Kennedy et al. (2019) provided a cumulative measure of

human modification of terrestrial lands based on modeling the physical extents of 13 anthropogenic stressors and their estimated impacts using spatially explicit global datasets with a median year of 2016. They quantified the degree of land modification and the amount and spatial configuration of low modified lands (i.e. natural areas relatively free from human alteration)across all ecoregions and biomes. We reclassified this layer based on the lower third (.33) of the least modified places, converted to a polygon, and used this as a third indicator of structural

intactness.