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Ecology of the endangered Southern Shepherd's Purse Ballantinia antipoda (Brassicaceae) and the associated moss mat community on Mount Alexander, Victoria

Macroinvertebrate communities in Phragmites australis (Cav.) Trin. ex Steud. reed beds and open bank habitats in central Victorian streams in Australia

  • Authors: Jayawardana, Chandamali , Westbrooke, Martin , Wilson, Michael , Hurst, Cameron
  • Date: 2006
  • Type: Text , Journal article
  • Relation: Hydrobiologia Vol. 568, no. 1 (2006), p. 169-185
  • Full Text: false
  • Reviewed:
  • Description: Reed invasion is a common phenomenon of open streams with disturbed riparian vegetation in river catchments. Knowledge of the effects of such vegetation change on aquatic communities is fundamental to river management. Macroinvertebrate fauna in Phragmites australis (Cav.) Trin. ex Steud. and open bank habitats were examined in three rivers in central Victoria in order to understand the effect of such littoral habitat on macroinvertebrates. Data were analysed using Partially Nested Factorial ANOVA with season, river and habitats as main effects. Habitat structure had a significant effect (p < 0.05) on macroinvertebrate species richness, however this was not seasonally consistent across the three rivers. There was a significant increase (p < 0.05) in macroinvertebrate taxa richness in Phragmites habitats during winter and spring seasons. Total abundance of taxa showed no consistent significant differences in the two habitats. Results of Canonical Analysis of Principle Coordinates indicated significant differences (p < 0.05) in macroinvertebrate assemblages between Phragmites and bare bank habitats in all seasons. Habitat selection by taxa could be related to the microphysical environment of the habitats. This study suggests that reed beds create important littoral habitat structures which support diverse macroinvertebrate assemblages. © Springer 2006.
  • Description: C1
  • Description: 2003001589

Macroinvertebrate communities in willow (Salix spp.) and reed beds (Phragmites australis) in central Victorian streams in Australia

  • Authors: Jayawardana, Chandamali , Westbrooke, Martin , Wilson, Michael , Hurst, Cameron
  • Date: 2006
  • Type: Text , Journal article
  • Relation: Marine and Freshwater Research Vol. 57, no. 4 (2006), p. 429-439
  • Full Text: false
  • Reviewed:
  • Description: Exotic willows (Salix spp.) are widespread riparian tree species of rivers in temperate Australia and New Zealand. Despite being considered as a weed of national significance, little is known about the habitat value of willows and the impact on aquatic biota of vegetation change following willow management programmes. Macroinvertebrate fauna in root habitats of willows and Phragmites australis habitats were examined in three central Victorian rivers to understand the effect of such littoral habitat changes on macroinvertebrates. Data were analysed using Partially Nested Factorial ANOVA with season, river and habitat as main effects. Habitat structure had a significant effect (P < 0.05) on macroinvertebrate community assemblage. However, effect of habitat was not consistent among seasons. The greatest community differences among habitats were observed during winter and least separation during autumn. Taxa responsible for community differences among habitats were also identified. Species richness and abundance did not show consistent variation among habitats over different rivers or seasons. This study provided some indication of the macroinvertebrate community changes that would take place in situations where riparian vegetation changes takes place from willows to P. australis. © CSIRO 2006.
  • Description: C1
  • Description: 2003001620

Leaf litter decomposition and utilisation by macroinvertebrates in a central Victorian River in Australia

  • Authors: Jmck, Jayawardana , Westbrooke, Martin , Wilson, Michael
  • Date: 2010
  • Type: Text , Journal article
  • Relation: Victorian Naturalist Vol. 127, no. 4 (2010), p. 104-114
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  • Description: This study suggested that long-term persistence of willow roots can provide a positive effect on aquatic communities until the new native vegetation cover establishes. Leaf type has no significant influence over taxa richness; however their availability and persistence in the system has a significant effect on macroinvertebrate abundance in these streams. A combination of Phragmites reeds with Leptospermum and CalUstemon shrubs in revegetation programs will ensure a persistent supply of leaf litter to macroinvertebrate communities in these streams thus should be retained until native canopy cover eg. Eucalyptus spp. is re-established.

Habitat use and movement of river blackfish (Gadopsis marmoratus R.) in a highly modified Victorian stream, Australia

  • Authors: Khan, Minal , Khan, Tariq , Wilson, Michael
  • Date: 2004
  • Type: Text , Journal article
  • Relation: Ecology of Freshwater Fish Vol. 13, no. 4 (2004), p. 285-293
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  • Description: Movement and habitat use of river blackfish (Gadopsis marmoratus R.) was studied in a highly modified central Victorian stream (Birch Creek), Australia, using radio telemetry (N = 10) and mark-recapture (N = 113) between October 2001 to May 2002, and November to December 2002 respectively. Blackfish had a small home range of 10-26 m with strong affinity to a pool. However, small movements within a pool were common which resulted in relatively large cumulative movements. At a diel scale there were no significant differences in blackfish movement between day and night (Kruskal-Wallis test, P = 0.95). Six of seven blackfish translocated 40 m upstream or downstream of their original positions returned within 48 h, suggesting strong affinity not only to a pool, but also to a small region within a pool. Blackfish utilised slow flowing (0-20 cm. s-1) and deep waters (40-60 cm). Blackfish were strongly associated with the instream cover habitats of undercut banks and boulders. Significant differences were recorded in instream cover and water velocity used by blackfish between day and night (Kruskal-Wallis test, P = <0.01). At night blackfish used open areas with high water velocities whereas during the day blackfish used complex undercut banks with low water velocities. © Blackwell Munksgaard, 2004.
  • Description: C1
  • Description: 2003000779

Evidence for invasive carp mediated trophic cascade in shallow lakes of western Victoria, Australia

  • Authors: Khan, Tariq , Wilson, Michael , Khan, Minal
  • Date: 2003
  • Type: Text , Journal article
  • Relation: Hydrobiologia Vol. 506-509, no. (2003), p. 465-472
  • Full Text: false
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  • Description: Lakes of western Victoria are typically shallow (2-3 m), slightly saline (3-8 ppt) and eutrophic (total phosphorus 0.1-5 mg l-1 and total nitrogen 3-8 mg l-1). These lakes are prone to algal blooms in late spring and summer. We conducted experiments in ponds to determine whether lake zooplankton exert enough grazing pressure to control algal blooms and also if carp predation can regulate zooplankton communities and increase algal biomass. Zooplankton grazing (high zooplankton, low zooplankton and control) and carp predation (carp, nutrient and control) experiments had three treatments and each treatment had three replicates. Algal numbers and biomass (28
  • Description: C1
  • Description: 2003000543

Organic matter dynamics in willow and eucalypt lined central Victorian streams

  • Authors: Wilson, Michael
  • Date: 2001
  • Type: Text , Thesis , PhD
  • Full Text:
  • Description: The spread of exotic willows (Salix spp.) in SE Australia, New Zealand and South Africa has provoked widespread debate in scientific, management and broader communities. In Australia, the extent of spread is unknown, but at least 30000 km of river frontage in Victoria are lined by willows. Management and research literature has identified the poor knowledge of willow impacts on Southern Hemisphere aquatic ecosystems. It has been speculated that the major distinction between deciduous willows and evergreen native vegetation will be the timing and quality of litterfall. This would have flow-on consequences for metabolic processes, stream biota and water quality at reach, stream and catchment scales. These two vegetation types were studied through the preparation of partial organic matter budgets for native and willow lined reaches in a central Victorian catchment. Organic matter inputs from litter, groundwater and gross primary production (GPP), organic matter standing crop . and respiratory output were quantified. Total inputs to willow and native reaches were similar (735 and 764 g ash free dry weight m•' yl, respectively). Inputs were dominated by litterfall (-60%) and there were no significant differences in annual litterfall between sites. GPP contributed -20% of total inputs and estimates suggested there were few significant differences in annual GPP, 24 h community respiration, ratio of GPP to community respiration (PIR) or net daily metabolism (NDM) between sites. Groundwater contributed -20% of total inputs with one third of the dissolved organic matter sourced during short flow paths through riparian sediments. Aggradation at willow sites appeared to increase the riparian flow path. Willow and native sites were heterotrophic and similarly dependent on allochthonous organic matter (P/R=O.2, NDM= -.6, and ratio of net primary production to total inputs -0.1). Willow research and management should also focus on retention capacity, including the recruitment and role of LWD and the structure and function of root systems. Removal of willows potentially facilitates native vegetation establishment but simultaneously decreases retention capacity and metabolic control by the canopy. Establishing native vegetation to fulfil broader biodiversity objectives whilst retaining willows for their potentially positive roles is a management challenge. In principle, establishing native species on the upland-sides of fringing willows and under willow canopies will direct succession toward a preferred outcome without destructive disturbance. Understanding of when benefits of willows outweigh their costs is a notable gap.
  • Description: School of Science & Engineering
  • Description: The spread of exotic willows (Salix spp.) in SE Australia, New Zealand and South Africa has provoked widespread debate in scientific, management and broader communities. In Australia, the extent of spread is unknown, but at least 30000 km of river frontage in Victoria are lined by willows. Management and research literature has identified the poor knowledge of willow impacts on Southern Hemisphere aquatic ecosystems. It has been speculated that the major distinction between deciduous willows and evergreen native vegetation will be the timing and quality of litterfall. This would have flow-on consequences for metabolic processes, stream biota and water quality at reach, stream and catchment scales. These two vegetation types were studied through the preparation of partial organic matter budgets for native and willow lined reaches in a central Victorian catchment. Organic matter inputs from litter, groundwater and gross primary production (GPP), organic matter standing crop . and respiratory output were quantified. Total inputs to willow and native reaches were similar (735 and 764 g ash free dry weight m•' yl, respectively). Inputs were dominated by litterfall (-60%) and there were no significant differences in annual litterfall between sites. GPP contributed -20% of total inputs and estimates suggested there were few significant differences in annual GPP, 24 h community respiration, ratio of GPP to community respiration (PIR) or net daily metabolism (NDM) between sites. Groundwater contributed -20% of total inputs with one third of the dissolved organic matter sourced during short flow paths through riparian sediments. Aggradation at willow sites appeared to increase the riparian flow path. Willow and native sites were heterotrophic and similarly dependent on allochthonous organic matter (P/R=O.2, NDM= -\.6, and ratio of net primary production to total inputs -0.1). Willow research and management should also focus on retention capacity, including the recruitment and role of LWD and the structure and function of root systems. Removal of willows potentially facilitates native vegetation establishment but simultaneously decreases retention capacity and metabolic control by the canopy. Establishing native vegetation to fulfil broader biodiversity objectives whilst retaining willows for their potentially positive roles is a management challenge. In principle, establishing native species on the upland-sides of fringing willows and under willow canopies will direct succession toward a preferred outcome without destructive disturbance. Understanding of when benefits of willows outweigh their costs is a notable gap.
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