Causes and dynamic mechanisms of sandy grassland degradation: A study of Otindag sandy land, Inner Mongolia, China
Sandy grassland degradation is an especially serious problem in arid and semiarid region of China.It is hypothesized that such degradation results from external disturbances such as human activities, climate change and management tenure.However, little studies could provide a realistic framework to reveal how the linked geomorphological and ecological system responds to these perturbations in sandy grassland environment.Otindag sandy land is used as a focal study area to describe the response of its geomorphological and ecological system to climatic variables and anthropogenie impacts.Despite that climate warming, human and livestock populations increasing, and management tenure shifting were well recognized from regional climatic and soeio-economie data, the degradation of the study area cannot be attributed to these commonly accepted factors.Our findings show that linked geomorphological and ecological system response to seasonal climatic variables has unique features in the Otindag region, where wind and vegetation alternatively dominate surface proeesses and landscape changes in windy spring and rainy summer, respectively.Such seasonal variations are strongly linked to seasonal shifts of the East Asian monsoon, which should be responsible for any landscape degradation, given removal of anthropogenic impacts.This suggests that sandy grassland degradation should be seen as the result of geomorphological and ecological system response to overgrazing and unwise land management in the face of seasonal climatic variations.Similarly, being situated in the northern marginal zones of the East Asian monsoon and degraded ecosystem syndromes, the other sandy grasslands in the temperate steppe zone of China such as the Hulun Buir, Horqin and Mu Us sandy lands should have the same explanation as above mentioned.Understanding the complex,non-linear ways in which linked geomorphological and ecological system responds to disturbances is important to promote both theoretical understanding and practical grassland management.
Otindag sandy land grassland degradation biogeomorphological processes climatic variability human impacts
Xudong Fu Xinshi Zhang Jim Peterson William Halvorson
State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of S State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of S School of Geography and Environmental Science,Monash University,PO Box 11A,3800,Australia School of Natural Resources and the Environment,University of Arizona,Tucson,AZ 85721-0043,USA
国内会议
北京
英文
50-61
2013-06-29（万方平台首次上网日期，不代表论文的发表时间）