Heat tolerance plasticity in plants: a global synthesis

January 2023 - May 2023

Publication in prep!

With warming temperatures affecting ecosystems globally, heat tolerance, the upper temperature limit for a species’ survival, has become a prevalent metric of assessing climate change vulnerability. Prior studies have shown that heat tolerance is a plastic trait, with exposure to warm sublethal temperatures can increase thermal limits by acclimation, possibly buffering them against future climate extrema. In this study, we perform the first global meta-analysis of heat tolerance plasticity in plans, synthesizing 100+ studies. Despite more than 70 years of experiments assessing acclimation and the paramount role of plants in building up ecosystem biomass, this is the first assessment of global patterns of plant heat acclimation across phylogeny and geography. We compare plant acclimation to other groups of taxa. The results show that acclimation is prevalent in plants, but is partial and highly variable. Plant acclimation ability was similar to marine ectotherms, but higher than in mobile terrestrial ectotherms capable of behavioral thermoregulation. We then test two prevailing hypotheses to explain variation in acclimation ability based on habitat climate variability and basal heat tolerance.