Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO, 80309, USA.
Department of Integrative Biology, University of California Berkeley, Berkeley, CA, 94720, USA.
Ecol Lett. 2021 Apr;24(4):772-780. doi: 10.1111/ele.13693. Epub 2021 Feb 8.
The expectations of polar or upslope distributional shifts of species ranges in response to warming climate conditions have been recently questioned. Diverse responses of different life stages to changing temperature and moisture regimes may alter these predicted range dynamics. Furthermore, the climate driver(s) influencing demographic rates, and the contribution of each demographic rate to population growth rate (λ), may shift across a species range. We investigated these demographic effects by experimentally manipulating climate and measuring responses of λ in nine populations spanning the elevation range of an alpine plant (Ivesia lycopodioides). Populations exhibited stable growth rates (λ ~ 1) under naturally wet conditions and declining rates (λ < 1) under naturally dry conditions. However, opposing vital rate responses to experimental heating and watering lead to negligible or negative effects on population stability. These findings indicate that life stage-specific responses to changing climate can disrupt the current relationships between population stability and climate across species ranges.
最近有人质疑物种分布范围在极地或上坡方向上随气候变暖而发生变化的预期。不同生命阶段对温度和湿度变化的不同反应可能会改变这些预测的范围动态。此外，影响人口增长率（λ）的气候驱动因素以及每个人口增长率对人口增长率的贡献（λ）可能会在物种范围内发生变化。我们通过实验性地操纵气候并测量跨越高山植物（Ivesia lycopodioides）海拔范围的九个种群的λ反应来研究这些种群效应。在自然湿润条件下，种群表现出稳定的增长率（λ~1），而在自然干燥条件下，增长率则下降（λ<1）。然而，对实验加热和浇水的生存力反应相反，对种群稳定性几乎没有或没有影响。这些发现表明，对气候变化的特定生命阶段的反应会破坏物种范围内种群稳定性与气候之间的当前关系。
