LAND-USE HISTORY AND RESULTING FOREST
SUCCESSION IN THE ILLINOIS OZARK HILLS
Saskia L. van de Gevel and Charles M. Ruffner1
Abstract—A historical ecology project was designed to quantify the influence of different land
uses on forest development in the Ozark Hills of southern Illinois. By incorporating land-use
history research, dendrochronology, and stand structure analysis, disturbances such as selective
cutting, burning, grazing, and agricultural clearing have been investigated to determine their
long-term effects. After the settlement of Union County in the 1830s, much of the landscape
has been manipulated by humans via logging, grazing, agricultural clearing, and fire exclusion.
Selective logging of upland sites removed some pre-settlement trees, yet most of these sites
retained their forest structure. Bottomland sites were mostly cleared for subsistence agriculture
by the 1860s then abandoned around 1925, allowing for recruitment of mesophytic species. With
state management in the 1930s came a fire suppression program, which ultimately fostered the
expansion of sugar maple (Acer saccharum M.) and American beech (Fagus grandifolia Ehrh.)
onto rich upland loess soils. This alteration of the disturbance regime is currently causing a
transition from the presettlement oak-hickory forest type to a later successional sugar maple-beech
forest type.
INTRODUCTION
Land-use history has been used to analyze the change from pre-European to present forest conditions
(Foster and others 1996, Ruffner and Abrams 1998). The historical context provided by land-use
studies reveals a long-term pattern of change that challenges assumptions about the pristine conditions
of presettlement forests (Foster and others 1996). Investigations of land-use history and vegetation
change provide a background for understanding the development of the modern vegetation landscape
(Christensen 1989).
Across the Central Hardwoods Region, old-growth forests appear to be in transition from oak-hickory
dominated species to shade tolerant species. The decline of these forests is attributed to a combination
of climatic change and the removal of anthropogenic and natural disturbances (Parker 1989). The
Illinois Ozark Hills have been studied with relation to changes between presettlement and current forest
communities (Leitner 1981, Weaver and Ashby 1971). In the presettlement community, white oak
(Quercus alba L.) was the leading dominant while sugar maple was consistently low in importance. Sugar
maple has dramatically increased in importance over the past 160 years (Leitner and Jackson 1981).
Weaver and Ashby (1971) related this increase to a lack of major disturbance in the last century, increased
precipitation, and selective cutting.
Our objectives were to (1) Research the land-use history, documented in land ownership tax records, and
local and historical documents, (2) Understand land-use variation across different topographic gradients,
and (3) Characterize the current stand composition and structure.
STUDY AREA
Braun (1950) classifies the vegetation of the Illinois Ozark Hills as Western Mesophytic, while Küchler
(1964) includes it in the Oak-Hickory region. The study area within Trail of Tears State Forest (TTSF) was
chosen because it was adjacent to agricultural land and had a relatively low percent slope (0-50 percent)
compared to other parts of TTSF, where slopes are as steep as 80 percent.
1
Saskia L. van de Gevel, Ph.D. Candidate, Department of Geography, Knoxville, TN 37996; and Charles M. Ruffner, Associate
Professor, Southern Illinois University, Department of Forestry, Carbondale, IL 62901.
Proceedings of the 15th Central Hardwood Forest Conference
e-GTR–SRS–101
719
Mild winters and hot summers characterize the climate of southern Illinois. The mean January
temperature is 2°C while the mean July temperature is 26°C. The average number of frost-free days
is 206, extending between April and October. Approximately 50 percent of the 116.8 cm of annual
precipitation falls from April to September. The growing season averages 230 days (Miles 1978).
METHODS
In the summer of 2001, a 117 ha area in the eastern section of TTSF was sampled for present forest
structure and disturbance history. Sixty 0.04 ha rectangular (40 m x 10 m) plots were proportionally
allocated across the ridgetop (greater than 183 m elevation, n = 14), midslope (165-183 m elevation, n =
27), and riparian (less than 165 m elevation, n = 19) forest sites. Site characteristics recorded at each plot
included percent slope and slope position, which was assigned as ridgetop (1), midslope (2), and riparian
(3).
Overstory vegetation was sampled within each 0.04 ha rectangular plot. All trees greater than 5.0 cm
at diameter breast height (dbh: 1.47 m) were recorded by species. Tree crowns were classified into four
categories (dominant, co-dominant, intermediate, and suppressed) based on the amount and direction of
intercepted sunlight (Smith 1986). All saplings less than 5.0 cm but greater than 1.0 cm in diameter at
ground level (dgl) were tallied every 10 m within a 0.025 ha (L = 5 m) nested rectangular plot. Seedlings
less than 1.0 cm dgl were measured within a 0.0025 ha (L = 1.58 m) nested rectangular plot in the sapling
plot every 10 m.
In each overstory plot, 4-8 trees were selectively cored for age determination using a sharpened increment
borer. After sanding the 315 collected tree cores, cores were initially dated and then visually crossdated
using the signature year technique (Yamaguchi 1991). Historical data of TTSF was collected from local
land deed and tax records, from Union County historians, and from past Illinois Natural History Surveys.
RESULTS AND DISCUSSION
Land-Use History
The influence of Native American hunting grounds, railroads, sawmill towns, and the Civilian
Conservation Corps (CCC) on forest development reflects an interesting history of land-use in the
Ozark Hills through pre and post-European periods (table 1). Historic inhabitants, like the Shawnee
and Kaskaskia Indians, either passed through TTSF on their way to other areas or used the region on an
ephemeral, task specific basis (Hassen and Schroeder 1987). Although this region of southern Illinois
appears to have been largely uninhabited by Native Americans after 1450 AD, several groups passed
through this region throughout the 17th and 18th centuries. While their influence on the landscape is not
quantified, the prevalence of disturbance-oriented vegetation across this region at settlement suggests a
high incidence of burning from either natural (low incidence of lightning caused fires in the Midwest)
or human ignitions (Parker and Ruffner 2004). The land survey records of 1806-1807 suggest fire was
common in the forests of southern Illinois mentioning prairies, barrens, glades, open woodlands, and
burnt trees (Fralish 1997). European settlers began coming into the area at a steady pace after the War of
1812. The region was known for excellent hunting grounds, and the proximity of the Ohio and Mississippi
Rivers offered additional transportation and commercial advantages to the area.
Approximately 13,000 Cherokee were forced to travel on an overland route in October 1838, and arrived
in Union County in the winter of 1838-39. Approximately three miles south of TTSF, the Cherokee
were forced to camp as they waited for the ice of the Mississippi River to melt so they could cross over
to Missouri and complete their journey (Norton and Anderson 1989). We suggest these Cherokee were
collecting firewood for cooking and heating and numerous accounts admit to widespread hunting and
foraging to augment the meager rations of the US Army (Parker and Ruffner 2004).
The Illinois Central Railroad was given land by the Land Grant Act of 1850, to sell to European settlers as
a source of revenue, and to cut railroad ties so railroad expansion could continue across the Midwest. In
the 1881 Atlas of Union County (Griffing 1881), the study area in TTSF was solely owned by the Illinois
720
Proceedings of the 15th Central Hardwood Forest Conference
e-GTR–SRS–101
Table 1—Major land uses affecting Trail of Tears State Forest and resulting forest development
Date
Land use practice
Forest impact
Native American hunting grounds
European-American settlement
New Madrid earthquakes
Grazing of domestic livestock
Trail of Tears-exiled Cherokee
Indians
Sawmill towns
Railroads
Ice storm
Purchased by the Department of
Conservation
Hunting pressure and understory burning
Timber cut to build homes, roads, and towns
Downed timber and oak regeneration
Soil compaction and understory damage
Cherokee hunted and made make-shift camps
1934–1937
Civilian Conservation Corps
Fire trails on ridgetops, pine planted, and tree
nursery
1938
6WDWHLQDXJXUDWHG¿UHSURWHFWLRQ
program
6XSSUHVVLRQRIIRUHVW¿UHVWKDWZHUH
historically common on the landscape
Before 1800
After 1803
1811–1812
1830–1930
1838–1839
1840–1930
1850–1880
1913
1929
Timber cut for barrels and lumber industry
Timber cut for railroad ties and routes
Trees damaged
Much of TTSF has been selectively logged
TTSF = Trail of Tears State Forest.
Central Railroad. Although Union County was established in 1818, European settlers did not start buying
land from the railroads in the study area until 1899. This does not suggest that land was not managed
before 1899, but does explain why there are no tax records showing timber harvesting occurring before
that time.
The earliest settlers had discovered that the terrain and climate of Union County were conducive for the
production of fruit trees in the Ozark Hills, and the new railroad provided fast shipment of produce to
Chicago markets (Mohlenbrock 1974). For income in the 1890s, people worked in timber production
during the winter to cut railroad ties for fifty cents per day (Adams 1994). Most of the old-growth forests
on the uplands of Union County were harvested in the 1890s (Adams 1994).
Between 1870 and 1940, southern Illinois was at its height of lumber and wood production. During that
period, the region held a national role in timber production (Mohlenbrock 1974). Timber was cut for the
manufacture of crates, barrels, and baskets for shipment of locally grown produce to markets, in addition
to selective harvesting for building supplies, railroads, and roads (Mohlenbrock 1974). Timber prices
were highest during the 1920s, supporting at one time as many as thirty-two sawmills in Union County.
These tree-ring and land-use data supports and strengthens Fralish’s (1997) previous work comparing
presettlement forests and increased oak importance in the present forest overstory. The increase in oak
is consistent with higher levels of disturbance associated with postsettlement timber harvesting, fire, and
grazing that occurred in the 1920s and 1930s (Fralish 1997). Fire frequency decreased considerably in the
last 60 years in xeric oak-hickory communities in southern Illinois, due largely to fire suppression efforts
by local, state, and federal agencies (Robertson 1994).
Current Vegetation
Repeated sampling of permanent plots in east-central Illinois and in southern Illinois (Ozier 2001) has
established that the importance of oak species have declined and that sugar maple has increased over the
past five decades. The increased presence and importance of mesophytic species along the topographic
gradient indicates a transition from disturbance-oriented species to more shade tolerant species. Oak
Proceedings of the 15th Central Hardwood Forest Conference
e-GTR–SRS–101
721
seedlings are common in these stands, but larger saplings and subcanopy trees are absent, suggesting that
the absence of large-scale disturbances on these sites since the 1930s has contributed to the failure of
oak to recruit into the canopy (fig. 1). In general, oaks are being successionally replaced by other species,
despite observations that many forests contain a substantial number of oak seedlings (Abrams 1992).
This transition will result in reduced mast, wildlife habitat, and species diversity. The future forest, if
current trends continue, will be dominated by sugar maple (Shotola and others 1992). Based on a stand
table projection analysis in the Illinois Ozark Hills, Helmig (1997) found that the south slope, ridgetop
and north slope site types will support a forest of sugar maple, American beech, and other mesophytes
in approximately 50 years. In addition to anthropogenic disturbances over the past 300 years, a natural
landscape-level disturbance occurred as well. The New Madrid earthquakes of 1811-1812 caused a large
amount of downed timber in southern Illinois (Jones 2003), and a hurricane shortly after the earthquake
would have caused additional damage (Shotola and others 1992). Dates for red oak (Q. rubra L.)
establishment (from 1816 to 1841) suggest that much of the oak regeneration occurred during the period
of the New Madrid earthquake and hurricane disturbance. White oak recruitment was also initiated on the
ridges after the earthquakes in 1811 and 1812 (fig. 2).
An icestorm in 1913 fostered tree recruitment on bottom sites (fig. 2). Glaze damage to trees occurs when
ice adds excessive weight to leaves and branches (Warrillow and Mou 1999). Most icestorm damage
involves large branch breakage without the loss of the whole tree, thus creating scattered canopy openings
of varying size, rather than the larger contiguous openings characteristic of wind blowdowns (De Steven
and others 1991, Runkle 1985). Warrillow and Mou (1999) found that susceptibility of canopy trees to
ice damage is determined not only by species characteristics, but also by site conditions, like aspect and
landform. The icestorm in 1913 caused recruitment of tulip-poplar (Liriodendron tulipifera L.), hickory
(Carya sp.), white oak, and sweetgum (Nyssa sylvatica Marsh.). The trees on the bottoms in 1913 would
have been only 25 years old (grazing kept bottoms open until 1890s), so a major icestorm would have
killed many of these young trees. The trees that were recruited in 1913 now make up the dominantintermediate canopy classes on the bottom sites.
In the 1930s, white oak and sugar maple recruitment were initiated after the Civilian Conservation
Corps (CCC) cut the ridgelines to build firetrails. Recruitment followed human disturbance patterns,
while many species benefitted from these cuttings, sugar maple recruitment was further enhanced by
suppression of fires by the CCC. The overall increase of mesophytic species on the ridgetop and midslope
sites after 1940, reflects a reduced disturbance frequency (fig. 2). It is important to note that with the
state inaugurated fire protection program in the 1930s came a large cohort of sugar maple recruitment
across ridge, midslope, and bottom sites. Without canopy disturbances increasing the amount of sunlight,
oak reproduction generally fails, allowing more shade tolerant species, in the absence of fire, to become
established in the understory and slowly replace dominant oaks in the overstory (Brose and Van Lear
1998).
Currently no cutting is taking place at TTSF, but prescribed fire is being used in an attempt to suppress
the invasion of mesophytic species. The artificial suppression of natural disturbances, particularly
fire, ultimately eliminated disturbance-dependent species (Fralish 1997). Brose and Van Lear (1998)
demonstrated that fire treatments reduce densities of all hardwood species relative to not burning, with
spring and summer fires causing the greatest density reduction. They also noted that prescribed fires
improved oak advance regeneration with spring burning providing the most benefit.
722
Proceedings of the 15th Central Hardwood Forest Conference
e-GTR–SRS–101
Figure 1—Canopy class distributions across topographic positions. Quru= Quercus rubra,
Quve= Quercus velutina, Qual= Quercus alba, Qust= Quercus stellata, Carya= Carya species,
Litu= Liriodendron tulipifera, List= Liquidambar styraciflua, Mesophytes= Acer saccharum, Fagus
grandifolia, Others= Sassafras albidum, Ostrya virginiana, Fraxinus americana, Fraxinus pennsylvanica.
Proceedings of the 15th Central Hardwood Forest Conference
e-GTR–SRS–101
723
Acsa
Carya spp.
Qual
Quru
Qust
Quve
Ridgetop
Acsa
Carya spp. Fram
Litu
Quru
Qual
Quve
Midslope
Acsa
Carya spp.
Fagr Frpe
List
Litu Qual Quru
Bottom
Figure 2—Age-diameter relationship for all cored trees on ridgetop, midslope,
and bottom sites. (Species labels in fig. 1.)
CONCLUSION
Land-use practices on TTSF included the use of hunting, fuelwood collecting, and burning by Native
Americans to drive game. European settlers then cut forests to develop farms, agricultural clearing,
railroads, and sawmill towns from 1850-1930, followed by fire suppression and trail building by the
CCC in the 1930s. The New Madrid earthquake in 1811, a localized icestorm in 1913, periodic fire,
and drought characterized the natural disturbance regime. Site susceptibility to these disturbances was
controlled by the rugged terrain, and slope position. The results of this historical ecology project support
previous interpretations, drawn from witness tree data and permanent plot inventories, that disturbance
processes have been important in this region over the past 300 years.
Along the ridge and midslope sites, the uneven-aged stands were dominated by oak and hickory, while
smaller diameter classes consisted of sugar maple and American beech. The bottom sites were dominated
724
Proceedings of the 15th Central Hardwood Forest Conference
e-GTR–SRS–101
by tulip-poplar, but are also being replaced by sugar maple and American beech, due to the continued
absence of disturbance. Further research should be conducted on a combination of shelterwood harvests
and prescribed fire, to regenerate oak and hickory species on xeric and mesic sites.
LITERATURE CITED
Abrams, M.D. 1992. Fire and the development of oak forests. Bioscience 42: 346-353.
Adams, J. 1994. The transformation of rural life, southern Illinois, 1890-1990. The University of North Carolina Press.
Braun, E.L. 1950. Deciduous forests of Eastern United States. Blakiston Company, New York. 189 p.
Brose, P.H.; Van Lear, D.H. 1998. Responses of hardwood advance regeneration to seasonal prescribed fires in oak-dominated
shelterwood stands. Canadian Journal of Forest Research 28: 331-339.
Christensen, N.L. 1989. Landscape history and ecological change. Journal of Forest History 86: 116-124.
De Steven, D.; Kline, J.; Matthiae, P.E. 1991. Long-term changes in a Wisconsin Fagus-Acer forest in relation to glaze storm
disturbance. Journal of Vegetation Science 2: 201-208.
Foster, D.R.; Orwig, D.A.; McLachlan, J.S. 1996. Ecological and conservation insights from reconstructive studies of temperate
old-growth forests. Trees 11: 419-424.
Fralish, J.S. 1997. Community succession, diversity, and disturbance in the central hardwood forest. In Conservation in highly
fragmented landscapes. Chapman and Hall, New York. 448 p.
Griffing, B.N. 1881. Atlas of Union County, Illinois. D.J. Lake and Company. Philadelphia, PA.
Hassen, H.; Schroeder, M.B. 1987. Cultural resource studies at Illinois Department of Conservation State Parks and Recreation
Areas. Volume One: The 1985 season. Document number 2287, Illinois State Museum Society.
Jones, M.E. 2003. Successional dynamics and dendroecology of Pinus echinata (Mill.)-mixed Quercus forests at LaRue-Pine
Hills, southern Illinois. M.S. Thesis, Department of Forestry, Southern Illinois University. 97 p.
Küchler, A.W. 1964. Potential natural vegetation. U.S. Geological Survey Sheet No. 90.
Leitner, L.A.; Jackson, M.T. 1981. Presettlement forest of the unglaciated portion of southern Illinois. American Midland
Naturalist 105: 290-304.
Marcucci, D.J. 2000. Landscape history as a planning tool. Landscape Urban Planning 49: 67-81.
Miles, C.C. 1978. Soil survey of Union County, Illinois. USDA Soil Conservation Service, in cooperation with Illinois
Agricultural Experimental Station. 143 p.
Mohlenbrock, R.H. 1974. A new geography of Illinois, Union County. Outdoor Illinois, June-July.
Norton, L.J.; Anderson, T.L. 1989. The history of Alto Pass, Illinois. Thomas L. Anderson. Dallas, Texas. 142 p.
Ozier, T. 2001. Forest stand dynamics at Trail of Tears State Forest: 1980-2000. M.S. Thesis, Department of Forestry, Southern
Illinois University, Carbondale. 176 p.
Parker, G.R. 1989. Old-growth forests of the central hardwood region. Natural Areas Journal 9: 5-11.
Parker, G.R.; Ruffner, C.M. 2004. Current and historical forest conditions and disturbance regimes in the Hoosier/Shawnee
ecological assessment area. In: Hoosier/Shawnee Ecological Assessment, F.R. Thompson III (eds). Gen. Tech. Rep. NC-244.
U.S. Department of Agriculture, Forest Service, North Central Research Station: 23-58.
Robertson, P.A.; Heikens, A.L. 1994. Fire frequency in oak-hickory forests of southern Illinois. Castanea 59: 286-291.
Ruffner, C.M.; Abrams, M.D. 1998. Relating land-use history and climate to the dendroecology of a 326-year-old Quercus prinus
talus slope forest. Canadian Journal of Forest Research 28: 347-358.
Runkle, J.R. 1985. Disturbance regimes in temperate forests. In: S.T.A. Pickett, P.S. White (eds). The ecology of natural
disturbance and patch dynamics. Academy Press, Orlando. 472 p.
Proceedings of the 15th Central Hardwood Forest Conference
e-GTR–SRS–101
725
Shotola, S.J.; Weaver, G.T.; Robertson, P.A.; Ashby, W.C. 1992. Sugar maple invasion of an old-growth oak-hickory forest in
southwestern Illinois. American Midland Naturalist 127: 125-138.
Smith, D.M. 1986. The practice of silviculture. John Wiley & Son’s. New York.
Suchecki, P.F. 1999. Vegetation analysis and succession at LaRue-Pine Hills/Otter Pond Research Natural Area, Union County,
Illinois. M.S. Thesis, Department of Plant Biology, Southern Illinois University, Carbondale.
Warrillow, M.; Mou, P. 1999. Ice storm damage to forest tree species in the ridge and valley region of southwestern Virginia.
Journal of the Torrey Botanical Society 126: 147-158.
Weaver, G.T.; Ashby, W.C. 1971. Composition of an old-growth forest remnant in unglaciated southwestern Illinois. American
Midland Naturalist 86: 46-56.
Yamaguchi, D.K. 1991. A simple method for cross-dating increment cores from living trees. Canadian Journal of Forest Research
21: 414-416.
726
Proceedings of the 15th Central Hardwood Forest Conference
e-GTR–SRS–101