Intraspecific variation in stomatal architecture, gas exchange, and drought response of a dominant prairie grass sourced from broad climatic gradients

Premise: Understanding how plant populations adapt to water limitation through stomatal traits is key to predicting drought responses. The dominant C~4 ~grass Andropogon gerardi, distributed across sharp climate gradients in North America, offers an excellent focal species to study stomatal architecture (size and density). Using a common garden, we tested how stomatal architecture relates to home climate, how stomatal architecture influences gas exchange, and how experimental drought affects these responses in a greenhouse. We hypothesized that aridity drives stomatal architecture, and experimental drought reduces stomatal size but increases density to maintain photosynthesis.
Methods: In our first experiment, we measured stomatal architecture and gas exchange in 25 populations sourced across temperature (4–21°C) and precipitation (350–1400 mm yr⁻¹) gradients under well-watered conditions. A second experiment focused on eight populations (472–1356 mm yr⁻¹), subjected..., , # Intraspecific variation in stomatal architecture, gas exchange, and drought response of a dominant prairie grass sourced from broad climatic gradients

Dataset DOI: [10.5061/dryad.pg4f4qs3k](https://doi.org/10.5061/dryad.pg4f4qs3k)

The dataset was collected to investigate the relationships between stomatal architecture, gas exchange, and climate in *Andropogon gerardi* populations under both natural and experimental conditions in a greenhouse. In the main experiment, populations were sampled across a range of climatic gradients to quantify variation in stomatal traits (size and density) and physiological traits (photosynthetic rate, transpiration, stomatal conductance, water-use efficiency, and internal CO₂). In the drought experiment, plants from multiple populations were subjected to control and drought treatments to assess how water limitation influences stomatal traits and gas exchange. Measurements were taken at the population level, and mean values per population were calculate...,