호주
environment_ACTGOV - Riparian Remnant Patches
Urban Habitat Connectivity Project (UHCP) Short description: A package of data containing potential habitat and fragmentation for seven species groups in the urban ACT. Each species group has two layer files. Connected habitat layers show potential core and corridor habitat for the species group, and connectivity/fragmentation between these habitat patches. Remnant patches layers contain areas which are predicted to be fragmented and inaccessible for the species group, but may be important for restoration activities. These layers are outputs of ecological connectivity modelling and have been developed using spatial data representing habitat and connectivity requirements specific to the species group. The following attributes are available in the data table for Connected Habitat layers: Species Group* - indicates the species group of interestPatch ID – a unique identifier for each ‘patch’ of connected habitat, an ID that is given to group all habitat areas which are predicted to be connected to each other.Habitat Type* – identifies if the polygon meets core or corridor habitat requirements, or if it is a remnant patch.Habitat Number – a numeric value linked to Habitat Type to support statistics and symbology. Core habitat has a value of 0 and corridor habitat has a value of 1.Patch Area (Ha)* – the area of the individual polygon in hectares.Connected Habitat Area (Ha) – the total area of potential habitat in the connected patch, determined by summing the Patch Area for all polygons with the same Patch ID.Shape area – the polygon’s area, calculated by default in meters squared.Shape length – the length of the line enclosing the polygon, calculated by default in meters squared. * Is also available in the data table for Remnant Patches layers. Spatial resolution: 1:10,000 Coordinate system: GDA2020 MGA zone 55 METHODS Data collection / creation: Spatial layers for habitat and barriers were created and input into a habitat connectivity/fragmentation model specifically designed for the species group. The model was developed using metrics derived from expert elicitation. These metrics quantified essential habitat and connectivity requirements for the species group, for example the preferred spacing of trees, the maximum crossable width of a road, the typical dispersal distance, etc. The model identified habitat and barriers to connectivity, based on the metrics which could be mapped. Habitat was delineated by patch size to determine core and corridor habitat, and to remove areas which are too small to be functional. The habitat type is visible in the attribute table of the data. Connectivity between habitat patches is dependent on the species group’s dispersal capacity and the availability of core habitat, suitable corridors and a path without barriers. To assess this core habitat areas were buffered by the species group’s dispersal distance. This identified how far an individual will move to find a new core habitat patch. Movement to this distance is dependent on a suitable path. All habitat was buffered by the distance the species can move outside habitat (through non-habitat areas). This identified how far an individual will move outside any habitat (core or corridor) before they require another habitat patch (i.e. how far they can travel between stepping stones).Connectivity is further complicated by impassable barriers. Barriers were used to slice up the dispersal buffers and identify ‘dispersal patches’, areas which an individual can move within. Fragmentation is seen when a barrier is present, patches are too far from core habitat, or corridor habitat is too far apart. A unique ID was applied to each patch and represents connectivity/fragmentation. The patches were intersected with habitat to apply the new ID to the habitat areas. The final model outputs identify areas of potential core, corridor or remnant (inaccessible) habitat. Core and corridor habitat are viewable in the connected habitat dataset, whilst remnant patches