Research

Coastal ecology is a vital area of research in order to understand and, ultimately, protect some of the planet’s most valuable, productive, and beautiful ecosystems. I specialize in salt marsh ecology and biogeochemistry and work to discern ways that human impacts (such as nutrient loading, sedimentation, and biological invasion) have altered nitrogen cycling in coastal wetlands. Although coastal wetlands are usually nitrogen-limited, human activities have significantly altered global nitrogen cycles through industrial nitrogen fixation and N loads to the coasts have increased worldwide. With collaborators and students, my research addresses ways that increased N loading affects the structure and function of wetland ecosystems. Our recent studies have revealed an unexpected, potential effect of increased inputs of nitrate to coastal salt marshes – stimulation of N2O (nitrous oxide) emissions! N2O is an agent of stratospheric ozone depletion and a potent greenhouse gas (with about 300 times the global warming potential as CO2 over 100 years). This means that pollution of wetlands may stimulate harmful feedbacks on climate change (Moseman-Valtierra et al. 2011). The cycling of nitrogen in wetland sediments is mediated by intricate interactions between plants and diverse microbial communities that coat plant shoots and pack plant rhizospheres (roots and surrounding sediments). Therefore, in order to understand how these consortia respond to environmental shifts, I combine biogeochemical tools (flux chamber measurements, enzymatic assays, isotopic analyses) and molecular techniques (T- RFLP) with ecological experiments in the field and lab. Ultimately, my goal is to identify ways to sustain coastal wetlands in the midst of rapidly expanding human populations and global climate change. I particularly enjoy working with students on this research and encourage those with interests in coastal ecology to contact me.