Donald Cahoon, Ph.D.
Donald R. Cahoon, PhD, is a senior research ecologist with the U. S. Geological Survey at the Patuxent Wildlife Research Center in Laurel, Maryland and an internationally recognized expert in tidal wetland elevation dynamics and wetland vulnerability to climate change effects (e.g., sea-level rise and storms). He is a Fellow and Past President of the Society of Wetland Scientists. Trained as a botanist and plant ecologist, he has spent the past 30 years working as a physical geographer. In 1992 he developed a field method for measuring tidal wetland accretion and elevation dynamics (the surface elevation table – marker horizon (SET-MH) method) that is used by scientists in coastal wetlands throughout the United States and in 32 countries for evaluating the critical driving forces and subsurface processes controlling elevation, and the impact of current management and restoration practices on elevation dynamics and wetland stability. His research focuses on the processes and external drivers that control wetland elevation dynamics and wetland sustainability across the broad spectrum of coastal environmental settings.
- BA, Drew University, 1972, Botany
- MS, University of Maryland, 1975, Plant Ecology
- PhD, University of Maryland, 1982, Plant Ecology
- Merit Award, Society of Wetland Scientists, 2011
- Fellow, Society of Wetland Scientists, 2011
- President, Society of Wetland Scientists, 1997-1998
- USGS, Global Change Research Program funding, 1991-present
- Star Award: 1998, 2001, 2006, 2009
Science and Products
The Challenge: The high winds and storm surge associated with Hurricane Sandy impacted coastal wetlands from Virginia to Maine. Understanding the ecological and geological impacts of hurricanes on coastal wetlands and their interactive effects with local conditions is important for identifying resilience of these communities to predicted global sea-level rise. Given the projected increase in number and intensity of hurricanes, we need to understand the impact of physical and chemical stressors associated with hurricanes in order to efficiently and effectively protect and restore these critical habitats. Storm-related sediment deposition and erosion are two of the potential long-term impacts of severe storms such as Hurricane Sandy on marsh surface elevation and resilience. But wetland impacts are unique for every major storm because of each storm’s unique characteristics (wind speed, angle of approach, tidal stage).
Assessing coastal wetland vulnerability to sea-level rise along the northern Gulf of Mexico coast: Gaps and opportunities for developing a coordinated regional sampling network
Coastal wetland responses to sea-level rise are greatly influenced by biogeomorphic processes that affect wetland surface elevation. Small changes in elevation relative to sea level can lead to comparatively large changes in ecosystem structure, function, and stability. The surface elevation table-marker horizon (SET-MH) approach is being used...Osland, Michael J.; Griffith, Kereen T.; Larriviere, Jack C.; Feher, Laura C.; Cahoon, Donald R.; Enwright, Nicholas M.; Oster, David A.; Tirpak, John M.; Woodrey, Mark S.; Collini, Renee C.; Baustian, Joseph J.; Breithaupt, Joshua L.; Cherry, Julia A; Conrad, Jeremy R.; Cormier, Nicole; Coronado-Molina, Carlos A.; Donoghue, Joseph F.; Graham, Sean A.; Harper, Jennifer W.; Hester, Mark W.; Howard, Rebecca J.; Krauss, Ken W.; Kroes, Daniel; Lane, Robert R.; Mckee, Karen L.; Mendelssohn, Irving A.; Middleton, Beth A.; Moon, Jena A.; Piazza, Sarai; Rankin, Nicole M.; Sklar, Fred H.; Steyer, Gregory D.; Swanson, Kathleen M.; Swarzenski, Christopher M.; Vervaeke, William; Willis, Jonathan M; Van Wilson, K.
Processes contributing to resilience of coastal wetlands to sea-level rise
The objectives of this study were to identify processes that contribute to resilience of coastal wetlands subject to rising sea levels and to determine whether the relative contribution of these processes varies across different wetland community types. We assessed the resilience of wetlands to sea-level rise along a transitional gradient from...Stagg, Camille L.; Krauss, Ken W.; Cahoon, Donald R.; Cormier, Nicole; Conner, William H.; Swarzenski, Christopher M.
Elevation dynamics in a restored versus a submerging salt marsh in Long Island Sound
Accelerated sea-level rise (SLR) poses the threat of salt marsh submergence, especially in marshes that are relatively low-lying. At the same time, restoration efforts are producing new low-lying marshes, many of which are thriving and avoiding submergence. To understand the causes of these different fates, we studied two Long Island Sound marshes...Anisfeld, Shimon C.; Hill, Troy D.; Cahoon, Donald R.
The surface elevation table and marker horizon technique: A protocol for monitoring wetland elevation dynamics
The National Park Service, in response to the growing evidence and awareness of the effects of climate change on federal lands, determined that monitoring wetland elevation change is a top priority in North Atlantic Coastal parks (Stevens et al, 2010). As a result, the NPS Northeast Coastal and Barrier Network (NCBN) in collaboration with...James C. Lynch; Phillippe Hensel; Cahoon, Donald R.
Sediment transport-based metrics of wetland stability
Despite the importance of sediment availability on wetland stability, vulnerability assessments seldom consider spatiotemporal variability of sediment transport. Models predict that the maximum rate of sea level rise a marsh can survive is proportional to suspended sediment concentration (SSC) and accretion. In contrast, we find that SSC and...Ganju, Neil K.; Kirwan, Matthew L.; Dickhudt, Patrick J.; Guntenspergen, Glenn R.; Cahoon, Donald R.; Kroeger, Kevin D.
Sea level and turbidity controls on mangrove soil surface elevation change
Increases in sea level are a threat to seaward fringing mangrove forests if levels of inundation exceed the physiological tolerance of the trees; however, tidal wetlands can keep pace with sea level rise if soil surface elevations can increase at the same pace as sea level rise. Sediment accretion on the soil surface and belowground production of...Lovelock, Catherine E.; Fernanda Adame, Maria; Bennion, Vicki; Hayes, Matthew; Reef, Ruth; Santini, Nadia; Cahoon, Donald R.
Estimating relative sea-level rise and submergence potential at a coastal wetland
A tide gauge records a combined signal of the vertical change (positive or negative) in the level of both the sea and the land to which the gauge is affixed; or relative sea-level change, which is typically referred to as relative sea-level rise (RSLR). Complicating this situation, coastal wetlands exhibit dynamic surface elevation change (both...Cahoon, Donald R.
Below the disappearing marshes of an urban estuary: historic nitrogen trends and soil structure
Marshes in the urban Jamaica Bay Estuary, New York, USA are disappearing at an average rate of 13 ha/yr, and multiple stressors (e.g., wastewater inputs, dredging activities, groundwater removal, and global warming) may be contributing to marsh losses. Among these stressors, wastewater nutrients are suspected to be an important contributing cause...Wigand, Cathleen; Roman, Charles T.; Davey, Earl; Stolt, Mark; Johnson, Roxanne; Hanson, Alana; Watson, Elizabeth B.; Moran, S. Bradley; Cahoon, Donald R.; Lynch, James C.; Rafferty, Patricia
How mangrove forests adjust to rising sea level
Mangroves are among the most well described and widely studied wetland communities in the world. The greatest threats to mangrove persistence are deforestation and other anthropogenic disturbances that can compromise habitat stability and resilience to sea-level rise. To persist, mangrove ecosystems must adjust to rising sea level by building...Krauss, Ken W.; McKee, Karen L.; Lovelock, Catherine E.; Cahoon, Donald R.; Saintilan, Neil; Reef, Ruth; Chen, Luzhen
The surface elevation table: marker horizon method for measuring wetland accretion and elevation dynamics
Tidal wetlands are highly sensitive to processes that affect their elevation relative to sea level. The surface elevation table–marker horizon (SET–MH) method has been used to successfully measure these processes, including sediment accretion, changes in relative elevation, and shallow soil processes (subsidence and expansion due to root...Callaway, John C.; Cahoon, Donald R.; Lynch, James C.
A global standard for monitoring coastal wetland vulnerability to accelerated sea-level rise
Sea-level rise threatens coastal salt-marshes and mangrove forests around the world, and a key determinant of coastal wetland vulnerability is whether its surface elevation can keep pace with rising sea level. Globally, a large data gap exists because wetland surface and shallow subsurface processes remain unaccounted for by traditional...Webb, Edward L.; Friess, Daniel A.; Krauss, Ken W.; Cahoon, Donald R.; Guntenspergen, Glenn R.; Phelps, Jacob
Updating Maryland's sea-level rise projections
With its 3,100 miles of tidal shoreline and low-lying rural and urban lands, “The Free State” is one of the most vulnerable to sea-level rise. Historically, Marylanders have long had to contend with rising water levels along its Chesapeake Bay and Atlantic Ocean and coastal bay shores. Shorelines eroded and low-relief lands and islands, some...Boesch, Donald F.; Atkinson, Larry P.; Boicourt, William C.; Boon, John D.; Cahoon, Donald R.; Dalrymple, Robert A.; Ezer, Tal; Horton, Benjamin P.; Johnson, Zoe P.; Kopp, Robert E.; Li, Ming; Moss, Richard H.; Parris, Adam; Sommerfield, Christopher K.