The Impact Of Interspecific Interactions On Ecosystem Stability

According to the theory of ecology,the complex community composed of a large number of species is essentially unstable.Through research,May proved theoretically that the more complex the ecosystem,the lower the stability of the ecosystem,which seems to be contrary to our understanding of nature,so led scientists to further explore the reasons for maintaining the diversity of natural species.Recent studies have found that the type of interaction may be the reason why we understand the stability of complex ecosystems.In some studies,some conclusions are obtained under the assumption of equal population density.Although it is convenient to study,it ignores the population density of the real community.Therefore,in this paper,under the structure of random network and small-world network,Lotka-Volterra model is convenient,which includes the interaction type parameters and is widely used to study ecology.We calculate the population density with the Gauss algorithm,which is in accordance with the ecological hypothesis and different from the previous research.The population density we calculated here is not equal.Then,under the linear stability analysis method,the influence of the interaction type between species on the community stability was studied.There are two indicators,the probability indicator and the dynamics indicator,to indicate the community stability.In the random structure,first of all,when there are two kinds of interactions in the community,it was found that the appropriate mixture of competition and predator is conducive to the stability of the community,and the appropriate mixture of competition and mutualism,as well as the appropriate mixture of predator and mutualism is conducive to the stability of the community.Next,when there are three kinds of interactions of the community,it was found that competition is conducive to the stability of the community with an appropriate proportion;predator-prey is not conducive to the stability of the community;mutualism is conducive to the stability of the community with an appropriate proportion.In the end,when there are five kinds of interactions in the community,it was found that competition was conducive to the stability of the community with an appropriate proportion,predator-prey was conducive to the stability of the community with an appropriate proportion,mutualism was conducive to the stability of the community with an appropriate proportion.In the small world network structure,only five interactions are considered.It found that mutualism or competition with an appropriate proportion is conducive to the stability of the community,and predator-prey is conducive to the stability of the community.Through the study,some conclusions are different from the previous conclusions under the assumption that the population density is equal.Generally,the appropriate combination of interaction types increases the complexity of the community and which is conducive to community stability,it reflects the fact that the diversity of interaction types is one of the reasons for maintaining the stability of communities with all kinds of species,which enriches the previous studies.