Modelling analysis embodies drastic transition among global potential natural vegetations in face of changing climate

Potential natural vegetation (PNV) is a valuable reference for ecosystem renovation and has garnered increasing attention worldwide. However, there is limited knowledge on the spatio-temporal distributions, transitional processes, and underlying mechanisms of global natural vegetation, particularly in the case of ongoing climate warming. In this study, we visualize the spatio-temporal pattern and inter-transition procedure of global PNV, analyse the shifting distances and directions of global PNV under the influence of climatic disturbance, and explore the mechanisms of global PNV in response to temperature and precipitation fluctuations. To achieve this, we utilize meteorological data, mainly temperature and precipitation, from six phases: the Last Inter-Glacial (LIG), the Last Glacial Maximum (LGM), the Mid Holocene (MH), the Present Day (PD), 2030 (2021–2040) and 2090 (2081–2100), and employ a widely-accepted comprehensive and sequential classification system (CSCS) for global PNV classification. We find that the spatial patterns of five PNV groups (forest, shrubland, savanna, grassland and tundra) generally align with their respective ecotopes, although their distributions have shifted due to fluctuating temperature and precipitation. Notably, we observe an unexpected transition between tundra and savanna despite their geographical distance. The shifts in distance and direction of five PNV groups are mainly driven by temperature and precipitation, although there is heterogeneity among these shifts for each group. Indeed, the heterogeneity observed among different global PNV groups suggests that they may possess varying capacities to adjust to and withstand the impacts of changing climate. The spatio-temporal distributions, mutual transitions and shift tendencies of global PNV and its underlying mechanism in face of changing climate, as revealed in this study, can significantly contribute to the development of strategies for mitigating warming and promoting re-vegetation in degraded regions worldwide.