Australian deserts are diversity-hotspots for lizards, according to research by Gary Powney and colleagues. Powney, who is a PhD student based jointly at the Centre for Ecology & Hydrology and Imperial College London, mapped the species richness of Australian lizards, concluding that it was strikingly different from the richness patterns of mammals, amphibians and birds in the country.
The findings are published in the journal Global Ecology and Biogeography.
In order to understand the richness pattern of Australian lizards, Powney and colleagues compiled a database of published distribution maps of 625 species of lizards, calculating the number of lizard species found in one degree grid cells across Australia. The highest concentration of lizard species, a maximum of 94 species per cell, was found to run from central Australia west to the Hamersley Range and Pilbara coast, an area not well known for its biodiversity. The lowest concentration, minimum of 27 species per cell, was found in the lowlands between the central deserts and the Great Dividing Range.
“Conserving mammal, amphibian and bird biodiversity hotspots does not necessarily protect lizard diversity as well as it could." Gary Powney
The research compared the species richness maps with four environmental variables: temperature, altitude, moisture and habitat diversity. Powney said, “We found that lizards are most species-rich in the hot and arid regions while the other vertebrates prefer more moist regions.”
This new research suggests that the conservation of biodiversity hotspots of one group of species may not conserve the hotspots of other groups.
“Lizard diversity has a strikingly different distribution compared to mammals, birds and amphibians,” added Powney “This means that conserving mammal, amphibian and bird biodiversity hotspots does not necessarily protect lizard diversity as well as it could.”
Results from this study form part of a larger reptile biogeography and biodiversity conservation project involving the assessment of all reptile distributions around the world.
The study is published in Global Ecology and Biogeography (subscription may be required). The full citation is: G.D. Powney, R. Grenyer, C.D.L. Orme, I.P.F. Owens, S. Meiri. Hot, dry and different: Australian lizard richness is unlike that of mammals, amphibians and birds. Global Ecology and Biogeography, published online 19 March 2010. doi:10.1111/j.1466-8238.2009.00521.x