Mapping temperature thresholds and safety margins of temperate plant species under global change

Global climate change imposes growing challenges to vegetation thermoregulation through rising temperatures and increasing drought frequency. Understanding plant thermal limits (e.g., Tcrit and T50) and their associated temperature safety margins is essential to evaluate canopy resistance to thermal stress. Despite intensified heatwave events in temperate regions, research on plant temperature thresholds has predominantly focused on tropical ecosystems, and methodological inconsistencies have limited cross-study comparability. In this study, we address these knowledge gaps by: (1) quantifying thermal thresholds (Tcrit, T50) for temperate plant species through field sampling, (2) compiling published datasets standardized under a homogenized methodology, (3) analyzing the global drivers of T50 and the inter- and intraspecific variability linked to temperature, phenology, genetics, and methodological factors, and (4) mapping temperature safety margins by integrating field data, upscaling models, and satellite-derived land surface temperatures. Finally, we project future temperature safety margins for temperate vegetation under anticipated climate scenarios. Our findings provide a comprehensive framework to assess and predict the thermal resilience of temperate plant species under ongoing and future climatic stress.