Abstract
The threat of anthropogenic climate change has seen a renewed focus on understanding contemporary patterns of species distribution. This is especially the case for the biota of tropical mountains, because tropical species often have particularly narrow elevational ranges and there are high levels of short-range endemism. Here we describe geographic patterns of ant diversity and distribution in the World Heritage-listed rainforests of the Australian Wet Tropics (AWT), revealing seasonal moisture stability to be an important environmental correlate of elevational patterns of species composition. We sampled ants in leaf litter, on the litter surface and on tree trunks at 26 sites from six subregions spanning five degrees of latitude and elevation ranges from 100-1,300 m. A total of 296 species from 63 genera were recorded. Species richness showed a slight peak at mid elevations, and did not vary significantly with latitude. Species composition varied substantially between subregions, and many species have highly localised distributions. There was very marked species turnover with elevation, with a particularly striking compositional disjunction between 600 m and 800 m at each subregion. This disjunction coincides with a strong environmental threshold of seasonal stability in moisture associated with cloud 'stripping'. Our study therefore provides further support for climatic stability as a potential mechanism underlying patterns of diversity. The average height of orographic cloud layers is predicted to rise under global warming, and associated shifts in seasonal moisture stability may exacerbate biotic change caused by rising temperature alone.
| Original language | English |
|---|---|
| Article number | e0153420 |
| Pages (from-to) | 1-20 |
| Number of pages | 20 |
| Journal | PLoS One |
| Volume | 11 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Apr 2016 |
| Externally published | Yes |
Bibliographical note
Funding Information:Stephen Williams played a key role in establishing the project. Jodie Hayward, Magen Pettit, Célénie Christophe, Maxence Plouviez, Antoine Esnouf, Clémence Roldan, Carina Svensson and Arnaud Gourret provided valuable field and laboratory assistance, and Nick Nicholls gave valuable advice on R software. We thank them all. SN was supported by a PhD scholarship from the National Environmental Research Program of Australian Government.
Publisher Copyright:
© 2016 Nowrouzi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
