Wetland Hydro-biogeochemistry
The unique hydrological conditions of wetland landscapes alter their biogeochemistry in a manner that they behave as carbon sinks, i.e., they gain organic carbon over time. Understanding and quantifying these natural processes and the effects of anthropogenic disturbances to these systems, including extreme episodic flooding and extended periods of drought, are necessary to predict accurately the important role of wetlands to regional and global carbon cycling and climate change.
- Role of organic compounds on contaminant transport.
- Riparian wetlands in the Southeast have high organic matter concentrations and their streams are often naturally brown (referred to as black water streams) due to elevated natural organic matter concentrations. These organic molecules can bind contaminants and transport them downstream. Our group conducts research to identify the binding environment of radionuclides and trace metals to natural organic matter in streams and in wetland soils and how changes in hydrological conditions impact these key processes.
Impact of iron- and sulfur-cycling on organic carbon balance in wetlands.
Another focus of our lab is to understand the role of fluctuating hydrological conditions in wetlands on carbon greenhouse gases. Particular attention is directed at relaying these hydrological conditions on iron and sulfur cycling. We probe these questions at multiple scales, including in the lab (mm scale), meso-scale (m scale) and watershed scale (km scale). Several advance characterization techniques are applied to probe these various scales, including computer-tomography, synchrotron X-ray absorption, and numerous mass spectroscopy and coupled mass spectroscopy techniques. Typically, these studies culminate in a numerical chemical model or reaction transport model describing the movement of the contaminant in the environment.