The Vermont Fish and Wildlife Department's Natural Heritage Inventory (NHI) maintains a database of uncommon, rare, threatened and endangered species and natural (plant) communities in Vermont. The Department is a member of the network of Natural Heritage Programs and Conservation Data Centres network that collaborates with NatureServe, which is the umbrella organization. The uncommon species and and other features data is from the Natural Heritage Inventory database and include information on the location, status, characteristics, numbers, condition, and distribution of elements of biological diversity using established Natural Heritage Methodology developed by NatureServe and The Nature Conservancy. The data is largely composed of uncommon species data (S3 Rank), but may also include poorly documented rare species (S1 or S2 Rank) or potentially significant natural communities. The data come from two Natural Heritate Inventory database tables: Element Occurrences and Independent Source Features. Element Occurrence (EO) is an area of land and/or water in which a species or natural community is, or was, present. An Independent Source Feature (SF) is an observation of a species or natural community but lacks the detailed information and has not been turned into an EO. On the other hand, an EO should have practical conservation value for the Element as evidenced by potential continued (or historical) presence and/or regular recurrence at a given location. For species Elements, the EO often corresponds with the local population, but when appropriate may be a portion of a population or a group of nearby populations (e.g., metapopulation). For community Elements, the EO may represent a stand or patch of a natural community, or a cluster of stands or patches of a natural community. Because they are defined on the basis of biological information, EOs may cross jurisdictional boundaries. An Element Occurrence record is a data management tool that has both spatial and tabular components including a mappable feature and its supporting database. EOs are typically represented by bounded, mapped areas of land and/or water or, at small scales, the centroid point of this area. EO records are most commonly created for current or historically known occurrences of natural communities or native species of conservation interest.
