Environmental Science and Management
Charles, Roman, T
Swift, Judith, M
Phragmites australis, Restoration, Herring River, Salt Marsh, Cape Cod, GIS
My presentation invites you to learn about what is involved in planning a salt marsh restoration project. The Herring River Estuary is a disturbed salt marsh ecosystem at Cape Cod National Seashore which has been diked since 1909. The National Park Service (NPS), in cooperation with many partners, is engaged in efforts to restore the now impacted 1,100 acre estuary by re-introducing tidal flow. There is significant complexity involved in trying to restore such an intricate system- from the multitude of environmental factors to important social and economic consequences. There are also several benefits to restored tidal flow. My thesis project allowed me to assist the National Park Service by mapping the predicted response of Phragmites australis to restoration. P. australis is a key invasive plant species of management interest.
Many of the salt marshes in the United States have been significantly altered and disturbed over time. As we have begun to realize the important benefits these ecosystems provide and the negative effects that diking has had on these systems, efforts have begun to restore salt marshes all along the coast. However ecosystems are extremely complex and restoration efforts cannot be done successfully without proper planning. Many of these disturbed systems have been in their existing state for over 100 years and any restoration will cause significant changes to the area. There are many potential consequences that citizens near these salt marshes are legitimately concerned about and the high cost of a restoration can also be prohibitive. However if proper precautions are taken there are significant environmental benefits to such restorations.
My role has been to work with the adaptive management team of scientists who are helping to predict the changes that can be expected as the restoration proceeds. Incremental openings to the new dike will allow the estuary to slowly respond to increased tidal flow. By slowly opening the new dike, over the course of several years, the NPS will also be able to monitor system responses and make sure the restoration is proceeding successfully and make adaptive changes if anything is wrong. My specific focus has been on predicting the changes in spread and location of key species as the restoration proceeds. I have focused mostly on Phragmites australis, a tall invasive reed grass that has negative effects on salt marsh ecosystems. As an invasive plant, P. australis is of particular management concern and predicting its response to the restoration is beneficial to helping limit its spread. Using literature on its life history, current data on its occurrence in the estuary, and modeled predictions of restored salinity and tidal levels, I have produced several maps and an associated report on the predicted response of P. australis to the planned restoration. Data analysis and mapping was done using a Geographic Information System (GIS), called ArcGIS 10. The report includes a map of what areas are most likely to see vigorous P. australis growth and a map of areas prone to P. australis seed germination. My analysis has allowed me to consider possible management techniques for P. australis which are also included in my report. Overall, I hope you will find my project to be interesting and informative as it addresses both the complexity of planning a salt marsh restoration and the value of restoring tidal flow.