Landscape Intactness Index for the Western United States

We developed a multiscale index of landscape intactness for use as a broad-scale indicator of resource condition for the Bureau of Land Management’s (BLM) Landscape Approach, which requires multiple scales of information to quantify the cumulative effects of land use. The multiscale index of landscape intactness represents a gradient of anthropogenic influence as represented by development levels at two analysis scales. To calculate landscape intactness we combined the terrestrial development index (TDI) summarized at two scales (using a 2.5- and a 20-km radius circular moving window). To evaluate landscape intactness levels on public lands, we focused on TDI scores less than or equal to 3 percent, which represents relatively low levels of development on multiple-use lands managed by the BLM and other land management agencies. The highest landscape intactness level corresponds to development index scores equal to 0 to 1 percent at both scales. Very-high landscape intactness corresponds to development index scores equal to 0 to 1 percent at one scale and 1 to 2 percent at the other scale. High landscape intactness corresponds to development index score equal to 1 to 2 percent at both scales. Moderate landscape intactness corresponds to development index score equal to 2 to 3 percent at one scale and less than 3 percent at the other scale. The lowest landscape intactness corresponds to development index scores greater than 3 percent at either scale. The multiscale index of landscape intactness is designed to be flexible, transparent, defensible, and applicable across multiple spatial scales, ecological boundaries, and jurisdictions. The standardized index is intended to serve as one of the proposed core metrics to quantify landscape integrity for the BLM Assessment, Inventory, and Monitoring program. The multiscale index is designed to be used in conjunction with additional regional- or local-level information not available at national levels, such as invasive species occurrence, necessary to evaluate ecological integrity.