Controls on C and nutrient cycling across continental gradients
The focus of much of our research is on studying the basic patterns and underlying mechanisms of carbon and nutrient cycling, loss, and retention in terrestrial and aquatic ecosystems. Understanding the controls of these fundamental processes is essential to predicting the response of ecosystems to a changing world. By looking across a range of natural waters, soils, and sediments, we can better discriminate broad controls on C and nutrient cycling.
Ecosystem-level impacts of chemical perturbations
Human-caused global change goes beyond greenhouse gas emissions and global climate change. The wastes and byproducts of humans and our activities are increasingly entering ecosystems where they can serve as both resources and stressors to plants, algae, and microbes. Much of our work is dedicated to understanding the impacts of these chemical perturbations on ecosystem function.
Ecosystem impacts of engineered nanomaterials
One such project studies the impacts of an emerging class of contaminants, engineered nanomaterials, on the ecosystems. This work represents a collaboration with many investigators at Duke, University of Kentucky, Stanford, Carnegie Mellon, Virginia Tech, Howard, UNC Chapel Hill, and Clemson. Our investigations have ranged from small lab scale assays to field scale terrestrial and aquatic mesocosms, and we have seen alterations from the level of organisms to ecosystems at environmentally relevant concentrations of nanoparticle pollution.
We have also focused on understanding the impacts of saltwater intrusion into dominantly freshwater coastal wetlands. In collaboration with Emily Bernhardt at Duke, Marcelo Ardón at Eastern Carolina University, and Jen Morse at Portland State University, we have looked to see how saltwater intrusion affects trace gas emissions and nutrient retention and release in soils within formerly freshwater coastal wetlands.