ABSTRACT SNOW DEPTH VARIABILITY IN SAGEBRUSH DRIFTS IN HIGH ALTITUDE

In high altitude rangelands, such as those in Colorado, sagebrush and other shrubs can affect transport and deposition of wind-blown snow, thus enabling the formation of snowdrifts. Sagebrush management techniques could have significant effects on snow accumulation patterns. Snow that potentially could have been trapped by the plants may return to the atmosphere through sublimation. Soil moisture and subsequent plant growth may be affected by this sublimation. Measurement of snow depth and the spatial variability of these measurements might be important information for understanding snowdrift formation processes. Determination of the most effective measurement scale for understanding important ecologic and hydrologic processes in this environment is therefore essential. Directional variogram analyses and Moran’s I statistics are two efficient methods for representing the spatial variability of snow depth at different measurement scales in shallow rangeland snow packs. The three following hypotheses are tested to determine the nature of snow depth spatial variability in the high altitude plateau rangeland of North Park, Colorado, using directional variogram analyses and Moran’s I statistical methods: (1) Sagebrush plan