2006 Philadelphia Annual Meeting (22–25 October 2006)

Paper No. 9
Presentation Time: 8:00 AM-12:00 PM

CLIMATE VARIABILITY, NATIVE AMERICAN TREE ISLAND OCCUPATION, AND WETLAND DEVELOPMENT IN THE FLORIDA EVERGLADES


BERNHARDT, Christopher, U.S. Geological Survey, University of Pennsylvania, 240 South 33rd Street, Philadelphia, PA 19104-6316, WILLARD, D., United States Geological Survey, National Center MS 926A, 12201 Sunrise Valley Drive, Reston, VA 20192, HORTON, Benjamin, Department of Earth and Environmental Science, University of Pennsylvania, 240 South 33rd Street, Philadelphia, PA 19104 and SCHWADRON, Margo, Southeast Archeological Center, National Park Service, 2035 E. Paul Dirac Drive, Johnson Building, Suite 120, Tallahassee, FL 32310, bechrist@sas.upenn.edu

Tree island sediments in the Everglades wetland ecosystem are valuable archives of climate and environmental change and also commonly contain an archeological record of Native American occupation. Previous research indicates that decadal-scale droughts have influenced tree island plant communities throughout Everglades's history, possibly affecting Native American inhabitants. We collected a series of piston cores and vibracores from tree islands and adjacent marshes in the Eastern Everglades Expansion Area to examine the long term Native American occupation history of these tree islands in the context of local and regional climate and to evaluate the impacts of Native American occupation on tree island development.

Pollen assemblages and archeological artifacts from the elevated, dry heads of tree islands are used to evaluate the history of occupation and its effects on the local vegetation. These data are compared with biostratigraphic (pollen) and chronostratigraphic (radiocarbon and 210Pb) analyses of sediments from the near tails of the tree islands to further relate wetland development and tree island occupation to local, regional, and global climate variability. In particular, we focus on the impacts of altered hydroperiod and vegetation communities known from the Mediaeval Warm Anomaly and Little Ice Age.