Incorporating Positive Interactions in Aquatic Restoration and Conservation

Benjamin S. Halpern, Brian R. Silliman, Julian D. Olden, John P. Bruno, and Mark D. Bertness. 2007. Incorporating positive interactions in aquatic restoration and conservation. Frontiers in Ecology and the Environment 5: 153–160.

Negative interactions (competition, predation) commonly dominate ecological research over much of past century. This paper discusses the role of positive interactions in restoration and conservation, with a focus on aquatic environments. The authors clearly link the type of positive interaction; with where/when it important for restoration and conservation and with implications for the practice of restoration and conservation. The broad categories covered include: traditional interactions (facilitation, foundation species, mutualisms, succession), within-population interactions (Allee effects, density-dependent recruitment), and large scale interactions (resource subsidies between ecosystems, ontogenetic habitat shifts, protection of neighboring ecosystems). The authors conclude that two key interactions to consider in management plans include: (1) foundational species population size in order to avoid Allee effects and (2) spatial arrangement of different ecosystems and connections among those systems.

As a restoration practioner and land manager, I found the author’s approach to directly link ecological theory to on the ground restoration practice refreshing. I could clearly see what types of interactions should be considered in restoration planning. However, the authors acknowledge that it is not possible to prescribe how best to incorporate positive interactions across management plans. In addition, little is known between trade-offs and consequences between different types of interactions. For this reason it is crucial for managers to understand that the importance of different positive interactions is context dependent.