Modern Vegetation of the Chicago Region


Chicago region vegetation is organized across a soil moisture gradient, and is thought to have been originally patterned by landscape-scale fire. Our work with natural remnants asks: how plant species are distributed across the Chicago region along environmental gradients? How do they assemble into different communities that can be identified and maintained in their natural state? and how is this vegetation changing over time, especially in response to fire exclusion? These questions have very practical ramifications for understanding,managing and restoring native vegetation.


Much of our work is based on analysis of a large data set established in 1976 by the Illinois Natural Areas Inventory for Chicago region prairies (N = 72 ), wetlands (N = 31 ) and forests (N = 28), which we resampled in 1996 (forests), 2001 (prairies) and 2002 (wetlands). Analyses of these data have provided a regional model and data base of species and community distribution along substrate and moisture gradients, and have illustrated significant temporal changes linked with fire-protection and fire management. These data also provide a framework for community restoration. We have also conducted more detailed gradient analyses on effects of drainage and canopy cover on savanna vegetation and substrate chemistry on fen vegetation.

We also maintain a collection of 600 tree cores from Chicago region old-growth forests. Tree ring analyses provide a linkage between historic and modern vegetation, and clarify how these forests had changed over time.

Selected References

Bowles, M, M. Jones, J. McBride, T. Bell, & C. Dunn. 2000. Structural composition and species richness indices for upland forests of the Chicago region. Erigenia (18)30-57. pdf

Bowles, M., M. Jones, J. McBride, T. Bell & C. Dunn. 2005. Temporal instability in Chicago’s upland old growth forests. Chicago Wilderness Journal 3(2)5-16.  pdf

Bowles, M.L., J.L. McBride, N. Stoynoff, & K. Johnson. 1996. Temporal change in vegetation structure in a fire-managed prairie fen. Natural Areas Journal 16:275-208.  pdf

Bowles, M. & M. Jones. 2004. Long term changes in Chicago region prairie vegetation in relation to fire management. Chicago Wilderness Journal 2(2)7-16.  pdf

Bowles, M. & M. Jones 2006. Trends of change in composition and structure of Chicago region wetland vegetation. Chicago Wilderness Journal 4(3)25-34.  pdf

Bowles, M.L., P.D. Kelsey & J.L. McBride. 2005. Relationships among environmental factors, vegetation zones, and species richness in a North American calcareous prairie fen. Wetlands 25(3):685-697. pdf

Bowles, M. & M. Jones. 2006. Testing the efficacy of species richness and floristic quality assessment of quality, temporal change and fire effects in tallgrass prairie natural areas. Natural Areas Journal 26:17-30. pdf

Bowles, M. & M. Jones. 2006. The prairie-wetland vegetation continuum in the Chicago region of northeastern Illinois. Pages 23-35 in: Proceedings of the 19th North American Prairie Conference. D. Eagan & J. Harrington (eds). Madison, Wisconsin.  pdf

Bowles, M. & M. Jones. 2007. The prairie-wetland vegetation continuum in the Chicago region of northeastern Illinois. Ecological Restoration 25 (1):29-38.  pdf

Bowles, M.L., and J. L. McBride. 1998. Vegetation, composition, structure, and chronological change in a decadent Midwestern North American savanna remnant. Natural Areas Journal, 18, 14-27. pdf

Anderson, R.C. & M.L. Bowles 1999. Deep-soil savannas and barrens of the midwestern United States. pages 155-170 in, R.C. Anderson, J. Fralish, & Jerry Baskin (editors), The savanna, barren, and rock outcrop communities of North America. Cambridge University Press. pdf

Haney, A. M. Bowles, S. Apfelbaum & E. Lain. 2008. Gradient analysis of an eastern sand savanna’s woody vegetation, and its long-term responses to restored fire processes. Forest Ecology and Management(266)1560-1571. pdf