Assessing risk of large-scale habitat conversion in lightly settled landscapes

Conversion of relatively “wild” areas constitutes a rising threat to the ecological integrity of North American landscapes. As developers seek unprotected, amenity-rich lands, conservation planners require methods to recognize risk and prioritize actions. Most development models and processes are incremental, accumulating change over time and space. By contrast, large-scale amenity development can be rapid and extensive, necessitating “rapid assessment” techniques. For undeveloped lakeshores in the Northern Appalachian/Acadian ecoregion (330 000 km²), we developed a geospatial screening process based on four factors: (1) urban area proximity, (2) attractiveness of amenity (size), (3) regulatory gaps in protection, and (4) likelihood that owners will develop. To assess conversion risk, we added developable zones to the 10 783 large lakes and ponds in the ecoregion and assessed risk to these lands based on four factors at two distances from 15 major urban areas in the region. Thirty-eight of 387 landowners were classified most likely to convert their lands through development, and 11 of these accounted for 97.5% of the total high-risk habitat area (625–1118 km²). Nearly all of the at-risk land (94.6%) lay outside of currently settled areas and most (69.1%) under the purview of a single regulatory agency, the Land Use Regulatory Commission of Maine (LURC). Without rigorous planning by such agencies large-scale, highly dispersed, and rapid conversion of lightly settled, amenity-rich forestland threatens habitat degradation at multiple spatial scales, i.e., local ecosystems themselves (e.g., lakes), surrounding landscapes, and regions.