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Eucalyptus obliqua wet forest with a wet sclerophyll understorey dominated by tea-tree, cutting-grass and bauera (G-type) |
Image: Mark Neyland |
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Eucalptus obliqua mixed forest with an understorey of rainforest species typical of thamnic rainforest, particularly horizontal scrub (T-type). |
Image: Mark Neyland |
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Eucalyptus obliqua mixed forest with an understorey of rainforest species typical of callidendrous rainforest (C-type). |
Image: Mark Neyland |
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Project summary:
This study is the vascular plant component of the silvicultural systems trial (SST), which is investigating alternative silvicultural systems for the management of wet eucalypt forests for wood production.
The three major vegetation types are: Eucalyptus obliqua wet forest with a wet sclerophyll understorey dominated by tea-tree, cutting-grass and bauera (G-type); E.obliqua mixed forest with an understorey of rainforest species typical of thamnic rainforest, particularly horizontal scrub (T-type); and E.obliqua mixed forest with an understorey of rainforest species typical of callidendrous rainforest (C-type). The three types are floristically distinct and readily recognisable in the field. Access tracks have been cut throughout the SST, between and around coupes, and quadrats were established along these tracks at a density of about one per hectare.
The ordination of internal and remote (external) control plots established before harvesting agrees with an ordination of vegetation data from plots surveyed many years prior to the establishment of the silvicultural systems trial. Therefore, monitoring of these plots is useful for comparison following harvesting. The data arising from these samples are used to develop ecological indicators for assessing management impacts. Fire history is the only sample variable found to be significantly related to the ordination.
Monitoring the floristics is useful for comparing the different silvicultural systems which include various retained patches of forest either as understorey islands, retained belts or aggregates.
Methodology: In this trial involving vascular plants plots of 10×10 m quadrats were established at a density of about one per hectare in each coupe within the SST. Plots of 50×20 m were also established in each coupe and divided into ten, 10×10 m quadrats.
The same design was used for control plots established in each of the three major vegetation types found in and around the trial area.
A total of 302 quadrats has been established. In each quadrat, data have been collected on the cover-abundance of each higher plant species present using the Braun-Blanquet scale, and the projected foliage cover (%) of each layer of the vegetation. The relative abundance and preferred substrate of a group of distinctive bryophytes has also been recorded. Environmental data have been collected on the slope, aspect, landform and rockiness. Fire history and soil drainage have been determined indirectly from other studies. The plot data have been subjected to ordination and indicator species analysis.
Datasets: None available.
Publications: Forestry Tasmania (2009). A new silviculture for Tasmania’s public forests: a review of the variable retention program. Forestry Tasmania, Hobart.
Neyland, M.G. (2001). Vegetation of the Warra silvicultural systems trial. Tasforests 13: 183-192.
Neyland, M. (2008). Floristic and structural responses of understorey islands, three years after harvesting, in wet Eucalyptus obliqua forests in Tasmania, Australia.
Neyland, M.N. (2010). The response of the vegetation to a range of alternatives to clearfelling of tall wet eucalypt forests at the Warra silvicultural systems trial, Tasmania, Australia. Doctoral thesis, University of Tasmania, Hobart.
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