2026-06-28T15:17:18Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/725732025-01-29T12:45:48Zcom_20.500.14352_14col_20.500.14352_15

00925njm 22002777a 4500 dc Méndez Cea, Belén author García García, Isabel author Gazol, Antonio author Camarero, J. Julio author Gónzález de Andrés, Ester author Colangelo, Michele author Valeriano, Cristina author Linares, Juan Carlos author Gallego Rodríguez, Francisco Javier author 2022-10-26 Local differentiation at distribution limits may influence species' adaptive capacity to environmental changes. However, drivers, such gene flow and local selection, are still poorly understood. We focus on the role played by range limits in mountain forests to test the hypothesis that relict tree populations are subjected to genetic differentiation and local adaptation. Two alpine treelines of mountain pine (Pinus uncinata Ram. ex DC) were investigated in the Spanish Pyrenees. Further, an isolated relict population forming the species' southernmost distribution limit in north-eastern Spain was also investigated. Using genotyping by sequencing, a genetic matrix conformed by single nucleotide polymorphisms (SNPs) was obtained. This matrix was used to perform genotype-environment and genotype-phenotype associations, as well as to model risk of non-adaptedness. Increasing climate seasonality appears as an essential element in the interpretation of SNPs subjected to selective pressures. Genetic differentiations were overall weak. The differences in leaf mass area and radial growth rate, as well as the identification of several SNPs subjected to selective pressures, exceeded neutral predictions of differentiation among populations. Despite genetic drift might prevail in the isolated population, the Fst values (0.060 and 0.066) showed a moderate genetic drift and Nm values (3.939 and 3.555) indicate the presence of gene flow between the relict population and both treelines. Nonetheless, the SNPs subjected to selection pressures provide evidences of possible selection in treeline ecotones. Persistence in range boundaries seems to involve several selective pressures in species' traits, which were significantly related to enhanced drought seasonality at the limit of P. uncinata distribution range. We conclude that gene flow is unlikely to constrain adaptation in the P. uncinata rear edge, although this species shows vulnerability to future climate change scenarios involving warmer and drier conditions. Méndez-Cea B, García-García I, Gazol A, Camarero JJ, De Andrés EG, Colangelo M, Valeriano C, Gallego FJ, Linares JC. Weak genetic differentiation but strong climate-induced selective pressure toward the rear edge of mountain pine in north-eastern Spain. Science of The Total Environment 2023; 858: 159778. [DOI: 10.1016/j.scitotenv.2022.159778] 0048-9697 Electronic: 1879-1026 10.1016/j.scitotenv.2022.159778 https://hdl.handle.net/20.500.14352/72573 https://doi.org/10.1016/j.scitotenv.2022.159778 https://www.sciencedirect.com/science/article/pii/S0048969722068784?via%3Dihub Weak genetic differentiation but strong climate-induced selective pressure toward the rear edge of mountain pine in north-eastern Spain