Department of Environmental and Health Studies, Faculty of Arts and Sciences, Telemark University College, N-3800 Bø, Telemark, Norway; Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Tubney House, Abingdon Road, Tubney, Abingdon, Oxfordshire, OX13 5QL, UK; Animal, Conservation and Education Department, Highland Wildlife Park, The Royal Zoological Society of Scotland, Kincraig, Inverness-shire, PH21 1NL, UK.
Glob Chang Biol. 2012 Sep;18(9):2730-42. doi: 10.1111/j.1365-2486.2012.02739.x. Epub 2012 Jun 27.
Ecologists are increasingly aware of the importance of environmental variability in natural systems. Climate change is affecting both the mean and the variability in weather and, in particular, the effect of changes in variability is poorly understood. Organisms are subject to selection imposed by both the mean and the range of environmental variation experienced by their ancestors. Changes in the variability in a critical environmental factor may therefore have consequences for vital rates and population dynamics. Here, we examine ≥90-year trends in different components of climate (precipitation mean and coefficient of variation (CV); temperature mean, seasonal amplitude and residual variance) and consider the effects of these components on survival and recruitment in a population of Eurasian beavers (n = 242) over 13 recent years. Within climatic data, no trends in precipitation were detected, but trends in all components of temperature were observed, with mean and residual variance increasing and seasonal amplitude decreasing over time. A higher survival rate was linked (in order of influence based on Akaike weights) to lower precipitation CV (kits, juveniles and dominant adults), lower residual variance of temperature (dominant adults) and lower mean precipitation (kits and juveniles). No significant effects were found on the survival of nondominant adults, although the sample size for this category was low. Greater recruitment was linked (in order of influence) to higher seasonal amplitude of temperature, lower mean precipitation, lower residual variance in temperature and higher precipitation CV. Both climate means and variance, thus proved significant to population dynamics; although, overall, components describing variance were more influential than those describing mean values. That environmental variation proves significant to a generalist, wide-ranging species, at the slow end of the slow-fast continuum of life histories, has broad implications for population regulation and the evolution of life histories.
生态学家越来越意识到环境变异性在自然系统中的重要性。气候变化正在影响天气的平均值和变异性，特别是对变异性变化的影响还知之甚少。生物受到其祖先经历的环境变化平均值和范围所施加的选择。因此，关键环境因素的变异性变化可能对重要率和种群动态产生影响。在这里，我们检查了不同气候成分（降水平均值和变异系数（CV）；温度平均值、季节幅度和剩余方差）超过 90 年的趋势，并考虑了这些成分对 13 年来欧亚河狸种群（n=242）的存活率和繁殖率的影响。在气候数据中，没有检测到降水趋势，但所有温度成分的趋势都被观察到，随着时间的推移，平均值和剩余方差增加，季节幅度减小。更高的存活率与以下因素有关（按 Akaike 权重的影响顺序排列）：较低的降水 CV（幼崽和成年主导者）、较低的温度剩余方差（成年主导者）和较低的平均降水量（幼崽和成年主导者）。对非主导成年个体的存活率没有发现显著影响，尽管这个类别样本量很小。更多的繁殖与以下因素有关（按影响顺序排列）：更高的温度季节幅度、更低的平均降水量、更低的温度剩余方差和更高的降水 CV。气候平均值和方差都对种群动态具有重要意义；尽管总体而言，描述方差的成分比描述平均值的成分更具影响力。环境变异性对处于生命历史慢-快连续体缓慢端的一般、广泛分布的物种具有重要意义，这对种群调节和生命历史进化具有广泛的意义。
