关键词: 若尔盖草原, 沙漠化, 鼠害, 草皮层, 坡面径流

Abstract: As a typical case in formation of aeolian desertification in alpine humid area in China, the Zoige Grassland has been paid great attention for its aeolian desertification. By means of field investigations, interpretation of remote-sensing images, this paper focuses on the role and mechanism of marmots (Marmota himalayana) in formation processes of aeolian desertification on the Zoige Grassland. The results show that the distribution of sand dunes and marmot burrows in hill slope are similar in slope gradient and slope direction. Destruction of turf is the key step in formation of aeolian desertification on the Zoige Grassland. As a kind of large-bodied underlying-dwelling rodents, the burrows digging behavior of marmots plays a vital role in destroying surface turf. Marmot burrow sites are usually located in open, herb-covered talus sunny slopes. The collapse of the large opening of burrows leads to destruction of turf and exposure of loose sands. The exposed loose sands are eroded away, causing collapse of turf which eventually leads to reactivation of fossil sands and formation mobile dunes. During this process, the natural factors such as wind, water, freezing-thawing process, gravitation, human factors, such as overgrazing, livestock activity, have played different roles. Digging of small-bodied animals such as Ochotona curzoniae and Myospalax baileyi can carry sands to the ground. In severe rodent damage area, the rodent mounds covered about 5% of ground and can classed as light degree of aeolian desertification.

Key words: Zoige Grassland, aeolian desertification, rodent damage, turf, slope runoff