Comparative dataset of plant thermal tolerance in temperate and tropical regions

Dataset compiled for the manuscript: Comparative dataset of plant thermal tolerance in temperate and tropical regionsAbstract: More frequent heatwave events worldwide are leading to leaf scorching, reducing photosynthesis, and contributing to widespread tree mortality. High-temperature thresholds of leaves provide a useful metric of plant heat tolerance and vegetation vulnerability under ongoing climate warming and intensifying heat extremes. However, existing compilations of plant thermal tolerance data are limited by strong methodological inconsistencies, uneven taxonomic and geographical coverage, and incomplete reporting of experimental conditions, all of which constrain cross-study comparability and synthesis. Here, we present the most comprehensive and methodologically harmonized global database of plant thermal tolerance. The dataset focuses exclusively on T50 values derived from ex vivo water-bath experiments combined with chlorophyll fluorescence Fv/Fm measurements, thereby minimizing methodological noise associated with alternative approaches. We curated data from 44 published studies (~58% of the data), integrated unpublished datasets (~34% of the data), and complemented these with new field measurements across temperate regions (~8%). All records were carefully reconciled and annotated for taxonomy, experimental protocol, and metadata, including heat exposure duration, recovery time, growth conditions, sampling context, and climatic background. This resulting database contains 3253 T50 observations spanning 923 species and 160 plant families, covering a broad range of temperate and tropical biomes. Climatic gradients represented in the dataset include mean annual temperatures from 2 to 29 °C, annual precipitation from 73 to 3’809 mm, and elevations from 2 to 3’352 m asl. While cold biomes remain underrepresented, the dataset captures substantial inter- and intra-specific variability in heat tolerance across woody and herbaceous taxa, experimental settings, and environmental contexts. In addition to providing consistently reported T50 values, we provide extensive ancillary information that enables robust comparative and mechanistic analyses, including geographic provenance, growth site conditions, experimental treatments, light exposure, and climate variables derived from global datasets. This dataset offers a valuable resource for advancing comparative studies of plant heat tolerance, quantifying thermal safety margins, and improving predictions of ecosystem responses to future heat extremes.