Wetland resources of eastern South Dakota; Drainage patterns, assessment techniques, and predicting future risks

This study looks at drainage patterns, landscape impacts on wetland quality, and lastly a method of prioritizing wetlands for conservation in Eastern South Dakota. The first objective of this study was to determine why and where drainage occurred. I found that agricultural conversion was the main reason for wetland drainage and modification and that wetland drainage occurred close to historical drainage districts. A second objective of this study was to explore linkages between land use patterns and wetland condition in eastern South Dakota, and develop and evaluate a rapid assessment protocol for wetlands in the Prairie Pothole Region of Eastern South Dakota. Landscape level assessments were done using the Landscape Development Intensity Index (LDI); in general, nutrient loading indices were positively correlated to LDI, implying that the LDI is useful for characterizing potential wetland disturbance at the landscape level. Using site-specific data, I developed and quantified wetland condition using the South Dakota Wetland Rapid Assessment protocol (SD-WRAP). SD-WRAP scores were strongly correlated to both the LDI and independent expert evaluations. Hence, the SD-WRAP developed here provides a relatively quick and simple approach for gathering site specific data, and can provide an important tool for wetland monitoring and assessment, as well as identify potential reference sites. Lastly, I used a Gap Analysis to try to identify where wetlands might be at risk for being drained or negatively impacted by land conversion. I overlaid areas that relate to wetland drainage and conversion such as landscape disturbance and wetland size to help determine areas in Eastern South Dakota that might be at risk. After completing the Gap Analysis for both high and low risk areas, I found that the percent of public lands are equal in both areas; however there are fewer wetlands on public lands in high risk areas. Gap Analysis could be used to state and federal agencies to help determine where more wetlands should be conserved.;Key words: wetland, South Dakota, land use, wetland assessment, Landscape Development Intensity index, drainage, risk assessment...