Sapelo Research Application Form
Research Application ID: GCE-139-2025 (submitted: 04/02/2025, status: approved)
Provide a brief title for web display
Variability across elevation gradients
Investigator Information
On Island Sponsor: GCE SINERR UGAMI GADNR
| Principal Investigator: | Amanda C. Spivak | ||
| Home Institution: | University of Georgia | ||
| Award Information: | GCEV – NSF | ||
| Mailing Address: | Marine Science Rm. 164 | Phone Number: | (706) 542-5709 |
| Marine Sciences | E-mail Address: | aspivak@uga.edu | |
| Athens, Georgia 30602-3636 | |||
| Co-investigators: | Alicia M. Wilson (University of South Carolina), Georgianne Moore (Georgia Southern University), Joel Kostka (Georgia Institute of Technology), Steven C. Pennings (University of Houston) | ||
Briefly describe the project goals and methodology
The overarching goal of this work is to describe how ecological properties change across abiotic gradients and whether variability increases near habitat transitions. This will be accomplished by conducting surveys of plants, invertebrates, soils, porewaters, and gasses at different distances relative two habitat transitions: mid-marsh-to-high marsh and high marsh-to-upland.
We will establish 3 survey zones on either side of each habitat transition (near, mid, far) as well as a survey zone at the transition boundary (i.e., 7 total zones / habitat transition). Each zone will be positioned parallel to the transition and include 5 plots (7 zones X 5 plots = 35 plots at each of 2 transitions for 70 total plots).
In mid-marsh and high marsh habitats we will use the following methods. Plots ( 1 x 4 m) will be delineated in June 2025 and marked with 6 PVC poles (3/4" diameter X 1-4' tall, depending on vegetation height). Each plot will be subdivided for different measurements. Marsh plants will be measured non-destructively (height, percent cover, leaf area) and a 0.5 x 0.5 m quadrat will be clipped at the soil surface to measure above-ground biomass. Soil cores (7.62cm × 30 cm) will be collected from clipped plots and used to determine belowground plant biomass, soil bulk density, and carbon and nitrogen content. Additional soils (~50 g) will be collected from the walls of the hole and used to characterize microbial communities. Invertebrates (snails, crab burrows) will be counted in the plots. Porewater samples will be collected from 15 cm depth using nondestructive samplers (e.g., pushpoints, rhizons). Plant and soil gas fluxes will be measured in 50 cm X 50 cm subplots by placing a clear, plexiglass chamber (50 cm X 50 cm X 150 cm) on top of marine-grade aluminum collars installed in the subplots. The purpose of the collars is to minimize disturbance to the soils and plants and reduce potential for sampling artifacts. The collars (50 cm X 50 cm) will be installed prior to gas flux measurements (several days-weeks) to allow for acclimations. Gas fluxes will be measured over 5 min incubations after which the chamber will be removed.
In the upland we will use the following methods. Survey zones will begin at the first live tree (determined by presence of living leaves, buds, fruits, etc.). Five 15 m radius plots will be established in each of the near, mid, and far zone. All plots will be marked with a single 4 ft PVC pole in the center, held in place with a 4 ft piece of steel #3 (3/8 in) rebar driven 3 ft into the ground. Up to 5 mature trees per plot will be chosen for collecting tree growth cores. Only canopy dominant trees with a diameter within 1 standard deviation of the mean diameter of all canopy dominant trees will be selected. Two cores will be collected from each tree. Each core is collected by drilling a hollow 0.33 in diameter hole to the center of the tree and extracting the wood core sample. Collecting tree cores has been shown to not harm the tree, however, out of an abundance of caution, holes will be painted with tree wound spray which helps seal the wound and prevent fungal and bacterial attack. Each plot will be further subdivided into sub-plots as described for mid- and high- marsh habitats and sampled as described above.
We will characterize site hydrology by installing 5 groundwater wells between the upland and mid-marsh. This will include (1) near the mid-marsh transition, (2) near the high marsh transition, (3) near the upland transition, (4) in the forest upland of the transition, and (5) in the upland plot farthest from the marsh-upland transition. Wells will be constructed of 1 1/4" PVC pipe and will extend 2' above the ground and reach 3 to 9' belowground. In each well a small depth level logger or conductivity-temperature-depth probe will be installed.
Sampling for each parameter will occur once during summer 2025, with teams of 2-8 people. Small teams (2 people) will make 2 additional trips to set up plots and to retrieve structural components. We request to leave 1 PVC pole to mark each plot as we plan to repeat sampling in summer 2030.
Where will the project be located?
in the rectangle within: 31.41385 -81.2929, 31.41373 -81.29524, 31.412544 -81.29509, 31.41260 -81.29281
How will you provide GPS coordinates for study sites?
I will provide a GIS file describing my study sites (ArcGIS shapefile, Google Earth KML/KMZ)
What are the expected start and end dates of the project?
Start Date: 04/30/2025 End Date: 08/31/2025
How many people will access the site and at what frequency?
Sampling for each parameter will occur once during summer 2025, with teams of 2-8 people. Small teams (2 people) will make 2 additional trips to set up plots and to retrieve structural components
Keywords that describe your project
What equipment will be deployed in the field?
PVC stakes, groundwater wells, gas flux collars will be installed. All live trees in each plot greater than 4 in diameter will be tagged at 4.5 ft using a 1 in circular aluminum tree tag attached with a 2.5 in stainless-steel nail. A subset of 10 trees (distributed across all plots) will also have a stainless-steel band for continuous manual measurements of diameter growth. Bands are 0.25 in wide and have a 2 inx4 in brass scale on one end, attached to the tree with two 4 in stainless steel screws.See additional information above
Will plants or animals be collected as part of this study?
Above and below ground plant biomass and tree cores will be collected. See above.
What are the likely impacts of the project on the site?
Placement of plots, PVC stakes, groundwater wells, and gas flux collars. Paths from parking area to plots. Soil cores and plant biomass will be collected as described above.
Will the project design include boardwalks? If not, explain why not.
How long will impacts persist after the research is concluded?
Impacts are likely to be short term and recovery is expected within the sampling growing season or the following growing season.
Study Area Map:
Files attached to this application
GCE-139-2025_Maps_marsh_landing_elevation_040225.kmz (Compressed KML file, 0.78 kb, submitted 04/02/2025)
GCE-139-2025_Documents_PERMIT-RLS20250019_Spivak_MarshLanding_signed.pdf (PDF file, 312.79 kb, submitted 05/23/2025)
GCE-139-2025_General_RLS20250019_Spivak_MarshLanding_signed.pdf (PDF file, 312.79 kb, submitted 02/12/2026)
