赣江上游区LAI时空变化及其与气候要素的关联性分析

Spatio-Temporal Variation of LAI and Its Relationship with Climate Change in the Upper Ganjiang River Region

受全球气候变化影响,陆地植被呈明显的动态变化特性,植被对气候变化的响应关系已成为气候学、生态学领域的热点问题。选取赣江上游峡山水文站以上集水区为研究区,基于1982~2014年气象和叶面积指数(LAI)数据,分析研究区气候要素和LAI的时空演变特征,剖析LAI与气候要素的关联性,解译研究区LAI对气候变化的响应机制。结果表明:研究区近33年气温呈显著升高趋势,降水呈不显著的减少趋势,日照时长总体为增加趋势;研究区LAI显著增加,通过比较研究区5景不同时期土地利用图发现人类活动对陆地植被的影响不明显,气候要素是引起LAI动态变化的主导因素;LAI对各气候要素的敏感度由高至低:气温>日照时长>降水。

Impacted by global climate change,the characteristics of land vegetation are dynamically changing,and the response of land vegetation to climate change has become a hot issue in the field of climatology and ecology.Based on meteorological data and leaf area index(LAI)data from 1982 to 2014,the spatial and temporal distribution and evolution characteristics of climate factors and vegetation were analyzed in the drainage area controlled by the Xiashan hydrological station in the upper reach of the Ganjiang River.Meanwhile,the correlation between LAI and climatic factors were analyzed to indicate the mechanism on how LAI responses to climate change.The study found that in the recent 33 years,the local air temperature increased significantly,precipitation was in an insignificant decrease trend,and sunshine duration was generally in rise.LAI mainly represents an increasing trend.The comparison of the land-use maps in five time periods demonstrates that human activity has an unobvious impact on local vegetation and climate change is the dominant factors for the change of LAI.In general,LAI is most sensitive to the change of air temperature,followed by sunshine duration,and LAI is least sensitive to the precipitation change.