Debra A Willard, Ph.D.
I am a palynologist (pollen and spores) with expertise in paleoecology and biostratigraphy. My biostratigraphic expertise extends from the Carboniferous to the Holocene, with an emphasis on Euramerica (Paleozoic) and the Northern Hemisphere. My paleoecological 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 Land Change Science 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
Filter Total Items: 101
The Medieval Climate Anomaly and Little Ice Age in Chesapeake Bay and the North Atlantic Ocean
A new 2400-year paleoclimate reconstruction from Chesapeake Bay (CB) (eastern US) was compared to other paleoclimate records in the North Atlantic region to evaluate climate variability during the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA). Using Mg/Ca ratios from ostracodes and oxygen isotopes from benthic foraminifera as proxies for temperature and precipitation-driven...
Authors
T. M. Cronin, Kathryn Hayo, R.C. Thunell, G. S. Dwyer, Casey Saenger, Debra A. Willard
Millennial-scale variability during the last glacial in vegetation records from North America
High-resolution pollen records from North America show that terrestrial environments were affected by Dansgaard-Oeschger (D-O) and Heinrich climate variability during the last glacial. In the western, more mountainous regions, these climate changes are generally observed in the pollen records as altitudinal movements of climate-sensitive plant species, whereas in the southeast, they are...
Authors
Gonzalo Jimenez-Moreno, R. Todd Anderson, S. Desprat, L.D. Grigg, E.C. Grimm, Linda E. Heusser, Brian F. Jacobs, C. Lopez-Martinez, C.L. Whitlock, Debra A. Willard
Response of the everglades ridge and slough landscape to climate variability and 20th-century water management
The ridge and slough landscape of the Florida Everglades consists of a mosaic of linear sawgrass ridges separated by deeper-water sloughs with tree islands interspersed throughout the landscape. We used pollen assemblages from transects of sediment cores spanning sawgrass ridges, sloughs, and ridge-slough transition zones to determine the timing of ridge and slough formation and to...
Authors
C.E. Bernhardt, Debra A. Willard
A Holocene record of climate-driven shifts in coastal carbon sequestration
A sediment core collected in the mesohaline portion of Chesapeake Bay was found to contain periods of increased delivery of refractory black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs). The BC was most likely produced by biomass combustion during four centennialscale dry periods as indicated by the Palmer Drought Severity Index (PDSI), beginning in the late Medieval Warm...
Authors
Siddhartha Mitra, A.R. Zimmerman, G.B. Hunsinger, Debra A. Willard, J.C. Dunn
Mid-Cenozoic tectonic and paleoenvironmental setting of the central Arctic Ocean
Drilling results from the Integrated Ocean Drilling Program's Arctic Coring Expedition (ACEX) to the Lomonosov Ridge (LR) document a 26 million year hiatus that separates freshwater-influenced biosilica-rich deposits of the middle Eocene from fossil-poor glaciomarine silty clays of the early Miocene. Detailed micropaleontological and sedimentological data from sediments surrounding this...
Authors
M. O'Regan, K. Moran, J. Backman, M. Jakobsson, Francesca Sangiorgi, Henk Brinkhuis, Robert Pockalny, Alasdair Skelton, Catherine E. Stickley, Nalan Koc, Hans-Juergen Brumsack, Debra A. Willard
Impacts of post-glacial lake drainage events and revised chronology of the Champlain Sea episode 13-9 ka
Lithologic, CHIRP (Compressed High Intensity Radar Pulse) sonar, paleomagnetic, stable isotopic and micropaleontological analyses of sediment cores from Lake Champlain (New York, Vermont) were used to determine the age of the post-glacial Champlain Sea marine episode, the timing of salinity changes and their relationship to freshwater discharge from mid-continent glacial lakes...
Authors
T. M. Cronin, P.L. Manley, S. Brachfeld, T.O. Manley, Debra A. Willard, J.-P. Guilbault, J.A. Rayburn, R. Thunell, M. Berke
Science and Products
Filter Total Items: 101
The Medieval Climate Anomaly and Little Ice Age in Chesapeake Bay and the North Atlantic Ocean
A new 2400-year paleoclimate reconstruction from Chesapeake Bay (CB) (eastern US) was compared to other paleoclimate records in the North Atlantic region to evaluate climate variability during the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA). Using Mg/Ca ratios from ostracodes and oxygen isotopes from benthic foraminifera as proxies for temperature and precipitation-driven...
Authors
T. M. Cronin, Kathryn Hayo, R.C. Thunell, G. S. Dwyer, Casey Saenger, Debra A. Willard
Millennial-scale variability during the last glacial in vegetation records from North America
High-resolution pollen records from North America show that terrestrial environments were affected by Dansgaard-Oeschger (D-O) and Heinrich climate variability during the last glacial. In the western, more mountainous regions, these climate changes are generally observed in the pollen records as altitudinal movements of climate-sensitive plant species, whereas in the southeast, they are...
Authors
Gonzalo Jimenez-Moreno, R. Todd Anderson, S. Desprat, L.D. Grigg, E.C. Grimm, Linda E. Heusser, Brian F. Jacobs, C. Lopez-Martinez, C.L. Whitlock, Debra A. Willard
Response of the everglades ridge and slough landscape to climate variability and 20th-century water management
The ridge and slough landscape of the Florida Everglades consists of a mosaic of linear sawgrass ridges separated by deeper-water sloughs with tree islands interspersed throughout the landscape. We used pollen assemblages from transects of sediment cores spanning sawgrass ridges, sloughs, and ridge-slough transition zones to determine the timing of ridge and slough formation and to...
Authors
C.E. Bernhardt, Debra A. Willard
A Holocene record of climate-driven shifts in coastal carbon sequestration
A sediment core collected in the mesohaline portion of Chesapeake Bay was found to contain periods of increased delivery of refractory black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs). The BC was most likely produced by biomass combustion during four centennialscale dry periods as indicated by the Palmer Drought Severity Index (PDSI), beginning in the late Medieval Warm...
Authors
Siddhartha Mitra, A.R. Zimmerman, G.B. Hunsinger, Debra A. Willard, J.C. Dunn
Mid-Cenozoic tectonic and paleoenvironmental setting of the central Arctic Ocean
Drilling results from the Integrated Ocean Drilling Program's Arctic Coring Expedition (ACEX) to the Lomonosov Ridge (LR) document a 26 million year hiatus that separates freshwater-influenced biosilica-rich deposits of the middle Eocene from fossil-poor glaciomarine silty clays of the early Miocene. Detailed micropaleontological and sedimentological data from sediments surrounding this...
Authors
M. O'Regan, K. Moran, J. Backman, M. Jakobsson, Francesca Sangiorgi, Henk Brinkhuis, Robert Pockalny, Alasdair Skelton, Catherine E. Stickley, Nalan Koc, Hans-Juergen Brumsack, Debra A. Willard
Impacts of post-glacial lake drainage events and revised chronology of the Champlain Sea episode 13-9 ka
Lithologic, CHIRP (Compressed High Intensity Radar Pulse) sonar, paleomagnetic, stable isotopic and micropaleontological analyses of sediment cores from Lake Champlain (New York, Vermont) were used to determine the age of the post-glacial Champlain Sea marine episode, the timing of salinity changes and their relationship to freshwater discharge from mid-continent glacial lakes...
Authors
T. M. Cronin, P.L. Manley, S. Brachfeld, T.O. Manley, Debra A. Willard, J.-P. Guilbault, J.A. Rayburn, R. Thunell, M. Berke
*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