Sapelo Research Application Form
Research Application ID: GCE-39-2013 (submitted: 01/16/2013, status: approved)
Provide a brief title for web display
Seawater Addition Long Term Experiment (SALTEx)
Investigator Information
On Island Sponsor: GCE SINERR UGAMI GADNR
| Principal Investigator: | Christopher B. Craft | ||
| Home Institution: | Indiana University at Bloomington | ||
| Award Information: | National Science Foundation grant numbers OCE-9982133 and OCE-0620959 Sub-award | ||
| Mailing Address: | Indiana University - School of Public and Environmental Affairs | Phone Number: | (812) 856-1837 |
| Room 408. MSB II. | E-mail Address: | ccraft@indiana.edu | |
| Bloomington, Indiana 47405 | |||
| Co-investigators: | Steven C. Pennings (University of Houston), Fan Li (University of Houston), Huy Vu (University of Houston), Elizabeth Ashby Nix (University of Georgia Marine Institute), Ellen Herbert (Ducks Unlimited), James Byers (University of Georgia), R. Daniel Harris (University of Georgia), Owen Langman (Indiana University) | ||
Briefly describe the project goals and methodology
Most experimental studies of saltwater intrusion on low-salinity tidal marshes have been conducted over small spatial and short temporal scales. SALTEX (Seawater Addition Long Term Experiment) is a long-term field experiment that we recently initiated in a Zizaniopsis marsh in the Altamaha River. Due to the unprecedented spatial and temporal scale of this experiment, we anticipate that it will generate new insights into how low-salinity tidal marshes respond to saltwater intrusion. We are increasing porewater salinity in 2.5 m x 2.5 m replicated (n=6) plots from the ambient salinity of <0.5 to a target range of 5-8 in two treatments: constant (press), with salinities elevated continuously to simulate sea level rise, and episodic (pulse), with salinities elevated temporarily to simulate drought.
The pulse treatment will be based on the frequency and duration of high salinity incursions at the SALTEX site generated using the SqueezeBox modeling application (Sheldon & Alber 2002, 2005). The salinity treatments will be paired with unmanipulated control plots and "inundation control" plots that are pressed or pulsed with equivalent amounts of freshwater. Water is delivered from a head tank connected to a surface irrigation system. Porewater salinity is measured in samples collected several times per week from wells in each plot, and treatment water is adjusted as necessary to keep salinity within the target range. Once the treatments are established, we will measure changes in porewater chemistry (Cl, SO4, H2S, DIC and DOC (monthly)), soil biogeochemistry (decomposition and sulfate reduction (quarterly)), vegetation (photosynthesis and respiration (quarterly)), above- and belowground biomass and species composition (annually), leaf N and herbivory (quarterly), fauna (insects and invertebrates (biannually)) and soil properties and processes (chromium reducible S, organic C, N, P and organic matter quality (annually), sedimentation and surface elevation/subsidence using SETs sediment elevation tables (biannually)). We plan to run this experiment throughout GCE-III and into GCE-IV.
Where will the project be located?
Champney Island, Altamaha Wildlife Management Area, McIntosh County, GA, lat 31.339306, long -81.466584
How will you provide GPS coordinates for study sites?
GPS coordinates are listed in the project location field
What are the expected start and end dates of the project?
Start Date: 01/01/2013 End Date: (ongoing)
How many people will access the site and at what frequency?
One technician daily, 10-12 people seasonally for 1 week at a time.
Keywords that describe your project
What equipment will be deployed in the field?
24 of 30 experimental plots will be delineated by inserting Polygal plastic sheeting 8 inches into the marsh, HDPE lumber and Thruflow decking boardwalks will be installed on the north and south sides of plots, with east-west connecting boardwalks (approx 1000 feet of boardwalk). Rod SET (RSET) benchmarks will be installed in 20 plots (4 of 6 replicates). Each plot will contain 4 1" PVC monitoring wells for porewater sampling (total of 120 wells). a 21" by 17" HDPE greenhouse gas sampling collar will be installed in each plot.
Will plants or animals be collected as part of this study?
Yes.
What are the likely impacts of the project on the site?
Placement of boardwalks (1000 ft), wells (120), cages, pvc stakes, RSET benchmarks (20), greenhouse gas sampling collars (30), and Polygal flashing (24 2.5x2.5 meter squares sunk 8 inches into the marsh). Five ppt saltwater will be applied by pumping water into the plots though a pvc "faucet" to 6 plots regularly and 6 plots for 4-6 weeks/year. Freshwater press/pulse will be added to 6 plots, respectively, in a simila rmanner. Soil cores, plant samples, and invertebrate samples will be made 4-6 times/year.
Will the project design include boardwalks? If not, explain why not.
Yes.
How long will impacts persist after the research is concluded?
All boardwalks and plot sides will be removed upon the completion of the study.
Research Permits:
U.S. Army Corps of Engineers: GCE-39-2013_Permit_PCN_CRAFT (08/01/2011-indefinite)
Georgia DNR Coastal Resources Division: GCE-39-2013_Permit_CRD_Craft (08/08/2011-indefinite)
Study Area Map:
Files attached to this application
GCE-39-2013_Maps_Champney_Island_SALTEx_Site.kml (KML file, 1.53 kb, submitted 01/30/2013)
