Remote sensing reveals inter‐ and intraspecific variation in riparian cottonwood ( Populus spp) response to drought

作者：Megan Seeley, Benjamin C. Wiebe, Catherine A. Gehring, Kevin R. Hultine, Bradley C. Posch, Hillary F. Cooper, Elena A. Schaefer, Beatrice M. Bock, Andrew J. Abraham, Madeline E. Moran, Arthur R. Keith, Gerard J. Allan, Maya Scull, Thomas G. Whitham, Roberta E. Martin, Gregory P. Asner, Christopher E. Doughty · 发表于：Journal of Ecology · 年份：2025 · DOI：10.1111/1365-2745.70061 · 被引用次数：5 · 研究领域：Plant Water Relations and Carbon Dynamics、Forest ecology and management、Tree Root and Stability Studies

Abstract Understanding how vegetation responds to drought is fundamental for understanding the broader implications of climate change on foundation tree species that support high biodiversity. Leveraging remote sensing technology provides a unique vantage point to explore these responses across and within species. We investigated interspecific drought responses of two Populus species ( P . fremontii , P . angustifolia ) and their naturally occurring hybrids using leaf‐level visible through shortwave infrared (VSWIR; 400–2500 nm) reflectance. As F 1 hybrids backcross with either species, resulting in a range of backcross genotypes, we heretofore refer to the two species and their hybrids collectively as ‘cross types’. We additionally explored intraspecific variation in P. fremontii drought response at the leaf and canopy levels using reflectance data and thermal unmanned aerial vehicle (UAV) imagery. We employed several analyses to assess genotype‐by‐environment (G × E) interactions concerning drought, including principal component analysis, support vector machine and spectral similarity index. Five key findings emerged: (1) Spectra of all three cross types shifted significantly in response to drought. The magnitude of these reaction norms can be ranked from hybrids> P. fremontii > P. angustifolia , suggesting differential variation in response to drought; (2) Spectral space among cross types constricted under drought, indicating spectral—and phenotypic—convergence; (3) ...