Metapopulation dynamics override local limits on long-term parasite persistence

摘要: A simple null model, particularly germane to small and vulnerable organisms such as parasites, is that local conditions set a stage upon which larger-scale dynamics play out. Soil moisture strongly influences survival of entomopathogenic nematodes (EPN), in turn drive trophic cascades by protecting vegetation from root-feeding herbivores. In this study, we examine the mechanisms responsible for patchy occurrence an nematode, Heterorhabditis marelatus, California coastal prairie. One hypothesis proposes biotic factors competition natural enemies could regulate EPN populations. We found fungi other EPN, although locally potent, did not explain patterns incidence across sites. Abiotic also have strong effects on persistence, especially free-living stages. Thus, tested large landscape was driven differences soil moisture. Our research uses long-term data nematode combination with landscape- level experiment demonstrate lack correlation between persistence. year-long showed mortality weakly correlated among our study Thirteen years data, however, colonization rates were highly Sites highest persistence experienced rhizosphere colonization, extinction, turnover. As result, concluded metapopulation override limitations short-term abiotic determine parasite-driven cascade.