What’s a town to dune? How Tybee Island is using native plants to stabilize sand dunes

Two women standing in front of a sign that says making the most of our coast.

Research on Tybee’s dune plant system is now underway by Georgia Southern University. You can follow this fascinating project by checking out updates on the city’s  FaceBook page every first Friday of the month. You can learn what flowers are blooming on the dunes, how the dunes are changing, and what this means for coastal resiliency on Tybee.

Link to the original recent blog post here by Shannon Matzke, the GSU student working on this research.

What’s a town to dune? How Tybee Island is using native plants to stabilize sand dunes.

February 23, 2021 – by Shannon Matzke, 2020-2021 Georgia Sea Grant Graduate Research Trainee

Halloween 2020 found me crouched in the sand dunes on Tybee Island trying to record accretion measurements while 25 mph winds howled and swirled the sand around me. As it turns out, trying to do fieldwork that day wasn’t my best idea. Since I began to conduct fieldwork back in May 2020, I’ve experienced extreme wind, rain, heat advisories, and frigid mornings, but those things never take away the feeling that I have of being incredibly lucky to call the beach my office.

I work in these conditions because I am a Georgia Sea Grant research trainee gathering data to use for my master’s thesis as a graduate student at Georgia Southern University. I am a member of Lissa Leege’s plant ecology lab where I have designed an experiment to study Tybee Island’s newly constructed sand dunes. These dunes were created to protect residential and commercial coastal developments and provide important habitats for animal species. My project monitors the plant growth and sand accumulation along these dunes and evaluates the results of experimental treatments which will shed light on which plant species and planting densities are most effective at accumulating sand and maintaining a sturdy dune system.

My study will continue through the summer of 2021, but I have already seen some exciting preliminary results. The vegetation planted on these dunes has exceeded expectations as far as survival is concerned. 95% of the plants surveyed along the new dunes survived their first growing season. I have also recorded positive increases in all of the vegetation growth measurements that I have collected. After their first season, the plants on average grew more stems, grew taller, and they increased their canopy cover when compared to their size at planting. Finally, I measured positive accretion in all of the planted sites on the new dune, and this accretion was on par with what I measured in pre-existing reference dunes south of the project area. This tells me that the new dunes are performing similarly to dunes that are successfully protecting developed areas from high tides and storms. In addition to comparing the vegetated constructed dune to pre-existing dune, I am using areas of the constructed dune that were left bare as a control to compare against the vegetated sites. Unlike the vegetated dunes, these bare sites are experiencing erosion which further relates the importance of adding native vegetation to any new dune construction.

I still have plenty of data to collect and work to do on this project, and I am excited to see what else I will learn. This study will provide the Georgia coast with innovative solutions to coastal management issues. It supports Marine Extension and Georgia Sea Grant’s goals of encouraging healthy coastal ecosystems and resilient communities and economies by providing Tybee with the information needed to sustain coastal sand dunes in order to promote economically important tourism and development. Additionally, the results of this study are far-reaching. They will not only be used by Tybee to develop management protocols for continuing their vegetation monitoring but also by the Georgia Department of Natural Resources to implement in other coastal areas considering restoration projects.

I am grateful to Sea Grant for supporting this project, as well as Georgia Southern, Georgia DNR Coastal Resources Division, Tybee Island, Dr. Leege, and Alan Robertson for mentoring me through it all. If dealing with a little bit of wind is what it takes for me to work in a beautiful location and conduct important research, then count me in!

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