Marsh vegetation and soil survey at Marsh Landing, Sapelo Island GA from July 1999.

To document edaphic and vegetation patterns in a Georgia marsh, I sampled seven vegetation "zones" at Marsh Landing on Sapelo Island in July, 1999. Vegetation zones were delineated based on vegetation composition. I located 8 transects running from the Juncus zone in the high marsh down into the short S. alterniflora zone. The tall Spartina zone was not sampled. I sampled a single quadrat (0.25 m x 0.25 m) in each vegetation zone along each transect, for a total of 56 plots. I measured canopy height with a meter stick. I harvested aboveground biomass within each quadrat, sorted it to species, dried and weighed it. I measured soil water content gravimetrically by drying surface (4 cm deep) soil cores and expressing results as (water mass)/(mass of wet core). I determined porewater salinity by rehydrating dried soil cores with a known volume of deionized water, measuring the salinity of the supernatant after 48 h, and back-calculating to the volume of water originally present. I measured soil organic content as loss on ignition of dried soil cores at 450oC for 12 h. I measured relative elevation of each vegetation zone with a theodolite, with the elevation of the lowest zone arbitrarily set to zero. The resulting dataset describes how plant species composition, richness, height and biomass varies as a function of abiotic conditions in the upper part of a Georgia marsh.