Degradation causes and sustainable development of grassland in Tianzhu County

230 000 ha grassland accounted for 58.76% of the total grassland area have degraded at Tianzhu County in 2010.At present,the county's natural grassland is still degrading by a rate of 13 300 ha per year.The grassland degradation was caused by both natural factors and human activities.However,over-grazing was a main reason for natural grassland degradation from light to heavy.Therefore,comprehensive countermeasures based on controlling grazing capacity and resolving conflicts between grass and livestock were put forward for natural grassland in the paper,which can help sustainable development of Tianzhu natural grassland and offer technical references for areas of Qilian Mountains on rational utilization of grassland resources and control of degradation.