基于MODIS NDVI的西南森林植被时空变化特征及其气候响应分析  

Spatial-Temporal Variations of Forest Vegetation and Climatic Driving Force Analysis in Southwest China Based on MODIS NDVI and Climate Data

作　　者：曹云 钱永兰 孙应龙 钱拴 张晔萍[2] 延昊 CAO Yun;QIAN Yonglan;SUN Yinglong;QIAN Shuan;ZHANG Yeping;YAN Hao(National Meteorological Center,Beijing 100081,China;National Satellite Meteorological Center,Beijing 100081,China)

机构地区：[1]国家气象中心,北京100081 [2]国家卫星气象中心,北京100081

出　　处：《生态环境学报》2020年第5期857-865,共9页Ecology and Environmental Sciences

基　　金：国家重点研发计划(2016YFC0503402-05);中国气候变化专项课题成果《2000年以来中国植被生态改善的气候归因研究》;国家气象中心生态气象监测评估创新团队。

摘　　要：基于2000—2017年西南地区的390个气象站逐日气象数据,结合MODIS NDVI的遥感资料,运用趋势分析、相关分析和空间分析等方法,研究西南林区植被时空分布特征,探讨不同气候因子对森林生长的影响。结果显示,(1)近18年西南林区年平均NDVI多集中于0.6—0.7之间,占林区总面积44.1%。NDVI≥0.7林区面积所占比例达到24.1%,主要分布在云南西部和南部,多为常绿阔叶林。(2)2000—2017年西南林区NDVI呈显著上升趋势,平均每10年增加0.035,其中重庆森林NDVI增加速率最高,达到0.06/(10 a)。NDVI在不同森林类型间具有显著差异,西南常绿阔叶林NDVI最高,落叶针叶林最低。(3)2000年以来有86.7%的林区NDVI呈增加趋势,其中73.1%林区增加趋势达到显著水平。对于不同NDVI等级,NDVI≥0.7的林区面积呈显著增加趋势,而NDVI<0.6的林区面积呈显著减少趋势,表明近18年西南林区植被改善的面积要明显高于退化面积。(4)在波动分析中,高稳定等级的林区主要分布于四川西部和云南西北部等地,占总林区面积33.76%,而低稳定、较低稳定等级的林区分布在四川盆地与川西高原边界地区,仅占7.45%。不同森林类型具有不同稳定性,落叶针叶林稳定性最好,灌丛稳定性最差。(5)在气候变化响应方面,有60%—80%林区在年尺度上与降水和温度具有正相关性,但与日照呈负相关性。有30.3%林区与温度的相关性达到显著水平,与降水、日照达到显著相关的林区面积较少,分别占总林区面积8.7%、9.4%,表明温度是西南森林生长的关键影响因子。本研究结果有利于揭示气候变化下西南不同森林类型NDVI变化规律,可为西南林区生态保护提供基础数据和科学参考。Forest dynamics in response to climate change are critical in the field of climate-vegetation feedback.This study investigated the spatial-temporal changes in forest vegetation and climate from 2000 to 2017 in Southwest China by using statistical methods including trend and correlation analysis.MODIS Normalized Difference Vegetation Index(NDVI)dataset and climate data from 390 meteorological stations were used in this study.The results showed that,(1)The annual average NDVI(ANDVI)of forest in Southwest China ranged from 0.6 to 0.7 during 2000 to 2017.Forests with ANDVI≥0.7 mainly distributed in the western and southern regions of Yunnan Province,occupying 24.1% of total forest area.Large differences were found in ANDVI for different forest types.Evergreen broadleaf forest had the highest ANDVI of 0.72,while deciduous needleleaf forest had the lowest ANDVI of 0.56.(2)Forest ANDVI in Southwest China increased by 0.035/(10 a)from 2000 to 2017.The highest increasing rate of ANDVI was 0.06/(10 a)recorded for forests in Chongqing.(3)Totally,ANDVI increased(P<0.05)over 73.1% of forest regions from 2000 to 2017 due to forest growing.As a result,forests with ANDVI≥0.7 occupied more area,while forests with ANDVI<0.6 occupied less area.(4)Forest stability,defined by the coefficient of variation(CV),changed with spatial regions and forest types.The highest forest stability area was mainly distributed in the western part of Sichuan and northwestern Yunnan province,accounting for 33.76% of total forest area;while the lowest stability and lower stability were in the edges of Sichuan Basin and the West Sichuan Plateau respectively,accounting for only 7.45% of the total forest area.In addition,the highest stability was recorded for deciduous needleleaf forest,and the lowest stability was recorded for shrubland.And(5)correlation analysis revealed that forests,covering 30.3% of the total forest area,had a positive correlation(P<0.05)between ANDVI and temperature.ANDVI of 8.7%and 9.4% forest significantly correlated with precipi

关 键 词：NDVI 时空变化 气温 降水 气候变化 相关性 

分 类 号：Q948[生物学—植物学] S718.5[农业科学—林学]