MS Thesis Defense
CHEMICAL CHARACTERIZATION OF SOIL ORGANIC MATTER IN A CHESAPEAKE BAY SALT MARSH: ANALYZING MICROBIAL AND VEGETATION INPUTS
Blue carbon ecosystems play an outsized role in the burial and storage of organic matter compared to other ecosystems. Increasing CO2 levels, sea level rise, and increasing temperature have been shown to influence the storage of organic matter in these environments. Changes to the stability of organic carbon stocks in these systems could have potentially significant affects to the current climate. For this reason, the stability of organic carbon stocks in these ecosystems must be understood at a deeper level to be able to predict how different environmental stressors will affect their stability. Through the combination of bulk organic matter analyses and biomarker methods, this project characterized the changes that organic matter underwent in a C3 and C4 plant-dominated marsh in the Chesapeake Bay to understand the degradation and stable soil organic matter formation process. Overall, the results support the MEMS framework that states soil organic matter is formed mainly through microbial degradation products that create stable organo-mineral complexes with the mineral soil fraction that resist degradation. The top section of each core shows a large decrease in labile materials coupled with indicators of microbial processing of organic matter. Overall, the formation of stable soil organic matter in this study was determined by the ecosystem properties instead of the initial input of organic matter.