同类相食对两阶段结构种群模型的动力学影响

Effect of Cannibalism on Dynamics of a Population Model with Two-Stage Structure

研究同类相食对成熟阶段个体具有密度制约的两阶段结构种群的动力学影响,分别分析了不具有同类相食和具有同类相食时两类模型的动力学性态,得到了它们具有相似的动力学性态,即种群灭绝平衡点总存在但不稳定,而种群存在平衡点总存在且是全局渐近稳定的结点.这意味着两个阶段种群密度的最终变化趋势是单调的.同时还讨论了种群存在平衡点的大小对同类相食的依赖性,以及同类相食存在时对种群存在平衡点的大小随自食相关参数的变化.

In this paper, the effect of cannibalism on dynamics of a population model with two-stage structure and density dependence of individuals in mature stage is considered. The dynamical behaviors of two models with/without cannibalism are analyzed respectively. The obtained results show that the two models have similar dynamics. That is, the extinction equi- librium of population always exists but not stable, and the existing equilibrium of population always exists and is globally asymptotically stable node. It implies that both the final trends of the population densities in the two stages are monotonic. Meanwhile, the dependence of the sizes of existing equilibrium, of the population on cannibalism is discussed, and the changes of the existing equilibrium with the cannibalism parameters are also investigated in detail while there is cannibalism between individuals in the two stages.