Question: What are the past and potential future thresholds of climate change and variability that result in significant High Plains landcover change • Goal: To enhance current understanding of the sensitivity of High Plains landcover to climate and human land-use forcing through an interdisciplinary effort involving remotely-sensed data, paleoclimate analyses, and process modeling. • Approach: 1) document spatial coherency of aridity across the High Plains and improve temporal control on the latest Holocene dune reactivation, 2) constrain the range of land-cover change under specified climate and to understand past High Plains land-cover change, 3) map land-cover responses to hydroclimatic extremes (wet and dry) using LANDSAT images in order to monitor