基于光能利用率模型(CASA),利用2003-2013年的MODIS数据与气象数据估算了祁连山的植被净初级生产力(NPP),在此基础上分析了NPP对气候因子的响应。结果表明:(1)祁连山NPP的年内变化特征明显,生长季在5-9月,东、中部地区7月的NPP值均在89.96 g C·m^-2以上,西部大柴旦仅为12.10 g C·m^-2。(2)从简单相关分析看,野牛沟、乌鞘岭、祁连的NPP在生长季对气温变化的敏感性高于降水,而刚察、托勒、大柴旦、门源的NPP对降水的敏感性高于气温。(3)祁连山NPP对气温和降水的响应均具有显著的滞后效应,滞后期为1个月或3个月,对降水累积滞后表现为1-5个月不等。(4)从偏相关分析看,在生长季RT NPP-P显著偏相关的是祁连、野牛沟、乌鞘岭、刚察,RP NPP-T显著偏相关的是刚察、野牛沟、托勒,对气温和降水敏感性的高低与简单相关分析的结果一致。
Based on the model of Carnegie Ames Stanford Approach (CASA), the net primary productivity (NPP) of Qilian Mountains was estimated with the data of MODIS (from NASA) and meteorological data (from China meteorological science data sharing service) from 2003 to 2013. The response of NPP to climatic factors was further analyzed with the simple correlation analysis and partial correlation analysis. Results show as follows: ( 1 ) there exist obvious annual change of Net primary productivity in Qilian Mountains, with which the growing season is concentrated on five months of a year from May to September. The average values of net primary productivity in July is above 89.96 gC· m^-2 in the east and middle of the Qilian Mountains, while only 12.10 gC· m^-2 in DaChaidan Station in the west of Qilian Mountains. (2) the simple correlation analysis showed that the sensitivity of net primary productivity to the change of temperature was more obvious than that to the change of precipitation in Yeniugou, Wushaoling and Qilian, which was opposite to the phenomenon in Gangcha, Tuole, Dachaidan and Menyuan that the sensitivities of net primary productivity to the change of precipitation was more obvious than that to the change of temperature. (3)there are obvious lag effects of the responses of net primary productivity to temperature and precipitation in Qilian Mountains, and the lag stages were one month or three months, and the lag effects of net primary productivity to cumulative precipitation were differ from one month to five months. (4) the results of partial correlation analysis showed that the net primary productivity to temperature when controlling the precipitation influence in growing season was obviously correlated in Qilian, Yeniugou, Wushaoling and Gangcha, while the net primary productivity to precipitation when controlling the temperature influence was obviously correlated in Gangcha, Yeniugou and Tuole, of which the correlation degrees were the same with those of the simple corr