AUTHORS: Rose A. Graves*, Boise State University; Matthew A. Williamson, University of California-Davis & The Center for Large Landscape Conservation; Travis Belote, The Wilderness Society; Jodi Brandt, Boise State University
ABSTRACT: The most pressing conservation issues in North America require conservation approaches that span large landscapes. Public protected areas (PPAs) in the United States do not currently protect many ecosystems or larger scale ecological processes. Increasingly, conservation easements (CE) are used as a tool to protect private land from future development; yet, few studies have examined whether contemporary patterns of CEs effectively contribute to landscape-scale biodiversity and ecosystem conservation goals. Using a database of 1237 CEs established from 1970 to 2016, we analyzed the spatial pattern and conservation value of private-land conservation in the High Divide, a region dominated by public lands and critical to ecological connectivity in the Rocky Mountains. Specifically, we asked 1) how does the spatial distribution of CEs differ from non-protected private lands?; 2) how well are ecological systems (i.e., vegetation communities) and biodiversity (i.e., vertebrate species) represented in CEs relative to their occurrence in the region?; and 3) how well do CEs maintain landscape-scale ecological connectivity relative to unprotected private land? We found that CEs comprised 9.1% (4853 km2) of the private land area and 3.6% of the total land area in the High Divide. Compared to random private land locations, CEs were more likely to be found in lower elevations and nearer to water bodies and PPAs. Despite small areal coverage, CEs contribute disproportionately to conservation of 30% of vegetation communities in the region and, importantly, provided complementary protection for habitat types underrepresented in PPAs. Private land in the High Divide is important for connectivity between PPAs but mean connectivity score was not different between CEs (M=0.79, sd=0.10) and unprotected private land (M=0.75, sd=0.11). Our study suggests that private land conservation contributes substantially to landscape-scale conservation goals, and that current patterns of CE provide complementary conservation value to PPAs.