Regional assessment of wetland plant communities using the index of plant community integrity

The Index of Plant Community Integrity (IPCI) was developed to assess wetland plant communities in the Prairie Pothole Region. The IPCI evaluates the condition of wetland plant communities based on disturbance level and multiple community attributes. However, the index was developed for seasonal wetlands from limited spatial and temporal data. We tested the index for seasonal wetlands and developed an index for temporary and semi-permanent wetlands by evaluating vegetative composition of wetlands throughout the Northern Glaciated Plains and Northwestern Glaciated Plains Ecoregions of South Dakota, North Dakota, and Montana. In 2003 and 2004, we selected wetlands based on classification and type of disturbance, ranging from little disturbance (native rangeland) to heavily disturbed (cropland). We analyzed the data using the IPCI vegetation metrics developed for seasonal wetlands, and further analyzed using nonmetric multidimensional scaling and cluster analyses. All vegetation metrics tested were significant in indicating disturbance level. Based on data analysis, five biologically significant groups related to intensity of disturbance (Very good, Good, Fair, Poor, and Very poor) were determined for seasonal wetlands, and three condition classes (Good, Fair, and Poor) for temporary and semi-permanent wetlands. Score ranges were assigned to the metrics according to the determined classes. Using the IPCI method, wetlands throughout the Northern and Northwestern Glaciated Plains of South Dakota, North Dakota, and Montana may be placed into disturbance classes. This data can then be used for ecological purposes and mitigation needs such as monitoring trends on reclaimed or restored wetlands, regional inventories, and for evaluation of ecological functions.