Small-scale patterns in snowmelt timing affect gene flow and the distribution of genetic diversity in the alpine dwarf shrub Salix herbacea

Current threats to biodiversity, such as climate change, are thought to alter the within-species genetic diversity among microhabitats in highly heterogeneous alpine environments. Assessing the spatial organization and dynamics of genetic diversity within species can help to predict the responses of organisms to environmental change. In this study, we evaluated whether small-scale heterogeneity in snowmelt timing restricts gene flow between microhabitats in the common long-lived dwarf shrub Salix herbacea L. We surveyed 273 genets across 12 early- and late-snowmelt sites (that is, ridges and snowbeds) in the Swiss Alps for phenological variation over 2 years and for genetic variation using seven SSR markers. Phenological differentiation triggered by differences in snowmelt timing did not correlate with genetic differentiation between microhabitats. On the contrary, extensive gene flow appeared to occur between microhabitats and slightly less extensively among adjacent mountains. However...当前威胁生物多样性的各类因素（如气候变化）被认为会改变高度异质高山环境中不同微生境的物种种内遗传多样性。评估物种种内遗传多样性的空间组织形式与动态变化，可助力预测生物对环境变化的响应模式。本研究以常见多年生常绿矮灌木高山皱叶柳（Salix herbacea L.）为研究对象，探究融雪时序的小型空间异质性是否会限制其不同微生境间的基因流。我们在瑞士阿尔卑斯山区的12处融雪时序差异显著的样地（分别为山脊与积雪洼地生境）内，对273个基株（genet）开展了为期2年的物候变异调查，并利用7个简单序列重复（Simple Sequence Repeat，SSR）标记检测其遗传变异。研究发现，由融雪时序差异引发的物候分化，并未与不同微生境间的遗传分化呈现相关性。与之相反，不同微生境间存在广泛的基因流，而相邻山地间的基因流程度则略低。然而……