Life Sciences Commons^™

Soil Organic Carbon In Maine, Its Responses To Biochar Addition, And Climate Change, Xue Bai

Electronic Theses and Dissertations

Soil organic carbon (SOC), as one of the largest C pools in terrestrial ecosystems, plays a key role in governing soil ecosystem processes and climate regulation. Climate change concerns have resulted in a rapidly growing interest in understanding the potential for natural climate solutions (NCS) that include enhancing SOC sequestration and reduce net atmospheric greenhouse gas (GHG) emissions. This research focused on addressing information needs about SOC in Maine, specifically in evaluating available soil databases to accurately quantify SOC density and concentration, and study the response of selected representative Maine soils to biochar amendments under a changing climate.

Maine SOC …

Microbial Community Responses To Salinification: Applications In Climate Change And Extreme Environments, Eric Weingarten

Electronic Theses and Dissertations

Sediment microbial community responses to elevated salinity are important in predicting the effects of sea level rise as well as in understanding those communities that can thrive in extreme environments. In this dissertation, I use natural and field experiments to investigate how salinity influences microbiome structure in coastal wetlands. Through the use of amplicon sequencing, I demonstrate that there are compositional differences between the microbiota of four wetland salinity classes: limnetic, oligohaline, mesohaline, and polyhaline. These results were reciprocated in a microcosm study exposing freshwater sediment to meso- and polyhaline conditions, showing that communities shifted proportionally to the magnitude of …