A Database of Plant Heat Tolerances and Methodological Matters.

Plant heat tolerance data are increasingly valued for their potential to help increase our understanding of species' responses to extreme temperatures, but these efforts are hindered by methodological inconsistencies and missing contextual information. To address this issue, we collated data on heat tolerance estimates and key sources of variation attributable to taxonomy, methods, geography, and cultivation. The resultant resource is designed to catalyze more rigorous and ecologically meaningful syntheses by enabling researchers to identify, account for, and test the drivers of variation in plant heat tolerances and their consequences. We collected heat tolerance data for terrestrial plants using traditional literature searches and from previously existing databases while expanding the scope of data collected to account for taxonomic, methodological, biogeographic, cultivation, and bibliometric biases. We collected > 3100 heat tolerance records reported in degrees Celsius, from primarily vascular plants encompassing > 1700 taxa, > 1000 genera, and > 200 families from years 1935-2024. Our database more than doubles the species and more than triples the number of records for heat tolerances compared to other databases. Our database is global in scope, but we highlight the lack of standardized methods, undersaturated taxonomic sampling, and underrepresented geographic regions.