新疆植被生产力与叶面积指数的变化及其对气候的响应

The variation of net primary production and leaf area index over Xinjiang Autonomous Region and its response to climate change

利用美国探路者卫星遥感资料AVHRR LAI和全球生态模式CASA给出的植被净初级生产力资料（NPP）对新疆地区1982～2000年的植被时空变化进行了定量分析,结果表明新疆地区的LAI和NPP的空间分布严格受水分的制约,与气温呈负相关,表现出干旱内陆地区植被受降水控制的地带特征.相对于20世纪80年代,90年代整个新疆出现了变暖的趋势,降水基本也呈现增加的趋势,在42°N以北地区暖湿转型尤其明显,与这种气候型相对应,植被出现了明显的增加趋势,NPP最大增幅可达45gCm-2a-1.但植被对气温和降水的年际变化响应不一样,降水主要是影响植被峰值的起落,而植被在总体演变趋势上却主要受气温控制,3个分区1984～2000年的气温明显上升,而降水变化趋势不明显,植被受气温控制出现了显著的上升趋势（P＜0.01）.

The spatiotemporal variations in the vegetation within the Xinjiang Uygur Autonomous Region from 1982 to 2000 were quantified using satellite remote sensing, AVHRR LAI and NPP data from the Carnegie-Ames-Stanford Approach. The results show that the spatial distributions of both NPP and LAI are strictly controlled by the precipitation and are negatively correlated to air temperature. This reflects the topographical characteristics of the vegetation in the arid inland region under limited precipitation. In contrast to the 1980s, the warming trend that occurred in the 1990s and the precipitation both followed an overall increasing trend. To the north of 42 N, this warm-wet climate shift was more obvious. Corresponding to this climate pattern shift, the vegetation increased markedly, with a maximum NPP increment of 45 gC m^-2a^-1. However, vegetation showed a different response to the air temperature and the precipitation on the timescale of interannual changes. The precipitation mainly affected the peak changes in the vegetation, whereas the total temporal variation trend was principally controlled by the air temperature. Temperatures in three sub-regions increased markedly, but the precipitation did not follow any obvious trend. A marked increasing trend （ P 〈 0. 01 ） occurred in vegetation and corresponded to the changes in the temperature.