TY - JOUR AU - Casey, Frank AB - Roundtable Noah’s Options: Initial Cost Estimates of a National System of Habitat Conservation Areas in the United States MARK L. SHAFFER, J. MICHAEL SCOTT, AND FRANK CASEY espite the current downturn in the economy, the existing nature reserves (e.g., a preponderance of high altitude, DUnited States has been enjoying a period of unprece- poor soil areas) and the failure of the current system to include dented economic prosperity. At the same time, our biodiversity all at-risk native species and natural community types, has assets are increasingly at risk. Approximately 100 species in the prompted efforts to identify comprehensive systems of habi- United States have become extinct, and fully one-third of tat conservation areas that could represent those ecosystems our native species of vertebrates, flowering plants, and certain and habitats necessary for the survival of at-risk species (Scott invertebrate groups are of conservation concern (Stein et al. et al. 1993, Cox et al. 1994, Defenders of Wildlife 1998, TNC 2000). Roughly half of our natural community types are at 1998, Soulé and Terborgh 1999). Having an ecologically and similar risk, and 27 ecosystems have declined in area by 98 per- taxonomically comprehensive system of nature reserves in the cent or TI - Noah's Options: Initial Cost Estimates of a National System of Habitat Conservation Areas in the United States JF - BioScience DO - 10.1641/0006-3568(2002)052[0439:NSOICE]2.0.CO;2 DA - 2002-05-01 UR - https://www.deepdyve.com/lp/oxford-university-press/noah-s-options-initial-cost-estimates-of-a-national-system-of-habitat-BOBQR2m0Ku SP - 439 EP - 443 VL - 52 IS - 5 DP - DeepDyve ER -