Department of General Systems Sciences, The Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Tokyo 153-8902, Japan.
J Theor Biol. 2012 May 7;300:81-90. doi: 10.1016/j.jtbi.2011.12.011. Epub 2012 Jan 18.
The metacommunity perspective has attracted much attention recently, but the understanding of how dispersal between local communities alters their ecological dynamics is still limited, especially regarding the effect of non-random, unequal dispersal of organisms. This is a study of a three-trophic-level (predator-prey-resource) system that is connected by different manners of dispersal. The model is based on a well-studied experimental system cultured in chemostats (continuous flow-through culture), which consists of rotifer predator, algal prey and nutrient. In the model, nutrient dispersal can give rise to multistability when the two systems are connected by nutrient dispersal, whereas three-trophic-level systems tend to show a rich dynamical behavior, e.g. antisynchronous or asynchronous oscillations including chaos. Although the existence of multistability was already known in two-trophic-level (predator-prey) systems, it was confined to a small range of dispersal rate. In contrast, the multistability in the three-trophic-level system is found in a broader range of dispersal rate. The results suggest that, in three-trophic-level systems, the dispersal of nutrient not only alters population dynamics of local systems but can also cause regime shifts such as a transition to different oscillation phases.
后生境群落观点最近引起了广泛关注，但对于局域群落之间的扩散如何改变它们的生态动力学的理解仍然有限，特别是关于生物非随机、不平等扩散的影响。这是一项关于通过不同方式扩散连接的三营养级（捕食者-猎物-资源）系统的研究。该模型基于在恒化器（连续流动培养）中培养的一种经过充分研究的实验系统，该系统由轮虫捕食者、藻类猎物和营养物组成。在模型中，当两个系统通过营养物扩散连接时，营养物扩散会导致多稳定性，而三营养级系统往往表现出丰富的动力学行为，例如包括混沌的非同步或异步振荡。虽然多稳定性在两营养级（捕食者-猎物）系统中已经存在，但它仅限于较小的扩散率范围。相比之下，三营养级系统中的多稳定性存在于更广泛的扩散率范围内。结果表明，在三营养级系统中，营养物的扩散不仅改变了局域系统的种群动态，还可能导致诸如向不同振荡阶段转变的状态转变。
