DISSERTATION RESEARCH: Does grazing stimulate root exudation and accumulation of soil carbon in perennial grasslands?

University Of Florida, Gainesville FL

Investigators

Abstract

The goal of this project is to identify factors that regulate the uptake and storage of carbon within soils of cattle pastures in the southeastern United States. Carbon molecules that have been isotopically labeled will be tracked and used to answer questions about how and where carbon is sequestered by plant roots and soil microbes. The two main questions that will be addressed are: how plants transfer internal carbon from roots to the soil, and how microbes in the soil determine whether that carbon is quickly released back to the atmosphere through respiration or stabilized and stored for long periods of time? Carbon stored in soils for long periods of time is critical for the functioning of healthy ecosystems, in this case important agricultural systems in the US, but is also of interest for managers and policy makers because it represents the strength of the ecosystem for storing carbon from the atmosphere. One promising strategy to at least help offset carbon emissions from human activities is to strengthen the uptake and storage capacity for carbon in the soils of grasslands, since they are globally extensive and also vital for agricultural production. This project will advance technical understanding of the processes that regulate grassland soil carbon storage. Additional outcomes include graduate student training, opportunities for collaboration across scientific disciplines, mentoring and education of undergraduate students, and the extension of results to help farm managers understand and increase their abilities to store carbon on-farm while also improving pasture sustainability.