2026-01-09 中国科学院(CAS)
<関連情報>
- https://english.cas.cn/newsroom/research_news/earth/202601/t20260113_1145622.shtml
- https://www.nature.com/articles/s41467-025-68252-9
葉レベルの固有水利用効率の地球規模分布と変化および水ストレスへの応答 Global distribution and changes of leaf-level intrinsic water use efficiency and their responses to water stress
Xiang Wang,Zheng Fu,Philippe Ciais,Lixin Wang,Nina Buchmann,Trevor F. Keenan,Martin De Kauwe,Josep Peñuelas,Guo Chen,Xiaoying Gong,Jingfeng Xiao,Xing Li,Qiaoyun Xie,Paul C. Stoy,David Makowski,William K. Smith,Han Wang,Songhan Wang,Fangyue Zhang & Shuli Niu
Nature Communications Published:07 January 2026
DOI:https://doi.org/10.1038/s41467-025-68252-9 An unedited version of this manuscript
Abstract
Intrinsic water use efficiency (iWUE) at the leaf level measures water expenditures by terestrial plants during photosynthesis, yet its global spatiotemporal dynamics and responses to water stress remain poorly understood. Using machine-learning models and carbon isotope observations in C3 foliage, here we elucidate global patterns, trends, and water-stress responses of leaf iWUE. We find high iWUE in cold, arid regions and lower values in warm, humid areas. From 2001 to 2020, global iWUE increases at 0.2 ± 0.02 μmol mol-1 year-1, with strong biome specific differences. Grasslands exhibit the highest mean iWUE but the slowest increase, whereas evergreen broadleaf forests show the lowest iWUE yet the fastest increase. iWUE rises with increasing water stress, but the rate of growth diminishes as water stress intensifies. Vapor pressure deficit influence iWUE more broadly than soil moisture. The ecological optimality model reproduces the spatial patterns of leaf iWUE and identifies vapor pressure deficit as the dominant driver, but overestimates mean iWUE and its trend. Our findings suggest that increasing water stress may slow the rate of global iWUE increase as the climate continues to warm.
