Term of Award

Summer 2025

Degree Name

Master of Science in Biology (M.S.)

Document Type and Release Option

Thesis (open access)

Copyright Statement / License for Reuse

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Department

Department of Biology

Committee Chair

Lissa Leege

Committee Member 1

Isaac Park

Committee Member 2

Heather Joesting

Abstract

Sand dunes provide critical ecosystem services including storm protection by acting as natural barriers. However, these systems are threatened by human disturbance, particularly pedestrian traffic occurring at footpaths that damages dune vegetation. Vegetation is essential to dune growth and stability, as dune plants trap and bind sand. When trampled, dunes become more vulnerable to erosion and less effective at providing coastal protection. On Tybee Island, Georgia—a popular tourist destination—a vegetated dune was constructed in 2020 to enhance storm protection. This study assessed how footpaths impact dune resiliency and aimed to inform management strategies. I evaluated: (1) how characteristics of vegetation, soil, and sand accumulation differed between footpaths and undisturbed areas in both restored and established dunes; (2) the effects of experimental trampling on previously undisturbed areas; and (3) the potential for recovery after closing footpaths from public access. From March–October 2024, I collected monthly vegetation and soil data along the dune profile (toe, crest, heel, interdune), with follow-up measurements in spring 2025. Sand movement was monitored throughout the study. Results showed that footpath edges at the dune toe had altered plant community composition and increased vegetation cover compared to undisturbed areas. These areas were often dominated by Uniola paniculata, a disturbance-tolerant, dune-building grass, suggesting foot traffic filters out less tolerant species. Vegetation, soil, and sand accumulation patterns in the interdune were complex and affected by both dune type and foot traffic, warranting further study in the interdune and its importance in holding floodwater. In the field experiment, trampling reduced vegetation cover, increased soil compaction and moisture, and shifted community composition over time. The crest was particularly impacted by trampling, meaning trampling may hinder flood protection abilities. A greenhouse experiment showed trampling reduced aboveground biomass of U. paniculata. Footpaths that had been closed for one year showed minimal recovery in vegetation and soil characteristics, suggesting that recovery takes multiple growing seasons. These findings emphasize that footpaths create areas of disturbance prone to erosion. Management recommendations include narrowing existing paths, removing unnecessary ones, and prioritizing elevated bridge crossovers to minimize direct trampling and enhance dune resilience in high-traffic areas.

OCLC Number

1528904807

Research Data and Supplementary Material

Yes

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