Limit cycles in Norwegian lemmings: Tensions between phase-dependence and density-dependence
Limit cycles in Norwegian lemmings: Tensions between phase-dependence and density-dependence
复制标题
DOI：
10.1098/rspb.1997.0005
复制
发表时间：
1997-01-22
影响因子：
4.7
通讯作者：
Falck, W
中科院分区：
文献类型：
--
作者：
Framstad, E;Stenseth, NC;Falck, W
自从埃尔顿以来，芬诺斯坎迪亚的旅鼠（和其他微齿动物）3-5年的密度周期一直困扰着科学家。进化涉及内在调节和营养相互作用。我们已经分析了每年的变化，秋季丰富的旅鼠超过25年，从当地的两个山区在挪威南部。这些时间序列似乎有一个潜在的二阶非线性结构。拟合分段线性阈值模型的最大阶2，最简约的模型，但是，一阶的两个系列。从这个模型得到的动态是一个极限环。重新制定的丰度方面的模型产生一个模型，结合（延迟）密度依赖的影响和循环阶段的影响。延迟的密度依赖模型的一部分是一致的专业捕食者在高峰和崩溃阶段的周期的影响，虽然不能排除其他营养相互作用。
Ever since Elton, the 3-5 year density cycles in lemmings (and other microtines) in Fennoscandia have troubled scientists. Explanations have involved intrinsic regulation and trophic interactions. We have analysed yearly changes in fall abundances for lemmings over 25 years from two local mountain sites in South Norway. These time series appear to have an underlying nonlinear structure of order two. Fitting a piece-wise linear threshold model of maximum order two, the most parsimonious model was, however, of first order for both series. The resulting dynamics from this model is a limit cycle. Reformulating the model in terms of abundances yields a model which combines (delayed) density-dependent effects and the influence of the cyclic phase. The delayed density-dependence of one part of the model is consistent with an effect of specialist predators during the peak and crash phases of the cycle, although other trophic interactions cannot be excluded.