Douglas J. Shinneman, John Watson, and William W. Martin

The Southern Rockies Ecoregion contains a rich diversity of native plants, animals, and natural communities. However, the ecoregion has not escaped human-caused biological degradation. Several species native to the Southern Rockies have been extirpated and hundreds more are considered to be of conservation concern, including at least 20 species listed as Threatened and Endangered under the Endangered Species Act (ESA). To address this problem, we used a Geographic Information System (GIS) and employed methods similar to those used by the U.S. GAP Analysis Program to assess the relationship between the ecoregion's land protection status (e.g., national parks) and its major ecosystem types, in order to determine the relative level of ecosystem type protection. We then examined the ecosystem type content of the ecoregion's remaining unprotected roadless lands, to determine what conservation values these areas might hold. We also examined slope, elevation, and known locations of rare and imperiled species occurrences in both analyses. The results demonstrate that a general disparity in protection levels exists in the Southern Rockies between biologically-rich, lower-elevation ecosystem types and less species-rich, higher-elevation ecosystems. Only 31% of the collective protected land area is below 10,000 feet in elevation, and only 3 of 13 major ecosystem types native to the Southern Rockies have more than 10% of their total area within protected lands. In addition, the vast majority of rare and imperiled species occurrences lie within less-protected land ownership types, such as multiple-use public lands and private lands. Unprotected roadless areas in contrast contain a significantly higher proportion (62%) of collective land area below 10,000 feet in elevation. By permanently protecting these roadless areas, 11 of 13 native ecosystem types could be represented in protected areas above a 10% level, 5 of 13 could be protected above a 25% level, and hundreds of additional rare and imperiled species locations would be included. While additional analysis is required, roadless area protection may also fulfill additional reserve selection and design criteria that complement representation objectives, including protecting special biological elements (e.g., biodiversity hotspots), meeting the needs of focal species (e.g., wide-ranging carnivores), and establishing habitat connectivity. These results also demonstrate the importance of the Clinton administration's recent proposal to provide formal protection for the nation's remaining unprotected national forest roadless lands. The findings presented in this report are also included in the State of the Southern Rockies Ecoregion.