根据生态系统服务功能理论,利用RS和GIS技术,以生长季为时间单元,对青藏高原研究区草地生态系统服务功能的动态过程进行有效分析和评价.结果表明:提供生物量功能呈现上升-下降-上升的过程,在5月和9月分别出现两个高峰值,其中5月为最高峰值.影响该功能的主要因子为光合有效辐射值、水分状况和地下生物量的季节变化;碳蓄积和氧释放功能呈现上升-下降-上升的弱“N”型趋势;土壤养分保持功能也呈弱“N”型趋势,并在5月份出现最高值;草地保持土壤水分的功能在生长季内呈较强的阶段性变化,这主要与草地植物生长的季节性耗水变化规律有关.
Based on the theory system services of grassland in season as time unit. The results of ecosystem services and by using RS and GIS techniques, the ecoQinghai-Tibetan Plateau were analyzed and evaluated, with growth showed that the service of supplying biomass presented an up-downup 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.