Spatiotemporal vegetation cover variations in the Qinghai-Tibet Plateau under global climate change  

作　　者：XU XingKui CHEN Hong Jason K LEVY 

机构地区：[1]Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China [2]Westem Washington University, Huxley College of the Environment, Department of Environmental Studies, 516 High Street, Bellingham, WA 98225, USA

出　　处：《Chinese Science Bulletin》2008年第6期915-922,共8页

基　　金：the National Basic Research Program of China (Grant No. 2006CB403607);the National Natural Science Foundation of China (Grant Nos. 40675047 and 40605023);the Key Project of the Chinese Academy of Sciences (Grant No. KZCX2-YW-219);a Western Washington University summer research grant

摘　　要：Empirical Orthogonal Function (EOF) analysis and the related Principal Components (PC) analysis are used to extract valuable vegetation cover derived information from the National Oceanic and Atmos- pheric Administration (NOAA-AVHRR)'s Leaf Area Index (LAI) satellite images. Results suggest that from 1982 to 2000 global climate change has contributed to an increase in vegetation cover in the Qinghai-Tibet Plateau. The correlation between rainfall and LAI EOF PC1 and PC2 indicates that rainfall is the major climatic factor influencing interannual variations of average vegetation cover throughout the entire Plateau. However, annual mean vegetation cover trends in the Qinghai-Tibet Plateau are mainly out of phase with air temperature increasing, which is primarily responsible for nonsynchro- nous changes of vegetation cover. In the southern ridge of the Qinghai-Tibet Plateau, recent warming trends contribute to humid weather and favorable conditions for vegetation growth. By contrast, higher temperatures have led to arid conditions and insufficient rainfall in the northern part of the Plateau, leading to drought and other climatic conditions which are not conducive to increased vegetation cover.Empirical Orthogonal Function （EOF） analysis and the related Principal Components （PC） analysis are used to extract valuable vegetation cover derived information from the National Oceanic and Atmos-pheric Administration （NOAA-AVHRR）＇s Leaf Area Index （LAI） satellite images. Results suggest that from 1982 to 2000 global climate change has contributed to an increase in vegetation cover in the Qinghai-Tibet Plateau. The correlation between rainfall and LAI EOF PC1 and PC2 indicates that rainfall is the major climatic factor influencing interannual variations of average vegetation cover throughout the entire Plateau. However, annual mean vegetation cover trends in the Qinghai-Tibet Plateau are mainly out of phase with air temperature increasing, which is primarily responsible for nonsynchro-nous changes of vegetation cover. In the southern ridge of the Qinghai-Tibet Plateau, recent warming trends contribute to humid weather and favorable conditions for vegetation growth. By contrast, higher temperatures have led to arid conditions and insufficient rainfall in the northern part of the Plateau, leading to drought and other climatic conditions which are not conducive to increased vegetation cover.

关 键 词：青藏高原 气候变化 植被覆盖率 时空变化 经验正交函数 

分 类 号：P467[天文地球—大气科学及气象学] Q948.15[生物学—植物学]