Genomic vulnerability to rapid climate warming in a tree species with a long generation time. (20th December 2020)

• Record Type: Journal Article
• Authors: Dauphin, Benjamin; Rellstab, Christian; Schmid, Max; Zoller, Stefan; Karger, Dirk N.; Brodbeck, Sabine; Guillaume, Frédéric; Gugerli, Felix
• Is Part Of: Global change biology. Volume 27:Number 6(2021)
• Page Start: 1181
• Page End: 1195
• Publication Date: 2020-12-20
• Subjects: Allele frequency shift -- Alps -- climate change -- conifer -- ecological genomics -- genomic offset -- local adaptation -- risk of non‐adaptedness; Climatic changes -- Environmental aspects -- Periodicals; Troposphere -- Environmental aspects -- Periodicals; Biodiversity conservation -- Periodicals; Eutrophication -- Periodicals; 551.5
• DOI: 10.1111/gcb.15469
• Languages: English
• ISSNs: 1354-1013

Abstract

Abstract: The ongoing increase in global temperature affects biodiversity, especially in mountain regions where climate change is exacerbated. As sessile, long‐lived organisms, trees are especially challenged in terms of adapting to rapid climate change. Here, we show that low rates of allele frequency shifts in Swiss stone pine ( Pinus cembra ) occurring near the treeline result in high genomic vulnerability to future climate warming, presumably due to the species' long generation time. Using exome sequencing data from adult and juvenile cohorts in the Swiss Alps, we found an average rate of allele frequency shift of 1.23 × 10 −2 /generation (i.e. 40 years) at presumably neutral loci, with similar rates for putatively adaptive loci associated with temperature (0.96 × 10 −2 /generation) and precipitation (0.91 × 10 −2 /generation). These recent shifts were corroborated by forward‐in‐time simulations at neutral and adaptive loci. Additionally, in juvenile trees at the colonisation front we detected alleles putatively beneficial under a future warmer and drier climate. Notably, the observed past rate of allele frequency shift in temperature‐associated loci was decidedly lower than the estimated average rate of 6.29 × 10 −2 /generation needed to match a moderate future climate scenario (RCP4.5). Our findings suggest that species with long generation times may have difficulty keeping up with the rapid climate change occurring in high mountain areas and thus are prone to local extinction in their current main elevation range. Abstract : Forest trees are challenged by the rapid pace of climate change due to long life span and generation time, but also limited migration ability. Using tree‐ring, climatic and both empirical and modelled genomic data, we highlight that juvenile tree cohorts of Swiss stone pine, a keystone species of the alpine treeline ecotone, already show signatures of adaptation to current warmer conditions. However, they still exhibit a high genomic risk of non‐adaptedness to future climate. This observation suggests that species with long generation times may have difficulty keeping up with rapid climate change and thus are prone to local extinction.