Climate Gradients Underlie Geographical Variations in iWUE and δ¹⁵N Values of <i>Encelia</i>.

ABSTRACT: This study assessed variations in leaf intrinsic water use efficiency (iWUE) and δ¹⁵N values among Encelia, a genus of drought-deciduous shrubs distributed across arid regions of southwestern North America between 1972 and 1980 when climates were cooler than today. We hypothesized that geographical variations in climate would significantly influence iWUE, a response to water-related climate constraints, and δ¹⁵N values, a proxy for the balance between N₂ fixation and denitrification. Leaf samples were collected from six species of Encelia across 78 sites representing the genus range. The δ¹⁵N and δ¹³C values of these samples were measured and analyzed to identify drivers of spatial variability. Significant variations amon

SUBMITTER: Lengyel TE 

PROVIDER: S-EPMC12391729 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature