Forest statistics for Iowa, 1990

110 Pages·1991·5 MB·English

by  Brand, Gary J

document
Historic, archived
Do not assume content reflects current
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40 Ull
/93$
United States Forest Statistics
Department of
i
Agriculture
990
Forest for Iowa,
1
Service
North Central
Forest Experiment
Station
Resource
Bulletin NC-136 Gary J. Brand and John T. Walkowiak
<S3
North Central Forest Experiment Station
—
Forest Service U.S. Department ofAgriculture
1992 Folwell Avenue
St. Paul, Minnesota 55108
Manuscript approved for publication December 16, 1991
1991
This report includes the most commonly used Forest Inventory andAnaly-
sis statistics. Additional forest resource data can be provided to interested
users. Persons requesting additional information that can be provided
from the raw inventory data are expected to paythe retrieval costs. These
costs range from less than $100 for a simple request to $2,000 for a com-
plex retrieval involving the services ofa Forest Inventory and Analysis
computer programmer. Requests will be filled to minimize the impact on
the Forest Inventory and Analysis Work Unit.
Requests for unpublished information may be directed to:
Project Leader
Forest Inventory and Analysis
North Central Forest Experiment Station
1992 FolwellAvenue
St. Paul, Minnesota 55108
Phone: [phone]
or
State Forester
Iowa Department ofNatural Resources
Wallace State Office Building
East 9th & Grand Avenue
Des Moines, Iowa 50319
Area served: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Mis-
souri, Nebraska, North Dakota, South Dakota, Wisconsin
We thank Caren Robey ofDes Moines, Iowa, forthe drawing on the front
cover.
FOREWORD
Forest Inventory andAnalysis is a continuing endeavor mandated by the
Renewable Forest and Rangeland Resources PlanningAct of 1974. Prior
inventories were mandated by the McSweeney-McNary Forest Research Act
of 1928. The objective ofForest Inventory andAnalysis is to periodically
inventory the Nation's forest land to determine its extent, condition, volume
oftimber, growth, and removals. Up-to-date resource information is essen-
tial to frame forest policies and programs. USDAForest Service regional
experiment stations are responsible for conducting these inventories and
publishing summary reports for individual States. The North Central
Forest Experiment Station is responsible for Forest Inventory and Analysis
in Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Ne-
braska, North Dakota, South Dakota, and Wisconsin.
Field work for the Iowa forest inventory began in May 1989 and ended in
February 1990. Reports ofthe two previous inventories ofIowa's timber
resource are dated 1954 and 1974.
The USDAAgricultural Stabilization and Conservation Service provided
aerial photos used in the Iowa Forest Inventory.
Contents
Page
Highlights 1
General 1
ForestArea 1
Number ofTrees 3
Volume 4
Timber Growth, Mortality, and Removals 5
Biomass 6
Appendix 6
Accuracy ofthe Survey 6
Survey Procedures 7
Comparing Iowa's Third Inventory With The Second Inventory 12
Tree/Log Grade 12
Metric Equivalents ofUnits Used in This Report 18
Tree Species Groups in Iowa 18
Shrub Species in Iowa 19
Definition ofTerms 19
Table Titles 26

Forest Statistics For Iowa, 1990
Gary J. Brand and John T. Walkowiak
HIGHLIGHTS General
NOTE: Comparisons ofdatafrom newforest Although known today primarily as an agricul-
inventories with datafrom earlier inventories tural State, Iowa had about 7 million acres of
indicate trends inforest resources. Comparisons forest before European settlement. Agricultural
are only valid iftheprocedures used in the two clearing has dramatically reduced the area of
inventories are similar. Because ofourongoing forested land. In this report, the status of
efforts to improve the efficiency and reliability of Iowa's forests and the changes since the last
the inventory, several changes inprocedures and inventory are presented.
definitions have occurred since 1974. Some of
these changes make it inappropriate to directly Iowa is divided along county boundaries into
compare the 1990 data with thosepublishedfor three geographical areas called the Northeastern
1974. Therefore, datafrom the 1974 inventory Unit, Southeastern Unit, and Western Unit (fig.
have been reprocessed using the 1990proce- 1). White oak-red oak-hickory and maple-
dures andpublished inpart in this report. basswood are the most common forest types in
Please refer to the section labeled "Comparing the Northeastern Unit; white oak-red oak-
Iowa's ThirdInventory WithThe Second hickory forests predominate in the Southeastern
Inventory"formore details. Unit; and elm-ash-soft maple forests coverthe
most area in the less densely forested Western
Gary J. Brand, Research Forester, received a Unit.
bachelors degree in Chemical Engineering in
1971 and a masters offorestry degree in 1976 Forest Area
from the University ofMinnesota. Hejoined the
Modeling Unit at the North Central Forest • Iowa had 2.1 million acres offorested land,
Experiment Station in 1977. A detail to the or 5.7 percent ofthe State's total land area in
Forest Inventory and Analysis Unit gave him the 1990. The two eastern Survey Units had
opportunity to work on the Iowa report. most ofthe forest land and had more oftheir
landbase in forests than the Western Unit
John T. Walkowiak, Urban Forestry Coordina- did. The Northeastern, Southeastern, and
tor, received a bachelors degree from State Uni- Western Units were 8.1, 8.9, and 2.0 percent
versity ofNew York, College ofEnvironmental forested, respectively.
Sciences and Forestry in 1978 and a masters
degree in Forest Resources from the University • In 1974 forests covered only 4.3 percent (1.6
ofNew Hampshire in 1984. After receiving for- million acres) ofIowa. Although forest land
estry experience in New England, Nebraska, and increased in all Units, the lar—gest increase
Montana, hejoined the Iowa Department of was in the Southeastern Unit 41.7 percent
Natural Resources in 1989. from 1974 to 1990 (fig. 2).
——
NORTHEASTERN UNIT
X Lyon Osceola Dickinson Emm* Winnebago Wortn Howard
Kossuth
J Sioux O'Brien Clay APlatloo CGeorrrdoo Floyd Chickasaw
Buena Franklin
' Plymouth Cherokee Vista Pocahontas Humboldt Wright Bremer
Black
Woodbury Hamilton Grundy Hawk
Crawford Carroll Boone Story Marshall Benton
Sheby Audubon Dallas
Jasper
^ Pottawattamie Cass Adair Madison Warren Marion Mahaska Keokuk
Milk Montgomery Adams Clarke Monroe Wapello Jefferson
Van
Page Taylor Ringgold Decatur Wayne Appanoose Davis Buren
WESTERN UNIT SOUTHEASTERN UNIT
Figure 1. Forest Survey Units inIowa.
1.2' • Timberland in Iowa was estimated at 1.9
million acres in 1990, up from 1.5 million
1.0- 1974 acres in 1974. The 1974 to 1990 increase in
1990 timberland area reversed the sharp decline
.8- observed from 1954 to 1974. Most ofthe
w new timberland came from land formerly
o classified as pasture (improved pasture,
.6-
c wooded pasture, and improved pasture with
o
trees), but now no longer grazed.
.4-
• Farmers owned 1.2 million acres (nearly 64
-
.2 percent) ofthe timberland in Iowa in 1990
(fig. 3). Landowners classified as
o-- ,„..„,„; miscellaneous private owned an additional
Northeastern Southeastern Western 546,000 acres (about 28 percent) of
Survey Unit timberland. Public agencies administered
only 8 percent ofthe timberland in Iowa.
Figure 2. Area offorest land by ForestSurvey
'
Una, Iowa, 1974 and 1990. • As in 1974, the white oak-red oak-hickory
forest type in 1990 covered more area than
any other forest type (37 percent). It
2