Upland Migration of Coastal Marshes as a Response to Sea Level Rise and Fire Management: Past, Present, and Predicted

<p>Coastal marshes are one of the most productive and intensively used ecosystems in the world. However, they are under threat due to natural and anthropogenic stressors, such as sea level rise (SLR). SLR can cause marshes to drown, converting them to open water. Marshes can respond to SLR through landward migration when suitable habitat is available. My research focuses on the landward migration pattern and mechanisms. I evaluated the historical land cover changes at the Grand Bay National Estuarine Research Reserve and the Pascagoula River delta over two-time intervals since 1955 and focused on the forest-marsh dynamics. I found that while there were areas of forest transitioning to marsh and the rates of these transitions increased from the first-time interval to the second, gains in marsh area cannot keep up with the amount of marsh lost to forest or water. I then used a mechanistic model to predict soil porewater salinity under different SLR scenarios and found that the maximum salinity band will move up the elevation gradient as sea level increases. This supports landward migration as salinity stress will continue to move up in elevation potentially freeing spaces for marshes to migrate into. Using Bayesian multi-level models, I found that fire management likely helps facilitate landward migration of coastal marshes by increasing productivity of salt marsh and understory vegetation in ecotone and upland forests as well as decreasing tree height growth through increased salinity stress. My findings provide insights as to how marshes respond to SLR and fire management.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Masters Thesis

Year dc:date.available

2022

Author dc:creator

• Jen, Devin

Contributors dc:contributor

• Dr. Wei Wu
• Dr. Patrick Biber
• Dr. Kevin Dillon

• Landward migration
• coastal marshes
• Grand Bay National Estuarine Research Reserve
• Sea level rise
• Fire management
• Environmental Sciences

Repository record dc:identifier

https://aquila.usm.edu/masters_theses/926

OAI identifier oai:identifier

oai:aquila.usm.edu:masters_theses-1993