Two UGA graduate students receive National Science Foundation Graduate Research Fellowships

Two graduate students from the University of Georgia have received Graduate Research Fellowships from the National Science Foundation this year. This award recognizes and supports outstanding early career graduate students in NSF-supported science, technology, engineering, and mathematics disciplines who are pursuing research-based master’s and doctoral degrees.


The 2018 NSF Graduate Research Fellowship recipients are Callie Oldfield and Jeremy Schreier.


Callie Ashton Oldfield, a doctoral student in the Department of Plant Biology, researches the impacts of tornadoes on the carbon storage of forests. Forests store a vast amount of carbon in the soil, forest floor, and both dead and live trees. When a forest is damaged by a tornado, the carbon cycle is altered as a result of tree and soil disturbance.


Oldfield’s measurements of forest carbon storage after a tornado will be used to model the amount of time it takes for a tornado-damaged forest to return to the same levels of carbon storage it had before the tornado.


“Preliminary results suggest that soil respiration [carbon release from soil to atmosphere] is significantly elevated during warm months, even seven years after a tornado. I hope to understand the effects of tornado severity on forest recovery as I collect more data over the course of my graduate study,” says Oldfield.


Jeremy Ethan Schreier, a doctoral student in the Department of Marine Sciences, studies microbial communities in the sunlit (euphotic) zone of the ocean environment. These microbial ecosystems contain diverse organisms connected by the exchange of metabolites (substances formed in or necessary for metabolism).


One of the most well-studied microhabitats in the euphotic zone is the phycosphere, the metabolite and nutrient rich area of organic matter surrounding a phytoplankton cell. These phytoplankton release a wealth of organic molecules, which bacteria are then able to utilize for growth. Bacteria are able to breakdown and release this organic matter in its simplest inorganic forms, in turn supporting phytoplankton growth and production.


Schreier’s current project aims to understand the genetic basis of microbial success during the assembly of phycosphere communities.


“The experimental strategy is to assess the fitness advantage conferred by an individual gene during growth in phycospheres by measuring the ecological success of bacteria when that gene is rendered non-functional,” he explains.


As the oldest fellowship of its kind, the Graduate Research Fellowship Program (GRFP) has a long history of selecting recipients who achieve high levels of success in their future academic and professional careers. NSF Fellows are anticipated to become knowledge experts who can contribute significantly to research, teaching, and innovations in science and engineering.  The 2019 GRFP application period is now open for undergraduate seniors and first time applications from graduate students.  More information can be found at