My research interests include wetland biogeochemistry, global carbon and nutrient cycling, and impacts of climate change on these cycles.
Coastal wetlands store immense amounts of carbon (C) in vegetation and sediments given their relatively low global area coverage, making them a vital part of the global C cycle. However, freshwater diversion as part of current water management operations and accelerated sea level rise as a result of a warming climate will affect C storage in coastal wetlands, but we are uncertain how. Saltwater intrusion will bring water with ions (e.g. Cl–, SO42-) and metabolic stressors (e.g. sulfides) into historically freshwater wetlands. In oligotrophic wetlands such as the Everglades in the southeastern USA, saltwater intrusion causing increased brackish groundwater discharge will also bring excess phosphorus (P), a limiting nutrient for ecosystem productivity. Saltwater can stress plants and change microbial respiratory processes, leading to a net imbalance in the soil carbon cycle and potentially peat collapse. The objective of this study will be to investigate how simulated saltwater intrusion into a freshwater and brackish Everglades marsh affects peat collapse through changes in net ecosystem productivity and soil C pools. I will examine how plant gross primary production, plant respiration, ecosystem respiration, and net ecosystem exchange in coastal wetlands will change when exposed to saltwater and an increase in P loading. Results from this study will reveal how the soil C balance in freshwater and brackish wetlands changes with saltwater intrusion as a result of sea level rise. The results will be crucial for managing and predicting future coastal peat stability to inform coastal water management best practices and adaptive strategies along the entire coast of Florida.
2. Carbon dioxide, methane, and sediment biogeochemistry from Alabama’s coastal marshes
Alabama has a diverse array of coastal marshes despite its relatively low amount of coastline. However, these wetlands have been lost at astonishingly high rates over the past centuries as a result of water channel manipulation, anthropogenic encroachment, and natural subsidence. Now, given current and future climate change, these marshes face many more stressors in the near future. Coastal marshes survive by storing carbon and building elevation, but this function is modified by saltwater intrusion. I am interested in the health of the coastal marshes of Alabama, in particular when it comes to their current ability to store carbon. I found that the ability of these marshes to store carbon continue building elevation may already be in danger.