Project Grant 2140427

This four-year, $643,306 project grant from the National Science Foundation's Biological Sciences program (CFDA 47.074) will fund research into alternative leaf water use strategies employed by plants in hot environments. The grantee, Desert Botanical Garden Inc., will quantify alternative water use behavior across diverse species to determine how common it is for plants to prioritize leaf cooling over photosynthesis when temperatures are high. The research aims to improve modeling of vegetation responses to heat waves and identify species best suited to cope with heat stress. It will combine controlled gas exchange measurements with environmental manipulations and hierarchical modeling. The project's outcomes include determining the prevalence and predictive traits of alternative water use strategies; developing optimality theory on the environmental conditions under which this behavior occurs; and validating predictions along a desert to montane elevation gradient. Findings will advance plant ecophysiology theory, provide a valuable dataset for other researchers, and inform climate model representation of plant water use, ultimately improving climate change scenario predictions. Outreach efforts include developing a bilingual outdoor exhibit at the grantee's public facility to demonstrate heat impacts on plants.