Stochastic effects contribute to population fitness differences
Stochastic effects contribute to population fitness differences
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DOI：
10.1016/j.ecolmodel.2019.108760
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发表时间：
2019-09-15
影响因子：
3.1
通讯作者：
Jongejans, Eelke
中科院分区：
文献类型：
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作者：
Davison, Raziel;Stadman, Marc;Jongejans, Eelke
人口统计学比率在不同人群之间存在差异，并且随着时间的推移而波动，有时会导致巨大的适应性差异，但随机效应的强度迄今仍未得到解决。我们通过比较长期人口增长的驱动因素来证明随机过程的重要性。我们量化的随机贡献，218种植物和两个动物种群代表62种（所有记录从COMPADRE和COMADRE矩阵数据库适合我们的分析）之间的人口增长率的差异，使用小噪声近似生命表响应实验（SNA-LTRE），最近开发的矩阵模型工具分解的弹性，变异性和相关性的随机贡献。随机影响占种群间人口增长差异的四分之一以上（平均值+/- SD = 28 +/- 14%）。随机效应的相对重要性随着世代时间和寿命的增加而降低，证实了寿命缓冲种群对变异性负面影响的预测。随机效应较大时，人口的增长率差异很大，这表明随机性可能是重要的生态条件变化很大，并在多年生草本植物之间比木本植物，蕨类植物和肉质植物，可能反映了表型可塑性波动的环境。总体而言，我们表明，随机效应往往是强大到足以保证所需的额外努力，以表征其对人口增长的贡献。
Demographic rates differ between populations and also fluctuate over time, sometimes driving large fitness differences, but the strength of stochastic effects remain heretofore unresolved. We demonstrate the importance of stochastic processes by comparing the drivers of long-term population growth. We quantify stochastic contributions to differences in population growth rates among 218 plant and two animal populations representing 62 species (all records from the COMPADRE and COMADRE matrix databases suitable for our analyses) using the Small Noise Approximation Life Table Response Experiment (SNA-LTRE), a recently developed matrix model tool for decomposing the stochastic contributions of elasticities, variability and correlations. Stochastic influences comprise over a quarter of all contributions to population growth variation among populations (mean +/- SD = 28 +/- 14%). The relative importance of stochastic effects decreases with generation time and lifespan, confirming predictions that longevity buffers populations against the negative effects of variability. Stochastic effects are larger when populations differ widely in growth rates, suggesting that stochasticity is likely to be important where ecological conditions vary greatly, and are larger among herbaceous perennials than among woody plants, ferns and succulents, possibly reflecting phenotypic plasticity in response to fluctuating environments. Overall, we show that stochastic effects are often strong enough to warrant the additional effort required to characterize their contributions to population growth.