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Simon Watson and partner Susan Burns collecting log-dwelling invertebrates, February 2003. |
Image: Simon Grove |
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Prostomis atkinsoni, one of the saproxylic beetles studied by Simon Watson. |
Image: Simon Grove |
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Prostomis atkinsoni - graphite. |
Image: Melanie Evans |
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Project summary:
Prostomis atkinsoni is a saproxylic organism found in Tasmanian tall eucalypt forests. Saproxylics are a diverse and functionally important group, particularly in the breakdown of deadwood and nutrient cycling within forest ecosystems. Current forestry practices threaten the long-term viability of the dead wood habitat in southern Tasmanian forests. Fragmentation of forest through degradation of the dead wood habitat may result in population fragmentation of many saproxylic organisms, which could result in a breakdown of the nutrient cycle in the forest ecosystem.
This study assessed the dispersal ability of Prostomis atkinsoni. By attempting to determine population structure of saproxylic organisms we may be able to create a more sustainable system of forest management. Whilst most ecological methods used for measuring dispersal are unsuitable for small saproxylic organisms, molecular techniques can be used effectively to estimate dispersal ability and for gene flow estimates, which may be more important in terms of population stability.
By employing a biparentally inherited allozyme marker and a 611 base pair segment of the cytochrome c oxidase sub unit 1 gene in the maternally inherited mitochondrial genome, the project uncovers novel information about the dispersal ability and population genetic structure of the species. The genetic data show that while P. atkinsoni displays relatively panmictic long-term gene flow over a spatial scale of up to ten kilometres of old growth forest, it also exhibits transient accumulations of genetically-similar individuals at very fine scales. There are indications in the data that male-biased dispersal may occur. While there was no evidence of major restrictions to gene flow throughout continuous forest, it remains dificult to ascertain what would be the impact of different scales of habitat fragmentation on dispersal, particularly in the light of the evidence for male-biased dispersal and transient fine-scale genetic structure. The illustration here is part of a set commissioned by Forestry Tasmania from Melanie Evans. The other projects undertaken at Warra which include further illustrations by Melanie are: WRA045 Invertebrate succession in the Warra SST.WRA097 Dispersal ability of the beetle Coripera deplanata.WRA121 Biology and conservation ecology of saproxylic beetle species.WRA136 Illustrations of some of Warra’s insects.
Methodology: Various molecular techniques were used in order to assess dispersal ability:
Allozyme Electrophoresis
DNA extraction
DNA amplification
Single Stranded Conformation of Polymorphism (SSCP)
Sequencing
Microsatellite Screening
Exon Priming Intron Crossing (EPIC) markers
Datasets: None available.
Publications: Watson, S. (2003). Dispersal and gene flow in Prostomis atkinsoni (Coleoptera). Honours thesis, LaTrobe University, Melbourne.
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