplots were the same as in the 1980 plot

layout. All trees less than 5 inches in d.b.h.

were measured on 6.8-foot radius (1/300th

acre) microplots established at the centers of all

10 subplots. (In 1980, these microplots were

measured only on subplots 1, 2, and 3). This

radius was the maximum distance at which a

5.0-inch-d.b.h. tree would be selected using a

basal area factor (BAF) of 37.5. Trees with

diameters between 5.0 and 17.0 inches were

selected for measurement at each of the 10

subplots with a BAF of 37.5. All trees greater

than 17.0 inches d.b.h. located within a 24-foot

radius macroplot centered at each of the 10

subplots were selected for measurement.

In the new plot design, subplots of the same

plot were not rotated, even if they were located

in multiple condition classes or straddled

condition classes. As in 1980, factors determining condition class were forest type, stand-size

class, land use, stand origin, and density. Plots

with multiple condition classes were mapped in

the field to record how the boundaries between

classes split the plot. This procedure identified

the area of the plot located in each class and

assigned each tree to a specific class. When

multiple condition classes occurred on a plot,

all information normally collected for the plot

as a whole, such as forest type, site index, stand

age, and stand-size class, was collected for each

condition class.

On remeasured plots, the rotated subplots and

all trees measured from the 1980 plot design

were also remeasured to obtain change data

such as growth and mortality. On new plots,

subplots were not rotated.

NEW INVENTORY PLOTS

New ground plots were selected from the plots

identified in NCFIA’s evaluation of the NRCSNRI inventory. These new ground plots were

established, and measures of current classification such as land use, forest type, and ownership, as well as size and condition of all trees

on the plot, were recorded. These locations

were monumented for future remeasurement.

OLD INVENTORY PLOTS

Old inventory plots are those plots established,

monumented, and measured as part of the

1980 field inventory. The Inventory procedures

used for these old plots were different from

those used for new plots. Old plots were

classified as “disturbed” on the basis of aerial

photo analyses if either:1) a reduction in

vegetation on the plot occurred between

inventories that resulted in a detectable change

in the structure or function of the plant

community; or 2) conditions on the plot were

such that the STEMS models were unable to

accurately predict growth or mortality. Plots not

predicted to be disturbed were classified as

“undisturbed.” All disturbed plots and a onethird sample of the undisturbed plots were field remeasured to obtain estimates of current

conditions and changes since the last inventory.

All remaining live trees measured on these plots

in 1980 were remeasured, and all new trees

were identified and measured.

18
Of the timberland plots measured in 1980,

many were not remeasured for the 1996

inventory. On BIA lands, a total of 6 timberland plots were classified “undisturbed” and

not remeasured (table E). Growth and

mortality for these plots were predicted using

the STEMS models as a means of obtaining

growth and current volume. A comparison of

the predicted growth and mortality for these

undisturbed plots and observations of growth

and mortality for the one-third sample of

remeasured undisturbed plots was used to

adjust the model predictions to accommodate

local conditions. The adjustment procedure is

a modified version of the method described by

Smith (1983).

Table E.—Distribution of ground plots by ground land-use class and type of plot, 1994-1996 inventory of the North Dakota

and South Dakota forest resources

19

The undisturbed timberland plots whose

growth and mortality were predicted were

treated in the estimation process as measured

ground plots, even though they were not

visited by field crews. The plot records for

these plots were sent to the field for verification

of current ownership information. All old plots

classified as disturbed were selected for

remeasurement to assess and verify changes

since the last inventory. Table E summarizes

the distribution of all ground plots by type and

plot.

1 Plots that straddle more than one land use are included in this table in the land-use class that occurs first on this list. For example, a plot that straddled

other forest land and water would be includd in this table as other forest land.

Sample base 1

1980 NCFIA Remeasurement NRCS-NRI

Remeasured Updated New Total plots

North Dakota statewide inventory

Timberland 125 48 85 258

Other forest land 44 0 12 56

Nonforest with trees 333 13 80 426

Nonforest without trees 8,994 10 734 9,738

Water 121 0 10 131

 Total 9,617 71 921 10,609

South Dakota inventory outside

 the Black Hills National Forest

Timberland 322 10 76 408

Other forest land 33 0 6 39

Nonforest with trees 437 1 94 632

Nonforest without trees 5,995 0 739 6,734

Water 101 0 4 105

 Total 6,888 11 919 7,918

Both States, BIA lands only

Timberland 63 6 62 131

Other forest land 11 0 6 17

Nonforest with trees 109 0 66 175

Nonforest without trees 2,117 0 560 2,677

Water 31 0 5 36

 Total 2,331 6 699 3,036
COMPUTATION OF

ESTIMATES

Area

All area estimates were made using two-phase

estimation methods. In this type of estimation,

a preliminary estimate of area by land use is

obtained from stratification (Phase 1) and

corrected by plot measurements (Phase 2). A

complete description of these methods is

presented by Loetsch and Haller (1964).

Volume

Estimates of volume per acre were made from

the measurements and predictions for trees on

each of the 10 subplots per plot. For each

condition class on a plot, the volume per acre

estimate was multiplied by the area estimate

represented by the condition, and these

products were summed over all plots to obtain

estimates of total volume for the condition

class. Net cubic and board foot volumes are

based on tree measurements (d.b.h., tree class,

and site index) and volume equations presented by Hahn and Hansen (1984).

Growth and Mortality

On remeasured plots, estimates of growth and

mortality per acre were derived from

remeasurements and observations of trees that

died between inventories. These estimates were

based on the remeasurement of the 1980

inventory plots using the 1980 plot design.

Growth, reported as average annual net growth

between the 1980 and 1994 inventories, was

computed from data for both plots that had

been remeasured and plots whose growth and

mortality had been predicted using methods

presented by Van Deusen et al. (1986). Average

annual mortality was also calculated for the

remeasurement period.

On new plots, estimates of growth and

mortality were obtained by using the STEMS

models to predict growth and mortality for 1

year. Current diameter and living tree estimates

for old undisturbed plots were predicted using

growth and mortality predictions and were

derived in the same manner as for remeasured

plots. To accommodate local conditions,

predictions of growth and mortality from the

STEMS models were adjusted using data from

the undisturbed remeasured plots. As with

volume, total growth and mortality estimates

were obtained by multiplying the plot-level per

acre estimates by area expansion factors and

then summing over plots. Current annual net

growth for 1994 was computed using adjusted,

1-year STEMS predictions of growth for all

inventory plots.

Average Annual Removals

Average annual growing-stock and sawtimber

removals (1980-1993) were estimated only

from the remeasured plots. These estimates

were based on the remeasurement of the 1980

inventory plots using the 1980 plot design.

Measurements for new plots and predictions

from the STEMS models were not used to

estimate removals. These estimates were

obtained from trees measured in the last

inventory and either cut or otherwise removed

from the timberland base. Because

remeasurement plots constitute about one-half

the total ground plots, and not all remeasured

plots had cutting, average annual removals

estimates have greater sampling errors than

volume and growth estimates.

20
Log grades and tree grades were based on the

classification of external characteristics as

indicators of quality. Log grades or tree grades

were taken on approximately one-third of the

sample plots. All sawtimber softwood sample

trees were graded for quality and assigned a

butt log grade. All sawtimber hardwood sample

trees were graded for quality and assigned a

tree grade. The volume yield by log grade or

tree grade for this sample was used to distribute the volume of the ungraded sample trees

by species group.

Hardwood sawtimber trees were graded

according to “Hardwood tree grades for factory

lumber” (Hanks 1976). The best 12-foot

section of the lowest 16-foot hardwood log was

used for grading. Hardwood sawtimber trees

that did not meet minimum tree grade

specifications for grades 1 through 3 were

assigned grade 4 according to Forest Service

standard specifications for hardwood construction logs described in “A guide to hardwood

log grading” (Rast et al. 1973).

Ponderosa pine and other softwood sawtimber

trees were graded according to USDA Forest

Service specifications. For all softwoods, the

first merchantable 16-foot log or shorter

lengths down to 12 feet were used for grading.

21

D.b.h. Scribner rule conversion factor

(inches) Softwoods Hardwoods

9.0-10.9 0.7830 —

11.0-12.9 0.8287 0.8317

13.0-14.9 0.8577 0.8611

15.0-16.9 0.8784 0.8827

17.0-18.9 0.8945 0.8999

19.0-20.9 0.9079 0.9132

21.0-22.9 0.9168 0.9239

23.0-24.9 0.9240 0.9325

25.0-26.9 0.9299 0.9396

27.0-28.9 0.9321 0.9454

 29.0+ 0.9357 0.9544

TREE AND LOG GRADES

The Forest Service reports all board foot

volume in International 1/4-inch rule. In the

Dakotas, the Scribner log rule is commonly

used. Scribner log rule conversion factors were

derived from full tree measurements and an

equation developed by Wiant and Castenaeda

(1977). The factors (multipliers) used to

convert board foot International volumes to

the Scribner rule are shown in the following

tabulation:
a Hanks (1976)

b Whenever a 14- or 16-foot section of the butt 16-foot log is better than the best 12-foot section,

the grade of the longer section will become the grade of the tree. This longer section, when used,

is the basis for determining the grading factors such as diameter and cull deduction.

c In basswood and ash, d.i.b. at top of grading section must be 12 inches and d.b.h. must be 15

inches.

d Grade 2 trees can be 10 inches d.i.b. at top of grading section if they otherwise meet surface

requirements for small grade 1's.

e A clear cutting is a portion of a face free of defects, extending the width of the face. A face is onefourth of the surface of the grading section as divided lengthwise.

f Fifteen percent crook and sweep or 40 percent total cull deduction are permitted in grade 2 trees,

if size and surface of grading section qualify as grade 1. If rot shortens the required clear cuttings

to the extent of dropping the butt log to grade 2, do not drop the tree's grade to 3 unless the cull

deduction for rot is greater than 40 percent.

Hardwood Tree Grade for Factory Lumber a

Grade factor Tree grade 1 Tree grade 2 Tree grade 3

Length of grading zone (feet) Butt 16 Butt 16 Butt 16

Length of grading section b (feet) Best 12 Best 12 Best 12

D.b.h., minimum (inches) 16 c 13 11

D.i.b., minimum at top of grading

 section (inches) 13 c

 16 20 11 d 12 8

Clear cuttings (on the 3 best faces) e

 Length, minimum (feet) 7 5 3 3 3 2

 Number on face (maximum) 2 2 3 Unlimited

 Yield in face length (minimum) 5/6 4/6 3/6

Cull deduction (including crook and

 sweep, but excluding shake)

 maximum within grading

 section (percent) 9 f 50

22
Forest Service Standard Specifications for Hardwood Construction Logs

(tie and timber logs) a, b

Position in tree Butts and uppers

Minimum diameter, small end 8 inches

Minimum length without trim 8 feet

Clear cuttings No requirements

Sweep allowance One-fourth of the diameter at the small

end for each 8 feet of length.

Sound surface defects:

Single knots Any number, if no one knot has an average

diameter above the callus in excess of one-third

of the log diameter at point of occurrence.

Whorled knots Any number, if the sum of knot diameters above

the callus does not exceed one-third of the log

diameter at point of occurrence.

Holes Any number, provided none has a diameter

over one-third of the log diameter at point of

occurrence and none extends more than 3

inches into included timber c

.

Unsound surface defects: Same requirements as for sound defects if

they extend into included timber.

No limit if they do not.

a Rast et al. (1973). b These specifications are minimum for the class. If, from a group of logs, factory logs are selected first,

thus leaving only nonfactory logs from which to select construction logs, then the quality range of the

construction logs so selected is limited, and the class may be considered a grade. If selection for

construction logs is given first priority, it may be necessary to subdivide the class into grades.

c Included timber is always square, and dimension is judged from small end.

23
Log Grades for Ponderosa Pine and Other Softwoods

Grade 1

1. Trees must be 16 inches in diameter or larger, grading section 12 feet in length or longer,

and with deduction for defect not over 30 percent of gross scale.

2. Trees must be at least 75 percent clear on each of three faces.

3. All knots outside clear cutting must be sound and not more than 2-1/2 inches in size.

Grade 2

1. Trees must be 12 inches in diameter or larger, grading section 12 feet in length or longer,

and with a net scale after deduction for defect of at least 50 percent of the gross scale

deducted for defect.

2. Trees must be at least 50 percent clear on each of three faces or 75 percent clear on two

faces.

Grade 3

1. Trees must be 6 inches in diameter or larger, grading section 12 feet in length or longer, and

with a net scale after deduction for defect of at least 50 percent of the gross contents of

the log.

Note: Diameters are diameter inside bark (d.i.b.) at small end of grading section.

Percent clear refers to percent clear in one continuous section.

METRIC EQUIVALENTS

1 acre = 4,046.86 square meters or 0.405

hectare.

1,000 acres = 405 hectares.

1 cubic foot = 0.0283 cubic meter.

1 foot = 30.48 centimeters or 0.3048 meter.

1 inch = 25.4 millimeters, 2.54 centimeters, or

0.0254 meter.

1 pound = 0.454 kilograms.

1 ton = 0.907 metric tons.

24
TREE SPECIES GROUPS IN NORTH AND SOUTH DAKOTA

(LITTLE 1981)

Hardwoods

Silver maple 2 ......................................................................................................Acer saccharinum

Paper birch 2 ....................................................................................................... Betula papyrifera

River birch 2 .......................................................................................................................B. nigra

Hackberry 2 ........................................................................................................ Celtis occidentalis

Ashes

 Black ash 2 ........................................................................................................... Fraxinus nigra

 Green ash 1 ........................................................................................................ F. pennsylvanica

Cottonwoods 2

 Eastern cottonwood ..........................................................................................Populus deltoides

 Plains cottonwood ......................................................................................................P. sargentii

Balsam poplar 2 ......................................................................................................... P. balsamifera

Quaking aspen 2 ........................................................................................................ P. tremuloides

Black cherry 2 ......................................................................................................... Prunus serotina

Select white oaks 1

 Bur oak ........................................................................................................Quercus macrocarpa

Black willow 2 ............................................................................................................... Salix nigra

American basswood 2 .............................................................................................Tilia americana

Elms

 American elm 2 ................................................................................................ Ulmus americana

 Siberian elm 2 ...............................................................................................................U. pumila

 Slippery elm 2 ................................................................................................................ U. rubra

Other hardwoods

 Boxelder 2 .............................................................................................................. Acer negundo

 White poplar 2 ........................................................................................................ Populus alba

Softwoods 2

Rocky Mountain juniper ............................................................................... Juniperus scopulorum

Eastern redcedar ......................................................................................................... J. virginiana

Ponderosa pine ..................................................................................................... Pinus ponderosa

White spruce .............................................................................................................. Picea glauca

Other softwoods

 Blue spruce ................................................................................................................. P. pungens

Noncommercial species

Eastern hophornbeam ......................................................................................... Ostrya virginiana

Hawthorn ............................................................................................................... Crataegus spp.

Wild plum ...................................................................................................................Prunus spp.

Chokecherry ............................................................................................................... P. virginiana

Pin cherry ................................................................................................................ P. pensylvanica

Canada plum ......................................................................................................................P. nigra

Diamond willow ....................................................................................................... Salix bebbiana

White willow ....................................................................................................................... S. alba

Peachleaf willow ..................................................................................................... S. amygdaloides

1 This species or species group is considered a hard hardwood, with an average specific gravity greater than or

equal to 0.50.

2 This species or species group is considered a softwood or a soft hardwood, with an average specific gravity of

less than 0.50.

Note: Many additional tree

species have been planted

around homesteads and

farm headquarters in rural

North and South Dakota, in

urban settings, and in tree

plantings. However, only

those species encountered

during the third inventory

of the forest resources of

North and South Dakota

are listed here. For a

complete list of all of the

tree species, please

contact the North or South

Dakota Forest Service or

your local Extension

Service office.

25
DEFINITION OF TERMS

Average annual mortality of

growing stock

The average cubic foot volume of sound

wood in growing-stock trees that died in

one year. Average annual mortality is the

average for the years between inventories

(1980 through 1993 in this report).

Average annual mortality of

sawtimber

The average board foot volume of sound

wood in sawtimber trees that died in one

year. Average annual mortality is the

average for the years between inventories

(1980 through 1993 in this report).

Average annual removals from

growing stock

The average net growing-stock volume in

growing-stock trees removed annually for

roundwood forest products, in addition to

the volume of logging residues and the

volume of other removals. Average annual

removals of growing stock is the average

for the years between inventories (1980

through 1993 in this report) and is based

on information obtained from remeasurement plots (see Survey Procedures in the

appendix).

Average annual removals from

sawtimber

The average net board foot sawtimber

volume of live sawtimber trees removed

annually for roundwood forest products,

in addition to the volume of logging

residues, and the volume of other

removals. Average annual removals of

sawtimber is the average for the years

between inventories (1980 through 1993

in this report) and is based on information

obtained from remeasurement plots (see

Survey Procedures in the appendix).

Average annual net growth of

growing stock

The annual change in cubic foot volume

of sound wood in live sawtimber and

poletimber trees, and the total volume of

trees entering these classes through

ingrowth, less volume losses resulting

from natural causes. Average net annual

growing stock is the average for the years

between inventories (1980 through 1993

in this report).

Average annual net growth of

sawtimber

The annual change in the board foot

volume of live sawtimber trees, and the

total volume of trees reaching sawtimber

size, less volume losses resulting from

natural causes. Average net annual growth

of sawtimber is the average for the years

between inventories (1980 through 1993

in this report).

Basal area

Tree area in square feet of the cross section

at breast height (4.5 ft) of a single tree.

When the basal areas of all trees in a stand

are summed, the result is usually expressed as square feet of basal area per

acre.

Biomass

The aboveground volume of all live trees

(including bark but excluding foliage)

reported in green tons (i.e., green weight).

Biomass has four components:

Bole.—Biomass of a tree from 1 foot

above the ground to a 4-inch top

outside bark.

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 in

diameter at breast height.

Stump.—Biomass of a tree 5 inches

d.b.h. and larger from the ground to a

height of 1 foot.

Bolts

Roundwood logs of less than 8 feet in

length that are converted into shingles,

cooperage stock, dimension stock, blocks,

blanks, excelsior, etc. No minimum

diameter limits. Does not include logs

used for the manufacture of pulp or

veneer.

Commercial species

Tree species presently or prospectively

suitable for industrial wood products.

(Note: Excludes species of typically small

size, poor form, or inferior quality.)

Cord

One standard cord is 128 cubic feet of

stacked wood, including bark and air

space. Cubic feet can be converted to

solid wood standard cords by dividing by

79.

Corporate

Lands owned by a private corporation not

in the business of operating primary

wood-using plants.

County and municipal land

Land owned by counties and local public

agencies or municipalities, or land leased

to these governmental units for 50 years

or more.

26
Cropland

Land under cultivation within the last 24

months, including cropland harvested,

crop failures, cultivated summer fallow,

idle cropland used only for pasture,

orchards, active Christmas tree plantations

indicated by annual shearing, nurseries,

and land in soil improvement crops, but

excluding land cultivated in developing

improved pasture.

Cull

Portions of a tree that are unusable for

industrial wood products because of rot,

missing or dead material, form, or other

defect.

Current annual net growth of

growing stock

The annual change in volume of sound

wood in live sawtimber and poletimber

trees, and the total volume of trees

entering these classes through ingrowth,

less volume losses resulting from natural

causes, reported for a single year (1993 in

this report). Current growth is based on

an estimate of the current annual increment of each growing-stock tree in the

inventory.

Current annual net growth of

sawtimber

The annual change in the volume of live

sawtimber trees, and the total volume of

trees reaching sawtimber size, less volume

losses resulting from natural causes,

reported for a single year (1993 in this

report). Current growth is based on an

estimate of the current annual increment

of each growing-stock tree in the inventory.

Current annual removals from

growing stock

The current net growing-stock volume in

growing-stock trees removed annually for

roundwood forest products, in addition to

the volume of logging residues, and the

volume of other removals. Current annual

removals of growing stock is reported for

a single year (1993 in this report); it is

based on a survey of primary wood

processing mills to determine removals for

products and on information from

remeasurement plots (see Survey Procedures in the appendix) to determine

removals due to land-use change.

Current annual removals from

sawtimber

The current net board foot sawtimber

volume of live sawtimber trees removed

annually for roundwood forest products,

in addition to the volume of logging

residues, and the volume of other

removals. Current annual removals of

sawtimber is reported for a single year

(1993 in this report); it is based on a

survey of primary wood processing mills

to determine removals for products and

on information from remeasurement plots

(see Survey Procedures in the appendix)

to determine removals due to land-use

change.

Diameter class

A classification of trees based on diameter

outside bark, measured at breast height

4.5 feet above the ground. (Note: d.b.h. is

the common abbreviation for diameter at

breast height.) Two-inch diameter classes

are commonly used in Forest Inventory

and Analysis, with the even inch the

approximate midpoint for a class. For

example, the 6-inch class includes trees

5.0 through 6.9 inches d.b.h.

Diameter at breast height (d.b.h.)

The outside bark diameter at 4.5 feet

(1.37 m) above the forest floor on the

uphill side of the tree. For determining

breast height, the forest floor includes the

duff layer that may be present, but does

not include unincorporated woody debris

that may rise above the ground line.

Forest industry land

Land owned by companies or individuals

operating primary wood-using plants.

Forest land

Land at least 10 percent stocked (Note:

historically, 16.7 percent was used based

on full stocking equaling 167 percent.

Consequentially, this equaled a standard

of 10 percent based on the 100-percent

scale that is now used) by forest trees of

any size, or formerly having had such tree

cover, and not currently developed for

nonforest use. (Note: Stocking is measured by comparing specified standards

with basal area and/or number of trees,

age or size, and spacing.) The minimum

area for classification of forest land is 1

acre. Roadside, streamside, and

shelterbelt strips of timber must have a

crown width of at least 120 feet to qualify

as forest land. Unimproved roads and

trails, streams, or other bodies of water or

clearings in forest areas shall be classed as

forest if less than 120 feet wide. (See Tree,

Land, Timberland, Reserved forest land,

Other forest land, Stocking, and Water.)

Forest type

A classification of forest land based on the

species forming a plurality of live tree

stocking. The associated species for each

forest type are based on net volume of

growing stock and all live biomass by

species group and forest type from the

27
1994-1996 inventory of North and South

Dakota forests. Major forest types found

are:

Ponderosa pine.—Forests in which

ponderosa pine comprises a majority of

the forest stocking.

Rocky Mountain juniper.—Forests in

which Rocky Mountain juniper comprises

a majority of forest stocking. A common

associate of the Rocky Mountain juniper

forest type is green ash.

Bur oak.—Forests in which bur oak

comprises a majority of forest stocking.

Species commonly associated with the bur

oak forest type in North and South Dakota

include basswood and green ash.

Cottonwood.—Forests in which cottonwood comprises a majority of the forest

stocking. A common associate of the

cottonwood forest type in North and

South Dakota is green ash.

Elm-ash-cottonwood.—

Lowland forests in which cottonwood,

green ash, and elm comprise a plurality of

the forest stocking. A common associate of

the elm-ash-cottonwood forest type in

North and South Dakota is bur oak.

Basswood.—Forests in which hardwoods

comprise a plurality of the forest stocking.

Species commonly associated with the

basswood forest type in North and South

Dakota include bur oak and green ash.

Aspen-birch.—Forests in which quaking

aspen, paper birch, and river birch, singly

or in combination, comprise a plurality of

forest stocking. Species commonly

associated with the aspen-birch forest type

in North and South Dakota include

balsam poplar, bur oak, and green ash.

Elm-ash.—Upland forests in which elm

and green ash comprise a plurality of the

forest stocking. Species commonly

associated with the elm-ash forest type in

North and South Dakota include cottonwood and bur oak.

Growing-stock tree

A live tree of commercial species that

meets specified standards of size, quality,

and merchantability. (Note: Excludes

rough, rotten, and dead trees.)

Growing-stock volume

Net volume in cubic feet of growing-stock

trees 5.0 inches d.b.h. and over, from 1

foot above the ground to a minimum 4.0-

inch top diameter outside bark of the

central stem or to the point where the

central stem breaks into limbs.

Hard hardwoods

Hardwood species with an average

specific gravity greater than 0.50 such as

oaks, hard maple, hickories, and ash.

Hardwoods

Dicotyledonous trees, usually broadleaved and deciduous. (See Soft hardwoods and Hard hardwoods.)

Improved pasture

Land currently improved for grazing by

cultivating, seeding, irrigating, or clearing

trees or brush and less than 10 percent

stocked with trees.

Indian land

Land held in trust by the United States for

tribes or individual Indians.

Industrial wood

All roundwood products except residential fuelwood.

Land

(a) Bureau of the Census.—Dry land

and land temporarily or partly covered by

water such as marshes, swamps, and river

flood plains, streams, sloughs, estuaries,

and canals less than one-eighth of a

statute mile wide; and lakes, reservoirs,

and ponds less than 40 acres in area.

(b) Forest Inventory and Analysis.—

The same as the Bureau of the Census,

except minimum width of streams, etc., is

120 feet and minimum size of lakes, etc.,

is 1 acre.

Live trees

Growing-stock, rough, and rotten trees

1.0 inch d.b.h. and larger.

Log grade

A log classification based on external

characteristics as indicators of quality or

value. Log grade was assigned to a sample

of softwood sawtimber trees throughout

the States during the 1994 inventory.

Also see Tree grade. (See appendix for

specific grading factors used.)

Logging residue

The unused portions of the merchantable

central stem of growing-stock trees cut or

killed by logging.

Marsh

Nonforest land that characteristically

supports low, generally herbaceous or

shrubby vegetation, and that is intermittently covered with water.

28
Merchantable

Refers to a pulpwood or saw log section

that meets pulpwood or saw log specifications, respectively.

Miscellaneous Federal land

Federal land other than national forest

and land administered by the Bureau of

Land Management, Corps of Engineers, or

Bureau of Indian Affairs.

National forest land

Federal land that has been legally

designated as national forest or purchase

units, and other land administered by the

USDA Forest Service. For example, the

administrative unit in North Dakota is

named “Dakota Prairie Grasslands,” and

the administrative unit in South Dakota is

the Black Hills National Forest.

Net volume

Gross volume less deductions for rot,

sweep, or other defect affecting use for

timber products.

Noncommercial species

Tree species of typically small size, poor

form, or inferior quality that normally do

not develop into trees suitable for

industrial wood products.

Nonforest land

Land that has never supported forests,

and land formerly forested where use for

timber management is precluded by

development for other uses. (Note:

Includes areas used for crops, active

Christmas tree plantations as indicated by

annual shearing, orchards, nurseries,

improved pasture, residential areas, city

parks, improved roads of any width and

adjoining clearings, powerline clearings of

any width, and 1- to 40-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 more than 1 acre in area to qualify as

nonforest land.

Nonforest land without trees.—

Nonforest land with no live trees

present.

Nonforest land with trees.—Nonforest

land with one or more trees per acre at

least 5 inches d.b.h.

Nonstocked land

Timberland less than 10 percent stocked

with all live trees.

Other forest land

Forest land not capable of producing 20

cubic feet per acre per year of industrial

wood crops under natural conditions and

not associated with urban or rural

development. Many of these sites contain

tree species that are not currently used for

industrial wood production or trees of

poor form, small size, or inferior quality

that are unfit for most industrial products.

Unproductivity may be the result of

adverse site conditions such as sterile soil,

dry climate, poor drainage, high elevation,

and rockiness. This land is not withdrawn

from timber use.

Other removals

Growing-stock trees removed but not used

for products, or trees left standing but

“removed” from the timberland classification by land-use change. Examples are

removals from cultural operations such as

timber stand improvement work and land

clearing, and the standing volume on land

classified originally as timberland but later

designated as reserved from timber

harvesting (such as a newly established

State park).

Pasture

Land presently used for grazing or under

cultivation to develop grazing.

Plant byproducts

Plant residues used for products such as

mulch, pulp chips, and fuelwood.

Plantation

An artificially reforested area sufficiently

productive to qualify as timberland. The

planted species is not necessarily predominant. Christmas tree plantations,

which are considered cropland, are not

included.

Plant residues

Wood and bark materials generated at

manufacturing plants during production

of other products.

Poletimber stand

(See Stand-size class.)

Poletimber tree

A live tree of commercial species at least

5.0 inches d.b.h., but smaller than

sawtimber size.

Potential productivity class

A classification of forest land in terms of

inherent capacity to grow crops of

industrial wood. The class identifies the

potential growth in merchantable cubic

feet/acre/year at culmination of mean

annual increment of fully stocked natural

stands.

Private individual land

Privately owned land not owned by forest

industry. This class includes the formerly

used Farmer and Miscellaneous private

classes.

29
Reserved forest land

Forest land withdrawn from timber use

through statute, administrative regulation,

or designation. Note: historically, Christmas tree plantations were classified as

reserved forest land. However, Christmas

tree plantations are now classified as

cropland.

Rotten tree

Live trees of commercial species that do

not contain at least one 12-foot saw log or

two saw logs 8 feet or longer, now or

prospectively, and/or do not meet regional

specifications for freedom from defect

primarily because of rot; that is, when

more than 50 percent of the cull volume

in a tree is rotten.

Rough tree

(a) Live trees of commercial species

that do not contain at least one merchantable 12-foot saw log or two saw logs 8 feet

or longer, now or prospectively, and/or do

not meet regional specifications for

freedom from defect primarily because of

roughness or poor form, and

(b) all live trees of noncommercial

species.

Roundwood products

Logs, bolts, or other round sections

(including chips from roundwood) cut

from trees for industrial or consumer uses.

(Note: Includes saw logs, veneer logs, and

bolts; cooperage logs and bolts; pulpwood; fuelwood; pilings; poles; posts;

hewn ties; mine timbers; and various

other round, split, or hewn products.)

Salvable dead tree

A standing or down dead tree considered

merchantable by regional standards.

Sapling

A live tree 1.0 to 5.0 inches d.b.h.

Sapling-seedling stand

(See Stand-size class.)

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 outside bark

(d.o.b.) for softwoods of 7.0 inches (9.0

inches for hardwoods) or other combinations of size and defect specified by

regional standards.

Saw log portion

That part of the bole of sawtimber trees

between the stump and the saw log top.

Saw log top

The point on the bole of sawtimber trees

above which a saw log cannot be produced. The minimum saw log top is 7.0

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

d.o.b. for hardwoods.

Sawtimber stand

(See Stand-size class.)

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.

Seedling

A live tree less than 1.0 inch d.b.h. that is

expected to survive. Only softwood

seedlings more than 6 inches tall and

hardwood seedlings more than 1 foot tall

are counted.

Short-log (rough tree)

A sawtimber-size tree of commercial

species that contains at least one

merchantable 8- to 11-foot saw log but

not a 12-foot saw log.

Shrub

A woody, perennial plant differing from a

perennial herb in its persistent and

woody stem(s) and less definitely from a

tree in its lower stature and/or the

general absence of a well-defined main

stem. For this report, shrubs were

separated somewhat arbitrarily into tall

and low shrubs as follows:

Tall shrubs.—Normally taller than 1.6

to 3.2 feet

Low shrubs.—Normally shorter than

1.6 to 3.2 feet. (Woody perennial

vines, such as grape, were included

with low shrubs.)

Shrub and tree seedling biomass

The total aboveground weight of trees

less than 1.0 inch in diameter and all

shrubs.

Site index

An expression of forest site quality based

on the height of a free-growing dominant

or codominant tree of a representative

species in the forest type at age 50.

30
Soft hardwoods

Hardwood species with an average

specific gravity less than 0.50, such as

cottonwood, red maple, basswood, and

willow.

Softwoods

Coniferous trees, 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 class

A classification based on age of the main

stand. Main stand refers to trees of the

dominant forest type and stand-size class.

Stand-size class

A classification of stocked (see Stocking)

forest land based on the size class of live

trees on the area; that is, sawtimber,

poletimber, or seedlings and saplings.

Sawtimber stands.—Stands with half or

more of live tree stocking in sawtimber or poletimber trees, and with

sawtimber stocking at least equal to

poletimber stocking.

Poletimber stands.—Stands with half or

more of live tree stocking in

poletimber and/or sawtimber trees,

and with poletimber stocking

exceeding that of sawtimber.

Sapling-seedling stands.—Stands with

more than half of the live tree

stocking in saplings and/or seedlings.

State land

Land owned by the State of North or

South Dakota or leased to it for 50 years

or more.

Stocking

The degree of occupancy of land by all live

trees, measured by basal area and/or the

number of trees in a stand by size or age

and spacing, compared to the basal area

and/or number of trees required to fully

use the growth potential of the land; that

is, the stocking standard. A stocking

percent of 100 indicates full use of the site

and is equivalent to 80 square feet of basal

area per acre in trees 5.0 inches d.b.h. and

larger. In a stand of trees less than 5 inches

d.b.h., a stocking percent of 100 would

indicate that the present number of trees is

sufficient to produce 80 square feet of

basal area per acre when the trees reach 5

inches d.b.h.

Stands are grouped into the following

stocking classes:

Overstocked stands.—Stands in which

stocking of live trees is 100 percent or

more.

 Fully stocked stands.—Stands in which

stocking of live trees is from 60 to 100

percent.

Medium stocked stands.—Stands in

which stocking of live trees is from 35

to 60 percent.

Poorly stocked stands.—Stands in which

stocking of live trees is from 10 to 35

percent.

Nonstocked areas.—Timberland on

which stocking of live trees is less

than 10 percent.

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.

Timberland

Forest land that is producing, or is

capable of producing, more than 20 cubic

feet per acre per year of industrial wood

crops under natural conditions, that is not

withdrawn from timber use, and that is

not associated with urban or rural

development. Currently inaccessible and

inoperable areas are included. (Timberland was formerly called commercial

forest land.)

Tree

A woody plant usually having one or

more erect perennial stems, a stem

diameter at breast height of at least 3

inches, a more or less definitely formed

crown of foliage, and a height of at least

13 feet at maturity.

Tree biomass

The total aboveground weight (including

the bark but excluding the foliage) of all

trees from 1 to 5 inches in d.b.h., and the

total aboveground weight (including the

bark but excluding the foliage) from a 1-

foot stump for trees more than 5 inches in

diameter.

Tree grade

A classification of the lower 16 feet of the

bole of standing trees based on external

characteristics as indicators of the quality

and quantity of lumber that could be

produced from the tree. Tree grade was

assigned to a sample of hardwood

31
sawtimber trees during the 1994 inventory. Also see Log grade. (See appendix for

specific grading factors used.)

Tree size class

A classification of trees based on diameter

at breast height, including sawtimber

trees, poletimber trees, saplings, and

seedlings.

Upper stem portion

That part of the bole of sawtimber trees

above the saw log top to a minimum top

diameter of 4.0 inches d.o.b. or to the

point where the central stem breaks into

limbs.

Urban and other areas

Areas within the legal boundaries of cities

and towns; suburban areas developed for

residential, industrial, or recreational

purposes; school yards; cemeteries; roads;

railroads; airports; beaches; powerlines

and other rights-of-way; or other nonforest

land not included in any other specified

land-use class.

Urban forest land

Land that would otherwise meet the

criteria for timberland, but that is in an

urban-suburban area surrounded by

commercial, industrial, or residential

development and not likely to be managed

for the production of industrial wood

products on a continuing basis. Wood

removed would be for land clearing,

fuelwood, or esthetic purposes. Such forest

land may be associated with industrial,

commercial, residential subdivision,

industrial parks, golf course perimeters,

airport buffer strips, and public urban

parks that qualify as forest land.

Water

(a) Bureau of the Census.—Permanent inland water surfaces, such as lakes,

reservoirs, and ponds at least 40 acres in

area; and streams, sloughs, estuaries, and

canals at least one-eighth of a statute

mile wide.

(b) Noncensus.—Permanent inland

water surfaces, such as lakes, reservoirs,

and ponds from 1 to 39.9 acres in area;

and streams, sloughs, estuaries, and

canals from 120 feet to one-eighth of a

statute mile wide.

Wooded pasture

Improved pasture with more than 10

percent stocking in live trees, but less

than 25 percent stocking in growingstock trees. Area is currently improved

for grazing or there is other evidence of

grazing.

Wooded strip

An acre or more of natural continuous

forest land that would otherwise meet

survey standards for timberland except

that it is less than 120 feet wide.

32
LITERATURE CITED

Belcher, D.W.; Holdaway, M.R.; Brand,

G.J. 1982. A description of STEMS the

stand and tree evaluation and modeling

system. Gen. Tech. Rep. NC-79. St.

Paul, MN: U.S. Department of Agriculture, Forest Service, North Central

Forest Experiment Station. 18 p.

Cochran, W.G. 1977. Sampling techniques. New York, NY: John Wiley &

Sons, Inc. 413 p.

Hahn, J.T.; Hansen, M.H. 1984. Cubic

and board foot volume models for the

Central States. Northern Journal of

Applied Forestry. 8(2): 47-57.

Hanks, L.F. 1976. Hardwood tree grades

for factory lumber. Res. Paper NE-333.

Broomall, PA: U.S. Department of

Agriculture, Forest Service. Northeastern Forest Experiment Station. 81 p.

Hansen, M.H. 1990. A comprehensive

sampling system for forest inventory

based on an individual tree growth

model. St. Paul, MN: University of

Minnesota, College of Natural Resources. 256 p. Ph.D. dissertation.

Haugen, David E.; Piva, Ronald J.;

Kingsley, Neal P.; Harsel, Robert A.

1999. North Dakota’s forest resources,

1994. Res. Pap. NC-336. St. Paul, MN:

U.S. Depatment of Agriculture, Forest

Service, North Central Research Station.

101 p.

Little, E.L. 1981. Checklist of native and

naturalized trees of the United States.

Agric. Handb. 541. Washington, DC:

U.S. Department of Agriculture, Forest

Service. 385 p.

Loetsch, F.; Haller, K.E. 1964. Forest

inventory, volume 1, Statistics of forest

inventory and information from aerial

photographs. Vienna: BLV

Verlagsgesellschaft Munch Basle. 436 p.

Rast, E.D.; Sonderman, D.L.; Gammon,

G.L. 1973. A guide to hardwood log

grading. Gen. Tech. Rep. NE-1. Upper

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

Experiment Station. 31 p.

Smith, W.B. 1983. Adjusting the STEMS

regional growth models to improve

local predictions. Res. Note NC-297. St.

Paul, MN: U.S. Department of Agriculture, Forest Service, North Central

Forest Experiment Station. 5 p.

U.S. Department of Agriculture, Soil

Conservation Service. 1991. Instructions for collecting 1992 National

Resources Inventory sample data.

Washington, DC: U.S. Department of

Agriculture, Soil Conservation Service.

69 p.

Van Deusen, P.C.; Dell, T.R.; Thomas, C.E.

1986. Volume growth estimation from

permanent horizontal points. Forest

Science. 32: 415-422.

Wiant, H.V., Jr.; Castenaeda, F. 1977.

Mesavage and Girard’s volume tables

formulated. BLM4. Denver, CO: U.S.

Department of the Interior, Bureau of

Land Management, Denver Service

Center: 1-4.

33
TABLE TITLES

Table 1.—Area of land by major land-use

class, North and South Dakota, BIA lands,

1994 and 1996

Table 2.—Area of timberland by forest

type group/local type and stand-size class,

North Dakota BIA, 1994

Table 2a.—Area of timberland by forest

type group/local type and stand-size class,

South Dakota BIA, 1996

Table 3.—Area of timberland by Forest

Survey Unit and potential productivity

class, North and South Dakota BIA, 1994

and 1996

Table 4.—Area of timberland by stocking

class of growing-stock trees, North and

South Dakota BIA, 1994 and 1996

Table 5.—Number of all live trees on

timberland by species group and diameter

class, North Dakota BIA, 1994

Table 5a.—Number of all live trees on

timberland by species group and diameter

class, South Dakota BIA, 1996

Table 6.—Net volume of growing stock on

timberland by species group and diameter

class, North Dakota BIA, 1994

Table 6a.—Net volume of growing stock

on timberland by species group and

diameter class, South Dakota BIA, 1996

Table 7.—Net volume of growing stock

and sawtimber on timberland by major

species group, North and South Dakota

BIA, 1994 and 1996

Table 8.—Net volume of growing stock on

timberland by species group and local

forest type, North Dakota BIA, 1994

Table 8a.—Net volume of growing stock

on timberland by species group and local

forest type, South Dakota BIA, 1996

Table 9.—Net volume of sawtimber on

timberland by species group and diameter

class, North Dakota BIA, 1994

Table 9a.—Net volume of sawtimber on

timberland by species group and diameter

class, South Dakota BIA, 1996

Table 10.—Net volume of sawtimber on

timberland by species group and grade,

North Dakota BIA, 1994

Table 10a.—Net volume of sawtimber on

timberland by species group and grade,

South Dakota BIA, 1996

Table 11.—Average annual net growth of

growing stock and sawtimber on timberland by Forest Survey Unit and major

species group, North and South Dakota

BIA, 1980-1993

Table 12.—Average annual removals of

growing stock and sawtimber on timberland by Forest Survey Unit and major

species group, North and South Dakota

BIA, 1980-1993

Table 13.—Average annual net growth

and average annual removals of growing

stock and sawtimber on timberland by

species group, North Dakota BIA, 1980-

1993

Table 13a.—Average annual net growth

and average annual removals of growing

stock and sawtimber on timberland by

species group, South Dakota BIA, 1980-

1993

Table 14.—Average annual mortality of

growing stock and sawtimber on timberland by species group, North Dakota BIA,

1980-1993

Table 14a.—Average annual mortality of

growing stock and sawtimber on timberland by species group, South Dakota BIA,

1980-1993

Table 15.—Average annual net growth and

average annual removals of growing stock

and sawtimber on timberland by forest type

group/local type and major species group,

North Dakota BIA, 1980-1993

Table 15a.—Average annual net growth

and average annual removals of growing

stock and sawtimber on timberland by

forest type group/local type and major

species group, South Dakota BIA, 1980-

1993

Table 16.—All live aboveground tree

biomass on timberland by major species

group, and tree biomass component, North

and South Dakota BIA, 1994 and 1996

Table 17.—Sampling errors for Forest

Survey Unit totals for area of timberland,

volume, average annual net growth, and

average annual removals on timberland,

North and South Dakota BIA, 1994 and

1996

34
TABLES

35

36

Table 1.--Area of land by major land-use class, North and South Dakota, BIA lands, 1994 and 1996

(In thousand acres)

Total 1 Forest land

land Total Nonforest Other 2

Forest Survey Unit area forest Timberland Woodland with trees land

North Dakota BIA lands 56.6 47.6 38.8 8.8 4.8 4.2

South Dakota BIA lands 165.4 98.5 92.5 6.0 52.1 14.7

BIA total 222.0 146.1 131.3 14.8 56.9 18.9

1

 From U. S. Bureau of the Census, 1990 . 2 Includes 400 acres of water according to FIA standards of area classification, but defined by the Bureau of the Census as lan
37

Table 2.--Area of timberland by forest type group/local type and stand-size class, North Dakota BIA, 1994

(In thousand acres)

Stand-size class

Forest type group/ All Sapling- Nonlocal type stands Sawtimber Poletimber Seedling stocked

Ponderosa pine

Ponderosa pine -- -- -- -- -- 

 Total -- -- -- -- -- 

Rocky Mountain juniper 

Rocky Mountain juniper -- -- -- -- -- 

 Total -- -- -- -- -- 

Oak-hickory

Bur oak 12.8 4.0 4.6 4.2 -- 

 Total 12.8 4.0 4.6 4.2 -- 

Elm-ash-cottonwood 

Cottonwood -- -- -- -- -- 

Elm-ash-cottonwood -- -- -- -- -- 

Willow -- -- -- -- -- 

 Total -- -- -- -- -- 

Maple-beech-birch

Basswood -- -- -- -- -- 

 Total -- -- -- -- -- 

Aspen-birch

Aspen-birch 22.4 1.7 13.4 7.3 -- 

 Total 22.4 1.7 13.4 7.3 -- 

Elm-ash-locust 

Elm-ash 3.6 1.5 -- 2.1 -- 

 Total 3.6 1.5 -- 2.1 -- 

Nonstocked -- -- -- -- -- 

All types 38.8 7.2 18.0 13.6 -- 
38

Table 2a.--Area of timberland by forest type group/local type and stand-size class, South Dakota BIA, 1996

(In thousand acres)

Stand-size class

Forest type group/ All Sapling- Nonlocal type stands Sawtimber Poletimber Seedling stocked

Ponderosa pine

Ponderosa pine 41.3 19.9 9.3 12.1 -- 

 Total 41.3 19.9 9.3 12.1 -- 

Rocky Mountain juniper 

Rocky Mountain juniper 1.4 -- -- 1.4 -- 

 Total 1.4 -- -- 1.4 -- 

Oak-hickory

Bur oak 21.2 1.6 6.5 13.1 -- 

 Total 21.2 1.6 6.5 13.1 -- 

Elm-ash-cottonwood 

Cottonwood 6.7 4.2 2.5 -- -- 

Elm-ash-cottonwood 2.4 0.6 0.9 0.9 -- 

Willow 2.1 2.1 -- -- -- 

 Total 11.2 6.9 3.4 0.9 -- 

Maple-beech-birch

Basswood 3.9 2.2 1.7 -- -- 

 Total 3.9 2.2 1.7 -- -- 

Aspen-birch

Aspen-birch -- -- -- -- -- 

 Total -- -- -- -- -- 

Elm-ash-locust 

Elm-ash 12.8 3.7 2.6 6.5 -- 

 Total 12.8 3.7 2.6 6.5 -- 

Nonstocked 0.7 -- -- -- 0.7

All types 92.5 34.3 23.5 34.0 0.7
39

Table 4.--Area of timberland by stocking class of growing-stock trees 1 , 

North and South Dakota BIA, 1994 and 1996

(In thousand acres)

Stocking class of growing-stock trees

All Non- Poorly Moderately Fully OverForest Survey Unit classes stocked stocked stocked stocked stocked

North Dakota BIA lands 38.8 2.5 12.9 11.8 11.6 -- 

South Dakota BIA lands 92.5 8.8 60.3 18.9 4.5 -- 

BIA total 131.3 11.3 73.2 30.7 16.1 -- 

1 This table is based on the stocking percent of growing-stock trees, rather than that of "live" trees. For this table, to use the definition of 

 stocking found in the appendix, replace the term "live trees" with "growing-stock trees."

Table 3.--Area of timberland by Forest Survey Unit and potential productivity class,

North and South Dakota BIA, 1994 and 1996

(In thousand acres)

All Potential productivity class

Forest Survey Unit classes 85+ 50-84 20-49

North Dakota BIA lands 38.8 1.5 14.5 22.8

South Dakota BIA lands 92.5 0.2 12.5 79.8

BIA total 131.3 1.7 27 102.6
40

Table 5.--Number of all live trees on timberland by species group and diameter class, North Dakota BIA, 1994

(In thousand trees)

Diameter class (inches at breast height)

Species group All classes 1.0-2.9 3.0-4.9 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+

Hardwoods

Bur oak 3,505 1,609 746 452 277 205 110 80 15 8 3 -- -- 

Basswood 63 51 -- -- -- -- -- -- 6 6 -- -- -- 

Elm 681 345 123 189 -- 11 4 4 1 -- -- 4 -- 

Green ash 4,290 2,835 957 263 129 90 -- 15 -- -- -- 1 -- 

Cottonwood 51 51 -- -- -- -- -- -- -- -- -- -- -- 

Balsam poplar 963 357 159 127 151 95 49 20 5 -- -- -- -- 

Quaking aspen 8,577 4,197 1,698 1,275 648 413 275 57 12 -- 2 -- -- 

Paper birch 129 102 -- -- 17 -- 10 -- -- -- -- -- -- 

Other hardwoods 747 612 -- 41 38 -- 10 20 10 4 12 -- -- 

 Total hardwoods 19,006 10,159 3,683 2,347 1,260 814 458 196 49 18 17 5 -- 

Noncommercial species 3,052 2,913 131 -- -- -- -- -- -- -- -- 8 -- 

All species 22,058 13,072 3,814 2,347 1,260 814 458 196 49 18 17 13 -- 

Table 5a.--Number of all live trees on timberland by species group and diameter class, South Dakota BIA, 1996

(In thousand trees)

Diameter class (inches at breast height)

Species group All classes 1.0-2.9 3.0-4.9 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 pine 11,791 4,195 2,740 1,524 1,249 995 459 252 174 113 56 34 -- 

Other softwoods 1,709 1,182 398 88 3 29 -- 7 1 -- -- 1 -- 

 Total softwoods 13,500 5,377 3,138 1,612 1,252 1,024 459 259 175 113 56 35 -- 

Hardwoods

Bur oak 3,028 166 1,047 850 522 244 100 44 23 12 6 6 8

Basswood 632 153 51 108 60 111 103 18 9 19 -- -- -- 

Elm 1,933 1,204 377 95 154 32 35 25 8 -- 1 2 -- 

Green ash 3,316 1,291 903 549 316 144 74 14 18 5 -- 2 -- 

Cottonwood 474 51 -- 169 82 -- 18 20 31 9 -- 66 28

Willow 154 51 -- 39 16 -- 17 31 -- -- -- -- -- 

Hackberry 55 12 12 -- 29 -- 2 -- -- -- -- -- -- 

Black cherry 1 -- -- -- -- -- -- -- -- -- -- 1 -- 

Other hardwoods 1,103 424 236 214 124 21 51 24 4 5 -- -- -- 

 Total hardwoods 10,696 3,352 2,626 2,024 1,303 552 400 176 93 50 7 77 36

Noncommercial species 3,456 3,040 338 47 -- 6 11 7 3 1 2 1 -- 

All species 27,652 11,769 6,102 3,683 2,555 1,582 870 442 271 164 65 113 36
41

Table 6.--Net volume of growing stock on timberland by species group and diameter class, North Dakota BIA, 1994

(In thousand cubic feet)

Diameter class (inches at breast height)

Species group 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+

Hardwoods

Bur oak 3,792 627 773 993 835 326 110 -- 128 -- -- 

Basswood 163 -- -- -- -- -- 163 -- -- -- -- 

Elm 587 239 -- -- -- -- -- -- -- 348 -- 

Green ash 982 369 180 274 -- 159 -- -- -- -- -- 

Balsam poplar 3,171 298 713 947 651 411 151 -- -- -- -- 

Quaking aspen 11,874 2,613 2,911 3,024 2,545 713 68 -- -- -- -- 

Other hardwoods 1 442 79 107 -- 122 134 -- -- -- -- -- 

 Total hardwoods 21,011 4,225 4,684 5,238 4,153 1,743 492 -- 128 348 -- 

All species 21,011 4,225 4,684 5,238 4,153 1,743 492 -- 128 348 -- 

1

 All other hardwood growing-stock volume is boxelder.

Table 6a.--Net volume of growing stock on timberland by species group and diameter class, South Dakota BIA, 1996

(In thousand cubic feet)

Diameter class (inches at breast height)

Species group 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 pine 33,801 2,384 4,023 6,346 4,662 4,247 4,066 3,647 2,462 1,964 -- 

Other softwoods 23 23 -- -- -- -- -- -- -- -- -- 

 Total softwoods 33,824 2,407 4,023 6,346 4,662 4,247 4,066 3,647 2,462 1,964 -- 

Hardwoods 

Bur oak 4,807 744 1,302 1,239 583 155 177 34 127 160 287

Basswood 3,053 161 129 491 955 107 116 365 -- 365 365

Elm 1,429 76 533 92 358 370 -- -- -- -- -- 

Green ash 2,652 434 665 553 156 211 282 117 -- 117 117

Cottonwood 15,843 1,652 2,089 -- 1,346 1,756 2,983 2,006 -- 2,006 2,006

Willow 274 60 -- -- 100 114 -- -- -- -- -- 

Hackberry 72 -- 50 -- 22 -- -- -- -- -- -- 

Black cherry 91 91 -- -- -- -- -- -- -- -- -- 

Other hardwoods 1 649 199 321 18 111 -- -- -- -- -- -- 

 Total hardwoods 28,870 3,417 5,089 2,393 3,631 2,713 3,558 2,522 127 2,648 2,775

All species 62,694 5,824 9,112 8,739 8,293 6,960 7,624 6,169 2,589 4,612 2,775

1

 All other hardwood growing-stock volume is boxelder.
42

 Growing stock

Major species group

Other Soft Hard

Forest Survey Unit All species Pine softwoods hardwoods hardwoods

North Dakota BIA 21,011 -- -- 16,237 4,774

South Dakota BIA 62,694 33,801 23 21,411 7,459

BIA total 83,705 33,801 23 37,648 12,233

Sawtimber

Major species group

Other Soft Hard

Forest Survey Unit All species Pine softwoods hardwoods hardwoods

North Dakota BIA 30,068 -- -- 23,375 6,693

South Dakota BIA 234,494 135,048 -- 86,528 12,918

BIA total 264,562 135,048 -- 109,903 19,611

1

 International 1/4-inch rule.

(In thousand board feet) 1

(In thousand cubic feet)

Table 7.--Net volume of growing stock and sawtimber on timberland by 

major species group, North and South Dakota BIA, 1994 and 1996
43

Table 8.--Net volume of growing stock on timberland by species group and local forest type, North Dakota BIA, 1994

(In thousand cubic feet)

Local forest type

Rocky

All Ponderosa Mountain Elm-ash- AspenSpecies group types pine juniper Bur oak Cottonwood cottonwood Basswood birch Elm-ash

Hardwoods

Bur oak 3,792 -- -- 3,339 -- -- -- 453 -- 

Basswood 163 -- -- 163 -- -- -- -- -- 

Elm 587 -- -- -- -- 379 -- 208 -- 

Green ash 982 -- -- 497 -- 116 -- 369 -- 

Balsam poplar 3,171 -- -- 462 -- -- -- 2,709 -- 

Quaking aspen 11,874 -- -- 434 -- -- -- 11,440 -- 

Other hardwoods 1 442 -- -- -- -- 442 -- -- -- 

 Total hardwoods 21,011 -- -- 4,895 -- 937 -- 15,179 -- 

All species 21,011 -- -- 4,895 -- 937 -- 15,179 -- 

1 All other hardwood volume is boxelder.
44

Table 8a.--Net volume of growing stock on timberland by species group and local forest type, South Dakota BIA, 1996

(In thousand cubic feet)

Local forest type

Rocky

All Ponderosa Mountain Elm-ashSpecies group types pine juniper Bur oak Cottonwood Willow cottonwood Basswood Elm-ash

Softwoods 

Ponderosa pine 33,801 27,260 664 5,577 -- -- -- -- 300

Other softwoods 23 9 14 -- -- -- -- -- -- 

 Total softwoods 33,824 27,269 678 5,577 -- -- -- -- 300

Hardwoods 

Bur oak 4,807 127 -- 3,041 -- -- 35 101 1,503

Basswood 3,053 -- -- -- -- -- -- 2,748 305

Elm 1,429 -- -- 368 -- 39 14 173 835

Green ash 2,652 109 -- 545 138 -- 400 473 987

Cottonwood 15,843 -- -- -- 7,499 -- 1,121 -- 7,223

Willow 274 -- -- -- -- 274 -- -- -- 

Hackberry 72 -- -- 22 -- -- -- -- 50

Black cherry 91 -- -- -- -- -- 91 -- -- 

Other hardwoods 1 649 -- -- -- -- -- 35 111 503

 Total hardwoods 28,870 236 -- 3,976 7,637 313 1,696 3,606 11,406

All species 62,694 27,505 678 9,553 7,637 313 1,696 3,606 11,706

1 All other hardwood volume is boxelder.
45

Table 9.--Net volume of sawtimber on timberland by species group and diameter class, North Dakota BIA, 1994

Diameter class (inches at breast height)

Species group All classes 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+

Hardwoods

Bur oak 5,978 3,405 1,443 515 -- 615 -- -- 

Basswood 788 -- -- 788 -- -- -- -- 

Elm 1,716 -- -- -- -- -- 1,716 -- 

Green ash 715 -- 715 -- -- -- -- -- 

Balsam poplar 5,347 2,788 1,845 714 -- -- -- -- 

Quaking aspen 14,445 10,849 3,276 320 -- -- -- -- 

Other hardwoods 2 1,079 483 596 -- -- -- -- -- 

 Total hardwoods 30,068 17,525 7,875 2,337 -- 615 1,716 -- 

All species 30,068 17,525 7,875 2,337 -- 615 1,716 -- 

1 International 1/4-inch rule. 2 All other hardwood volume is boxelder.

(In thousand board feet) 1

Table 9a.--Net volume of sawtimber on timberland by species group and diameter class, South Dakota BIA, 1996

Diameter class (inches at breast height)

Species group 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 pine 135,048 29,264 22,362 20,967 20,628 18,740 12,726 10,361 -- 

 Total softwoods 135,048 29,264 22,362 20,967 20,628 18,740 12,726 10,361 -- 

Hardwoods 

Bur oak 8,961 -- 2,550 690 791 151 574 333 3,872

Basswood 10,597 -- 6,467 740 814 2,576 -- -- -- 

Elm 3,162 -- 1,513 1,649 -- -- -- -- -- 

Green ash 3,957 -- 690 982 1,375 593 -- 317 -- 

Cottonwood 70,956 -- 1,114 1,559 2,724 1,862 -- 25,448 38,249

Willow 774 -- 353 421 -- -- -- -- -- 

Hackberry 99 -- 99 -- -- -- -- -- -- 

Black cherry 485 -- -- -- -- -- -- 485 -- 

Other hardwoods 2 455 -- 455 -- -- -- -- -- -- 

 Total hardwoods 99,446 -- 13,241 6,041 5,704 5,182 574 26,583 42,121

All species 234,494 29,264 35,603 27,008 26,332 23,922 13,300 36,944 42,121

1 International 1/4-inch rule.

2

 All other hardwood volume is boxelder.

(In thousand board feet) 1
46

Table 10.--Net volume of sawtimber on timberland by species group and grade,

North Dakota BIA, 1994

Tree grade

Tie &

Species group Total 1 2 3 timber

Hardwoods 

Bur oak 5,978 -- 449 962 4,567

Basswood 788 788 -- -- -- 

Elm 1,716 1,716 -- -- -- 

Green ash 715 -- -- 715 -- 

Balsam poplar 5,347 -- 1,296 1,116 2,935

Quaking aspen 14,445 -- 680 10,109 3,656

Other hardwoods 2 1,079 -- -- -- 1,079

 Total hardwoods 30,068 2,504 2,425 12,902 12,237

All species 30,068 2,504 2,425 12,902 12,237

1 International 1/4-inch rule. 2 All other hardwood volume is boxelder.

(In thousand board feet) 1
47

Table 10a.--Net volume of sawtimber on timberland by species group and grade,

South Dakota BIA, 1996

Log grade

Species group Total 1 2 3 4

Softwoods 

Ponderosa pine 135,048 418 5,485 129,144 -- 

 Total softwoods 135,048 418 5,485 129,144 -- 

Tree grade

Tie &

Species group Total 1 2 3 timber

Hardwoods 

Bur oak 8,961 -- 4836 309 3,816

Basswood 10,597 -- 3,765 6,832 -- 

Elm 3,162 -- -- 3,162 -- 

Green ash 3,957 -- -- 2,741 1,216

Cottonwood 70,956 43,858 8,142 15,167 3,789

Willow 774 -- -- 353 421

Hackberry 99 -- -- 99 -- 

Black cherry 485 -- -- 485 -- 

Other hardwoods 2 455 -- -- -- 455

 Total hardwoods 99,446 43,858 16,743 29,148 9,697

All species 234,494 44,276 22,228 158,292 9,697

1

 International 1/4-inch rule.

2 All other hardwood volume is boxelder.

(In thousand board feet) 1
48

Growing stock

Major species group

Other Soft Hard

Forest Survey Unit All species Pine softwoods hardwoods hardwoods

(In thousand cubic feet)

North Dakota BIA lands 684 -- -- 548 136

South Dakota BIA lands 975 559 10 148 258

BIA total 1,659 559 10 696 394

Sawtimber

Major species group

Other Soft Hard

Forest Survey Unit All species Pine softwoods hardwoods hardwoods

North Dakota BIA lands 850 -- -- 649 201

South Dakota BIA lands 3,037 2,375 3 256 403

BIA total 3,887 2,375 3 905 604

1

 International 1/4-inch rule .

(In thousand board feet) 1

Table 11.--Average annual net growth of growing stock and sawtimber on timberland by

Forest Survey Unit and major species group, North and South Dakota BIA, 1980-1993
49

Growing stock

Major species group

Other Soft Hard

Forest Survey Unit All species Pine softwoods hardwoods hardwoods

(In thousand cubic feet)

North Dakota BIA lands 54 -- -- 37 17

South Dakota BIA lands 89 5 1 44 39

BIA total 143 5 1 81 56

Sawtimber

Major species group

Other Soft Hard

Forest Survey Unit All species Pine softwoods hardwoods hardwoods

North Dakota BIA lands -- -- -- -- -- 

South Dakota BIA lands 256 -- 4 198 54

BIA total 256 -- 4 198 54

1 International 1/4-inch rule

(In thousand board feet) 1

Table 12.--Average annual removals of growing stock and sawtimber on timberland by Forest Survey Unit

and major species group, North and South Dakota BIA, 1980-1993
50

Table 13.--Average annual net growth and average annual removals of growing stock and sawtimber

on timberland by species group, North Dakota BIA, 1980-1993

Growing stock Sawtimber

Average annual Average annual Average annual Average annual

Species group net growth removals net growth removals

(In thousand cubic feet)

Hardwoods

Bur oak 81 -- 195 -- 

Basswood -- -- 3 -- 

Elm -2 -- -203 -- 

Green ash 55 17 6 -- 

Balsam poplar 74 -- 273 -- 

Quaking aspen 457 37 535 -- 

Other hardwoods 2 19 -- 41 -- 

 Total hardwoods 684 54 850 -- 

All species 684 54 850 -- 

1 International 1/4-inch rule. 2 All other hardwood volume is boxelder.

(In thousand board feet) 1
51

Table 13a.--Average annual net growth and average annual removals of growing stock and sawtimber

on timberland by species group, South Dakota BIA, 1980-1993

Growing stock Sawtimber

Average annual Average annual Average annual Average annual

Species group net growth removals net growth removals

(In thousand cubic feet)

Softwoods 

Ponderosa pine 559 5 2,375 -- 

Other softwoods 10 1 3 4

 Total softwoods 569 6 2,378 4

Hardwoods

Bur oak 157 2 107 10

Basswood 68 3 290 15

Elm 5 30 -111 138

Green ash 101 37 296 44

Cottonwood 50 -- -13 -- 

Willow 17 -- 41 -- 

Hackberry 4 -- 4 -- 

Black cherry 1 -- -- -- 

Other hardwoods 2 3 11 45 45

 Total hardwoods 406 83 659 252

All species 975 89 3,037 256

1 International 1/4-inch rule. 2 All other hardwood volume is boxelder.

(In thousand board feet) 1
52

Table 14.--Average annual mortality of growing stock and sawtimber

on timberland by species group, North Dakota BIA, 1980-1993

Growing stock Sawtimber

Species group average annual mortality average annual mortality

(In thousand cubic feet)

Bur oak -- -- 

Basswood -- -- 

Elm 49 217

Green ash 2 -- 

Balsam poplar 77 107

Quaking aspen 277 383

Other hardwoods 2 6 14

All species 411 721

1

 International 1/4-inch rule.

2

 All other hardwood volume is boxelder.

(In thousand board feet) 1
53

Table 14a.--Average annual mortality of growing stock and sawtimber

on timberland by species group, South Dakota BIA, 1980-1993

Growing stock Sawtimber

Species group average annual mortality average annual mortality

(In thousand cubic feet)

Softwoods 

Ponderosa pine 204 925

 Total softwoods 204 925

Hardwoods

Bur oak 11 53

Basswood 47 111

Elm 99 296

Green ash 52 50

Cottonwood 300 1,254

Willow 7 23

Hackberry 1 1

Other hardwoods 2 28 8

 Total hardwoods 545 1,796

All species 749 2,721

1

 International 1/4-inch rule. 2

 All other hardwood volume is boxelder.

(In thousand board feet) 1
54

Table 15.--Average annual net growth and average annual removals of growing stock and sawtimber on timberland

by forest type group/local type and major species group, North Dakota BIA, 1980-1993

Average annual net growth of growing stock Average annual removals of growing stock

Major species group Major species group

Forest type group/ All Other Soft Hard All Other Soft Hard

local type species Pine softwoods hardwoods hardwoods species Pine softwoods hardwoods hardwoods

(In thousand cubic feet) (In thousand cubic feet)

Oak-hickory

Bur oak 86 -- -- 7 79 -- -- -- -- -- 

 Total 86 -- -- 7 79

Aspen-birch

Aspen-birch 592 -- -- 551 41 54 -- -- 37 17

 Total 592 -- -- 551 41 54 -- -- 37 17

Elm-ash-locust 

Elm-ash 6 -- -- -10 16 -- -- -- -- -- 

 Total 6 -- -- -10 16 -- -- -- 

All forest types 684 -- -- 548 136 54 -- -- 37 17

Average annual net growth of sawtimber Average annual removals of sawtimber

Major species group Major species group

Forest type group/ All Other Soft Hard All Other Soft Hard

local type species Pine softwoods hardwoods hardwoods species Pine softwoods hardwoods hardwoods

(In thousand board feet) 1 (In thousand board feet) 1

Oak-hickory

Bur oak 129 -- -- -72 201 -- -- -- -- -- 

 Total 129 -- -- -72 201 -- -- -- -- -- 

Aspen-birch

Aspen-birch 833 -- -- 833 -- -- -- -- -- -- 

 Total 883 -- -- 833 -- -- -- -- -- -- 

Elm-ash-locust 

Elm-ash -112 -- -- -112 -- -- -- -- -- -- 

 Total -112 -- -- -112 -- -- -- -- -- -- 

All forest types 850 -- -- 649 201 -- -- -- -- -- 1 International 1/4-inch rule.
55

Table 15a.--Average annual net growth and average annual removals of growing stock and sawtimber on timberland

by forest type group/local type and major species group, South Dakota BIA, 1980-1993

Average annual net growth of growing stock Average annual removals of growing stock

Major species group Major species group

Forest type group/ All Other Soft Hard All Other Soft Hard

local type species Pine softwoods hardwoods hardwoods species Pine softwoods hardwoods hardwoods

(In thousand cubic feet) (In thousand cubic feet)

Ponderosa pine 

Ponderosa pine 452 432 8 -5 17 5 5 -- -- -- 

 Total 452 432 8 -5 17 5 5 -- -- -- 

Rocky Mountain juniper 

Rocky Mountain juniper 18 14 2 1 1 1 -- 1 -- -- 

 Total 18 14 2 1 1 1 -- 1 -- -- 

Oak-hickory

Bur oak 282 98 -- 17 167 -- -- -- -- -- 

 Total 282 98 -- 17 167 -- -- -- -- -- 

Elm-ash-cottonwood

Cottonwood 153 -- -- 148 5 -- -- -- -- -- 

Willow 18 -- -- 18 -- -- 

Elm-ash-cottonwood 41 -- -- 30 11 66 -- -- 41 25

 Total 212 -- -- 196 16 66 -- -- 41 25

Maple-beech-birch

Basswood 76 -- -- 67 9 -- -- -- -- -- 

 Total 76 -- -- 67 9 -- -- -- -- -- 

Elm-ash-locust 

Elm-ash -65 15 -- -128 48 17 - - 3 14

 Total -65 15 -- -128 48 17 - - 3 14

All forest types 975 559 10 148 258 89 5 1 44 39

Average annual net growth of sawtimber Average annual removals of sawtimber

Major species group Major species group

Forest type group/ All Other Soft Hard All Other Soft Hard

local type species Pine softwoods hardwoods hardwoods species Pine softwoods hardwoods hardwoods

(In thousand board feet) 1 (In thousand board feet) 1

Ponderosa pine 

Ponderosa pine 1,825 1,845 -- -20 -- -- -- -- -- -- 

 Total 1,825 1,845 -- -20 -- -- -- -- -- -- 

Rocky Mountain juniper 

Rocky Mountain juniper 157 152 3 2 -- 4 -- 4 -- -- 

 Total 157 152 3 2 -- 4 -- 4 -- -- 

Oak-hickory

Bur oak 401 318 -- 1 82 -- -- -- -- -- 

 Total 401 318 -- 1 82 -- -- -- -- -- 

Elm-ash-cottonwood

Cottonwood 494 -- -- 494 -- -- -- -- -- -- 

Willow 41 -- -- 41 -- -- -- -- -- -- 

Elm-ash-cottonwood 102 -- -- 109 -7 183 -- -- 183 -- 

 Total 637 -- -- 644 -7 183 -- -- 183 -- 

Maple-beech-birch

Basswood 244 -- -- 228 16 -- -- -- -- -- 

 Total 244 -- -- 228 16 -- -- -- -- -- 

Elm-ash-locust 

Elm-ash -227 60 -- -599 312 69 -- -- 15 54

 Total -227 60 -- -599 312 69 -- -- 15 54

All forest types 3,037 2,375 3 256 403 256 -- 4 198 54

1 International 1/4-inch rule.
56

Table 16.--All live aboveground tree biomass on timberland by major species group, and 

 tree biomass component, North and South Dakota BIA, 1994 and 1996

(In green tons)

Tree biomass component

Growing-stock trees Non-growing-stock trees

Ownership class and All All Tops Tops

major species group Components 1-5 inch trees Stumps Boles and limbs Stumps Boles and limbs

North Dakota BIA lands 

Soft hardwoods 1,184,331 125,441 37,358 510,571 147,830 19,342 272,264 71,525

Hard hardwoods 604,996 97,054 18,757 168,187 59,546 18,851 182,363 60,238

 Total 1,789,327 222,495 56,115 678,758 207,376 38,193 454,627 131,763

South Dakota BIA lands

Pine 1,208,717 75,072 77,014 868,815 97,040 7,562 74,397 8,817

Other softwoods 35,294 14,135 113 580 227 1,801 14,448 3,990

Soft hardwoods 1,195,385 54,679 48,955 625,640 149,706 21,291 228,378 66,736

Hard hardwoods 952,988 93,139 26,552 247,183 82,394 37,074 350,545 116,101

 Total 3,392,384 237,025 152,634 1,742,218 329,367 67,728 667,768 195,644

Table 17.--Sampling errors for Forest Survey Unit totals for area of timberland, volume, average annual net growth,

and average annual removals on timberland, North and South Dakota BIA, 1994, and 1996

(Sampling error in percent)

Growing stock Sawtimber

Average Average Average Average

annual net annual annual net annual

Forest Survey Unit Area Volume growth removals Volume growth removals

North Dakota BIA 14.8 24.6 28.3 136.6 38.9 57.4 -- 

South Dakota BIA 6.7 7.8 16.9 70.6 12.4 23.0 69.0

BIA total 6.4 8.5 15.0 67.8 11.9 21.9 69.0
MISSION STATEMENT

We believe the good life has its roots in clean air, sparkling water, rich soil,

healthy economies and a diverse living landscape. Maintaining the good

life for generations to come begins with everyday choices about natural

resources. The North Central Research Station provides the knowledge

and the tools to help people make informed choices. That’s how the

science we do enhances the quality of people’s lives.

For further information contact:

North Central Research Station

USDA Forest Service

1992 Folwell Ave.

St. Paul, MN 55108

Or visit our web site:

www.ncrs.fs.fed.us

The Forest Inventory and Analysis web site is:

www.fia.fs.fed.us
Printed on recyclable paper

The U.S. Department of Agriculture (USDA) prohibits

discrimination in all its programs and activities on the

basis of race, color, national origin, gender, religion, age,

disability, political beliefs, sexual orientation, and marital

or family status. (Not 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

and TDD).

To file a complaint of discrimination, write USDA,

Director, Office of Civil Rights, Room 326-W, Whitten

Building, 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.
Haugen, David E.; Hansen, Mark H.

2002. BIA forest lands of North and South Dakota, 1996. Resour. Bull. NC202. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North

Central Research Station. 56 p.

An estimated 146 thousand acres of forest land are under BIA jurisdiction,

and 131 thousand acres of that are forest land and timberland. This bulletin

contains detailed tables of area, volume, growth, removals, and mortality on

timberland.

KEY WORDS: Forest area, timber volume, growth, removals, mortality, BIA.