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David C Walters

David is a biological science tech with the Eastern Ecological Science Center at the Patuxent Research Refuge in Laurel, MD

David is a wetland ecologist, researching how coastal wetlands respond to sea level rise. With a background in biological and physical sciences, his work focuses on the interaction between wetland plant species and their physical environment. 

Professional Experience

  • 2020-Present - U.S. Geological Survey, Eastern Ecological Science Center, Biologist, Coastal Wetlands Group

  • 2017-2020 - NSA Contractor with U.S. Geological Survey, Patuxent Wildlife Research Refuge, Coastal Wetlands Group

  • 2013-2017 - Virginia Institute of Marine Science, Laboratory and Research Specialist

Education and Certifications

  • M.S., University of North Carolina- Chapel Hill, Geology (2013)

  • B.S., Longwood Univerity, Biology, concentration in Ecology (2011) 

Science and Products

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Canyon Mine Sampling

Minerals Science Team

The Minerals Integrated Science Team focuses on contaminant exposures in the environment that might originate from mineral resource activities including, transportation, storage, extraction and waste management. Perceived health risks to humans and other organisms will be distinguished from actual risks, if any. If actual risks are identified the science produced by this team can inform how to...
By
Ecosystems Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology
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Minerals Science Team

The Minerals Integrated Science Team focuses on contaminant exposures in the environment that might originate from mineral resource activities including, transportation, storage, extraction and waste management. Perceived health risks to humans and other organisms will be distinguished from actual risks, if any. If actual risks are identified the science produced by this team can inform how to...
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Environmental and Vegetation Data from Marsh-Forest Transgression Experiment at Blackwater National Wildlife Refuge, MD, USA

We conducted a field experiment at the Moneystump Swamp in the Blackwater National Wildlife Refuge in Dorchester, MD, USA to simulate a natural forest disturbance event (e.g., storm-induced flooding) by inducing the death of established trees (coastal loblolly pine, Pinus taeda) at the marsh-upland forest ecotone. There were three treatment components: Cut- where the trees were cut and removed, Gi
By
Eastern Ecological Science Center
Two scientists look down at a tablet that is connected to a monitoring box in the middle of a forest at Money Stump marsh
Sap Flow Monitoring at Blackwater National Wildlife Refuge
Sap Flow Monitoring at Blackwater National Wildlife Refuge
Two scientists look down at a tablet that is connected to a monitoring box in the middle of a forest at Money Stump marsh

Sap Flow Monitoring at Blackwater National Wildlife Refuge

Sap Flow Monitoring at Blackwater National Wildlife Refuge

Justine Neville (left) and Brendan Crossman (right) work to download and examine the data obtained from the site's sap flow probes, which were installed in early May. To learn more, contact Justine Neville at jneville@usgs.gov or David Walters at davidwalters@usgs.gov.

By
Eastern Ecological Science Center, Eastern Ecological Science Center
Two scientists look down at a tablet that is connected to a monitoring box in the middle of a forest at Money Stump marsh

Sap Flow Monitoring at Blackwater National Wildlife Refuge

Sap Flow Monitoring at Blackwater National Wildlife Refuge

Justine Neville (left) and Brendan Crossman (right) work to download and examine the data obtained from the site's sap flow probes, which were installed in early May. To learn more, contact Justine Neville at jneville@usgs.gov or David Walters at davidwalters@usgs.gov.

By
Eastern Ecological Science Center, Eastern Ecological Science Center
Two sensors drilled into a tree with wires hanging out the back
Sap flow sensors at Blackwater National Wildlife Preserve
Sap flow sensors at Blackwater National Wildlife Preserve
Two sensors drilled into a tree with wires hanging out the back

Sap flow sensors at Blackwater National Wildlife Preserve

Sap flow sensors at Blackwater National Wildlife Preserve

Close up of the newly installed sap flow sensors at Blackwater National Wildlife Preserve. These sensors were installed by EESC's Justine Neville and Ken Krauss of the USGS Wetland and Aquatic Research Center in Lafayette, LA. These sensors will be used to analyze how the trees in a marsh ecosystem respond to changing ecological and climatic conditions.

By
Eastern Ecological Science Center
Two sensors drilled into a tree with wires hanging out the back

Sap flow sensors at Blackwater National Wildlife Preserve

Sap flow sensors at Blackwater National Wildlife Preserve

Close up of the newly installed sap flow sensors at Blackwater National Wildlife Preserve. These sensors were installed by EESC's Justine Neville and Ken Krauss of the USGS Wetland and Aquatic Research Center in Lafayette, LA. These sensors will be used to analyze how the trees in a marsh ecosystem respond to changing ecological and climatic conditions.

By
Eastern Ecological Science Center
A scientist drills into a pine tree with a cordless drill in a forest with another scientist helping her to install sap flow
Sap probe install
Sap probe install
A scientist drills into a pine tree with a cordless drill in a forest with another scientist helping her to install sap flow

Sap probe install

Sap probe install

EESC USGS Mendenhall Fellow Justine Neville installing sap flow probes at Blackwater National Wildlife Refuge with USGS colleague Ken Krauss from USGS Wetland and Aquatic Research Center in Lafayette, LA. Sap flow probes will be used to monitor transpiration rates in coastal forests to assess the water usage of trees experiencing stress from inundation.

By
Eastern Ecological Science Center
A scientist drills into a pine tree with a cordless drill in a forest with another scientist helping her to install sap flow

Sap probe install

Sap probe install

EESC USGS Mendenhall Fellow Justine Neville installing sap flow probes at Blackwater National Wildlife Refuge with USGS colleague Ken Krauss from USGS Wetland and Aquatic Research Center in Lafayette, LA. Sap flow probes will be used to monitor transpiration rates in coastal forests to assess the water usage of trees experiencing stress from inundation.

By
Eastern Ecological Science Center
Brendan Crossman takes a measurement with a salinity probe in a wetland adjacent to a forest.
Measuring salinity as part of a vegetation survey
Measuring salinity as part of a vegetation survey
Brendan Crossman takes a measurement with a salinity probe in a wetland adjacent to a forest.

Measuring salinity as part of a vegetation survey

Measuring salinity as part of a vegetation survey

Brendan Crossman measures porewater salinity in a vegetation plot situated on a survey transect from the wetland into the adjacent upland forest.

By
Eastern Ecological Science Center, Eastern Ecological Science Center
Brendan Crossman takes a measurement with a salinity probe in a wetland adjacent to a forest.

Measuring salinity as part of a vegetation survey

Measuring salinity as part of a vegetation survey

Brendan Crossman measures porewater salinity in a vegetation plot situated on a survey transect from the wetland into the adjacent upland forest.

By
Eastern Ecological Science Center, Eastern Ecological Science Center

Climate-driven tradeoffs between landscape connectivity and the maintenance of the coastal carbon sink

Ecosystem connectivity tends to increase the resilience and function of ecosystems responding to stressors. Coastal ecosystems sequester disproportionately large amounts of carbon, but rapid exchange of water, nutrients, and sediment makes them vulnerable to sea level rise and coastal erosion. Individual components of the coastal landscape (i.e., marsh, forest, bay) have contrasting responses to s
Authors
Kendall Valentine, Ellen R. Herbert, David C Walters, Yaping Chen, Alexander J. Smith, Matthew L. Kirwan
By
Climate Research and Development Program, Eastern Ecological Science Center

GPS data from 2019 and 2020 campaigns in the Chesapeake Bay region towards quantifying vertical land motions

The Chesapeake Bay is a region along the eastern coast of the United States where sea-level rise is confounded with poorly resolved rates of land subsidence, thus new constraints on vertical land motions (VLM) in the region are warranted. In this paper, we provide a description of two campaign-style Global Positioning System (GPS) datasets, explain the methods used in data collection and validatio
Authors
Gabrielle Troia, Sarah Stamps, R. Russell Lotspeich, James M. Duda, Kurt J. McCoy, William Moore, Philippe Hensel, Ryan Hippenstiel, Thomas McKenna, David C. Andreasen, Charles Geoghegan, Thomas P Ulizo, Madeline Kronebusch, Joel A. Carr, David Walters, Neil Winn
By
Ecosystems Mission Area, Climate Research and Development Program, Chesapeake Bay Activities, Eastern Ecological Science Center, Fort Collins Science Center, Virginia and West Virginia Water Science Center

Experimental tree mortality does not induce marsh transgression in a Chesapeake Bay low-lying coastal forest

Transgression into adjacent uplands is an important global response of coastal wetlands to accelerated rates of sea level rise. “Ghost forests” mark a signature characteristic of marsh transgression on the landscape, as changes in tidal inundation and salinity cause bordering upland tree mortality, increase light availability, and the emergence of tidal marsh species due to reduced competition. To
Authors
David C Walters, Joel A. Carr, Alyssa Hockaday, Joshua A Jones, Eliza McFarland, Katya Kovalenko, Matthew L. Kirwan, Donald Cahoon, Glenn R. Guntenspergen
By
Ecosystems Mission Area, Climate Research and Development Program, Land Management Research Program, Chesapeake Bay Activities, Eastern Ecological Science Center

Sea level driven marsh expansion in a coupled model of marsh erosion and migration

Coastal wetlands are among the most valuable ecosystems on Earth, where ecosystem services such as flood protection depend nonlinearly on wetland size and are threatened by sea level rise and coastal development. Here we propose a simple model of marsh migration into adjacent uplands and couple it with existing models of seaward edge erosion and vertical soil accretion to explore how ecosystem con
Authors
Matthew L. Kirwan, David C. Walters, William G. Reay, Joel A. Carr
By
Ecosystems Mission Area, Eastern Ecological Science Center

Non-USGS Publications**

Lauzon, R., Murray, A. B., Moore, L. J., Walters, D. C., Kirwan, M. L., & Fagherazzi, S. (2018). Effects of marsh edge erosion in coupled barrier island-marsh systems and geometric constraints on marsh evolution. Journal of Geophysical Research: Earth Surface, 123, 1218– 1234. https://doi.org/10.1029/2017JF004530
Moore, L.J. et al. (2018). The Role of Ecomorphodynamic Feedbacks and Landscape Couplings in Influencing the Response of Barriers to Changing Climate. In: Moore, L., Murray, A. (eds) Barrier Dynamics and Response to Changing Climate. Springer, Cham. https://doi.org/10.1007/978-3-319-68086-6_10
Schieder, N.W., Walters, D.C. & Kirwan, M.L. Massive Upland to Wetland Conversion Compensated for Historical Marsh Loss in Chesapeake Bay, USA. Estuaries and Coasts 41, 940–951 (2018). https://doi.org/10.1007/s12237-017-0336-9
Walters, D.C. & M.L. Kirwan, Optimal hurricane overwash thickness for maximizing marsh resilience to sea level rise, Ecology and Evolution (2016). https://onlinelibrary.wiley.com/doi/10.1002/ece3.2024
Moore, L.J., Walters, D.C., et al., Ecomorphodynamic feedbacks and couplings between landscape units affect barrier island response to changing climate. In: Coastal Sediments, (2015). https://www.worldscientific.com/doi/10.1142/9789814689977_0246
Walters, D., et al., Interactions between barrier islands and backbarrier marshes affect island system response to sea level rise: Insights from a coupled model, Journal of Geophysical Research: Earth Surface, (2014). https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014JF003091

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

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