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Debra Willard

Coordinator, Climate and Land Use Change Research & Development Program

Contact Info

Short Biography



1982            BS (Biology)            The Pennsylvania State University

1985            MS (Botany)            University of Illinois at Urbana-Champaign

1990            PhD (Botany)           University of Illinois at Urbana-Champaign


Professional Experience:


1990 - 1991            Postdoctoral Fellow, National Museum of Natural History, Smithsonian Institution – Morphometric and phylogenetic analysis of Carboniferous lycopsids; Palynological analysis of Carboniferous coals


1991 – 2011            Research Geologist, U.S. Geological Survey

                                                 - Project Chief on projects dealing with Everglades Ecosystem History, Atlantic Estuaries, and Climate Variability of the Southeastern US; Project Member on PRISM – global reconstruction of mid-Pliocene climate from 1991-1995.                                         


2011 – Present         Coordinator, Climate and Land Use Change Research & Development Program

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Shah, Anjana K., Vogt, Peter, Rosenbaum, Joseph G., Newell, Wayne, Cronin, Thomas M., Willard, Debra A., Hagen, Richard, Brazena, John, and Hofstra, Albert. 2012 (in press).  Shipboard magnetic field “noise” reveals shallow heavy mineral sediment concentrations in Chesapeake Bay.  Marine Geology.


Willard, Debra A. and Bernhardt, Christopher E., 2011. Impacts of past climate and sea level change on Everglades wetlands: placing a century of anthropogenic change into a late-Holocene context.  Climatic Change 107: 59-80.doi:10.1007/s10584-011-0078-9


Willard, Debra A., Bernhardt, Christopher E., Brown, Roger, Landacre, Bryan, and Townsend, Philip, 2011. Development and application of a pollen-based paleohydrologic reconstruction from the Lower Roanoke River Basin, North Carolina, USA. The Holocene 21: 305-317. doi: 10.1177/0959683610378876


Culver, Stephen J., Farrell, Kathleen M., Mallinson, David J., Willard, Debra A., Horton, Benjamin P., Riggs, Stanley R., Thieler, E. Robert, Wehmiller, John F., Parham, Peter, Snyder, Scott W., and Hillier, Caroline, 2011. Micropaleontologic record of Quaternary paleoenvironments in the Central Albemarle Embayment, North Carolina, U.S.A.  Palaeogeography, Palaeoclimatology, Palaeoecology 305:  227-245.


Rayburn, John A., Cronin, Thomas M., Franzi, David A., Knuepfer, Peter L.K., and Willard, Debra A., 2011.  Timing and duration of North American glacial lake discharges and the Younger Dryas climate reversal.  Quaternary Research 75: 541-551.


Jiménez-Moreno, G., Anderson, R.S., Desprat, S., Grigg, L.D., Grimm, E.C., Heusser, L.E., Jacobs, B.F., López-Martínez, C., Whitlock, C., Willard, D.A., 2010.  Millennial-scale variability during the last glacial in vegetation records from North America.  Quaternary Science Reviews



Murray, James B., Wingard, G. Lynn, Cronin, Thomas M., Orem, William H., Willard, Debra A., Holmes, Charles W., Reich, Christopher, Shinn, Eugene, Marot, Marci, Lerch, Terry, Trappe, Carleigh, and Landacre, Bryan.  2010. Evidence of Environmental Change in Rankin Basin, Central Florida Bay, Everglades National Park.  USGS Open File Report 2010-1125: 1-54.


Bernhardt, C.E. and Willard, D.A., 2009.  Response of the Everglades sawgrass ridge and slough landscape to late Holocene climate variability and 20th century water-management practices.  Ecological Applications, 19, p. 1723-1738. doi:


Mitra, Siddhartha, Zimmerman, Andrew R., Hunsinger, Glendon B., Willard, Debra, and Dunn, Joshua C., 2009. A Holocene record of climate-driven shifts in coastal carbon sequestration.   Geophysical Research Letters, v. 36, L05704. doi:10.1029/2008GL036875


Saenger, Casey, Cronin, Thomas M., Willard, Debra A., Halka, Jeffrey, and Kerhin, Randy, 2008. Increased Terrestrial to Ocean Sediment and Carbon Fluxes in the Northern Chesapeake Bay Associated With Twentieth Century Land Alteration.  Estuaries and Coasts 31:  491-500. doi: 10.1007/s12237-008-9048-5


Culver, Stephen J., Farrell, Kathleen M., Mallinson, David J., Horton, Benjamin P., Willard, Debra A., Thieler, E. Robert, Riggs, Stanley R., Snyder, Scott W., Wehmiller, John F., Bernhardt, Christopher E., and Hillier, Caroline, 2008. Micropaleontologic record of late Pliocene and Quaternary paleoenvironments in the northern Albemarle Embayment, North Carolina, U.S.A. Palaeogeography, Palaeoclimatology, Palaeoecology 264: 54-77. doi:10.1016/j.palaeo.2008.03.012

O’Regan, M., Moran, K., Backman, J., Jakobsson, M., Sangiorgi, F., Brinkhuis, H., Pockalny, R., Skelton, A., Stickley, C., Koç, N., Brumsack, H-J, and Willard, D.  2008.  Mid-Cenozoic tectonic and paleoenvironmental setting of the central Arctic Ocean. Paleoceanography, 23, PA1S20, doi:10.1029/2007PA001559.


Sangiorgi, F., Brumsack, H-J, Willard, D.A., Schouten, S., Stickley, C.E., O’Regan, M., Reichart, G-J, Sinninghe Damsté, J.S., and Brinkhuis, H., 2008.  A 26 million year gap in the central Arctic record at the greenhouse-icehouse transition:  looking for clues.  Paleoceanography 23, PA1S04, doi:10.1029/2007PA001477.


Cronin, T.M., Manley, P.L., Brachfeld, S., Manley, T.O., Willard, D.A., Guilbault, J-P, Rayburn, J.A., Thunell, R., and Berke, M., 2008.  Impacts of post-glacial lake drainage events and revised chronology of the Champlain Sea episode 13-9 ka.  Palaeogeography, Palaeoclimatology, Palaeoecology, 262:  46-60.


Cronin, T.M., Edgar, N.T., Brooks, G., Hastings, D., Larson, R., Hine, A., Locker, S., Suthard, B., Flower, B., Hollander, D., Wehmiller, J., Willard, D., and Smith, S., 2007.  Sea level rise in Tampa Bay, Eos Transactions AGU, 88, doi:10.1029/2007EO100002.


Willard, Debra A. and Cronin, Thomas M., 2007.  Paleoecology and ecosystem restoration:  case studies from Chesapeake Bay and the Florida Everglades.  Frontiers in Ecology and the Environment 5: 491-498. doi:10.1890/070015


Willard, D.A., Bernhardt, C.E., Brooks, G.R., Cronin, T., Edgar, T., and Larson, R., 2007.  Deglacial climate variability in central Florida, USA.  Palaeogeography, Palaeoclimatology, Palaeoecology, v. 251, p. 366-382.


Wingard, G.L., Hudley, J.W., Holmes, C.W., Willard, D.A., and Marot, M., 2007.  Synthesis of age data and chronology for Florida Bay and Biscayne Bay cores collected for ecosystem history of south Florida’s estuaries projects.  U.S. Geological Survey Open-file report 2007-1203.


Cronin, T.M., Vogt, P.R., Willard, D.A., Thunell, R., Halka, J., Berke, M., and Pohlman, J., 2007.  Rapid sea level rise and ice sheet response to 8,200-year climate event.  Geophysical Research Letters 34, L20603, doi:10.1029/2007GL031318.


Willard, D.A, Bernhardt, C.E., Holmes, C.W., Landacre, B., and Marot, M., 2007.  Response of Everglades tree islands to environmental change.  Ecological Monographs, v. 76, no. 4, p. 565-583.


Bernhardt, C.E. and Willard, D.A., 2006.  Marl prairie vegetation response to 20th century hydrologic change.  U.S. Geological Survey Open-file report 2006-1355.


Wingard, G.L., Cronin, T.M., Holmes, C.W., Willard, D.A., Budet, C.A., and Ortiz, R.E., 2005.  Descriptions and preliminary report on sediment cores from the southwest coastal area, Everglades National Park, Florida.  U.S.  Geological Survey Open-file report 2005-1360.     


Willard, D.A., Phillips, T.L., Lesnikowska, A.D., and DiMichele, W.A., 2006.  Paleoecology of the Late Pennsylvanian-age Calhoun coal bed and implications for long-term dynamics of wetland ecosystems.  International Journal of Coal Geology, 69, p. 21-54.


Willard, D.A., Bernhardt, C.E., Korejwo, D.A., and Meyers, S.R., 2005. Eastern North American terrestrial ecosystem response to millennial-scale Holocene climate variability:  pollen-based climatic reconstruction.  Global and Planetary Change 47, p. 17-35.


Willard, D.A., Bernhardt, C.E., Weimer, L., Cooper, S.R., Gamez, D., and Jensen, J., 2004.  Atlas of pollen and spores of the Florida Everglades.  Palynology 28, p. 175-227.     


Bernhardt, C.E., Willard, D.A., Marot, M., and Holmes, C., 2004. Anthropologic and Natural Variation in the Ridge and Slough Pollen Assemblages. U.S. Geological Survey Open-File Report 2004-1448.


Willard, D.A. and Bernhardt, C.E., 2004.  Pollen stratigraphy and land-use change, Pocomoke Sound. In Cronin, TM., ed., Pocomoke Sound Sedimentary and Ecosystem History.  U.S. Geological Survey Open-File Report OFR-2004-1350, Chapter 7.     


Cronin, T.M., Robertson, M., Willard, D.A., and Halka, J., 2004.  Stratigraphy and age of Pocomoke Sound sediments. In Cronin, TM., ed., Pocomoke Sound Sedimentary and Ecosystem History.  U.S. Geological Survey Open-File Report OFR-2004-1350, Chapter 4.


Willard, D.A., Cronin, T.M., Bernhardt, C.E., and Damon, J., 2004.  Sediment transport in Pocomoke Sound, Maryland inferred from microfossils in surface sediments. In Cronin, TM., ed., Pocomoke Sound Sedimentary and Ecosystem History.  U.S. Geological Survey Open-File Report OFR-2004-1350, Chapter 3.


Cronin, T.M., Willard, D.A., Newell, W., Holmes, C.W., Halka, J., and Robertson, M., 2004.  Introduction to Pocomoke Sound sediments and hydrography.  In Cronin, TM., ed., Pocomoke Sound Sedimentary and Ecosystem History.  U.S. Geological Survey Open-File Report OFR-2004-1350, Chapter 1.     


Wingard, G.L., Cronin, T.M., Holmes, C.W., Willard, D.A., Dwyer, G., Ishman, S.E., Orem, W., Williams, C.P., Albietz, J., Bernhardt, C.E., Budet, C.A., Landacre, B., Lerch, T., Marot, M., and Ortiz, R.E., 2004.  Ecosystem history of southern and central Biscayne Bay:  summary report on sediment core analyses – year two.  U.S. Geological Survey Open-File Report 2004-1312.


Marshall, C.H., Pielke, R.A., Sr., Steyaert, L.T., and Willard, D.A., 2004.  The impact of anthropogenic land-cover change on the Florida peninsula sea breezes and warm season sensible weather.  Monthly Weather Review 132, p. 28-52.


Willard, D.A., 2004.  Tree islands of the Florida Everglades – Long-term stability and response to hydrologic change.  U.S. Geological Survey Fact Sheet 2004-3095, p. 1-4.


Wingard, G. L., Cronin, T.M., Dwyer, G.S., Ishman, S.E., Willard, D.A., Holmes, C.W., Bernhardt, C.E., Williams, C.P., Murray, J.B., Stamm, R.G., Murray, J.H., and Budet. C., 2003. Ecosytem history of southern and Central Biscayne bay: Summary report on sediment core analyses .  U.S. Geological Survey Open File Report 03-375.


Cronin, T.M., Dwyer, G.S., Kamiya, T., Schwede, S., Willard, D.A., 2003.  Medieval Warm Period, Little Ice Age and 20th century temperature variability from Chesapeake Bay.  Global and Planetary Change 36, p. 17-29.


Willard, D.A., 2003.  Tree islands of the Everglades – a disappearing resource.  U.S. Geological Survey Open File Report 03-26, p. 1-2.


Willard, D.A., Cronin, T.M., and Verardo, S., 2003.  Late Holocene climate and ecosystem variability from Chesapeake Bay sediment cores. The Holocene 13, p. 201-214.


Colman, S.M., Baucom, P.C., Bratton, J., Cronin, T.M., McGeehin, J.P., Willard, D.,A., Zimmerman, A., and Vogt, P.R.,  2002.  Radiocarbon dating of Holocene sediments in Chesapeake Bay.  Quaternary Research 57, p. 58-70.


Edwards, L.E., and Willard, D.A., 2001. Dinoflagellate cysts and pollen from sediment samples, Mississippi Sound and Gulf of Mexico.  in  Gohn, G.S., ed., Stratigraphic framework of the Neogene and Quaternary sediments of the Mississippi coastal zone, Jackson County, Mississippi, U.S. Geological Survey Open-file Report U.S. Geological Survey Open-file Report 01-415 (CD-ROM).


Willard, D.A., and Edwards, L.E., 2001.  Palynomorph biostratigraphy and paleoecology of subsurface upper Neogene and Quaternary sediments in southern Jackson County, Mississippi.  In Gohn, G.S., ed., Stratigraphic framework of the Neogene and Quaternary sediments of the Mississippi coastal zone, Jackson County, Mississippi. .  U.S. Geological Survey Open-file Report 01-415 (CD-ROM).


Willard, D.A., Holmes, C.W., and Weimer, L.M., 2001, The Florida Everglades Ecosystem:  Climatic and Anthropogenic Impacts over the Last Two Millennia.  Invited Chapter in Wardlaw, B.R. (ed), Paleoecology of South Florida.  Bulletins of American Paleontology, v. 361:  41-55.


Willard, D.A., Holmes, C.W., Korvela, M.S., Mason, D., Murray, J.B., Orem, W.H., and Towles, T.,  2001.  Paleoecological insights on fixed tree island development in the Florida Everglades:  I.  Environmental Controls.  Invited chapter in Sklar, F., and van der Valk, A., South Florida Tree Islands:  Kluwer Publishers:  The Netherlands, p. 117-151.


Willard, D.A., Weimer, L.M., and Riegel, W.L., 2001.  Pollen assemblages as paleoenvironmental proxies in the Florida Everglades.  Review of Palaeobotany and Palynology, v. 113, p. 213-235. 


Willard, D.A., and Korejwo, D.A., 2000.  Holocene palynology from Marion-Dufresne cores MD99-2209 and MD99-2207 from Chesapeake Bay:  Impacts of climate and historic land-use change.  In Cronin, T.M., Ed., Initial Report on IMAGES V Cruise of the Marion-Dufresne to Chesapeake Bay, June 20-22, 1999.  U.S. Geological Survey Open-file Report 00-306, p. 78-86.


Willard, D.A., Cronin, T.M., and Ishman, S.E., 2000.  Long-term patterns of vegetational and salinity change in the Lake Pontchartrain region, Louisiana.  U.S. Geological Survey Open-file Report 00-520, 35 pp.


Cronin, T.M., Willard, D.A., and Phillips, S.W., 2000.  Effects of climate variability and human activities on Chesapeake Bay and the implications for ecosystem restoration.  U.S. Geological Survey Fact Sheet, FS-116-00, 6 pp.  


Karlsen, A.W., T. M. Cronin, S. E. Ishman, D. A. Willard, C. W. Holmes, M. Marot, R. Kerhin.  2000.  Historical trends in Chesapeake Bay dissolved oxygen based on benthic foraminifera from sediment cores. Estuaries v. 23, p. 488-508. 


Cronin, T. M., Willard, D. A., R. T. Kerhin, A. W. Karlsen, C. Holmes, S. Ishman, S. Verardo, J. McGeehin, S. Colman, A. Zimmerman. 2000. Climatic variability in the eastern United States over the past millennium from Chesapeake Bay sediments. Geology v. 28, p. 3-6.


Willard, D.A., 1999.  Chesapeake Bay Pollen.  In Cronin, T.M., Wagner, R.S., and Slattery, M., eds., Microfossils from Chesapekae Bay sediments:  Illustrations and species database.  U.S. Geological Survey Open-file report 99-45, p. 135-159.


Cronin, T., Colman, S., D. Willard, R. Kerhin, C. Holmes, A. Karlsen, S. Ishman, J. Bratton. 1999. Interdisciplinary environmental project probes Chesapeake Bay down to the core.  EOS, AGU Transactions v. 80, p. 237, 240-241.


Grantz, A., Clark, D.L., Phillips, R.L., Srivastava, S.P., Blome, C.D., Gray, L.B., Haga, H., Mamet, B.L., McIntyre, D.J., McNeil, D.H., Mimckey, M.B., Mullen, M.W., Murchey, B.I., Ross, C.A., Stevens, C.H., Silberling, N.J., Wall, J.H., and Willard, D.A., 1998.  Phanerozoic stratigraphy of Northwind Ridge, magnetic anomalies in the Canada Basin, and the geometry and timing of rifting in the Amerasia basin, Arctic Ocean. GSA Bulletin 110, p. 801-820.


Ishman, S.E.  Cronin, T.M., Brewster-Wingard, G.L., Willard, D.A., and Verardo, D.J., 1998.  A record of ecosystem change, Manatee Bay, Barnes Sound, Florida: Journal of Coastal Research, v. 26, p. 125-138.


Willard, D.A., 1997.  Plio-Pleistocene pollen assemblages from the Yermak Plateau, Arctic Ocean:  ODP Sites 910 and 911:  Proceedings of the Ocean Drilling Program, Scientific Results, v. 151, p. 297-305.


Willard, D.A., 1997, Pollen census data from southern Florida:  sites along a nutrient gradient in Water Conservation Area 2A. U.S. Geological Survey Open-file Report, v. 97-497, p. 1-23.


Willard, D.A., Brewster-Wingard, G.L., Fellman, C., and Ishman, S.E., 1997, Paleontological Data from Mud Creek Core 1, southern Florida.  U.S. Geological Survey Open-file Report, v. 97-736, p. 1-18.


Willard, D.A., and Holmes, C.W., 1997, Pollen and geochronological data from South Florida:  Taylor Creek Site 2.  U.S. Geological Survey Open-file Report, v. 97-35, p. 1-29.


Willard, D.A., and L.M. Weimer, 1997. Palynological census data from surface samples in south Florida. U.S. Geological Survey Open-file Report, v. 97-867, p. 1-12.


Lesnikowska, A.D., and Willard, D.A., 1997.  Two new species of Scolecopteris (Marattiales), source fructifications of the stratigraphically significant miospores Torispora securis Balme and Thymospora thiessenii (Kosanke) Wilson & Venkatachala:  Review of Palaeobotany and Palynology, v. 95, p. 211-225.


Dowsett, H. J., and Willard, D.A., 1996.  Southeast Atlantic marine and terrestrial      response to middle Pliocene climate change:  Marine Micropaleontology 27:  181-93.


Willard, D.A., 1996.  Ecosystem history of terrestrial and freshwater ecosystems of southern Florida: U.S. Geological Survey Fact Sheet FS-146-96.


Gohn, G.S., Brewster-Wingard, G.L., Cronin, T.M., Edwards, L.E., Gibson, T.G., Rubin, M., and Willard, D.A.,  1996.  Neogene and Quaternary geology of a stratigraphic test hole on Horn Island, Mississippi Sound:  U.S. Geological Survey Open-file Report 96-20A and B.


Ishman, S.E., Brewster-Wingard, G.L., Willard, D.A., Cronin, T.M., Edwards, L.E., and Holmes, C.W., 1996.  Preliminary paleontologic report on Core T-24, Little Madeira Bay, Florida:  U.S. Geological Survey Open-file Report 96-543, 27 pp.


Willard, D.A., DiMichele, W.A., Hower, J.C., Eggert, D.L., and Rexroad, C.G., 1995, Paleoecology of the Springfield Coal Member (Middle Pennsylvanian, Illinois Basin) near the Leslie Cemetery paleochannel, southwestern Indiana:  International Journal of Coal Geology, v. 27, p. 59-98.


Willard, D.A., and Wingard, G.L., 1995.  South Florida Ecosystems:  Changes through time: U.S. Geological Survey Fact Sheet FS-171-95.


Wingard, G.L., Ishman, S.E., Cronin, T.M., Edwards, L.E., Willard, D.A., and Halley, R.B., 1995.  Preliminary analysis of down-core biotic assemblages:  Bob Allen Keys, Everglades National Park, Florida Bay:  U.S. Geological Survey Open-File Report 95-628, 35 pp.


Dowsett, H. J., Thompson, R. S., Barron, J. A., Cronin, T. M., Fleming, R.F., Ishman, S. E., Poore, R. Z., Willard, D. A., and Holtz, T. R., Jr., 1994, Paleoclimatic reconstruction of a warmer earth:  PRISM Middle Pliocene Northern Hemisphere synthesis:  Global and Planetary Change, v. 9, p. 169-195.


Willard, D. A., 1994, Palynological record from the North Atlantic region at 3 Ma:  vegetational distribution during a period of global warmth:  Review of Palaeobotany and Palynology, v. 83, p. 275-297.


Willard, D. A., Cronin, T. M., Ishman, S. E., and Litwin, R. J., 1993, Terrestrial and marine records of climate and environmental change during the Pliocene in subtropical Florida:  Geology, v. 21, p. 679-682.


Willard, D.A., 1993, Pliocene palynomorph census data from the Pinecrest Beds (Tamiami Formation) in Quality Aggregates Phase 6 pit, southwestern Florida:  U.S. Geological Survey Open-file Report, v. 93-563, 10 p.


Willard, D. A., 1993 , Vegetational patterns in the Springfield Coal (Middle Pennsylvanian, Illinois Basin):  Comparison of miospore and coal-ball records, in  Cecil, C. B., and Cobb, J., eds., Modern and Ancient Coal-Forming Environments:  Geological Society of America Special Paper , v. 286, p. 139-152.


Willard, D. A., and Phillips, T. L., 1993, Paleobotany and palynology of the Bristol Hill Coal Member (Bond Formation) and Friendsville Coal Member (Mattoon Formation) of the Illinois Basin (Upper Pennsylvanian):  Palaios, v. 8, p. 574-586.


Willard, D. A., 1992, Early Virgilian palynofloras from the Kinney Quarry, Manzanita Mountains, New Mexico:  New Mexico Bureau of Mines and Mineral Resources Bulletin,  v. 138, p. 49-60.


Bateman, R. M., DiMichele, W. A., and Willard, D. A.,  1992,  Experimental cladistic analyses of anatomically preserved tree-lycopsids from the Carboniferous of Euramerica:  Annals of the Missouri Botanical Garden, v. 79, p. 500-559.


Willard, D. A., 1992, Late Pliocene pollen assemblages from Ocean Drilling Project Hole 646B:  census data and paleoclimatic estimates:  U. S. Geological Survey Open-File Report, v. 92-405, 13 p.


Willard, D. A., and Klein, G. deV. , 1990, Tectonic subsidence history of the Central Appalachian basin and its influence on Pennsylvanian coal deposition:  Southeastern Geology, v. 30, p.  217-239.


Willard, D. A.,  1990,  Palynology of the Springfield Coal of the Illinois Basin (Middle Pennsylvanian) with Quantitative Comparison of Spore Floras and Coal-Ball Peats and Implications for Paleoecological Studies: University of Illinois, Urbana-Champaign,  Ph.D. dissertation,  216 pp.


Willard, D. A.,  1989,   Lycospora from Carboniferous Lepidostrobus compressions:  American Journal of Botany, v. 76, p. 1429-1440.


Willard, D. A. , 1989,  Source plants for Carboniferous microspores:  Lycospora from permineralized Lepidostrobus:  American Journal of Botany, v. 76, p.  820-827.


Klein, G. deV., and Willard, D. A., 1989, Reply to Comment on "Origin of the Pennsylvanian coal-bearing cyclothems of North America:  Geology, v. 17, p. 872.


Klein, G. deV.,  and Willard, D. A., 1989.  Origin of the Pennsylvanian coal-bearing  cyclothems of North America: Geology, v.  17, p.  152-155.


Weibel, C. P., R. L. Langenheim, Jr., and Willard, D. A.,  1989,  Cyclic strata of the Late Pennsylvanian outlier, east-central Illinois, Field Trip 17: in:  Vineyard, J. D. and Wedge, W. K.  (eds.), Geological Society of America 1989 Field Trip Guidebook, Missouri Department of Natural Resources Special Publication, v. 5, p.  141-169.


DiMichele, W. A., Phillips, T.L., and Willard, D. A. ,  1986,  Morphology and paleoecology of Pennsylvanian-age coal-swamp plants.  in: Broadhead, T.W. (ed.), Land Plants, notes for a short course:  Univ. Tenn. Studies in Geol. , v. 15, p.  97-114. 


My Science Topics

Science Topic
Geologic Processessedimentation
Ecology and Environmentecosystems
Ecology and Environmentestuarine ecosystems
Ecology and Environmentforests
Ecology and Environmentfreshwater ecosystems
Ecology and Environmenthabitat alteration
Ecology and Environmentwetlands

My USGS Science Strategy Areas

Climate Variability & Change

Contact Information

Debra Willard
12201 Sunrise Valley Dr
Reston, VA 20192
703-648-6953 - Fax
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