1000 resultados para Standard fire


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On New Years Eve, 1922, the massive double-domed timber structure of Rudolf Steiner’s First Goetheanum was engulfed in flames and reduced to ashes. In an effort to make his spiritual teachings accessible to all people through the medium of architecture, Steiner had dedicated ten years to the project. Growing hostility towards his occult philosophy however, pointed to arson as the probable cause of the blaze. Not to be defeated, Steiner embarked upon a new design for a second Goetheanum that endeavoured to fulfil the same aim as its predecessor but on an even grander scale. Yet despite being borne out of the same ideational basis, the architectural expression of the second building was vastly different from the first. This paper examines these differences and investigates how the methods Steiner used to create his architecture influenced the final architectural products. Steiner recognised drawing as a creative instrument that could enrich the conceptual potential of his theoretical work, however, with no formal training as an architect and limited drawing ability, this exchange was somewhat limited. The ambiguity of Steiner’s drawings is countered to some extent though by the maquettes and models he produced, which help negotiate the gap between the immaterial idea and the material object. The shared three-dimensional nature of model making and architecture allowed Steiner a more direct means of articulating and mediating his esoteric ideas in built form than the two-dimensional nature of drawing, particularly given the undulating organic forms he enthusiastically employed. Nevertheless, models are still a form of architectural abstraction capable of leaving their own trace on the built work and the distinctive character of Steiner’s non-conventional models serve to illustrate this point. A comparison between Steiner’s models and the buildings themselves reveal the intimate relationship between process and product that exists in his work. While the loss of the first Goetheanum came as a crushing blow to Steiner, its destruction and reconstruction offered him a unique opportunity to reconsider aspects of the design that may have been flawed in the first instance – a situation he embraced unequivocally. What images recurred in his work and why? How did his architecture evolve? This essay will demonstrate how paper and plasticine were utilised in a highly individualised manner by Steiner as a bridge between idea and artefact, to allow new architectural forms to rise from the ashes and produce one of the twentieth century’s most extraordinary buildings.

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Much of northern Australia’s tropical savannas are subject to annual intense and extensive late dry season wildfires, much of this occurring on Aboriginal land. Based on the successful West Arnhem Land Fire Abatement (WALFA) model, which has resulted in significantly reduced greenhouse gas emissions, fire abatement programmes are planned for other significant regions of northern Australia. This study offers an introduction to the ideas behind a proposed environmental and social benchmarking project that aims to evaluate the potential benefits of expanding the fire abatement program in northern Australia, under the leadership of NAILSMA and its partners. Gaining a better understanding of the biodiversity, social and cultural outcomes of these fire abatement activities is an important component of demonstrating multiple benefits of these programmes. We emphasize the role of both biodiversity and cultural mapping to establish benchmarks and baseline states, with the involvement of Indigenous communities being a key element to optimize social and biodiversity benefits. Consultation with Traditional Owners and ranger groups to establish an agreed set of targets, indicators and sampling protocols and methodologies are critical component of this process. Examples of preliminary work to date are provided.

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Fire is an important natural disturbance process within the Australian landscape, but the complex and hazardous nature of fire creates a conservation management dilemma. For landholders of private conservation lands, management for conservation of biodiversity and risk reduction is complicated. Private conservation landholders in eastern Australia directed far less effort towards fire management than other conservation management actions, despite clearly acknowledging the risk and associated responsibilities of fire management on their lands. Nonetheless, landholders did undertake actions to reduce fuel hazards and prepare for wildfire events on their land. Despite the established role and benefits of fire to many ecosystems in the region, landholder understanding of the ecological role of fire was generally poor. Few landholders were aware of ecologically appropriate fire regimes for the vegetation types on their property, and few undertook fire management actions to achieve ecological outcomes. Site-specific obstacles, lack of fire management knowledge and experience, and legal and containment concerns contributed to the low level of fire management observed. There is a need for property-specific fire management planning across all private conservation lands, to further integrate ecological fire requirements into biodiversity management, and prioritise actions that aim to improve conservation outcomes while safeguarding life and property.

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1.Fire is a major driver of ecosystem structure and function worldwide. It is also widely used as a management tool to achieve conservation goals. A common objective is the maintenance of 'fire mosaics' comprising spatially heterogeneous patches of differing fire history. However, it is unclear what properties of fire mosaics most enhance conservation efforts. Here we focus on the spatial and temporal properties of fire-prone landscapes that influence the distribution of small mammals.

2.We surveyed small mammals in 28 landscapes (each 12·6km2) representing a range of fire histories in the Murray Mallee region (104 000km2) of semi-arid Australia. Generalised linear mixed models were used to examine the influence of five landscape properties on the capture rate of individual species and the species richness of native small mammals. We investigated the influence of the proportional extent of fire age-classes, the diversity of fire age-classes, the extent of the dominant vegetation type, rainfall history and biogeographic context.

3.Three of four study species were associated with the spatial extent of fire age-classes. Older vegetation was found to provide important habitat for native small mammals. Overall, however, rainfall history and biogeographic context were dominant influences: for example, the species richness of native mammals was positively associated with above-average rainfall. There was little evidence that the diversity of fire age-classes influenced either the capture rate of individual species or species richness.

4.Synthesis and applications. In fire-prone environments, habitat availability can change markedly over short time-scales. Sufficient habitat at a suitable seral stage within the landscape is a key requirement for species conservation. In mallee ecosystems, the retention of older vegetation is recommended to create more desirable fire mosaics for native small mammals. In addition to such spatial properties of mosaics that are amenable to manipulation, an understanding of how ecological processes affect the biota (such as variation in rainfall-driven productivity) is also essential for informed conservation management.

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Fire is both a widespread natural disturbance that affects the distribution of species and a tool that can be used to manage habitats for species. Knowledge of temporal changes in the occurrence of species after fire is essential for conservation management in fire-prone environments. Two key issues are: whether postfire responses of species are idiosyncratic or if multiple species show a limited number of similar responses; and whether such responses to time since fire can predict the occurrence of species across broad spatial scales. We examined the response of bird species to time since fire in semiarid shrubland in southeastern Australia using data from surveys at 499 sites representing a 100-year chronosequence. We used nonlinear regression to model the probability of occurrence of 30 species with time since fire in two vegetation types, and compared species' responses with generalized response shapes from the literature. The occurrence of 16 species was significantly influenced by time since fire: they displayed six main responses consistent with generalized response shapes. Of these 16 species, 15 occurred more frequently in mid- or later-successional vegetation (>20 years since fire), and only one species occurred more often in early succession (<5 years since fire). The models had reasonable predictive ability for eight species, some predictive ability for seven species, and were little better than random for one species. Bird species displayed a limited range of responses to time since fire; thus a small set of fire ages should allow the provision of habitat for most species. Postfire successional changes extend for decades and management of the age class distribution of vegetation will need to reflect this timescale. Response curves revealed important seral stages for species and highlighted the importance of mid- to late-successional vegetation (>20 years). Although time since fire clearly influences the distribution of numerous bird species, predictive models of the spatial distribution of species in fire-prone landscapes need to incorporate other factors in addition to time since fire.

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Predicting the response of faunal communities to fire presents a challenge for land managers worldwide because the post-fire responses of species may vary between locations and fire events. Post-fire recovery can occur via nucleated recovery from in situ surviving populations or by colonization from ex situ populations. Fine-scale spatial patterns in the patchiness of fires and the proximity of burnt sites to source populations may contribute to both the variability in post-fire responses and the processes by which populations recover. We examined the avifauna at recently burnt sites within extensive semi-arid shrublands of south-eastern Australia, including 72 sites < 5 years since fire and 26 sites 10 years since fire. Study sites represented a gradient of increasing distance from ‘unburnt’ vegetation (i.e. > 27 years since fire) and varied in the presence or absence of small (25–900 m2) unburnt patches of vegetation. For sites < 5 years since fire, species richness was higher at sites closer to unburnt vegetation and at sites containing unburnt patches. These patterns were no longer evident at sites of 10 years since fire. The probability of occurrence of three of seven bird species modelled decreased with increasing distance to unburnt vegetation, but this pattern was evident only at sites burnt uniformly. One species was found almost exclusively at patchily burnt sites. These results are consistent with the hypothesis that proximity to unburnt vegetation enhances post-fire occupancy, and that colonization from ex situ populations is an important process for post-fire recovery of avifauna. Additionally, small unburnt patches enhance the rapid recovery of assemblages post-fire. These patterns are important for understanding the dynamics of post-fire population recovery. We recommend that management of fire for ecological purposes should explicitly consider the role that the spatial attributes of fires play in determining the post-fire community.

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PURPOSE. To compare frequency-doubling technology (FDT) perimetry with standard automated perimetry (SAP) for detecting glaucomatous visual field progression in a longitudinal prospective study.

METHODS. One eye of patients with open-angle glaucoma was tested every 6 months with both FDT and SAP. A minimum of 6 examinations with each perimetric technique was required for inclusion. Visual field progression was determined by two methods: glaucoma change probability (GCP) analysis and linear regression analysis (LRA). For GCP, several criteria for progression were used. The number of locations required to classify progression with FDT compared with SAP, respectively, was 1:2 (least conservative), 1:3, 2:3, 2:4, 2:6, 2:7, 3:6, 3:7, and 3:10 (most conservative). The number of consecutive examinations required to confirm progression was 2-of-3, 2-of-2, and 3-of-3. For LRA, the progression criterion was any significant decline in mean threshold sensitivity over time in each of the following three visual field subdivisions: (1) all test locations, (2) locations in the central 10° and the superior and inferior hemifields, and (3) locations in each quadrant. Using these criteria, the proportion of patients classified as showing progression with each perimetric technique was calculated and, in the case of progression with both, the differences in time to progression were determined.

RESULTS. Sixty-five patients were followed for a median of 3.5 years (median number of examinations, 9). For the least conservative GCP criterion, 32 (49%) patients were found to have progressing visual fields with FDT and 32 (49%) patients with SAP. Only 16 (25%) patients showed progression with both methods, and in most of those patients, FDT identified progression before SAP (median, 12 months earlier). The majority of GCP progression criteria (15/27), classified more patients as showing progression with FDT than with SAP. Contrary to this, more patients showed progression with SAP than FDT, when analysed with LRA; e.g., using quadrant LRA 20 (31%) patients showed progression with FDT, 23 (35%) with SAP, and only 10 (15%) with both.

CONCLUSIONS. FDT perimetry detected glaucomatous visual field progression. However, the proportion of patients who showed progression with both FDT and SAP was small, possibly indicating that the two techniques identify different subgroups of patients. Using GCP, more patients showed progression with FDT than with SAP, yet the opposite occurred using LRA. As there is no independent qualifier of progression, FDT and SAP progression rates vary depending on the method of analysis and the criterion used.

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Purpose – Accounting and water industry experts are developing general-purpose water accounting (GPWA) to report information about water and rights to water. The system has the potential to affect water policies, pricing and management, and investment and other decisions that are affected by GPWA report users' understanding of water risks faced by an entity. It may also affect financial returns to accounting and auditing firms and firms in water industries. In this paper the authors aim to examine the roles of the accounting profession, water industries and other stakeholders in governing GPWA. Recognising that the fate of GPWA depends partly upon regulatory power and economics, they seek to apply regulatory theories that explain financial accounting standards development to speculate about the national and international future of GPWA.

Design/methodology/approach – Official documents, internal Water Accounting Standards Board documents and unstructured interviews underpin the authors' analysis.

Findings – The authors speculate about the benefits that might accrue to various stakeholder groups from capturing the GPWA standard-setting process. They also suggest that internationally, water industries may dominate early GPWA standards development in the public interest and that regulatory capture by accounting or water industry professionals will not necessarily conflict with public interest benefits.

Practical implications – Accounting for water can affect allocations of environmental, economic, social and other resources; also, accounting and water industry professional standing and revenues. In this paper the authors identify factors influencing GPWA standards and standard-setting institutional arrangements, and thereby these resource allocations. The paper generates an awareness of GPWA's emergence and practical implications.

Originality/value –
This is an early study to investigate water accounting standard-setting regulatory influences and their impact.

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Box-Ironbark forests extend across a swathe of northern Victoria on the inland side of the Great Dividing Range. Although extensively cleared and modified, they support a distinctive suite of plants and animals. Historical fire regimes in this ecosystem are largely unknown, as are the effects of fire on most of the biota. However, knowledge of the ecological attributes of plant species has been used to determine minimum and maximum tolerable fire intervals for this ecosystem to guide current fire management. Here, we consider the potential effects of planned fire in the context of major ecological drivers of the current box-ironbark forests: namely, the climate and physical environment; historical land clearing and fragmentation; and extractive land uses. We outline an experimental management and research project based on application of planned burns in different seasons (autumn, spring) and at different levels of burn cover (patchy, extensive). A range of ecological attributes will be monitored before and after burns to provide better understanding of the landscape-scale effects of fire in box-ironbark forests. Such integration of management and research is essential to address the many knowledge gaps in fire ecology, particularly in the context of massively increased levels of planned burning currently being implemented in Victoria.