© Copyright by the Center for Great Plains Studies ORDINATION AND DESCRIPTION OF PRAIRIE PLANT COMMUNITIES FROM THE SOUTHERN MISSOURI COTEAU IN SOUTH DAKOTA

Abstract. The species composition and soil-site characteristics of three prairies from the Missouri Coteau ofsoutheastern South Dakota were used 1) to determine the major environmental variables responsible for vegeta-tional patterning and 2) to describe the plant communities on these prairies. Vascular plant species composition was significantly correlated (p < 0.01) with a suite ofvariables that strongly influence available soil moisture, and with soil pH and conductivity. Cluster analysis yielded five groups at the 38 % similarity level. From the lowest (in elevation) and most mesic to the highest and most xeric, thefive groups (communities) are: wet meadows with prairie cordgrass (Spartina pectinata Link) and sedge (Carex praegracilis W Boott.) as the most important species; meadows with prairie cordgrass and switch grass (Panicum virgatum L.); swales with Kentucky bluegrass (Poa pratensis L.) and big bluestem (Andropogon gerardii Vitman); slopes with Kentucky bluegrass, sideoats grama (Bouteloua curtipendula [Michx.j Torr.), and needleleaf sedge (Carex eleocharis Bailey); and crests with Kentuck