Rescaling the Human Footprint: A tool for conservation planning at an ecoregional scale

Measuring and mapping human influence at the global scale suffers from problems of accuracy and resolution. To evaluate the magnitude of this problem we mapped the Human Footprint (HF) for the Northern Appalachian/Acadian ecoregion at a 90-m resolution using best available data on human settlement, access, land use change, and electrical power infrastructure. Such a map measures the magnitude of human transformation of a landscape, scaled between Human Footprint scores of 0 and 100. Comparison with a 1-km resolution Global Human Footprint map revealed similar spatial patterns of human influence. The correlation between HF scores, however, declined with the size of the area compared, with the rank correlation between ecoregional and global HF scores ranging between 0.67 for 100% of the ecoregion and 0.41 for 0.1% of the ecoregion. This indicates that rescaling the map to a finer resolution leads to improvements that increase as the planning area becomes smaller. The map reveals that 46% of the ecoregion has HF ≤ 20 (compared to 59% in the global analysis) and 34% had HF > 40 (compared to 21% in the global analysis). These results demonstrate the benefit of performing region-scale Human Footprint mapping to support conservation-based land use planning at the ecoregional to the local scale. This exercise also provides a data framework with which to model regionally plausible Future Human Footprint scenarios. These and other benefits of producing a regional-scale Human Footprint must be carefully weighed against the costs involved, in light of the region's conservation planning needs.