Influence of Grazing Treatments on Nutrient, Bacteria, and Suspended Sediment Concentrations and Channel Geometry in the Flint Hills, Kansas

From 1940 to 1960 the number of cows in the United States increased by 60% while the acreage of private grazing land decreased by 15%. As a result there has been increased strain on private rangelands. Cattle grazing is a common land management practice throughout the United States and very prevalent in native remnants of Great Plains prairie grasslands. Cattle have a direct influence on stream morphology due to their summer grazing habits. Cattle graze near riparian vegetation due to water and food availability. Experimental grazing treatments at the Konza Prairie LTER represent an excellent opportunity to study stream channel response to grazing impacts. Thirteen watersheds were evaluated in a paired watershed assessment, with 3 grazed by native bison, 4 grazed by cattle, and 6 ungrazed watersheds, to enable cross-watershed comparative analysis to quantify how do nutrient, bacteria, and sediment characteristics and channel geometry vary between ungrazed, cattle-grazed and bison-grazed watersheds. This is the first study to investigate grazing impacts on Great Plains stream systems and is the first to compare the relative impacts of cattle versus bison grazing habitats. This research addresses the substantial gaps in knowledge regarding the fluvial geomorphic implications of grassland management in the Great Plains.