Wetland hydrologic class change from prior to Euro

Authors: Bradley A Miller William G Crumpton Arnold G van der Valk

Publish Date: 2011/11/29

Volume: 20, Issue: 1, Pages: 1-8

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Abstract

It has been hypothesized that wetland restoration policies have favored the restoration of the wettest classes of wetlands on the Des Moines Lobe of the prairie pothole region To test this hypothesis we compared predrainage wetland distributions based on soils data and National Wetland Inventory NWI estimates of contemporary wetland distributions on the Des Moines Lobe Based on the NWI data the Des Moines Lobe today has only 3–4 of the wetland area that it had prior to the onset of drainage On the basis of their soils predrainage wetlands were predominantly temporarily flooded to saturated wetlands 84 with only about 6 of the wetlands with water regimes classified as semipermanently to permanently flooded Depending on the interpretation of wetland modifiers on NWI maps wetlands classified by the NWI as semipermanent to permanently flooded make up more than 41 of the wetland area while wetlands with temporarily flooded to saturated water regimes account for 45–58 of the Lobe’s wetland area The water regimes of contemporary wetlands when compared to their historic regimes suggest that many of today’s wetlands have different water regimes than they did prior to the onset of drainage Because of the regional lowering of the groundwater table many of today’s wetlands have drier water regimes but some have wetter water regimes because they receive drainage tile inputs Our results indicate that restoration has favored the wettest classes of wetlands and that temporarily to saturated wetland classes have not been restored in proportion to their relative abundance in the predrainage landscapeWe thank two anonymous reviewers and editors for suggestions on previous drafts Support was provided by Ducks Unlimited the Iowa Department of Agriculture and Land Stewardship the United States Department of Agriculture and by the Graduate College the Environmental Science Program the Department of Ecology Evolution and Organismal Biology and the Department of Agronomy at Iowa State University

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