论文标题
多个吸引子和长期瞬态在空间结构化的群体中具有效果
Multiple attractors and long transients in spatially structured populations with an Allee effect
论文作者
论文摘要
我们提出了一个空间结构化的人群的离散时间模型,并探讨了局部动力学含有强大的合同效应和过度补偿时耦合的效果。尽管孤立的人群只能表现出双重性和本质灭绝,但在空间结构化的人群中可以表现出许多共存的吸引子。我们确定可以保护空间结构群体免受本质灭绝的机制和参数范围,而在本地系统中是不可避免的。在弱耦合的情况下,一个亚群密度位于上方的一个状态,另一个下方阈值以下的状态可以防止基本的灭绝。另一方面,强耦合使两个人群都可以在动态(大约)不相同的情况下持续超过Allee阈值。在这两种情况下,吸引子都有分形盆地边界。在这些参数范围之外,没有发现分散可以防止必要的灭绝。我们还展示了在人口灭绝之前,空间结构如何导致长期持久性。
We present a discrete-time model of a spatially structured population and explore the effects of coupling when the local dynamics contain a strong Allee effect and overcompensation. While an isolated population can exhibit only bistability and essential extinction, a spatially structured population can exhibit numerous coexisting attractors. We identify mechanisms and parameter ranges that can protect the spatially structured population from essential extinction, whereas it is inevitable in the local system. In the case of weak coupling, a state where one subpopulation density lies above and the other one below the Allee threshold can prevent essential extinction. Strong coupling, on the other hand, enables both populations to persist above the Allee threshold when dynamics are (approximately) out-of-phase. In both cases, attractors have fractal basin boundaries. Outside of these parameter ranges, dispersal was not found to prevent essential extinction. We also demonstrate how spatial structure can lead to long transients of persistence before the population goes extinct.