Conflicts between biodiversity representation and persistence in spatial networks

Background/Question/Methods

A goal of conservation biology is to effectively maintain biodiversity on a landscape as habitat is lost.  Often, conservation attention is focused on maximizing biodiversity representation in protected areas by choosing patches with biotas that complement each other.  However, the deconstruction of dispersal networks has potential negative effects on biodiversity persistence in remaining areas, and these effects may not be independent of the biodiversity patterns used for conservation prioritization.  Metacommunity theory offers one route to understanding the connection between the biodiversity pattern observed across a landscape and the importance of each patch for biodiversity persistence.  Here I use spatially-explicit neutral metacommunity theory to evaluate these effects in landscapes with complex network structure.

Results/Conclusions

I show that biodiversity representation and persistence are in conflict when biodiversity patterns are generated by dispersal limitation and not environmental gradients.  More isolated patches develop uniqueness and are thus more important for representation, but are less important for persistence in other patches.  High connectivity patches appear redundant but are most important for maintaining diversity across the metacommunity. The result of this tradeoff is that when biodiversity patterns are driven by dispersal limitation, the effects of removing a patch on metacommunity diversity are independent of measures of conservation value based on biodiversity patterns.