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Our findings closely parallel those of Swink and Wilhelm (1994) despite the geographic and climatic differences between the prairie pothole region and the Chicago region. Swink and Wilhelm found that values for restored wetlands in the Chicago region tended to reach maximums between 3.0 and 3.7 after approximately five years, with FQIs ranging from 25 to 35. Restored wetlands within the wetland complexes we studied had values ranging from 2.1 to 3.8, with the highest values occurring in wetlands of the oldest complex (Hawk's Nest). Wetlands at the natural complex, Cottonwood Lake, had the highest values (3.4 to 4.7) of any of the four complexes studied. Floristic quality index values for the restored wetlands in our study were generally lower than those found for restored wetlands by Swink and Wilhelm (1994); however, they followed the same trend, with FQI values increasing as wetlands increased in age and peaking at about 21 in the oldest restored complex we evaluated.

Species richness may provide a distorted picture of the floristic quality of specific sites. Several of our restored wetlands had species richness values meeting or exceeding values for wetlands at Cottonwood Lake. Based on richness alone, it would be easy to conclude that the restored wetlands had floristic quality equal to or exceeding that of the natural wetlands at Cottonwood Lake. However, by applying C values and calculating and FQI values for each wetland, we found that although species richness was similar among wetlands, many of the species present in restored wetlands were relatively low quality, “opportunistic” species, and as expected, the natural area had the greatest floristic quality with more conservative species than any of the three restored complexes we examined. Additionally, 95% confidence limits overlapped greatly among complexes when considering species richness (Table 6). However, confidence limits for both and FQI overlapped little among the natural and restored complexes (Tables 4 and 5), clearly showing that Cottonwood Lake supported plant communities of greater floristic quality than any of the restored complexes. A trend in increasing floristic quality as restored wetlands age is also clearly evident in the and FQI values. This trend is suggested but obscured in the species richness values due to overlapping confidence limits among all three restored complexes.

The historic land-use and current management strategies at Cottonwood Lake have not been optimal to promote the preservation of conservative species. Only three species at Cottonwood Lake had a panel-assigned C value of 10 (Table 1). Although none of the wetlands at Cottonwood Lake have been drained, approximately 18% of the upland areas surrounding the wetlands had been tilled and planted to agricultural crops prior to acquisition by the U.S. Fish and Wildlife Service in 1963. This disturbance of the uplands and the resulting alteration of the wetlands through sediment and chemical inputs (Martin and Hartman 1986, Grue et al. 1989, Gleason and Euliss 1998) may have adversely affected some conservative species. Since 1963, management of the site by the U.S. Fish and Wildlife Service has been directed by long-term studies of wetland hydrology, water chemistry, and wetland biota. These studies have limited the extent to which fire, grazing, and other management tools could be used to promote the preservation of conservative species that evolved under natural regimes of periodic burning and grazing. Even given the less than optimal conditions at Cottonwood Lake, its wetlands still had greater floristic quality (i.e., supported more conservative species) than wetlands of the restored complexes we evaluated. In fact, there were 15 species with panel-assigned C values greater than 5 that occurred at Cottonwood Lake but did not occur in any of the 3 restored complexes (Table 1).

values of restored wetlands in the complexes we studied rarely exceeded 3.4 and usually reached maximums closer to 3.3 in the oldest restored complex; respective FQI values rarely exceeded 22 and usually reached maximums closer to 19. Not a single species with a panel-assigned C value of 10 occurred in any of the restored complexes. Additionally, we found that wetlands with values greater than 3.8 or FQI values greater than 25 had plant communities of a quality that was not duplicated in any of the restored complexes we studied. The floristic quality assessment method developed and refined by Swink and Wilhelm (1979, 1994) provides a means by which these high quality wetlands can be identified. In addition to evaluating restoration efforts and identifying areas of high floristic quality, floristic quality assessment can be used to facilitate comparisons of plant communities among different sites, to monitor areas for changes in floristic quality over time, and to evaluate the response of plant communities to management treatments.

The rules we used to derive data-generated C values (Table 3) for plant species data collected by Gleason and Euliss (unpublished data) produced greater C values with a different distribution than those subjectively assigned by the Northern Great Plains Floristic Quality Assessment Panel (Table 1). The five disturbance classes we chose may not have adequately spanned the entire disturbance gradient. Four of the five classes had tilled soils surrounding the wetlands. Thus, a plant occurring in a natural wetland that had the uplands tilled and replanted to grasses could have received a coefficient as high as a 9. Using the criteria established by the panel (Northern Great Plains Floristic Quality Assessment Panel 2001) the same species would likely receive a C value of 4 or less. Using the panel's criteria, coefficients of 5 or more were reserved for species that almost always occur in natural areas but with varying degrees of degredation; we only had a single class for native prairie wetlands and gave all plants that only occurred there the maximum C value of 10. Even though the s and FQIs we obtained using the C values generated from data were consistently greater than those obtained using the coefficients assigned subjectively, the conclusions reached based on the independent evaluations were virtually identical. The similarity of the two evaluations supports the argument that C values assigned subjectively by expert botanists familiar with a region's flora provide adequate information to perform accurate floristic quality assessments.