Abstract:

Zoige grassland is a typical area of large-scale desertification of alpine wetland in China， and its desertification causes have always been the focus of research. Marmot is one of the main rodent pests in Zoige grassland. Therefore，it is of great significance to study the relationship between marmot activities and Zoige grassland desertification. High-resolution UAV images，DEM data， and field survey data were used to explore the impacts of marmot caves on grassland desertification in Tangke Town， Zoige County. The following results were obtained through the study. The distribution of sand spots has obvious regularity in altitude and slope. And the distribution of marmot cave is highly similar to that of sand spots in altitude，slope and slope. Marmot caves gather inside the sand spots，around the sand spots， and around the ridges. And the burrowing of marmots intensifies the extension of scarps and pit edges to the side of uncultivated grassland. The density of marmot caves on undesertized grasslands is the smallest. As the degree of grassland desertification deepens，and before extreme desertification，the density of marmot caves increases. When grasslands degrade to shifting sandy lands，the density of marmot caves decreases rapidly.

Key words: marmot caves, sand spots, Zoige Basin, UAV images