Area 1: Drivers of Change

Description Objectives Outcomes Figures Projects Publications Data Sets Show All  

Overview

In order to understand the effects of external drivers such as climate change, sea level rise, and anthropogenic alterations of the landscape, we need to document their patterns over time and space. This is similar to Q1 from GCE-II, and much of the proposed work is a direct continuation of those efforts, but we are adding studies of land use change, shoreline modification, and Native American use of the area to enhance our understanding of the human drivers of change.

Our goals are to track long-term changes in climate (average conditions and extreme events like storms) and human actions (in the watershed and adjacent uplands), and to evaluate the effects of climate and human drivers on domain boundary conditions (riverine input, runoff and infiltration from adjacent uplands, sea surface height).

We collect long-term measurements of A) climate, water chemistry, oceanic exchange, and B) human activities on the landscape in order to document how boundary conditions that affect the domain vary over time.

Components

Area 1A: Climate and human drivers of change

In order to understand the effects of external drivers such as climate change, sea level rise, and anthro pogenic alterations of the landscape, we need to document their patterns over time and space. This is similar to Q1 from GCE-II, and much of the proposed work is a direct continuation of those efforts, but we are adding studies of land use change, shoreline modification, and Native American use of the area to enhance our understanding of the human drivers of change. Our goals are to track long-term changes in climate (average conditions and extreme events like storms) and human actions (in the wat ershed and adjacent uplands), and to evaluate the effects of climate and human drivers on domain boundary conditions (riverine input, runoff and infiltration from adjacent uplands, sea surface height).

Area 1B: Human activities on the landscape

To date, our consideration of human drivers has focused on nutrient inputs to the Altamaha watershed and land use change in the adjacent uplands (McIntosh Co.). For GCE-III, we propose to expand on these efforts by a) building on the Maps and Locals (MALS) project, b) documenting shoreline modification, and c) investig ating the effects of ancient human alterations. These studies will provide us with a deeper understanding of human drivers of change in our system

Research Objectives

  • 1A.1  Environmental Drivers - Collect ongoing information on climate and oceanographic conditions, sea level, and river discharge
  • 1A.2  Environmental Drivers - Maintain eddy covariance tower in Duplin River
  • 1A.3  Environmental Drivers - Monitor Altamaha River water entering the GCE domain
  • 1A.4  Environmental Drivers - Conduct dendrochronology analysis
  • 1A.5  Measure exchange between the Duplin River and Doboy Sound (yr 1-6)
    • Description:  We will deploy acoustic Doppler current profilers (ADCPs) with a vertical array of conductivity-temperature-depth (CTD) sensors at the mouths of the 3 Sounds and at the 10-m isobath during fall (low river discharge, downwelling favorable conditions) and spring (high river discharge, upwelling favorable conditions) to measure exchange with the coastal ocean. Cruises to deploy and retrieve these instruments (see UNOLS ship-time request) will also include synoptic sampling for nutrients and carbon constituents and measure the spatial extent of the Altamaha River plume in the coastal ocean. These focused studies will enable us to better characterize exchange between the GCE domain and the continental shelf, and will provide data needed to calibrate the hydrodynamic model (Area 2).
    • Participants:  Daniela Di Iorio
  • 1B.1  Human Drivers - Assess Native American oyster harvesting practices
  • 1B.2  Human Drivers - Evaluate how human activity relates to marsh inundation patterns
  • 1B.3  Human Drivers - Track shoreline armoring
  • 1B.4  Assess changes in Native American economic systems over time and their impact on the coastal Georgia landscape (yr 1-4)
    • Description:  Humans have been living on and physically modifying the coastal landscape for over 5,000 y. Studies conducted in GCE-II suggest that humans increased the elevation of upland areas adjacent to some marshes by over 1 m by adding shell deposits (Thompson et al. in press), and that these deposits affected the composition of high marsh vegetation (Guo & Pennings in review). In GCE-III we will conduct core transects and use a combination of optically stimulated luminescence dates, radiocarbon dates, and relative dates from buried artifacts to evaluate both the timing of human occupation and formation of new marsh habitats, both of which will be useful for hindcasting “pre-development” scenarios (Area 4). We will also conduct surveys at archaeological shell test pits and investigate correlations between shell presence (and other drivers) and current marsh vegetation patterns. We hypothesize that human activities have a) modified the marsh/upland border, affecting the susceptibility of these areas to sea level rise, and b) modified the high marsh plant community.
    • Participants:  Victor Thompson

Research Outcomes by Objective

  • 1A.1  Install and maintain an eddy covariance flux tower in the Duplin River (yr 1-6)
    • 2 report:

      Activities:  2014: An eddy covariance flux tower was installed in the Duplin River in summer 2013. It has an open path infrared gas analyzer for CO2/H2O, a sonic anemometer, sensors for air temperature, humidity, PAR, total solar and long wave radiation, soil heat flux plates and soil thermocouples, a rain gauge, and a camera for phenology studies.
      2015: GCE operates an eddy covariance tower in the Duplin River that measures CO2 and H2O fluxes along with atmospheric, soil and water properties. Since the wind patterns change seasonally, we added a 2nd LICOR unit facing the other direction. We also added a pressure transducer to measure water levels in the adjacent creek.
      2016: GCE continues to operate an eddy covariance tower in the Duplin River that measures CO2 and H2O fluxes along with atmospheric, soil and water properties. We have established a data processing routine that involves signal processing (de-spiking, planar fit, detrending) and 30-minute averaging.
      2017: GCE continues to operate an eddy covariance tower in the Duplin River that measures CO2 and H2O fluxes along with atmospheric, soil and water properties. We have established a data processing routine that involves signal processing (de¬spiking, planar fit, de¬trending) and 30¬minute averaging. The flux tower has had some major repairs and services to various sensors (LICOR, PAR, pressure transducer, Anemometer cable) and communication devices (modem replacement) during this last year.
      2018: GCE continues to operate an eddy covariance tower in the Duplin River that measures CO2 and H2O fluxes along with atmospheric, soil and water properties. The flux tower sustained damage during Hurricane Matthew (10/16) and needed repairs and services to various sensors and communication devices. This past year we added an additional downwelling PAR sensor and pressure transducer, but we are experiencing ongoing challenges maintaining the CO2 sensor and anemometer.

      Results:  2016: The footprint of the flux tower varies with time of day and season. Our analyses show that 70% of the signal is from S. alterniflora-dominated areas of the salt marsh. (Results Fig. 1)
      2018: Install and maintain an eddy covariance flux tower Nahrawi et al. (submitted) used flux tower data to evaluate how the ratio between water level and vegetation height affects atmospheric CO2 exchange, with greatest reduction during high spring tides.

      Plans:  2014: A pressure transducer to measure water levels in the creek adjacent to the flux tower will be installed by Fall 2013

    • 2013 report:

      Activities:  An eddy covariance flux tower was installed in the Duplin River in summer 2013. It has an open path infrared gas analyzer for CO2/H2O, a sonic anemometer, sensors for air temperature, humidity, PAR, total solar and long wave radiation, soil heat flux plates and soil thermocouples, a rain gauge, and a camera for phenology studies.

      Plans:  A pressure transducer to measure water levels in the creek adjacent to the flux tower will be installed by Fall 2013

    • 2014 report:

      Activities:  GCE operates an eddy covariance tower in the Duplin River that measures CO2 and H2O fluxes along with atmospheric, soil and water properties. Since the wind patterns change seasonally, we added a 2nd LICOR unit facing the other direction. We also added a pressure transducer to measure water levels in the adjacent creek.

    • 2015 report:

      Activities:  GCE continues to operate an eddy covariance tower in the Duplin River that measures CO2 and H2O fluxes along with atmospheric, soil and water properties. We have established a data processing routine that involves signal processing (de-spiking, planar fit, detrending) and 30-minute averaging.

      Results:  The footprint of the flux tower varies with time of day and season. Our analyses show that 70% of the signal is from S. alterniflora-dominated areas of the salt marsh. (Results Fig. 1)

    • 2016 report:

      Activities:  GCE continues to operate an eddy covariance tower in the Duplin River that measures CO2 and H2O fluxes along with atmospheric, soil and water properties. We have established a data processing routine that involves signal processing (de¬spiking, planar fit, de¬trending) and 30¬minute averaging. The flux tower has had some major repairs and services to various sensors (LICOR, PAR, pressure transducer, Anemometer cable) and communication devices (modem replacement) during this last year.

    • 2017 report:

      Activities:  GCE continues to operate an eddy covariance tower in the Duplin River that measures CO2 and H2O fluxes along with atmospheric, soil and water properties. The flux tower sustained damage during Hurricane Matthew (10/16) and needed repairs and services to various sensors and communication devices. This past year we added an additional downwelling PAR sensor and pressure transducer, but we are experiencing ongoing challenges maintaining the CO2 sensor and anemometer.

      Results:  Install and maintain an eddy covariance flux tower Nahrawi et al. (submitted) used flux tower data to evaluate how the ratio between water level and vegetation height affects atmospheric CO2 exchange, with greatest reduction during high spring tides.

    • 2019 report:

      Activities:  A series of meteorological stations are used to characterize the GCE domain (Fig. 1). The station at Marsh Landing serves as our primary station for ClimDB. We now also generate 15-minute summaries from our eddy covariance flux tower. Referenced sea level data, offshore wind forcing, and river discharge are also tracked.

      Results:  An analysis of sea level rise rates at NOAA buoys near GCE shows that rates were 2x higher from 1999-2019 than from 1940-1999. A manuscript with these observations is currently under review at PNAS (Crotty et al. subm.).

    • 2020 report:

      Activities:  A series of meteorological stations are used to characterize the GCE domain (Fig. 1). The station at Marsh Landing serves as our primary station for ClimDB. We now also generate 15-minute summaries from our eddy covariance flux tower. Long-term sea-level data come from the NOAA 8670870 gage at Ft. Pulaski, offshore wind forcing from the NOAA 41008 NDBC buoy at Gray’s Reef; river discharge from the USGS gage at Doctortown. The GCE also co-funds USGS station 022035975 at Meridian, but it is about to be disrupted by a dock renovation so we are testing a Campbell Water Level Sensor as a potential replacement. An analysis of sea-level rise rates at NOAA buoys near GCE shows that rates were 2x higher from 1999-2019 than from 1940-1999 (Fig. 2, Crotty et al. 2020).

    • 2021 report:

      Activities:  Several meteorological stations are used to characterize the GCE domain and we operate climate stations at Marsh Landing and the flux tower. We also track sea level, offshore wind forcing, and river discharge. We have a Campbell Water Level Sensor ready to deploy to ensure that our long-term tide gage data are not disrupted by upcoming dock renovations.

      Results:  The NOAA Fort Pulaski sea level gage shows an increase in relative sea level of 3.37 mm/yr for the period of 1936-2020, and a much greater increase of 8 mm/yr since the onset of the GCE project in 2000. The number of flooding events that exceed 1.7 m in sea level height relative to mean sea level also shows an increasing trend, with more than 30 events per year in 2015, 2016, 2019, and 2020

  • 1A.2  Collect ongoing information on climate and oceanographic conditions, sea level, and river discharge (yr 1-6)
    • 2 report:

      Activities:  2014: A series of meteorological stations are used to characterize the GCE domain (Fig. 1). The station at Marsh Landing, which is operated in collaboration with SINERR, serves as our primary LTER meteorological station for ClimDB. Referenced sea level data, offshore wind forcing, and river discharge are also tracked.
      2015: A series of meteorological stations are used to characterize the GCE domain (Fig. 1 ). The station at Marsh Landing serves as our primary station for ClimDB. This year we deployed a ceilometer (purchased with Supplemental equipment funds) and a sodar to evaluate boundary layer conditions as an aid to interpretation of flux tower data.
      2016: A series of meteorological stations are used to characterize the GCE domain (Activities Fig. 1). The station at Marsh Landing serves as our primary station for ClimDB. We continue to operate a ceilometer (purchased with Supplemental equipment funds) and a sodar to evaluate boundary layer conditions as an aid to interpretation of flux tower data.
      2017: A series of meteorological stations are used to characterize the GCE domain (Fig. 1). The station at Marsh Landing serves as our primary station for ClimDB.
      2018: A series of meteorological stations are used to characterize the GCE domain (Fig. 1). The station at Marsh Landing serves as our primary station for ClimDB. In October 2016 Hurricane Matthew passed through Georgia, causing a significant storm surge (Fig. 2).

      Results:  2014: Sheldon and Burd (2013) examined variability in freshwater delivery (precipitation and discharge) to the Altamaha River estuary in relation to indices for several climate signals and found complex, seasonally alternating patterns. Understanding how climate patterns affect precipitation and river discharge will help elucidate how the estuarine ecosystem may respond to climate changes.
      2015: Initial results from the ceilometer show complicated patterns of atmospheric mixing and how the boundary layer can be influenced by the presence of fog (Fig . 1), which may have implications for estimating surface CO2 flux.
      2016: Ceilometer and sodar data were used to characterize nocturnal low-level jets. We have found that periods with low-level jets are associated with smaller jet speed, weaker turbulence, stronger atmospheric stability, and smaller turbulent kinetic energy and fluxes. These results are being written up for publication.
      2017: We developed a Fourier spectral technique that can accommodate data gaps that result from biofouling of our instruments (Fig 1). This provides us with continuous data for use in hydrodynamic models.
      2018: Collect ongoing information on climate and oceanographic conditions Zhang et al. (submitted) conducted a spectral analysis of turbulence over the salt marsh based on meteorological data from the flux tower, an acoustic profiler and a ceilometer. They found evidence that upward shear above jet cores inhibits downward movement of larger eddies, and suggest that shearsheltering is different over water than over land.

    • 2013 report:

      Activities:  A series of meteorological stations are used to characterize the GCE domain (Fig. 1). The station at Marsh Landing, which is operated in collaboration with SINERR, serves as our primary LTER meteorological station for ClimDB. Referenced sea level data, offshore wind forcing, and river discharge are also tracked.

      Results:  Sheldon and Burd (2013) examined variability in freshwater delivery (precipitation and discharge) to the Altamaha River estuary in relation to indices for several climate signals and found complex, seasonally alternating patterns. Understanding how climate patterns affect precipitation and river discharge will help elucidate how the estuarine ecosystem may respond to climate changes.

    • 2014 report:

      Activities:  A series of meteorological stations are used to characterize the GCE domain (Fig. 1 ). The station at Marsh Landing serves as our primary station for ClimDB. This year we deployed a ceilometer (purchased with Supplemental equipment funds) and a sodar to evaluate boundary layer conditions as an aid to interpretation of flux tower data.

      Results:  Initial results from the ceilometer show complicated patterns of atmospheric mixing and how the boundary layer can be influenced by the presence of fog (Fig . 1), which may have implications for estimating surface CO2 flux.

    • 2015 report:

      Activities:  A series of meteorological stations are used to characterize the GCE domain (Activities Fig. 1). The station at Marsh Landing serves as our primary station for ClimDB. We continue to operate a ceilometer (purchased with Supplemental equipment funds) and a sodar to evaluate boundary layer conditions as an aid to interpretation of flux tower data.

      Results:  Ceilometer and sodar data were used to characterize nocturnal low-level jets. We have found that periods with low-level jets are associated with smaller jet speed, weaker turbulence, stronger atmospheric stability, and smaller turbulent kinetic energy and fluxes. These results are being written up for publication.

    • 2016 report:

      Activities:  A series of meteorological stations are used to characterize the GCE domain (Fig. 1). The station at Marsh Landing serves as our primary station for ClimDB.

      Results:  We developed a Fourier spectral technique that can accommodate data gaps that result from biofouling of our instruments (Fig 1). This provides us with continuous data for use in hydrodynamic models.

    • 2017 report:

      Activities:  A series of meteorological stations are used to characterize the GCE domain (Fig. 1). The station at Marsh Landing serves as our primary station for ClimDB. In October 2016 Hurricane Matthew passed through Georgia, causing a significant storm surge (Fig. 2).

      Results:  Collect ongoing information on climate and oceanographic conditions Zhang et al. (submitted) conducted a spectral analysis of turbulence over the salt marsh based on meteorological data from the flux tower, an acoustic profiler and a ceilometer. They found evidence that upward shear above jet cores inhibits downward movement of larger eddies, and suggest that shearsheltering is different over water than over land.

    • 2019 report:

      Activities:  The GCE eddy covariance flux tower on the Duplin River measures CO2, H2O, weather conditions, radiation, water levels, and soil temperature. This past year we registered the tower with the Ameriflux network, installed additional radiation sensors and a second soil temperature gauge, standardized the processing of raw eddy covariance fluxes, and developed methodologies for integrating fluxes and exploring uncertainty in the data.

      Results:  : Eddy covariance data collected in 2019 have been processed to the levels of 30-minute net ecosystem exchange (NEE), gap-filled, and partitioned into gross primary production and ecosystem respiration. Feagin et al. (in press) included GCE data in a larger effort that used eddy covariance data to create a MODIS-based blue carbon model to estimate GPP of tidal wetlands.

    • 2020 report:

      Activities:  The GCE eddy covariance flux tower on the Duplin River measures CO2 and H2O fluxes, weather conditions, radiation, water levels, and soil temperature. Maintenance is conducted on a regular basis including replacement of thermocouples, sensor cleaning and calibration. In 2019 we installed additional radiation sensors to improve our estimations of nighttime respiration and daytime fAPAR (fraction of absorbed PAR) for accurate GPP modeling, along with a second soil temperature and water level gauge in order to measure spatial variation in these parameters. We have implemented a data integration methodology to gap-fill and combine CO2 flux data from two different CO2 sensors and have now produced a continuous 30-min NEE dataset from 2014 to the present that provides information on marsh productivity over time. We are working to estimate respiration using a novel machine learning model so that we can partition NEE into gross primary production (GPP) and ecosystem respiration (R). As noted below in the “Cross-site” section, we plan to compare GPP annual budgets with other salt marsh flux tower sites in the east and the Gulf coast (Plum Island LTER, North Inlet, SC, and Grand Bay, MS).

    • 2021 report:

      Activities:  The GCE flux tower on the Duplin River measures CO2/H2O, weather conditions, radiation, water levels, and soil temperature. Maintenance is conducted on a regular basis including replacement of thermocouples, sensor cleaning and calibration.

      Results:  We have developed a workflow to process raw 10Hz eddy covariance data to 30-min net ecosystem exchange (NEE). Nahrawi et al. (2020) evaluated data from 2014-15 and demonstrated that NEE responds to both seasonal and tidal variation

  • 1A.3  Collect monthly samples of Altamaha River water entering the GCE domain, and analyze it for dissolved inorganic nutrients, DIC, alkalinity and pH (yr 1-6)
    • 2 report:

      Activities:  2014: We collect monthly samples of the river water entering the GCE domain via the Altamaha River for analysis of dissolved inorganic nutrients, DIC, alkalinity and pH
      2015: We collect monthly samples of the river water entering the GCE domain via the Altamaha River for analysis of dissolved inorganic nutrients, DIC, alkalinity and pH.
      2016: We collect monthly samples of the river water entering the GCE domain via the Altamaha River for analysis of dissolved inorganic nutrients, DIC, alkalinity and pH.
      2017: We collect monthly samples of the river water entering the GCE domain via the Altamaha River for analysis of dissolved inorganic nutrients, and biweekly samples of DIC, alkalinity and pH.
      2018: We collect monthly samples of the river water entering the GCE domain via the Altamaha River for analysis of dissolved inorganic nutrients, and semimonthly samples for DIC and alkalinity.

      Results:  2015: Schaefer (2014) evaluated N input and export in the 7 subwatersheds of the Altamaha River and found that cumulative upstream population density was an excellent predictor of both NO3 and total N concentrations and loads, and that there was little evidence for N processing during transit. Takagi et al. (submitted) analyzed long-term GCE observations of nutrients in the main tributaries and also found that dissolved inorganic N loads are driven by human population density. Taken together, these results suggest that N derived from human wastewater in the upper portion of the watershed is the primary contributor of in-stream N in the lower river.
      2017: DIC and TA concentrations in water entering the Altamaha River estuary are well fit by a negative power function with flow (Fig 2.) Dilution is evident at lower flows, but the more constant concentrations at higher flows suggest that additional sources become entrained from the watershed.
      2018: Collect samples of Altamaha River water entering the domain Takagi et al. (2017) conducted a longterm analysis of water quality in the tributaries of the Altamaha River (Fig. 1), exploring their relationships with discharge and anthropogenic influences.

    • 2013 report:

      Activities:  We collect monthly samples of the river water entering the GCE domain via the Altamaha River for analysis of dissolved inorganic nutrients, DIC, alkalinity and pH

    • 2014 report:

      Activities:  We collect monthly samples of the river water entering the GCE domain via the Altamaha River for analysis of dissolved inorganic nutrients, DIC, alkalinity and pH.

      Results:  Schaefer (2014) evaluated N input and export in the 7 subwatersheds of the Altamaha River and found that cumulative upstream population density was an excellent predictor of both NO3 and total N concentrations and loads, and that there was little evidence for N processing during transit. Takagi et al. (submitted) analyzed long-term GCE observations of nutrients in the main tributaries and also found that dissolved inorganic N loads are driven by human population density. Taken together, these results suggest that N derived from human wastewater in the upper portion of the watershed is the primary contributor of in-stream N in the lower river.

    • 2015 report:

      Activities:  We collect monthly samples of the river water entering the GCE domain via the Altamaha River for analysis of dissolved inorganic nutrients, DIC, alkalinity and pH.

    • 2016 report:

      Activities:  We collect monthly samples of the river water entering the GCE domain via the Altamaha River for analysis of dissolved inorganic nutrients, and biweekly samples of DIC, alkalinity and pH.

      Results:  DIC and TA concentrations in water entering the Altamaha River estuary are well fit by a negative power function with flow (Fig 2.) Dilution is evident at lower flows, but the more constant concentrations at higher flows suggest that additional sources become entrained from the watershed.

    • 2017 report:

      Activities:  We collect monthly samples of the river water entering the GCE domain via the Altamaha River for analysis of dissolved inorganic nutrients, and semimonthly samples for DIC and alkalinity.

      Results:  Collect samples of Altamaha River water entering the domain Takagi et al. (2017) conducted a longterm analysis of water quality in the tributaries of the Altamaha River (Fig. 1), exploring their relationships with discharge and anthropogenic influences.

    • 2019 report:

      Activities:  We collect monthly samples of river water entering via the Altamaha River for analysis of dissolved inorganic nutrients, DIC, alkalinity, and pH. We also completed a directed study to evaluate the DOM signatures of water entering the system.

      Results:  Letourneau and Medeiros (2019) found increased biodegradation of DOC when the discharge of the Altamaha River was high, and the DOM composition was more terrigenous in character. This paper, in JGR Biogeosciences, was featured as an EOS research spotlight.

    • 2020 report:

      Activities:  We increased our monthly sampling of Altamaha River water to weekly from Apr 2020 through Oct 2020 to capture potential changes in water quality associated with COVID19. Letourneau and Medeiros (2019) recently completed a directed study in which they evaluated the DOM signatures of water entering the system. They found increased biodegradation of DOC when the discharge of the Altamaha River was high, and the DOM composition was more terrigenous in character. This paper, in JGR Biogeosciences, was featured as an EOS research spotlight.

    • 2021 report:

      Activities:  We routinely collect monthly samples of water entering the GCE domain via the Altamaha River for analysis of nutrients, DIC, alkalinity and pH. We have experienced COVID-related delays in sample processing.

      Results:  Letourneau et al. (2021) completed an analysis of DOM composition of water entering the GCE domain (see Accomplishments). Note that the monthly median discharge of the Altamaha River exceeded 2000 m3 s-1 in 2020, which is the highest ever recorded since the start of the GCE project.

      Accomplishments:  What Drives DOM Composition in Estuaries?

  • 1A.4  Measure exchange between the estuaries and the coastal ocean (yr 2-4)
    • 2 report:

      Activities:  2014: Instruments are being prepared for deployment in year 2.5. Measure exchange between the Duplin River and Doboy Sound (yr 1-6)
      2015: We carried out 3 research cruises on the RV Savannah during which we deployed acoustic Doppler current profilers with CTD sensors. The data from these moorings will be used to help understand exchange with the coastal ocean and to inform our hydrodynamic model of the region. We also sampled nutrients and C to characterize fluxes through the system.
      2016: The GCE led 4 oceanographic cruises on the R/V Savannah in 2014, and also participated in an additional 3 cruises in the GCE domain (led by J.T. Hollibaugh for a separate NSF project). Instruments were deployed within each of the three sounds in the GCE domain and data are being used along with ship based measurements to provide information on along and cross shelf flows during each season. In addition, cruises involved measurements of inorganic C (pCO2, pH, DIC, and Total Alkalinity); organic carbon (DOC, POC, CDOM, C composition); nutrients (DIN); DNA; chlorophyll; and sediment (texture, composition). A final cruise is scheduled for 2016.
      2017: The GCE conducted an oceanographic cruise in spring 2016 (led by R. Castelao) to deploy surface drifters at the mouth of the Altamaha River during a time of peak discharge. This was the final cruise scheduled for the project.
      2018: Trajectories of surface drifters were used to provide information on nearsurface circulation over the shelf for a study of the export of terrestriallyderived material (Medeiros et al. 2017).

      Results:  2016: Cruise observations provide information on seasonal salinity variability on the shelf (Activities Fig. 2)
      2017: Observational data collected from moored ADCPs reveals net outflow to the coastal ocean (Fig 3). Comparisons are currently underway with the GCE domain model to investigate the physical forces leading to these residual flows.
      2018: Measure exchange between the mouths of the estuaries and the coastal ocean EOF analysis of cross shelf flow suggests that the primary mode of variability is related to along channel winds and Ekman dynamics, and the second mode is related to Altamaha River discharge.

      Plans:  2014: Instruments and mooring equipment is being built or acquired in order to be ready for deployment in year 2. Permits for submerged moorings are also in preparation.

    • 2013 report:

      Activities:  Instruments are being prepared for deployment in year 2.5. Measure exchange between the Duplin River and Doboy Sound (yr 1-6)

      Plans:  Instruments and mooring equipment is being built or acquired in order to be ready for deployment in year 2. Permits for submerged moorings are also in preparation.

    • 2014 report:

      Activities:  We carried out 3 research cruises on the RV Savannah during which we deployed acoustic Doppler current profilers with CTD sensors. The data from these moorings will be used to help understand exchange with the coastal ocean and to inform our hydrodynamic model of the region. We also sampled nutrients and C to characterize fluxes through the system.

    • 2015 report:

      Activities:  The GCE led 4 oceanographic cruises on the R/V Savannah in 2014, and also participated in an additional 3 cruises in the GCE domain (led by J.T. Hollibaugh for a separate NSF project). Instruments were deployed within each of the three sounds in the GCE domain and data are being used along with ship based measurements to provide information on along and cross shelf flows during each season. In addition, cruises involved measurements of inorganic C (pCO2, pH, DIC, and Total Alkalinity); organic carbon (DOC, POC, CDOM, C composition); nutrients (DIN); DNA; chlorophyll; and sediment (texture, composition). A final cruise is scheduled for 2016.

      Results:  Cruise observations provide information on seasonal salinity variability on the shelf (Activities Fig. 2)

    • 2016 report:

      Activities:  The GCE conducted an oceanographic cruise in spring 2016 (led by R. Castelao) to deploy surface drifters at the mouth of the Altamaha River during a time of peak discharge. This was the final cruise scheduled for the project.

      Results:  Observational data collected from moored ADCPs reveals net outflow to the coastal ocean (Fig 3). Comparisons are currently underway with the GCE domain model to investigate the physical forces leading to these residual flows.

    • 2017 report:

      Activities:  Trajectories of surface drifters were used to provide information on nearsurface circulation over the shelf for a study of the export of terrestriallyderived material (Medeiros et al. 2017).

      Results:  Measure exchange between the mouths of the estuaries and the coastal ocean EOF analysis of cross shelf flow suggests that the primary mode of variability is related to along channel winds and Ekman dynamics, and the second mode is related to Altamaha River discharge.

    • 2019 report:

      Activities:  We run a horizontal looking acoustic Doppler current profiler (HADCP) to measure along-channel current flow at the mouth of the Duplin River.

      Results:  Tidally averaged currents measured by the HADCP show a residual along-channel flow that is predominately outwards (Fig. 1). This may correspond to connectivity with surrounding waters of Sapelo Sound to the north and Teakettle Creek to the west during periods of high inundation (spring high tides, sea surface heights > 0).

    • 2020 report:

      Activities:  Activities and Accomplishments: Napora et al. (2019; Napora 2020) analyzed bald cypress tree ring data to document variation in tree growth from the last 5,117 years, providing insight into long-term fluctuations in climate (Fig. 3). This is now the longest dendrochronological record east of the Mississippi River.

    • 2021 report:

      Activities:  Napora (2021) completed an analysis of bald cypress tree ring data from the last 5,117 years (Fig. 4). This is now the longest dendrochronological record east of the Mississippi River.

      Results:  Variation in bald cypress tree growth shows periods of drought and provides insight into long-term fluctuations in climate (Napora et al. 2019; Napora 2021).

  • 1A.5  Measure exchange between the Duplin River and Doboy Sound (yr 1-6)
    • 2 report:

      Activities:  2014: We have acquired an H-ADCP to deploy at the mouth of the Duplin River.
      2015: We have had difficulty identifying a location for deployment of a horizontal ADCP that does not interfere with boat traffic.
      2016: We have concluded that we cannot attach a horizontal ADCP to an existing structure as originally planned and will instead need to install a piling, which requires permits from both the State DNR and the USACE. However, we have started to evaluate exchange with the FVCOM model (see Objective 2C1).
      2017: Final permits to install an H¬ADCP in the Duplin River have been obtained from GA DNR and the US ACE. Deployment is scheduled for November 2016.
      2018: The HADCP was successfully deployed in the Duplin River (Fig. 3) and has been collecting data since November 2016.

      Results:  2018: Measure exchange between the Duplin River and Doboy Sound HADCP data reveal times of significant residual outflow from the Duplin River as well as short periods of strong inflow (indicative of times of strong inundation) (Fig. 2).

      Plans:  2014: The horizontal ADCP instrument needs to be mounted on a new piling along the Duplin with cabling to shore for power and data acquisition. We are currently scouting the area to identify a location that will not interfere with boating traffic near Marsh Landing.
      2015: We will survey the channel area near Marsh Landing to find an appropriate place to drive a new piling for the ADCP, and then proceed with permitting and deployment.
      2016: We will proceed with permitting and deployment.

    • 2013 report:

      Activities:  We have acquired an H-ADCP to deploy at the mouth of the Duplin River.

      Plans:  The horizontal ADCP instrument needs to be mounted on a new piling along the Duplin with cabling to shore for power and data acquisition. We are currently scouting the area to identify a location that will not interfere with boating traffic near Marsh Landing.

    • 2014 report:

      Activities:  We have had difficulty identifying a location for deployment of a horizontal ADCP that does not interfere with boat traffic.

      Plans:  We will survey the channel area near Marsh Landing to find an appropriate place to drive a new piling for the ADCP, and then proceed with permitting and deployment.

    • 2015 report:

      Activities:  We have concluded that we cannot attach a horizontal ADCP to an existing structure as originally planned and will instead need to install a piling, which requires permits from both the State DNR and the USACE. However, we have started to evaluate exchange with the FVCOM model (see Objective 2C1).

      Plans:  We will proceed with permitting and deployment.

    • 2016 report:

      Activities:  Final permits to install an H¬ADCP in the Duplin River have been obtained from GA DNR and the US ACE. Deployment is scheduled for November 2016.

    • 2017 report:

      Activities:  The HADCP was successfully deployed in the Duplin River (Fig. 3) and has been collecting data since November 2016.

      Results:  Measure exchange between the Duplin River and Doboy Sound HADCP data reveal times of significant residual outflow from the Duplin River as well as short periods of strong inflow (indicative of times of strong inundation) (Fig. 2).

  • 1B.1  Conduct structured interviews of McIntosh County residents about environmental change (yr 1)
    • 2 report:

      Activities:  2014: We conducted in depth interviews with 20 individuals who have resided in McIntosh County for a minimum of 10 yearsas part of the cross-site “maps and locals” project, supported by Sea Grant and the National Estuarine Research Reserve.
      2015: This objective was completed in yr 1. We are collaborating with N. Heynan, who runs the CWT LTER Listening project, to use this work as the basis for a GCE Listening project.
      2016: This objective was completed in yr 1.
      2017: Completed yr 1.
      2018: Completed yr 1.

      Results:  2014: The final report from this study “Listening to and learning from local ecological knowledge: A social science pilot study in McIntosh County, GA” summarizes information about the primary environmental concerns of interviewees. These included changes in freshwater, which many attributed to ditching and draining of swamplands and linked to effects on the crab fishery.

    • 2013 report:

      Activities:  We conducted in depth interviews with 20 individuals who have resided in McIntosh County for a minimum of 10 yearsas part of the cross-site “maps and locals” project, supported by Sea Grant and the National Estuarine Research Reserve.

      Results:  The final report from this study “Listening to and learning from local ecological knowledge: A social science pilot study in McIntosh County, GA” summarizes information about the primary environmental concerns of interviewees. These included changes in freshwater, which many attributed to ditching and draining of swamplands and linked to effects on the crab fishery.

    • 2014 report:

      Activities:  This objective was completed in yr 1. We are collaborating with N. Heynan, who runs the CWT LTER Listening project, to use this work as the basis for a GCE Listening project.

    • 2015 report:

      Activities:  This objective was completed in yr 1.

    • 2016 report:

      Activities:  Completed yr 1.

    • 2017 report:

      Activities:  Completed yr 1.

    • 2019 report:

      Activities:  We are developing a detailed land use history of the Hog Hammock Community on Sapelo Island. We have also deployed data loggers in drainage ditches to evaluate salt water incursion into populated areas.

      Results:  Turck et. al. (in review) and Thompson (2019) have documented resilience and possible sustainable management practices among Native American communities.

    • 2020 report:

      Activities:  Thompson (2019) and Thompson et al. (2020) measured 37,805 oysters from Late Archaic and Mississippian archaeological sites along the coasts of GA and SC, along with radiocarbon and climate data. They demonstrated that oyster reefs were an integral part of the Native American landscape and that their sustained presence over long periods of time were likely due to the sophisticated cultural systems that governed harvesting practices. We have also mapped all oyster reefs in the GCE domain in order to connect these baseline data with paleobiological information and to assess the trajectory of modern oyster reefs.

    • 2021 report:

      Activities:  Oyster shells from three archaeological sites in the GCE domain are being processed for 18O.

      Results:  18O data indicate sea level shifts and salinity variability during periods that coincide with the abandonment of sites by Native American communities.

  • 1B.2  Evaluate market and non-market values of natural resources in McIntosh County (yr 1)
    • 2 report:

      Activities:  2014: We evaluated the potential effects of future development in McIntosh County by combining a cost of community services analysis with an ecosystem service valuation approach. Funding for this study was split with Georgia Sea Grant.
      2015: This objective was completed in yr 1 (see Schmidt et al. 2014).
      2016: This objective was completed in yr 1.
      2017: Completed yr 1.
      2018: Completed yr 1.

      Results:  2014: In a study of the value of resources in McIntosh County, Schmidt et al. (submitted) found that 1) forested wetlands generate relatively little revenue to either private landowners or in taxes to the county from extractive uses, but have very high value relative other land cover types in the provision of ecosystem services, 2) forest lands contribute much more in revenue than they receive in services, whereas residential properties cost more in services than they generate in revenue, and 3) significant gains in ecosystem service preservation, hazard reduction, and in lower costs to the county in municipal services could be achieved by restricting new development from within the 500 year floodplain.

    • 2013 report:

      Activities:  We evaluated the potential effects of future development in McIntosh County by combining a cost of community services analysis with an ecosystem service valuation approach. Funding for this study was split with Georgia Sea Grant.

      Results:  In a study of the value of resources in McIntosh County, Schmidt et al. (submitted) found that 1) forested wetlands generate relatively little revenue to either private landowners or in taxes to the county from extractive uses, but have very high value relative other land cover types in the provision of ecosystem services, 2) forest lands contribute much more in revenue than they receive in services, whereas residential properties cost more in services than they generate in revenue, and 3) significant gains in ecosystem service preservation, hazard reduction, and in lower costs to the county in municipal services could be achieved by restricting new development from within the 500 year floodplain.

    • 2014 report:

      Activities:  This objective was completed in yr 1 (see Schmidt et al. 2014).

    • 2015 report:

      Activities:  This objective was completed in yr 1.

    • 2016 report:

      Activities:  Completed yr 1.

    • 2017 report:

      Activities:  Completed yr 1.

    • 2019 report:

      Activities:  We measured 37,805 oysters from Late Archaic and Mississippian period sites and are currently compiling radiocarbon dates and climate data for these samples. We have also mapped all oyster reefs in the GCE domain.

      Results:  Thompson et al. (in review) demonstrated significant spatio-temporal variability in oyster size, with larger oysters in the lowest, and hence earliest, deposits at some sites and a non-random pattern that often clustered by island, which they ascribe to processes related to territoriality, fishing rights, and coastal environmental variability.

    • 2020 report:

      Activities:  We are developing a detailed land use history of the Hog Hammock Community on Sapelo Island to examine how property ownership and potential development interfaces with flooding patterns during extreme high tides. As part of this we have deployed data loggers in drainage ditches to evaluate salt water incursion into populated areas. A new ROA supplement will extend our ethnographic research to incorporate information on traditional ecological knowledge of coastal resources. Heynen and colleagues published both technical and popular articles on the history of land use on Sapelo Island (Heynen 2020; Bailey and Heynen 2020; Hardy and Heynen, in press).

    • 2021 report:

      Activities:  We have deployed data loggers in drainage ditches to evaluate salt water incursion into populated areas of Sapelo Island. We also continue to examine how property ownership and development interface with flooding patterns. A new ROA supplement will extend our ethnographic research to incorporate information on traditional ecological knowledge of coastal resources.

      Results:  We are examining long-term changes in land use and the combined ramifications of climate change and land loss in the Saltwater Geechee community (Hardy and Heynen 2020; Hardy et al. in press).

  • 1B.3  Incorporate information on human activities into the GCE database (yr 1-6)
    • 2 report:

      Activities:  2014: GCE took the lead on the development of a cross-site database on the extent and types of coastal armoring structures present at coastal LTER sites, which will be hosted the GCE LTER website. We also used newly-available Lidar data to develop a high-resolution hammock inventory for the state of GA.
      2015: Data from an archeological survey documenting human occupation of hammocks around Sapelo Island and a radiocarbon database for the entire Georgia coast were both uploaded to the GCE catalog.
      2016: We developed an armored shoreline GIS database based on 2013 imagery. This is being compared to a similar 2006 database to examine rates of armoring and preferential areas of armoring in the GCE domain.
      2017: We used our GIS database to assess the rate of shoreline armoring in the GCE domain between 2006 and 2013.
      2018: We are in the process of updating our GIS database to include shoreline armoring in the GCE domain based on 2017 imagery.

      Results:  2017: The number of shoreline armoring structures in McIntosh County, GA (the GCE domain) increased by 34% between 2006 and 2013, with a corresponding increase in length of 18%. Most of these were bulkheads and revetments.

    • 2013 report:

      Activities:  GCE took the lead on the development of a cross-site database on the extent and types of coastal armoring structures present at coastal LTER sites, which will be hosted the GCE LTER website. We also used newly-available Lidar data to develop a high-resolution hammock inventory for the state of GA.

    • 2014 report:

      Activities:  Data from an archeological survey documenting human occupation of hammocks around Sapelo Island and a radiocarbon database for the entire Georgia coast were both uploaded to the GCE catalog.

    • 2015 report:

      Activities:  We developed an armored shoreline GIS database based on 2013 imagery. This is being compared to a similar 2006 database to examine rates of armoring and preferential areas of armoring in the GCE domain.

    • 2016 report:

      Activities:  We used our GIS database to assess the rate of shoreline armoring in the GCE domain between 2006 and 2013.

      Results:  The number of shoreline armoring structures in McIntosh County, GA (the GCE domain) increased by 34% between 2006 and 2013, with a corresponding increase in length of 18%. Most of these were bulkheads and revetments.

    • 2017 report:

      Activities:  We are in the process of updating our GIS database to include shoreline armoring in the GCE domain based on 2017 imagery.

    • 2020 report:

      Activities:  We used aerial photography from 2018 to update our coastal armoring analysis and found a 15% increase in revetments and 23% increase in bulkheads in McIntosh County over the past 6 years (2012-2018) (see Table 1).

    • 2021 report:

      Activities:  Our last periodic assessment was completed in 2018, with the next one targeted for 2024.

      Results:  We are participating in an oyster conservation project that is evaluating the potential to use discarded shells for living shorelines and other green infrastructure on the Georgia coast.

  • 1B.4  Assess changes in Native American economic systems over time and their impact on the coastal Georgia landscape (yr 1-4)
    • 2 report:

      Activities:  2014: This past summer we investigated Kenan Field, the largest archaeological site with continuous Native American occupation on Sapelo Island (4,000 y).
      2015: We continued our investigations of human population growth in the domain (both Native Americans and historic EuroAmericans) in the context of ecological change.
      2016: We continued our investigations of human population growth in the domain (both Native Americans and historic EuroAmericans) in the context of ecological change. This past year we excavated materials from 3800 BP to provide insight into an observed large-scale decline in the radiocarbon record that occurred at that time. We are also using dendrochronology as the basis for paleoclimate reconstruction of sea level rise and drought events.
      2017: We continued our investigations of human population growth in the domain (both Native Americans and historic EuroAmericans) in the context of ecological change.
      2018: We examined shell size and morphology of eastern oysters in samples dating from the Late Archaic, Late Woodland and Late Mississippian periods to evaluate resource changes over time.

      Results:  2014: DePratter and Thompson (2013) evaluated changes in the shoreline position over the past 4000 years for the northern Georgia Coast. They documented large-scale shifts in shoreline positions that account for the timing of current landforms on the Georgia coast, and evaluated this information in the context of archaeology, ecology and geology.
      2015: We see a large-scale decline in the radiocarbon record for specific types of human settlements at around 3800 BP. We are working on a paper documenting this shift, which we believe relates to large scale environmental change.
      2017: Turck and Thompson (2016) found that human occupation of the GA coast varied in response to changes in sea level. In deltaic areas (the Altamaha River Estuary corridor) there was continuous Late Archaic occupation and intensive shellfishing as sea levels dropped, and in non-deltaic areas (most of the GCE domain) there were subsistence changes and population movement.
      2018: Assess changes in Native American economic systems over time Lulewicz et al. (2017) found that the shells of Eastern oysters decreased in size through the Late Woodland and into the Late Mississippian periods, which they suggest resulted from decreases in sea level.

    • 2013 report:

      Activities:  This past summer we investigated Kenan Field, the largest archaeological site with continuous Native American occupation on Sapelo Island (4,000 y).

      Results:  DePratter and Thompson (2013) evaluated changes in the shoreline position over the past 4000 years for the northern Georgia Coast. They documented large-scale shifts in shoreline positions that account for the timing of current landforms on the Georgia coast, and evaluated this information in the context of archaeology, ecology and geology.

    • 2014 report:

      Activities:  We continued our investigations of human population growth in the domain (both Native Americans and historic EuroAmericans) in the context of ecological change.

      Results:  We see a large-scale decline in the radiocarbon record for specific types of human settlements at around 3800 BP. We are working on a paper documenting this shift, which we believe relates to large scale environmental change.

    • 2015 report:

      Activities:  We continued our investigations of human population growth in the domain (both Native Americans and historic EuroAmericans) in the context of ecological change. This past year we excavated materials from 3800 BP to provide insight into an observed large-scale decline in the radiocarbon record that occurred at that time. We are also using dendrochronology as the basis for paleoclimate reconstruction of sea level rise and drought events.

    • 2016 report:

      Activities:  We continued our investigations of human population growth in the domain (both Native Americans and historic EuroAmericans) in the context of ecological change.

      Results:  Turck and Thompson (2016) found that human occupation of the GA coast varied in response to changes in sea level. In deltaic areas (the Altamaha River Estuary corridor) there was continuous Late Archaic occupation and intensive shellfishing as sea levels dropped, and in non-deltaic areas (most of the GCE domain) there were subsistence changes and population movement.

    • 2017 report:

      Activities:  We examined shell size and morphology of eastern oysters in samples dating from the Late Archaic, Late Woodland and Late Mississippian periods to evaluate resource changes over time.

      Results:  Assess changes in Native American economic systems over time Lulewicz et al. (2017) found that the shells of Eastern oysters decreased in size through the Late Woodland and into the Late Mississippian periods, which they suggest resulted from decreases in sea level.

Research Projects by Objective

1A. Climate, Water Chemistry and Oceanic Exchange

1. Install and maintain an eddy covariance flux tower in the Duplin River

Eddy covariance flux tower for measuring gas exchange between salt marshes and the atmosphere
description: GCE web page, plain web page
date range: ongoing (since 2012)
principal investigator(s): Daniela Di Iorio

2. Collect ongoing information on climate and oceanographic conditions, sea level, and river discharge

Altamaha River salinity modeling
description: GCE web page, plain web page
date range: ongoing (since 2000)
principal investigator(s): Merryl Alber

Georgia Coastal Ecosystems LTER Climate monitoring program
description: GCE web page, plain web page
date range: ongoing (since 2002)
principal investigator(s): Daniela Di Iorio, Dorset Hurley, Wade M. Sheldon Jr.

4. Measure exchange between the mouths of the estuary and the coastal ocean

Deployment of 7 moorings in the Georgia coastal domain
description: GCE web page, plain web page
date range: 2014 to 2015
principal investigator(s): Daniela Di Iorio

1B. Human activities on the Landscape

3. Incorporate information on human activities in the GCE database

Shoreline Survey
description: GCE web page, plain web page
date range: 2013 to 2013
principal investigator(s): Merryl Alber

Outcomes Figures and Tables

2013 Activities Figure 1

2013 Activities Figure  1

2013 Outcomes Figure 1

2013 Outcomes Figure  1

Literature Cited in Outcomes

Addes, D. 2014. Presentation: Listening to and learning from local ecological knowledge: A social science pilot study in McIntosh County, GA. Exploring the Values of the Coast. Social Coast Forum 2014, February 18-20, 2014, Charleston, South Carolina.

DePratter, C. and Thompson, V.D. 2013. Past Shorelines of the Georgia Coast. Pages 145-167 in: Life Among the Tides: Recent Archaeology on the Georgia Bight. Anthropological Papers of the American Museum of Natural History, New York.

Schaefer, S.C. 2014. Controls on nitrogen inputs, loads, and in-stream concentrations in the Altamaha River, Georgia, and beyond. Ph.D. Dissertation. University of Georgia, Athens, GA.

Schmidt, J.P., Moore, R. and Alber, M. 2014. Integrating ecosystem services and local government finances intoland use planning: A case study from coastal Georgia. Landscape and Urban Planning. 122:56 - 67. (DOI: 10.1016/j.landurbplan.2013.11.008)

Sheldon, J.E. and Burd, A.B. 2014. Alternating Effects of Climate Drivers on Altamaha River Discharge to Coastal Georgia, USA. Estuaries and Coasts. 37:772–788. (DOI: 10.1007/s12237-013-9715-z)

Takagi et al. (submitted)

All Related Publications

Journal Articles

Narron, C., O'Connell, J.L., Mishra, D., Cotten, D.L., Hawman, P. and Mao, L. 2022. Flooding in Landsat across tidal systems (FLATS): An index for intermittent tidal filtering and frequency detection in salt marsh environments. Ecological Indicators. 141:109045. (DOI: 10.1016/j.ecolind.2022.109045)

Nahrawi, H.B., Leclerc, M.Y., Pennings, S.C., Zhang, G., Singh, N. and Pahari, R. 2020. Impact of tidal inundation on the net ecosystem exchange in daytime conditions in a salt marsh. Agricultural and Forest Meteorology. 294:108133. (DOI: https://doi.org/10.1016/j.agrformet.2020.108133)

Dugan, J., Emery, K., Alber, M., Alexander, C.R. Jr., Byers, J., Gehman, A., McLenaghan, N.A. and Sojka, S. 2018. Generalizing Ecological Effects of Shoreline Armoring Across Soft Sediment Environments. Estuaries and Coasts. 41(1):180-196. (DOI: 10.1007/s12237-017-0254-x)

Gehman, A., McLenaghan, N.A., Byers, J., Alexander, C.R. Jr., Pennings, S.C. and Alber, M. 2018. Effects of small-scale armoring and residential development on the salt marsh-upland ecotone. Estuaries and Coasts. 41(1):54-67. (DOI: 10.1007/s12237-017-0300-8)

O'Connell, J. and Alber, M. 2016. A smart classifier for extracting environmental data from digital image time-series: Applications for PhenoCam data in a tidal salt marsh. Environmental Modelling & Software. 84:134-139. (DOI: 10.1016/j.envsoft.2016.06.025)

Sheldon, J.E. and Alber, M. 2006. The calculation of estuarine turnover times using freshwater fraction and tidal prism models: a critical evaluation. Estuaries and Coasts. 29(1):133-146.

Sheldon, J.E. and Alber, M. 2002. A comparison of residence time calculations using simple compartment models of the Altamaha River estuary, Georgia. Estuaries. 25(6B):1304-1317.

Conference Papers (Peer Reviewed)

Sheldon, J.E. and Alber, M. 2005. Comparing Transport Times Through Salinity Zones in the Ogeechee and Altamaha River Estuaries Using SqueezeBox. In: Hatcher, K.J. (editor). Proceedings of the 2005 Georgia Water Resources Conference. Institute of Ecology, University of Georgia, Athens, Georgia.

Sheldon, J.E. and Alber, M. 2003. Simulating material movement through the lower Altamaha River Estuary using a 1-D box model. Hatcher, K.J. (editor). Proceedings of the 2003 Georgia Water Resources Conference. Institute of Ecology, University of Georgia, Athens, Georgia.

Blanton, J.O., Alber, M. and Sheldon, J.E. 2001. Salinity response of the Satilla River Estuary to seasonal changes in freshwater discharge. Pages 619-622 in: Hatcher, K.J. (editor). Proceedings of the 2001 Georgia Water Resources Conference. Institute of Ecology, University of Georgia, Athens, Georgia.

Conference Posters and Presentations

Dugan, J., Alber, M., Alexander, C.R. Jr., Byers, J., Emery, K., Gehman, A., Lawson, S. and McLenaghan, N.A. 2015. Poster: A conceptual model for predicting the ecological effects of coastal armoring in soft-sediment environments. Coastal and Estuarine Research Federation Biennial Meeting, August 30 - September 2, 2015, Estes Park, CO.

Dugan, J., Alber, M., Alexander, C.R. Jr., Byers, J., Emery, K., Gehman, A., Lawson, S. and McLenaghan, N.A. 2015. Poster: A conceptual model for predicting the ecological effects of coastal armoring in soft-sediment environments. Coastal and Estuarine Research Federation Biennial Meeting, November 8-12, 2015, Portland, OR.

Gehman, A., McLenaghan, N.A., Byers, J., Alexander, C.R. Jr., Pennings, S.C. and Alber, M. 2015. Poster: Effects of development and shoreline armoring on the high marsh ecosystem. Benthic Society Ecology Meeting 2015, March 4-7, 2015, Quebec City, CN.

Sheldon, J.E. and Burd, A.B. 2009. Presentation: An In-depth Look at Alternating Effects of Climate Signals on Freshwater Delivery to Coastal Georgia, U.S.A. Hydrologic Prediction in Estuaries and Coastal Ecosystems. CERF 2009: Estuaries and Coasts in a Changing World, November 1-5, 2009, Portland, OR.

Sheldon, J.E. and Burd, A.B. 2007. Poster: Detecting climate signals in river discharge and precipitation data for the central Georgia coast. 2007 AERS/SEERS Meeting, March 15-17, 2007, Pine Knoll Shores, NC.

Alber, M. and Sheldon, J.E. 2006. Calculating estuary turnover times during non-steady-state conditions using freshwater fraction techniques. Southeastern Estuarine Research Society meeting, Ponte Vedra Beach, Florida.

Alber, M. and Sheldon, J.E. 2006. Presentation: Simple tools for assessing coastal systems: can we get there from here? Coastal Observing Systems Workshop, LTER All Scientists Meeting, September 20-24, 2006, Estes Park Colorado.

Sheldon, J.E. and Alber, M. 2005. Poster: New and improved: Modeling mixing time scales in the Altamaha River estuary. GCE-LTER 2005 Annual Meeting. GCE-LTER, Feb. 11-12, 2005, Athens, Georgia.

Sheldon, J.E. and Alber, M. 2005. Presentation: Beyond whole-estuary flushing times: Using transport times through salinity zones to explain chlorophyll patterns in the Altamaha River estuary (Georgia, USA). Estuarine Interactions: biological-physical feedbacks and adaptations. 2005 Estuarine Research Federation Meeting. October 16-20, 2005, Norfolk, Virginia.

Sheldon, J.E. and Alber, M. 2004. Presentation: SqueezeBox: Flow-scaled 1-D box models for estuary residence time estimates. NOS Workshop on Residence/Flushing Times in Bays and Estuaries. National Oceanic and Atmospheric Administration, June 8-9, 2004, Silver Spring, Maryland.

Sheldon, J.E. and Alber, M. 2004. Presentation: SqueezeBox: Flow-scaled 1-D box models for estuary residence time estimates. Spring 2004 meeting. Southeastern Estuarine Research Society (SEERS), October 14-16, 2004, Wilmington, North Carolina.

Sheldon, J.E. and Alber, M. 2003. Poster: Modeling mixing time scales and transport of dissolved substances in the Altamaha River estuary. 2003 LTER All Scientist's Meeting, "Embarking on a Decade of Synthesis". LTER, Sept. 18-21, 2003, Seattle, Washington.

Sheldon, J.E. and Alber, M. 2003. Presentation: The equivalence of estuarine turnover times calculated using fraction of freshwater and tidal prism models. 2003 Estuarine Research Federation meeting, Sept. 14-18, 2003, Seattle, WA.

Sheldon, J.E. and Alber, M. 2001. Poster: Any way you slice it: A comparison of residence time calculations using simple compartment models of the Altamaha River estuary. ERF 2001: An Estuarine Odyssey (16th Biennial Conference of the Estuarine Research Federation). Freshwater Inflow: Science, Policy and Management. Estuarine Research Federation, Nov. 4-8, 2001, St. Pete Beach, Florida.

Alber, M. and Sheldon, J.E. 2000. Presentation: Residence times in the Altamaha River Estuary: a progress report. Southeastern Estuarine Research Society Meeting. Southeastern Estuarine Research Society, Oct 01, 2000, Tampa, Florida.

Newsletter and Newspaper Articles

Sheldon, W.M. Jr. 2006. Mining and Integrating Data from ClimDB and USGS using the GCE Data Toolbox. In: DataBits: An electronic newsletter for Information Managers: Spring 2006. Long Term Ecological Research Network, Albuquerque, NM.

Data Sets by Research Topic

Core LTER Data Sets

Geology

Effects of Small-scale Armoring and Residential Development on the Salt Marsh/Upland Ecotone in Coastal Georgia, USA

Marsh Ecology

Eddy covariance 30-minute CO2 fluxes with accompanying biophysical variables from the GCE-LTER flux tower site from December 2018 to January 2020

Meteorology

Long-term Atmospheric, Soil and Water Sensor Data from the GCE-LTER Eddy Covariance Flux Tower on Sapelo Island, Georgia

Long-term Meteorological Data from the GCE-LTER Eddy Covariance Flux Tower on Sapelo Island, Georgia

Long-term Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 03-Jan-2003 to 31-Dec-2019

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2017 to 31-Dec-2017

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2016 to 31-Dec-2016

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2015 to 31-Dec-2015

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2014 to 31-Dec-2014

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2013 to 31-Dec-2013

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2012 to 31-Dec-2012

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2011 to 31-Dec-2011

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2010 to 31-Dec-2010

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2009 to 31-Dec-2009

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2008 to 31-Dec-2008

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2007 to 31-Dec-2007

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2006 to 31-Dec-2006

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2005 to 31-Dec-2005

Annual summaries of daily climatological observations from the National Weather Service weather station at the UGA Marine Institute on Sapelo Island, Georgia for 1958 to 2004

Annual summaries of daily climatological observations from the National Weather Service weather station at Brunswick, Georgia for 1915 to 2004

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2004 to 31-Dec-2004

Climate data from the SINERR/GCE/UGAMI weather station at Marsh Landing on Sapelo Island, Georgia, from 01-Jan-2003 to 31-Dec-2003

Daily climatological observations from Sapelo Island, Georgia, from May 1957 through July 2001

Daily climatological observations from Sapelo Island, Georgia, from June 1980 through June 2001

Plant Ecology

Leaf area index for Spartina alterniflora near the GCE-LTER Flux Tower in 2018 and 2019

Ancillary Data Sets

GCE Data Portal - NWS Brunswick climate data

GCE Data Portal - Marsh Landing data

GCE Data Portal - UGA Marine Institute climate data

GCE Data Portal - Hudson Creek/Meridian Landing data

 
LTER
NSF

This material is based upon work supported by the National Science Foundation under grants OCE-9982133, OCE-0620959, OCE-1237140 and OCE-1832178. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.