Debra A Willard, Ph.D.
I am a palynologist (pollen and spores) with expertise in paleoecology, paleoclimatology, and biostratigraphy. My biostratigraphic expertise extends from the Carboniferous to the Holocene, with an emphasis on Euramerica (Paleozoic) and the Northern Hemisphere. My paleoclimate expertise includes the late Paleozoic and the Paleogene to Holocene intervals.
Editorial Boards
- Global and Planetary Change
- Frontiers in Ecology and Evolution – Paleoecology section Review Editor
- Quaternary
- Review of Palaeobotany and Palynology
Professional Experience
2021-Present Research Geologist, US Geological Survey, Reston, Virginia
2011-2021 Coordinator, USGS Climate Research & Development Program
1991-2011 Research Geologist, US Geological Survey, Reston, Virginia
1990-1991 Postdoctoral Researcher, National Museum of Natural History, Smithsonian Institution, Washington, DC
Education and Certifications
University of Illinois at Urbana-Champaign - Ph.D., Botany 1990
University of Illinois at Urbana-Champaign - M.S., Botany 1985
The Pennsylvania State University - B.S., Botany 1982
Stephens College - A.A., Geology 1980
Affiliations and Memberships*
American Geophysical Union
Geological Society of America
The Palynological Society
Science and Products
Effects of climate variability and human activities on Chesapeake Bay and the implications for ecosystem restoration
Climatic variability in the eastern United States over the past millennium from Chesapeake Bay sediments
Historical trends in Chesapeake Bay dissolved oxygen based on benthic foraminifera from sediment cores
Middle Pliocene paleoenvironmental reconstruction; PRISM2
Preliminary paleontologic report on core 37 from Pass Key, Everglades National Park, Florida Bay
A record of ecosystem change, Manatee Bay, Barnes Sound, Florida
Phanerozoic stratigraphy of Northwind Ridge, magnetic anomalies in the Canada Basin, and the geometry and timing of rifting in the Amerasia Basin, Arctic Ocean
Preliminary paleontologic report on cores 19A and 19B, from Russell Bank, Everglades National Park, Florida Bay
Pollen and geochronological data from South Florida; Taylor Creek Site 2
Two new species of Scolecopteris (Marattiales), sources of Torispora securis Balme and Thymospora thiessenii (Kosanke) Wilson et Venkatachala
Paleontological data from Mud Creek Core 1, southern Florida
Palynological census data from surface samples in south Florida
Science and Products
- Science
- Data
- Multimedia
- Publications
Filter Total Items: 100
Effects of climate variability and human activities on Chesapeake Bay and the implications for ecosystem restoration
Chesapeake Bay, the Nation’s largest and most productive estuary (fig. 1), faces complex environmental issues related to nutrients and oxygen, turbidity and sedimentation, toxic dinoflagellates, sea-level rise, and coastal erosion. The Chesapeake Bay Program (CBP) is a partnership among the Chesapeake Bay Commission, the Federal Government, the District of Columbia, and the States of Maryland, VirAuthorsThomas M. Cronin, Debra A. Willard, Scott PhillipsClimatic variability in the eastern United States over the past millennium from Chesapeake Bay sediments
Salinity oscillations caused by multidecadal climatic variability had major impacts on the Chesapeake Bay estuarine ecosystem during the past 1000 yr. Microfossils from sediments dated by radiometry (14C, 137Cs, 210Pb) and pollen stratigraphy indicate that salinity in mesohaline regions oscillated 10-15 ppt during periods of extreme drought (low fresh-water discharge) and wet climate (high discharAuthorsThomas M. Cronin, Debra A. Willard, A. Karlsen, S. Ishman, S. Verardo, John McGeehin, R. Kerhin, C. Holmes, S. Colman, A. ZimmermanHistorical trends in Chesapeake Bay dissolved oxygen based on benthic foraminifera from sediment cores
Environmentally sensitive benthic foraminifera (protists) from Chesapeake Bay were used as bioindicators to estimate the timing and degree of changes in dissolved oxygen (DO) over the past five centuries. Living foraminifers from 19 surface samples and fossil assemblages from 11 sediment cores dated by210Pb,137Cs,14C, and pollen stratigraphy were analyzed from the tidal portions of the Patuxent, PAuthorsA.W. Karlsen, T. M. Cronin, S.E. Ishmans, D. A. Willard, R. Kerhin, C. W. Holmes, M. MarotMiddle Pliocene paleoenvironmental reconstruction; PRISM2
No abstract available.AuthorsH.J. Dowsett, J.A. Barron, R. Z. Poore, R.S. Thompson, T. M. Cronin, S. E. Ishman, D. A. WillardPreliminary paleontologic report on core 37 from Pass Key, Everglades National Park, Florida Bay
Sediments from Pass Key core 37, in eastern Florida Bay (N 25.1478, W 80.5745) record a history of rapid sedimentation during this century. The lowest portion of the core contains benthic fauna indicative of relatively low salinities and sparse seagrass coverage. This period is followed by an increase in salinity and seagrass. In the middle portion of the core, a slight decrease in salinity and anAuthorsG. L. Brewster-Wingard, S. E. Ishman, N.J. Waibel, Debra A. Willard, Lucy E. Edwards, C. W. HolmesA record of ecosystem change, Manatee Bay, Barnes Sound, Florida
No abstract available.AuthorsScott E. Ishman, Thomas M. Cronin, G. Lynn Brewster-Wingard, Debra A. Willard, David J. VerardoPhanerozoic stratigraphy of Northwind Ridge, magnetic anomalies in the Canada Basin, and the geometry and timing of rifting in the Amerasia Basin, Arctic Ocean
Cores from Northwind Ridge, a high-standing continental fragment in the Chukchi borderland of the oceanic Amerasia basin, Arctic Ocean, contain representatives of every Phanerozoic system except the Silurian and Devonian systems.Cambrian and Ordovician shallow-water marine carbonates in Northwind Ridge are similar to basement rocks beneath the Sverdrup basin of the Canadian Arctic Archipelago. UppAuthorsA. Grantz, D.L. Clark, R. L. Phillips, S.P. Srivastava, C.D. Blome, L.-B. Gray, H. Haga, B. L. Mamet, D.J. McIntyre, D. H. McNeil, M.B. Mickey, M. W. Mullen, B.I. Murchey, C.A. Ross, C. H. Stevens, Norman J. Silberling, J.H. Wall, D. A. WillardPreliminary paleontologic report on cores 19A and 19B, from Russell Bank, Everglades National Park, Florida Bay
The fauna and flora preserved in two cores, 19A and 19B, from the south side of Russell Bank (N 25 03.831', W 80 37.486') in north-central Florida Bay, Everglades National Park, Florida, record a history of environmental change over the last century. The benthic foraminifera and molluscs indicate fluctuating salinities with increasing average salinity upcore in core 19B. Shifts from low salinity (AuthorsG. L. Brewster-Wingard, S. E. Ishman, D. A. Willard, Lucy E. Edwards, C. W. HolmesPollen and geochronological data from South Florida; Taylor Creek Site 2
Many recent changes in plant and animal communities of the Everglades have been attributed to human alteration of the environment, such as changes in the hydrologic regime and increased agricultural activity, but cause-and-effect relationships between environmental and biotic changes have not been documented scientifically. This report on pollen and geochronological evidence from cores collected aAuthorsD. A. Willard, C. W. HolmesTwo new species of Scolecopteris (Marattiales), sources of Torispora securis Balme and Thymospora thiessenii (Kosanke) Wilson et Venkatachala
Two biostratigraphically significant miospore species, Thymospora thiessenii and Torispora securis, were isolated from marattialean synangia preserved in coal-ball permineralizations from Pennsylvanian strata of the Illinois Basin and Western Interior coal region. Synangia containing Thymospora thiessenii were recovered from the Missourian Parker Coal Member (Patoka Formation) of Indiana and are dAuthorsAlicia D. Lesnikowska, Debra A. WillardPaleontological data from Mud Creek Core 1, southern Florida
No abstract available.AuthorsD. A. Willard, G. L. Brewster-Wingard, Claire Fellman, S. E. IshmanPalynological census data from surface samples in south Florida
No abstract available.AuthorsD. A. Willard, L. M. Weimer - News
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government