Data from: Environmental effects on fine-scale spatial genetic structure in four Alpine keystone forest tree species

Genetic responses to environmental changes take place at different spatial scales. While the effect of environment on the distribution of species’ genetic diversity at large geographical scales has been the focus of several recent studies, its potential effects on genetic structure at local scales are understudied. Environmental effects on fine-scale spatial genetic structure (FSGS) were investigated in four Alpine conifer species (five to eight populations per species) from the eastern Italian Alps. Significant FSGS was found for 11 out of 25 populations. Interestingly, we found no significant differences in FSGS across species but great variation among populations within species, highlighting the importance of local environmental factors. Inter-annual variability in spring temperature had a small but significant effect on FSGS of Larix decidua, probably related to species-specific life-history traits. For Abies alba, Picea abies and Pinus cembra, linear models identified spring precipitation as a potentially relevant climate factor associated with differences in FSGS across populations; however, models had low explanatory power and were strongly influenced by a P. cembra outlier population from a very dry site. Overall, the direction of the identified effects is according to expectations, with drier and more variable environments increasing FSGS. Underlying mechanisms may include climate-related changes in the variance of reproductive success and/or environmental selection of specific families. This study provides new insights on potential changes in local genetic structure of four Alpine conifers in the face of environmental changes, suggesting that new climates, through altering FSGS, may also have relevant impacts on plant microevolution.生物对环境变化的遗传响应发生在不同的空间尺度。近年来，诸多研究已聚焦于大地理尺度下环境对物种遗传多样性分布的影响，而其在局域尺度上对遗传结构的潜在效应却尚未得到充分研究。本研究以意大利东阿尔卑斯山区的4种阿尔卑斯针叶树为研究对象，每个物种拥有5至8个种群，探讨了环境对精细空间遗传结构（fine-scale spatial genetic structure, FSGS）的影响。25个种群中有11个呈现出显著的FSGS。有趣的是，研究未发现不同物种间FSGS存在显著差异，但物种种群内部却存在极大变异，这凸显了局域环境因子的重要性。春季温度的年际波动对落叶松（Larix decidua）的FSGS存在微弱但显著的影响，这可能与其物种特异性的生活史特征相关。对于欧洲冷杉（Abies alba）、欧洲云杉（Picea abies）与瑞士石松（Pinus cembra），线性模型识别出春季降水是与种群间FSGS差异相关的潜在关键气候因子；然而这些模型的解释力较低，且受来自极端干旱生境下瑞士石松的离群种群影响显著。总体而言，所识别的效应方向符合预期：更干旱且环境波动更强的环境会提升FSGS。其潜在机制可能包括气候驱动的繁殖成功方差变化，以及/或特定家系的环境选择。本研究为4种阿尔卑斯针叶树在环境变化下的局域遗传结构的潜在变化提供了新见解，表明新的气候环境可通过改变FSGS，对植物微观进化产生重要影响。