Robustness of metacommunities with omnivory to habitat destruction: disentangling patch fragmentation from patch loss
Abstract
Habitat destruction, characterized by patch loss and fragmentation, is a major driving force of species extinction, and understanding its mechanisms has become a central issue in biodiversity conservation. Numerous studies have explored the effect of patch loss on food web dynamics, but ignored the critical role of patch fragmentation. Here we develop an extended patch-dynamic model for a tri-trophic omnivory system with trophic-dependent dispersal in fragmented landscapes. We found that species display different vulnerabilities to both patch loss and fragmentation, depending on their dispersal range and trophic position. The resulting trophic structure varies depending on the degree of habitat loss and fragmentation, due to a tradeoff between bottom-up control on omnivores (dominated by patch loss) and dispersal limitation on intermediate consumers (dominated by patch fragmentation). Overall, we find that omnivory increases system robustness to habitat destruction relative to a simple food chain.
- Publication:
-
Ecology
- Pub Date:
- June 2017
- DOI:
- Bibcode:
- 2017Ecol...98.1631L
- Keywords:
-
- bottom-up control;
- food chain;
- food web robustness;
- landscape fragmentation;
- omnivory;
- patch connectivity;
- patch-dynamic model;
- patch loss;
- species dispersal;
- top-down control