Hudson River NERR Vegetation Maps

<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>

本数据集为哈德逊河国家河口研究保护区（Hudson River National Estuarine Research Reserve, Hudson River NERR）2005年针对艾奥纳岛、皮埃蒙特沼泽、斯托克波特滩涂与蒂沃利湾的潮滩植物群落数据集。该植被群落制图数据集由资源信息科学研究所（Institute for Resource Information Sciences）基于2005年高分辨率航空摄影影像解译编制而成。其分类体系包含20种植物群落类型，由哈德逊河国家河口研究保护区（Hudson River NERR）制定。本数据集是对此前两次植被清查（1991年与1997年，二者均采用同一分类体系）的更新成果。此类数据集可帮助保护区管理者与研究协调员评估植被变化趋势、评估现有管理手段并指导未来行动。

2005年哈德逊河国家河口研究保护区（Hudson River NERR）站点植被制图是该保护区第三次针对站点内现存植被开展的建档工作。本次制图工作旨在为各保护区站点提供管理工具，因此其空间分辨率与分类学分辨率均高于其他湿地清查项目。1991年，海岸服务署（Coastal Services）开展了首次制图工作，生成了包含100种植被类别的模拟地图。1997年，哈德逊河国家河口研究保护区四个站点的植被群落类型制图工作再次启动。1997年的20类分类体系源自1991年的初始分类体系，并根据哈德逊河国家河口研究保护区研究协调员的指示进行了调整优化。在1997年数据集编制期间，1991年的数据集被重新归类至新的20类分类体系中。此后哈德逊河国家河口研究保护区所有站点的后续制图工作均沿用了该分类体系。本项目沿用了1997年制图工作所制定的植被覆盖类型视觉解译词汇表与边界判定方法（资源信息科学研究所，IRIS，1997）。该解译词汇表以关键指示因子进行描述，涵盖颜色、纹理、图案、阴影、大小、形状与景观区位。在解译过程中，分析人员通过查看航空摄影影像、实地踏勘湿地，并频繁与项目合作专家磋商，建立起航空摄影影像特征与地面实际状况之间的关联。植物群落类型的分类基于其主导视觉特征。植被群落类型多边形通过在不同群落间绘制边界线进行定义：当颜色、纹理或其他关键指示因子出现显著变化时，通过描边划定群落边界；当群落特征呈渐变过渡时，则以两种群落组分占比相等的位置作为分界。