Ecosystem History: Terrestrial and Fresh-Water Ecosystems of southern Florida

Analysis of 209 pollen assemblages from surface samples in ten vegetation types in the Florida Everglades form the basis to identify wetland sub-environments from the pollen record. This calibration dataset makes it possible to infer past trends in hydrology and disturbance regime based on pollen assemblages preserved in sediment cores. Pollen assemblages from sediment cores collected in different vegetation types throughout the Everglades provide evidence on wetland response to natural fluctuations in climate as well as impacts of human alteration of Everglades hydrology. Sediment cores were located primarily in sawgrass marshes, cattail marshes, tree islands, sawgrass ridges, sloughs, marl prairies, and mangroves. The datasets contain raw data on pollen abundance as well as pollen concentration (pollen grains per gram dry sediment).

This project is designed to document the terrestrial ecosystem history of south Florida and is collaborating with other projects at the USGS and other agencies on Florida Bay, Biscayne Bay, and the Buttonwood Embankment. The specific goals of the project are 1) document the patterns of floral and faunal change at sites throughout southern Florida over the last 150 years; 2) determine whether changes occurred throughout the entire region or whether they were localized; 3) examine the floral and faunal history of the region over the last few millennia; 4) determine the baseline level of variability in the communities prior to significant human activity in the region; and 5) determine whether the fire frequency, extent, and influence can be quantified, and if so, document the fire history for sites in the region. Data generated from this project will be integrated with data from other projects to provide biotic reconstructions for the area at selected time slices and will be useful in testing ecological models designed to predict floral and faunal response to changes in environmental parameters.