Metacommunity Robustness To Plant Invasion In Pollinators-plants-consumers Tripartite Networks

Due to the rapid globalization,alien plant invasion has become an important force to threaten ecosystem structure,function and biodiversity.Therefore,exploring the impact of alien plant invasion on ecosystem stability has become one of the significant issues in ecology.Currently,most studies have mainly focused on the effect of alien invasion on community stability at the same trophic level,while ignoring the response of the network complexity of species interaction between different trophic levels to alien invasion.Recent modelling studies have shown that species invasion can alter the stability of metacommunities with bipartite network structure,and the bipartite network complexity have some degree of resistance to invasion.However,how plant invasion alters the stability of complex systems structured in pollination-predation tripartite networks is still lacking.Therefore,by combining metapopulation theory and complex network theory,this study establishes a patch occupancy dynamic model for metacommunity with mutualism-antagonism tripartite network structure.With this model,I explore how a single exotic plant interacting with local communities(i.e.,the sensitivity of local plants to invasive plant,and the trophic interaction between invasive plant and local animals)affects the robustness of metacommunities structured in pollinators-plantsconsumers tripartite networks,and how the structural complexity(network size,connectance,nestedness and modularity)in tripartite networks resists plant invasion.This study shows that if the fraction of local plants that are sensitive to invasion increases,species diversity in metacommunities will decrease.In addition,by fixing the sensitivity ratio of local plants,increasing the generalization level of the invasive plant when interacting with pollinators or consumers can promote metacommunity stability.Moreover,increasing the generalization level of those local plants sensitive to invasion can lead to a more vulnerable metacommunity.By contrast,increasing the specialization level in local sensitive plants can result in a more robust metacommunity.In addition,increasing network size and connectance can enhance the robustness of metacommunity to plant invasion.However,nestedness and modularity have opposite influences on metacommunity stability.Specifically,increasing the nestedness of mutualistic or antagonistic bipartite networks is detrimental to the persistence of local species,while increasing their modularity is conducive to metacommunity robustness.In summary,this study constructs a patch occupancy dynamic model for metacommunities with a mutualism-antagonism tripartite network structure,explores how plant invasion mediates the complexity-stability relationship in pollinatorsplants-consumers tripartite networks,investigates the effects of interaction traits and invasion rules of alien plant on metacommunity diversity,and reveals the importance of conserving local keystone species for resistance to exotic plant invasion.Therefore,this study offers new insights into how plant invasion affects the robustness of metacommunities with multi-trophic interaction modes,and also provides theoretical basis for biodiversity conservation and management in metacommunities subject to plant invasion.