Floristic and Macroinvertebrate Responses to Different Wetland Restoration Techniques in Southeastern Wisconsin

Abstract

Assessments of wetland restoration quality, especially comparisons among restoration techniques, are essential to adaptive management, but are rarely reported. We evaluated wetlands in southeastern Wisconsin that were restored using different hydrological techniques along with wetlands in two reference groups: wetlands without hydrological modification and Waterfowl Production Areas. Our objectives were 1) to compare condition of wetlands using indices for plant communities and macroinvertebrates and 2) evaluate provisioning of macroinvertebrates for waterfowl broods as a measure of habitat quality. Overall, floristic quality of sedge meadows and emergent marshes was poor in restored wetlands (weighted mean C-values were 1.55 ± 0.13 (SE) and 1.47 ± 0.25, respectively); however, sedge meadow quality was greater in wetlands without surface modification (weighted mean C-value = 3.43 ± 0.82). On a scale from “excellent” to “very poor”, we classified condition of open water communities as “good” based on the macroinvertebrate index across all restoration categories. Density and abundance of macroinvertebrate taxa preferred by waterfowl broods were similar across restoration categories and indicated that wetland basins provide ample food resources. We recommend that conservation planners and wetland managers state quantifiable, appropriate objectives for restoration ahead of implementation and address conflicting objectives with stakeholders.