The Relationship Between Dieback and Soil Composition in a St. Simons Island, Georgia Salt Marsh
Faculty Mentor
Dr. Christine Hladik
Location
Russell Union Ballroom
Type of Research
On-going
Session Format
Poster Presentation
College
School of Earth Environment & Sustainability
Department
Geosciences
Abstract
Salt marshes are vital ecosystems that provide over $8 trillion in economic value and serve as a blue carbon sink. Over the last century, salt marshes have been threatened by dieback. Dieback is the sudden loss of plant life, generally, Spartina alterniflora. The drivers of dieback development and recovery are varied, but are related to drought in concert with another stressor. Much of the prior research has focused on vegetation characteristics, while the role of marsh sediment properties remains understudied. This study examines how sediment composition and climate stressors affect the recovery rate of S. alterniflora salt marsh near St. Simons Island, Georgia. Sediment core samples were collected adjacent to two recovered marsh dieback areas that have been monitored since 2014. Additionally, plant characteristics (stem count, height, percent cover) were measured in 0.25 m2 plots near the core locations. Sediment cores have been analyzed for grain size, total organic carbon as well as, nitrogen, strontium, and barium. It is expected that soils with larger grain sizes that can retain more water will be the primary variable affecting recovery time. Plant and sediment core properties will be related to the climatic variables of sea level, precipitation, and drought using various statistical methods (ANOVA, regression). Deliverables will include maps of marsh stratigraphy, data on sediment and plant characteristics, a written thesis detailing research objectives, methods, and findings. Findings contribute to a better understanding of dieback drivers and the development of targeted conservation and restoration strategies in coastal wetlands facing increasing climate-related stress.
Program Description
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Start Date
4-23-2026 10:00 AM
End Date
4-23-2026 12:00 PM
Recommended Citation
Johnson, William, "The Relationship Between Dieback and Soil Composition in a St. Simons Island, Georgia Salt Marsh" (2026). GS4 Student Scholars Symposium. 39.
https://digitalcommons.georgiasouthern.edu/research_symposium/2026/2026/39
The Relationship Between Dieback and Soil Composition in a St. Simons Island, Georgia Salt Marsh
Russell Union Ballroom
Salt marshes are vital ecosystems that provide over $8 trillion in economic value and serve as a blue carbon sink. Over the last century, salt marshes have been threatened by dieback. Dieback is the sudden loss of plant life, generally, Spartina alterniflora. The drivers of dieback development and recovery are varied, but are related to drought in concert with another stressor. Much of the prior research has focused on vegetation characteristics, while the role of marsh sediment properties remains understudied. This study examines how sediment composition and climate stressors affect the recovery rate of S. alterniflora salt marsh near St. Simons Island, Georgia. Sediment core samples were collected adjacent to two recovered marsh dieback areas that have been monitored since 2014. Additionally, plant characteristics (stem count, height, percent cover) were measured in 0.25 m2 plots near the core locations. Sediment cores have been analyzed for grain size, total organic carbon as well as, nitrogen, strontium, and barium. It is expected that soils with larger grain sizes that can retain more water will be the primary variable affecting recovery time. Plant and sediment core properties will be related to the climatic variables of sea level, precipitation, and drought using various statistical methods (ANOVA, regression). Deliverables will include maps of marsh stratigraphy, data on sediment and plant characteristics, a written thesis detailing research objectives, methods, and findings. Findings contribute to a better understanding of dieback drivers and the development of targeted conservation and restoration strategies in coastal wetlands facing increasing climate-related stress.
