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Project Summary Sheet

U.S. Geological Survey, Greater Everglades Priority Ecosystems Science (GE PES) Initiative

Fiscal Year 2006 Study Summary Report

Study Title: Synthesis of South Florida Ecosystem History Research
Study Start Date: 10/1/04   Study End Date: 9/30/07
Web Sites: http://sofia.usgs.gov/flaecohist/ and http://sofia.usgs.gov/exchange/index.html and http://sofia.usgs.gov/exchange/willard/willardsflpollen.html
Location (Subregions, Counties, Park or Refuge): Everglades NP, Biscayne NP, Big Cypress Preserve, Ten Thousand Islands NWR, Loxahatchee NWR, WCA 2, 3; Broward, Collier, Dade, Monroe, Lee and West Palm Beach Counties.
Funding Source: USGS Greater Everglades Priority Ecosystems Science (PES) Initiative
Principal Investigator(s): G. Lynn Wingard and Debra A. Willard
Study Personnel: C. Bernhardt, T. Cronin, C. Holmes, W. Orem, T. Sheehan, D. Willard, L. Wingard, USGS. J. Hudley, Contractor.
Supporting Organizations: South Florida Water Management District, ACOE, NOAA, Everglades National Park, Biscayne National Park, Big Cypress Preserve, Ten Thousand Islands NWR, Loxahatchee NWR, Florida Fish & Wildlife Conservation Commission
Associated / Linked Studies: Interrelation of Everglades Hydrology and Florida Bay Dynamics (Ecology Component), Tides and Inflows in the Mangrove Ecotone (TIME), Development and Stability of Everglades Tree Islands, ridge and Slough, and Marl Prairies, Model Development, Ecosystem History of the Southwest Coast-Shark River Slough Outflow Area, Paleosalinity as a Key for Success Criteria in South Florida Restoration, Historical Changes in Salinity, Water Quality and Vegetation in Biscayne Bay

Overview & Objective(s): Everglades restoration planning requires an understanding of the impact of natural and human-induced environmental change in shaping the current ecosystem. Recent and ongoing research in the wetlands and estuaries is documenting biotic responses to specific environmental changes in specific parts of the greater Everglades ecosystem (tree islands, sawgrass ridges, sloughs, marl prairies, mangroves) and throughout Florida and Biscayne Bays. Data generated in these projects are being evaluated in the context of possible restoration strategies to improve prediction of future ecosystem response. This project is intended to synthesize all data generated to date on the history of the Greater Everglades ecosystem and the response of various components to climatic and anthropogenically derived change. This will provide land managers with a concise summary of the most current information on ecosystem history for South Florida and it will identify gaps in information needs for additional work.

Status: All ecosystem history data for Biscayne Bay and Florida Bay have been compiled, standardized, and verified to original records; database was released April 2006 (available at http://sofia.usgs.gov/exchange/flaecohist/). Age models for the Biscayne Bay and Florida Bay cores were developed and the data are currently being compiled into an open-file report. Completion of these two data standardization steps has allowed us to proceed with quantitative analyses of the estuarine core data. Summaries of a qualitative assessment of the spatial and temporal changes in the estuaries were completed and presented at the Florida Bay Science Conference, GEER, and several meetings with the land management agencies. These data are currently being used to develop target salinity values for the estuaries. We are working with a modeler through the Southern Estuaries sub-team of RECOVER to use our paleosalinity data to predict historical salinities in different parts of the ecosystem. Development of the quantitative data sets is underway, and these data are being utilized by the modelers. All published pollen and geochronologic data from Everglades marshes, tree islands, and ridge and slough sites have been archived on the USGS SOFIA site (http://sofia.usgs.gov/exchange/willard/willardsflpollen.html) and the North American Pollen Database http://www.ncdc.noaa.gov/paleo/napd.html. Synthesis of temporal and spatial patterns of vegetation change have been presented at various meetings (GEER, National Conference on Ecosystem Restoration, and stakeholders meetings) and published in peer-reviewed journals (Ecological Monographs, Monthly Weather Review, Review of Palaeobotany and Palynology). We have completed analysis on five of the nine Loxahatchee NWR tree islands sampled during FY 04-05 in collaboration with USFWS, and the remaining samples will be completed and a report generated during FY06.

Recent Products:

Cronin, T. M., Willard, D. A., Thunell, R., Dwyer, G., Swart, P., Wingard, G., and Saenger, C., 2005, Paleoclimatic Evidence for Abrupt Climate Impacts on East Coast: North American Estuaries, Estuarine Research Federation Meeting, Norfolk, Va.

Wingard, G.L., and Hudley, J.W., 2005, The Challenges of Setting Performance Measures for South Florida's Estuaries: Nearshore Transition Zones versus Middle to Outer Bay Zones: Florida Bay Science Conference, December 2005.

Murray, J.B., Wingard, G.L., Salinity and Temperature Tolerance Experiments On Selected Florida Bay Mollusks: U.S. Geological Survey, OFR 2006-1026.

Willard, D.A., and Bernhardt, C.E., 2005. Everglades Wetland Response to Climatic and Anthropogenic Hydrologic Change: Implications for Management of the Everglades Ecosystem. George Wright Society Meeting, Philadelphia, PA, 3-2005.

Willard, D.A., Bernhardt, C.E., Holmes, C.W., Landacre, B., and Marot, M., 2006 (in press). Response of Everglades tree islands to environmental change. Ecological Monographs (Nov., 2006).

Bernhardt, C.E., Willard, D.A., Holmes, C.W., and Marot, M., in review. Climate variability and anthropogenic impacts on wetland development: the sawgrass ridge and slough landscape, Everglades, Florida. Submitted to Wetlands.

Wingard, G.L., and project members, 2006, Ecosystem History Access Database, available at http://sofia.usgs.gov/exchange/flaecohist/

Wingard, G.L., Cronin, T.M., Holmes, C.W., Ishman, S.E., and Willard, D.A., 2006, Ecosystem History of South Florida's Estuaries - What do we know and what does it mean for restoration?: Greater Everglades Ecosystem Restoration Conference, June 2006.

Wingard, G.L., (with contributions by T.M. Cronin and W. Orem), in press, Ecosystem History, chapter 3 of Nuttle, W. and Hunt, J., (eds.), Synthesis Report to Florida Bay Program Management Committee, Status of Florida Bay Research, Florida Marine Research Institute Bulletin, 58 msp., 3 figs.

Wingard, G.L., 2006, Defining Natural Freshwater Flow for Critical Ecosystems: A case study from South Florida: Geological Society of America, Abstracts, Special Meeting Sept. 2006, Managing Drought and Water Scarcity in Vulnerable Environments.

Oral presentations have been given to the Southern Estuaries Sub-Team of the RECOVER Regional Evaluation Team (6-2005, 9-2006), Loxahatchee Science Workshop (5-2006), and to Fish & Wildlife, South Florida Water Management District and ACOE personnel (8-2006). In addition, a workshop was organized on Paleoecology for the Greater Everglades Ecosystem Restoration Conference.

Planned Products:

Open File Report: Age Models for Selected Cores in Biscayne Bay and Florida Bay - Authors: Holmes, Wingard, Willard, Marot and Hudley. [Status: in preparation - expected release Fall 06]

Journal Article, potentially to be submitted to Estuaries - Historical distribution of environments in Biscayne Bay and Florida Bay - Authors: Wingard and Hudley. [Status: in preparation in review by Fall 06]

Journal Article - Application of modern analog method to definition of salinity targets in south Florida - Authors: Wingard and Hudley.

Open File Report: Influence of 20th century water management on plant communities in Everglades marl prairies - Authors: Bernhardt and Willard, [Status: in preparation - expected release Fall 2006]

Journal Article - Everglades wetland response to hydrologic fluctuations: climatic vs. human impacts - Authors: Willard, Bernhardt, Holmes, and Marot [Status: in preparation - expected release Summer 07]

Specific Relevance to Information Needs Identified in DOI's Science Plan in Support of Ecosystem Restoration, Preservation, and Protection in South Florida (DOI's Everglades Science Plan) [See Plan on SOFIA's Web site: http://sofia.usgs.gov/publications/reports/doi-science-plan/]:

One of the primary activities discussed in the DOI Science Plan is to "ensure that hydrologic performance targets accurately reflect the natural predrainage hydrology and ecology" (DOI Science Plan, p. 14). The Synthesis of ecosystem history data from the wetlands and estuaries of South Florida will provide the necessary data to achieve this goal.

Task 1 of this study supports several of the projects listed in the DOI science plan, specifically: Arthur R. Marshall Loxahatchee NWR Internal Canal Structures; Water Conservation Area 3 Decompartmentalization and Sheetflow Enhancement; and Combined Structural and Operational Plan by (a) documenting the timing of changes in tree island, ridge and slough, and marl prairie communities across the region; (b) establishing temporal and spatial patterns of vegetation development and geochemical changes on tree islands; (c) developing a model of tree-island formation that may be used in restoration of degraded islands and, possibly, creation of new islands; (d) establishing the timing of ridge and slough initiation and changes in spatial extent; and (e) evaluating the longevity and stability of marl prairie communities over the past few centuries.

The study supports the Arthur R. Marshall Loxahatchee NWR Internal Canal Structures project (LNWR; p. 39) as it (1) provides data about historic hydrologic and ecological conditions on the refuge (p. 40) and (2) helps understand the ecological effects of hydrology and water quality on refuge resources (p. 40). Specifically, the study collected and analyzed pollen assemblages from three transects of cores in the northern, central, and southern Refuge. Analysis of these cores provides critical data on the timing and extent of vegetation change and the impact of 20th century hydrologic changes on Refuge communities. The study supports the Water Conservation Area 3 Decompartmentalization and Sheetflow Enhancement project (DECOMP; p. 66) as it (1) helps understand the linkages among the geologic, hydrologic, chemical, and biological processes that shaped the predrainage Everglades (p. 68); (2) helps understand the critical factors for sustaining tree islands, ridge and slough habitats, and marl prairies (p. 68); and (3) helps understand the effects of different hydrologic regimes and ecological processes on restoring and maintaining ecosystem function (p. 69). These goals are addresses through reconstruction of patterns of tree-island development in different parts of the system, evaluation of timing and extent of ridge and slough change, and documentation of pre- and post-drainage extent of marl prairie systems.

This study supports the Combined Structural and Operational Plan project (CSOP and Mod Waters; p. 70) as it (1) generates information that will improve ecological models and make them more suitable for application of the Natural Systems Model (p. 71).

Task 2 of this study directly supports the needs of the Southern Estuaries Sub-Team (SET) of the Regional Evaluation Team (RET) of RECOVER. The SET is interested in potential data generated by this project to help set performance measures (PMs) for the southern estuaries. This team includes clients from DOI-NPS, DOI-F&WS, NOAA, ACOE, and SFWMD. Recent data obtained by SET through the simulations run for the Initial CERP Update (ICU) have returned salinity values far in excess of any anticipated; they have therefore turned to our paleosalinity data as the primary tool for setting the PMs for the southern estuaries.

In addition, this study supports the Florida Bay and Florida Keys Feasibility Study Project, the Additional Water for Everglades National Park and Biscayne Bay Feasibility Study Project, the Biscayne Bay Coastal Wetlands Project, the Southern Golden Gate Estates Hydrologic Restoration, and the Southwest Feasibility Study Projects. This study supports these projects by 1) synthesizing research to understand the predrainage hydrology, including the amount, timing and seasonality of freshwater delivered to the estuaries of south Florida historically; 2) examining the historical environmental conditions, including the linkage between hydrology (water quality and quantity), ecology, and habitats; 3) providing the modelers with data on historic conditions in order to set targets and performance measures that reflect natural hydrologic patterns; 4) providing long-term historical data on trends and cycles within the biological component of the ecosystem that can be forecasted to predict the effects of implementation of hydrologic restoration on the ecology of coastal communities

This study supports the Florida Bay and Florida Keys Feasibility Study Project by addressing the questions 1) What are the links between impediment to circulation created by the causeway and the ecology of Florida Bay . . .?" (DOI Science Plan, p. 64), "What are the links between freshwater inflows to Florida Bay and the ecology of the bay?" (p. 65), and "What is the ecological response to hydrologic change?" (p. 66). This study supports the Additional Water for Everglades National Park and Biscayne Bay Feasibility Study by addressing the questions "What were the physical and ecological conditions in Shark River and Taylor Sloughs and Biscayne Bay prior to drainage and modification . . ." (DOI Plan p. 63), "What are the hydrologic targets needed to mimic historic flows . . . ? (p. 63). This study supports the Biscayne Bay Coastal Wetlands Project by addressing the questions "How much freshwater, and in what seasonal patterns, was delivered historically to Biscayne Bay?" (DOI Plan, p. 63), "What are the links between hydrology and ecology in the Biscayne Bay coastal wetlands?" (p. 64), and "What are the key indicators of natural ecological response . . ." and "what are the baseline conditions of the indicators?" (p. 66). The data generated by this project are particularly valuable because they provide 100 to 500 years worth of data on changes to the system. This study supports the Southern Golden Gate Estates Hydrologic Restoration Project by providing long-term (100-500 years) data on natural hydrologic patterns that can be used to set targets for freshwater inflows (p. 50). This study supports the Southwest Feasibility Study Project by providing predrainage hydrologic and ecologic conditions that can be used to set the hydrologic targets (p. 50).

Key Findings:

Results from the qualitative summary of the estuarine data indicate the following:

  • Changes were occurring in the estuarine system prior to 1900 - at most sites there is a gradual increase in salinity over time. These changes are consistent with sea level rise.
  • HOWEVER - the rate of estuarine change has increased in the 20th century at many sites.
  • Homogenization of the estuarine environment seems to be taking place in the later part of the 20th century. Euryhaline, lower diversity environments are found in areas that were polyhaline and more diverse around 1900.
  • Everglades plant community composition and distribution were affected by periodic, multidecadal droughts throughout the history of the ecosystem. In some instances, these droughts triggered apparently permanent shifts in community type; in others, vegetation returned to its previous state within decades.
  • Hydrologic modification of the Everglades wetland during the 20th century altered plant community composition and spatial extent in an unprecedented manner. Specific vegetation responses depend on location within the system and magnitude of hydrologic change.



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