As part of a $5 million grant from the National Oceanic and Atmospheric Administration (NOAA), SERC will lead a team from 7 institutions to investigate the combined effects of 'multiple stressors' on nearshore habitats throughout the Chesapeake region. Invasive species, nutrient runoff and shoreline hardening are just a few of the factors contributing to the overall decline of these critical areas.

Our Lab will focus on the non-native genotype of Common Reed (Phragmites australis) that has become a major invader of brackish wetlands in the Chesapeake Bay region and elsewhere throughout North America.

Our interest in Phragmites began with an EPA-funded project to investigate linkages between the land and estuary within the Chesapeake Bay. Former lab member, Ryan King (Baylor University) and his collaborators, including Denice Waldrop (Pennsylvania State University) clearly demonstrated a strong relationship between land development and the abundance and nutrient content of Phragmites.

In 2006-2008, SI post-doctoral fellow Karin Kettenring (Utah State University) and Smithsonian interns Heather Baron (Oregon State University) and Sally Gallagher (University of Wisconsin) joined the Lab to investigate patterns of invasion as well as the underlying factors that were responsible for the rapid expansion of Phragmites australis. This research demonstrated that the invasion is linked to the level of genetic diversity within the Phragmites patches, i.e. the greater the genetic diversity, the higher the production of viable seeds.

There are still many questions to be answered related to the invasion of Phragmites australis such as: what are the specific factors that allow seedlings to become established in undisturbed wetlands and does the presence of patches of Phragmites australis have negative consequences in aquatic ecosystems.

The NOAA-funded project provides the Lab the opportunity to continue our collaboration with Karin, Denice and others as we investigate these questions to determine the underlying factors that have resulted in the rapid expansion of the European genotype of Phragmites australis.

Learn more about our Phragmites research:

Kettenring, K.M., M.K. McCormick, H.M. Baron, D.F. Whigham. 2010. Phragmites australis (Common Reed) invasion in the Rhode River subestuary of the Chesapeake Bay: Disentangling the effects of foliar nutrients, genetic diversity, patch size and seed viability. Estuaries and Coasts 33:118-126. pdf request

McCormick, M.K., K.M. Kettenring, H.M. Baron, D.F. Whigham. 2010. Extent and mechanisms of Phragmites australis spread in brackish wetlands in a subestuary of the Chesapeake Bay. Wetlands 30:67-74. pdf request

Kettenring, K.M. and D.F. Whigham. 2009. Seed viability and seed dormancy of non-native Phragmites australis in developed and forested watersheds of the Chesapeake Bay, USA. Aquatic Botany 91:199-204. pdf request

King, R.S., W.V. DeLuca, D.F. Whigham and P.P. Marra. 2007. Threshold effects of coastal urbanization on Phragmites australis (common reed) abundance and foliar nitrogen in Chesapeake Bay. Estuaries and Coasts 30:469-481. pdf request

King, R.S., M.E. Baker, D.F. Whigham, D.E. Weller, T.E.Jordan, P.F. Kazyak, and M.K. Hurd. 2005. Spatial considerations for linking watershed land cover to ecological indicators in streams. Ecological Applications 15:137-153. pdf request