Great Plains Studies, Center for


Date of this Version

Fall 2011


Great Plains Research 21 (Fall 2011):181- 89


© 2011 Copyright by the Center for Great Plains Studies, University of Nebraska - Lincoln


Historic herbicide use and grazing have influenced natural diversity and quality of native pasturelands in the Great Plains. Floristic quality assessments are useful to assist agencies in prioritizing conservation practices to enhance native grasslands. The objective of this study was to determine the effects of past land-use practices on the floristic quality of remnant native pastures in eastern South Dakota and southwestern Minnesota. Floristic quality assessments were conducted on 30 native pastures and categorized by past management practices (herbicide application and grazing intensity). Mean coefficient of conservatism (C) and floristic quality index (FQI) were calculated for each site~Results showed that increased herbicide use and grazing intensity resulted in a lower species richness, forb C ,and FQI. However, grass and grasslike plants were minimally affected. Pastures that were infrequently sprayed with herbicides and lightly grazed consistently had the highest species richness, C ,and FQI. Pastures with no grazing produced similar values to those with moderate grazing. Pastures managed as preserves or wildlife habitat areas had higher FQI than those managed for livestock grazing. The implications of this study should further help ecologists and managers understand the positive and negative effects of grazing practices and herbicide application on tallgrass prairie remnants.