history: terrestrial and fresh-water ecosystems of southern florida >
Project Proposal for 1998
Program: FRAGILE ENVIRONMENTS
Outside Partnerships - This project collaborates with SFWMD and their contractors to determine areas of particular research interest. SFWMD needs data on historic patterns of vegetational change and fire frequency to calibrate their landscape models. SFWMD has provided logistical support in the form of boats and helicopters and funded two technicians to accelerate processing and analysis of pollen and charcoal. Florida Geological Survey has provided some field support and access to cores. In addition to these groups, results will be shared with other federal through local government agencies and with private organizations with interests in ecosystem history.
Project Summary: Changes in terrestrial ecosystems of southern Florida have been attributed to environmental alteration over the last century, but cause and effect relationships between environmental and biotic changes have not been documented scientifically. This project analyzes the floral and faunal records of southern Florida 1) over the last 150 years to determine whether specific biotic changes are correlated with anthropogenic or natural environmental changes and 2) over the last few thousand years to establish the natural range of variability of the ecosystem.
Project Justification: Terrestrial ecosystems of south Florida have undergone numerous human disturbances, ranging from alteration of hydroperiod, fire history, and drainage patterns through implementation of the canal system to expansion of agricultural activity to the introduction of exotic species. Over historical time, dramatic changes in the ecosystem have been documented, and these changes have been attributed to various human activities. However, the natural variability of the ecosystem Is unknown and must be determined to assess the true impact of human activity on the modem ecosystem. This project is designed to document historical changes in the terrestrial ecosystem quantitatively, to date any changes and determine whether they resulted from documented human activities, and to establish the baseline level of variability in the south Florida ecosystem to estimate whether the observed changes are greater than would occur naturally.
Project Objectives: 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.
Overall Strategy, Study Design, and Planned Major Products:
A series of short cores are being collected throughout southern Florida to
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
of floral, faunal, and charcoal abundances; these cores will be dated using
21OPb and 14C.
Additionally, pollen, plant macrofossils, and invertebrate faunas will be
surface samples. These samples will be collected from sites throughout the
maximize representation of modem plant communities; the resulting data will
basis for comparison with down-core assemblages to determine how much
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
Preserve, and a more detailed overview of biotic and geochemical patterns
in the Taylor
Slough and Buttonwood Embankment regions.
YEAR 96 97 98 99 Coring ---------------- Sampling ---------------- Processing ----------------- Data Analysis ------------------ Write Papers ------------------ Drafts to Researchers ------------------ Final Drafts ----------------- Meet with Clients -------------------------- Director's Approval --
Planned Outreach Activities: We are working closely with personnel at the South Florida Water Management District 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 a seminar on results to date. We also interact with other collaborators and clients at a number of meetings throughout the year.
New Directions, Expansion of Continuing Project (if applicable):
In FY 98, we plan to complete final coring in the Taylor Slough region and
transect of cores across the northern part of Shark River Slough. This
suggested by scientists at the South Florida Water Management District and
focuses on an
area in which the vegetation may have changed in response to changes in
management practices to the east.
Deliverables, Products Completed:
Willard, D.A., Weimer, L.M., and Holmes, C.W., 1996. Vegetational changes over the last few millenia in south Florida: evidence from the pollen record. Abstracts with Programs, Geological Society of America Annual Meeting v. 28, p. A95.
Willard, D.A., and Holmes, C.W., in prep., Pollen census data and geochronology from southern Florida: sites along a nutrient gradient in Water Conservation Area 2A. U.S. Geological Survey Open-File Report.
Willard, D.A., Holmes, C.W., Fellman, C., Brewster-Wingard, G.L., and Ishman, S.E., in prep. The biotic and geochronologic record from South Florida: Mud Creek Site 1. U.S. Geological Survey Open-File Report.
Willard, D.A., and Weimer, L.M., in prep. Modem pollen assemblages from
Florida. U.S. Geological Survey Open-File Report.
97 98 99 Palynologist 1 1 1 Pollen prep/analysis 3 3 3 Charcoal/Peat prep 1 1 Diatom Analyst 1 1 Mollusk Analyst 1 1 Foram Analyst 1 1 Ostracode Analyst 1 1
Palynologist Debra Willard Pollen prep/analysis Lisa Weimer, Neil Waibel, Patrick Buchanan Charcoal/Peat prep James Murray Diatom Analyst Laura Pyle Mollusk Analyst Lynn Brewster-Wingard Foram Analyst Scott Ishman Ostracode Analyst Elisabeth Brouwers