Population cycles in voles and lemmings : density dependence and phase dependence in a stochastic world
Population cycles in voles and lemmings : density dependence and phase dependence in a stochastic world
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田鼠和旅鼠的种群周期：随机世界中的密度依赖性和相位依赖性
作者：
N. Stenseth
我回顾了北纬地区田鼠和旅鼠多年来的定期种群波动。周期性波动的小啮齿动物种群都表现出清晰的二维密度依赖结构。这意味着直接的和延迟的年密度依赖关系，并表明捕食者-猎物类型的相互作用或专门的植物-食草动物类型的相互作用（但不是两者都有）可能是这些多年密度循环的潜在原因。然而，缺乏与这些命题相关的明确的实验检验。二维年度密度相关结构在某种程度上通常是非线性的，可以建模为非线性的阈值类型，并解释为密度相关结构中的相位相关（这意味着密度相关结构在增加和减少阶段是不同的）。回顾了年密度依赖结构中两个明显的地理梯度：芬诺斯坎德梯度和北海道梯度。进一步分析了年密度依赖结构的季节性质：芬诺斯坎迪亚和北海道田鼠的年密度直接依赖在冬季（每单位时间测量）最强。最后，我对“小型啮齿动物周期”领域的主要挑战进行了调查，其中最大的挑战是人口统计学和种群动态的整合。我建议在其他人群中寻找可能适用的模型系统。我的结论是，在田鼠和旅鼠身上看到的多年种群周期将继续成为种群生态学领域概念和方法发展的强大来源。
I review the regular multiannual population fluctuations in voles and lemmings of northern latitudes. Periodically fluctuating small rodent populations all exhibit a clear two-dimensional density-dependent structure. This implies both a direct and a delayed annual density dependence, and suggests that either a predator-prey type of interaction or a specialised plant-herbivore type of interaction (but not both) may be the underlying cause of these multiannual density cycles. Clear-cut experimental testing relating to these propositions is, however, lacking. A two-dimensional annual density-dependent structure is typically non-linear in a way which may be modelled as a threshold type of non-linearity and interpreted as a phase dependence in the density-dependent structure (implying that the density-dependent structure is different in the increase and the decrease phase). Two clear geographic gradients in the annual density-dependent structure are reviewed: the Fennoscandian gradient and the Hokkaidian gradient. The seasonal nature of the annual density-dependent structure is furthermore reviewed: for voles in both Fennoscandia and Hokkaido the direct annual density dependence during the winter (measured per time unit) is concluded to be the strongest. I close with a survey of the main challenges within the field of small rodent cycles' - the greatest of which is suggested to be the integration of demography and population dynamics. I recommend to look at other populations for potentially applicable model systems. I conclude that multiannual population cycles seen in voles and lemmings will continue to be a strong source of conceptual and methodological developments within the field of population ecology.