摘要
基于遥感和地理信息系统技术,利用1982～2006年间NOAA-AVHRR获得的归一化植被指数(NormalizedDifferenceVegetationIndex,简称NDVI)数据对全球最近25年来的植被生长的动态变化及其与温度、降水的相关关系进行了分析。结果表明:25年间,全球植被生长季NDVI总体上呈显著上升趋势(R^2=0.27,P<0.01),尤其在1982～1997年间(R^2=0.68,P<0.01);而在最近的10年(1997～2006年),全球平均生长季NDVI呈下降趋势(R^2=0.34,P=0.08)。不同地区生长季NDVI变化趋势存在较大差异。1982～2006年间,热带地区生长季NDVI增加速度最快(R^2=0.32,P<0.01),其次为北半球中高纬地区(R^2=0.14,P=0.06),而南半球温带地区平均生长季NDVI主要处于波动中(R^2=0.04,P=0.31)。生长季平均NDVI与气候因子之间相关关系分析表明,北半球中高纬大部分地区植被的NDVI与温度成正相关,说明温度上升对该地区植被生长有利。
Vegetation is a principal component of the terrestrial biosphere, covering 76% of the world＇s land. It has played an important role in the global matter and energy cycles, particularly in buffering the increase of atmospheric CO2 concentration and other greenhouse gas, mitigating water loss and soil erosion, and stabilizing global climate. Therefore, to study the response of vegetation to global climate change has become one of the focuses of current vegetation ecology and global change science. In this study, we used remote sensing data （NOAA-AVHRR） and took,the normalized difference vegetation index（ NDVI） as an indicator of vegetation growth to explore the trends of vegetation growth and their dynamic responses to climate changes from 1982 to 2006. Overall,in those 25 years, the global averaging growing season NDVI significantly increased （R^2= 0. 27 ,P〈0. 01 ）, especially during 1982 to 1997 （ R^2 = 0.68, P〈0.01 ）. This trend, however, has been reversed in 1997 - 2006 （ R^2 = 0.34, P = 0.08 ）. The growing season NDVI also showed remarkably regional differences. In the tropical regions,the growing season NDVI had the largest increase（R^2= 0. 32, P〈0.01 ）, in the mid-high latitude regions of the northern hemisphere, it had trivial increasing（R^2 =0. 14, P = 0.06）, and in the mid-high latitude regions of the southern hemisphere, it was in an unstable change （R^2= 0.04, P〈0.31 ）. Correlation analysis between growing season NDVI and climatic factors shows that in most parts of the northern hemisphere,the growing season NDVI had positive correlations with the annual mean temperature,indicating that warming exerted a positive effect on vegetation growth in these regions.
出处
《第四纪研究》
CAS
CSCD
北大核心
2010年第3期522-530,共9页
Quaternary Sciences
基金
国家自然科学基金项目(批准号:30970511)资助
