Debra A. Willard
2006
Ecosystem History: Terrestrial and Fresh-Water Ecosystems of southern Florida
spreadsheet
http://sofia.usgs.gov/projects/eh_fleco/
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).
This project is designed to document the terrestrial ecosystem history of south Florida and is collaborating with other projects at the USGS and other agencies on Florida Bay, Biscayne Bay, and the Buttonwood Embankment. The specific goals of the project are 1) document the patterns of floral and faunal change at sites throughout southern Florida over the last 150 years; 2) determine whether changes occurred throughout the entire region or whether they were localized; 3) examine the floral and faunal history of the region over the last few millennia; 4) determine the baseline level of variability in the communities prior to significant human activity in the region; and 5) determine whether the fire frequency, extent, and influence can be quantified, and if so, document the fire history for sites in the region. Data generated from this project will be integrated with data from other projects to provide biotic reconstructions for the area at selected time slices and will be useful in testing ecological models designed to predict floral and faunal response to changes in environmental parameters.
1994
2007
ground condition
as needed
-81.83
-80.3
26.5
25
none
ecosystem history
vegetational history
palynology
pollen analysis
charcoal
biology
geology
ecology
marl prairies
sawgrass ridge
slough
ridge and slough landscape
ISO 19115 Topic Category
environment
geoscientificInformation
inlandWaters
007
008
012
Department of Commerce, 1995, Countries, Dependencies, Areas of Special Sovereignty, and Their Principal Administrative Divisions, Federal Information Processing Standard (FIPS) 10-4, Washington, D.C., National Institute of Standards and Technology
United States
US
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, D. C., NIST
Florida
FL
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
Collier County
Broward County
Palm Beach County
Miami-Dade County
Monroe County
USGS Geographic Names Information System
Everglades National Park
Big Cypress National Preserve
Florida Bay
Manatee Bay
Pass Key
Biscayne Bay
none
Central Everglades
South East Coast
SW Big Cypress
WCA1
WCA2
WCA3
Water Conservation Area 1
Water Conservation Area 2
Water Conservation Area 3
Taylor Creek
Russell Bank
none
surficial peat/soil/sediment
none
None. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data.
Debra A Willard
U.S. Geological Survey
mailing address
926A National Center
Reston
VA
20192
703 648 5320
703 648 6953
dwillard@usgs.gov
http://sofia.usgs.gov/exchange/willard/pollendata-map.gif
map showing surface sample locations for the 1960's, 1995, & 1998
GIF
http://sofia.usgs.gov/exchange/willard/Willardetal2001sitemapx.gif
map showing 2001 sample site localities
GIF
http://sofia.usgs.gov/exchange/willard/Willardetal2002sitemapx.gif
map showing 2002 sample site locations
GIF
http://sofia.usgs.gov/exchange/willard/EvergladesCoreMap5-07x.jpg
map showing all cores collected through 2007
JPEG
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.
Analyses were done using Macintosh-based software. Data are stored as Excel spreadsheets
Willard, Debra A.
Weimer, Lisa M.
1997
Palynological Census Data from Surface Samples in South Florida
report
USGS Open-File Report
97-0867
Reston, VA
U.S. Geological Survey
http://pubs.usgs.gov/pdf/of/ofr97867.html
Willard, Debra A.
1997
Pollen Census Data from Southern Florida: Sites Along an Nutrient Gradient in Water Conservation Area 2A
report
USGS Open-File Report
97-0497
Reston, VA
U.S. Geological Survey
http://pubs.usgs.gov/pdf/of/ofr97497.html
Willard, Debra A.
Bernhardt, Christopher E.;
Weimer, Lisa (deceased);
Gamez, Desire;
Cooper, Sherri R.;
Jensen, Jennifer
2004
Atlas of Pollen and Spores of the Florida Everglades
report
Palynology
28
Arlington, TX
American Association of Stratigraphic Palynologists
Posted with permission from Palynology and the American Association of Stratigraphic Palynologists
http://sofia.usgs.gov/publications/papers/pollen_atlas/
Marshall, Curtis H.
Pielke, Roger A., Sr.;
Steyaert, Louis T.;
Willard, Debra A.
200401
The Impact of Anthropogenic Land-Cover Change on the Florida Peninsula Sea Breezes and Warm Season Sensible Weather
report
Monthly Weather Review
v. 132, n. 1
Boston, MA
American Meterological Society
Permission to post a copy of this work on the SOFIA server has been provided by the American Meterological Society
http://sofia.usgs.gov/publications/papers/cover_weather/
Willard, Debra A.
Weimer, Lisa M.;
Riegel, W. L.
2001
Pollen assemblages as paleoenvironmental proxies in the Florida Everglades
report
Review of Palaeobotany and Palynology
v. 113, n. 4
Amsterdam, The Netherlands
Elsevier Science B.V.
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.
http://www.sciencedirect.com/science/journal/00346667
Willard, D. A.
Holmes, C. W.;
Korvela, M. S.;
Mason, D.;
Murray, J. B.;
Orem, W. H.;
Towles, T.
200302
Paleoecological Insights on Fixed Tree Island Development in the Florida Everglades: I. Environmental Controls
book chapter
Dordrecht, Netherlands
Kluwer Academic Publishers
in Tree Islands of the Everglades
Sklar, F. H. and van der Valk A. (editors)
http://sofia.usgs.gov/sfrsf/rooms/wild_wet_eco/tree_islands/index.html
Willard, D. A.
Orem, W. H.
2003
Tree Islands of the Florida Everglades - A Disappearing Resource
report
U.SGS Open-File Report
03-26
Reston, VA
U.S. Geological Survey
http://sofia.usgs.gov/publications/ofr/03-26/
Bernhardt, C. E.
Willard, D. A.;
Marot, M.;
Holmes, C. W.
2004
Anthropogenic and natural variation in Ridge and Slough pollen assemblages
report
USGS Open-File Report
2004-1448
Reston, VA
U.S. Geological Survey
http://sofia.usgs.gov/publications/ofr/2004-1448/
Willard, D. A.
Holmes, C. W.;
Weimer, L. M.
2001
The Florida Everglades Ecosystem: Climatic and Anthropogenic Impacts over the Last Two Millenia
paper
Bulletins of American Paleontology
v. 361
Ithica, NY
Paleontological Research Institute
in Paleoecology of South Florida, B. R. Wardlaw, ed.
Grimm, E. C.
1992
CONISS: a Fortran 77 program for stratigraphically constrained cluster analysis by the mothod of incremental sum of squares
paper
Computers & Geosciences
v. 13, issue 1
Amsterdam, The Netherlands
Elsevier Science, Ltd.
The abstract may be viewed online at the Science Direct website. The full article is available for purchase from the Science Direct website.
http://www.sciencedirect.com/science/journal/00983004
Traverse, A.
1988
Paleopalynology
book
Boston, MA
Unwin Hyman
Stockmarr, J.
1971
Tablets with spores used in absolute pollen analysis
report
Pollen et Spores
v. 13
Paris, France
Museum national d'histoire naturelle
Overpeck, J. T.
Webb, III, T.;
Prentice, I. C.
1985
Quantitative interpretation of fossil pollen spectra: Dissimilarity coefficients and the method of modern analogs
report
Quaternary Research
v 23, issue 1
Amsterdam, Netherlands
Elsevier Science, Ltd.
The abstract may be viewed online at the Science Direct website. The full article is available for purchase from the Science Direct website.
http://www.sciencedirect.com/science/journal/00335894
Willard, D. A.
2004
Tree Islands of the Florida Everglades - Long-term stability and response to hydrologic change
factsheet
USGS Fact Sheet
2004-3095
Reston, VA
U.S. Geological Survey
http://pubs.usgs.gov/fs/2004/3095
Bernhardt, C.E
Willard, D. A.
2007
Marl prairie vegetation response to 20th century hydrologic change
report
USGS Open-File Report
2006-1355
Reston, VA
U.S. Geological Survey
http://pubs.er.usgs.gov/usgspubs/ofr/ofr20061355
Willard, D. A.
Cronin, T. M.
2007
Paleoecology and ecosystem restoration: case studies from Chesapeake Bay and the Florida Everglades
report
Frontiers in Ecology and the Environment
vol. 5, issue 9
ithica, NY
Ecological Society of America
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.
http://www.esajournals.org/perlserv/?request=get-archive&issn=1540-9295&volume=5&issue=9
Willard, D. A.
Bernhardt, C. E.;
Holmes, C. W.;
Landacre, B.;
Marot, M.
2006
Response of Everglades tree islands to environmental change
report
Ecological Monographs
v. 76, n. 4
Ithica, NY
Ecological Society of America
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.
http://www.esajournals.org/perlserv/?request=get-toc&issn=0012-9615&volume=76&issue=4
Langeland, K.
1990
Exotic Woody Plant Control Florida
report
Circular
868
Florida
Florida Coooperative Extension Service
Flynn, W. W.
1968
The determination of low levels of polonium-210 in environmental materials
report
Analytica Chimica Acta
v. 43
Amsterdam, The Netherlands
Elsevier B. V.
The abstract may be viewed online at the Science Direct website. The full article is available for purchase from the Science Direct website.
Stuiver, M.
Reimer, P. J.
1993
Extended 14C database and revised CALIB 3.0 14C age calibration program
report
Radiocarbon
v. 35, n. 1
Talma, A. S.
Vogel, J. C.
1993
A simplified approach to calibrating C14 dates
report
Radiocarbon
v. 35, n. 2
Tucson, AZ
University of Arizona
Benninghoff, W. S.
1962
Calculation of pollen and spore density in sediments by addition of exotic pollen in known quantities
report
Pollen et Spores
v. 4
Paris, France
Museum national d'histoire naturelle
Maher, L. J., Jr
1981
Statistics for microfossil concentration measurements employing samples spiked with marker grains
report
Review of Palaeobotany and Palynology
v. 32, issues 2-3
Amsterdam, The Netherlands
Elsevier Science B. V.
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.
http://www.sciencedirect.com/science/journal/00346667
Stockmarr, J.
1973
Determination of spore concentration with an electronic particle counter
report
Arbog
v. 1972, p. 87-89
Copenhagen, Denmark
Danmarks Geologiske Undersogelse
Vogel, J. C.
Fuls, A.;
Visser, E,;
Becker, B.
1993
Pretoria Calibration Curve for Short Lived Samples
report
Radiocarbon
v. 35, n. 1
Tucson, Arizona
University of Arizona
All cores were taken using the same techniques
The cores were selected for analysis based on x-rays taken of the cores. Those cores selected for further analysis were selected on the basis of laminations or other features which indicated a lack of disturbance.
The locations of the sampling sites were established by GPS.
Coring Procedure
Sediment cores were collected 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, sediment was extruded from the core barrel and sampled it at 1 cm increments for the upper 20 cm and at 2 cm increments at greater depths. Sediment lithology was described as samples were extruded. Samples were dried 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 dating
1997
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.
1997
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.
2007
Debra A Willard
U.S. Geological Survey
mailing address
926A National Center
Reston
VA
20192
703 648 5320
703 648 6953
dwillard@usgs.gov
South Florida
Point
Point
209
0.001
0.001
Degrees and decimal minutes
North American Datum of 1983
Geodetic Reference System 80
6378137
298.257
For the Florida and Biscayne Bays Pollen Data each dataset contains the pollen concentration by species and depth in the core.
For the South Florida Pollen Data 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.
USGS personnel
Heather S.Henkel
U.S. Geological Survey
mailing address
600 Fourth St. South
St. Petersburg
FL
33701
USA
727 803-8747 ext 3028
727 803-2030
hhenkel@usgs.gov
South Florida pollen data
The data have no implied or explicit guarantees
MS Excel
unknown
Each file contains data for a specific time period
http://sofia.usgs.gov/exchange/willard/willardsflpollen.html
Excel files for pollen data from the 1960's and 1990's, 2001 and 2002 are available from the SOFIA website.
none
Heather S.Henkel
U.S. Geological Survey
mailing address
600 Fourth St. South
St. Petersburg
FL
33701
USA
727 803-8747 ext 3028
727 803-2030
hhenkel@usgs.gov
Florida and Biscayne Bays Pollen Data
The data have no implied or explicit guarantees
MS Excel
unknown
Pollen data is available as a separate spreadsheet for individual sample sites
http://sofia.usgs.gov/exchange/willard/willardpollen.html
Data may be downloaded from the SOFIA website
none
20080428
Heather Henkel
U.S. Geological Survey
mailing and physical address
600 Fourth Street South
St. Petersburg
FL
33701
USA
727 803-8747 ext 3028
727 803-2030
sofia-metadata@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998