Seasonal dynamics of ecosystem services of grassland in Qinghai-Tibetan Plateau
青藏高原草地生态系统服务功能的季节动态变化

Based on the theory of ecosystem services and by using RS and GIS techniques,the ecosystem services of grassland in Qinghai-Tibetan Plateau were analyzed and evaluated,with growth season as time unit.The results showed that the service of supplying biomass presented an up-down-up trend,and the peaks appeared in May and September.Its main affecting factors were PAR,soil moisture condition,and underground biomass.The service of carbon accumulation and oxygen release also presented up-down-up trend,which was related to the supplied biomass and its formation.As for the services of holding soil nutrients and water,the former had a peak in May,while the latter presented staggered variation due to the different water consumption characters of herbages at their different growth stages.