The Ocean Blog
Make Me Care About: Phragmites
This Chesapeake Bay shoreline may look picturesque, but the plant that dominates it is an invasive strain of Phragmites australis. The plant has invaded wetlands along the East Coast.
This week at the Smithsonian Ocean Portal we embark on an experiment we're calling "Make Me Care." The concept is simple: we ask a renowned expert to tell us why we should care about his or her marine subject matter. We're giving them only about a minute on video to accomplish the task, so it's a difficult - and not very fair - challenge.
Dennis Whigham is a senior botanist at the Smithsonian Environmental Research Center, in Edgewater, Md. He's graciously agreed to be the first expert to participate.
Whigham is a specialist in many subject areas, including mangroves, orchids, tidal freshwater wetlands, and Phragmites australis, a plant that has successfully invaded wetland ecosystems around the world.
We caught up with him on March 30 while he was talking with visitors in the National Museum of Natural History's Sant Ocean Hall.
So Dr. Dennis Whigham, (please) make us care about: Phragmites (pronounced frag-MITE-ees).
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In New England, Phragmites is associated with salt marsh decline. It is salt tolerant, but only to a certain degree. Your salt marsh is not getting enough salt water at high tide when Phragmites appears. Enlarged culverts and replacing old bridges in some cases is all that is required to restore a salt marsh.
Expansive stands of Phragmites are symptomatic of larger scale watershed issues that are almost always associated with watershed development.
Tidal wetlands develop over periods of 4,000 years or more. During this time they are subject to many environmental and climactic changes. The only way to effectively control Phragmites over these projected timeframes is by increasing support and enforcement of our existing environmental policies and better refining storm water management policies.
Improving watershed permeability will restore soil sulfides in tidal wetlands. Indigenous tidal wetland flora evolved with a higher soil sulfide tolerance than Phragmites. Increased soil sulfides will decrease Phragmites’ competitive advantage over indigenous flora. The restored soil sulfides coupled with current sea level rise will establish a long-term trajectory for indigenous flora to out compete Phragmites.
Geoffrey M. Wilson