Metapopulation capacity determines food chain length in fragmented landscapes

Shaopeng Wang (1) , Ulrich Brose (2, 3) , Saskya van Nouhuys (4, 5) , Robert Holt (6) , Michel Loreau (7)

1 Peking University [Beijing]
2 Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany]
3 iDiv - German Centre for Integrative Biodiversity Research
4 Helsingin yliopisto = Helsingfors universitet = University of Helsinki
5 Cornell University [New York]
6 UF - University of Florida [Gainesville]
7 SETE - Station d'Ecologie Théorique et Expérimentale

Metapopulation capacity provides an analytic tool to quantify the impact of landscape configuration on metapopulation persistence, which has proven powerful in biological conservation. Yet surprisingly few efforts have been made to apply this approach to multispecies systems. Here, we extend metapopulation capacity theory to predict the persistence of trophically interacting species. Our results demonstrate that metapopulation capacity could be used to predict the persistence of trophic systems such as prey–predator pairs and food chains in fragmented landscapes. In particular, we derive explicit predictions for food chain length as a function of metapopulation capacity, top-down control, and population dynamical parameters. Under certain assumptions, we show that the fraction of empty patches for the basal species provides a useful indicator to predict the length of food chains that a fragmented landscape can support and confirm this prediction for a host–parasitoid interaction. We further show that the impact of habitat changes on biodiversity can be predicted from changes in metapopulation capacity or approximately by changes in the fraction of empty patches. Our study provides an important step toward a spatially explicit theory of trophic metacommunities and a useful tool for predicting their responses to habitat changes.

Mots clés: trophic interactions; heterogeneous landscapes; habitatchanges; fragmentation

Domaines: Sciences de l'environnement

Shaopeng Wang, Ulrich Brose, Saskya van Nouhuys, Robert Holt, Michel Loreau. Metapopulation capacity determines food chain length in fragmented landscapes. Proceedings of the National Academy of Sciences of the United States of America, 2021, 118 (34), pp.e2102733118. ⟨10.1073/pnas.2102733118⟩. ⟨hal-03384639⟩