Ainsworth's salamander

The sixth mass extinction

Duke University biologist Stuart Pimm

Indirect effects of climate change

in 2050,

a half of the species

will become extinct

or endangered.

For example, climate change in local environment would reduce animals’ immune function and lead to the outbreak of pathogen and a rise in mortality rate. Sometimes the changes of surroundings would become more favorable to the growth of pathogen.

Heyer et al discovered in Brazil that five species of frogs would

become extinct without frost.

(Batrachochytrium

dendrobatidis )

Ainsworth's salamander

Habitat destruction

draining of wetlands, logging and development Waterfront.

Each year, 14 million salamanders

die in Appalachian Mountains in

the US because of logging.

Environmental destruction: logging

Literature Cited

Beebee, T. J. C. 1996. Ecology and conservation of amphibians. Chapman and Hall, London, UK.

Bickford, D. et al. (2008) Forgetting Habitat Loss in Amphibian Extinctions- Missing the Forest for the Disease. http://biology.plosjournals.org/perlserv/?request=readresponse&doi=10.1371/journal.pbio.0060072&ct=1 accessed 4/11/2008

Cooper N, Bielby J, Thomas GH, Purvis A (2008) Macroecology and extinction risk correlates of frogs. Global Ecology and Biogeography 17(2): 211-221.

Dahl, T. E. 2000. Status and trends of wetlands in the conterminous United States 1986 to 1997. U.S. Department of the Interior, Fish and Wildlife Service, Washington, D.C. 82 pp.

Dodd, C. K., and L. L. Smith. 2003. Habitat destruction and alteration: historical trends and future prospects for amphibians. Pages 94-112 in R. D. Semlitsch, editor. Amphibian Conservation. Smithsonian Institution, Washington.

FAO (2007). State of the World's Forests. Rome: Food and Agricultural Organization of the United Nations.

Hanski, I. 1999. Metapopulation ecology. Oxford University Press:i-ix, 1-313.

Hedges, S. B. 1993. Global amphibian declines: a perspective from the Caribbean. Biodiversity and Conservation 2:290-303.

Hijmans, R., et al. (2008). Worldclim. http://www.worldclim.org/ accessed 5/4/2008.

IUCN, Conservation International, and NatureServe. (2006) Global Amphibian Assessment. . Downloaded on 11 April 2008.

Mac, M. J., P. A. Opler, C. E. Puckett, and P. D. doran. 1998. Status and trends of the Nation's Biological Resources. Volumes 1 and 2. U.S. Geological Survey, Reston, VI.

Marsh, D. M., and P. C. Trenham. 2001. Metapopulation dynamics and amphibian conservation. Conservation Biology 15:40-49.

Petranka, J. W., M. E. Eldridge, and K. E. Haley. 1993. Effects of Timber Harvesting on Southern Appalachian Salamanders. Conserv Biol 7:363-370.

Stebbins, R. C., and N. W. Cohen. 1995. A natural history of amphibians. Princeton University Press:i-xvi, 1-316.

Environmental destruction: grazing

Examples of habitat changes that may affect amphibian communities

Climate Change

El Nino

global warming

golden toad

Wetland habitats:

� 185,400ha of wetlands lost per year between mid-1950s and mid-1970s

� 117,400 ha of wetlands lost per year between mid-1970s and mid 1980s

� 155,200 ha of wetlands lost to urbanization and rural development between 1986 and 1997.

� 70-90% loss of wetlands in Connecticut, Maryland and Ohio between 1780 and 1980.

� 69% of pocosins of Atlantic Coastal Plain destroyed by 1980.

� 50% loss of everglades ecosystem by the early 1990s; the remainder greatly altered.

� 50 to 60% loss of wetlands in Alabama between 1780 and 1980.

� 54% loss of wetlands in Michigan, Minnesota and Wisconsin.

� 30 to 36% loss of wetlands in Arizona, New Mexico and Utah between 1780 and 1980.

� 91% loss of vernal pools and wetlands gone from California.

� 70% loss of ponds in Britain between 1880 and 1980s

� 82% of marshlands destroyed in Essex County, England, between 1938 and 1981.

� Xenopus gilli has lost 60% of its wetland breeding sites in South Africa due to habitat loss.

Stream and River Habitats

� 98% of the original 5.2 million kilometers of streams in the continental United States have been seriously affected

� 91% of river lengths in lower 48 US states developed by 1988

� 33% of hydrological basins in northeastern United States affected by toxics: 63% by excess nutrients

� 66% of the riparian forest in the United States has been destroyed.

� 85 to 98% of riparian forest in Arizona and New Mexico have been destroyed or severely degraded.

Terrestrial Habitats

� 0.01% of native grasslands remain in pre-European contact condition

� 85 to 98% loss of oldgrowth forest in Blue Ridge and Cumberland Plateau provinces of Tennessee

� 69% of Illinois forests present in 1820 are gone today.

� 60% of old-growth forest on Olympic Peninsula, Washington, is in patches of 40 h or less

� 85% of coastal redwood forest reduced in California

� 0.2% of original forest remains in Puerto Rico

� Forest cover is only 13% of Cuba, 10% of the Dominican Republic, 5% of Jamaica and less than 1% of Haiti because of deforestation.

Amphibian extinction

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