We examined benthic microbial communities in three contrasting subtidal salt marsh sediments over the course of a year to investigate the relationship between environmental conditions and benthic microbial community structure. Samples were collected monthly from a high energy, sandy beach, a tidal creek bed, and a Spartina alterniflora marsh border. The concentrations and biomasses of benthic microalgae (BMA), total and potentially active bacteria (measured by an enzyme-activated fluorogenic compound), heterotrophic protists, and metazoan meiofauna were measured at each location.

The Georgia Coastal Ecosystems (GCE) LTER site, located on the central Georgia coast, was established in 2000. The study domain encompasses three adjacent sounds (Altamaha, Doboy, Sapelo) and includes upland (mainland, barrier islands, marsh hammocks), intertidal (fresh, brackish and salt marsh) and submerged (river, estuary, continental shelf) habitats. Patterns and processes in this complex landscape vary spatially within and between sites, and temporally on multiple scales (tidal, diurnal, seasonal, and inter-annual).

The MIRADA project was launched in the fall of 2007 to establish a Microbial Biodiversity Survey and Inventory across all 13 of the major aquatic (marine and freshwater) Long Term Ecological Research (LTER) sites in the NSF US LTER Program. The long-term objective of our study is to document and describe baseline diversity and relative abundance data for both common and rare members of microbial communities and to relate this diversity to the underlying physical and chemical environment.

Accurate habitat mapping in salt marshes is important for both management and conservation goals, as it provides information essential for identifying sensitive areas and documenting changes over time as the result of sea level rise or human perturbations. The goal of this study is to characterize patterns of marsh plant distribution in the salt marshes surrounding back barrier islands (hammocks) within the Georgia Coastal Ecosystems LTER. In the summer of 2007 the GCE LTER surveyed over 50 hammocks of different origin and size.

Aerial, hyperspectral AISA imagery (http://calmit.unl.edu/champ/) at 1 m resolution was acquired at low tide on the morning of June 20, 2006 for the Duplin River watershed located within the Sapelo Island National Estuarine Reserve. The Duplin site is a Georgia Coastal Ecosystems focus for integrative studies. Ground truth habitat data, collected within two weeks of the imagery, included: salt marsh communities (plant species cover, canopy height, biomass, soil properties, invertebrate densities) and open water (chlorophyll a, total suspended matter, CDOM).

In Georgia coastal marshes, the annual marsh plant Suaeda linearis is usually found in association with oyster shell deposits. Dense piles of oyster shells in the marsh support low densities of dominant salt marsh plants but are the primary locations where we find S. linearis. We hypothesized that in oyster shell deposits, abiotic stresses (e.g. lower soil water content due to faster drainage) would decrease densities of marsh plants, therefore, lowering competition and enabling the relatively drought-resistant S. linearis to survive.

Ecological processes in salt marshes of the southeastern U.S. have historically been considered to be controlled largely by bottom-up forces (i.e. nutrient cycling, salinity, productivity), however, recent studies have demonstrated that top-down pressures such as herbivory and predation can be just as or more influential in the regulation of these ecological processes. Barrier islands of the southeastern U.S. support dense populations of top order consumers such as the American alligator (Alligator mississippiensis).

The groundwater-derived nutrient flux to estuaries and the coastal ocean can rival that of surface water inputs due to high groundwater nutrient concentrations. Groundwater inputs thus have an important impact on coastal water quality. Understanding patterns of variability in groundwater nutrient fluxes and the mechanisms generating this variability will help to inform coastal water resource management decisions. A suite of groundwater geochemical constituents has been monitored over the course of at least one year at two sites in coastal Georgia.

Seven years of oceanic and meteorological monitoring data have been collected in the Georgia Coastal Ecosystems LTER domain from 2002-2009 in order to understand the spatial and temporal patterns of temperature and salinity across the domain. Empirical orthogonal function analysis shows that temperature changes with time are dominated by 1 principal component (explains 93% of the variability) which is strongly correlated with atmospheric fluxes.

Studies suggest that high-latitude plants should be more palatable to herbivores than low-latitude conspecifics. Few studies, however, have examined whether this increased plant palatability indicates better plant quality for herbivores. We worked with three plant species and six associated herbivores along the U.S. Atlantic Coast to examine whether plant quality for herbivores increases with latitudes, and whether herbivores show local adaptation to plants from their own geographic regions.