Long‐lived larch clones may conserve adaptations that could restrict treeline migration in northern Siberia. Issue 18 (17th August 2020)

• Record Type: Journal Article
• Authors: Kruse, Stefan; Kolmogorov, Aleksey I.; Pestryakova, Luidmila A.; Herzschuh, Ulrike
• Is Part Of: Ecology and evolution. Volume 10:Issue 18(2020)
• Page Start: 10017
• Page End: 10030
• Publication Date: 2020-08-17
• Subjects: adaptation -- clonal growth -- growth rate -- Larix -- leading edge -- treeline migration; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.6660
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: The occurrence of refugia beyond the arctic treeline and genetic adaptation therein play a crucial role of largely unknown effect size. While refugia have potential for rapidly colonizing the tundra under global warming, the taxa may be maladapted to the new environmental conditions. Understanding the genetic composition and age of refugia is thus crucial for predicting any migration response. Here, we genotype 194 larch individuals from an ~1.8 km 2 area in northcentral Siberia on the southern Taimyr Peninsula by applying an assay of 16 nuclear microsatellite markers. For estimating the age of clonal individuals, we counted tree rings at sections along branches to establish a lateral growth rate that was then combined with geographic distance. Findings reveal that the predominant reproduction type is clonal (58.76%) by short distance spreading of ramets. One outlier of clones 1 km apart could have been dispersed by reindeer. In clonal groups and within individuals, we find that somatic mutations accumulate with geographic distance. Clonal groups of two or more individuals are observed. Clonal age estimates regularly suggest individuals as old as 2, 200 years, which coincides with a major environmental change that forced a treeline retreat in the region. We conclude that individuals with clonal growth mode were naturally selected as it lowers the likely risk of extinction under a harsh environment. We discuss this legacy from the past that might now be a maladaptation and hinder expansion under currently strongly increasing temperatures. Abstract : The study features findings of clonal growth and potentially millennial‐long survival in refugia beyond the treeline in northern Siberia for the first time. We conclude that surviving individuals were naturally selected for the ability to spread clonally as it lowers the likely risk of extinction under a harsh environment. We discuss this legacy from the past that might now be a maladaptation and could restrict treeline migration under currently strongly increasing temperatures.