PARENT SESSION
Oral Session #105: Conservation Ecology: Biodiversity.
Presiding: L. Alonso
Friday, August 9. 9:00 AM to 12:00 PM. Grand Ballroom Central, Radisson.
Biodiversity and land-use change in the American Mountain West.
MAESTAS, JEREMY*,1, KNIGHT, RICHARD1, GILGERT, WENDELL1,2, 1 Colorado State University, Fort Collins, Colorado2 USDA-NRCS Wildlife Habitat Management Institute, Fort Collins, Colorado
ABSTRACT- Private lands in the Mountain West region of the United States are undergoing a profound land-use conversion from agriculture to rural residential (i.e., exurban) development, though little is known about the ecological consequences of this change. Nongovernmental conservation organizations are working with ranchers to keep their lands out of development and in ranching, ostensibly because they believe biodiversity is better protected on ranches than on exurban developments. Presently, there is little scientific support for this belief. We tested the assumptions of this emerging biodiversity protection strategy by comparing avian, mesopredator, and plant communities across the gradient of intensifying rural land uses of protection, livestock ranching, and exurban development. Surveys were done at randomly selected points on each land use in northern Colorado between May and August 2000 and 2001. Seven bird species, known to exploit human-modified environments, reached higher densities on exurban developments than on either ranches or protected areas. Five other bird species reached greater densities on ranches, protected areas, or both of these land uses when compared to exurban developments. Domestic dogs and house cats were encountered frequently and almost exclusively on exurban developments, whereas, coyotes were detected more frequently on ranchlands than exurban developments. Ranches had plant communities with higher native species richness, lower nonnative species richness, and lower nonnative species cover than did the other land uses. Our results, combined with the fact that much of the productive, low elevation land is in private ownership, support the emerging strategy for biodiversity protection. Future conservation efforts to protect the natural heritage of the Mountain West will require a greater focus on the role of private lands.
KEY WORDS: ranching, exurban development, protected areas, biodiversity