生态学家所面临的一个中心问题是，捕食者与猎物之间的相互作用怎样影响整个生态系统？比如说，旅鼠和它们的捕食者之间的周期动态为什么是受捕食者对旅鼠（作为其食物）的喜好、而不是对其他猎物的喜好影响的？
加州大学的Matthew Holland 和 Alan Hastings利用一个数值模型发现，集中关注在生态学上具有相关性的相互作用（即关注相互作用较强的小型生态系统），将有可能模拟有利于捕食者与猎物的周期不同步、瞬间动态延长的生态系统，正如生态学家在自然界所观察到的那样。这一发现的一个含义是，连接断断续续生境碎片的生态走廊应有一定程度的非对称性，与自然环境相似。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature 456, 792-794 (11 December 2008) | doi:10.1038/nature07395
Strong effect of dispersal network structure on ecological dynamics
Matthew D. Holland1 & Alan Hastings1
1 Department of Environmental Science and Policy, University of California, Davis, One Shields Avenue, Davis, California 95616, USA
A central question in ecology with great importance for management, conservation and biological control is how changing connectivity affects the persistence and dynamics of interacting species. Researchers in many disciplines have used large systems of coupled oscillators to model the behaviour of a diverse array of fluctuating systems in nature1, 2, 3, 4. In the well-studied regime of weak coupling, synchronization is favoured by increases in coupling strength and large-scale network structures (for example 'small worlds') that produce short cuts and clustering5, 6, 7, 8, 9. Here we show that, by contrast, randomizing the structure of dispersal networks in a model of predators and prey tends to favour asynchrony and prolonged transient dynamics, with resulting effects on the amplitudes of population fluctuations. Our results focus on synchronization and dynamics of clusters in models, and on timescales, more appropriate for ecology, namely smaller systems with strong interactions outside the weak-coupling regime, rather than the better-studied cases of large, weakly coupled systems. In these smaller systems, the dynamics of transients and the effects of changes in connectivity can be well understood using a set of methods including numerical reconstructions of phase dynamics, examinations of cluster formation and the consideration of important aspects of cyclic dynamics, such as amplitude.
