意大利佛罗伦萨大学Giovanni Forzieri团队近期取得重要工作进展，他们研究发现气候变化下森林恢复力下降的新迹象。这一成果2022年7月13日在线发表于《自然》杂志上。
在这里，研究人员将基于卫星的植被指数与机器学习相结合，以展示在2000年至2020年期间森林恢复力（根据关键减缓指标量化）的变化情况。他们研究表明，热带、干旱和温带森林的恢复力正在显著下降，这可能与水资源限制增加和气候变化加剧有关。相比之下，北方森林表现出不同的局部模式，恢复力平均呈上升趋势，可能受益于气候变暖和CO2施肥，这可能超过气候变化的不利影响。这些模式在管理森林和完整森林中一致出现，证实了常见的大规模气候驱动因素的存在。
在统计上，恢复力的下降与森林初级生产力的突然下降有关，这是由于缓慢地向临界恢复力阈值漂移而发生的。大约23%的完整未受干扰森林，相当于3.32 Pg C的总初级生产力，已经达到关键的临界阈值，并且正在经历复原力的进一步下降。总之，这些信号表明森林承受扰动的能力普遍下降，在设计基于土地的缓解和适应计划时应考虑到这一点。
据介绍，森林生态系统依赖于它们抵御自然和人为干扰并从中恢复的能力(即它们的恢复力)。树木死亡率突然增加的实验证据引起了人们对森林恢复力变化的担忧，但人们对森林恢复力是如何随着气候变化而变化的知之甚少。
附：英文原文
Title: Emerging signals of declining forest resilience under climate change
Author: Forzieri, Giovanni, Dakos, Vasilis, McDowell, Nate G., Ramdane, Alkama, Cescatti, Alessandro
Issue&Volume: 2022-07-13
Abstract: Forest ecosystems depend on their capacity to withstand and recover from natural and anthropogenic perturbations (that is, their resilience)1. Experimental evidence of sudden increases in tree mortality is raising concerns about variation in forest resilience2, yet little is known about how it is evolving in response to climate change. Here we integrate satellite-based vegetation indices with machine learning to show how forest resilience, quantified in terms of critical slowing down indicators3,4,5, has changed during the period 2000–2020. We show that tropical, arid and temperate forests are experiencing a significant decline in resilience, probably related to increased water limitations and climate variability. By contrast, boreal forests show divergent local patterns with an average increasing trend in resilience, probably benefiting from warming and CO2 fertilization, which may outweigh the adverse effects of climate change. These patterns emerge consistently in both managed and intact forests, corroborating the existence of common large-scale climate drivers. Reductions in resilience are statistically linked to abrupt declines in forest primary productivity, occurring in response to slow drifting towards a critical resilience threshold. Approximately 23% of intact undisturbed forests, corresponding to 3.32PgC of gross primary productivity, have already reached a critical threshold and are experiencing a further degradation in resilience. Together, these signals reveal a widespread decline in the capacity of forests to withstand perturbation that should be accounted for in the design of land-based mitigation and adaptation plans.
DOI: 10.1038/s41586-022-04959-9
Source: https://www.nature.com/articles/s41586-022-04959-9
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
