My research outcomes and future directions
I integrate ecosystem ecology and sociology to inform policy that aims to conserve natural resources and biodiversity in working landscapes. I see the future of conservation science less in parks and more in working lands. Let me show you why that is exciting.
One branch of my research investigates how agricultural lands and watersheds can be managed to promote, rather than degrade, ecosystem services beyond just food production. One key is biodiversity. For example, cover crops (temporal biodiversity) can provide weed control while reducing soil nitrate loss. But science has yet to show how investments in conservation practices such as cover crops improve water quality at the watershed scale. Taxpayers invest in agricultural conservation practices via the Farm Bill, but we have yet to show how those investments are paying off. River nitrate loads are a product of not just biogeochemical processes, but also the changing climate, altered hydrology, human decision making, and political and economic forces. As a David H. Smith Fellow, I am combining nitrate sensor data, conservation mapping via remote sensing, farmer focus groups, and down scaled global circulation models in the SWAT model to understand how conservation practices affect nitrate loads in the Raccoon River and Boone River watersheds in north central Iowa. Both of these watersheds are in the Prairie Pothole Region and the Des Moines River Basin. They contain some of North America's most threatened waterfowl habitat as well as freshwater mussels, the most endangered group in the Midwest. Many households in rural areas of Iowa rely on untreated well water that can also have high nitrate, a threat to human health. I will use the model to tease apart the multiple drivers of these nitrate loads to see how factors like climate change might be swamping out the successes of conservation practices. Ultimately, I hope this work will help inform how conservation investments are prioritized in the Corn Belt. I am collaborating with Amy Burgin and Terry Loecke at the U. of Kansas, W. Dean Hively at USGS, and Awoke Teshager at the U. of Michigan.
Another branch of my research is exploring the feedbacks between groundwater and climate change. At the Kellogg Biological Station Long Term Ecological Research site in southwest Michigan, I calculated the global warming impact (greenhouse gas emissions and sinks) of groundwater fed irrigation by comparing measurements from a 12 year (and counting) experimental cropping system that is no-till with a corn-soybean-winter wheat rotation with and without irrigation. Previous work at the KBS LTER had already calculated the global warming impact of the entire rainfed cropping system (including inputs, fossil fuel use, and resulting soil-atmosphere fluxes). This is the first study that we are aware of that measured dissolved greenhouse gases in the groundwater and accounted for their emissions upon equilibration with the atmosphere. These emissions are currently not accounted for in the IPCC or other greenhouse gas inventory methods. We also measured changes in soil organic carbon, soil nitrous oxide emissions, and additional fossil fuel emissions for pumping. Ultimately, the rainfed systems was a net carbon sequestering system while the irrigated system was a net emission of greenhouse gases. However the global warming impacts, when normalized by yield, were very similar. You can read the full article here. Agricultural intensification, such as irrigation, might be land-sparing, meaning it could protect habitat elsewhere from conversion into cropland, but this is far from resolved in the literature.
I have continued this work now that I am living in the heavily irrigated state of Kansas with a focus on measuring the dissolved greenhouse gases in groundwater. This work is starting to show that improving irrigation efficiency could be a win-win for groundwater conservation and reducing greenhouse gas emissions. Because our ability to measure greenhouse gas emissions is only as good as our inventory, I hope to ultimately develop a method for estimating greenhouse gas emissions from irrigation groundwater de-gassing and further explore the human dimensions of commercial-scale irrigation. I've conducted focus groups with commercial irrigators in southwest Michigan to better understand their management decision making process. This paper is in the works.
In another study dealing with groundwater and climate change, I worked in Botswana for six months through a collaboration with the International Water Management Institute’s Southern Africa office and a USAID Borlaug Fellowship. There, I studied the Ramotswa Aquifer that is an important source of drinking water and contaminated with nitrate. This aquifer is in the headwaters of the Limpopo River Basin, which supports key wildlife habitat including Kruger National Park. My work demonstrated that human waste is contributing to the nitrate pollution by measuring caffeine in the groundwater. A nearly 100 year rainfall record showed that rainfall and days with rain are decreasing significantly in both the wet and dry seasons. Droughts, through the water infrastructure there, made flush toilets inoperable and led more people to use the pit latrines. I conducted key informant interviews to understand how droughts affected sanitation in the community. Pit latrines are the most likely source of human waste contaminating the aquifer. Climate change is turning a water quantity problem into a groundwater quality problem. I also found that there is potential for bioremediation to remove nitrate in the groundwater by taking advantage of microbial denitrification, which I demonstrated is present in the aquifer but limited by organic carbon. Read the full article here.
Research/professional experience prior to grad school
Wright Lab manager, Duke University, Durham NC. Community ecology field and lab research with Dr. Justin Wright. Sept 2007 - August 2012.
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.
Internship at Omar Torrejos National Park, El Cope, Cocle, Panama & Fortuna Forest Reserve, Chiriqui, Panama. Summer 2004.