The exchange: an experiment in environmentally sustainable urban practice for a subtropical climate

The exchange pavilion offers a dialogue between two Expositions: 1998 in Brisbane and 2010 in Shanghai; and a chance to examine the impact that climate change will have on urban best practice outcomes in cities of the future. The Exchange exhibits the proposition that environmentally sustainable buildings need to interact responsively with a range of technical innovations to enable communities (and hence cities) to control and better manage their immediate environment. The 'Exchange' pavilion is a design experiment that integrates 3 key research elements: * An interactive digital exchange * A living green system wall (vertical and temporal) * A public urban star (horizontal and spatial) The proposition argues that the environmentally sustainability of any city is reliant on harnessing the full spectrum of intellectual and creative capital of the winder community (from universities to Government bodies to citizens) - a true knowledge city.

Endotoxins in indoor air and settled dust in primary schools in a subtropical climate

Endotoxins can significantly affect the air quality in school environments. However, there is currently no reliable method for the measurement of endotoxins and there is a lack of reference values for endotoxin concentrations to aid in the interpretation of measurement results in school settings. We benchmarked the “baseline” range of endotoxin concentration in indoor air, together with endotoxin load in floor dust, and evaluated the correlation between endotoxin levels in indoor air and settled dust, as well as the effects of temperature and humidity on these levels in subtropical school settings. Bayesian hierarchical modeling indicated that the concentration in indoor air and the load in floor dust were generally (<95th percentile) < 13 EU/m3 and < 24,570 EU/m2, respectively. Exceeding these levels would indicate abnormal sources of endotoxins in the school environment, and the need for further investigation. Metaregression indicated no relationship between endotoxin concentration and load, which points to the necessity for measuring endotoxin levels in both the air and settled dust. Temperature increases were associated with lower concentrations in indoor air and higher loads in floor dust. Higher levels of humidity may be associated with lower airborne endotoxin concentrations.

The lag effects and vulnerabilities of temperature effects on cardiovascular disease mortality in a subtropical climate zone in China

This research quantifies the lag effects and vulnerabilities of temperature effects on cardiovascular disease in Changsha—a subtropical climate zone of China. A Poisson regression model within a distributed lag nonlinear models framework was used to examine the lag effects of cold- and heat-related CVD mortality. The lag effect for heat-related CVD mortality was just 0–3 days. In contrast, we observed a statistically significant association with 10–25 lag days for cold-related CVD mortality. Low temperatures with 0–2 lag days increased the mortality risk for those ≥65 years and females. For all ages, the cumulative effects of cold-related CVD mortality was 6.6% (95% CI: 5.2%–8.2%) for 30 lag days while that of heat-related CVD mortality was 4.9% (95% CI: 2.0%–7.9%) for 3 lag days. We found that in Changsha city, the lag effect of hot temperatures is short while the lag effect of cold temperatures is long. Females and older people were more sensitive to extreme hot and cold temperatures than males and younger people.

Airborne culturable fungi in naturally ventilated primary school environments in a subtropical climate

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.

Investigation of the effect of balconies on natural ventilation of dwellings in high-rise residential buildings in subtropical climate

Balconies, as one of the main architectural features in subtropical climates, are assumed to enhance the ventilation performance of buildings by redirecting the wind. Although there are some studies on the effect of balconies on natural ventilation inside buildings, the majority have been conducted on single zone buildings with simple geometries. The purpose of this study is to explore the effect of balconies on the internal air flow pattern and ventilation performance of multi-storey residential buildings with internal partitions. To this end, a sample residential unit was selected for investigation and three different conditions tested, base case (no balcony), an open balcony and a semi-enclosed balcony. Computational Fluid Dynamics is used as an analysis method due to its accuracy and ability to provide detailed results. The cases are analysed in terms of average velocity, flow uniformity and number of Air Changes per Hour (ACH). The results suggest the introduction of a semi-enclosed balcony into high-rise dwellings improves the average velocity and flow uniformity. Integrating an open balcony results in reduction of the aforementioned parameters at 0° wind incidence.

Leaf nutritional levels in peach and nectarine grown in subtropical climate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Proceedings of the 3rd International Subtropical Cities Conference 2011 Subtropical Cities: Subtropical Urbanism -Beyond Climate Change

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.

The effect of various temperature indicators on different mortality categories in a subtropical city of Brisbane, Australia.

BACKGROUND: The relationship between temperature and mortality has been explored for decades and many temperature indicators have been applied separately. However, few data are available to show how the effects of different temperature indicators on different mortality categories, particularly in a typical subtropical climate. OBJECTIVE: To assess the associations between various temperature indicators and different mortality categories in Brisbane, Australia during 1996-2004. METHODS: We applied two methods to assess the threshold and temperature indicator for each age and death groups: mean temperature and the threshold assessed from all cause mortality was used for all mortality categories; the specific temperature indicator and the threshold for each mortality category were identified separately according to the minimisation of AIC. We conducted polynomial distributed lag non-linear model to identify effect estimates in mortality with one degree of temperature increase (or decrease) above (or below) the threshold on current days and lagged effects using both methods. RESULTS: Akaike's Information Criterion was minimized when mean temperature was used for all non-external deaths and deaths from 75 to 84 years; when minimum temperature was used for deaths from 0 to 64 years, 65-74 years, ≥ 85 years, and from the respiratory diseases; when maximum temperature was used for deaths from cardiovascular diseases. The effect estimates using certain temperature indicators were similar as mean temperature both for current day and lag effects. CONCLUSION: Different age groups and death categories were sensitive to different temperature indicators. However, the effect estimates from certain temperature indicators did not significantly differ from those of mean temperature.

The subtropical residential tower: An investigation by Design Charrette

QUT's Centre for Subtropical Design (CSD) partnered with a major developer to bring together some of Brisbane’s most experienced and creative architects and designers in a two-day intensive design charrette to propose innovative design strategies for naturally-ventilated high rise residential buildings. An inner-urban renewal site in Queensland’s capital city Brisbane gave four multi-disciplinary teams the opportunity to address a raft of issues that developers and consultants will confront more and more in the future in warm humid climates. The quest to release apartment dwellers from dependence on energy-hungry air-conditioning and artificial lighting was central to the design brief for the towers. Mentored by Richard Hassell of WOHA, the creative teams focussed on climate-responsive design principles for passive climate control including orientation, cross-ventilation and outdoor living in order to reduce greenhouse gas emissions and offset occupants’ rising energy costs. This article discusses how outcomes of the charrette take their cue from the city’s subtropical climate and demonstrate how high-density high-rise living can be attractive, affordable and sustainable through positive engagement with the subtropical climate’s natural attributes.

The subtropical row house charrette

Current urban development in South East Queensland (SEQ) is impacted by a number of factors: growth and sprawl eroding subtropical character and identity; changing demographics and housing needs; lack of developable land; rising transport costs; diminishing fresh water supply; high energy consumption; and generic building designs which ignore local climate, landscape and lifestyle conditions. The Subtropical Row House project sought to research ‘best practice’ planning and design for contemporary and future needs for urban development in SEQ, and stimulate higher-density housing responses that achieve sustainable, low-energy and low water outcomes and support subtropical character and identity by developing a workable new typology for homes that the local market can adopt. The methodology was that of charrette, an established methodology in architecture and design. Four leading Queensland architectural firms were invited to form multidisciplinary creative teams. During the two-day charrette, the teams visited a selected greenfield site, defined the problems and issues, developed ideas and solutions, and benchmarked performance of designs using the Australian Green Building Council’s Pilot Green Star Multi-Unit residential tool. Each of the four resulting designs simultaneously express a positive relationship with climate and place by demonstrating: suitability for the subtropical climate; flexibility for a diversity of households; integrated building/site/vegetation strategies; market appeal to occupants and developers; affordability in operation; constructability by ‘domestic’ builders; and reduced energy, water and wastage. The project was awarded a Regional Commendation by the Australian Institute of Architects.

Daylighting performance of subtropical multi-residential towers : simulations tools for design decisions

During an intensive design-led workshop multidisciplinary design teams examined options for a sustainable multi-residential tower on an inner urban site in Brisbane (Australia). The main aim was to demonstrate the key principles of daylight to every habitable room and cross-ventilation to every apartment in the subtropical climate while responding to acceptable yield and price points. The four conceptual design proposals demonstrated a wide range of outcomes, with buildings ranging from 15 to 30 storeys. Daylight Factor (DF), view to the outside, and the avoidance of direct sunlight were the only quantitative and qualitative performance metrics used to implement daylighting to the proposed buildings during the charrette. This paper further assesses the daylighting performance of the four conceptual designs by utilizing Climate-based daylight modeling (CBDM), specifically Daylight Autonomy (DA) and Useful Daylight Illuminance (UDI). Results show that UDI 100-2000lux calculations provide more useful information on the daylighting design than DF. The percentage of the space with a UDI <100-2000lux larger than 50% ranged from 77% to 86% of the time for active occupant behaviour (occupancy from 6am to 6pm). The paper also highlights the architectural features that mostly affect daylighting design in subtropical climates.

Rejuvenating lost and disused space within Fortitude Valley : a study into the effectiveness of urban greenery in subtropical public space

An issue gaining prominence in our urban environments in the notion of lost space, the undesirable urban areas that are in need of redesign, commonly caused by a focus on development as individual architectural entities, without a greater view of the urban environment as a holistic entity. Within the context of South East Queensland, the suburb of Fortitude Valley has been earmarked for development as an extension of the current CBD. With lost and disused spaces already existing throughout the suburb due to rapid growth and mismatched developments, recent planning regimes have proposed rejuvenation in the form of proposals that echo typologies from other Australian regions, such as the laneway typology from Melbourne. Opportunities exist in these spaces for design approaches that relate specifically to the individual and unique subtropical character of the area. This research explores the relationship between innovative approaches towards urban greenery as a means to rejuvenate lost and disused public space, and its suitability within a subtropical climate, specifically focused within the suburb of Fortitude Valley. A trend gaining prominence is the notion of biophilic cities; cities that integrate urban greenery as a means to provide vibrant public spaces, and meet the growing aesthetic, social, cultural and economic needs of our cities. Through analysis of case studies showcasing greenery in an inventive way, observations of public using subtropical public space, and a discussion of the current policy frameworks at place within Fortitude Valley, innovative uses of urban greenery is proposed as viable placemaking technique in subtropical urban environments.

Strawberry breeding in a subtropical environment

Strawberry breeding aims to provide cultivars that maximise consumer satisfaction and producer profitability in a changing environment. In this paper some concepts of profitability, consumer satisfaction and sustainability are explored for a subtropical climate using Queensland Australia, and Florida USA, as examples. The typical production environment is annual autumn planting of bare rooted runners into polythene covered raised beds at about 40000 plants/ha. Harvesting is late autumn to early spring, with fruit arriving at the major markets up to 2000km away from the production area within 1-4 days of harvest. The basic premise in the breed-big work is that consumers must enjoy the experience of eating strawberries, and that perceived flavour, sweetness, and juiciness are the major contributors to this experience. Using market chain information, we developed a basic value model comprised of costs, returns, and sustainability of market. To this basic outline are applied operational descriptors, such as 'speed of harvest', and associated plant characteristics, such as 'fruit display'. The expression of each plant characteristic is ascribed a value or level and together numerically describe the phenotype. This description is mathematically manipulated to provide a 'value index' for the cultivar. Nine cultivars including 'Strawberry Festival', 'Kabarla', 'DPI Rubygem' and 'Sweet Charlie' are described, and environmental issues that may impact on the subtropical strawberry breeding objectives are discussed. Product differentiation and the use of exotic germplasm as a new source of genes for flavour and resistance to disease and environmental stress will likely be the cornerstones of future progress in subtropical strawberry breeding. This approach should satisfy both consumers and producers.

Small-scale spatial and temporal variability in growth and mortality of fish larvae in the subtropical northcentral Gulf of Mexico: implications for assessing recruitment success

Extensive plankton collections were taken during seven September cruises (1990–93) along the inner continental shelf of the northcentral Gulf of Mexico (GOM). Despite the high productivity and availability of food during these cruises, significant small-scale spatial variability was found in larval growth rates for both Atlantic bumper (Chloroscombrus chrysurus, Carangidae) and vermilion snapper (Rhomboplites aurorubens, Lutjanidae). The observed variability in larval growth rates was not correlated with changes in water temperature or associated with conspicuous hydrographic features and suggested the existence of less-recognizable regions where conditions for growth vary. Cruise estimates of mortality coefficients (Z) for larval Atlantic bumper (n=32,241 larvae from six cruises) and vermilion snapper (n= 2581 larvae from four cruises) ranged from 0.20 to 0.37 and 0.19 to 0.29, respectively. Even in a subtropical climate like the GOM, where larval-stage durations may be as short as two weeks, observed variability in growth rates, particularly when combined with small changes in mortality rates, can cause order-of-magnitude differences in cumulative larval survival. To what extent the observed differences in growth rates at small spatial scales are fine-scale “noise” that ultimately is smoothed by larger-scale processes is not known. Future research is needed to further characterize the small-scale variability in growth rates of larvae, particularly with regard to microzooplankton patchiness and the temporal and spatial pattern of potential predators. Small-scale spatial variability in larval growth rates may in fact be the norm, and understanding the implications of this subtle mosaic may help us to better evaluate our ability to partition the causes of recruitment variability.