An investigation of the soil seedbank and seed germination of perennial species in Belah (Casuarina pauper)woodlands in north-west Victoria
- Authors: Callister, Kate , Florentine, Singarayer , Westbrooke, Martin
- Date: 2018
- Type: Text , Journal article
- Relation: Australian Journal of Botany Vol. 66, no. 3 (2018), p. 202-212
- Full Text: false
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- Description: Semiarid and arid woodlands across much of southern Australia have been subject to prolonged high total grazing pressure leading to loss of species diversity and a lack of recruitment of long-lived perennial species. Regeneration of perennial species requires grazing pressure to be maintained at low levels, but gaps remain in our ecological understanding of regeneration potential. The present study investigated the abundance of germinable seed in the soil seedbank in high quality remnants of Casuarina pauper F.Muell. ex L.A.S.Johnson (Belah) woodlands in north-west Victoria. Seed viability and response to six seed pretreatments including dry heat, wet heat, smoky water, soaking in distilled water, cold stratification and sand scarification were also tested to determine whether seed factors may be limiting regeneration. Results suggest that seed viability was not a limiting regeneration factor for nine out of the 10 perennial species tested with the exception of Alectryon oleifolius S.T. Reynolds. Only small amounts of seed from perennial species, largely Chenopodiaceae species and C. pauper, were found in the soil seedbanks of intact sites, suggesting component perennial species do not maintain long-term soil seedbanks. Results suggest that natural recovery of perennial species diversity in depauperate sites will depend on seed dispersal.
Differences in composition and vertical distribution of Collembola from canopies of three Australian rainforests
- Authors: Greenslade, Penelope , Sutrisno , Florentine, Singarayer
- Date: 2016
- Type: Text , Journal article
- Relation: Soil Organisms Vol. 88, no. 3 (2016), p. 175-192
- Full Text: false
- Reviewed:
- Description: Invertebrates from three rainforest canopies (tropical TRF, subtropical STR and cool temperate CTR) were sampled by insecticidal knockdown in order to compare biodiversity of canopy faunas in Australia; lower and higher TRF and STR were sampled separately. Numerous Collembola were collected, mainly in the family Entomobryidae but relative family abundance of taxa differed between forest types. TRF was characterised by Dicyrtomidae, STR by Entomobryidae and CTR by Isotomidae and Neanuridae. Also morphospecies abundances differed between forest types. The high canopy of TRF was dominated by Lepidocyrtoides sp. 3 while the low canopy was dominated by Lepidocyrtoides sp. 6. SRF had a high proportion (80% of individuals) of a single species, the canopy specialist, Epimetrura rostrata, in both high and low canopies. In CTR, the dominant species was Entomobrya sp. cf. varia. Significant differences were found in either or both abundance and species composition of Collembola between trees within each rainforest. A significant difference was found in species abundances between lower and upper canopies in TRF and STR but not in species composition, also between canopies, pitfall samples and soil/leaf litter faunas. High levels of apparent rarity were found in all the three rainforests, being most marked on STR. Only four species occurred in all three types of rainforest indicating that beta diversity (i.e. species turnover between the three sites) was high. Our results are the first to compare faunal composition between three rainforest types and have implications for management of forests under a climate change scenario.
Decade-long response of arid-land mallee vegetation to fire, flooding and grazing in south-eastern Australia
- Authors: Florentine, Singarayer , Milberg, Per , Di Stefano, Julian , Westbrooke, Martin , Graz, Patrick
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Arid Environments Vol. 121, no. October (2015), p. 7-14
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- Description: Australian arid vegetation has evolved within highly variable environments characterised by low rainfall and sporadic fire events. Episodic high rainfall events are a significant factor in plant species recruitment, but their unpredictability makes them difficult to study. We report on the response of vascular plants to a major rainfall event and flood in an arid region of south-eastern Australia. Fire that occurred two months before the flood was incorporated into the study. Paired fenced and unfenced plots were established at control locations and also in areas that had been either flooded, burnt, or flooded and burnt. Objectives were to quantify the long-term effects of fire, flood and vertebrate herbivory, and their interactions, on vegetation composition, plant life forms and species diversity. We found that relative to controls (i) there was a significant effect of flooding on vegetation composition, (ii) changes in life form abundance were driven by flooding and grazing, (iii) there was a strong positive relationship between grazer exclusion and species diversity that was maintained over time and (iv) there was little effect of fire. Understanding the long-term effects of both natural disturbances and vertebrate herbivory will benefit plant conservation in the arid zone. © 2015 Elsevier Ltd.
The aerial invertebrate fauna of subantarctic Macquarie Island
- Authors: Hawes, Timothy , Greenslade, Penelope
- Date: 2013
- Type: Text , Journal article
- Relation: Journal of Biogeography Vol. 40, no. 8 (2013), p. 1501-1511
- Full Text: false
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- Description: Aim: The extent and diversity of invertebrate aerial dispersal both on remote islands and in polar regions has long been of interest to biogeographers. We therefore monitored the airborne dispersal of insects and other micro- and macroinvertebrates to and on Macquarie Island in order to assess (1) the magnitude and composition of local aerial dispersal activity by the island's invertebrate fauna, and (2) the potential for exotic arrival and establishment. Location: Macquarie Island. Methods: Two robust wind-traps were run year-round on Macquarie Island from 1991 to 1994 to collect airborne insects and other micro- and macroinvertebrates. Results: More than 3000 invertebrates were caught in these traps over the sampling period in the most comprehensive aerial survey of subantarctic invertebrates to date. Representatives of seven orders of Insecta were captured: Psocoptera, Thysanoptera, Hemiptera, Coleoptera, Diptera, Lepidoptera and Hymenoptera. Other taxa captured included other arthropods (Arachnida and Collembola) but also terrestrial Gastropoda. Evidence of possible long-distance dispersal (LDD) was limited to two exotic catches (one species of Collembolon, and one species of Thysanoptera). The abundance and composition of indigenous invertebrates caught in the traps indicates that the frequency of short-distance dispersal (SDD) movements on the island far exceeds that which had previously been realized. Main conclusions: More than half the total catch (53%) was of flightless (i.e. passively dispersed) invertebrates, with 84% of them flightless in one of the two traps. The extent of passive dispersal movements is consistent, with most invertebrates being widely distributed at a whole-island scale. Aerial dispersal may act as a conduit for non-indigenous arrivals but this occurs infrequently. Other explanations for exotic species in traps are equally likely. The implications of these findings are discussed in relation to terrestrial invertebrate biogeography. © 2013 Blackwell Publishing Ltd.
- Description: 2003011217
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.
When more is less : Urban remnants support high bird abundance but diversity varies
- Authors: Fitzsimons, James , Antos, Mark , Palmer, Grant
- Date: 2011
- Type: Text , Journal article
- Relation: Pacific Conservation Biology Vol. 17, no. 1 (2011), p. 97-109
- Full Text: false
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- Description: Urban remnant vegetation, especially where it occurs in public parks, allows for relatively easy access for ongoing biodiversity monitoring. However, relatively little baseline information on bird species distribution and abundance across a range of identifiable urban remnants appears in the published literature. We surveyed the relative abundance and distribution of birds across urban and suburban remnant vegetation in Melbourne, Australia. One hundred and six species were recorded, of which 98 were indigenous. Red wattlebirds had the highest mean relative abundance with 2.94 birds/ha, followed by rainbow lorikeets (2.51), noisy miners (1.93), brown thornbills (1.75) and spotted doves (0.96). There was no obvious trend between overall relative abundance and the size of the remnant, in contrast to species richness which was positively correlated with remnant size. The data revealed that some species were either totally restricted to, or more abundant in, larger remnants and generally absent from smaller remnants. Some of the more common birds (crimson rosella, superb fairy-wren, spotted pardalote and black-faced cuckoo-shrike) recorded during this study were detected at similar densities to those found in comparable vegetation to the east of Melbourne within a largely forested landscape. Other species occurred at much lower densities (e.g., white-browed scrubwren, brown thornbill, eastern yellow robin and grey fantail) or had habitat requirements or ecological characteristics that could place them at risk of further decline or local extinction in the urban area. We identify a suite of bird species of potential conservation concern within Melbourne's urban landscape. The establishment of repeatable, fixed-point, and long-term monitoring sites will allow for repeat surveying over time and provide an early warning of population declines, or conversely an indication of population increase for other species.
Biological toxicity of lanthanide elements on algae
- Authors: Tai, Pei Dong , Zhao, Qing , Su, Dan , Li, Peijun , Stagnitti, Frank
- Date: 2010
- Type: Text , Journal article
- Relation: Chemosphere Vol. 80, no. 9 (2010), p. 1031-1035
- Full Text: false
- Reviewed:
- Description: The biological toxicity of lanthanides on marine monocellular algae was investigated. The specific objective of this research was to establish the relationship between the abundance in the seawater of lanthanides and their biological toxicities on marine monocellular algae. The results showed that all single lanthanides had similar toxic effects on Skeletonema costatum. High concentrations of lanthanides (29.04 ± 0.61
Cladoceran-inferred environmental change during the LGM to Holocene transition from Onepoto maar paleolake, Auckland, New Zealand
- Authors: Kattel, Giri , Augustinus, Paul
- Date: 2010
- Type: Text , Journal article
- Relation: New Zealand Journal of Geology and Geophysics Vol. 53, no. 1 (2010), p. 31-42
- Full Text: false
- Reviewed:
- Description: Subfossil cladocerans have rarely been used for paleoenvironmental reconstruction from New Zealand lake sediments, and here we detail the first examination of the response of cladocerans to past environments from an Auckland maar paleolake. Cladoceran remains were examined in the upper 230 cm of the lacustrine sediments spanning c. 9-31 cal. ka BP from Onepoto maar during which time the lake underwent significant changes. Lake level was relatively high during the Last Glacial Coldest Period (c. 28-18 cal. ka BP), with limited forest in the catchment, shoreline vegetation and low water temperature indicated by the presence of a planktonic taxon, Bosmina meridionalis, and a cold tolerant chydorid cladoceran Alona sp. (affinis type). However, the climate during the last glacial termination after c. 17.9 cal. ka BP changed abruptly, perhaps becoming extremely dry and windy, resulting in increased production of cladoceran resting eggs. Between c. 17.6 and 14.1 cal. ka BP, a gradually ameliorating climate with sustained windiness and dryness might have been unfavourable for hatching of chydorid cladoceran eggs and their recolonisation. After c. 14.1 cal. ka BP, continued climatic amelioration was accompanied by reduced lake levels inferred from high cladoceran littoral: planktonic ratios as well as increased cladoceran diversity and abundance of less cold tolerant chydorid taxa: Alona guttata, Alona sp. (intermedia type) and Alonella excisa. At c. 9 cal. ka BP, the maar crater rim was breached by the marine waters commensurate with postglacial sea-level rise, resulting in degraded water quality and production of a large number of cladoceran ephippia in the sediments. © 2010 The Royal Society of New Zealand.