Population-level consequences of heterospecific density-dependent movements in predator-prey systems

JOURNAL OF THEORETICAL BIOLOGY

卷:342

Article

Sjodin, Henrik¹  Brannstrom, Ake^2,3  Soderquist, Marten¹  Englund, Goran¹ 

[1] Umea Univ, Dept Ecol & Environm Sci, S-90187 Umea, Sweden

[2] Umea Univ, Dept Math & Math Stat, S-90187 Umea, Sweden

[3] Int Inst Appl Syst Anal, Evolut & Ecol Program, A-2361 Laxenburg, Austria

关键词: Moment closure;    Population dynamics;    Spatial structure;    Species coexistence;    Stochastic processes;   

DOI  :  10.1016/j.jtbi.2013.09.019

来源: Elsevier

【 摘 要 】

In this paper we elucidate how small-scale movements, such as those associated with searching for food and avoiding predators, affect the stability of predator-prey dynamics. We investigate an individual-based Lotka-Volterra model with density-dependent movement, in which the predator and prey populations live in a very large number of coupled patches. The rates at which individuals leave patches depend on the local densities of heterospecifics, giving rise to one reaction norm for each of the two species. Movement rates are assumed to be much faster than demographics rates. A spatial structure of predators and prey emerges which affects the global population dynamics. We derive a criterion which reveals how demographic stability depends on the relationships between the per capita covariance and densities of predators and prey. Specifically, we establish that a positive relationship with prey density and a negative relationship with predator density tend to be stabilizing. On a more mechanistic level we show how these relationships are linked to the movement reaction norms of predators and prey. Numerical results show that these findings hold both for local and global movements, i.e., both when migration is biased towards neighbouring patches and when all patches are reached with equal probability. (C) 2013 Elsevier Ltd. All rights reserved.

【 授权许可】

Free