Temporal and distributional patterns of terrestrial arthropods in the Pilbara region of Western Australia

Research project: Temporal and distributional patterns of terrestrial arthropods in the Pilbara region of Western Australia

Start date:: 2004

Museum investigators

John Gollan, Scientific Officer
Mick Ashcroft, Spatial Analyst
Dan Faith, Principal Research Scientist
Scott Ginn, Technical Officer

External investigators

Gerry Cassis, University of New South Wales
Gareth Carter, New South Wales Rural Fire Service
Scott Lassau, New South Wales National Parks and Wildlife Service
Andrew Donnelly, Earthwatch Institute
Matthew Bulbert, Macquarie University

Funded by

Rio Tinto

Description

Invertebrate populations are dynamic and non-equilibrial, especially in climatically variable regions such as the Pilbara. We conducted a series of 15 surveys between 2004 and 2006 to quantify this spatial and temporal variability in terrestrial arthropods.

We found that the abundance and species richness of invertebrates peaked in November-January, before the start of the monsoonal rains. There were large seasonal and inter-annual variations in populations, and this hindered the ability of any taxonomic group to act as a surrogate for others. While grazing is often perceived to have a negative impact on biodiversity, we found that there was actually higher biodiversity near the man-made waterholes in grazed areas. As water is limited in arid areas, it is possible that the positive effect of waterholes outweighs the negative effect of grazing.

Different taxa had different distributional patterns, but there were a number of similarities that emerged. There were distinct communities in coastal, inland and high-elevation locations, although different taxa appeared to respond to different environmental factors.

Last Updated: 9 July 2009

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