Remote sensing of cytotype and its consequences for canopy damage in quaking aspen

• Published in: Global change biology Vol. 28; no. 7; pp. 2491 - 2504
• Main Authors: Blonder, Benjamin, Brodrick, Philip G., Walton, James A., Chadwick, Katherine Dana, Breckheimer, Ian K., Marchetti, Suzanne, Ray, Courtenay A., Mock, Karen E.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01-04-2022; Wiley-Blackwell
• Subjects: Analytical methods; aspen; Canopies; Canopy; Carbon isotopes; Chromosomes; Copy number; cytotype; Damage; Deoxyribonucleic acid; Diploids; Diploidy; DNA; DNA sequences; DNA sequencing; Drought; Droughts; forest mortality; Gene mapping; Genetic diversity; Genotype-environment interactions; Genotypes; genotype × environment interaction; G×E; hyperspectral; imaging spectroscopy; landscape genetics; Moisture content; Mosaics; Plant cover; Plant species; ploidy level; Populus - genetics; Populus tremuloides; Remote sensing; Remote Sensing Technology; Resolution; Spatial discrimination; Spatial resolution; Spectroscopy; Trees; Triploidy; Water content; cytotype; G×E; imaging spectroscopy; forest mortality; hyperspectral; genotype × environment interaction; landscape genetics; remote sensing; aspen; ploidy level
• ISSN: 1354-1013; 1365-2486
• DOI: 10.1111/gcb.16064

Mapping geographic mosaics of genetic variation and their consequences via genotype x environment interactions at large extents and high resolution has been limited by the scalability of DNA sequencing. Here, we address this challenge for cytotype (chromosome copy number) variation in quaking aspen, a drought‐impacted foundation tree species. We integrate airborne imaging spectroscopy data with ground‐based DNA sequencing data and canopy damage data in 391 km2 of southwestern Colorado. We show that (1) aspen cover and cytotype can be remotely sensed at 1 m spatial resolution, (2) the geographic mosaic of cytotypes is heterogeneous and interdigitated, (3) triploids have higher leaf nitrogen, canopy water content, and carbon isotope shifts (δ13C) than diploids, and (4) canopy damage varies among cytotypes and depends on interactions with topography, canopy height, and trait variables. Triploids are at higher risk in hotter and drier conditions.
Maps of intraspecific genetic variation (here, cytotype, defined as the number of chromosome copies) can be derived from hyperspectral remote sensing over broad regional extents in quaking aspen forests. This genetic variation predicts canopy damage across environmental gradients. Integrating remote sensing and genomics offers useful tools for land management in changing climates.