Terrestrial ecosystems are in transition

Huan Wang^1*Yuchao Yan²Delong Li³Xiaojun Li⁴Xiangzhuo LIU⁴Lei Fan⁵Mengjia Wang⁶Ying Yao⁷Yiling Cai²Shijie Yan⁸Zanpin Xing⁹Yi Zheng¹⁰Yuqing Liu⁴Jean-Pierre Wigneron^4*

• ¹Peking University, Beijing, China
• ²Sun Yat-Sen University, Guangzhou, China
• ³Chinese Academy of Sciences Institute of Geographic Sciences and Natural Resources Research, Beijing, China
• ⁴Institut National de Recherche pour l'Agriculture l'Alimentation et l'Environnement Centre Nouvelle-Aquitaine Bordeaux, Villenave-d'Ornon, France
• ⁵Southwest University, Chongqing, China
• ⁶Zhengzhou University, Zhengzhou, China
• ⁷College of Urban and Environmental Sciences,peking university, beijing, China
• ⁸Chinese Academy of Sciences Aerospace Information Research Institute, Beijing, China
• ⁹Lanzhou University, Lanzhou, China
• ¹⁰Hainan University, Haikou, China

Global climate change and accelerating human disturbance may trigger biosphere tipping points across a range of scales and push the terrestrial ecosystem undergoing irreversible critical transitions toward alternative ecosystems. The resilience of these systems—their capacity to resist and recover from perturbations and maintain structure and function—is being eroded by multiple drivers, including land-use change, altered disturbance regimes, and biogeochemical imbalances. These drivers interact in nonlinear ways, generating cascading effects across scales and amplifying the risk of state shifts. Increasing evidence based on remote sensing time series suggests that many forests are losing resilience, suggesting an early warning signal for approaching tipping points. Once tipping points are crossed, recovery is highly uncertain or even impossible on human timescales, with profound implications for biodiversity, ecosystem services, and the global carbon cycle. Understanding the mechanisms of resilience loss and identifying early-warning signals of approaching thresholds are therefore central to predicting future ecosystem stability. Due to its ability to monitor key parameters related to vegetation dynamics, remote sensing has emerged as a key tool for monitoring vegetation resilience. This can be done over large areas and with high spatial (about 10 m) and temporal (week-month) resolutions. This review synthesizes current advances on the drivers, evidence, tipping dynamics of terrestrial ecosystems in transition, and advantages of remote sensing in resilience study. We further highlight urgent action to anticipate and manage critical risks, and mitigate climate change in the Anthropocene.