Spatiotemporal characteristics and influencing factors of vegetation water use efficiency on the Tibetan Plateau in 2001–2020  

作　　者：HE Chenyang WANG Yanjiao YAN Feng LU Qi 

机构地区：[1]School of Ecological and Environmental Science,East China Normal University,Shanghai,200241,China [2]Institute of Ecological Conservation and Restoration,Chinese Academy of Forestry,Beijing,100091,China [3]National Climate Center,China Meteorological Administration,Beijing,100081,China

出　　处：《Journal of Geographical Sciences》2025年第1期39-64,共26页地理学报(英文版)

基　　金：National Nonprofit Institute Research Grant of CAF,No.CAFYBB2018ZA004,No.CAFYBB2023ZA009;Fengyun Application Pioneering Project,No.FY-APP-ZX-2023.02。

摘　　要：Water use efficiency(WUE),as a pivotal indicator of the coupling degree within the carbon–water cycle of ecosystems,holds considerable importance in assessment of the carbon–water balance within terrestrial ecosystems.However,in the context of global warming,WUE evolution and its primary drivers on the Tibetan Plateau remain unclear.This study employed the ensemble empirical mode decomposition method and the random forest algorithm to decipher the nonlinear trends and drivers of WUE on the Tibetan Plateau in 2001–2020.Results indicated an annual mean WUE of 0.8088 gC/mm·m^(2)across the plateau,with a spatial gradient reflecting decrease from the southeast toward the northwest.Areas manifesting monotonous trends of increase or decrease in WUE accounted for 23.64%and 9.69%of the total,respectively.Remarkably,66.67%of the region exhibited trend reversals,i.e.,39.94%of the area of the Tibetan Plateau showed transition from a trend of increase to a trend of decrease,and 26.73%of the area demonstrated a shift from a trend of decrease to a trend of increase.Environmental factors accounted for 70.79%of the variability in WUE.The leaf area index and temperature served as the major driving forces of WUE variation.

关 键 词：water use efficiency spatiotemporal characteristic influencing factor Tibetan Plateau 

分 类 号：X171.1[环境科学与工程—环境科学] P339[天文地球—水文科学] Q948[水利工程—水文学及水资源]