【作者】 周兆叶； 宜树华； 叶柏生； 任世龙； 许民；

【Author】 Zhou Zhaoye;Yi Shuhua;Ye Baisheng;Ren Shilong;Xu Ming;State Key Laboratory of cryospheric sciences,CAREERI,CAS;

【机构】 中国科学院寒区旱区环境与工程研究所冰冻圈科学国家重点实验室；

【摘要】 全球变暖对多年冻土最直接的影响就是地温升高和活动层厚度增大,导致表层土壤含水量减少,从而对多年冻土区植被产生影响。本文选取祁连山西段的干旱-半干旱区的疏勒河上游地区,分析不同冻土类型区高寒草地NDVI分布特征及变化趋势,建立不同冻土类型区归一化植被指数(NDVI)和地表温度(LST)的关系以探究限制植被生长的因素(热量或水分)。研究结果表明,①从极稳定型到季节性冻土区,NDVI呈倒U形分布特征。②1995年以来,极稳定型、稳定型冻土区NDVI略有增加;亚稳定型、过渡型冻土区NDVI呈增加趋势,植被覆盖状况发生好转;不稳定型、季节性冻土区NDVI呈减少趋势。③从极稳定型到季节性冻土区,植被生长的限制因素从热量过渡到水分。更多还原

【Abstract】 The most direct impact of global warming on permafrost is ground temperature rising and active layer thickening,which will reduce moisture content of surface soil,and then,influence vegetation of permafrost zone.In this study,we studied NDVI distribution and change of the alpine grassland and built relationships between NDVI and land surface temperature(LST) to infer the limiting condition(water and energy) of vegetation growth on the source region of Shule river basin,a semi-arid zone,which locates in the western of Qilian Mountain.Result shows,firstly,distribution of NDVI is in the shape of reversed U from extreme stable permafrost zone to seasonal frost zone.Second,since the 19 95 year.NDVI has increased slightly in extreme stable and stable permafrost zone and more significantly in sub-stable and transition permafrost zone,however,it has decreased in unstable permafrost zone and seasonal frost zone.Moreover,limiting factor of vegetation growth was transitioned from energy in extreme stable permafrost zone to water in seasonal frost zone.更多还原