| Wetland quality and developmental trajectory of palustrine emergent wetlands in Northeastern Illinois were studied. In the first phase of the research, a flexible and adaptable index of wetland quality based upon recognized wetland functions was developed. During the second phase a small set of landscape features was used to predict the quality of wetlands. The objective of the research is to develop a tool for planners, resource managers, and ecological engineers to use in siting and designing mitigation, and evaluating the affects of land use decisions on existing wetlands.;Field data and historical photography from twenty-one wetlands in Northeastern Illinois with varying degrees of disturbance were studied using a wetland quality index derived from metrics used to measure floristic quality and wildlife habitat quality. The quality index can be extended to include measures of other wetland functions and can be weighted to reflect local regional, and national values associated with the functions.;Twenty-nine landscape features were evaluated and a subset of features was selected that can be used to predict the trajectory of wetland quality. Three features representing system age, the ratio of watershed area to wetland area, and the average hydrologic condition of the watershed were used to develop a mathematical relationship with the wetland quality index.;The relationship is based on familiar procedures and uses features that may be obtained from existing data banks. The approach can be adapted for use with geographic information systems and is compatible with the proposed hydrogeomorphic classification system for wetlands. |
