HR: 10:55h
AN: B31G-03    [PDF]
TI: The History of Land-Use Change in the South Florida Ecosystem: Paleoecologic Data as a Guide for Restoration
AU: * Wingard, G L
EM: lwingard@usgs.gov
AF: U.S. Geological Survey, MS 926A, National Center 12201 Sunrise Valley Drive, Reston, VA 20192 United States
AU: Cronin, T M
EM: tcronin@usgs.gov
AF: U.S. Geological Survey, MS 926A, National Center 12201 Sunrise Valley Drive, Reston, VA 20192 United States
AU: Dwyer, G S
EM: gsd3@duke.edu
AF: Duke University, Division of Earth and Ocean Sciences 103 Old Chemistry Building, Durhan, NC 27708 United States
AU: Holmes, C W
EM: cholmes@usgs.gov
AF: U.S. Geological Survey, Center for Coastal Research 600 Fourth Street South, St. Petersburg, FL 33701 United States
AU: Ishman, S E
EM: sishman@geo.siu.edu
AF: Southern Illinois University, Geology Department Mail Code 4324, Carbondale, IL 62901 United States
AB: The south Florida ecosystem has undergone profound changes during the last century as a result of urbanization, agricultural development, and the construction of a massive water control system - the Central and Southern Florida (C\&SF) Project. Created in 1948, the C\&SF Project was designed for flood protection and to provide water for people and agricultural development. The extensive network of canals, levees, and water-control structures cover over 18,000 square miles and have completely altered the natural sheet flow of water across the land. Water was, and is, the principal driving force of this unique subtropical ecosystem, a significant portion of which is public land, including Everglades National Park, Biscayne National Park, Big Cypress National Preserve, the Florida Keys National Marine Sanctuary, Dry Tortugas National Park, and six National Wildlife Refuge Complexes. The Comprehensive Everglades Restoration Plan (CERP) has been designed in an effort to restore more natural water delivery to the ecosystem. This plan will cost over 8 billion dollars and take more than 30 years to complete. To successfully implement the CERP, land managers and restoration planners need answers to questions such as what are our restoration targets? What conditions are we restoring the system to? What portion of the changes seen in the 20th century can be attributed to land-use changes and what portion to natural change? What are the impacts on living resources? Paleoecologic and biochemical research is providing the answers to these questions. Analyses of cores from Florida Bay and Biscayne Bay have highlighted the following important findings. (1) Although land-use changes have played a role in determining salinity for Florida Bay as a whole, salinity is more strongly correlated to rainfall than any other single factor. (2) Anthropogenic activity influences the magnitude of salinity variations seen in recent times in Florida Bay, and they probably act on a local basis to influence salinity patterns near areas of canal outflow. (3) Declines in species diversity and increases in dominance of salinity-tolerant species have occurred since the 1980s in several benthic invertebrate groups in different regions of Florida Bay. (4) Increases in abundance and/or density of sub-aquatic vegetation appear to have occurred in the last 50 years, compared to the first half of the 20th century. 5) In central Biscayne Bay salinities have become increasingly marine and increasingly stable over the last century. (6) Southern Biscayne Bay has experienced relatively large swings in salinity over multi-decadal and centennial timescales, but marine influence at the site has increased over the last century. (7) Sub-aquatic vegetation in Biscayne Bay has undergone bay-wide patterns of change over the last 200-500 years but a decline in {\it Thalassia} appears to have occurred in central Biscayne Bay around the middle of the 20th century. These findings are providing land management agencies with the information they need to plan and prioritize restoration effectively.
UR: http://sofia.usgs.gov/flaecohist/
DE: 1803 Anthropogenic effects
DE: 3030 Micropaleontology
DE: 4235 Estuarine processes
DE: 4815 Ecosystems, structure and dynamics
DE: 4825 Geochemistry
SC: Biogeosciences [B]
MN: 2003 Fall Meeting