Illinois' forests in 1998 [microform]

146 Pages·2000·6.8 MB·English

by  Schmidt, Thomas L

document
Historic, archived
Do not assume content reflects current
scientific knowledge, policies, or practices.
i
Forests 1998
Illinois' in Q c
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Thomas L. Schmidt, Mark H. Hansen, and James A. Solomakos
North Central
Research
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Resource Bulletin 132S Jrive
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North Central Research Station
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Forest Service U.S. Department ofAgriculture
1992 Folwell Avenue
St. Paul, Minnesota 55108
Manuscript approved for publication October 24, 2000
2000
This report includes the most commonly used U.S. Department ofAgricul-
ture, Forest Service, Forest Inventory and Analysis (FLA) statistics. Addi-
tional forest resource data can be obtained through FLA staff, an FLACD-
ROM disc, or a table generator on the North Central Research Station's
Internet page. Persons requesting additional information from FLA staffare
expected to pay the retrieval costs. Requests may be directed to:
Program Manager, FLA
North Central Research Station
1992 Folwell Avenue
St. Paul, MN 55108
[phone]
or
State Forester, Illinois Department
ofNatural Resources
Division ofForest Resources
600 North Grand Avenue West
Springfield, IL 62794-9225
[phone]
FOREWORD
FIA is a continuing endeavor as mandated by the Renewable Resources
Research Act of 1978, the Forest Ecosystems and Atmospheric Pollution Act
of 1988, and Section 253(c) ofthe Agricultural Research, Extension, and
Education Reform Act of 1998. The objective ofFIA is to inventory the
Nation's forest land. Up-to-date resource information is essential to frame
forest policies and programs. USDA Forest Service regional research stations
are responsible for conducting these inventories. Fieldwork for the fourth
forest inventory ofIllinois was begun in August of 1996 and completed in
August of 1998. Reports ofprevious inventories ofIllinois are dated 1948,
1962, and 1985. The State ofIllinois provided valuable cooperation and
assistance throughout the course ofthis most recent inventory effort.
Notice to users ofthe 1998 inventory ofIllinois's forest resources
results:
Tables in the appendix relating to sawtimbervolume are presented in both
International 1/4 inch rule and Doyle rule. International 1/4 inch rule is
the USDA Forest Service standard while Doyle is the common measure used
in Illinois by forest industries and land management agencies. Because
these results are used nationally and consistent comparisons are crucial,
International 1/4 inch rule is used as the unit ofmeasure for sawtimber
volume unless Doyle rule is noted in the text. We have made an effort to
include Doyle tables and discussion where appropriate to improve the utility
ofthe inventory results for regional and local users ofthese results.
Data from new inventories are often compared with data from earlier invento-
ries to determine trends in forest resources. However, for the comparisons to
be valid, the procedures used in the two inventories must be similar. As a
result ofour ongoing efforts to improve the efficiency and reliability ofthe
inventory, several changes in procedures and definitions have occurred since
the last Illinois inventory in 1985. Because some ofthese changes will make
it inappropriate to directly compare the 1998 data with those published for
1985, data from the 1985 inventory have been reprocessed using the 1998
procedures. Please refer to the section labeled "Comparing the fourth inven-
tory ofIllinois with the third inventory" in the appendix for more details.
Perhaps the most significant change between inventories was the develop-
ment ofnew volume tables between the 1985 and 1998 inventories ofIllinois'
forest resources. The newvolume tables, developed by USDA Forest Service
research scientists and other cooperating researchers, more accurately
estimate the true growing-stock and sawtimber volume. In general, the old
volume tables used in the previous inventories slightly overestimated the
true volume. As a part ofthe current inventory, we updated the 1985 inven-
tory using the newvolume tables. As a result, the volumes that were recal-
culated for the 1985 inventory show a small decrease from the previously
published volumes (Resource Bulletins NC-103 - Illinois Forest Statistics,
1985, and NC-105 - Illinois' Forest Resource). All tables with 1985 data, and
comparisons to the 1985 inventory results, in this publication reflect the
recalculated volumes.
Field work for this most recent inventorywas completed between 1996 and
1998. All data related to area and volume are dated 1998. Because field
measurements were ongoing during 1998 and change data such as growth,
mortality, and removals continued to occur in 1998, these data are dated
1997. Comparisons between Hie most recent inventory and updated previ-
ous inventories for area and volume compare 1985 with 1998. Compari-
sons for growth, mortality, and removals compare 1985 with 1997.
FIA St. Paul, Minnesota, staffinvolved in the fourth inventory ofIllinois
included Beth Collins, Dave Frazier, Barb Fuller, Dale Gormanson, Ron
Hackett, David Haugen, Barb Knight, Leo Larkin, Earl Leatherberry, Dennis
May, Pat Miles, Tim Miller, Jerry Ostrom, Ron Piva, Gerhard Raile, MaryJo
Resendez, Tyson Schreiner, and DanWendt. FIA field staffinvolved in this
inventorywere RyanAnderson, Joseph Boykin, Steve Fadden, Tom Forbes,
Cheri Hartless, Patrick Hartless, Glenda Hefty, Bryan Hendricks, Gary
Inhelder, Brian Peura, Brad Witkin, and Erin Witkin.
Table ofContents
Page
Highlights 1
Extent ofIllinois' Forests 1
Composition ofIllinois' Forests 3
Area 3
Number ofTrees 4
Growing-stock Volume 5
Sawtimber Volume 6
Quality ofSawtimber 6
Causes ofChange in Illinois' Forests 8
Appendix 13
PublicAccess to FIA Data 13
Accuracy ofthe 1998 Illinois Survey 13
Comparing the Fourth Inventory ofIllinois with the Third Inventory 15
Survey Procedures 15
Phase-One Stratification 16
1985 Photo Plot Sampling ofAerial Photographs 16
1998 Computer-assisted Classification ofSatellite Images 16
Phase-Two Ground Plot Measurements 17
1985 Plot Design 17
1998 Plot Design '17
Estimation 19
Current (1998) Area 20
Area Change (1985-1998) 20
Volume 20
Net Growth, Mortality, and Removals 22
Average Annual Net Growth and Mortality (1985-1997) 22
Current Net Growth and Mortality (1997) 22
Average Annual Removals (1985-1997) 22
Current Removals (1997) 22
Tree and Log Grades 22
Metric Equivalents 28
Tree Species Groups in Illinois 28
Definition ofTerms 29
Literature Cited 37
Table Titles 38
Tables 42
Illinois' Forests in 1998
Thomas L. Schmidt, Mark H. Hansen, and James A. Solomakos
Illinois has avariety offorest resources that EXTENT OF ILLINOIS* FORESTS
make significant environmental and economic
contributions. In addition to employment and • Area offorest land and timberland has
other economic contributions, Illinois' forests increased since the 1960's (timberland is a
provide outdoor recreation experiences as well subset offorest land; timberland has mini-
mum
as improve and protect the State's soil and productivity capabilities and is not
water resources. The State is divided into permanently excluded from harvest by
three Survey Units, based largely on topogra- legislation or administrative order). Due to
phy and location offorest land (fig. 1). the dominance oftimberland, the majority
ofthis report presents results related to
HIGHLIGHTS timberland. Timberland has historically
represented more than 90 percent ofthe
total area offorest land in Illinois. For
• The area ofIllinois' forests continued to
example, ofthe 4.3 million acres offorest
show a net increase between inventories, a
land in 1998, 94 percent was classified as
trend that began in the 1960's. The pri-
timberland.
mary causes were increases in the width of
existing narrowwooded strips and the
• The area oftimberland in Illinois has been
conversion ofcropland and pasture to forest
steadily increasing since the 1960's. Tim-
land. These increases were greater than
berland increased from 3.981 million acres
losses by development offorest land for
in 1962, to 4.030 million acres in 1985, to
agriculture, urban/suburban expansion,
and other uses. 4.087 million acres in 1998 (fig. 2). In
1998, timberland represented 11 percent of
the total land area in Illinois.
• Net growth exceeded harvest in Illinois.
Average annual net growth ofgrowing stock
• The majority ofthe increase in area of
exceeded the average annual harvest by a
timberland between 1985 and 1998 oc-
2.6 to 1 margin between 1985 and 1997. curred in the Southern Unit. The Claypan
As a result ofthe expanding resource and
Unit slightly increased while the Prairie Unit
the greater growth than harvesting, the
slightly decreased in area oftimberland.
volume oftrees growing in Illinois continued
to increase.
• Pope County, in the Southern Unit, was the
most heavily forested county in both 1985
• During the 13 years between inventories,
(143 thousand acres oftimberland) and in
an average of21.8 million new growing-
1998 (151 thousand acres oftimberland).
stock treeswere established each year in
Illinois. As a result, in 1998 there were
• In 1998, the Southern Unitwas the most
283.7 million more growing-stock trees than
heavily forested Survey Unitwith almost 3
in 1985.
out ofevery 10 acres classified as timber-
land. Conversely, in the Prairie Unit, less
• The future ofthe forest lies in the hands of
individual private landowners. They own than 1 out ofevery 10 acres was classified
as timberland. The Prairie Unit was the
almost 90 percent ofthe total area oftim-
most urbanized and agriculturally oriented
berland in Illinois.
part ofthe State. In the Claypan Uinit, 15
percent ofthe total area ofland was classi-
Thomas L. Schmidt and Mark H. Hansen fied as timberland.
are Research Foresters, and James A.
Solomakos is a Computer Programmer • Individual private landowners were the
Analyst, in the Forest Inventory and Analysis largest timberland ownership group in
Program at the North Central Research Illinois, owning 82 percent ofall timberland
Station, St. Paul, Minnesota. in 1998. The Federal government was the
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