Habitat Fragments

This layer was created as part of Esri’s Green Infrastructure Initiative and is one of five newly generated companion datasets that can be used for Green Infrastructure (GI) planning at national, regional, and more local scales. If used together, these layers should have corresponding date-based suffixes (YYYYMMDD). The corresponding layer names are: Intact Habitat Cores, Habitat Connectors, Habitat Fragments, Habitat Cost Surface, and Intact Habitat Cores by Betweeness. These Esri derived data, and additional data central to GI planning from other authoritative sources, are also available as Map Packages for each U.S. State and can be downloaded from the Green Infrastructure Data Gallery. Habitat fragments are minimally disturbed natural areas that were not included in the Intact Habitat Cores layer because they did not meet the minimum requirements related to size, minimum thickness, and/or the centroid of a cell fell outside the inner habitat core edge buffer. They are typically smaller than 100 acres in size and/or less than 200 meters wide and often highlight narrow riparian corridors. Habitat fragments can comprise a large portion of the landscape’s surface in areas significantly fragmented by roads, railroads, agriculture and other human dominated activities. While smaller than a core, these areas may represent highly valuable local GI assets in that they may improve ecosystem functions of neighboring cores, serve as green infrastructure building blocks in highly fragmented landscapes void of cores, provide stepping stones for facilitating local connectivity, and pose opportunities for habitat restoration among others. Data Coordinate System: NAD_1983_Albers本图层由Esri绿基础设施倡议开发，是五个新生成的配套数据集之一，可用于国家、区域及更微观尺度的绿基础设施（Green Infrastructure, GI）规划。若联合使用此类图层，需为其添加对应的日期后缀（YYYYMMDD）。对应的图层名称分别为：完整生境核心区（Intact Habitat Cores）、生境连接通道（Habitat Connectors）、生境碎片区（Habitat Fragments）、生境成本表面（Habitat Cost Surface）以及基于介数的完整生境核心区（Intact Habitat Cores by Betweeness）。 此类由Esri衍生的数据，以及其他权威来源中对绿基础设施规划至关重要的补充数据，均以针对美国各州的地图包（Map Packages）形式提供，可从绿基础设施数据图库（Green Infrastructure Data Gallery）下载。 生境碎片区是指受人类干扰程度极低的自然区域，因未满足尺寸、最小厚度阈值，或其栅格单元的质心落在生境核心内部边缘缓冲区之外，未被纳入完整生境核心区图层。此类区域的面积通常小于100英亩，或宽度不足200米，且多为狭长的河岸廊道。在受道路、铁路、农业及其他人类主导活动严重破碎化的区域，生境碎片区可能占据景观表面的较大比例。 尽管其规模小于核心生境斑块，但此类区域可成为极具价值的本地绿基础设施资产：它们能够改善邻近核心区的生态系统功能，在缺乏核心生境的高度破碎化景观中充当绿基础设施的构建单元，为促进本地连通性提供踏脚石生境，同时还为栖息地修复等工作提供诸多契机。 数据坐标系：NAD_1983_Albers