Speaker
Description
Although the negative effects of habitat loss on biodiversity are arguably well understood, there is active debate regarding the isolated effects of fragmentation per-se. While the empirical literature suggests a variety of effects of fragmentation on biodiversity, there are few theoretical frameworks for understanding when divergent responses should be expected. Here we show how assumptions regarding the stability of local population dynamics influence emergent biodiversity patterns in landscapes across gradients of habitat loss and fragmentation. We take a theoretical approach and simulate spatially explicit metacommunities with a model that allows for variable population dynamics which can be either locally-stable (i.e., persistent) or locally-unstable (i.e., transiently bound for extinction). Our results show that metacommunities with locally-stable population dynamics all exhibit similar responses to habitat loss and fragmentation regardless of the details of their population dynamics (e.g., fixed point, periodic oscillations, or aperiodic oscillations). Furthermore, we find that these locally-stable metacommunities can exhibit a range of responses to habitat loss ranging from negative to hump-shaped, depending strongly on the degree of fragmentation. This is in contrast to locally-unstable metacommunities which exhibit consistently negative responses to habitat loss regardless of the degree of fragmentation. Isolating this effect of fragmentation, we show that when habitat loss is high our model predicts contrasting effects on biodiversity, where locally-stable metacommunities respond positively and locally-unstable metacommunities respond negatively. This work provides a mechanistic exploration of how local population dynamics can influence large-scale biodiversity patterns in fragmented landscapes and provides predictions as to when and why contrasting responses should be expected.
| Status Group | Postdoctoral Researcher |
|---|---|
| FOR TALKS: Poster Presentation Option | Undecided/No preference |