A Review of the cause of rangeland degradation on Qinghai-Tibet Plateau

The principal factors causing Qinghai-Tibet Plateau grassland degradation includes climate,wild life and human activities.Temperature and precipitation are the main elements within climatic.Short term climatic change is not the main factor inducing grassland degradation.From long run,interaction between climate change and grassland degradation can induce the deterioration of grassland ecological system.Small mammals are the principal element affecting grassland,and their damage mainly depend on the population densities.The impact of large,wild herbivores on grassland should not be ignored.Livestock overgrazing is another main factor,to some extent,grazing intensity directly determines the degree of grassland degradation.Although the main causes of grassland degradation vary across different regions,the main causes of grassland degradation in Qinghai-Tibet Plateau are overgrazing and population eruptions of small mammals.Things should be concerned in grassland rehabilitation and management were presented in allusion to the cause of degradation.