996 resultados para landscape resilience


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We investigated changes in the spatial organization of individuals within a population of endangered Southern Bell Frogs Litoria raniformis over an eight-month period. Our results identified strong temporal changes in both spatial organization and the apparent location of L. raniformis within the study site. Ripley's K Function analyses showed that the position of individuals relative to one another shifted from random immediately after the study site was flooded (p < 0.005), to strongly clustered at spatial scales between 0-1 500 m during the peak breeding period (p < 0.005). The majority of flooded areas were dry by April and May and individuals again became aggregated within the remaining waterbodies.

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Aim. We characterized changes in reporting rates and abundances of bird species over a period of severe rainfall deficiency and increasing average temperatures. We also measured flowering in eucalypts, which support large numbers of nectarivores characteristic of the region.

Location.  A 30,000-km2 region of northern Victoria, Australia, consisting of limited amounts of remnant native woodlands embedded in largely agricultural landscapes.

Methods. There were three sets of monitoring studies, pitched at regional  (survey programmes in 1995–97, 2004–05 and 2006–08), landscape (2002–03 and 2006–07) and site (1997–2008 continuously) scales. Bird survey techniques used a standard 2-ha, 20-min count method. We used Bayesian analyses of reporting rates to document statistically changes in the avifauna through time at each spatial scale.

Results. Bird populations in the largest remnants of native vegetation (up to 40,000 ha), some of which have been declared as national parks in the past decade, experienced similar declines to those in heavily cleared andscapes. All categories of birds (guilds based on foraging substrate, diet, nest site; relative mobility; geographical distributions) were affected similarly. We detected virtually no bird breeding in the latest survey periods. Eucalypt flowering has declined significantly over the past 12 years of drought.

Main conclusions. Declines in the largest woodland remnants commensurate with those in cleared landscapes suggest that reserve systems may not be relied upon to sustain species under climate change. We attribute population declines to low breeding success due to reduced food. Resilience of bird populations in this woodland system might be increased by active management to enhance habitat quality in existing vegetation and restoration of woodland in the more fertile parts of landscapes.

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Human modification of landscapes typically results in many species being confined to small, isolated and degraded habitat fragments. While fragment size and isolation underpin many studies of modified landscapes, vegetation characteristics are less frequently incorporated. The relative influence of biogeographic (e.g. size, isolation) and vegetation parameters on assemblages is poorly understood, but critical for conservation management. In this study, a multiple hypothesis testing framework was used to determine the relative importance of biogeographic and vegetation parameters in explaining the occurrence of an assemblage of small mammals in 48 forest fragments in an agricultural landscape in south-eastern Australia. Fragment size and vegetation characteristics were consistently important predictors of occurrence across species. In contrast, fragment isolation was important for just one native species. Differing abilities of species to move through the landscape provide a reasonable explanation for these results. We conclude that for effective conservation of assemblages, it is important to: (1) consider differing responses of species to landscape change, and (2) move beyond a focus primarily on spatial attributes (size, isolation) to recognise that landscape change also has profound effects on habitat composition and quality.

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The Picturesque aesthetic emerged in the later 18th century, uniting the Sublime and the Beautiful and had its roots in the paintings of Claude Lorrain. In Britain, and in Australia, it came to link art, literature and landscape with architecture. The Picturesque aesthetic informed much of colonial culture which was achieved, in part, through the production and dissemination of architectural pattern books catering for the aspirations of the rising middle classes. This was against a background of political change including democratic reform. The Italianate villa, codified and promoted in such pattern books, was a particularly successful synthesis of style, form and function. The first Italianate villa in England, Cronkhill (1803) by John Nash contains all the ingredients which were essential to the model and had a deeper meaning. Deepdene (from 1807) by Thomas Hope gave the model further impetus. The works of Charles Barry and others in a second generation confirmed the model's acceptability. In Britain, its public status peaked with Osborne House (from 1845), Queen Victoria's Italianate villa on the Isle of Wight, Robert Kerr used a vignette of Osborne House on the title page of his sophisticated and influential pattern book, The Gentleman's House (1864,1871). It was one of many books, including those of J.C, Loudon and AJ. Downing, current in colonial Victoria. The latter authors and horticulturists were themselves villa dwellers with libraries and orchards, two criteria for the true villa lifestyle. Situation and a sense of retreat were the two further criteria for the villa lifestyle. As the new colony of Victoria blossomed between 1851 and 1891, the Italianate villa, its garden setting and its landscape siting captured the tenor of the times. Melbourne, the capital was a rich manufacturing metropolis with a productive hinterland and international markets. The people enjoyed a prosperity and lifestyle which they wished to display. Those who had a position in society were keen to demonstrate and protect it. Those with aspirations attempted to provide the evidence necessary for such acceptance, The model matured and became ubiquitous. Its evolution can be traced through a series of increasingly complicated rural and suburban examples, a process which modernist historians have dismissed as a decadent decline. These villas, in fact, demonstrate an increasingly sophisticated retreat by merchants from ‘the Town’ and by graziers from ‘the Country’. In both town and country, the towers of villas mark territory newly acquired. The same claim was often made in humbler situations. Government House, Melbourne (from 1871), a splendid Italianate villa and arguably finer than Osborne House, was set in a cultivated landscape and towered above all It incorporated the four criteria and, in addition, claimed its domain, focused authority and established the colony's social status. It symbolised ancient notions of democracy and idealism but with a modem appreciation for the informal and domestic. Government House in Melbourne is the epitome of the Italianate villa in the colonial landscape and is the climax of the Picturesque aesthetic in Victoria.

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[No Abstract]

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Habitat loss and fragmentation are recognized as primary drivers of biodiversity loss worldwide. To understand the functional effects of habitat fragmentation on bird populations, data on movement across gaps in habitat cover are necessary, although rarely available. In this study, we used call playback to simulate a conspecific territorial intruder to entice birds to move through the landscape in a predictable and directional manner. We then quantified the probability of movement in continuous forest and across cleared gaps for two forest-dependent species, the grey shrike-thrush (Colluricincla harmonica) and the white-throated treecreeper (Cormobates leucophaeus). Fifty-four playback trials were conducted for each species across distances ranging from 25 to 480 m in continuous forest and 15-260 m across gaps in a forest-agricultural landscape in southern Victoria, Australia. The probability of movement was significantly reduced by gaps in forest cover for both species. Shrike-thrushes were six times more likely to move 170 m in continuous forest than to cross 170-m gaps. The mean probability that treecreepers would cross any gap at all was less than 0.5, and they were three times less likely to move 50 m across a gap than through continuous forest. Both species displayed non-linear responses to increasing gap distance: we identified a gap-tolerance threshold of 85 m for the shrike-thrush and 65 m for the treecreeper beyond which individuals were most unlikely to cross. The presence of scattered paddock trees increased functional connectivity for the shrike-thrush, with individuals crossing up to 260 m when scattered trees were present. We conclude that gaps in habitat cover are barriers to movement, and that characteristics of the intervening matrix influence landscape permeability.

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Restoration of native vegetation is required in many regions of the world, but determining priority locations for revegetation is a complex problem. We consider the problem of determining spatial and temporal priorities for revegetation to maximize habitat for 62 bird species within a heavily cleared agricultural region, 11 000 km2 in area. We show how a reserve-selection framework can be applied to a complex, large-scale restoration-planning problem to account for multi-species objectives and connectivity requirements at a spatial extent and resolution relevant to management. Our approach explicitly accounts for time lags in planting and development of habitat resources, which is intended to avoid future population bottlenecks caused by delayed provision of critical resources, such as tree hollows. We coupled species-specific models of expected habitat quality and fragmentation effects with the dynamics of habitat suitability following replanting to produce species-specific maps for future times. Spatial priorities for restoration were determined by ranking locations (150-m grid cells) by their expected contribution to species habitat through time using the conservation planning tool, ‘‘Zonation.’’ We evaluated solutions by calculating expected trajectories of habitat availability for each species. We produced a spatially explicit revegetation schedule for the region that resulted in a balanced increase in habitat for all species. Priority areas for revegetation generally were clustered around existing vegetation, although not always. Areas on richer soils and with high rainfall were more highly ranked, reflecting their potential to support high-quality habitats that have been disproportionately cleared for agriculture. Accounting for delayed development of habitat resources altered the rank-order of locations in the derived revegetation plan and led to improved expected outcomes for fragmentation-sensitive species. This work demonstrates the potential for systematic restoration planning at large scales that accounts for multiple objectives, which is urgently needed by land and natural resource managers.

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Looking out from a vantage point across a large tract of forest gives a superficial impression of uniformity: the crowns of canopy trees follow the folds and contours of the landscape to provide a continuous cover of wooded vegetation. But this visual appearance belies the truth: forested landscapes are far from uniform. On closer examination, they comprise a complex mosaic of different vegetation types and and stands of different age-classes, differing structural features, and modified to a varying extent by human land-uses. Forests have a critical role in the conservation of biodiversity throughout the world (Peterken 1996; Laurance and Bierregard 1997; Lindenmayer and Franklin 2002) and a key feature contributing to their conservation value is the response of forest biota to the heterogeneity inherent in forested landscapes (Lindenmayer et al. 2006). Consequently, an understanding of the implications of landscape structure for the maintainance of species and ecological processes is an important foundation for forest management and biodiversity conservation.

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ln multicultural Australia, the development of positive intercultural attitudes is essential in the creation of a harmonious society. Music education is a powerful medium to address cultural inclusivity. The 2005 National Review of School Music Education challenges Australian higher education institutions to prepare programs that explore multiculturalism to engender tolerance.This research explored how final year teacher education students at Monash University and Deakin University (Victoria, Australia) engage with music of other cultures and how this affects their understanding of cultural diversity in school music. From 2005 to 2008, teacher education students undertaking music methodologies were invited to participate in semi-structured interviews.The data collected from the interviews were transcribed and analyzed using interpretative phenomenological analysis, and from these data, we developed patterns of meaning that are reported thematically; student teachers' beliefs, attitudes, and understandings of multiculturalism and the classroom realities of multiculturalism.The findings contribute to how we, as tertiary educators, evaluate our role and programs.

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Demonstrates that a personality type typified by self-perceptions tinged with a positive bias and high levels of optimism, provides protection, or resilience, from the experience of depression. Suggests that vulnerability to depression can be attributed to an inability to develop positively biased self-perceptions.

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Small mammals displayed contrasting patterns of occurence in forest fragments. Population studies revealed that key processes responsible for survival in habitat patches include demographic flexibility and the movement of individuals between patches. Combining pattern- and process-based approaches provides a more complete understanding of fauna in modified landscapes.

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This study confirms the valuable contribution that agricultural landscapes make to bird conservation in Australia. While native vegetation is critical to conservation efforts, careful management of production land-use types may provide additional benefits. Results show that productive farm enterprises can make real contributions to the success of broader conservation goals.