Ecological Implications of Urban and Community Tree Care in Illinois

Tree City USA (TCU) has worked with communities across the United States to enhance their urban 99forests, thereby providing oxygen, air conditioning, pollution and temperature reduction, wind breaks, and habitat for urban wildlife. It is well known that the endeavors of TCU have increased the aesthetics and health of urban centers in Illinois as well as across the nation. However, no one has quantitatively measured the ecological significance of this program and benefits of TCU status at a state-wide scale. This project considered tree land cover, stream water quality, bird species diversity, and the fish index of biotic integrity(IBI) across communities in correlation with Tree City USA status and level of tree care in communities based on the United States Department of Agriculture Forest Service’s annual state reporting system, the Community Accomplishments Reporting System (CARS).Illinois is comprised of varying topographic, geographic, and sociologic regions ranging from bluffs, to extensive farm land, to major urban centers. To address this regional variation the state was divided into three regions: Northeastern, Central, and Southern Illinois based on county boundaries. We found significantly more bird species observations during spring and fall migration Tree City communities compared to non-Tree City communities. Communities with sustaining tree care programs (as assessed by CARS) had significantly more birds species observed than communities with no tree care or developing tree care programs, especially in the spring and fall. Tree canopy cover, stream water quality parameters, and fish IBI did not correlate with Tree City communities, indicating that the benefits of the TCU program to these ecosystems may be at a more local scale. These preliminary analyses suggest the opportunity and need for further and more localized or smaller-scale research.