ecosystem history: terrestrial and fresh-water ecosystems of southern florida >
Project Proposal for 1999
Continuing Project Workplan - FY 1999
Project Chief: Debra A. Willard
Objectives and Strategy: The project is designed to determine: 1) whether the distribution of vegetation changed over the south Florida region since 1850; 2) establish the timing of any such changes and determine whether they are correlated with onset of any human activities in the region; 3) determine whether such changes are manifested across the Everglades system (i.e., while increased abundances of cattails provide striking evidence of changes in hydroperiod and other edaphic characteristics near the Everglades Agricultural Area (EAA), did these changes have any affect on communities outside of the EAA?); 4) determine the baseline level of variability in biodiversity and vegetational distribution prior to human activity in the region (is it possible that the current state of the ecosystem represents an extreme in the naturally occurring cycles of change?); 5) determine whether fire frequency, extent, and influence prior to modem human disturbance of the ecosystem can be quantified; 6) if so, determine the historic equilibrium frequency of fire for a given region, climate, and floral community.
A series of short cores are being collected throughout southern Florida to document the floral, faunal, and fire history of the region in detail over the last 150 years and, on a broader scale, over the last few millenia; the particular focus is on the Taylor Slough and Buttonwood Embankment regions. Approximately 50 cores will be collected for analysis of floral, faunal, and charcoal abundances; these cores will be dated using 210Pb and 14C. Additionally, pollen, plant macrofossils, and invertebrate faunas will be analyzed from surface samples. These samples will be collected from sites throughout the region to maximize representation of modem plant communities; the resulting data will provide the basis for comparison with down-core assemblages to determine how much change in vegetational distribution has occurred. Analysis of these cores will result in a synthesis of vegetational changes at selected sites in the Water Conservation Areas, Big Cypress Preserve, and a more detailed overview of biotic and geochemical patterns in the Taylor Slough and Buttonwood Embankment regions.
This project is coordinated closely with personnel from the South Florida Water Management District (SFWMD) to ensure that our data complements their research needs wherever possible. SFWMD needs data on historic patterns of vegetational change and fire frequency to calibrate their landscape models, and our site selection has been designed to accommodate the areal coverage needed by their model.
This project is closely linked with Chuck Holmes' (WRD) Buttonwood Embankment project, Bill Orem's (EERST) Geochemical Processes project, Lynn Brewster-Wingard's (ERNGMT) Florida Bay Ecosystem History project, Scott Ishman's (ERNGMT) Biscayne Bay Ecosystem History project, Robert Halley's (Marine Geology Team) Sedimentation, Sea-Level Rise, and Circulation in Florida Bay project, and Thomas Smith's (BRD) Landscape Dynamics of Mangroves project. 210Pb dates will be obtained from Chuck Holmes (WRD). Cross-linkages with other USGS projects are also expected to occur. In particular, Model Review; Vegetative Resistance to Flow; and Evapotranspiration Measurements and Modeling projects in the hydrologic modeling section would greatly benefit from insights into vegetation communities and ecosystem history.
Major Tasks and Deliverables
FY 1999 Activities:
FY 1999 Deliverables/Products:
PLANNED OUTREACH ACTIVITIES:
We are working closely with personnel at the South Florida Water Management District and Florida Game and Fresh-Water Fish Commission in selecting sites for analysis to maximize the impact of this research on their needs. In addition to contact via phone and e-mail, we meet with scientists at the District when we are in the area doing field work and have presented seminars on results to date. We also interact with other collaborators and clients at a number of meetings throughout the year.
In FY 99, we will undertake field work for new tree island studies underway at both SFWMD and FGFWFC; these are new multi-year projects aimed at understanding the formation and history of tree islands and the likely impact of changing water management strategies on the tree islands.
ACCOMPLISHMENTS, OUTCOMES, PRODUCTS, OUTREACH
1998 Accomplishments and Outcomes:
1998 Deliverables, Products Completed:
Willard, Debra A., Brewster-Wingard, Lynn, Fellman, Claire, and Ishman, Scott E., 1997. Paleontological Data from Mud Creek Core 1, southern Florida. USGS Open-file Report 97-736.
Willard, Debra A., 1997. Pollen census data from southern Florida: sites along a nutrient gradient in Water Conservation Area 2A. USGS Open-file Report 97-497.
Willard, Debra A., and Weimer, Lisa M., 1997. Palynological census data from surface samples in south Florida. USGS Open-file Report 97-867.
Willard, Debra A., Holmes, Charles, W., Murray, James, M., Orem, William H., and Weimer, Lisa M., Submitted. Biotic and geochemical changes in the south Florida ecosystem over the last two millennia. Science.
Weimer, Lisa M., 1998, Taylor Slough, Dade Co., Florida: A Vegetational History. M.S. Thesis, Biology Department, George Mason University, Fairfax, VA.
Willard, Debra A., and Murray, James M. in prep. Peat petrography and charcoal content of cores from southern Florida. USGS Open-file Report.
Names of Key Project Staff:
Major Equipment/Facility Needs: None