Seventy-Eight Years of Vegetation Dynamics in a Sandhills Grassland

Abstract The Nebraska Sandhills are a unique and valuable grassland resource within the Great Plains with a long history of grazing. In 1926, a vegetation study was established at the Nebraska National Forest Bessey Ranger District to investigate plant community changes in response to heavy grazing. At the time, heavy grazing was being used to shift the grassland plant community dominance from Schizachyrium scoparium (Michx.) Nash (little bluestem) to Bouteloua hirsuta Lag. (hairy grama) in order to create a natural firebreak to protect the adjacent forest from wildfires. Species frequencies were collected from 48, 1-m2 permanent plots in 1926, 1927, 1929, 1931, 1938, 1948, and 1979 to 2004. We evaluated long-term vegetation dynamics by investigating the influence of summer grazing and precipitation on the plant community using Detrended Correspondence Analysis (DCA) and correlations. We determined that grazing had more influence on the plant community than precipitation, with the DCA axis 1 representing ...