Vascular plant extinction in the continental United States and Canada |
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| Authors: | Wesley M Knapp Anne Frances Reed Noss Robert F C Naczi Alan Weakley George D Gann Bruce G Baldwin James Miller Patrick McIntyre Brent D Mishler Gerry Moore Richard G Olmstead Anna Strong Kathryn Kennedy Bonnie Heidel Daniel Gluesenkamp |
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| Institution: | 1. North Carolina Natural Heritage Program, Asheville, NC, 28805 U.S.A.;2. NatureServe, 2550 South Clark Street, Suite 930, Arlington, VA, 22202-3926 U.S.A.;3. Florida Institute for Conservation Science, 112 Half Moon Trail, Melrose, FL, 32666 U.S.A.;4. Institute of Systematic Botany, New York Botanical Garden, 2900 Southern Blvd., Bronx, NY, 10458-5126 U.S.A.;5. Biology Department, North Carolina Botanical Garden, University of North Carolina at Chapel Hill, Campus Box 3280, Chapel Hill, NC, 27599-3280 U.S.A.;6. The Institute for Regional Conservation, 100 E. Linton Blvd. #302B, Delray Beach, FL, 33483 U.S.A.;7. Jepson Herbarium & Department of Integrative Biology, University of California, 1001 Valley Life Sciences Bldg. #2465, Berkeley, CA, 94720-2465 U.S.A.;8. Missouri Botanical Garden, 4344 Shaw Blvd., St. Louis, MO, 63110 U.S.A.;9. University and Jepson Herbaria & Department of Integrative Biology, University of California, 1001 Valley Life Sciences Bldg. #2465, Berkeley, CA, 94720-2465 U.S.A.;10. National Plant Data Team, United States Department of Agriculture, 2901 East Gate City Blvd., Suite 2100, Greensboro, NC, 27041 U.S.A.;11. Department of Biology and Burke Museum, University of Washington, Seattle, WA, 98195 U.S.A.;12. Texas Parks and Wildlife Department, 4200 Smith School Road, Austin, TX, 78744 U.S.A.;13. United States Forest Service, 333 Broadway Blvd. SE, Albuquerque, NM, 87102 U.S.A.;14. Wyoming Natural Diversity Database, University of Wyoming, 1000 E. University Avenue, Laramie, WY, 82071 U.S.A.;15. California Native Plant Society, 2707 K Street, Suite 1, Sacramento, CA, 95816 U.S.A. |
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| Abstract: | Extinction rates are expected to increase during the Anthropocene. Current extinction rates of plants and many animals remain unknown. We quantified extinctions among the vascular flora of the continental United States and Canada since European settlement. We compiled data on apparently extinct species by querying plant conservation databases, searching the literature, and vetting the resulting list with botanical experts. Because taxonomic opinion varies widely, we developed an index of taxonomic uncertainty (ITU). The ITU ranges from A to F, with A indicating unanimous taxonomic recognition and F indicating taxonomic recognition by only a single author. The ITU allowed us to rigorously evaluate extinction rates. Our data suggest that 51 species and 14 infraspecific taxa, representing 33 families and 49 genera of vascular plants, have become extinct in our study area since European settlement. Seven of these taxa exist in cultivation but are extinct in the wild. Most extinctions occurred in the west, but this outcome may reflect the timing of botanical exploration relative to settlement. Sixty-four percent of extinct plants were single-site endemics, and many occurred outside recognized biodiversity hotspots. Given the paucity of plant surveys in many areas, particularly prior to European settlement, the actual extinction rate of vascular plants is undoubtedly much higher than indicated here. |
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| Keywords: | conservation extinction rate rarity single-site endemics taxonomy conservación endemismos de sitio único rareza tasa de extinción taxonomía |
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