Priority Locations for Conservation Action - 1:250,000 Hydrological Units

This is a map of priority locations for conservation action. Each hydrological unit (or watershed) is assigned a priority rank based on the conservation importance (irreplaceability) of the conservation values found in the hexagon, and the threat to those values from human development. This approach is based on a study conducted in the Greater Yellowstone region by Reid Noss at colleagues (Noss et al. 2002).

An Irreplaceability score for each hydrological unit was assigned using the conservation values identified by the Ecoregional Assessment conducted by TNC and NCC, and the focal species distribution models for lynx, marten and wolf developed by the Wildlands Network. To calculate irreplaceability the site selection software MARXAN was used to calculate scores for 10km2 hexagon planning units. Irreplaceability scores were then derived for each hydrological unit using an area weighted mean calculation.

The Threat score for each hydrological unit was calculated as the mean score of the CurrentHuman Footprint and three scenarios Future Human Footprint, resulting in four threat scores per planning unit. The cutoff between High irreplaceability and Low irreplaceability was set as the median value (61) of the Irreplaceability scores, while the cutoff between High and Low vulnerability was assigned as the median of the Current Human Footprint values (21).

This map highlights the hydrological units that are currently identified as highly irreplaceable / low threat that are at risk of transitioning to a level of high threat in the future under one under one of the Future Human Footprint Scenarios. CT = FHF Current Trends Scenario, NCL = FHF Rapid Growth North Central Lakes, PNW = FHF Rapid Growth - Pacific Northwest.

This map of priority locations for conservation action is the result of the 2C1Forest Ecoregional Status and Trend Initiative conducted by the 2C1Forest Science Working Group. Find out more by reading the full report. Trombulak, S.C., M.G. Anderson, R.F. Baldwin, K. Beazley, J.C. Ray, C. Reining, G. Woolmer, C. Bettigole, G. Forbes, and L. Gratton. 2008. The Northern Appalachian/Acadian Ecoregion: Priority Locations for Conservation Action. Two Countries, One Forest / Deux Pays, Une Foret Special Report 1.

The Hydrologic units of the Northern Appalachian/Acadian ecoregion were compiled from U.S. HUC 8 drainage units and Canadian sub-sub-drainage areas . The ecoregion contains 147 hydrologic units, ranging in size from 1.5 km2 to 8,988 km (mean area of 2,355 km2).