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Ecological specialization and population size in a biodiversity hotspot: How rare species avoid extinction
Citation
Williams, SE and Williams, YM and VanDerWal, J and Isaac, JL and Shoo, LP and Johnson, CN, Ecological specialization and population size in a biodiversity hotspot: How rare species avoid extinction, National Academy of Sciences of The United States of America. Proceedings, 106, (Supplement 2) pp. 19737-19741. ISSN 0027-8424 (2009) [Refereed Article]
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Copyright Statement
PNAS Copyright © 2009 by the National Academy of Sciences
DOI: doi:10.1073/pnas.0901640106
Abstract
Species with narrow environmental niches typically have small
geographic ranges. Small range size is, in turn, often associated
with low local abundance. Together, these factors should mean
that ecological specialists have very small total populations, put-
ting them at high risk of extinction. But some specialized and
geographically restricted species are ancient, and some ecological
communities have high proportions of rare and specialized endem-
ics. We studied niche characteristics and patterns of distribution
and abundance of terrestrial vertebrates in the rainforests of the
Australian Wet Tropics (AWT) to identify mechanisms by which
rare species might resist extinction. We show that species with
narrow environmental niches and small geographic ranges tend to
have high and uniform local abundances. The compensation of
geographic rarity by local abundance is exact, such that total
population size in the rainforest vertebrates of the AWT is inde-
pendent of environmental specialization. This effect would tend to
help equalize extinction risk for specialists and generalists. Phylo-
genetic analysis suggests that environmental specialists have been
gradually accumulating in this fauna, indicating that small range
size/environmental specialization can be a successful trait as long
as it is compensated for by demographic commonness. These
results provide an explanation of how range-restricted specialists
can persist for long periods, so that they now form a major
component of high-diversity assemblages such as the AWT.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Research Division: | Biological Sciences |
| Research Group: | Ecology |
| Research Field: | Community Ecology |
| Objective Division: | Environment |
| Objective Group: | Flora, Fauna and Biodiversity |
| Objective Field: | Forest and Woodlands Flora, Fauna and Biodiversity |
| Author: | Johnson, CN (Professor Christopher Johnson) |
| ID Code: | 72187 |
| Year Published: | 2009 |
| Web of Science® Times Cited: | 41 |
| Deposited By: | Zoology |
| Deposited On: | 2011-08-23 |
| Last Modified: | 2012-03-06 |
| Downloads: | 0 |
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