Tropical plants do not have narrower temperature tolerances, but are more at risk from warming because they are close to their upper thermal limits

Tropical plant species, contrary to the common assumption that they have narrower temperature tolerances, are actually more vulnerable to climate warming due to their proximity to upper thermal limits. A global analysis of 9,737 germination records from 1,312 plant species revealed no latitudinal gradient in temperature tolerance breadth. However, tropical plants face significant risks as projected temperatures by 2070 exceed their optimal or even maximum germination thresholds for over half of the studied species. In contrast, most species at latitudes above 45° are expected to benefit from warming, with environmental conditions aligning more closely with their optimal germination temperatures. This study challenges the conventional narrative on plant warming risk and highlights a critical mechanism underlying tropical plant vulnerability.

Sentinella, A. T., Warton, D. I., Sherwin, W. B., Offord, C. A., & Moles, A. T. (2020). Tropical plants do not have narrower temperature tolerances, but are more at risk from warming because they are close to their upper thermal limits. Global Ecology and Biogeography, 29(8), 1387–1398. Portico. https://doi.org/10.1111/geb.13117