Western Governors' Association Connectivity Zones and Large Intact Blocks

The important connectivity zones (ICZ) data layer represents linear landscape paths that were created by identifying segments of centrality (or flowlines) based on a human footprint/landscape condition dataset as a cost surface. The ICZs were identified independent of a to/from block and instead analyzed every pixel for a least cost path to every other pixel. Pixels (and paths) that were repeatedly identified as good routes produced high centrality scores and were identified as ICZs. Connectivity zones were identified for each of the 7 biomes that occur across the west (see documentation refered to below). Once the centrality flowlines for each biome were identified, a series of process were performed to create the connectivity zones dataset. 1) flowlines that intersected 1 or more biome relevant Large Intact Blocks (LIB) with a minimum centrality score of 6 were identified and the start/end points were determined. Biome relevant LIBS are those LIBS that are dominated (>50% area) by the same biome that was used to calculate flowlines. 2) A “least cost path” was calculated by summing the cost distance between segment start/end points. 3) A 1-mile buffer (each side) of the least cost path was calculated and designated as an ICZ. The ICZ was then attributed with the Euclidean distance of its length between LIBs, ecological (cost weighted by human footprint) distance, the segments mean centrality score. The attributes of distance, cost/weight, and centrality scores were used to ranking the corridor zones. Connectivity zones with the highest centrality, shortest distance and highest landscape condition were ranked highest (ICZ score 1). Connectivity zones that had low centrality, were especially long, and scored lowest in landscape condition given a ICZ score of 3. All other zones were given an ICZ score of 2(See referenced document below for more details). Ranking were calculated with attention being paid to what biome types they connected so emphasis was place on connecting similar type biomes (i.e. grasslands to grasslands over grasslands to alpine). Once scored for each biome type, the connectivity zones were intersected with the WGA hexagons and scored with the highest biome corrior score for that hexagon. Hexagons were then dissolved based on the Final corridor score. This data layer is one of three that were produced to support the WGA Wildlife Council Landscape Integrity Working Group. The intent of these work products are to provide individual states with information on current landscape condition, significant large intact blocks and important connectivity zones mapped across the state and regional boundaries. These data may or may not be used by each state in the development of a state’s final crucial habitat map. States may choose to supplement or replace the work group data with other data sources that may be available only for their state (and neighboring states). The final crucial habitat maps were published in December of 2013, and data the states use of these data in creating their crucial habitat maps may change over time, thus necessitating subsequent updates. As potential users of these data you are encouraged to talk with each state to further identify any additional concerns a state may have or updated data layers that are produced subsequent to the publication date of these layers. For more information on the Corridor Zones dataset, see: Technical documentation of the process to identify Corridor Zones. David M. Theobald, PhD. Department of Fish, Wildlife, and Conservation Biology. Colorado State University.For more information on the ranking and scoring of connectivity zones see WGA Landscape Integrity Workgroup Recommendations, unpublished report to WGA Wildlife Council State Technical Team dated 02/12/2013.The Large Intact Blocks (LIB) dataset was calculated from the NatureServe Landscape Condition model as a way to identify large areas that were relatively intact or had low levels of anthropogenic impacts. Large Intact Blocks (LIBs) were derived directly from the landscape Condition scores similar to the methods used by the Washington Habitat Connectivity Working Group, as implemented in the Habitat Core Area tool (WHCWG 2010). Each LIB was binned into three levels of importance, based on relative level of intactness in its ecodivision and its total area. LIBs with the highest third of mean LC values regardless of size were ranked as level 1. LIBs that were 10,000-50,000 ha in size that were not classified as Level 1 were classified as Level 3 importance. All remaining LIBs were classified as Level 2 importance.This data layer is one of three that were produced to support the WGA Wildlife Council Landscape Integrity Working Group. The intent of these work products are to provide individual states with information on current landscape condition, significant large intact blocks and important connectivity zones mapped across the state and regional boundaries. These data may or may not be used by each state in the development of a state’s final crucial habitat map. States may choose to supplement or replace the work group data with other data sources that may be available only for their state (and neighboring states). The final crucial habitat maps (Version 1) were published in December of 2013, and data the states use of these data in creating their crucial habitat maps may change over time, thus necissitating subsequent updates. As potential users of these data you are encouraged to talk with each state to further identify any additional concerns a state may have or updated data layers that are produced subsequent to the publication date of these layers. For more information see the accompanying documentation, LIB_methods.pdf and WGA Landscape Integrity Workgroup Recommendations, unpublished reports to WGA Wildlife Council State Technical Team dated 02/12/2013.