Divergent effects of climate change on cropland ecosystem water use efficiency at different elevations in southwestern China  

气候变化对中国西南地区农田水分利用效率影响的海拔差异

作　　者：TAO Jian ZHU Juntao ZHANG Yangjian DONG Jinwei ZHANG Xianzhou 陶健;朱军涛;张扬建;董金玮;张宪洲(School of Public Administratio n,Shand ong Tech no logy and Business University,Yantai 264005,Shandong,China;Nagqu Alpine Grassland Research Station,Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China;Key Laboratory of Land Surface Pattern and Simulation,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China)

机构地区：[1]School of Public Administratio n,Shand ong Tech no logy and Business University,Yantai 264005,Shandong,China [2]Nagqu Alpine Grassland Research Station,Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China [3]Key Laboratory of Land Surface Pattern and Simulation,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China

出　　处：《Journal of Geographical Sciences》2022年第8期1601-1614,共14页地理学报（英文版）

基　　金：National Natural Science Foundation of China,No.41501054;Scientific Research Foundation of Shandong Technology and Business University,No.BS201735;Key Research Program of Frontier Sciences of the Chinese Academy of Sciences,No.QYZDB-SSW-DQC005。

摘　　要：Understanding climatic effects on cropland water use efficiency at different elevations is imperative for managing agricultural water and production in response to ongoing climate change in climate-sensitive areas with complex topography, such as southwestern China. We investigated climatic effects on cropland water use efficiency in southwestern China at each 100-m elevation bin during 2001–2017. The maximum water use efficiency was 1.71 gC kg^(–1) H_2O for the 1900–1999 m elevation bin under the growing season temperature and precipitation of 14.58±0.32℃ and 965.40±136.45 mm, respectively. The water use efficiency slopes were dominated by the evapotranspiration slopes at elevations below 1999 m but were controlled by the gross primary productivity slopes at elevations above 2000 m. This difference was caused by the substantial responses of evaporation to climate change at lower elevations and the increased climatic sensitivity of gross primary productivity at higher elevations. In comparison to those at other elevations, croplands at lower elevations were more vulnerable to extreme drought because of the dominant role fluctuating evapotranspiration played in water use efficiency. The findings will improve cropland water management in the study area.

关 键 词：CROPLAND water use efficiency southwestern China elevational gradient 

分 类 号：P467[天文地球—大气科学及气象学] S181[农业科学—农业基础科学]