Collaborative Research: the influence of predators on community structure and resultant ecosystem functioning at a biogeographic scale

Predators structure ecological communities by consuming and altering the traits of prey, yet these effects have only recently been linked to local variation in ecosystem functions such as primary production and nutrient cycling. Such linkages may operate differently across biogeographic scales because factors known to affect local predator mechanisms also vary with latitude. The mismatch between knowledge of how predators locally affect ecosystem functions and the biogeographic range at which predator-prey interactions occur inhibits understanding of linkages between ecological communities and ecosystems, and thus our ability to manage valuable ecosystem services. Intertidal oyster reefs provide a model system to address this knowledge gap: they occur throughout the mid-Atlantic and Gulf coasts; they contain a similar food-web assemblage across latitudinal gradients in predation, resource supplies, and environmental conditions; they are strongly influenced by predator effects; and they influence sediment and nutrient cycles by enhancing benthic-pelagic coupling. This research involves a series of standardized sampling and experimental studies to: (1) investigate biogeographic patterns in oyster food web structure, resource supplies, environmental conditions, and sediment properties associated with reef function (2) determine how the vital rates of oysters, which can influence benthic-pelagic coupling, vary geographically; and (3) examine experimentally the relative importance of consumptive and non-consumptive predator effects on oyster reef communities and the ecosystem processes they provide and how these effects vary latitudinally. It will provide a mechanistic understanding of the basis for biogeographical shifts in valuable ecosystem services performed by an important marine foundation species, and it will also advance understanding of the interactions between predator effects in food webs and the ecosystem processes that depend on them.

By linking predator effects and benthic-pelagic coupling on oyster reefs in a biogeographic context, this research will provide valuable information to resource managers charged with restoring oyster reefs and recovering ecosystem services. By promoting the exchange of conceptual and methodological ideas among research groups at four major research universities, this project has already and will continue to foster interdisciplinary expertise among its investigators as well as their future graduate and undergraduate students. In addition to mentoring a post-doc, this research will prepare at least three graduate and three undergraduate students for scientific careers by having them independently develop projects related to the project. The investigators are committed to mentoring a diverse group of students across multiple educational levels, and they will continue to disseminate results to the public through lectures, open house events at their respective institutions, as well as radio, newspaper, and television interviews.