[MCN] WILDERNESS: All the disturbed habitats put together include 41% fewer species than the undisturbed forests.

[Lance Olsen]

PNAS 2017 ; published ahead of print May 1, 2017, doi:10.1073/pnas.1611855114
Biological Sciences - Ecology:

Effects of habitat disturbance on tropical forest biodiversity
John Alroy

Significance

Biologists believe that a major mass extinction is happening in the tropics. Destruction of forests is a key reason. However, there are no solid predictions of the percentage of species that will go extinct as more and more forests are disturbed. This paper provides estimates based on extrapolating the respective numbers of species in disturbed and undisturbed habitats. It uses a large global database of species inventories at particular sites. Trees and 10 groups of animals are analyzed. All the disturbed habitats put together include 41% fewer species than the undisturbed forests. This proportion varies among groups but is always substantial. Furthermore, disturbed local communities are dominated by widespread species such as rats and electric ants.

Abstract
http://www.pnas.org/content/early/2017/04/25/1611855114.abstract <http://www.pnas.org/content/early/2017/04/25/1611855114.abstract>
It is widely expected that habitat destruction in the tropics will cause a mass extinction in coming years, but the potential magnitude of the loss is unclear. Existing literature has focused on estimating global extinction rates indirectly or on quantifying effects only at local and regional scales. This paper directly predicts global losses in 11 groups of organisms that would ensue from disturbance of all remaining tropical forest habitats. The results are based on applying a highly accurate method of estimating species richness to 875 ecological samples. About 41% of the tree and animal species in this dataset are absent from disturbed habitats, even though most samples do still represent forests of some kind. The individual figures are 30% for trees and 8–65% for 10 animal groups. Local communities are more robust to disturbance because losses are partially balanced out by gains resulting from homogenization.

deforestation <http://www.pnas.org/search?fulltext=deforestation&sortspec=date&submit=Submit&andorexactfulltext=phrase> lambda-5 index <http://www.pnas.org/search?fulltext=lambda-5+index&sortspec=date&submit=Submit&andorexactfulltext=phrase> mass extinction <http://www.pnas.org/search?fulltext=mass+extinction&sortspec=date&submit=Submit&andorexactfulltext=phrase> multiton subsampling <http://www.pnas.org/search?fulltext=multiton+subsampling&sortspec=date&submit=Submit&andorexactfulltext=phrase> species extinction <http://www.pnas.org/search?fulltext=species+extinction&sortspec=date&submit=Submit&andorexactfulltext=phrase>

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William Bevan, “The Sound of the Wind That’s Blowing.”

American Psychologist. July 1976

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