Data from: Plasticity in plant hydraulic traits: An evaluation of a common-taxa experiment across a climatic gradient in the Western U.S.

<p>Drought impacts plant productivity, ecosystem function, and the global carbon cycle, with many species-level responses remaining unknown. Variable responses to water availability exist among plant species and across biomes. This research utilized a coordinated water deficit experiment of horticultural taxa across three sites in the Western U.S. to assess taxa-level plasticity to water availability and location. Four taxa (*Cercis occidentalis, Cercis canadensis, Physocarpus ‘*Diabolo’, and *Physocarpus ‘*Little Devil’) were measured for physiological and morphological traits affecting plant hydraulic conductivity under two water deficit treatments. Full gas exchange, specific leaf area, vessel diameter, theoretical hydraulic conductance, and <em>Φ_PSII</em> were collected, and water use efficiencies calculated for each taxon at each location. Impacts of site, treatment, and taxa were analyzed on this suite of traits. Results show differences in taxa performance by climatic location (p < 0.001) and between closely related species and cultivars. However, the irrigation treatments had limited significant impacts on physiological performance. These findings highlight the merits of common-taxa trials over multiple geographic locations to evaluate and identify climate suitability of plants. Our results provide evidence that landscape irrigation can be reduced substantially and utilize a unique research framework for filling plant-water knowledge gaps critical to address in the face of anthropogenic climate change.</p>