Identification_Information: Citation: Citation_Information: Originator: Debra Willard William H. Orem Publication_Date: 2006 Title: Development and Stability of Everglades Tree Islands, Ridge & Slough, & Marl Prairies Geospatial_Data_Presentation_Form: spreadsheets Online_Linkage: http://sofia.usgs.gov/projects/tree_islands/ Description: Abstract: 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). Purpose: Everglades restoration planning requires an understanding of the impact of natural and human-induced environmental change on wetland stability, and this project focuses specifically on three wetland types: tree islands, the sawgrass ridge and slough system, and marl prairies. Tree islands are considered key indicators of the health of the Everglades ecosystem because of their sensitivity to both flooding and drought conditions. Tree islands also act as a sink for nutrients in the ecosystem and may play an important role in regulating nutrient dynamics. Although management strategies to restore and even create tree islands are being formulated, the published data on their age, developmental history, geochemistry, and response to hydrologic alterations is limited. To address these issues, this project integrates floral and geochemical data with geologic and vegetational mapping activities to establish the timing of tree-island formation and impacts of both flooding and droughts on tree islands throughout the Everglades. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 1962 Ending_Date: 2007 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -81.25 East_Bounding_Coordinate: -80.2 North_Bounding_Coordinate: 27 South_Bounding_Coordinate: 25 Keywords: Theme: Theme_Keyword_Thesaurus: none Theme_Keyword: geology Theme_Keyword: tree islands Theme_Keyword: ridge and slough landscape Theme_Keyword: vegetation Theme_Keyword: pollen Theme_Keyword: marl prairies Theme_Keyword: sawgrass ridge Theme_Keyword: slough Theme_Keyword: biology Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: biota Theme_Keyword: environment Theme_Keyword: geoscientificInformation Theme_Keyword: inlandWaters Theme_Keyword: 002 Theme_Keyword: 007 Theme_Keyword: 008 Theme_Keyword: 012 Place: Place_Keyword_Thesaurus: Department of Commerce, 1995, Countries, Dependencies, Areas of Special Sovereignty, and Their Principal Administrative Divisions, Federal Information Processing Standard (FIPS) 10-4, Washington, DC, National Institute of Standards and Technology Place_Keyword: United States Place_Keyword: US Place: Place_Keyword_Thesaurus: U.S. Department of Commerce, 1987, Codes for the identification of the States, the District of Columbia and the outlying areas of the United States, and associated areas (Federal Information Processing Standard 5-2): Washington, DC, NIST Place_Keyword: Florida Place_Keyword: FL Place: Place_Keyword_Thesaurus: Department of Commerce, 1990, Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas, FIPS 6-3, Washington, DC, National Institute of Standards and Technology Place_Keyword: Broward County Place_Keyword: Collier County Place_Keyword: Miami-Dade County Place_Keyword: Monroe County Place_Keyword: Palm Beach County Place: Place_Keyword_Thesaurus: USGS Geographic Names Information System Place_Keyword: Everglades National Park Place_Keyword: Big Cypress National Preserve Place_Keyword: Loxahatchee National Wildlife Refuge Place_Keyword: Rattlesnake Ridge Place: Place_Keyword_Thesaurus: none Place_Keyword: Central Everglades Place_Keyword: SW Big Cypress Place_Keyword: Water Conservation Area 1 Place_Keyword: Water Conservation Area 2 Place_Keyword: Water Conservation Area 2A Place_Keyword: Water Conservation Area 3 Place_Keyword: Water Conservation Area 3A Place_Keyword: WCA1 Place_Keyword: WCA2 Place_Keyword: WCA3 Access_Constraints: none Use_Constraints: none Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Debra Willard Contact_Organization: U.S. Geological Survey Contact_Position: Project Chief Contact_Address: Address_Type: mailing address Address: 926A National Center City: Reston State_or_Province: VA Postal_Code: 20192 Country: USA Contact_Voice_Telephone: 703 648-5320 Contact_Facsimile_Telephone: 703 648-6953 Contact_Electronic_Mail_Address: dwillard@usgs.gov Browse_Graphic: Browse_Graphic_File_Name: http://sofia.usgs.gov/projects/tree_islands/tree_island.gif Browse_Graphic_File_Description: location of tree islands cored 1998-2000 Browse_Graphic_File_Type: GIF Browse_Graphic: Browse_Graphic_File_Name: http://sofia.usgs.gov/projects/tree_islands/images/devnstability03fig1x.gif Browse_Graphic_File_Description: Location of transects across ridges and sloughs, Water Conservation Area 3A, Everglades, Florida. Browse_Graphic_File_Type: GIF Browse_Graphic: Browse_Graphic_File_Name: http://sofia.usgs.gov/publications/ofr/03-26/figure2map.gif Browse_Graphic_File_Description: Locality of tree islands sampled in Everglades between 1998-2002 Browse_Graphic_File_Type: GIF Browse_Graphic: Browse_Graphic_File_Name: http://sofia.usgs.gov/exchange/willard/pollendata-map.gif Browse_Graphic_File_Description: Surface samples collected for pollen analysis in southern Florida Browse_Graphic_File_Type: GIF Browse_Graphic: Browse_Graphic_File_Name: http://sofia.usgs.gov//EvergladesCoreMap5-07.jpg Browse_Graphic_File_Description: Map showing core sites through 2007 Browse_Graphic_File_Type: JPEG Data_Set_Credit: Project personnel included Anne Bates, Christopher Bernhardt, Patrick Buchanan, Margo Corum, Julie Damon, Charles Holmes, David Korejwo, Bryan Landacre, Harry Lerch, Marci Marot, James Murray, William Orem, Tom Sheehan, Neil Waibel, Lisa Weimer (deceased), and Debra Willard. Assistance with the previous phase of the project was provided by: Lorraine Heisler, Tim Towles: Florida Game and Fresh-Water Fish Commission. Scientific collaboration and logistic support and elevation and vegetation data from tree islands and guidance in tree-island selection. Fred Sklar, Susan Newman, Tom Fontaine, Ken Rutchey, Yegang Wu, Steve Krupa, Cindy Bevier, Jeff Giddings: South Florida Water Management District. Scientific collaboration and logistic support, elevation and vegetation data from tree islands and guidance in tree-island selection, and data on ground-water/surface water interactions and cores with lithologic description of underlying bedrock Laura Brandt: Loxahatchee National Wildlife Refuge. Scientific collaboration and guidance on tree-island selection, vegetation data. Tom Armentano, David Jones: Everglades National Park. Scientific collaboration on tropical hammocks in Everglades National Park. David L. Dilcher: Florida Museum of Natural History. Scientific collaboration and vegetational reconstruction and evaluation of Late Holocene CO2 concentrations. Native_Data_Set_Environment: MS Excel spreadsheets Cross_Reference: Citation_Information: Originator: Willard, Debra A. Weimer, Lisa M. Publication_Date: 1997 Title: Palynological Census Data from Surface Samples in South Florida Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: USGS Open-File Report Issue_Identification: 97-0867 Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/pdf/of/ofr97867.html Cross_Reference: Citation_Information: Originator: Willard, Debra A. Publication_Date: 1997 Title: Pollen Census Data from Southern Florida: Sites Along an Nutrient Gradient in Water Conservation Area 2A Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: USGS Open-File Report Issue_Identification: 97-0497 Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/pdf/of/ofr97497.html Cross_Reference: Citation_Information: Originator: Willard, Debra A. Bernhardt, Christopher E.; Weimer, Lisa (deceased); Gamez, Desire; Cooper, Sherri R.; Jensen, Jennifer Publication_Date: 2004 Title: Atlas of Pollen and Spores of the Florida Everglades Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Palynology Issue_Identification: 28 Publication_Information: Publication_Place: Arlington, TX Publisher: American Association of Stratigraphic Palynologists Other_Citation_Details: Posted with permission from Palynology and the American Association of Stratigraphic Palynologists Online_Linkage: http://sofia.usgs.gov/publications/papers/pollen_atlas/ Cross_Reference: Citation_Information: Originator: Marshall, Curtis H. Pielke, Roger A., Sr.; Steyaert, Louis T.; Willard, Debra A. Publication_Date: 200401 Title: The Impact of Anthropogenic Land-Cover Change on the Florida Peninsula Sea Breezes and Warm Season Sensible Weather Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Monthly Weather Review Issue_Identification: v. 132, n. 1 Publication_Information: Publication_Place: Boston, MA Publisher: American Meterological Society Other_Citation_Details: Permission to post a copy of this work on the SOFIA server has been provided by the American Meterological Society Online_Linkage: http://sofia.usgs.gov/publications/papers/cover_weather/ Cross_Reference: Citation_Information: Originator: Orem, W. H. Willard, D. A.; Lerch, H. E.; Bates, A. L.; Boylan, A.; Corum, M. Publication_Date: 200302 Title: Nutrient geochemistry of sediments from two tree islands in Water Conservation Area 3B, The Everglades, Florida Geospatial_Data_Presentation_Form: book chapter Publication_Information: Publication_Place: Dordrecht, Netherlands Publisher: Kluwer Academic Publishers Other_Citation_Details: in Tree Islands of the Everglades Sklar, Fred H. and van der Valk, A. (editors) Online_Linkage: http://sofia.usgs.gov/sfrsf/rooms/wild_wet_eco/tree_islands/ch5.html Cross_Reference: Citation_Information: Originator: Kloor, Keith Publication_Date: 2001 Title: Forgotten Islands Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Audubon magazine Issue_Identification: unknown Publication_Information: Publication_Place: New York, NY Publisher: National Audobon Society Other_Citation_Details: The article is available online from Audubon Magazine. Online_Linkage: http://magazine.audubon.org/truenature/truenature0107.html Cross_Reference: Citation_Information: Originator: Willard, Debra A. Holmes, Charles W. Publication_Date: 1997 Title: Pollen and geochronological data from South Florida Taylor Creek Site 2 Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: USGS Open-File Report Issue_Identification: 97-035 Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: http://sofia.usgs.gov/flaecohist/publications/OFR97-35.pdf Cross_Reference: Citation_Information: Originator: Willard, Debra A. Weimer, Lisa M.; Riegel, W. L. Publication_Date: 2001 Title: Pollen assemblages as paleoenvironmental proxies in the Florida Everglades Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Review of Palaeobotany and Palynology Issue_Identification: v. 113, n. 4 Publication_Information: Publication_Place: Amsterdam, The Netherlands Publisher: Elsevier Science B.V. Other_Citation_Details: The full article is available via journal subscription or single article purchase. The abstract may be viewed on the Science Direct website by selecting the volume and issue number. Online_Linkage: http://www.sciencedirect.com/science/journal/00346667 Cross_Reference: Citation_Information: Originator: Willard, D. A. Holmes, C. W.; Korvela, M. S.; Mason, D.; Murray, J. B.; Orem, W. H.; Towles, T. Publication_Date: 200302 Title: Paleoecological Insights on Fixed Tree Island Development in the Florida Everglades: I. Environmental Controls Geospatial_Data_Presentation_Form: book chapter Publication_Information: Publication_Place: Dordrecht, Netherlands Publisher: Kluwer Academic Publishers Other_Citation_Details: in Tree Islands of the Everglades Sklar, F. H. and van der Valk A. (editors) Online_Linkage: http://sofia.usgs.gov/sfrsf/rooms/wild_wet_eco/tree_islands/index.html Cross_Reference: Citation_Information: Originator: Willard, D. A. Orem, W. H. Publication_Date: 2003 Title: Tree Islands of the Florida Everglades - A Disappearing Resource Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: U.SGS Open-File Report Issue_Identification: 03-26 Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: http://sofia.usgs.gov/publications/ofr/03-26/ Cross_Reference: Citation_Information: Originator: Bernhardt, C. E. Willard, D. A.; Marot, M.; Holmes, C. W. Publication_Date: 2004 Title: Anthropogenic and natural variation in Ridge and Slough pollen assemblages Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: USGS Open-File Report Issue_Identification: 2004-1448 Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: http://sofia.usgs.gov/publications/ofr/2004-1448/ Cross_Reference: Citation_Information: Originator: Willard, D. A. Holmes, C. W.; Weimer, L. M. Publication_Date: 2001 Title: The Florida Everglades Ecosystem: Climatic and Anthropogenic Impacts over the Last Two Millenia Geospatial_Data_Presentation_Form: paper Series_Information: Series_Name: Bulletins of American Paleontology Issue_Identification: v. 361 Publication_Information: Publication_Place: Ithica, NY Publisher: Paleontological Research Institute Other_Citation_Details: in Paleoecology of South Florida, B. R. Wardlaw, ed. Cross_Reference: Citation_Information: Originator: Grimm, E. C. Publication_Date: 1992 Title: CONISS: a Fortran 77 program for stratigraphically constrained cluster analysis by the mothod of incremental sum of squares Geospatial_Data_Presentation_Form: paper Series_Information: Series_Name: Computers & Geosciences Issue_Identification: v. 13, issue 1 Publication_Information: Publication_Place: Amsterdam, The Netherlands Publisher: Elsevier Science, Ltd. Other_Citation_Details: The abstract may be viewed online at the Science Direct website. The full article is available for purchase from the Science Direct website. Online_Linkage: http://www.sciencedirect.com/science/journal/00983004 Cross_Reference: Citation_Information: Originator: Traverse, A. Publication_Date: 1988 Title: Paleopalynology Geospatial_Data_Presentation_Form: book Publication_Information: Publication_Place: Boston, MA Publisher: Unwin Hyman Cross_Reference: Citation_Information: Originator: Stockmarr, J. Publication_Date: 1971 Title: Tablets with spores used in absolute pollen analysis Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Pollen et Spores Issue_Identification: v. 13 Publication_Information: Publication_Place: Paris, France Publisher: Museum national d'histoire naturelle Cross_Reference: Citation_Information: Originator: Overpeck, J. T. Webb, III, T.; Prentice, I. C. Publication_Date: 1985 Title: Quantitative interpretation of fossil pollen spectra: Dissimilarity coefficients and the method of modern analogs Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Quaternary Research Issue_Identification: v 23, issue 1 Publication_Information: Publication_Place: Amsterdam, Netherlands Publisher: Elsevier Science, Ltd. Other_Citation_Details: The abstract may be viewed online at the Science Direct website. The full article is available for purchase from the Science Direct website. Online_Linkage: http://www.sciencedirect.com/science/journal/00335894 Cross_Reference: Citation_Information: Originator: Willard, D. A. Publication_Date: 2004 Title: Tree Islands of the Florida Everglades - Long-term stability and response to hydrologic change Geospatial_Data_Presentation_Form: factsheet Series_Information: Series_Name: USGS Fact Sheet Issue_Identification: 2004-3095 Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/fs/2004/3095 Cross_Reference: Citation_Information: Originator: Bernhardt, C.E Willard, D. A. Publication_Date: 2007 Title: Marl prairie vegetation response to 20th century hydrologic change Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: USGS Open-File Report Issue_Identification: 2006-1355 Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: http://pubs.er.usgs.gov/usgspubs/ofr/ofr20061355 Cross_Reference: Citation_Information: Originator: Willard, D. A. Cronin, T. M. Publication_Date: 2007 Title: Paleoecology and ecosystem restoration: case studies from Chesapeake Bay and the Florida Everglades Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Frontiers in Ecology and the Environment Issue_Identification: vol. 5, issue 9 Publication_Information: Publication_Place: ithica, NY Publisher: Ecological Society of America Other_Citation_Details: The full article is available via journal subscription or single article purchase. The abstract may be viewed at the URL below by selecting the article. Online_Linkage: http://www.esajournals.org/perlserv/?request=get-archive&issn=1540-9295&volume=5&issue=9 Cross_Reference: Citation_Information: Originator: Willard, D. A. Bernhardt, C. E.; Holmes, C. W.; Landacre, B.; Marot, M. Publication_Date: 2006 Title: Response of Everglades tree islands to environmental change Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Ecological Monographs Issue_Identification: v. 76, n. 4 Publication_Information: Publication_Place: Ithica, NY Publisher: Ecological Society of America Other_Citation_Details: The full article is available via journal subscription or single article purchase. The abstract may be viewed at the URL below by selecting the article. Online_Linkage: http://www.esajournals.org/perlserv/?request=get-toc&issn=0012-9615&volume=76&issue=4 Cross_Reference: Citation_Information: Originator: Langeland, K. Publication_Date: 1990 Title: Exotic Woody Plant Control Florida Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Circular Issue_Identification: 868 Publication_Information: Publication_Place: Florida Publisher: Florida Coooperative Extension Service Cross_Reference: Citation_Information: Originator: Flynn, W. W. Publication_Date: 1968 Title: The determination of low levels of polonium-210 in environmental materials Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Analytica Chimica Acta Issue_Identification: v. 43 Publication_Information: Publication_Place: Amsterdam, The Netherlands Publisher: Elsevier B. V. Other_Citation_Details: The abstract may be viewed online at the Science Direct website. The full article is available for purchase from the Science Direct website. Cross_Reference: Citation_Information: Originator: Stuiver, M. Reimer, P. J. Publication_Date: 1993 Title: Extended 14C database and revised CALIB 3.0 14C age calibration program Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Radiocarbon Issue_Identification: v. 35, n. 1 Cross_Reference: Citation_Information: Originator: Talma, A. S. Vogel, J. C. Publication_Date: 1993 Title: A simplified approach to calibrating C14 dates Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Radiocarbon Issue_Identification: v. 35, n. 2 Publication_Information: Publication_Place: Tucson, AZ Publisher: University of Arizona Cross_Reference: Citation_Information: Originator: Benninghoff, W. S. Publication_Date: 1962 Title: Calculation of pollen and spore density in sediments by addition of exotic pollen in known quantities Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Pollen et Spores Issue_Identification: v. 4 Publication_Information: Publication_Place: Paris, France Publisher: Museum national d'histoire naturelle Cross_Reference: Citation_Information: Originator: Maher, L. J., Jr Publication_Date: 1981 Title: Statistics for microfossil concentration measurements employing samples spiked with marker grains Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Review of Palaeobotany and Palynology Issue_Identification: v. 32, issues 2-3 Publication_Information: Publication_Place: Amsterdam, The Netherlands Publisher: Elsevier Science B. V. Other_Citation_Details: The full article is available via journal subscription or single article purchase. The abstract may be viewed on the Science Direct website by selecting the volume and issue number. Online_Linkage: http://www.sciencedirect.com/science/journal/00346667 Cross_Reference: Citation_Information: Originator: Stockmarr, J. Publication_Date: 1973 Title: Determination of spore concentration with an electronic particle counter Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Arbog Issue_Identification: v. 1972, p. 87-89 Publication_Information: Publication_Place: Copenhagen, Denmark Publisher: Danmarks Geologiske Undersogelse Cross_Reference: Citation_Information: Originator: Vogel, J. C. Fuls, A.; Visser, E,; Becker, B. Publication_Date: 1993 Title: Pretoria Calibration Curve for Short Lived Samples Geospatial_Data_Presentation_Form: report Series_Information: Series_Name: Radiocarbon Issue_Identification: v. 35, n. 1 Publication_Information: Publication_Place: Tucson, Arizona Publisher: University of Arizona Data_Quality_Information: Logical_Consistency_Report: not applicable Completeness_Report: Pollen data from surface samples collected during the 1960s: Column A (the sample ID) refers to the sites listing. Line 1 lists taxa identified in the samples. For lines 2-13, original raw data on total pollen grains were unavailable, so back-calculation from percentages to original counts was not possible. The numbers provided in these lines are percent abundances. For all other samples, the number of grains counted for each taxon was determined by back-calculation from percentages and total grains counted, as provided by Riegel, 1965. Pollen from surface sample collected in 1995 and 1998: Column A (sample ID) refers to the sites listing. Line 1 identifies taxa identified in the samples. Numbers provided for all taxa represent raw counts. Numbers of exotics counted refers to number of Lycopodium grains counted during each pollen count. For each sample, one tablet of Lycopodium grains was added before processing. Each tablet contains 12, 542 +/- 416 Lycopodium grains. Sample weight refers to the dry weight of sample processed. Pollen concentration (pollen grains/gram dry sediment) was calculated using the formula pollen grains/gram dry sediment= [(pollen counted/exotics counted) x 12542]/sediment weight Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Sampleing site locations were determined using GPS Lineage: Process_Step: Process_Description: Core Collection and Sampling We collected sediment cores using a piston corer with a 10 cm diameter core barrel. The core barrel was pushed through the sediments until it contacted the underlying limestone at all sites except in Loxahatchee NWR, where peat thicknesses in excess of 2 meters would require alternative coring strategies. After core collection, we extruded sediment from the core barrel and sampled it at 1 cm increments for the upper 20 cm and at 2 cm increments at greater depths. We described sediment lithology as samples were extruded. We dried samples in a 50 deg C oven and subsampled sediments at the base of each core and at 20 cm increments above the base for radiocarbon dating. Bulk peats were dated using conventional radiocarbon datin Process_Date: 1997 Process_Step: Process_Description: Geochronology Age models for the last century of deposition are based on 210Pb (lead-210) and, where applicable, first occurrences of pollen of the exotic plant Casuarina which was introduced to south Florida in the late 19th century (Langeland, 1990). Lead-210 (210Pb) activity was measured by alpha spectroscopy using the method outlined in Flynn (1968) in which 210Pb and its progeny, polonium-210 (210Po), are assumed to be in secular equilibrium. Supported 210Pb activity was determined by continuing measurements until activity became constant with depth. Excess 210Pb activity was calculated by subtracting the supported 210Pb activity from the total 210Pb activity. Accumulation rates were calculated by fitting an exponential decay curve to the measured data using least squares optimization and making the assumptions of a constant initial excess lead-210 concentration (the CIC [constant initial concentration] model) . In pre-20th century sediments, models are derived from linear interpolation between radiocarbon data points obtained on bulk sediment samples, which were calibrated to calendar years using the Pretoria Calibration Procedure (Stuiver et al., 1993; Talma and Vogel, 1993; Vogel et al., 1993). The shorter hydroperiods and shallower water depths on tree-island heads result in seasonal drying and oxidation of sediments. We have noted that radiocarbon dates from tree-island head sediments appear to be artificially old relative to those in the tail and adjacent marsh. Cores collected in the near tail, directly downstream from the head, have radiocarbon dates and vegetational trends that are consistent both internally and with adjacent wetlands. Therefore, we used cores from the near tail as our representative sites to detect vegetation changes on teardrop-shaped tree islands and for comparison with patterns documented in the adjacent marsh. Process_Date: 1997 Process_Step: Process_Description: Analysis of Pollen Assemblages Approximately 0.5-1.0 gram of dry sediment was used for palynological analysis. Pollen and spores were isolated from these samples using standard palynological techniques (Traverse, 1988; Willard et al, 2001a,b). After drying and weighing samples, Lycopodium marker tablets with known concentrations of Lycopodium spores were added to approximately 0.5 g of sediment for calculation of absolute pollen concentrations (Stockmarr, 1971). The samples were first acetolyzed (9 parts acetic anhydride : 1 part sulfuric acid) in a hot-water bath (100 deg C) for 10 minutes, then neutralized, and treated with 10% KOH in a hot-water bath for 15 minutes. Neutralized samples were sieved with 10 µm and 200 µm sieves, and the 10-200 µm fraction was stained with Bismarck Brown, mixed with warm glycerin jelly, and mounted on microscope slides. Raw data for pollen samples are reposited in the North American Pollen Database (NAPD) at the World Data Center for Paleoclimatology in Boulder, CO (http://www.ngdc.noaa.gov/paleo/pollen.html) and at the US Geological Survey South Florida Information Access (SOFIA) site (http://sofia.usgs.gov). Pollen and spore identification (minimally 300 grains per sample) was based on reference collections of the United States Geological Survey (Reston, VA) and Willard et al. (2004). Absolute pollen concentrations were calculated using the marker-grain method described by Benninghoff (1962). Marker tablets of Lycopodium spores were the source of the exotic grains, and the quantity of Lycopodium spores in the marker tablets was determined by the manufacturer with a Coulter Counter following the procedures of Stockmarr (1973). Absolute pollen concentration was calculated using the formula (Maher, 1981): Pconc=RM/V, Where: Pconc = pollen per gram dry sediment; R=pollen grains counted/marker grains counted; M=marker grains added; V=dry weight of sediment Our interpretations of past plant communities are based on the quantitative method of modern analogs (Overpeck et al., 1985). We calculated squared chord distance (SCD) between down-core pollen assemblages and a suite of 197 surface samples collected throughout southern Florida in the early 1960s and 1995-2002 (Willard et al., 2001b and this research) to define the similarity between each fossil and modern pollen assemblage. Internal comparison among surface samples from ten vegetation types indicates that samples with SCD values < 0.15 may be considered close analogs (Willard et al., 2001b). If analogs were present for a fossil assemblage, we identified the source vegetation for the fossil assemblage as one of the twelve types represented in the modern database. We divided cores into pollen zones based on a combination of visual inspection, objective zonation using CONISS (Grimm, 1992), and modern analogs. Process_Date: 2007 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Debra A Willard Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: 926A National Center City: Reston State_or_Province: VA Postal_Code: 20192 Contact_Voice_Telephone: 703 648 5320 Contact_Facsimile_Telephone: 703 648 6953 Contact_Electronic_Mail_Address: dwillard@usgs.gov Spatial_Data_Organization_Information: Indirect_Spatial_Reference: Everglades tree islands, Ridge and Slough system, marl prairies Direct_Spatial_Reference_Method: Point Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Point Point_and_Vector_Object_Count: 209 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.1 Longitude_Resolution: 0.1 Geographic_Coordinate_Units: Degrees, minutes, and decimal seconds Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298.257 Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: The data for each collection site include the sample id and raw abundance data for each species identified. In the 1960s dataset, raw abundance was back-calculated from percentage data because original raw data was unavailable. The data for the 1990s dataset include the sample number and map ID and percent abundance for each species. See the individual datasets for the species found at the sites. Entity_and_Attribute_Detail_Citation: USGS personnel Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Heather S.Henkel Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: 600 Fourth St. South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727 803-8747 ext 3028 Contact_Facsimile_Telephone: 727 803-2030 Contact_Electronic_Mail_Address: hhenkel@usgs.gov Resource_Description: South Florida pollen data Distribution_Liability: The data have no implied or explicit guarantees Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: MS Excel Format_Version_Number: unknown Format_Information_Content: Each file contains data for a specific time period Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://sofia.usgs.gov/exchange/willard/willardsflpollen.html Access_Instructions: Excel files for pollen data from the 1960's and 1990's, 2001 and 2002 are available from the SOFIA website. Fees: none Metadata_Reference_Information: Metadata_Date: 20080428 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Heather Henkel Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing and physical address Address: 600 Fourth Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727 803-8747 ext 3028 Contact_Facsimile_Telephone: 727 803-2030 Contact_Electronic_Mail_Address: sofia-metadata@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998