天山北麓中段植被NDVI变化及其对气侯因子的响应

Changes of NDVI Among the Main Vegetation Types and Its Responses to Climatic Factors in the Middle of Northern Slope of Tianshan Mountains

研究特定地区植被覆盖动态及其对气候因子的响应,对植被重建和生态环境恢复具有重要作用。利用1982—2005年NASA/GIMMS半月合成的归一化植被指数(NDVI)和气象数据,分析天山北麓中段各地区不同植被类型NDVI的年际变化特征及其对气候因子的响应。结果表明:(1)近25a来天山北麓中段各地区植被指数均在波动中有所增长,且总体变化趋势保持一致,其变化趋势有利于生态环境的改善;(2)不同地区生长的主要植被类型不同,对整体植被覆盖的贡献不同;(3)不同植被类型对气候因子的响应程度不同,但都与气温和降水存在正相关关系,表明气温和降水是影响植被指数的两个重要自然因素;(4)平原区植被指数增幅大于山区,说明植被生长不仅受自然因素影响,也受人为因素影响。

The exploration of the relationship between the vegetation coverage and climate change plays an significant role on the reconstruction of vegetation and restoration of ecological environment to study the dynamic of the vegetation in specific areas and its influence on climate.NASA/GIMMS half synthetic normalized difference vegetation index（NDVI）from 1982—2005and meteorological data was used to study the characteristic of the NDVI′s annual change and it′s response to the climate factors about different types of vegetation in different regions of the Tianshan Mountains.The results show that：（1）All vegetation index of the Tianshan Mountains increased in the fluctuations of the past 25years,and it was consistent with the overall trend.The trend was conducive to the improvement of ecological environment.（2）The main vegetation in different regions was also different,which had a great impact upon the mixed vegetation index.（3）Different types of vegetation had different response to the climate,but they were all positively correlated with the temperature and precipitation.So it indicated that temperature and precipitation were two important natural factors to affect the vegetation index.（4）The vegetation index in plain increases quickly than it did in the mountains.It indicated that the growth of vegetation was influenced not only by natural factors,but also by human factors.