My research interests
I am an ecosystem ecologist and biogeochemist. My work integrates several disciplines to improve our understanding of water quality and quantity in our changing agricultural landscapes.
The top meter of the earth’s soil contains about twice the amount of carbon than the atmosphere. Agricultural management practices influence whether a cropland soil is a net carbon source or sink. These practices affect both organic and inorganic carbon cycling. although the vast majority of soil carbon studies examine the former. For my PhD, I've tracked inorganic carbon cycling in agricultural soils via liming and groundwater-fed irrigation. Crushed limestone (CaCO3) acts like an antacid for the soil, which is acidified by nitrogen fertilizer. Previous work estimated that CO2 emissions from liming accounted for about one quarter of the total global warming impact (GWI) from no-till systems. My measurements are important for understanding how much of this lime- and irrigation-derived carbon actually contributes carbon dioxide to the atmosphere and how much sequesters additional carbon in the soil and groundwater.
To complement the above inorganic carbon study, I've also measured dissolved greenhouse gases emitted from groundwater used for irrigation, dissolved organic carbon (DOC) leaching to groundwater, and carbon and nitrogen storage in soil organic matter. All were compared in a corn-soybean-wheat rotation under no-till management across a nitrogen fertilizer gradient where half of the replicated blocks are irrigated with groundwater. These studies were conducted at the Kellogg Biological Station Long Term Ecological Research site in Michigan.
I've also conducted focus groups with corn-soybean irrigators in southwest Michigan to better understand their management decision making process. The amounts they reported for irrigation, lime, and fertilizer will be used to scale up my findings to the watershed scale.
My research in 2.5 minutes. This video is from 2014, so a few years old but still gives you an idea of my research. I originally made it for the NSF GK-12 program at the Kellogg Biological Station. Filming and editing by Lucas Hamilton.
From Sept. 2016 - March 2017, I worked in Botswana through a collaboration with the International Water Management Institute’s Southern Africa office and a USAID Borlaug Fellowship. There, I studied an important source of drinking water, an aquifer, that was contaminated with nitrate. I was able to demonstrate that human waste is contributing to the nitrate pollution by measuring caffeine in the groundwater. I also found that there is potential for bioremediation to help “treat” the nitrate in the groundwater by taking advantage of microbial denitrification, which I demonstrated is already underway in the aquifer. In the big picture, climate change, droughts, and infrastructure limitations are driving people to rely more on pit latrines (a major source of human waste) than flush toilets due to infrastructure limitations and water shut offs due to droughts and climate change. (Manuscript submitted to Hydrogeology Journal.)
Prior research/professional experience
Wright Lab manager, Duke University, Durham NC. Community ecology field and lab research with Dr. Justin Wright. Sept 2007 - August 2012.
Participated in writing articles, presented research at professional meetings, mentored undergraduate student research, managed lab assistants
Farmhand, Fickle Creek Farm, Efland, NC. Part time work at a small, sustainable produce and livestock farm. July 2010 - July 2011.
Plant Ecology Research Assistant, Commonwealth of Dominica, West Indies and Lab Technician, Clemson University, South Carolina. Tropical plant ecology and invasive plant ecology and genetics with Dr. Saara DeWalt. June 2006 - Aug 2007.
National Science Foundation Research Experience for Undergraduates, Flathead Lake Biological Station, University of Montana, near Polson, Montana. Summer 2005. Through this internship I worked with Dr. Ric Hauer (U. of Montana) and Dr. Emily Bernhardt (Duke University) to develop a research project investigating the nutrient limitation of periphyton in the Nyack Floodplain of the Middle Fork of the Flathead River, comparing between upwelling and downwelling sites. I was also the field assistant to Dr. Brian Reid, then Ph.D. student of Dr. Hauer’s.
Internship at Omar Torrejos National Park, El Cope, Cocle, Panama & Fortuna Forest Reserve, Chiriqui, Panama. Summer 2004. Worked with Ph. D. student from Institute of Ecology at the Univ. of Georgia on his research investigating ecosystem-level effects of tadpoles on tropical mountain streams; part of a larger NSF-funded study, “Collaborative Research: Response of Tropical Stream Ecosystem Structure and Function to Amphibian Extinctions,” involving PI’s from Drexel University and Southern Illinois University at Carbondale.