High conservation value areas on BLM lands in 11 western states

The dataset includes values of network flow (betweenness) centrality, effective resistance, and combined connectedness to the existing network of protected areas (PAs). Details can be found in Dickson et al. (in press).

The high conservation value areas were defined by a systematic analysis of seven ecological indicators on contiguous areas of roadless BLM land. The indicators used to define these areas included species richness, vegetation community diversity, surface water availability, topographic complexity, landscape naturalness and permeability, and level of ecoregional protection. They were combined using methods described in detail in Dickson et al. (2014) and represent the “80/20 scale-dependent core” results from that analysis.

Flow centrality values were calculated for each high conservation value area as the total current flow per square kilometer. Current flow was estimated using Circuitscape software and a resistance layer based on the degree of human modification and other variables, and using the existing network of PAs as defined by the US PA Database v1.3 (USGS 2012). Each PA centroid was connected to ground and 1 Amp of current was injected in the remaining centroids. Current flow was the sum of these estimates across all PAs. Current flow data and details are provided and described by Dickson et al. (2016), available on Databasin.

Effective resistance to the existing PA network was calculated using Circuitscape and the same input layers by setting all PAs to ground and iteratively injecting 1 Amp of current into each high conservation value area.

Combined rankings were calculated by adding the rankings for flow centrality (from high to low) and effective resistance (from low to high) for each high conservation value area.

Methods are described in more detail in Dickson et al. (in press).

Full metadata can be viewed upon download in the file named 'metadata1_original.xml'