The Vascular Flora of Snake Creek Gorge in the Georgia Piedmont

Published:

March 2019

Author

Toby N. Saunders

Additional Authors

David R. Morgan

ABSTRACT Snake Creek Gorge is in the Brevard Fault Zone of the Georgia Piedmont, USA. We conducted an inventory of the vascular plants of the gorge throughout the 2016 growing season in a 20 ha study area and additionally evaluated variation in community compositions in 91 100 m2 quadrats. We measured six habitat and community characteristics in each plot: relative elevation in the gorge, slope percentage, slope aspect, canopy cover, soil pH, and basal area. Ordination analyses of the plant communities were conducted and the six plot characteristics were included to evaluate correlations between habitat and community composition. The dominant natural community was mesic forest, while other community types included dry-mesic forest, riparian zones, boggy seepage areas, and rock outcrops. We documented 436 species and subspecific taxa. In the Georgia Piedmont, 62 of the taxa are uncommon, 27 are rare—including two threatened species—and 53 are not native. Twenty of the taxa are endemic to the southeastern USA, ten are common in the Appalachians but uncommon or rare in the Georgia Piedmont, and eleven are common in the Coastal Plain but uncommon or rare in the Georgia Piedmont. Ordination showed that the characteristic most strongly correlated with community composition was relative elevation, followed by slope percentage, slope aspect, and canopy cover. Soil pH was more weakly correlated with community composition, and basal area was most weakly correlated. These findings provide baseline information that should be valuable in understanding the ecology of these unique habitats.

Keywords

Georgia flora, ordination analysis, Piedmont, plant community ecology, southeastern USA gorges