摘要
在全球气候变化背景下,植被动态变化以及植被对气候变化的响应方式已经成为生态学和地理学领域的热点。本文对比分析了南方亚热带季风区将乐县不同类型森林植被对不同时间尺度的干旱响应的差别。基于2000-2017年MODIS-EVI数据及气象站点数据,用最大值合成法、趋势分析法以及相关分析法,分析了森林植被及气象因子的动态变化特征,并对比不同森林植被对气候变化响应的差别。研究表明:①2000-2017年,研究区植被覆盖度、EVI和降水均显著增加,区域内湿度增加,森林长势渐趋良好;②EVI在生长季初期和末期与同期的降水、温度均显著正相关(P<0.1),初期森林受降水因子的影响更大,末期受温度因子的影响大;③1-3月和周年的气候变化对森林的生长至关重要,长时间尺度的湿度增加对森林生长具有显著的促进作用,SPEI的时间尺度越长与EVI的相关性也越大;④针阔混交林与同期温度、降水的相关系数最高,并且与不同时间尺度的SPEI相关性均比较高,属于气候敏感型林型,在生产经营中要谨慎预防气候变化对该林型带来的伤害;⑤森林覆盖度变化与降水和SPEI24的相关性极显著,长时间尺度的降水变化是影响森林植被覆盖率变化的重要因素之一。
Vegetation dynamics and responses to climate change is a hot research topic in the fields of ecology and geography.This paper analyzed and compared the difference in the response of different forest vegetation to different time scales in a Southern subtropical monsoon region.We assessed the dynamics characteristics of forest vegetation and relevant meteorological factors,analyzed the differences in the response of different forest vegetation to climate change.We used the 2000-2017 MODIS-EVI data and meteorological site data,and conducted the maximum value composite(MVC),liner trends,and correlation analyses.We have five major findings.Firstly,in the 18 years,the forest vegetation coverage,EVI,precipitation,and humidity increased significantly,indicating that the forest vegetation has been growing better.Secondly,at the beginning and end of the growing season,there was a significant positive correlation(p<0.1)between EVI and precipitation,so was temperature.At the beginning of the growing season,EVI was more affected by precipitation;while at the end of the growing season,it was more affected by temperature.Thirdly,climate change in the January to March and over the whole year is critically important to forest growth.With increasing time scale,the correlation with EVI and SPEI also increased.The increase of humidity on long-term scales has a positive effect on forest growth.Fourthly,broadleaf-conifer mixed forests have larger correlation coefficients with EVI and meteorological factors than other forest types do.Their correlation with SPEI at different time scales is relatively larger than with meteorological factors.Broadleaf-conifer mixed forests are climate-sensitive;more attention should be paid to their production and management to prevent damages induced by climate change.Fifthly,the correlations of forest cover change with precipitation and with SPEI24 are extremely significant,indicating that the long-term precipitation change is an important factor affecting the change of forest vegetation coverage.
作者
左冰洁
孙玉军
ZUO Bingjie;SUN Yujun(State Forestry Administration Key Laboratory of Foresrty Resources&Environmental Management,Beijing Forestry University,Beijing 100083,China)
出处
《地球信息科学学报》
CSCD
北大核心
2019年第6期958-968,共11页
Journal of Geo-information Science
基金
国家自然科学基金项目(31870620)~~
