From Stability to Chaos : analyses on niche separation and population processes generating chaotic dynamics in 1 host-2parasitoid systems

研究了种子甲虫寄主-寄生蜂系统中复杂的种群动态。通过对实验系统的数值模拟，分析了寄主空间分布和寄生蜂各寄主阶段的生态位分离对种群动态的影响。我们建立了资源聚集的系统，其中脆弱的主机位于一个大的资源补丁和资源稀疏的，这些主机被划分为16个小补丁。与资源稀疏条件相比，资源聚集条件下的种群平均规模更大，种群波动更小，表明前者比后者具有更高的种群持续性。此外，对三种寄生蜂实验系统的数值模拟表明，寄生蜂的生态位分离度越大，稳定共存的参数值区域越大。非平衡态的混沌种群行为导致了系统中组分物种的持久性。这些结果表明极限相似理论在非平衡动力学中是成立的。

Complicated population dynamics were investigated in systems of seed beetle hosts and parasitoid wasps. We analyzed effects of hosts' spatial distribution and parasitoids' niche separation for the host stages on population dynamics, based on numerical simulations for experimental systems. We founded resource-clumped systems in which vulnerable hosts were located in one large resource patch and resource-sparse one where those hosts were divided into 16 small patches. The resource-clumped condition showed larger mean population sizes with smaller population fluctuations than the resource-sparse condition did, which suggests the former has more higher population persistence than the latter.Furthermore, numerical simulations for these experimental systems with the three species showed that the larger the parasitoids' niches separate, the larger a region of parametric values for stable coexistence became. Chaotic population behaviors with non-equilibrium dynamics resulted in persistence of the component species in the systems. All these results showed the limiting similarity theory can be supported in non-equilibrium dynamics.