Piermont Marsh

<div style='text-align:Left;'><div><div><p><span>Tidal wetland plant communities of the Hudson River National Estuarine Research Reserve 2005 for Iona Island, Piermont Marsh, Stockport Flats and Tivoli Bays. This vegetation community mapping dataset was compiled by the Institute for Resource Information Sciences from the interpretation of high resolution 2005 aerial photography. The classification scheme contains 20 vegetation community type classes and was developed by Hudson River National Estuarine Research Reserves (Hudson River NERR). This dataset was generated as an update to previous inventories (1991 &amp; 1997) which utilized the same classification scheme. These datasets enable the Reserve Manager and Research Coordinator to assess trends in vegetation change, evaluate current management techniques, and direct future actions.</span></p><p><span>The 2005 mapping of the Hudson River NERR sites is the third effort focused on documenting existing vegetation within the Reserve sites. These mapping efforts were designed to provide a management tool for each of the Reserve sites and therefore, are at a higher spatial and taxonomic resolution than other wetland inventories. In 1991, a mapping effort was undertaken by Coastal Services which resulted in analog maps comprised of 100 vegetation classes. Mapping of the vegetation community types at each of the four Hudson River NERR sites was undertaken again in 1997. The 1997 classification scheme of 20 classes was derived from the initial 1991 classification, modified as directed by the Hudson River NERR Research Coordinator. During the development of the 1997 dataset, the 1991 dataset was reclassified to the new 20 class scheme. This same classification scheme was used for all subsequent mapping at all Hudson River NERR sites. This project utilized the visual vocabulary of vegetation cover types and the methodology for boundary determination developed for the 1997 mapping effort (IRIS, 1997). The vocabulary is described in terms of key indicators. They are color, texture, pattern, shadow, size, shape, and landscape location. In the interpretation process, the analyst made a correlation between aerial photographic signatures and ground conditions through viewing photographs, visiting the marshes and consulting on a frequent basis with expert project collaborators. The classification of objects into vegetation community types is based upon their dominant visual characteristics. A vegetation community type polygon was defined by drawing a line at the boundary between different communities. When there was a distinct change in color, texture or other key indicator, the edge was delineated by tracing. When there was a gradual change the delineation was made where the two vegetation community constituents appeared in equal quantity.</span></p></div></div></div>