Ceresa Francesco, Brambilla Mattia, Kvist Laura, Vitulano Severino, Pes Michele, Tomasi Laura, Pedrini Paolo, Hilpold Andreas, Kranebitter Petra
Museum of Nature South Tyrol, Bolzano, Italy.
Dipartimento di Scienze e Politiche Ambientali, Università degli Studi di Milano, Milan, Italy.
Mol Ecol. 2023 Apr;32(8):1875-1892. doi: 10.1111/mec.16853. Epub 2023 Feb 2.
Species living in high mountain areas are currently threatened by climate change and human land use changes. High-elevation birds frequently inhabit island-like suitable patches around mountain peaks, and in such conditions the capability to exchange individuals among patches is crucial to maintain gene flow. However, we lack information regarding the dispersal ability of most of these species and the possible influence of landscape features on dispersal. In this study, we used population genomics and landscape resistance modelling to investigate dispersal in a high-elevation specialist migratory bird, the water pipit Anthus spinoletta. We aimed to assess the levels of gene flow in this species within a wide area of the European Alps, and to assess the effects of environmental characteristics on gene flow, by testing the isolation by distance (IBD) hypothesis against the isolation by resistance (IBR) hypothesis. We found clear support for IBR, indicating that water pipits preferentially disperse across suitable breeding habitat (i.e., high-elevation grassland). IBR was stronger in the part of the study area with less extended suitable habitat. Landscape resistance was slightly better described by habitat suitability models than landscape connectivity models. Despite the observed IBR, gene flow within the study area was high, probably also because of the still wide and relatively continuous breeding range. The forecasted reduction of range of this species may lead to stronger effects of IBR on gene flow. Other high-elevation specialist birds may show similar IBR patterns, but with possibly stronger effects on gene flow because of their more reduced and patchy habitats.
生活在高山区的物种目前正受到气候变化和人类土地利用变化的威胁。高海拔鸟类经常栖息在山峰周围岛屿状的适宜斑块中，在这种情况下，斑块间个体交换的能力对于维持基因流动至关重要。然而，我们缺乏关于这些物种中大多数的扩散能力以及景观特征对扩散可能产生的影响的信息。在本研究中，我们使用种群基因组学和景观抗性建模来研究一种高海拔特化候鸟——水鹨（Anthus spinoletta）的扩散情况。我们旨在评估该物种在欧洲阿尔卑斯山广大区域内的基因流动水平，并通过检验距离隔离（IBD）假说与抗性隔离（IBR）假说，来评估环境特征对基因流动的影响。我们发现IBR得到了明确支持，这表明水鹨优先在适宜的繁殖栖息地（即高海拔草地）上扩散。在研究区域中适宜栖息地范围较小的部分，IBR更强。栖息地适宜性模型比景观连通性模型对景观抗性的描述稍好一些。尽管观察到了IBR，但研究区域内的基因流动水平较高，这可能也是因为繁殖范围仍然广阔且相对连续。该物种预测的分布范围缩小可能会导致IBR对基因流动产生更强的影响。其他高海拔特化鸟类可能会表现出类似的IBR模式，但由于它们的栖息地更加破碎且范围更小，对基因流动的影响可能更强。
