Data from: Phenotypic plasticity and adaptive evolution contribute to advancing flowering phenology in response to climate change

Anthropogenic climate change has already altered the timing of major life history transitions, such as the initiation of reproduction. Both phenotypic plasticity and adaptive evolution can underlie rapid phenological shifts in response to climate change but their relative contributions are poorly understood. Here, we combine a continuous 38-year field survey with quantitative genetic field experiments to assess adaptation in the context of climate change. We focused on Boechera stricta (Brassicaeae), a mustard native to the U.S. Rocky Mountains. Flowering phenology advanced significantly from 1973-2011, and was strongly associated with warmer temperatures and earlier snowmelt dates. Strong directional selection favored earlier flowering in contemporary environments (2010-2011). Climate change could drive this directional selection, and promote even earlier flowering as temperatures continue to increase. Our quantitative genetic analyses predict a response to selection of 0.2 to 0.5 days acceleration in flowering per generation, which could account for more than 20% of the phenological change observed in the long-term dataset. However, the strength of directional selection and the predicted evolutionary response are likely much greater now than even 30 years ago because of rapidly changing climatic conditions. We predict that adaptation will likely be necessary for long-term in situ persistence in the context of climate change.

人为气候变化（Anthropogenic climate change）已然改变了诸多关键生命史转变的发生时序，例如繁殖启动阶段。表型可塑性（phenotypic plasticity）与适应性进化（adaptive evolution）均可能是响应气候变化的快速物候转变的驱动基础，但二者的相对贡献目前仍未得到充分阐明。本研究结合长达38年的连续野外调查与定量遗传野外实验，以评估气候变化背景下的适应性进化过程。本研究聚焦于原产于美国落基山脉的十字花科（Brassicaeae）植物Boechera stricta。1973年至2011年间，该物种的开花物候（flowering phenology）显著提前，且与气温升高、融雪日期提前呈显著相关性。在2010至2011年的当代环境中，强烈的定向选择（directional selection）青睐开花更早的个体。气候变化可能驱动这类定向选择，并随着气温持续升高进一步推动开花物候提前。我们的定量遗传分析预测，每一代的开花物候将因选择响应提前0.2至0.5天，这一演化响应可解释长期观测数据集中超20%的物候变化量。然而，由于气候条件快速变化，当前的定向选择强度与预测的演化响应强度，很可能远高于30年前的水平。我们预测，在气候变化背景下，适应性进化将是物种实现长期原位存续的必要条件。