华南三省(区)2001—2020年植被物候时空变化

Temporal and Spatial Variations of Vegetation Phenology in the Three Provinces(Regions)of South China from 2001 to 2020

为深入了解气候变化对我国热带亚热带季风区植被物候的影响,该文基于2001—2020年MODISEVI时序数据,采用Double Logistic法和阈值法提取华南三省(区)植被物候参数,分析了华南三省(区)植被物候的时空变化特征。结果表明,研究区植被返青期主要集中在第90~105天,枯黄期在第320~335天,生长季在第220~235天。20年来植被返青期推迟,枯黄期基本不变,生长季缩短。在空间分布上,返青期在两广地区自西向东、自北向南逐渐推迟,海南则自东北向西南逐渐推迟;枯黄期表现为在两广中部晚、周边早,在海南中部早、周边晚的分布特征;生长季在两广地区整体自西向东逐渐缩短,在海南则自西南向东北逐渐延长。随着海拔增高,不同地区和不同植被的返青期差异较大,且波动性较大,而枯黄期先推迟后提前,生长季先延长后缩短。这揭示了气候变暖背景下华南三省(区)植被物候的变化特征,对更全面认识我国南方植被对气候变暖的响应有指导意义。

In order to understand the effects of climate change on vegetation phenology in tropical and subtropical monsoon regions of China,vegetation phenology parameters in three provinces(regions)of south China were extracted using Double Logistic method and threshold method based on MODIS EVI time series data from 2001 to 2020,and the spatio-temporal variation characteristics of vegetation phenology were analyzed.The results showed that the start of growing season was mainly concentrated in the 90th—105th day,the end of growing season in the 320th—335th day,and the length of growing season in the 220th—235th day.In the past 20 years,the start of growing season was delayed,the end of growing season was basically unchanged,and the length of growing season was shortened.In terms of spatial distribution,the start of growing season gradually delayed from west to east and from north to south in Guangdong and Guangxi,and gradually delayed from northeast to southwest in Hainan.The distribution of wilting period was late in the center and early in the periphery of Guangdong Province,while it was early in the center but late in the periphery of Hainan Province.The length of growing season gradually shortened from west to east in Guangdong and Guangxi,while it gradually extended from southwest to northeast in Hainan.With the increase of altitude,the start of growing season of different regions and different vegetation varied and fluctuated greatly,while the end of growing season was first delayed and then advanced,and the length of growing season was first extended and then shortened.Therefore,these revealed the change characteristics of vegetation phenology in the three provinces(regions)of south China under the background of climate warming,and had guiding significance for more comprehensive understanding of the response of southern vegetation to climate warming.