Plant secondary succession following disturbance Dr. Steven C. Pennings University of Houston

Department of Biology and Biochemistry University of Houston Houston Texas 77204-5513 USA

scpennin@central.uh.edu https://uh.edu/nsm/biology-biochemistry/people/profiles/steven-pennings/ https://orcid.org/0000-0003-4757-7125 Georgia Coastal Ecosystems LTER Project

Dept. of Marine Sciences University of Georgia Athens Georgia 30602-3636 USA

gcelter@uga.edu https://gce-lter.marsci.uga.edu/ Dr. Steven C. Pennings University of Houston

Department of Biology and Biochemistry University of Houston Houston Texas 77204-5513 USA

scpennin@central.uh.edu https://uh.edu/nsm/biology-biochemistry/people/profiles/steven-pennings/ https://orcid.org/0000-0003-4757-7125 Principal investigator 2026

We are monitoring marsh plant community succession in plots at 12 sites (3 of these sites are on Sapelo Island) to study the recovery processes of marsh plant communities following disturbance. Plots were initially cleared in 2006 for studies of plant community interactions. Those studies have now ended, and we are monitoring the plots as they re-vegetate without manipulating them further.

Question 4: What are the underlying mechanisms by which proximity of marshes to upland habitat drives ecosystem change along lateral gradients in the intertidal zone? (more information)

marsh population density population diversity LTER NSF GCE Juncus plants Salicornia Spartina Zizaniopsis plant ecology Overall geographic extent of the research project -81.493498 -81.195661 31.552554 31.304191 2010-03-01 2012-11-01

Monitoring activity of GCE-LTER, overall budget $4,920,000

estuary marsh complex Eulonia - Transitional salt marsh/upland forest site at the upper reach of the Sapelo River near Eulonia, Georgia. The main marsh area is to the north of the channel where the upland is controlled by DNR. Several small creeks lie within the study area. Residential development is increasing on the upland areas south of the channel. A hydrographic sonde is deployed within this site attached to a private dock to the south of the main channel near the HW-17 bridge. The sonde is accessed from a dock on a private residence off of highway 17. As of late 2017 the property is owned by Linda Hornby. She asks that we notify her by text about an hour before arriving to service the sondes. There is no reason to go to this property other than for sonde work. -81.428481 -81.410732 31.546750 31.533963 Hunt Camp - Barrier island/marsh site on western Sapelo Island. This site is located at the upper reaches of the Duplin River, and is within the Sapelo Island National Estuarine Research Reserve. Existing well fields border small marsh area to northwest, some wells have been installed to south end of hammock where marsh is more extensive and permanent plots are located. Two existing hydrographic sondes and weather stations within this site are operated by SINERR (Hunt Camp dock) and UGAMI (flume dock). -81.295506 -81.258908 31.497026 31.462320 Four Mile Island - Low salt marsh/estuary site encompassing the southwestern end of Four Mile Island and the Sapelo River near Sapelo Sound. The large island is totally marsh, with no upland, and no development. Nearby areas, like "Sutherland Bluff", are developing with golf courses. A hydrographic sonde is deployed within this site attached to channel marker 4 (under U.S. Coast Guard permit). Salinity regime is similar to seawater. -81.318961 -81.292844 31.552554 31.533604 North Sapelo - High salinity marsh/Sapelo Sound site. Few or no small creeks, but one large creek is easily accessed. Further upstream upland drainage is affected by culvert at Reynolds' duck pond. Upland is heavily forested. Hydrographic sonde is deployed adjacent to this site attached to a channel marker (under U.S. Coast Guard permit). A huge mud flat is present at the northern tip of Sapelo Island. -81.233249 -81.195661 31.546868 31.515188 Meridian - Inland marsh and tidal creek site near Meridian, Georgia. The primary marsh site is to the south of the dock in front of the Sapelo Island Visitor Center. Some small creeks and one large creek (Hudson Creek) are present. Upland is heavily forested. Marsh to the north of the dock can be used for additional studies if larger areas are required. Upland to the North is being developed for residential use, so future access is uncertain. The USGS super station site (weather station plus multiple-sensor sonde) is deployed off the ferry dock. Salinity is similar to seawater because there is little freshwater input from the upland. -81.370752 -81.357256 31.463533 31.448419 Folly River - Salt marsh/tidal creek site at the Folly River near Doboy Sound. No upland areas present. The north side of Doboy Sound immediately opposite is similar, but creeks are not as nice. No existing markers are close enough for sonde deployment, so we will initially use the existing sonde at Marsh Landing operated by UGAMI for surrogate hydrographic data. -81.354413 -81.327201 31.442538 31.417640 Dean Creek - Doboy Sound/salt marsh site at the southern end of Sapelo Island near Dean Creek and the Sapelo lighthouse. A few small creeks are present, but a large creek (Dean Creek) is easily accessed. Upland is composed of small hammocks and some constructed causeways, with sand dune complexes east of Dean Creek and extending to the beach. Upper end of the watershed is affected by a culvert at Beach Road and heavy student use of marsh immediately adjacent to culvert. A hydrographic sonde is deployed in Doboy Sound near Commodore Island approximately 1.5km from this site. GCE6 is also the focus of Sapelo Island Microbial Observatory research on microbial diversity and genomics (http://simo.marsci.uga.edu) -81.299522 -81.264378 31.394072 31.371003 Carrs Island - Freshwater marsh site along the northern bank of Hammersmith Creek at the south end of Carrs Island. Upland area is heavily forested. Northern 3/4 of the island was diked for rice agriculture, but the southern 1/4 is undisturbed. A hydrographic sonde is deployed in the Altamaha River near Hammersmith Creek, adjacent to this site. -81.493498 -81.475900 31.348774 31.334364 Rockdedundy Island - Lower estuary tidal creek and marsh site at Rockdedundy Island west of Wolf Island. A hydrographic sonde is deployed approximately 2km from this site in the Altamaha River near Rockdedundy Island, attached to the US Coast Guard Daymarker 201 pilings. -81.346730 -81.326495 31.358142 31.339173 EPA7 - EPA7 site used by Steve Pennings for studies on plant secondary succession following disturbance -81.479561 -81.479561 31.337287 31.337287 EPA8 - EPA8 site used by Steve Pennings for studies on plant secondary succession following disturbance -81.409196 -81.409196 31.307917 31.307917 MSA - MSA site used by Steve Pennings for studies on plant secondary succession following disturbance -81.401970 -81.401970 31.304191 31.304191 Map (Google Earth KML/KMZ or map image) https://gce-lter.marsci.uga.edu/private/registration/files/maps/GCE-19-2011_Maps_Pennings_EPA_plots.kml Map (Google Earth KML/KMZ or map image) https://gce-lter.marsci.uga.edu/private/registration/files/maps/GCE-19-2011_Maps_Pennings_succession_study_2011.kml

Plots are located at the 10 GCE sites (except GCE 8), EPA 7, EPA 8, MS 8.

The overall plots are 3 x 3 m (four undisturbed and four cleared per site). Within each plot there are two monitoring plots. PVC pipes are used to mark the corners of monitoring plots, which are 1 x 1 m in size. PVC pipes are 0.5 inches in diameter and ~1m long. sixteen plots are established at each site for a total of 58 plots. PVC pipes will be removed by Guo or GCE techs when the project is ended.

Permit application or documentation https://gce-lter.marsci.uga.edu/private/registration/files/Permits/GCE-19-2011_Permits_NWP_Form_GCE_19.docx