The Dynamical Analysis Of IGP Models

Intraguild predation(IGP)is a phenomenon that two consumers share a com-mon resource and also engage in a predator-prey interaction.This thesis inves-tigate two intraguild predation models:one has Beddington-DeAngelis functional response function,while the other one consider adaptive predator.For the first model,we study the effect of mutual interference among preda-tors on population persistence and extinction.Through theoretical analysis and numerical simulation,we find that the increase of the interference intensity between IG prey leads to smaller parameter region where IG predator can persist,which implies that the coexistence region of three populations become smaller.It is also found that the increase of the interference intensity between IG predators make the persistent region of IG prey become larger and then help to coexist of the three species.For the second model,we discuss the influence of adaptive predation to popu-lation persistence and extinction.When the adaptive intensity is larger,we prove that the positive equilibrium is stable,and it is found that the adaptive predation of IG predator leads to larger density of IG predator at positive equilibrium com-pared with the normal predator-prey system without adaptive predation.When the strength of adaptive predation is weak,through numerical calculation,we find that there exists hopf bifurcation,which implies that the adaptive predation behav-ior of IG predator may lead to the extinction of the IG predator.At the same time,we also find that it is possible for the appearance of the paradox of enrichment for some fixed adaptive predation.