Am Nat. 2022 Oct;200(4):598-606. doi: 10.1086/720729. Epub 2022 Aug 16.
AbstractPhenotypic plasticity is the most immediate mechanism of adaptative response to environmental change. Studying plastic changes in response to fluctuating environments provides insights into how such adjustments may impact life history traits. Here, we used a 14-year data set of repeated body mass measurements in male eastern chipmunks () to assess the extent of plastic changes for this trait in a resource pulse ecosystem. We first determined the magnitude of variation in body mass at the population level in response to the drastic change in food resource availability from American beech tree seeds (). Males that emerged in the spring from winter torpor following a nonmast year had a lower body mass than males emerging after a mast year, but they tended to recover this loss by mid-June. We found significant among-individual variation in spring body mass plasticity (i.e., individual-by-environment interaction). We then investigated the relationships between individual spring body mass plasticity, longevity, and lifetime reproductive success. Interestingly, heavier males lived longer than lighter males, but more plastic males had a lower longevity and lower lifetime reproductive success than less plastic males. The report of such plastic response in a stochastic resource system provides valuable insights into the interplay between the costs and benefits of phenotypic plasticity as an adaptation to environmental fluctuations.
摘要表型可塑性是对环境变化的最直接适应机制。研究对波动环境的可塑性变化可以深入了解这些调整如何影响生活史特征。在这里，我们使用了东部花栗鼠雄性个体 14 年的体重重复测量数据集，以评估在资源脉冲生态系统中该特征的可塑性变化程度。我们首先确定了在食物资源可用性（由美洲山毛榉树种子提供）发生剧烈变化的情况下，种群水平上体重的变化幅度。在非丰年进入冬眠的雄性个体在春季从冬眠中苏醒后，体重比在丰年进入冬眠的雄性个体低，但它们往往会在 6 月中旬恢复这种损失。我们发现春季体重可塑性存在显著的个体间差异（即个体-环境相互作用）。然后，我们研究了个体春季体重可塑性、寿命和终生繁殖成功率之间的关系。有趣的是，较重的雄性个体比较轻的雄性个体寿命更长，但较不灵活的雄性个体比较灵活的雄性个体寿命更短，终生繁殖成功率更低。在这种随机资源系统中报告这种可塑性反应，为了解表型可塑性作为对环境波动的适应的成本和收益之间的相互作用提供了有价值的见解。
