Dynamics Of Spatial Transmission Of Disease In Food Webs Under The Heterogeneous Environment

Parasitic infection is an important factor affecting the dynamics and stability of biological communities.On the one hand,parasitic species can change population behavioral characteristics through direct mediated effects on host species,thus having important impacts on host dynamics and community structure.For example,parasitism can affect the reproductive rate of host populations and thus has important influence on the abundance of host populations.On the other hand,parasitism can indirectly affect host population dynamics by modulating the characteristics of host populations.The indirect effect of parasitism has an important role in biological invasions and community structure.Recently,research on parasitic infection systems under heterogeneous networks has received much attention,and the spatial transmission dynamics of diseases have become one of the hot issues in the field of mathematical ecology.In this dissertation,by constructing four different heterogeneous network structures,we firstly explored the influence of parasite-regulated population behavioral characteristics on the spatial transmission of infectious disease under different network structures.Secondly,we focus on the effect of parasitic infection on species coexistence in multi-host system with competitive interaction and get feedback on disease transmission.This paper consists of five chapters,Chapter 1 provides an overview of the theory of parasitic infection under heterogeneous networks.Chapter 2 introduces several common infectious disease models and related methods.Chapter 3 constructs a model of host/prey-predator system under heterogeneous networks,and explores effects of parasite-regulated population behavioral traits on the spatial transmission of infectious disease response to by constructing the adaptive network structures.Chapter4 constructs a spatial model of disease transmission between competitors on a regular network,exploring the effects of infectious disease on the species coexistence and considering the relationship between disease prevalence and species coexistence.Chapter 5 concludes the results in the thesis and shows the future perspectives.The main new findings of this thesis are as follows:(1)trait-mediated prey preference and switching behavior towards prey resource can significantly affect disease prevalence and the number of predator individuals;(2)a significantly negative correlation exists between disease prevalence and predator abundance;(3)spatial heterogeneity of network structures can decrease the prevalence of infectious disease and thus inhibit disease transmission;(4)both intra-and interspecific transmission of hosts can change the coexistence of competitive hosts,and intra/interspecific transmission rate leads to an asymmetric effect;(5)species coexistence in the community,i.e.,increasing species diversity,can inhibit disease prevalence,and then revealing the dilution effect of biodiversity.