The widespread clearing and subsequent fragmentation of terrestrial ecosystems is widely acknowledged as a major cause of the decline of biodiversity. However, the specific mechanisms involved and what conservation practitioners can do to ameliorate this decline are not so clear. Predictions have been made from theory and empirical studies have confirmed many of those predictions. At the same time, those studies have identified flaws in theory and provided new insights into the effects of fragmentation, including the role played by the matrix surrounding fragments, the importance of edge effects, and the impacts of corridors linking fragments with one another. A cornerstone of this research is the idea that it is relevant to conservation and management. However, the question remains: How have theoretical and empirical insights influenced conservation and management in fragmented landscapes? To address this question we: 1) reviewed lessons learned from large-scale fragmentation experiments, 2) highlighted strengths of observational studies for providing additional lessons, and 3) surveyed conservation experts to assess links and mismatches between ecological studies and conservation practice.
Results/Conclusions
Lessons for conservation of fragmented landscapes that emerged from our review were 1) the conservation value of small fragments, 2) prevalence of effects on ecosystem processes, 3) importance of the matrix, 4) extent of evidence for corridor efficacy, 5) species-specific responses, 6) importance of temporal effects, 7) identification of drivers that occur across broad scales, 8) effects of fragmentation on ecosystem services, and 9) benefits of management/restoration practices. Our survey results indicate that 1) respondents think fragmentation is a chief threat to biodiversity/ecosystems, 2) fragmentation experiments are useful for conservation, 3) general lessons above are important, but 4) specific experiments are largely unfamiliar and of limited usefulness. The latter is surprising given these experiments’ key role in the conservation lesson above and the importance of these lessons to respondents. We postulate that while the lessons learned may have become conventional wisdom, studies from which they come are unfamiliar. In sum, we argue that fragmentation studies have made important contributions to conservation by deepening our ecological understanding of fragmentation. However, there are key disconnects between what is being studied and conservation imperatives, namely, community-based human dimensions, policy and governance, ecosystem services, eco-evolutionary dynamics, and interaction of multiple stressors.