Pre-European Settlement Vegetation of Kendall County, Illinois
DescriptionReport to the Kendall County Forest Preserve District, Chicago Wilderness, USDA Forest Service, US Fish & Wildlife Service, and the Illinois Conservation Foundation.
AbstractWe mapped and analyzed the landscape pattern and composition of vegetation described by the U. S. Public Land Survey (PLS) of Kendall County, Illinois, which was conducted between 1821 and 1838. Kendall County was mapped by the PLS as 85 % prairie, 12 % timber, 2 % scattering timber and less than 1 % barrens and brush. Timber was primarily restricted to fire-protected borders of the Fox River and its tributaries, and in isolated groves in the southwestern and southeastern parts of the county. Scattering timber occurred in association with timber along the Fox River, Blackberry Creek and Rock Creek. Based on calculations from bearing tree densities, areas mapped by the PLS as timber were about 60 % savanna, averaged 80 trees/ha, and were dominated by bur, white and black. Areas of scattering timber were about 70 % savanna, averaged less than 40 trees/ha, and were dominated by bur oak. Black oak was an important secondary species in both types. Forest and woodland, represented by > 100 trees/ha and 50-100 trees/ha, respectively, represented about 40 % of the areas mapped as timber and 30 % of the areas mapped as scattering timber. They were also dominated by white oak, but had less abundance of bur oak and greater abundance of the mesophytic species red oak, sugar maple, basswood and ash. The landscape pattern of this vegetation indicates that fire processes played a significant role in shaping the presettlement vegetation pattern of Kendall Co. Fire is therefore critical for restoring and managing woody vegetation to represent presettlement conditions, as well as for maintaining the floristic diversity present at the time of settlement.