Meta-analysis on a Decade of Testing Corridor Efficacy: What New Have we Learned?
Purpose of Review
Corridors are widely considered as a strategy to mitigate effects of habitat fragmentation on biodiversity. There are, however, lingering concerns about whether corridors work as intended and whether managing for connectivity in fragmented landscapes is even important for biodiversity conservation. In response, numerous manipulative and natural experiments have been conducted to test the effectiveness of corridors. Gilbert-Norton et al. Conserv Biol. 2010;24(3):660-8 (2010) reviewed such studies published between 1985 and 2008 and concluded that corridors are generally effective at increasing inter-patch movement. The authors noted a lack of studies measuring responses at the population and community levels, responses that would better approximate corridor effects on population persistence and aspects of biodiversity. Here I explored what new insights can be gained on corridor effectiveness from studies published in the last decade, particularly with an eye toward insights going beyond effects on inter-patch movement.
Following the same selection criteria as Gilbert-Norton et al. Conserv Biol. 2010;24(3):660-8 (2010), I reviewed studies published between 2008 and 2018 that tested corridor effectiveness by comparing ecological response variables from patches connected and not connected by corridors. Analysis of effect sizes showed that corridors increase response variables, reinforcing earlier conclusions that corridors function as intended. Whereas the previous review mainly included corridor effects on dispersal, recent research shows support for corridor efficacy at a variety of levels of organization, from individuals to communities.
These findings provide further support for the conclusion that efforts spent creating and maintaining corridors are worthwhile for biodiversity conservation.
KeywordsCorridor experiment Habitat fragmentation Conservation Landscape ecology Connectivity Biodiversity
I thank James Watling and Lenore Fahrig for the invitation to write this paper. I thank Nick Haddad, John Orrock, Doug Levey, Melissa Burt, Lars Brudvig, and Rob Fletcher for valuable feedback. I thank Karen Beard and John Stevens for answering my questions and openly sharing data and code from their meta-analysis. I thank the authors of the reviewed studies who provided additional data. I was supported by a Chancellor’s Postdoctoral Fellowship from the University of Colorado while writing this manuscript.
Compliance with Ethical Standards
Conflict of Interest
Julian Resasco declares that he has no conflict of interest.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
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