Keryn Gedan

Keryn Gedan

Assistant Professor of Biology
SEH 5685
Phone: 202-994-0274

Marine community ecology, tidal wetland ecology, and conservation biology

Current Research

My lab investigates the response of coastal and marine species and ecosystems to global changes in climate, sea level, nutrient availability, and invasive species. We focus on conservation-priority, shallow, marine ecosystems, especially tidal marsh. At the interface of land and sea, tidal marshes are a high value and accessible ecosystem subject to both terrestrial and marine influences and affected by rapid coastal land use change. We examine the role of foundation species, plant-soil feedbacks, and strong environmental gradients in the ecological response of tidal marshes to global and local human impacts. We primarily rely upon an experimental ecological approach in the greenhouse and field. Current field sites are the Chesapeake Bay Eastern Shore and Mid-Atlantic coastal bays.

If you are interested in joining the lab as a graduate student or postdoc, I would love to speak with you. Please send me an email with your CV.   

Current research projects

  • Ecology of marsh migration at the tidal marsh-forest ecotone
  • The effect of sea level rise on coupled backbarrier-barrier island systems
  • Marsh migration into agricultural landscapes on the Chesapeake Eastern Shore
  • Environmental stress and the formation of novel mutualisms


B.A., Biology and Environmental Studies, Tufts University, 2002

Ph.D., Ecology and Evolutionary Biology, Brown University, 2010

Postdoctoral work, David H. Smith Fellow, Smithsonian Environmental Research Center


Finney, T.E., Gedan, K.B., and C.B. Fenster. 2016Allocation patterns contribute to the distributional limits of a flood tolerant ecotype of Chamaecrista fasciculataAquatic Botany 34: 31-38.

Aslan, C.E., Bronstein, J.R., Rogers, H.S., Gedan, K.B., Brodie, J., Palmer, T.M., and T.P. Young. 2016. Leveraging nature’s backup plans to incorporate interspecific interactions and resilience into restoration. Restoration Ecology. doi: 10.1111/rec.12346

Aslan, C.E., Sikes, B.A., and K.B. Gedan. 2015Research on mutualisms between native and non-native partners can contribute to critical ecological insights. Neobiota 26:39-54.

Altieri, A.H. and K.B. Gedan. 2015. Climate change and the expansion of dead zones. Global Change Biology 21:1395-1406.

Gedan, K.B., Rick, T.C., Grossinger, R.M., and D.L. Breitburg. 2015. Historical Information for Ecological Restoration in Estuaries and Coastal Ecosystems. In Marine Historical Ecology in Conservation: Applying the Past to Manage for the Future. Eds. Kittinger, J., McClenachan, L., Gedan, K.B., and L.K. Blight. UC Press.

Gedan, K.B., Breitburg, D.L., and L. Kellogg. 2014. Accounting for multiple foundation species in restoration benefits. Restoration Ecology 22:517–524.

Silliman, B., Mozdzer, T., Angelini, C., Brundage, J., Bakker, J., Esselink, P., Gedan, K., von de Koppel, J., and A. Baldwin. 2014. Livestock as a potential biological control agent for an invasive wetland plant. PeerJ  2:e567.

Gedan, K.B., Altieri, A.H., and M.D. Bertness. 2011. Uncertain future of New England salt marshes. Marine Ecology Progress Series 434:229-237.

Gedan, K.B., Bernhardt, J., Bertness, M.D., and H.M. Leslie. 2011. Substrate size mediates thermal stress in the rocky intertidal. Ecology 92:576–582.

Gedan, K.B., Kirwan, M. L., Wolanski, E., Barbier, E.B., and B. R. Silliman. 2011. The present and future role of coastal wetland vegetation in protecting shorelines: Answering recent challenges to the paradigm. Climatic Change 106:7-29.

Gedan, K.B. and Bertness, M.D. 2010How will warming affect the salt marsh foundation species Spartina patens and its ecological role? Oecologia 164:479-487.

Brandt, L., Bromberg Gedan, K. and E. Garcia. 2010. Disturbance type determines occupancy of a New England high marsh by sand fiddler crabs (Uca pugilator) and ants (Tetramorium caespitum and Formica subsericea). Northeastern Naturalist 17:103-114.

Holdredge, C., Bertness, M.D., Herrmann, N.C. and K.B. Gedan. 2010. Fiddler crab control of cordgrass primary production in sandy sediments. Marine Ecology Progress Series 399: 253-259.

Gedan, K.B. and M.D. Bertness. 2009. Experimental warming causes rapid loss of plant diversity in New England salt marshes. Ecology Letters 12: 842-848.

Gedan, K.B. and B.R. Silliman. 2009. Using facilitation theory to enhance mangrove restoration. Ambio 38: 109.

Gedan, K.B. and B.R. Silliman. 2009. Patterns of salt marsh loss within coastal regions of North America: pre-settlement to today. In Human Impacts on Salt Marshes: A Global Perspective. Eds. Silliman, B.R., Grosholz, E.D., and M.D. Bertness. UC Press.

Crain, C.M., Gedan, K.B., and M. Dionne. 2009. Hydrologic alteration of New England tidal marshes by mosquito ditching and tidal restriction. In Human Impacts on Salt Marshes: A Global Perspective. Eds. Silliman, B.R., Grosholz, E.D., and M.D. Bertness. UC Press.

Gedan, K.B., Crain, C.M. and M.D. Bertness. 2009Small mammal herbivore control of secondary succession in New England tidal marshes. Ecology 90: 430-440.

Gedan, K.B., Silliman, B.R. and M.D. Bertness. 2009. Centuries of human-driven change in salt marsh ecosystems. Annual Reviews of Marine Science 1: 117-141.

Bromberg, K.D. and M.D. Bertness.  2005. Reconstructing New England salt marsh losses using historical maps. Estuaries 28: 823-832.                                           

Coley, P.D., Lokvam, J. Rudolph, K., Bromberg, K., Sackett, T.E., Wright, L., Brenes-Arguedas, T., Dvorett, D., Ring, S., Clark, A., Baptiste, C., Pennington, R.T., and T.A. Kursar. 2005. Divergent defensive strategies of young leaves in two species of IngaEcology 86: 2633-2643.

Bruno, J.F., Fridley, J.D., Bromberg, K.D., and M.D. Bertness. 2005. Insights into biotic interactions from studies of species invasions.  in Species Invasions: Insights into Ecology, Evolution, and Biogeography. Eds. Sax, D.F., Stachowicz, J.J., and S.D. Gaines.  Sinauer.