Faculty of the Ecology group (Bertness, Hamburg, Sala, Waage and Witman) have diverse but overlapping research interests centered around the following broad themes:

Testing effects of upwelling and predation on barnacle recruitment in Galapagos

Ecology of food webs

The science of ecology began with food web dynamics, yet we still do not know to what extent highly connected food webs can be reduced to a small number of strong interactions. Recent work by marine ecologists in our group has revealed that herbivores and their carnivores (top-down forces), rather than energy and nutrient flow (bottom-up forces), control the food-web dynamics of salt marshes. Studies of food web regulation by bottom-up and top-down forces, and multiple predator effects, are ongoing in salt marshes, intertidal and rocky subtidal communities. An emerging theme in our group is to understand how microbes mediate trophic interactions. At landscape spatial scales, we wish to know how the movement of nutrients and consumers between adjacent ecosystems affects food web and community dynamics in the recipient ecosystem.

Function and patterns of biological diversity

Explaining variation in biodiversity, how it is maintained and its significance for the functioning of communities and ecosystems is a major focus of several research faculty. Working largely in coastal ecosystems, we are investigating the influence of environmental stress gradients on plant diversity, patterns and function of microbial diversity at multiple trophic levels, and the effects of regional and local processes on marine invertebrate diversity. The results of this work contribute to developing ecological theory on the role of positive interactions, productivity and regional species pools as they affect the origin and maintenance of diversity.

Anthropogenic influences on ecosystems

Flats for fertilizer experiments

Mindful of how rapidly humans have altered natural ecosystems, ecologists in our group have taken a comparative historical and manipulative experimental approach to discern the nature and extent of human impacts. We want to know how patterns of past human disturbance and species removal dictate the present dynamics of ecosystems and marine food webs. Complementary research on critical habitats, population dynamics, ecological engineers, and trophic interactions permit us to recommend strategies that minimize anthropogenic impacts on biodiversity and ecosystem function.

Gull exclusion cages on the Isle of Shoals

Macroecology

We are documenting patterns of species distribution, diversity and interaction that emerge when intertidal and subtidal communities are viewed on the largest spatial scales, and investigating the processes driving these patterns. We are particularly interested in how physical factors regulate biotic interactions along latitudinal gradients and how oceanographic processes connect local communities on large spatial scales. Scaling up these insights about community regulation to a global spatial scale involves the ecology group in the emerging interdisciplinary program in Global Change Biology.

Foraging ecology

Using insects and spiders as model systems, researchers in this group investigate how foragers select resources and the different consequences of foraging decisions for the lifetime fitness of foragers. The pronounced sexual dimorphism and skewed sex ratios of some groups like spiders take on particular interest as they affect patch choice, shape demography and ultimately fitness. How foragers are constrained by harsh environmental conditions interests both terrestrial and marine ecologists in the group.

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