Entity and Attribute Overview:
In Version 3.3 a species-based habitat method is implemented by associating each species with a specific set of LULC classes according to the habitat needs of the species. Detailed LULC class delineations allow for an accurate representation of imperiled and special concern species habitat by providing ENSP biologists with the ability to designate a specific set of LULC classes for each individual species-feature label combination. Each species-habitat association is developed by performing a review of scientific literature and/or from information obtained through ENSP research and expert opinion. In addition, a special analysis of the LULC for species and their feature label components was used to guide the selection of particular LULC classes for the creation of species-specific patches of habitat (Appendix IV).
In order to create species-based patches of habitat, the relevant LULC polygons from the Landscape base layer are combined into a potential habitat layer specific to each species-feature label. Spatially explicit species occurrence data that meet the criteria required for inclusion in the Landscape Project are then exported from the Biotics database and a species occurrence area (SOA) is applied for every feature label assigned to a species. SOAs are then overlaid onto species-specific habitat patches and patches are classified, or valued, based on the status of the species present as follows:
Rank 5 is assigned to species-specific habitat patches containing one or more occurrences of wildlife listed as endangered and threatened pursuant to the Federal Endangered Species Act of 1973.
Rank 4 is assigned to species-specific habitat patches with one or more occurrences of State endangered species.
Rank 3 is assigned to species-specific patches containing one or more occurrences of State threatened species.
Rank 2 is assigned to species-specific habitat patches containing one or more occurrences of species considered to be species of special concern. Rank 1 is assigned to species-specific habitat patches that meet habitat-specific suitability requirements such as minimum size or core area criteria for endangered, threatened or special concern wildlife species, but that do not intersect with any confirmed occurrences of such species (see Appendix V for descriptions of all habitat-specific suitability requirements).
Rank 1 habitat patches without documented occurrences are not necessarily absent of imperiled or special concern species. Patches with a lack of documented occurrences may not have been systematically surveyed. Thus, the Rank 1 designation is used for planning purposes, such as targeting areas for future wildlife surveys.
A SOA will value habitat that it overlays only if that habitat is appropriate for the species. Habitat patches ranked 2, 3, 4, or 5 intersect with or contain at least one documented SOA. Since imperiled species are typically not abundant across the landscape, a single occurrence may represent a significant portion of the local population and often indicates the presence of a larger population within a habitat patch. The Landscape Project habitat patch mapping approach is designed to capture and represent the habitat needed to support the local population indicated by the individual SOA.
In the delineation of Species-Based Habitat, each species-feature label combination is grouped into a Patch Type, or category that describes the method employed to form the valued habitat area from polygons in the Landscape base layer. In addition, for each LULC class selected for a particular species-feature label combination, a LULC Treatment, or rule, is applied that determines how polygons of a LULC class will interact with a SOA and/or with polygons of other LULC classes in order to construct patches of habitat. The four general patch types are described below and the LULC Treatments are defined in Appendix V. For those species-feature label combinations that utilize variations, or subtypes, of the four general types, an explanation of the subtype is also included within Appendix V.
Each species-feature label combination is grouped into one of the following patch type categories.
Limited Extent polygons from a select set of LULC classes are valued upon intersection with a SOA. Once the valued habitat area is identified, any internal holes or gaps containing polygons of selected LULC classes are also valued if they are completely enclosed by, and contiguous with, the valued area.
Contiguous Area polygons from a select set of LULC classes are dissolved/combined into contiguous areas and valued upon intersection with a SOA.
Cardinal-Proximate polygons from an initial, or cardinal, set of LULC classes are valued upon intersection with a SOA and then polygons from a second, proximate set of LULC classes are valued based on a spatial relationship (e.g., adjacency) with polygons from the cardinal set of LULC classes and/or a SOA. Once the valued habitat area is identified, any internal holes or gaps containing polygons of selected LULC classes are also valued if they are completely enclosed by, and contiguous with, the valued area.
Stream Centerline stream centerlines are valued upon intersection with a SOA. In Version 3.3 of the Landscape Project, only freshwater mussel species utilize the Stream Centerline patch type, described more thoroughly in the next section.