Добірка наукової літератури з теми "Plant communities Victoria Nepean"

Connection to centralised regional sewage systems has been too expensive for small-dispersed communities, and these townships have traditionally been serviced by on-site septic tank systems. The conventional on-site system in Australia has consisted of an anaerobic holding tank followed by adsorption trenches. This technique relies heavily on the uptake of nutrients by plants for effective removal of nitrogen and phosphorus from the effluent, and is very seasonal in its efficiency. Hence, as these small communities have grown in size, the environmental effects of the septic tank discharges have become a problem. In locations throughout Australia, such as rural Victoria and along the Hawkesbury-Nepean River, septic tanks are being replaced with the transport of sewage to regional treatment plants. For some isolated communities, this can mean spending $20,000-$40,000/household, as opposed to more common connection prices of $7,000/household. This paper explores some alternative options that might be suitable for these small communities, and attempts to identify solutions that provide acceptable environmental outcomes at lower cost. The types of alternative systems that are assessed in the paper include local treatment systems, separate blackwater and greywater collection and treatment systems both with and without non-potable water recycling, a small township scale treatment plant compared to either existing septic tank systems or pumping to a remote regional treatment facility.The work demonstrated the benefits of a scenario analysis approach for the assessment of a range of alternative systems. It demonstrated that some of the alternatives systems can achieve better than 90% reductions in the discharge of nutrients to the environment at significantly lower cost than removing the wastewater to a remote regional treatment plant. These concepts allow wastewater to be retained within a community allowing for local reuse of treated effluent.

Driven by concerns centred on the potential impacts of new development on the Hawkesbury-Nepean River, the management of effluent from Sewage Treatment Plants is a growing issue for regulators, communities and Sydney Water Corporation. Conventional users of recycled water such as golf courses, parks and on-site uses are making way for more innovative and sustainable approaches. Rouse Hill Recycled Water Plant and the Picton Agricultural Reuse Schemes are two examples where Sydney Water has adopted a different approach to water recycling. With both schemes now in operation, demand for the product has surpassed expectations and has already begun to exceed current availability. Faced with the option of expanding the schemes in the near future, SWC is continuing to look for new ways of providing sustainable water services to the people of Sydney.

We used multivariate methods to investigate the composition and spatial organisation of tundra plant communities in the Wellington Bay region of southeastern Victoria Island (69°N, 106°W). Ordination and classification of sites at an intermediate scale (≈ 1 ha) were conducted using principal components analysis and sums of squares agglomerative clustering on a matrix of standardized chord distances. The findings suggested eight vegetation classes. These communities are described floristically. At this spatial scale, the vegetation showed correspondence to elevation, slope, and thickness of soil, but not to aspect. The spatial patterns of multiple plant species and physical variables (i.e., slope of terrain and thickness of soil) were examined using multiscale ordination and double logarithmic regressions of variance on distance, respectively. Multiscale ordination revealed ever-increasing plant heterogeneity with distance (0.25 – 1600 m) and suggested only weak general patterns at scales ≤ 200 m. Similarly, variance in the physical factors tended to increase continually with distance. Both the vegetation and physical environment thus appeared to be organised on gradients. Key words: Arctic, classification, ordination, spatial scale, tundra.

AbstractThis paper proposes a new objectively-generated vegetation classification for southern and northern Victoria Land (continental Antarctica) based on the floristic composition of the plant communities. The new classification aims to integrate the existing physiognomic classification of the cryptogamic Antarctic tundra, provide useful data on floristic composition and distribution of the vegetation occurring in southern and northern Victoria Land, and develop a suitable tool allowing easy comparison of syntaxa from different locations. Field data from 26 sites along a latitudinal gradient (72°–77°S) were analysed by a hierarchical classification integrated with multivariate statistics, including indirect ecological information (Principal Component Analysis). Similarity of the identified groups was assessed through the Jaccard similarity index. The new classification is compatible with previous ones and is widely applicable to Victoria Land and includes previous classification. This standardized approach relates plant communities to their floristic composition and provides a basis for relating vegetation composition to environmental gradients and to patterns of vegetation dynamics and succession which are still poorly understood in Antarctica.

AbstractThe Jurassic plant fossil record of Gondwana is generally meagre, which renders phytogeographic and palaeoclimatic interpretations difficult to date. Moreover, plant fossil assemblages mainly consist of impressions/compressions with rather limited palaeobiological and palaeoecological significance. We here present a detailed survey of new Early Jurassic plant assemblages from the Pliensbachian Shafer Peak Formation, north Victoria Land, Transantarctic Mountains. Some of the well-preserved fossils yield cuticle. The floras consist of isoetalean lycophytes, sphenophytes, several ferns, bennettitaleans, and conifers. In addition, three distinct kinds of conifer shoots and needles were obtained from bulk macerations. The composition of the plant communities is typical for Jurassic macrofloras of Gondwana, which underscores the general homogeneity of Southern Hemisphere vegetation during the mid-Mesozoic. Altogether, the plant fossil assemblages indicate humid and warm temperate conditions, which is in contrast to recent palaeoclimatic models that predict cool temperate climates for the continental interior of southern Gondwana during the Jurassic. However, there is no evidence for notable soil development or peat accumulation. The environmental conditions were apparently very unstable due to intense volcanic activity that resulted in frequent perturbation of landscape and vegetation, hampering the development of long-lived climax communities. Cuticles of bennettitaleans and conifers show xeromorphic features that may have been beneficial for growth in this volcanic environment.

The Eastern Otway Ranges, Victoria is an area recognised for its significant flora and fauna communities. An area of about 7000 ha, the Anglesea heathlands has been listed on the register of the National Estate. Although symptoms of the plant pathogen Phytophthora cinnamomi have been recorded in the area since the 1970s, the extent of infestation and its effects have not been documented. The aims of this study were to assess the distribution of infestation, identify the relationship of plant infection to site variables and to identify evidence of spread of the pathogen. The presence of P. cinnamomi was assessed at 50 study sites by a visual evaluation of the vegetation, using species such as Xanthorrhoea australis (Austral grass tree) and Isopogon ceratophyllus (horny cone bush) as indicator species. Soil and plant tissues were assayed for the presence of the pathogen by cotyledon baiting and immunoassay methods. Phytophthora cinnamomi was isolated at 76% of the study sites from the floristic communities identified: heathy open forest; heathy woodland I and II; Bald Hills heathland; riparian open forest. There were significantly more diseased sites at lower altitudes. The pathogen is widely spread and causing disease throughout the area, but at present often only in small patches. There is an urgent need for disease management to protect the significant communities. These findings suggest that management actions such as mapping current infestations, closing tracks and implementing vehicle wash-down points are required.

Bryophytic communities in plateau forests of mature Eucalyptus regnans are distributed according to substrate type and microclimate, whereas those in gully rainforests are more catholic. Objective classification of releves indicated the extent to which groupings are shared between these major topographic sites and the degree to which their distribution is mediated by differences in microclimate. Communities on many substrates in E. regnans forests are either seral to a fern floor 'climax' or exhibit pattern and process cycles of regenerative stability.

In the subalpine tract of the Bogong High Plains, cyclical patterns of regeneration occur within open heath and closed heath communities. In the Grevillea australis-Poa hiemata open grassy heath, most Grevillea shrubs are at present mature or senescent. Beneath the foliage of these shrubs, and in their canopy gaps, the dominant replacement species in the herb layer is snowgrass (Poa hiemata), and these shrubs tend to be replaced by snowgrass as they senesce. In the Phebalium squamulosum-Grevillea australis closed heath, both snowgrass and shrubs may occupy the senescent and gap phases of the dominant shrubs. Grazing by free-ranging cattle appears to favour the recolonisation of such gaps by shrubs rather than by Poa. In Prostanthera cuneata closed heath, regeneration in gaps was clearly shrub-dominated, with little establishment of snowgrass. Some shrubs, such as Grevillea, are obligate seed regenerators, whereas Phebalium and Prostanthera are capable of regeneration by both seed and vegetative means, such as root stock and layering stems. The life cycle of the major shrubs, from establishment to death, appears to require 30-50 years.

This thesis seeks to explain how site-scale design decisions can assist retention of rare plant communities concentrated in and near settled areas. To do so it focuses on a specific species and development context. Explanations are sought through examination of case studies of landuse developments in proximity to retained Garry oak plant communities located in the perimeter of Victoria, British Columbia. In the study region, exponential declines in species populations, health, and diversity of rare Garry oak ecosystems have been largely attributed to impacts from land-use developments. Over the past century, land-use developments have transformed the floral, spatial, structural and functional characteristics of the settled landscape. Isolated islands of imperiled plant associations remain on protected bioreserves: for recruitment and connectivity, these rare fauna rely on private-land greenways. Architectural teams have the potential to influence the decision-making processes that create ecologically-vital greenspace on private land, thereby enhancing survival for declining plant communities. Case-study evidence for the importance of land-use decisions on diminishing Garry oak meadow is gathered through vegetation surveys conducted on Garry oak meadow in proximity to six architectural projects on Victoria's western edge. Observed changes in growth extensions are then categorized in relation to human activities associated with built form, and correlated with principles from Landscape Ecology. An ARC of design strategies, developed in primary research by K. D. Rothley is adapted for architectural use as follows: firstly, AREA of a plant community is kept free of encroachment by the orderly frame established around vegetation; secondly, RARE SPECIES and habitat are identified with borders or signage; thirdly, CONNECTIVITY between retained landscapes is secured by siting roads and buildings to minimize ecosystem fragmentation. To effectively communicate preexisting landscape ecology principles, grouped under the ARC of strategies, illustrations and key-word phrases are developed. These principles, when integrated into architectural teams' structural knowledge, extend the architects' perceived role beyond aesthetics and economic efficiency. Enhancing habitat value through retention or restoration of rare ecosystems at the margins of suburban development, becomes an additional realm of influence for professional teams designing the spatial configurations of peri-urban landscapes.