Data from: Forecasting changes in population genetic structure of alpine plants in response to global warming

Species range shifts in response to climate and land use change are commonly forecasted with species distribution models based on species occurrence or abundance data. Although appealing, these models ignore the genetic structure of species, and the fact that different populations might respond in different ways due to adaptation to their environment. Here, we introduced ancestry distribution models, i.e., statistical models of the spatial distribution of ancestry proportions, for forecasting intra-specific changes based on genetic admixture instead of species occurrence data. Using multi-locus genotypes and extensive geographic coverage of distribution data across the European Alps, we applied this approach to 20 alpine plant species considering a global increase in temperature from 0.25°C to 4°C. We forecasted the magnitudes of displacement of contact zones between plant populations potentially adapted to warmer environments and other populations. While a global trend of movement in a northeast direction was predicted, the magnitude of displacement was species-specific. For a temperature increase of 2°C, contact zones were predicted to move by 92 km on average (minimum of 5 km, maximum of 212 km), and by 188 km for an increase of 4°C (minimum of 11 km, maximum of 393 km). Intra-specific turnover – measuring the extent of change in global population genetic structure – was generally found to be moderate for 2°C of temperature warming. For 4°C of warming, however, the models indicated substantial intra-specific turnover for ten species. These results illustrate that, in spite of unavoidable simplifications, ancestry distribution models open new perspectives to forecast population genetic changes within species, and complement more traditional distribution-based approaches.

为预测物种因气候与土地利用变化引发的分布范围偏移，学界通常采用基于物种出现记录或种群丰度数据的物种分布模型（Species Distribution Models）。尽管此类模型颇具吸引力，但它们忽略了物种的遗传结构，以及不同种群因适应各自环境而对环境变化呈现差异化响应的客观事实。本研究提出了祖先分布模型（Ancestry Distribution Models）——即基于祖先比例空间分布的统计模型——用以基于遗传混合而非物种出现记录，预测物种的种内变化。本研究利用覆盖欧洲阿尔卑斯山区的多位点基因型数据与大范围分布地理数据，针对全球气温从0.25℃升高至4℃的升温情景，将该方法应用于20种高山植物。我们预测了适应温暖环境的植物种群与其他种群之间的接触带的位移幅度。尽管整体呈现向东北方向移动的趋势，但位移幅度因物种而异。当气温升高2℃时，接触带的平均移动距离为92公里（最小5公里，最大212公里）；当气温升高4℃时，平均移动距离则为188公里（最小11公里，最大393公里）。种内更替——用于衡量全球种群遗传结构的变化程度——在气温升高2℃时整体处于中等水平。但当气温升高4℃时，模型显示有10个物种出现了显著的种内更替。本研究结果表明，尽管存在不可避免的简化之处，但祖先分布模型为预测物种种群的遗传变化提供了全新视角，同时可作为传统基于物种分布的模型的补充方法。