The next 50 years: Opportunities for diversifying the ecological representation of the National Wilderness Preservation System
The National Wilderness Preservation System (NWPS) encompasses the largest protected area network in the country, yet fails to represent all ecological systems available on federal land. The Wilderness Act (1964) established a process for adding lands to the NWPS, and to strategically safeguard the remaining intact habitat areas over the next 50 years, we need to identify the best opportunities to diversify ecological representation within it. Over the last few decades, additions to the NWPS have not greatly increased ecological representation, but rather have maintained the bias toward high-altitude and low-productivity areas.
Much opportunity remains, however, to increase diversity by bringing eligible roadless federal lands into the designated wilderness system. We simulated the change in diversity and representation of ecological systems by adding candidate wilderness areas, specifically 1) all National Park lands that have yet to be designated wilderness; 2) lands that have been studied by Congress or recommended by federal land management agencies for possible wilderness designation; 3) all US Forest Service inventoried roadless areas; and 4) all roadless lands managed by the Bureau of Land Management (BLM).
An expanded NWPS would include 48.3% of all federal lands, diversify NWPS by adding 46 ecological systems, and nearly triple the number of ecological systems with at least 20% of their federal land area designated as wilderness (from 113 to 309). Including National Park lands described above as wilderness added 39 ecological systems—the most of any category; furthermore, 82 more ecological systems would cross the “well-represented” threshold of 20% of federal land designated as wilderness. In contrast, designating the lands currently managed as wilderness (but not yet designated) would add only 3 ecological systems, and only 14 additional ecological systems would have >20% representation within NWPS. Even if all our land designation categories were included in the NWPS, there would still be 64 unique ecological systems on federal land completely un-represented in wilderness. Having the highest representation of ecological systems possible within an expanded NWPS will be vital for preserving the diversity of species and habitats found throughout the US and will provide the most robust NWPS possible for adapting to short and long-term land-use and climate change in the future.