School of Clinical Sciences, Queen's Medical Centre Campus, Nottingham University Hospital, Derby Road, Nottingham, UK.
Math Biosci. 2013 Nov;246(1):55-71. doi: 10.1016/j.mbs.2013.07.021. Epub 2013 Aug 14.
The current paper accounts for the influence of intra-specific competition among predators in a prey dependent tri-trophic food chain model of interacting populations. We offer a detailed mathematical analysis of the proposed food chain model to illustrate some of the significant results that has arisen from the interplay of deterministic ecological phenomena and processes. Biologically feasible equilibria of the system are observed and the behaviours of the system around each of them are described. In particular, persistence, stability (local and global) and bifurcation (saddle-node, transcritical, Hopf-Andronov) analysis of this model are obtained. Relevant results from previous well known food chain models are compared with the current findings. Global stability analysis is also carried out by constructing appropriate Lyapunov functions. Numerical simulations show that the present system is capable enough to produce chaotic dynamics when the rate of self-interaction is very low. On the other hand such chaotic behaviour disappears for a certain value of the rate of self interaction. In addition, numerical simulations with experimented parameters values confirm the analytical results and shows that intra-specific competitions bears a potential role in controlling the chaotic dynamics of the system; and thus the role of self interactions in food chain model is illustrated first time. Finally, a discussion of the ecological applications of the analytical and numerical findings concludes the paper.
本文研究了捕食者种内竞争对食饵依赖型三营养级食物链模型中种群相互作用的影响。我们对所提出的食物链模型进行了详细的数学分析,以阐明由确定性生态现象和过程相互作用产生的一些重要结果。观察到系统的生物可行平衡点,并描述了它们周围系统的行为。特别是,获得了该模型的持久性、稳定性(局部和全局)和分岔(鞍结分岔、叉形分岔、Hopf-Andronov 分岔)分析。将当前发现的结果与先前著名的食物链模型的相关结果进行了比较。通过构建适当的李雅普诺夫函数进行了全局稳定性分析。数值模拟表明,当自我相互作用率非常低时,当前系统足以产生混沌动力学。另一方面,对于自我相互作用率的某个值,这种混沌行为消失。此外,用实验参数值进行的数值模拟证实了分析结果,并表明种内竞争在控制系统的混沌动力学方面起着潜在的作用;因此,首次说明了自我相互作用在食物链模型中的作用。最后,讨论了分析和数值结果的生态学应用,结束了本文。