Sapelo Research Application Form
Research Application ID: GCE-137-2025 (submitted: 02/13/2025, status: approved)
Provide a brief title for web display
Precipitation manipulation in the high marsh--pilot study
Investigator Information
On Island Sponsor: GCE SINERR UGAMI GADNR
| Principal Investigator: | Steven C. Pennings | ||
| Home Institution: | University of Houston | ||
| Award Information: | GCE-LTER graduate student project | ||
| Mailing Address: | Department of Biology and Biochemistry | Phone Number: | (713) 743-2989 |
| University of Houston | E-mail Address: | scpennin@central.uh.edu | |
| Houston, Texas 77204-5513 | |||
| Co-investigators: | |||
Briefly describe the project goals and methodology
Our goal is to understand how high marsh plant communities respond to different levels of precipitation by simulating drought and abnormally wet conditions. We hypothesize that these infrequently flooded plants will respond positively to increased freshwater input due to decreased porewater salinity. Conversely, decreased rainfall will lead to negative outcomes in the plants. We will establish replicates in 8 sets of plots dominated by one or a mixture of the following plant species: short-form Spartina alterniflora, Sarcocornia spp., Salicornia biglovii, Batis maritima, Borrichia frutescens, Distichlis spicata, Limonium carolinianum. Each replicate has three plots: drought, increased precipitation, and control.
To simulate drought, we will build one rainout shelter in each plant group with transparent plastic shingles on top to exclude rain and redirect it via a gutter to the neighboring plot, which will serve as the "increased rainfall" treatment. Each rainout shelter will be made of 1.25" diameter PVC and will measure 1.5m tall, 2m wide, and 2m long. We will establish a control plot next to the two experimental plots. Both control and increased rainfall treatment plots only need four 0.75" diameter PVC poles standing 0.6m tall to mark the corners. Each group of plots has three treatments: rainout, added precipitation, and control.
This will serve as a pilot study to determine if measurable differences in biomass production can be found in high marsh plants by excluding or adding precipitation. If notable differences are found between treatments, a new application will be submitted later this year for a larger scale experiment with more replication.
Where will the project be located?
A total of 8 sets of plots will be deployed in two high marsh areas. See attached maps. Exact locations for each set of plots will be determined based on vegetation type when we deploy the plots.
How will you provide GPS coordinates for study sites?
I will provide a provisional map and arrange with my sponsor to collect and register GPS coordinates
What are the expected start and end dates of the project?
Start Date: 05/01/2025 End Date: 05/01/2026
How many people will access the site and at what frequency?
Three people will access each plot five times over the course of the year.
Keywords that describe your project
What equipment will be deployed in the field?
Each rainout shelter will be made of 13 pieces of PVC (1.25" diameter) and 16 plastic shingles. Six legs will be driven 30cm into the ground to hold structure in place. Each shelter will stand 1.5m tall and have an area of 2m x 2m. A gutter will collect rainwater from the rainout shelters and deliver it to the neighboring plot. The other two plots for each replicate (increased rainfall and control) will be marked by one PVC pole (0.75" diameter) standing 0.6m tall at each corner.
Will plants or animals be collected as part of this study?
Plant belowground and aboveground biomass. No animals will be collected. UGAMI collection permit will cover this activity.
What are the likely impacts of the project on the site?
The experimental treatments (decreased and increased rainfall) are likely to fall within the range of what these marshes have experienced and withstood in the past. In the short term, we expect biomass production to be diminished in drought conditions and increased in rain addition plots.
Will the project design include boardwalks? If not, explain why not.
How long will impacts persist after the research is concluded?
We anticipate impacts (decreased or increased biomass) will persist for less than one year after removing the shelters.
Research Permits:
Georgia DNR Coastal Resources Division: GCE-137-2025_Permit_RLS20250010_Pennings_Precipitation_signed (03/24/2025-indefinite)
Files attached to this application
GCE-137-2025_Maps_precipitation_manipulation_supplement.pdf (PDF file, 518.5 kb, submitted 02/13/2025)
