146 resultados para cover-zone

em Deakin Research Online - Australia


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This study describes the use of landscape transition analysis as a means for effective basin management. Land cover transitions from 1995 to 2002 were analyzed using a cross-tabulation matrix for an important economic zone in south-west Victoria, Australia. Specifically, the matrix was used to determine whether the transitions were random or systematic. Random landscape transitions occur when a land cover replaces other land covers in proportion to their availability. Systematic landscape transitions occur when there are deviations from random patterns, and land use types ‘target’ other land use types for replacement. The analysis was conducted with 11 land cover categories and showed that dryland pastures have been systematically losing area to dryland crops and blue gum (Eucalyptus globulus) plantations. Dryland crops have systematically expanded in the north-east of the catchment, an area where increasing in-stream salinization has occurred concurrently with this transition. The systematic expansion of the blue gum plantations has been predominantly in the south-west of the catchment and has the potential to reduce stream flows and groundwater recharge in an already water-stressed region, as blue gums use more water than the dryland pastures they are replacing. All other transitions were largely random. These findings have implications for land use planning in the study area for regional water balance and revegetation strategies. Landscape transition analysis is a cost-effective means of contributing to the management of water resources at a regional scale, and is highly recommended for future basin planning.

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A localised aggregation of blue whales. which may be pygmy blue whales (B. m. brevicauda), occurs in southern Australian coastal waters (between I39°45'E-143°E) during summer and autumn (December-May), where they feed on coastal krill (Nyctiphanes australis). a species which often forms surface swarms. While the abundance of blue whales using this area is unknown, up to 32 blue whales have been sighted in individual aerial  surveys. Krill appear to aggregate in response to enhanced productivity  resulting from the summer-autumn wind-forced Bonney Coast upwelling along the continental shelf. During the upwelling's quiescent (winter-spring) period. blue whales appear to be absent from the region. Krill surface  swarms have been associated with 48% of 261 blue whale sightings since 1998, with direct evidence of feeding observed in 36% of all sightings. Mean blue whale group size was 1.55 (SD =0.839), with all size classes represented including calves. This seasonally predictable upwelling system is evidently a regular feeding ground for blue whales, and careful  management of human activities is required there.

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A brachiopod fauna of 16 species belonging to 11 genera and three genera and species indeterminate from the middle and upper parts of the Juripu Formation in the Yarlung-Zangbo (Indus-Tsangbo) Suture zone (=Yarlung-Zangbo River zone), southern Tibet, is described and figured for the first time. A new species, Taeniothaerus zhongbaensis, is described. The fauna is comparable with that in the Kalabagh Member of the Wargal Formation of the Salt Range, Pakistan, and is considered to be most likely Capitanian (late Guadalupian/Middle Permian) to Wuchiapingian (early Lopingian/early Late Permian) in age, as indicated by the majority of the brachiopod species and by being constrained by an underlying fusulinacean fauna (Parafusulina Zone) and an overlying ammonite fauna (Cyclolobus fauna).

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There are currently no performance indicators in place for assessing the successful implementation of Victoria,'s strategic plans (Coastal Action Plans, CAPs) in achieving Integrated Coastal Zone Management (ICZM) at a regional level. This article explores the findings of a study which assessed the success of the approach adopted in Victoria under the State Coastal Management Act 1995 to implement ICZM through CAPs. The study developed a set of criteria for measuring this success. We conclude with a discussion of how appropriate such an approach may be in other jurisdictions.

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In 1953 the Heard and McDonald Islands Act, which formalised the transfer of sovereignty over the two named sub-Antarctic islands from the United Kingdom, was passed by the Australian Government. For the ensuing 40 years, Australian management of the Islands was uneventful. The first subAntarctic scientific station was established at Atlas Cove, on Heard Island, in December 1947 following the initial indication by Britain of a willingness to transfer rights to the Islands. In 1987 the Islands, together with their 12 mile territorial sea, were proclaimed a wilderness reserve with a number of activities including fishing and mining prohibited. The same area was included on the WorId Heritage List in 1997. In 1979 a 200 nautical mile Australian Fishing Zone (AFZ) was proclaimed around all Australian territories. In 1994 new terminology was embraced and the Exclusive Economic Zone was declared.

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Four different tool steel materials, P20, H13, M2 and D2, were nitrocarburised at 570°C in a fluidised bed furnace. The reactive diffusion of nitrogen and carbon into the various substrate microstructures is compared and related to the different alloy carbide distributions. The effect of carbon bearing gas (carbon dioxide, natural gas) on carbon absorption is reported, as well as its influence on compound layer growth and porosity. Partial reduction of Fe3O4 at the surface resulted in the formation of a complex, epsi-nitride containing oxide layer. In H13, carbon was deeply absorbed throughout the entire diffusion zone, affecting the growth of grain boundary cementite, nitrogen diffusivity and the sharpness of the compound layer: diffusion zone interface. When natural gas was used, carbon became highly concentrated in the compound layer, while surface decarburisation occurred with carbon dioxide. These microstructural effects are discussed in relation to hardness profiles, and compound layer hardness and ductility. The surfaces were characterised using glow discharge optical emission spectroscopy, optical and scanning electron microscopy and X-ray diffraction.

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The diets of four highly-abundant, dominant fish species within the Surrey River, a small intermittently open estuary in south-east Australia, were examined from specimens collected between July 2004 and June 2005. These four, similar-sized species (Atherinosoma microstoma, Galaxias maculatus, Philypnodon grandiceps and Pseudogobius olorum) have limited ability to spatially segregate along the length of the estuary owing to its small size relative to other estuarine habitats. All four species fed on a variety of prey items including crustaceans, insects and detritus. Despite this parity, the four species were demonstrated to occupy differing dietary niches that were concluded to be responsible for reducing interspecific feeding competition. Seasonal variations in the diets were observed for A. microstoma and Philypnodon grandiceps, with these species also exhibiting contrasting diel feeding behaviours. The closure of the estuary mouth led to the flooding of its margins, resulting in an increase in the size of the estuary and providing alternative food resources for the fish to exploit. It appears the inundation of the flood-zone facilitated further significant divergence in the diets of the fish and is likely to be of high ecological value to the estuary.

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A brachiopod fauna including 19 species of 17 genera from an exotic block in the Indus–Tsangpo suture zone in southern Tibet is described and illustrated. The brachiopod fauna is dominated by Martinia elegans and two new taxa: Jinomarginifera lhazeensis gen. et sp. nov. and Zhejiangospirifer giganteus sp. nov. The fauna is closely comparable with those from the middle and upper parts of the Wargal Formation and the Chhidru Formation in the Salt Range of Pakistan, the Chitichun Limestone in southern Tibet, and the Basleo area of West Timor, and these correlations suggest a Wuchiapingian age. The fauna exhibits substantial links with both peri–Gondwanan and Cathaysian faunas, which may imply that it is a seamount biota originally located in the southern margin of the Neotethys during the Late Permian, and was later (in the early Cenozoic) displaced and became sandwiched into younger marine deposits in the collision process between India and Eurasia.

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Fusulinoideans from the Metadoliolina dutkevitchi-Monodiexodina sutchanica Zone of the lower part of the Chandalaz Formation in the Senkina Shapka section in South Primorye, Far East Russia, are described. The fusulinoidean zone is assigned to the early Midian (=Capitanian: late Middle Permian) based mainly on the morphologie and biostratigraphic characteristics of Metadoliolina dutkevitchi. Previously, a Midian age has been established for the Metadoliolina dutkevitchi-Monodiexodina sutchanica Zone by the coexistence of Lepidolina species. However, the occurrence of Lepidolina with the two zonal species in this area has not been verified by the illustration of Lepidolina specimens. We examined a fusulinoidean-bearing sample from the Metadoliolina dutkevitchi-Monodiexodina sutchanica Zone, and three fusulinoidean species, Monodiexodina sutchanica, Pseudofusulina sp. and Metadoliolina dutkevitchi, are de-scribed and illustrated.

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This article explores some aspects of the role of race and gender in shaping women postgraduate students' experience of intercultural study. It focuses on various social and cultural aspects of their sojourn. These were suggested by data from two small pilot research projects investigating the experiences of two cohorts of international women postgraduate students, the one studying in an Australian university and the other, a Canadian. The authors focus particularly on the intersections between the students' representation of themselves as women and the way they see themselves represented by their host cultures. In other words, they are interested in the students' understandings of themselves as 'other', and how this impacts on their representations of 'self'. The authors suggest that these representations reflect a process of negotiation of identity that occurs in what they call the globalising university 'contact zone'. The concept of contact zones derives from post-colonial theory. A further goal of this article, then, is to examine how such data appear when viewed from a post-colonial perspective.