Sapelo Research Application Form
Research Application ID: UGAMI-2023-2 (submitted: 01/31/2023, status: approved)
Project Type: Grant-funded Academic Research
Application Title
Investigation of Ecological Drivers of Dune Stability to Inform Restoration Design and Management Guidance
Investigator Information
| Principal Investigator: | Christine Angelini | ||
| Home Institution: | University of Florida | ||
| Award Information: | US Army Corps of Engineers ($1.05M to UF, $900k to ERDC) | ||
| Mailing Address: | 300 Weil Hall 1949 Stadium Road P.O. Box 116550 | Phone Number: | 617-999-9509 |
| E-mail Address: | christine.angelini@essie.ufl.edu | ||
| Gainesville, Florida 32611 | |||
| Co-investigators: | Joe Morton (University of Florida), Hallie Fischman (University of Florida), Orlando Cordero (University of Florida) | ||
Project Abstract
Background and statement of need:
Coastal dune ecosystems are critically important for shoreline protection and significant resources have been allocated to their conservation and restoration. Dune vegetation is known to modify dune ecosystem response to wind, waves, and storms, but little focus has been given to understanding how vegetation, specifically belowground structures can enhance dune stability. Further, coastal dune communities often support diverse vegetation assemblages and may have similarly diverse restoration histories. Little is known about how different species and previous management activities alter sediment strength, stability, and overall dune morphology.
Objectives:
Our goal is to understand how prior dune restoration, upland development, and dune vegetation contribute to dune stability and resistance to storm damage. The field surveys proposed in this permit will be used to build an idealized model under which we can simulate dune response to storms under varied conditions. Specifically, we will measure soil sheer strength, dune slope, and above and belowground vegetation at 10 sites (3 in Georgia). Pending storm activity over the winter, we will revisit sites and note the position of any created scarps to better parameterize our model. Existing dune erosion models rarely include vegetation, despite the known role of plant roots in stabilizing sediments. Additionally, we aim to evaluate novel techniques for measuring vegetation (Ground Penetrating Radar, Drone surveys) that can be applied at larger scales and with less disturbance than traditional dune monitoring methods.
Methods:
In order to parameterize models, we will collect field data on belowground vegetation and dune geomorphology at 10 sites in Georgia and NE Florida, including Sapelo Island (Nanny Goat Beach), Saint Simons Island (Massengale Beach) and Cumberland Island (beach near South End Trail). These sites have been selected because they encompass a range of vegetation types, densities, and restoration histories. At each site, we will quantify above and belowground vegetation using several methods to evaluate novel, less-destructive survey techniques compared to more traditional methods.
To identify and estimate the biomass of aboveground vegetation, we will walk 3, 30-meter transects along the foredune slope, identify all species present, and estimate their cover and average height. We will photograph a 200-m stretch of beach using an Anafi AI Parrot Drone; using our ground-truthed transects we can identify species and estimate the biomass of vegetation along entire foredune.
We will quantify belowground vegetation biomass using more traditional coring methods and novel Ground Penetrating Radar (GPR). We will collect replicate cores (4-5 cores per site, 3cm diameter, up to 10 foot depth) using a vibracore soil corer. These cores will be brought back to the lab and sieved for biomass and grain size. We will additional scan a 50m transect along the foredune toe using Ground Penetrating Radar (GPR) to collect data on dune stratigraphy and root density of the dune grasses. GPR has been applied to identify roots in other systems, but has not been tested to measure roots in dunes (although team member Shawler has extensive experience using GPR in dunes to map past climatology).
Lastly, we will use a clinometer to measure the dune angle and a dynamic cone penetrometer to measure soil sheer strength at 20 locations along the foredune to better understand the geomorphic properties of the site.
Pending a storm hitting this region, sites will be revisited to better understand how belowground biomass and soil strength varies with depth. Using the newly formed dune scarp as a depth profile, we will measure exposed roots to estimate belowground biomass and measure shear strength along the scarp. Sites will also be re-droned at this time to see vegetation changes.
Surveys will be conducted along the foredune and upper beach. We are utilizing the drone in order to minimize the trampling impacts typically associated with vegetation surveying, and our ground-truthing transects will be run along the more stable dune toe. Additionally, we will minimize researcher disturbance by working on the beach whenever possible, with only necessary personnel entering the vegetated dune for each aspect of the surveys. We will not include any aboveground vegetation in our cores.
Project Location
Nanny Goat Beach, Sapelo Island (31.3936, -81.2625)
GPS Coordinates for Study Sites
GPS coordinates are listed in the project location field
Expected Start and End Dates of the Project
Start Date: 06/01/2023 End Date: 06/01/2024
Number and Frequency of People Accessing the Site
There will be 5 people on our project team and accessing sites, but drone Pilot Cordero will never enter the dunes. At times when remaining team members are not actively surveying, they will remain on the beach outside of any sensitive dunes or vegetation. We anticipate sampling will take 1-2 days. Pending storm activity this hurricane season, we plan to revisit each site once to survey the newly formed scarps. This will occur within a month of the storm and will involve a quick visit (<1 day) at each site. In the event of an extreme hurricane, we will ensure public safety is restored and the locations have re-opened to the public before attempting any research.
Keywords Describing the Project
Equipment Deployed in the Field
No equipment will be left in the field.
Plants and Animal Collecting
With the exception of plant root matter collected in belowground biomass cores during initial and post-storm surveys, no plants or animals will be collected.
Likely Impacts of the Project on the Site
We will take all efforts to minimize researcher impacts during these surveys. The team members have extensive experience working in dunes and will avoid all vegetation and unstable sediments. We will focus our efforts on the foredune and upper beach to minimize impacts, and utilize public site access walkways. We will fill with site sand the 4-5, 3" diameter holes that remain from coring to reduce the impacts of this work. Overall, we do not see any long-term impacts associated with this work.
Boardwalk Installation Plans
No boardwalks will be required. Any impacts caused by researchers accessing the site on foot are expected to be negligible.
Expected persistence of site impacts after the research is concluded?
Overall, we do not see any long-term impacts associated with this work.