Littoral macroinvertebrates in relation to native and exotic riparian vegetation in streams of central victoria, Australia
- Authors: Jayawardana, Chandamali
- Date: 2011
- Type: Text , Journal article
- Relation: International Journal of Energy, Environment and Economics Vol. 19, no. 6 (2011), p. 635-651
- Full Text: false
- Reviewed:
- Description: Exotic willows (Salix spp.) are widespread riparian tree species of rivers in temperate Australia and New Zealand. Willow removal is an integral part in riparian management of rivers in temperate Australia. Reeds (Phagmites australis) and shrubs (Leptospermum spp. and Callistemon spp.) are common vegetation in the riparian zone of Victorian streams and considered suitable for planting along channels in revegetation programmes following willow removal. Little is known about the novel habitats created by willows and the impact on aquatic biota of vegetation successional process following willow management programmes. Macroinvertebrate fauna in willow, Phragmites australis, Leptospermum/ Callistemon and bare bank habitats were examined in three central Victorian streams in Australia to understand the effect of such littoral habitats on macroinvertebrates taxa richness, abundance and community composition. Data were analysed using a two way ANOVA with habitat and season as main effects. Habitats had a significant effect (p<0.05) on macroinvertebrate taxa richness. Willow and Phragmites habitats generally contained more taxa and total number of individuals than Leptospermum/ Callistemon or bare bank habitats though the absolute rank order of habitats differed among seasons. In Phragmites habitats species richness was higher during winter and spring. In willow habitats it was higher during spring and autumn and in Leptospermum/ Callistemon habitats during summer. Multivariate analysis showed that community composition within the habitats was significantly different, with willow and Phragmites separating from Leptospermum/ Callistemon and bare bank habitats in seasons with high flow. It appears that a vegetation transition from willows to bare banks or shrubs alone would be potentially more disruptive to macroinvertebrate communities than a transition from willows to a combination of littoral reeds and native riparian vegetation. This result suggests that exploration of techniques to guide a transition from willow to native littoral and riparian vegetation without a disruptive clearing phase is therefore desirable. © 2011 Nova Science Publishers, Inc.
Potential effects of riparian vegetation changes on functional organisation of macroinvertebrates in central Victorian streams
- Authors: Jayawardana, Chandamali , Westbrooke, Martin
- Date: 2010
- Type: Text , Journal article
- Relation: Victorian Naturalist Vol. 127, no. 2 (2010), p. 36-46
- Full Text: false
- Reviewed:
- Description: Exotic willows (Salix spp.) are widespread riparian tree species of rivers in temperate Australia and New Zealand. Despite being a Weed of National Significance, little is known about the novel habitats created by willows and the impact on aquatic biota of vegetation change following willow management programs. Reeds (Phragmites australis) and shrubs (Leptospermum spp. znaCallistemon spp.) are common taxa in the riparian zone of Victorian streams and are considered suitable for planting along channels in revegetation programs following willow removal. Categorisation of macroinvertebrates into 'trophic' groups allows better understanding of the processes of energy flow, material cycle and stream ecosystem function. Macroinvertebrate functional feeding groups associated with willow, Phragmites australis, Leptospermum/CaUistemon and bare bank habitats were examined in three central Victorian streams to gain insights to potential effects of willow removal on functional organisation of macroinvertebrates. There was a significant effect of habitat on macroinvertebrate functional feeding groups except collectors. Notable differences in functional feeding groups included a greater abundance ofpredators and grazers in Phragmites habitats and a greater abundance of snredders in willow habitats; however, these changes were variable during different seasons. It appears riparian vegetation change associated with willow management could bring about change of functional organisation of macroinvertebrates in these streams. This suggests that the vegetation changes can bring about changes in material cycle and energy flow within these streams.