- John Gardner is a PhD student with Martin Doyle and is broadly interested in ecosystem ecology, biogeochemistry, geomorphology, and hydrology. His research explores the role of the water column in rivers. This involves connecting the shape of rivers and streams to ecosystem function at various spatial scales, observing rivers from different reference frames (moving vs. stationary), and examining how water and matter move through river channels. John received his BS and BA in Environmental Science and Geography from the University of Missouri in 2010. He then worked as the Greenway Ranger for the City of Knoxville/AmeriCorps. In 2014, John received a MS degree from the University of Maryland Center for Environmental Sciences focusing on denitrification, N2O production, and nutrient export in headwater streams.