20世纪80年代以来西南喀斯特地区植被变化对气候变化的响应

The response of vegetation dynamics to climate change in the southwestern karst region of China since the early 1980s

气候变化与植被变化的关系已经在全球和区域尺度上得到了研究证明。在前人研究的基础上,基于AVHRR GIMMS NDVI和AVHRR GloPEM NPP数据集,通过对逐个像元信息的提取和分析,研究了20世纪80年代以来,我国西南喀斯特地区植被变化对气候变化的响应。研究结果显示:(1)20世纪80年代以来,西南喀斯特地区植被覆盖度和净初级生产量总体均呈增加的趋势,但不显著。植被指数的年际变化存在着明显的区域差异;(2)植被指数年际变化与气候因子年际变化的相关系数区域分异比较明显;(3)不同的植被类型对气候变化有着不同的响应特征;在该研究区气温变化对植被变化的影响要高于降水量变化对其影响;(4)植被指数年际变化与气候因子年际变化的相关系数在不同气候条件下分布的规律性比较明显。本研究将会增进对影响喀斯特生态系统稳定性的自然过程的认识,同时也会为喀斯特生态系统的管理提供科学依据。

The relationship between climate change and vegetation dynamics has been identified by recent studies in global and regional scales.Based on previous researches and AVHRR GIMMS NDVI and AVHRR GloPEM NPP data sets,this paper analyzes the response of vegetation dynamics to climate change in the southwestern karst region of China since the early 1980s by extracting each pixel＇s information.The results show that：（1） since the early 1980s,both vegetation cover density and net primary production have the ascending tendencies.However,interannual variation rates of vegetation indexes have apparent spatial differentiations;（2） correlation coefficients between the interannual variations of vegetation indexes and the interannual variations of climate factors also have apparent spatial differentiations;（3） various vegetation types have different responses to climate change,and the annual mean temperature variations have more significant impact on vegetation dynamics than the annual precipitation variations;and（4） the distribution laws of correlation coefficients between the interannual variations of vegetation indexes and the interannual variations of climate factors under different climate conditions are apparent.The study of the response of vegetation dynamics to climate change in the southwestern karst region of China will enrich our knowledge of the natural courses which impact the stability of karst ecosystems and provide scientific basis for the management of karst ecosystems.