近日，美国新罕布什尔大学Jingfeng Xiao团队报道了全球植被碳吸收减缓中的旱地优势。相关论文于2026年4月1日发表在《自然—地球科学》杂志上。
大气CO2浓度、温度和饱和水汽压差的上升显著影响植物光合作用和陆地碳吸收，然而这些驱动因子在不同气候区如何交互作用以改变光合作用仍不清楚。
研究组利用全球分布的FLUXNET观测数据以及基于卫星反演、机器学习估算的1982–2022年总初级生产力，揭示了旱地与湿润地区之间植被生产力的非对称性转变。这一转变主要由2001年以来旱地GPP增长速度大幅放缓所导致，其根本原因是与饱和水汽压差上升相关的水分约束。相比之下，湿润地区的GPP对气温上升和大气CO2浓度升高表现出持续增长。
值得注意的是，动态全球植被模型和地球系统模型在历史模拟和未来预估中均未能捕捉到这种差异。考虑到大气干旱加剧和旱地持续扩张，研究组预测全球光合能力将面临广泛的水分约束，这可能限制陆地碳汇。因此，研究组主张在旱地优先采取适应性策略，在湿润地区优先采取基于自然的解决方案，以加强全球气候行动。
附：英文原文
Title: Dryland dominance in the slowdown of global vegetation carbon uptake
Author: Li, Fei, Xiao, Jingfeng, Chen, Jiquan, Ballantyne, Ashley, Peuelas, Josep, Green, Julia K., Tian, Shichao, Zhang, Yingjun, Poulter, Benjamin, Sitch, Stephen, Jin, Jiming, Hu, Xinmiao, Bao, Gang
Issue&Volume: 2026-04-01
Abstract: Rising atmospheric CO2 concentrations, temperature and vapour pressure deficit substantially influence plant photosynthesis and terrestrial carbon uptake, yet how these drivers interact to alter photosynthesis across different climate regimes remains unclear. Here, using globally distributed FLUXNET measurements and satellite-derived machine learning estimates of gross primary production (GPP) for 1982–2022, we reveal an asymmetric shift in vegetation productivity between drylands and humid regions. This shift is led by a substantial slowdown in the rate of increase in dryland GPP since 2001, primarily due to water constraints associated with the rising vapour pressure deficit. By contrast, humid regions exhibit a sustained increase in GPP in response to rising temperatures and atmospheric CO2. Notably, dynamic global vegetation models and Earth system models fail to capture this divergence in both historical simulations and future projections. Given increasing atmospheric aridity and the continued expansion of drylands, we anticipate a broad water constraint on global photosynthetic capacity that may limit the land carbon sink. Consequently, we advocate prioritizing adaptive strategies in drylands and nature-based solutions in humid regions to enhance global climate action.
DOI: 10.1038/s41561-026-01957-8
Source: https://www.nature.com/articles/s41561-026-01957-8