Nomoto Hanna, Fior Simone, Alexander Jake
Institute of Integrative Biology, Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland.
Institute of Biology, Functional ecology laboratory, University of Neuchâtel, Neuchâtel, Switzerland.
Evol Lett. 2023 Dec 28;8(1):114-127. doi: 10.1093/evlett/qrad066. eCollection 2024 Feb.
Investigating how climate change alters selection regimes is a crucial step toward understanding the potential of populations to evolve in the face of changing conditions. Previous studies have mainly focused on understanding how changing climate directly influences selection, while the role of species' interactions has received little attention. Here, we used a transplant experiment along an elevation gradient to estimate how climate warming and competitive interactions lead to shifts in directional phenotypic selection on morphology and phenology of four alpine plants. We found that warming generally imposed novel selection, with the largest shifts in regimes acting on specific leaf area and flowering time across species. Competitors instead weakened the selection acting on traits that was imposed directly by warming. Weakened or absent selection in the presence of competitors was largely associated with the suppression of absolute means and variation of fitness. Our results suggest that although climate change can impose strong selection, competitive interactions within communities might act to limit selection and thereby stymie evolutionary responses in alpine plants facing climate change.
研究气候变化如何改变选择机制是理解种群在变化条件下进化潜力的关键一步。以往的研究主要集中在理解气候变化如何直接影响选择，而物种间相互作用的作用却很少受到关注。在这里，我们沿着海拔梯度进行了一项移植实验，以估计气候变暖和竞争相互作用如何导致对四种高山植物形态和物候的定向表型选择发生变化。我们发现，变暖通常会施加新的选择，其中作用于物种特定叶面积和开花时间的选择机制变化最大。相反，竞争者削弱了变暖直接施加在性状上的选择。在有竞争者的情况下，选择减弱或不存在很大程度上与适应度的绝对均值和变异受到抑制有关。我们的结果表明，尽管气候变化会施加强烈的选择，但群落内的竞争相互作用可能会限制选择，从而阻碍高山植物在面对气候变化时的进化反应。
