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Aporodrillus warrai - one of the two deep-burrowing earthworm species identified as new to science during this project. |
Image: Bill Brown |
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Project summary:
This project:
Investigated relationships between vegetation, soil physical, chemical, and biological properties and earthworms at three wet eucalypt forest sites: Warra (LTER) Silvicultural Systems Trial (Tasmania), Tanjil Bren State Forest (Victoria), and Bago/Maragle State Forest (NSW).
Helped to clarify the immediate and short- to mid-term impact of forest management on earthworms, with particular reference to the interpretation of clearfelling, burning and soil disturbance on earthworms and other soil biological and chemical parameters.
From pre-treatment sampling:
- Five native earthworm species are common to all three treatment coupes: two are surface dwelling earthworms, generally located at depths of 0 to 15 cm in the soil profile. The remaining three species including Aporodrilus warrai (Sp. nov.) (Blakemore 2000), Megascolides tener (Sp. nov.) (Blakemore 2000), are deep burrowing earthworms commonly found at depths of 15 to 30 cm and 30 to 45 cm, respectively. Cocoons of these deep burrowing species are also commonly found at depths of 30 to 45 cm.
- Earthworm species diversity, abundance and biomass per hectare of uncut forest, are greatest in WR001B coupe, followed by WR008B and WR008C coupe(s).
- Statistical analysis of transformed earthworm and soil microbial biomass data suggest:
- Pre- treatment earthworm sampling shows strong temporal and functional variation of earthworms within the forest soil profile (p<0.05).
- For the three treatment coupes, earthworm biomass (measured as fresh weight of earthworm tissue), abundance and species richness decreases significantly with increasing depth (p<0.05).
For the three treatment coupes, mature earthworms are commonly located in all three soil layers (0 to 45 cm in depth), with immature earthworms located in the top two soil layers (0 to 15 and 15 to 30 cm in depth). Presence of immature earthworms is strongly correlated with presence of mature earthworms, suggesting that young earthworms are commonly situated with their older counterparts (p<0.05).
For the three treatment coupes, soil microbial nitrogen is concentrated in the top 30 cm of soil profiles (p<0.05) with high soil moisture decreasing soil microbial nitrogen (p<0.05).
Methodology: Relationships were investigated between vegetation, soil physical, chemical, and biological properties and earthworms at the three wet eucalypt forest sites. Earthworms were collected from forest stands before and after clearcut and gap harvesting. Species, abundance, biomass and functional diversity of earthworms were determined via qualitative and quantitative sampling regime(s).
At Warra, pre- and post- treatment earthworm sampling was completed in WR001B, WR008B and WR008C coupes. Soil samples have been collected and soil microbial biomass determined for all three coupes. Pre and post- treatment soil cores have been collected for bulk density determinations.
Datasets: None available.
Publications: Blakemore, R.J. (2000). Tasmanian Earthworms on CD-ROM VermEcology, PO BOX 414, Kippax ACT 2615, Kippax ACT.
Blakemore, R.J. (2000). The taxonomic status of the earthworm fauna of Lake Pedder, Tasmanian Wilderness World Heritage Area – with the description of three new genera and fourteen new species. Records of the Queen Victoria Museum 109.
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