Leaf water potential, net photosynthesis, and aboveground biomass estimates from four Pleuraphis jamesii populations under three different experimental precipitation regimes from 2015-2018

These data represent physiological, growth, and genetic measurements from a common garden experiment designed to test whether Pleuraphis jamesii, a dominant C4 warm-season perennial grass in the southwestern United States, exhibits local adaptation to seasonal precipitation regimes. Individuals from four geographically distinct source populations spanning a precipitation seasonality gradient were grown under three watering treatments simulating spring-dominated, summer-dominated (North American Monsoon), and evenly distributed precipitation patterns. Data include midday leaf water potential, net photosynthesis, and above-ground biomass for each population. These measurements support analyses of plant performance and genetic diversity in relation to precipitation timing and provide insight into species-level plasticity and resilience under shifting climate conditions. The dataset can inform restoration strategies in arid and semi-arid ecosystems facing uncertain precipitation patterns.