The role of omnivory in mediating metacommunity robustness to habitat destruction

Abstract

Citation: Liao, J., D. Bearup, and W. F. Fagan. 2020. The role of omnivory in mediating metacommunity robustness to habitat destruction. Ecology 101(6):Abstract. Omnivores have long been known to play an important role in determining the stability of ecological communities. Recent theoretical studies have suggested that they may also increase the resilience of their communities to habitat destruction, one of the major drivers of species extinctions globally. However, these outcomes were obtained for minimal food webs consisting of only a single omnivore and its prey species, while much more complex communities can be anticipated in nature. In this study, we undertake a systematic comparative analysis of the robustness of metacommunities containing various omnivory structures to habitat loss and fragmentation using a mathematical model. We observe that, in general, omnivores are better able to survive facing habitat destruction than specialist predators of similar trophic level. However, the community as a whole does not always benefit from the presence of omnivores, as they may drive their intraguild prey to extinction. We also analyze the frequency with which these modules occur in a set of empirical food webs, and demonstrate that variation in their rate of occurrence is consistent with our model predictions. Our findings demonstrate the importance of considering the complete food web in which an omnivore is embedded, suggesting that future study should focus on more holistic community analysis.

Invasive spread in meta‐food‐webs depends on landscape structure, fertilization and species characteristics

“…1b). By affecting species persistence and species diversity (Hiebeler 2000, Liao et al 2013a, b2013b, 2016, 2017a, b2017b, 2020), the configuration of habitat can affect also the ‘invasibility' of the native community (i.e. more diverse native communities should be more resistant to invasions: diversity–invasibility hypothesis; Elton 1958).…”

Network topology and patch connectivity affect dynamics in experimental and model metapopulations

“…For occupancy, we were able to mirror our experimental results with simulations by tuning the extinction function in our model. Previous studies (Gilarranz & Bascompte, 2012;Liao et al, 2020) showed that occupancy patterns in networks with different degrees of heterogeneity can vary with extinction rates. They demonstrated that in scenarios of low extinction/ colonization, random networks will have higher occupancy than scale-free networks, a trend that is reversed as extinction probability increases.…”

Metacommunity framework and its core terms entanglement

“…A general approach to MC structure and dynamics requires that it accommodates its most recognized feature -competition cf. (Leibold et al 2004;Logue et al 2011;Thompson et al 2020), other direct interactions such as predation (Abrams 2007;Jabot & Bascompte 2012;Ryberg et al 2012;Vanschoenwinkel et al 2013;Haegeman & Loreau 2014;Liao et al 2020), mutualism (Yu et al 2004), parasitism, commensalism as well as a high number of possible indirect interactions (e.g., Miller & Kneitel 2005;Gravel et al 2010;Miller & terHorst 2012).…”