First Advisor
Jennifer L. Morse
Date of Award
Spring 6-12-2026
Document Type
Thesis
Degree Name
Bachelor of Science (B.S.) in Environmental Science and University Honors
Department
Environmental Science and Management
Language
English
Subjects
Wetland Restoration, Greenhouse Gas Fluxes, Soil Biogeochemistry, Coastal Wetland, Freshwater Wetland, Climate Change
Abstract
Wetlands provide valuable ecosystem services, one of which is a wetlands ability to sequester carbon. Climate change and human land use threaten a wetlands ability to do so. Globally, 21% of wetlands have been lost since the 1700s. As a result, restoration of wetlands has been increasing. However, wetlands in the process of restoration emit more methane than degraded ones, and as the climate continues to change, these fluxes could respond. Projected sea level rise is expected to cause salt water to infiltrate coastal freshwater systems, increasing the salinity. Past research has found that increased salinity has led to suppressed CH₄ and N₂O emissions, but increased CO₂ emissions. Additionally, increasing global temperatures are expected to increase N₂O and CH₄ emissions. Understanding how salinity and temperature increases impact GHG cycling in restored freshwater wetlands individually and together is important to predicting the ecosystem’s response to climate change. This was a lab-based study paired with an ongoing field experiment that investigated how salinity and temperature increases impact the cycles of N₂O , CH₄, and CO₂ in a coastal freshwater wetland that was hydrologically restored in 2017. There were no significant interactions between salinity and temperature impacting GHG cycling, however individually they both had significant effects. Salinity suppressed CH₄ emissions and increased N₂O emissions, and temperature was found to suppress N₂O emissions. Results from this study were conflicting with past field research, but aligned with some previous lab studies, suggesting the need for more lab and field paired designs.
Recommended Citation
Hendrickson, Annika, "Projected Climate Change Impacts on Soil Greenhouse Gas Emissions from a Restored Freshwater Marsh" (2026). University Honors Theses. Paper 1892.