A REEXAMINATION OF RESTORED WETLANDS IN MANITOWOC COUNTY, WISCONSIN
Thomas S. Nedland
The United States Fish and Wildlife Service (USFWS) has restored hundreds of wetlands in Manitowoc County, WI since the late 1980’s. The primary purpose of these restorations was to enhance the capability of the landscape to support waterfowl and other wetland associated species.
In 1992, the waterfowl, invertebrate, anuran, and plant communities at some of these restorations were examined. I re-examined eighteen of these wetlands during the summer of 2004 to determine how the waterfowl, anuran, and plant communities at these sites have changed over time. I also examined the waterfowl, anuran, and plant communities at 8 natural wetlands found in Manitowoc County to determine if differences existed between the natural and restored communities.
Significant differences between the 1992 and 2004 restored plant communities were found, suggesting that the restorations are still developing. Significant differences were also found between the natural and restored wetland plant communities, suggesting that the restorations may not develop into habitats representative of the natural wetlands found in the area.
No significant differences in anuran abundance were found between the two time periods, but significant differences in anuran abundance were found between the natural and restored wetlands. These differences are most likely related to the differing hydroperiods that exist between the natural and restored communities.
Significant differences were not detected in the waterfowl communities over time, but the data suggests that more waterfowl used the restorations in 2004 than in 1992. There were also no significant differences between the waterfowl communities of the restored and natural wetlands; however, the restorations were used more frequently by waterfowl than the natural wetlands.
Although successful at creating habitat for waterfowl and other wetland dependent species, it does not appear an effort was made to mimic the hydrologic regime of local, natural wetlands. The restorations appear to have longer hydroperiods than the natural wetlands, which most likely explains the majority of differences between the waterfowl, anuran, and plant communities of the two wetland types.