集团内捕食模型的动力学分析

发布时间：2018-03-14 16:24

本文选题：集团内捕食　切入点：稳定性　出处：《西南大学》2017年硕士论文　论文类型：学位论文

【摘要】：集团内捕食(Intraguild predation简称IGP)是指享有共同猎物的捕食者之间的捕食现象,即两个捕食者同时以一个猎物为食,而这两个捕食者之间还存在捕食关系的现象.本文建立了两个集团内捕食(IGP)模型,一个是考虑Beddington-DeAngelis功能性反应函数的集团内捕食模型,另一个是考虑IG捕食者具有适应性捕食行为的集团内捕食模型.对第一个模型,本文研究了捕食者之间的相互干扰对种群持续生存与灭绝的影响.通过理论分析和数值模拟,我们发现IG食饵相互间干扰强度的增强导致IG捕食者持续生存的区域变小,进而不利于三个种群共存;而IG捕食者对捕食IG食饵干扰强度的增强使得IG食饵持续生存的区域变得更大,进而有利于三种群共存;当IG捕食者对捕食共享资源的干扰强度增强时,IG食饵持续生存的区域变得更大,进而有利于三个种群共存.对第二个模型,本文讨论了适应性捕食行为对种群持续生存与灭绝的影响.在适应性强度较大时,我们得到模型正平衡点是稳定的,并且发现与一般的捕食系统相比,IG捕食者适应性捕食行为的引入使得正平衡点处IG捕食者的密度增加,进而有利于IG捕食者持续生存;当适应性强度的较弱时,通过数值计算,我们发现系统会出现Hopf分支现象;同时,在一定的适应性强度下,我们发现系统可能会出现富食悖论现象,即IG捕食者为了更好的生存而选择的适应性捕食行为最终可能导致IG捕食者的灭绝.
[Abstract]:Intraguild predation is a predation between predators who share common prey, in which two predators feed on one prey at the same time. In this paper, two intragroup predation models are established, one is the intra-group predation model considering the Beddington-DeAngelis functional response function, and the other is the intragroup predation model, which takes into account the functional response function of Beddington-DeAngelis. For the first model, we study the influence of the interaction between predators on the sustainable survival and extinction of the population, through theoretical analysis and numerical simulation. We find that the increase of the interference intensity between IG prey leads to the decrease of the region where IG predator continues to exist, which is not conducive to the coexistence of the three populations. The increase of the interference intensity of IG prey by IG predator makes the region where IG prey continues to survive becomes larger, which is conducive to the coexistence of the three species. When IG predator interferes with predator-sharing resources, the area where IG prey continues to survive becomes larger, which is conducive to the coexistence of three populations. For the second model, In this paper, we discuss the effect of adaptive predation behavior on the sustainable survival and extinction of the population. When the adaptability intensity is high, we obtain that the positive equilibrium point of the model is stable. It is also found that the introduction of adaptive predation behavior of IG predator increases the density of IG predator at the positive equilibrium point, which is beneficial to the survival of IG predator. At the same time, at a certain degree of adaptability, we find that the system may be rich in food paradox. That is, the adaptive predation behavior chosen by IG predator for better survival may eventually lead to the extinction of IG predator.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O175

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