Criterion 1: Conservation of biological diversity - Indicator 7: The status (threatened, rare, vulnerable, endangered, or extinct) of forest dependent species at risk of not maintaining viable breeding populations, as determined by legislation or scientific assessment

Abstract

As the number of species classified as rare increases, the likelihood of species extinction also increases. This indicator focuses on species that have the greatest chance of being lost from the biotic community and therefore presages potential declines in species richness. The trend in species extinction since the turn of the 20th century varies by taxonomic group. Very few species of crustaceans, amphibians, or mammals, and no reptiles, are known to have become extinct in the last 100 years. Birds are prominent on the list of extinct species, but their numbers have remained fairly constant since the early 1900s. In contrast, the number of insects, mollusks, fish, and vascular plants considered to have become extinct has increased over time. When considering trees and species of terrestrial animals associated with forest habitats, 15 percent are currently at risk of extinction. Proportionately, most of those at-risk forest-associated species are amphibians, butterflies, and grasshoppers. The at-risk species associated with forest habitats are concentrated geographically in Hawaii, in the Southeast, and on the West Coast.

Citation

Flather, Curtis H.; Ricketts, Taylor H.; Sieg, Carolyn Hull; Knowles, Michael S.; Fay, John P.; McNees, Jason. 2003. Criterion 1: Conservation of biological diversity - Indicator 7: The status (threatened, rare, vulnerable, endangered, or extinct) of forest dependent species at risk of not maintaining viable breeding populations, as determined by legislation or scientific assessment. In: Darr, David R., coordinator. Data Report: A Supplement to the National Report on Sustainable Forests -- 2003. FS-766A. Washington, DC: USDA Forest Service, Research & Development. Online: http://www.fs.fed.us/research/sustain/