1000 resultados para subtropical lake
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A travel article about food and landscape in Alberta. IN THE remote islands off Canada's east coast, I was given an old rule of survival: If you get lost in the forest, follow the bear tracks and eat what the bears eat, except skunk cabbage. There was no second rule for what to do about the bear, should he also appear. No matter. "Do this and you'll live," it says, "just as we did in the past."...
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Brisbane, the capital of Queensland, in South-East Queensland is situated on the Brisbane River, one of the largest rivers (and floodplains) on the east coast of Australia. The river defines the city and gives it its name. The river has been a natural place to accommodate some population growth for the city with high-density development that capitalises on the natural amenity, cycleways and a string of parks and the flatter land. The major floods of 2011 and the scare of 2013, has seen a more malevolent quality of the river and shift of thinking on its role within the city. The floods have made council, for the first time, acquire prime development sites near the river, with proposals for high density development and made them parks, at great cost. The pressure for population growth in Brisbane remains. 140,000 new dwellings are required by 2031. Brownfield sites are less plentiful and there is interest to rethink of some of the other strategic locations in the city away from the river on higher ground and steeper slopes. Some of these places are currently open spaces. Victoria Park Golf Course sits on a high ridge line and a very strategic part of the city just north of the city centre is one of the few remaining golf courses close to the centre of an Australian capital city. While it is a public course and a valuable community asset, it has been compromised by the recently completed northern busway with two bus stations constructed on its edges. It is bounded on the west and north-east by two major community facilities, the Queensland University of Technology (QUT) to the west and RBW Hospital at its northern end. In a city in need of urban consolidation, perhaps it is time to review the future of the golf course. This question has been investigated as a conjecture in the Master of Architecture program at the QUT. The project has been to re-imagine Victoria Park as a new city parkland and a place that makes an urban connection from the QUT to the hospital. This new urban precinct is be a medium to high-density transit oriented development that capitalises on the bus way stations and the proximity of the university and hospital. The precinct will frame/define/interact with the new major urban park for the city. A key question being addressed is how the design can embody and define principles of a subtropical urbanism. Students are identifying the appropriate street and block structure, density and built form to be accommodated on blocks that define and activate a rich sequence of streets and public spaces. The paper will present a critical overview of the project work that provides a lens to how future professionals may respond to these issue that will be the focus of their professional lives.
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A multi-season 15N tracer recovery experiment was conducted on an Oxisol cropped with wheat, maize and sorghum to compare crop N recoveries of different fertilisation strategies and determine the main pathways of N losses that limit N recovery in these agroecosystems. In the wheat and maize seasons, 15N-labelled fertiliser was applied as conventional urea (CONV) and urea coated with a nitrification inhibitor (DMPP). In sorghum, the fate of 15N-labelled urea was monitored in this crop following a legume ley pasture (L70) or a grass ley pasture (G100). The fertiliser N applied to sorghum in the legume-cereal rotation was reduced (70 kg N ha−1) compared to the grass-cereal (100 kg N ha−1) to assess the availability of the N residual from the legume ley pasture. Average crop N recoveries were 73 % (CONV) and 77 % (DMPP) in wheat and 50 % (CONV) and 51 % (DMPP) in maize, while in sorghum were 71 % (L70) and 53 % (G100). Data gathered in this study indicate that the intrinsic physical and chemical conditions of Oxisols can be extremely effective in limiting N losses via deep leaching or denitrification. Elevated crop 15N recoveries can be therefore obtained in subtropical Oxisols using conventional urea while in these agroecosystems DMPP urea has no significant scope to increase fertiliser N recovery in the crop. Overall, introducing a legume phase to limit the fertiliser N requirements of the following cereal crop proved to be the most effective strategy to reduce N losses and increase fertiliser N recovery.
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The Office of Urban Management recognises that the values which characterise the SEQ region as 'subtropical' are important determinants of form in urban and regional planning. Subtropical values are those qualities on which our regional identity depends. A built environment which responds positively to these values is a critical ingredient for achieving a desirable future for the region. The Centre for Subtropical Design has undertaken this study to identify the particular set of values which characterises SEQ, and to translate theses values into design principals that will maintain and reinforce the value set. The principles not only apply to the overall balance between the natural environment and the built environment, but can be applied by local government authorities to guide local planning schemes and help shape specific built for outcomes.
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This is the first study to investigate alternative fertilisation strategies to increase cereal production while reducing greenhouse gas emissions from the most common soil type in subtropical regions. The results of this research will contribute to define future farming practices to achieve global food security and mitigate climate change. The study established that introducing legumes in cropping systems is the most agronomically viable and environmentally sustainable fertilisation strategy. Importantly, this strategy can be widely adopted in subtropical regions since it is economically accessible, requires little know-how transfer and technology investment, and can be profitable in both low- and high-input cropping systems.
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The role of different chemical compounds, particularly organics, involved in the new particle formation (NPF) and its consequent growth are not fully understood. Therefore, this study was conducted to investigate the chemistry of aerosol particles during NPF events in an urban subtropical environment. Aerosol chemical composition was measured along with particle number size distribution (PNSD) and several other air quality parameters at five sites across an urban subtropical environment. An Aerodyne compact Time-of-Flight Aerosol Mass Spectrometer (c-TOF-AMS) and a TSI Scanning Mobility Particle Sizer (SMPS) measured aerosol chemical composition and PNSD, respectively. Five NPF events, with growth rates in the range 3.3-4.6 nm, were detected at two sites. The NPF events happened on relatively warmer days with lower humidity and higher solar radiation. Temporal percent fractions of nitrate, sulphate, ammonium and organics were modelled using the Generalised Additive Model (GAM), with a basis of penalised spline. Percent fractions of organics increased after the NPF events, while the mass fraction of ammonium and sulphate decreased. This uncovered the important role of organics in the growth of newly formed particles. Three organic markers, factors f43, f44 and f57, were calculated and the f44 vs f43 trends were compared between nucleation and non-nucleation days. f44 vs f43 followed a different pattern on nucleation days compared to non-nucleation days, whereby f43 decreased for vehicle emission generated particles, while both f44 and f43 decreased for NPF generated particles. It was found for the first time that vehicle generated and newly formed particles cluster in different locations on f44 vs f43 plot and this finding can be used as a tool for source apportionment of measured particles.
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Historic landscapes today are changing gradually or abruptly, and the abrupt changes have caused the loss of much historic information. How to identify and protect the significant evidence of dynamic landscapes is a question that must be answered by each cultural community. This paper establishes a decipherment process – an operational guide for landscape assessment in China. This is a methodology using European methods integrated with traditional Chinese ways of landscape appreciation, providing an effective approach to translate the cultural landscape framework into the conservation inventory. Using Slender West Lake as a case study, the decipherment process has expanded the existing landscape investigation theory using the factor of artistic conception to integrate intangible values into the assessment process. It has also established a unit-based method to classify and represent historic landscapes.
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Climate has been, throughout modern history, a primary attribute for attracting residents to the “Sunshine States” of Florida (USA) and Queensland (Australia). The first major group of settlers capitalized on the winter growing season to support a year-‐round agricultural economy. As these economies developed, the climate attracted tourism and retirement industries. Yet as Florida and Queensland have blossomed under beneficial climates, the stresses acting on the natural environment are exacting a toll. Southeast Florida and eastern Queensland are among the most vulnerable coastal metropolitan areas in the world. In these places the certainty of sea level rise is measurable with impacts, empirically observable, that will continue to increase regardless of any climate change mitigation.1 The cities of the subtropics share a series of paradoxes relating to climate, resources, environment, and culture. As the subtropical climate entices new residents and visitors there are increasing costs associated with urban infrastructure and the ravages of violent weather. The carefree lifestyle of subtropical cities is increasingly dependent on scarce water and energy resources and the flow of tangible goods that support a trade economy. The natural environment is no longer exploitable as the survival of the human environment is contingent upon the ability of natural ecosystems to absorb the impact of human actions. The quality of subtropical living is challenged by the mounting pressures of population growth and rapid urbanization yet urban form and contemporary building design fail to take advantage of the subtropical zone’s natural attributes of abundant sunshine, cooling breezes and warm temperatures. Yet, by building a global network of local knowledge, subtropical cities like Brisbane, the City of Gold Coast and Fort Lauderdale, are confidently leading the way with innovative and inventive solutions for building resiliency and adaptation to climate change. The Centre for Subtropical Design at Queensland University of Technology organized the first international Subtropical Cities conference in Brisbane, Australia, where the “fault-‐lines” of subtropical cities at breaking points were revealed. The second conference, held in 2008, shed a more optimistic light with the theme "From fault-‐lines to sight-‐lines -‐ subtropical urbanism in 20-‐20" highlighting the leadership exemplified in the vitality of small and large works from around the subtropical world. Yet beyond these isolated local actions the need for more cooperation and collaboration was identified as the key to moving beyond the problems of the present and foreseeable future. The spirit of leadership and collaboration has taken on new force, as two institutions from opposite sides of the globe joined together to host the 3rd international conference Subtropical Cities 2011 -‐ Subtropical Urbanism: Beyond Climate Change. The collaboration between Florida Atlantic University and the Queensland University of Technology to host this conference, for the first time in the United States, forges a new direction in international cooperative research to address urban design solutions that support sustainable behaviours, resiliency and adaptation to sea level rise, green house gas (GHG) reduction, and climate change research in the areas of architecture and urban design, planning, and public policy. With southeast Queensland and southern Florida as contributors to this global effort among subtropical urban regions that share similar challenges, opportunities, and vulnerabilities our mutual aim is to advance the development and application of local knowledge to the global problems we share. The conference attracted over 150 participants from four continents. Presentations by authors were organized into three sub-‐themes: Cultural/Place Identity, Environment and Ecology, and Social Economics. Each of the 22 papers presented underwent a double-‐blind peer review by a panel of international experts among the disciplines and research areas represented. The Centre for Subtropical Design at the Queensland University of Technology is leading Australia in innovative environmental design with a multi-‐disciplinary focus on creating places that are ‘at home’ in the warm humid subtropics. The Broward Community Design Collaborative at Florida Atlantic University's College for Design and Social Inquiry has built an interdisciplinary collaboration that is unique in the United States among the units of Architecture, Urban and Regional Planning, Social Work, Public Administration, together with the College of Engineering and Computer Science, the College of Science, and the Center for Environmental Studies, to engage in funded action research through design inquiry to solve the problems of development for urban resiliency and environmental sustainment. As we move beyond debates about climate change -‐ now acting upon us -‐ the subtropical urban regions of the world will continue to convene to demonstrate the power of local knowledge against global forces, thereby inspiring us as we work toward everyday engagement and action that can make our cities more livable, equitable, and green.
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There is currently a lack of reference values for indoor air fungal concentrations to allow for the interpretation of measurement results in subtropical school settings. Analysis of the results of this work established that, in the majority of properly maintained subtropical school buildings, without any major affecting events such as floods or visible mould or moisture contamination, indoor culturable fungi levels were driven by outdoor concentration. The results also allowed us to benchmark the “baseline range” concentrations for total culturable fungi, Penicillium spp., Cladosporium spp. and Aspergillus spp. in such school settings. The measured concentration of total culturable fungi and three individual fungal genera were estimated using Bayesian hierarchical modelling. Pooling of these estimates provided a predictive distribution for concentrations at an unobserved school. The results indicated that “baseline” indoor concentration levels for indoor total fungi, Penicillium spp., Cladosporium spp. and Aspergillus spp. in such school settings were generally ≤ 1450, ≤ 680, ≤ 480 and ≤ 90 cfu/m3, respectively, and elevated levels would indicate mould damage in building structures. The indoor/outdoor ratio for most classrooms had 95% credible intervals containing 1, indicating that fungi concentrations are generally the same indoors and outdoors at each school. Bayesian fixed effects regression modeling showed that increasing both temperature and humidity resulted in higher levels of fungi concentration.
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This study examined the potential for apartment living to become more socially and environmentally acceptable in Australian society generally, and in subtropical cities particularly. Resolution of incongruities between residents' preferred attributes and other stakeholders' main interests has important implications for reshaping lifestyle expectations and design practice as society moves toward a post-carbon future.
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Lake Purrumbete maar is located in the intraplate, monogenetic Newer Volcanics Province in southeastern Australia. The extremely large crater of 3000. m in diameter formed on an intersection of two fault lines and comprises at least three coalesced vents. The evolution of these vents is controlled by the interaction of the tectonic setting and the properties of both hard and soft rock aquifers. Lithics in the maar deposits originate from country rock formations less than 300. m deep, indicating that the large size of the crater cannot only be the result of the downwards migration of the explosion foci in a single vent. Vertical crater walls and primary inward dipping beds evidence that the original size of the crater has been largely preserved. Detailed mapping of the facies distributions, the direction of transport of base surges and pyroclastic flows, and the distribution of ballistic block fields, form the basis for the reconstruction of the complex eruption history,which is characterised by alternations of the eruption style between relatively dry and wet phreatomagmatic conditions, and migration of the vent location along tectonic structures. Three temporally separated eruption phases are recognised, each starting at the same crater located directly at the intersection of two local fault lines. Activity then moved quickly to different locations. A significant volcanic hiatus between two of the three phases shows that the magmatic system was reactivated. The enlargement of especially the main crater by both lateral and vertical growth led to the interception of the individual craters and the formation of the large circular crater. Lake Purrumbete maar is an excellent example of how complicated the evolution of large, seemingly simple, circular maar volcanoes can be, and raises the question if these systems are actually monogenetic.
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Dwellings in multi-storey apartment buildings (MSAB) are predicted to increase dramatically as a proportion of housing stock in subtropical cities over coming decades. The problem of designing comfortable and healthy high-density residential environments and minimising energy consumption must be addressed urgently in subtropical cities globally. This paper explores private residents’ experiences of privacy and comfort and their perceptions of how well their apartment dwelling modulated the external environment in subtropical conditions through analysis of 636 survey responses and 24 interviews with residents of MSAB in inner urban neighbourhoods of Brisbane, Australia. The findings show that the availability of natural ventilation and outdoor private living spaces play important roles in resident perceptions of liveability in the subtropics where the climate is conducive to year round “outdoor living”. Residents valued choice with regard to climate control methods in their apartments. They overwhelmingly preferred natural ventilation to manage thermal comfort, and turned to the air-conditioner for limited periods, particularly when external conditions were too noisy. These findings provide a unique evidence base for reducing the environmental impact of MSAB and increasing the acceptability of apartment living, through incorporating residential attributes positioned around climate-responsive architecture.
Rainfall variability drives interannual variation in N2O emissions from a humid, subtropical pasture
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Variations in interannual rainfall totals can lead to large uncertainties in annual N2O emission budget estimates from short term field studies. The interannual variation in nitrous oxide (N2O) emissions from a subtropical pasture in Queensland, Australia, was examined using continuous measurements of automated chambers over 2 consecutive years. Nitrous oxide emissions were highest during the summer months and were highly episodic, related more to the size and distribution of rain events than soil water content. Over 48% of the total N2O emitted was lost in just 16% of measurement days. Interannual variation in annual N2O estimates was high, with cumulative emissions increasing with decreasing rainfall. Cumulative emissions averaged 1826.7 ± 199.9 g N2O-N ha−1 yr−1 over the two year period, though emissions from 2008 (2148 ± 273 g N2O-N ha−1 yr−1) were 42% higher than 2007 (1504 ± 126 g N2O-N ha−1 yr−1). This increase in annual emissions coincided with almost half of the summer precipitation from 2007 to 2008. Emissions dynamics were chiefly driven by the distribution and size of rain events which varied on a seasonal and annual basis. Sampling frequency effects on cumulative N2O flux estimation were assessed using a jackknife technique to inform future manual sampling campaigns. Test subsets of the daily measured data were generated for the pasture and two adjacent land-uses (rainforest and lychee orchard) by selecting measured flux values at regular time intervals ranging from 1 to 30 days. Errors associated with weekly sampling were up to 34% of the sub-daily mean and were highly biased towards overestimation if strategically sampled following rain events. Sampling time of day also played a critical role. Morning sampling best represented the 24 hour mean in the pasture, whereas sampling at noon proved the most accurate in the shaded rainforest and lychee orchard.