Snail feeding on barnacles

Ecology | Evolution | Morphology | Current Postdoctoral Researchers

Faculty of the Ecology group (Bertness, Leslie, Porder, Rich, Sax, Schmitt, Smith, and Witman) have complementary and diverse research interests centered around the following themes:

Ecosystems and global change

It is increasingly clear that no ecosystems are free from human influence; our research foci are emblematic of the myriad ways in which humans are changing the planet. We work in coastal regions from New England to Argentina to understand how community dynamics (from fish to plants to microbes) respond to human activities. Field studies in marine systems from New England to Alaska and the Galapagos increase our understanding of how fisheries management and other coastal and marine activities influence wild populations and the future of fishing-based communities. We also have active research across tropical and temperate forests, exploring both natural and anthropogenic drivers of biotic and biogeochemical variation. In addition to having globally distributed research sites, we are asking global questions: how and why do species extinctions occur, and how will species distributions shift with the  changing climate? How do vectors of infectious disease change as we move people, animals and plants around the world at unprecedented rates? And how can we maintain the ecosystem services upon which we all depend in the face of a growing population and increasing demands for energy, food, land, and water?

Tropical rainforest in Brazil are being cleared at unprecedented rates.  Unlike decades past, much of the land in Mato Grosso State (shown here) is now being converted to intensive agricultural production.  We are interested in the effects of this conversion on local, regional, and global biogeochemistry.

Biological diversity

We focus on past and future variation in biodiversity, and its significance for the functioning of biological communities and ecosystems. We work at the global scale, but also focus regionally on marine, coastal and arid ecosystems. For example, how do species invasions influence biological diversity? Are salt marsh plant communities structured primarily by abiotic stress gradients or foraging of herbivores, and what are the implications of this understanding for management and restoration? How can we integrate knowledge of ecosystem structure and functioning to sustain fish populations and other marine ecosystem services in a world of hungry human consumers? What are the future scenarios of biodiversity change in different parts of the world, and the implications of these changes for human well-being? The results of this work contribute to developing ecological theory on the role of predators, positive interactions, productivity and regional species pools in the origin and maintenance of biological diversity.

Scene from an experiment measuring the effects of consumers on key benthic invertebrates (barnacles, sea urchins) in the Galapagos Marine Reserve. Orange fish at left is harlequin wrasse, a major predator.

Diverse community of epifaunal invertebrates on a subtidal rock wall in the Galapagos Marine Reserve. (Photo credit: A. Irving)

Community Ecology

Our group explores how biotic and abiotic interactions combine to shape biological communities on land and in the sea. One major focus is understanding the importance of consumer control of ecosystem properties and the hierarchical organization of communities. Another is how community structuring processes vary with temporal and spatial scale. Finally, we work to integrate scientific information into policy through complementary communication and translation activities from the regional to the international scale.

Fisheries in Mexico's Gulf of California (above) have been severely impacted by overfishing, coastal development, and water diversion. Using a combination of modeling and empirical approaches, we are investigating how human-environment interactions influence both ecosystem health and human well-being. The results of this work are relevant to the growing interest in the region (and elsewhere) in more ecosystem-based approaches to coastal and marine management.

Recreational fishing infrastructure provides fishing pressure that can trigger trophic cascades in New England benthic communities.

Former graduate student Brian Silliman (now at U. Florida) uses the unorthodox quadrat method to count cows.

Biogeochemistry

We are focused on the cycling of energy and matter at a variety of spatial scales - from microbes to the globe. We study biogeochemical phenomena at different temporal scales from tectonic effects on nutrient availability to interannual variability in precipitation and its effects on the carbon cycle. We are particularly interested in the cycling of carbon, nitrogen and phosphorus, and nutrient limitation to primary production on land and in the oceans. In particular, we have expertise in the biogeochemistry of tropical rainforests, grasslands, oceans and estuaries. We also explore the human impacts on biogeochemical cycling - from issues of coastal eutrophication to the role and fate of fertilizer applied to our ever more intensively farmed agricultural fields.

Deforestation in the mountains of southern Costa Rica brings dramatic changes to carbon and nutrient stocks in soils - changes we document with a lot of digging and even more analyses.