55 resultados para temperate forest


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PURPOSE: Heat stress might attenuate the effects of carbohydrate on immunoendocrine responses to exercise by increasing endogenous glucose production and reducing the rate of exogenous carbohydrate oxidation. The authors compared the efficacy of carbohydrate consumption on immune responses to exercise in temperate vs. hot conditions. METHODS: Ten male cyclists exercised on 2 separate occasions in temperate (18.1 +/- 0.4 degrees C, 58% +/- 8% relative humidity) and on another 2 occasions in hot conditions (32.2 +/- 0.7 degrees C, 55% +/- 2% relative humidity). On each occasion, the cyclists exercised in a fed state for 90 min at approximately 60% VO2max and then completed a 16.1-km time trial. Every 15 min during the first 90 min of exercise, they consumed 0.24 g/kg body mass of a carbohydrate or placebo gel. RESULTS: Neutrophil counts increased during exercise in all trials (p < .05) and were significantly lower (40%, p = .006) after the carbohydrate than after the placebo trial in 32 degrees C. The concentrations of serum interleukin (IL)-6, IL-8, and IL-10 and plasma granulocyte-colony-stimulating factor, myeloperoxidase, and calprotectin also increased during exercise in all trials but did not differ significantly between the carbohydrate and placebo trials. Plasma norepinephrine concentration increased during exercise in all trials and was significantly higher (50%, p = .01) after the carbohydrate vs. the placebo trial in 32 degrees C. CONCLUSION: Carbohydrate ingestion attenuated neutrophil counts during exercise in hot conditions, whereas it had no effect on any other immune variables in either temperate or hot conditions.

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This thesis investigates patterns of evolution in a group of native Australo-Papuan rodents. Past climatic change and associated sea level fluctuations, and fragmentation of wet forests in eastern Australia has facilitated rapid radiation, diversification and speciation in this group. This study adds to our understanding of the evolution of Australia’s rainforest fauna and describes the evolutionary relationships of a new genus of Australian rodent.

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Temperate Australia sits between the heat engine of the tropics and the cold Southern Ocean, encompassing a range of rainfall regimes and falling under the influence of different climatic drivers. Despite this heterogeneity, broad-scale trends in climatic and environmental change are evident over the past 30 ka. During the early glacial period (∼30–22 ka) and the Last Glacial Maximum (∼22–18 ka), climate was relatively cool across the entire temperate zone and there was an expansion of grasslands and increased fluvial activity in regionally important Murray–Darling Basin. The temperate region at this time appears to be dominated by expanded sea ice in the Southern Ocean forcing a northerly shift in the position of the oceanic fronts and a concomitant influx of cold water along the southeast (including Tasmania) and southwest Australian coasts. The deglacial period (∼18–12 ka) was characterised by glacial recession and eventual disappearance resulting from an increase in temperature deduced from terrestrial records, while there is some evidence for climatic reversals (e.g. the Antarctic Cold Reversal) in high resolution marine sediment cores through this period. The high spatial density of Holocene terrestrial records reveals an overall expansion of sclerophyll woodland and rainforest taxa across the temperate region after ∼12 ka, presumably in response to increasing temperature, while hydrological records reveal spatially heterogeneous hydro-climatic trends. Patterns after ∼6 ka suggest higher frequency climatic variability that possibly reflects the onset of large scale climate variability caused by the El Niño/Southern Oscillation.

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Objective: To examine the epidemiology and burden of respiratory illness during winter in urban children from temperate Australia. Methods: We conducted a cohort study of healthy Melbourne children, aged from 12 to 71 months. Parents kept a daily respiratory symptom diary and recorded resource use when an influenza-like illness (ILI) occurred. Results: One-hundred and eighteen children had 137 ILI episodes over 12 weeks for a rate of 0.53 ILI episodes per child-month (95% CI 0.44-0.61). Risk factors for ILI included younger age, fewer people residing in the household, structured exposure to other children outside the home, and a higher household income. Episodes had a mean duration of 10.4 days with 64 visits to a general practitioner (46.7 GP visits per 100 episodes), 27 antibiotic courses prescribed (19.7 antibiotic courses per 100 episodes), and three overnight hospitalizations (2.2 admissions per 100 episodes). Parents reported an average of 11.7 h excess time spent caring for a child per episode. Conclusions: Respiratory illnesses are a common and largely neglected cause of illness in Australian children. Pathogen-specific data are required to better assess the likely impact of available and developing vaccines and other treatment options.

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BACKGROUND Mosquito-borne diseases are climate sensitive and there has been increasing concern over the impact of climate change on future disease risk. This paper projected the potential future risk of Barmah Forest virus (BFV) disease under climate change scenarios in Queensland, Australia. METHODS/PRINCIPAL FINDINGS We obtained data on notified BFV cases, climate (maximum and minimum temperature and rainfall), socio-economic and tidal conditions for current period 2000-2008 for coastal regions in Queensland. Grid-data on future climate projections for 2025, 2050 and 2100 were also obtained. Logistic regression models were built to forecast the otential risk of BFV disease distribution under existing climatic, socio-economic and tidal conditions. The model was applied to estimate the potential geographic distribution of BFV outbreaks under climate change scenarios. The predictive model had good model accuracy, sensitivity and specificity. Maps on potential risk of future BFV disease indicated that disease would vary significantly across coastal regions in Queensland by 2100 due to marked differences in future rainfall and temperature projections. CONCLUSIONS/SIGNIFICANCE We conclude that the results of this study demonstrate that the future risk of BFV disease would vary across coastal regions in Queensland. These results may be helpful for public health decision making towards developing effective risk management strategies for BFV disease control and prevention programs in Queensland.

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Spatially-explicit modelling of grassland classes is important to site-specific planning for improving grassland and environmental management over large areas. In this study, a climate-based grassland classification model, the Comprehensive and Sequential Classification System (CSCS) was integrated with spatially interpolated climate data to classify grassland in Gansu province, China. The study area is characterized by complex topographic features imposed by plateaus, high mountains, basins and deserts. To improve the quality of the interpolated climate data and the quality of the spatial classification over this complex topography, three linear regression methods, namely an analytic method based on multiple regression and residues (AMMRR), a modification of the AMMRR method through adding the effect of slope and aspect to the interpolation analysis (M-AMMRR) and a method which replaces the IDW approach for residue interpolation in M-AMMRR with an ordinary kriging approach (I-AMMRR), for interpolating climate variables were evaluated. The interpolation outcomes from the best interpolation method were then used in the CSCS model to classify the grassland in the study area. Climate variables interpolated included the annual cumulative temperature and annual total precipitation. The results indicated that the AMMRR and M-AMMRR methods generated acceptable climate surfaces but the best model fit and cross validation result were achieved by the I-AMMRR method. Twenty-six grassland classes were classified for the study area. The four grassland vegetation classes that covered more than half of the total study area were "cool temperate-arid temperate zonal semi-desert", "cool temperate-humid forest steppe and deciduous broad-leaved forest", "temperate-extra-arid temperate zonal desert", and "frigid per-humid rain tundra and alpine meadow". The vegetation classification map generated in this study provides spatial information on the locations and extents of the different grassland classes. This information can be used to facilitate government agencies' decision-making in land-use planning and environmental management, and for vegetation and biodiversity conservation. The information can also be used to assist land managers in the estimation of safe carrying capacities which will help to prevent overgrazing and land degradation.

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Australian forestry plantations have doubled in the past 15 years, with rural communities harbouring a diverse range of positive and negative of economic, environmental and social impacts – the so-called triple bottom line (TBL). Utilising two Australian rural communities in Eden/Gippsland and Tasmania as qualitative case studies, this research explores how 23 non-forestry affiliated rural residents perceived and experienced the TBL economic, environmental and social impacts of plantation forestry. Residents criticised the economic plantation forestry benefits because of lengthy periods of inactivity and limited local employment, explaining that their community was reliant on the industry yet the promised economic benefits had never fully materialised. There was a sense the industry ‘plant and walk away.’ Residents were concerned about the environment impact on water quality, water tables and fire hazards, although they praised plantation forestry for carbon sequestering, eradicating erosion and water run-off. Negative social impacts were described, specifically how the land-use change from farming to forestry had significantly reduced the local population, employment and need for services. Natural resource management and communication strategies are offered, derived from non-forestry affiliated rural resident perspectives on how best to ensure sustainable forest development in their community.

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Barmah Forest virus (BFV) disease is the second most common mosquito-borne disease in Australia but few data are available on the risk factors. We assessed the impact of spatial climatic, socioeconomic and ecological factors on the transmission of BFV disease in Queensland, Australia, using spatial regression. All our analyses indicate that spatial lag models provide a superior fit to the data compared to spatial error and ordinary least square models. The residuals of the spatial lag models were found to be uncorrelated, indicating that the models adequately account for spatial and temporal autocorrelation. Our results revealed that minimum temperature, distance from coast and low tide were negatively and rainfall was positively associated with BFV disease in coastal areas, whereas minimum temperature and high tide were negatively and rainfall was positively associated with BFV disease (all P-value.

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Barmah Forest virus (BFV) disease is an emerging mosquito-borne disease in Australia. We aimed to outline some recent methods in using GIS for the analysis of BFV disease in Queensland, Australia. A large database of geocoded BFV cases has been established in conjunction with population data. The database has been used in recently published studies conducted by the authors to determine spatio-temporal BFV disease hotspots and spatial patterns using spatial autocorrelation and semi-variogram analysis in conjunction with the development of interpolated BFV disease standardised incidence maps. This paper briefly outlines spatial analysis methodologies using GIS tools used in those studies. This paper summarises methods and results from previous studies by the authors, and presents a GIS methodology to be used in future spatial analytical studies in attempt to enhance the understanding of BFV disease in Queensland. The methodology developed is useful in improving the analysis of BFV disease data and will enhance the understanding of the BFV disease distribution in Queensland, Australia.

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Interactive art installation Artist in Residence Queensland Government grant. Awarded June 2011 for period July-September 2011. This project involved co-creating an interactive artwork on site and in the forest with Grovely Primary school children aged 6-10, some with high needs. Affiliated with the United Nations International Year of the Forest. Final work is tangible, real-time visualization created using participatory design methods.

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The lesser short-tailed bat, Mystacina tuberculata, is the only native mammalian pollinator in New Zealand and the only fully temperate bat pollinator in the world. Although this unique status as a pollinator is well recognized, its reduced abundance and cryptic behaviour means little research has been undertaken to assess the contribution of the lesser short-tailed bat (hereafter ‘short-tailed bat’) to pollination in New Zealand. Accordingly, pollination by short-tailed bats has been assumed to be comparatively inconsequential, and the potential impacts of the bat's widespread extirpation have been overlooked. The recent discovery that the short-tailed bat is a major pollinator for at least some of the plants it visits emphasizes the importance of exploring this species' role as a pollinator. Here, our aim was to provide an assessment of the competition for short-tailed bat pollination through study of the temporal variation of flowering. Bats were sampled for pollen, and phenology surveys were conducted simultaneously. We found that the amount and type of pollen carried by the bats varied temporally, with one pollen type dominating samples at any given time. The two plants most consistently observed in the pollen samples flowered sequentially with little temporal overlap, suggesting that their flowering phenology may be adapted to minimize competition for the pollination services of the short-tailed bat.

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To maximize energetic savings, female bats often roost communally whilst pregnant or with non-volant dependents, whereas male bats more often roost alone; however, differences in selection of roosts by sex have not often been investigated. Better understanding of female colony locations could focus management to protect the majority of bats. New Zealand's long-tailed bat (Chalinolobus tuberculatus) roost in exotic plantation forest, where sex-specific roost selection has not been investigated, and therefore such management is not possible. We investigated sex-specific roost selection by long-tailed bats for the first time. Roosts and paired nonroosts were characterized testing predictions that males and females select roosts that differ from non-roosts, and males and females select different roosts. Females and males chose Pinus radiata roosts that differed from non-roost trees. Results suggest each sex chose roosts that maximized energetic savings. Female bats used roosts closer to water sources, that warmed earlier in the day, which allowed maintenance of high temperatures. Males appeared to choose roosts that allowed torpor use for long periods of the day. Males may be less selective with their roost locations than females, as they roosted further from water sources. This could allow persistence of male bats in marginal habitat. As all female long-tailed bats chose roosts within 150 m of waterways, management to protect bats could be focused here. To protect bats least able to escape when roosts are harvested, harvest of forest stands selected by female bats as roost sites should be planned when bats are not heavily pregnant nor have non-volant dependents.

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Clear-fell harvest of forest concerns many wildlife biologists because of loss of vital resources such as roosts or nests, and effects on population viability. However, actual impact has not been quantified. Using New Zealand long-tailed bats (Chalinolobus tuberculatus) as a model species we investigated impacts of clear-fell logging on bats in plantation forest. C. tuberculatus roost within the oldest stands in plantation forest so it was likely roost availability would decrease as harvest operations occurred. We predicted that post-harvest: (1) roosting range sizes would be smaller, (2) fewer roosts would be used, and (3) colony size would be smaller. We captured and radiotracked C. tuberculatus to day-roosts in Kinleith Forest, an exotic plantation forest, over three southern hemisphere summers (Season 1 October 2006–March 2007; Season 2 November 2007–March 2008; and Season 3 November 2008–March 2009). Individual roosting ranges (100% MCPs) post harvest were smaller than those in areas that had not been harvested, and declined in area during the 3 years. Following harvest, bats used fewer roosts than those in areas that had not been harvested. Over 3 years 20.7% of known roosts were lost: 14.5% due to forestry operations and 6.2% due to natural tree fall. Median colony size was 4.0 bats (IQR = 2.0–8.0) and declined during the study, probably because of locally high levels of roost loss. Post harvest colonies were smaller than colonies in areas that had not been harvested. Together, these results suggest the impact of clear-fell harvest on long-tailed bat populations is negative.

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Individuals' home ranges are constrained by resource distribution and density, population size, and energetic requirements. Consequently, home ranges and habitat selection may vary between individuals of different sex and reproductive conditions. Whilst home ranges of bats are well-studied in native habitats, they are often not well understood in modified landscapes, particularly exotic plantation forests. Although Chalinolobus tuberculatus (Vespertilionidae, Chiroptera) are present in plantation forests throughout New Zealand their home ranges have only been studied in native forest and forest-agricultural mosaic and no studies of habitat selection that included males had occurred in any habitat type. Therefore, we investigated C. tuberculatus home range and habitat selection within exotic plantation forest. Home range sizes did not differ between bats of different reproductive states. Bats selected home ranges with higher proportions of relatively old forest than was available. Males selected edges with open unplanted areas within their home ranges, which females avoided. We suggest males use these edges, highly profitable foraging areas with early evening peaks in invertebrate abundance, to maintain relatively low energetic demands. Females require longer periods of invertebrate activity to fulfil their needs so select older stands for foraging, where invertebrate activity is higher. These results highlight additional understanding gained when data are not pooled across sexes. Mitigation for harvest operations could include ensuring that areas suitable for foraging and roosting are located within a radius equal to the home range of this bat species.

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Environmental certification schemes have stimulated increasing interest in biodiversity and its management within exotic plantation forests. These schemes expect management to be scientifically-based, even though little is known about how often, or which, native species use exotic plantation forests. Greater knowledge of the ecology of native species within exotic plantation forests is required to advise management and reduce risks to native species, particularly those that are rare, such as the New Zealand long-tailed bat (Chalinolobus tuberculatus). Long-tailed bats use exotic plantation forests throughout New Zealand but need protection from the impacts of forest management, and particularly clear-fell harvest, that is achievable only through a better understanding of their biology. The consequences of the current reduced re-planting, and the conversion of plantation forests into pasture resulting in smaller forested areas, should not be ignored because they may be associated with reductions in long-tailed bat populations. We review the current knowledge of long-tailed bats' use of exotic plantation forests, and report for the first time which exotic plantations long-tailed bats are known to use. We make recommendations for the design of monitoring programmes to detect long-tailed bats within plantation forests, and for research into the effects of forest management, especially logging, and comment on the likely impacts of reductions in forested areas on long-tailed bats.