黄土高原生态系统水分利用效率演变及驱动因素空间分异规律  

Spatial Variation Patterns of Dynamics of Water Use Efficiency of Ecosystem and Its Drivers on the Chinese Loess Plateau

作　　者：常晓格 王志慧[2] 肖培青[2] 魏峰远[1] 张攀[2] 马力 CHANG Xiaoge;WANG Zhihui;XIAO Peiqing;WEI Fengyuan;ZHANG Pan;MA Li(School of Surveying and Land Information Engineering,Henan Polytechnic University,Jiaozuo,Henan 454003,China;Key Laboratory of Soil and Water Conservation on the Loess Plateau,Ministry of Water Resources,Yellow River Institute of Hydraulic Research,Zhengzhou 450003,China)

机构地区：[1]河南理工大学测绘与国土信息工程学院,河南焦作454003 [2]黄河水利科学研究院水利部黄土高原水土保持重点实验室,郑州450003

出　　处：《水土保持研究》2022年第5期244-252,共9页Research of Soil and Water Conservation

基　　金：国家自然科学基金(41701509);中央级公益性科研院所基本科研业务费专项(HKY-JBYW-2020-09)。

摘　　要：生态系统水分利用效率(Water Use Efficiency,WUE)是碳水耦合过程的关键因子,研究黄土高原WUE时空变化及其驱动因素有助于解释生态系统对气候和水资源变化的响应机制以及水资源管理和碳预算评估。论文基于总初级生产力(Gross Primary Productivity,GPP)、蒸散发(Evapotranspiration,ET)、地表覆盖遥感产品和气象观测数据,利用线性斜率和偏相关系数法分析了2000-2018年黄土高原不同植被类型WUE变化趋势及其与降雨(Precipitation,P)、温度(Temperature,Temp)、饱和水汽压差(Vapor Pressure Difference,VPD)、潜在蒸散发(Potential Evaporation,ET_(0))和叶面积指数(Leaf Area Index,LAI)的偏相关性随干旱指数变化的空间分异规律。结果表明:(1)2000-2018年黄土高原多年平均WUE为1.24 gC/(m^(2)·mm),年际增长速率为0.02 gC/(m^(2)·mm·a),其中显著增加区域占47.36%。(2)黄土高原地区各植被类型年均WUE均随干旱指数增加呈显著减小趋势,草地WUE随干旱指数增加下降速率最快。同时,各植被类型WUE的变化速率均为正,但不同植被类型WUE增长速率随干旱指数的变化规律存在差异。受人类活动影响较大的农田WUE增长速率对干旱指数敏感性较低,而林草植被WUE增长速率随干旱指数增加呈先增加后减小的变化规律,存在阈值效应。(3)LAI对WUE的变化影响作用最大,其变化主导的区域占58.16%,其他驱动因素的作用大小依次为Temp,ET_(0),VPD和P。在重度干旱条件下,各植被WUE均与P均呈负相关。与农田和森林相比,灌草植被的WUE与Temp相关性对干旱指数更为敏感。另外,灌草植被的WUE与VPD和ET_(0)的相关性随干旱指数增加也存在阈值效应。Water Use Efficiency(WUE)is a key factor in the carbon-water coupling process.Study on the spatial and temporal variability of WUE on the China Loess Plateau(CLP)and its drivers can help explain the mechanisms of ecosystem response to climate and water resources changes,and also contributes to the management of water resources and the assessment of carbon budgets.Based on satellite remote sensing products,including Gross Primary Productivity(GPP),Evapotranspiration(ET),land cover and meteorological field observations,linear slope method was used to calculate the variation trend of WUE in different vegetation types from 2000 to 2018.Partial correlation coefficient method was employed to explore the variation characteristics of correlations between WUE and precipitation(P),temperature(Temp),vapor pressure difference(VPD),potential evapotranspiration(ET_(0))and leaf area index(LAI)with drought index,respectively changs.The results showed that:(1)the annual mean WUE was 1.24 gC/(m^(2)·mm)in the CLP from 2000 to 2018,and the growth rate of inter-annual WUE was 0.02 gC/(m^(2)·mm·a).Meanwhile,the area with significant increasing trend accounted for 47.36%of the CLP;(2)the annual mean WUE of all vegetation types on the CLP showed a significant decreasing trend with the increase of drought index,among which the decrease rate of WUE of grassland was the fastest with the increase of drought index.Although the variation rate of WUE was positive for all vegetation types,there were differences in the variation pattern of WUE growth rate with drought index for different vegetation types;the WUE growth rate of croplands which were significantly affected by human activities was less sensitive to the drought index,while the WUE growth rate of forest and grass vegetation showed a pattern that increased first and then decreased with the increase of drought index,and there was a threshold effect;(3)the LAI had the greatest effect on the change in WUE,with its change dominating 58.16%of the area,and the other drivers were Temp,ET_(

关 键 词：水分利用效率 空间分异 黄土高原 偏相关分析 驱动因素 

分 类 号：Q948[生物学—植物学]