Estimating patterns of leaf herbivory along an altitudinal transect in NE Queensland rainforests: might global warming increase leaf herbivory in tropical rainforests?

Climate change has been taking place at unprecedented rates over the past decades. These fast alterations caused by human activities are leading to a global warming of the planet. Warmer temperatures are going to have important effects on vegetation and especially on tropical forests. Insects as well will be affected by climate change. This study tested the hypothesis that higher temperatures lead to a higher insect pressure on vegetation. Visual estimations of leaf damage were recorded and used to assess the extent of herbivory in nine 0.1ha plots along an altitudinal gradient, and therefore a temperature gradient. These estimations were made at both a community level and a species level, on 2 target species. Leaf toughness tests were performed on samples from the target species from each plot. Results showed a strong evidence of increasing insect damage along increasing temperature, with no significant effect from the leaf toughness.

Root and shoot attributes of indigenous perennial accessions of the wild mungbean (Vigna radiata ssp sublobata)

Root and shoot attributes of 12 indigenous perennial accessions of the wild mungbean (Vigna radiata ssp. sublobata) were evaluated in early and late summer sowings in the field in SE Queensland. All but one of the accessions were obtained from the Townsville-Charters Towers region of NE Queensland. In both sowings, the accessions developed thickened tap and lateral roots, the taproot thickening extending to a depth of 0.20-0.30m below the soil surface, depending on accession. The thickened lateral roots emerged from the taproot within 0.10m of the soil surface, and extended laterally up to 1.10 m, remaining close to the soil surface. Differences among the accessions in gross root morphology and phenology were relatively small. There were differences among the accessions in the production of seed, tuberised root, and recovered total plant biomass. Depending on accession and sowing date, the tuberised roots accounted for up to 31% of recovered plant biomass and among accessions, the root biomass was positively correlated with total plant biomass. In contrast, seed biomass represented only a small proportion of recovered plant biomass, up to a maximum of 14%, depending on accession and sowing date. Among accessions, the proportion of seed biomass tended to be negatively correlated with that of tuber biomass. The perennial trait appears to be unique to Australian accessions of wild mungbean obtained from coastal-subcoastal, speargrass-dominant woodlands of NE Queensland. Although the ecological significance of the trait remains conjectural, field observation indicates that it facilitates rapid plant re-growth following early summer rainfall, especially where dry-season. re has removed previous-season above-ground growth.

Development of a genetic method to estimate effective spawner numbers in the NPF and Queensland tiger prawn fisheries

OBJECTIVES: 1. To critically evaluate a variety of mathematical methods of calculating effective population size (Ne) by conducting comprehensive computer simulations and by analysis of empirical data collected from the Moreton Bay population of tiger prawns. 2. To lay the groundwork for the application of the technology in the NPF. 3. To produce software for the calculation of Ne, and to make it widely available.

A synthesis of dominant ecological processes in intensive shrimp ponds and adjacent coastal environments in NE Australia

One of the key environmental concerns about shrimp farming is the discharge of waters with high levels of nutrients and suspended solids into adjacent waterways. In this paper we synthesize the results of our multidisciplinary research linking ecological processes in intensive shrimp ponds with their downstream impacts in tidal, mangrove-lined creeks. The incorporation of process measurements and bioindicators, in addition to water quality measurements, improved our understanding of the effect of shrimp farm discharges on the ecological health of the receiving water bodies. Changes in water quality parameters were an oversimplification of the ecological effects of water discharges, and use of key measures including primary production rates, phytoplankton responses to nutrients, community shifts in zooplankton and delta(15)N ratios in marine plants have the potential to provide more integrated and robust measures. Ultimately, reduction in nutrient discharges is most likely to ensure the future sustainability of the industry. (C) 2003 Elsevier Ltd. All rights reserved.

Herbicides implicated as the cause of severe mangrove dieback in the Mackay region, NE Australia: consequences for marine plant habitats of the GBR World Heritage Area

Herbicides, particularly diuron, were correlated with severe and widespread dieback of the dominant mangrove, Avicennia marina (Forsk.) Vieth. var. eucalyptifolia (Val.) N.C. Duke (Avicenniaceae), its reduced canopy condition, and declines in seedling health within three neighbouring estuaries in the Mackay region of NE Australia. This unusual species-specific dieback, first observed in the early 1990s, had gotten notably worse by 2002 to affect > 30km(2) of mangroves in at least five adjacent estuaries in the region. Over the past century, agricultural production has responded well to the demands of increasing population with improvements in farm efficiency assisted by significant increases in the use of agricultural chemicals. However, with regular and episodic river flow events, these chemicals have sometimes found their way into estuarine and nearshore water and sediments where their effects on marine habitats have been largely unquantified. Investigations over the last three years in the Mackay region provide compelling evidence of diuron, and possibly other agricultural herbicides, as the most likely cause of the severe and widespread mangrove dieback. The likely consequences of such dieback included declines in coastal water quality with increased turbidity, nutrients and sediment deposition, as well as further dispersal of the toxic chemicals. The implications of such findings are immense since they describe not only the serious deterioration of protected and beneficial mangrove habitat but also the potential for significant direct and indirect effects on other highly-valued estuarine and marine habitats in the region, including seagrass beds and coral reefs of the Great Barrier Reef lagoon. This article reviews all key findings and observations to date and describes the essential correlative and causative evidence. (c) 2004 Elsevier Ltd. All rights reserved.

Prevalence, severity, and heritability of Stephanofilaria lesions on cattle in central and southern Queensland, Australia

Observations of cattle in central and southern Queensland are collated to de. ne the prevalence and area of Stephanofilaria lesions associated with infestations of the buffalo fly, Haematobia irritans exigua. The observations were made on herds that were being used for other purposes. In a survey of similar to 1500 animals at Belmont in central Queensland in 1982, 98% of cows and 70% of calves had lesions. Most lesions were on the neck and dewlap and 10% were raw and weeping at the time of sampling. The total area of lesions per animal was strongly related to cattle breed and age. Old Bos taurus animals had the greatest area of lesions, whereas young Bos indicus had the least. Heritability estimates were low, averaging 0.01 for calves and 0.18 for cows. A smaller survey of cows and steers at Craighoyle in central Queensland in 1986 showed a higher numbers of lesions and positive correlations between the total lesion area and animal size. The lesion area increased with tick survival, suggesting that tick-resistant animals are also resistant to Stephanofilaria infection. Steers had smaller areas of lesions than cows, as found previously with cattle ticks. Long-term monitoring observations in central and southern Queensland between 1981 and 1986 showed that the total area of lesions was seasonal with a peak in late summer, consistent with the seasonal incidence of buffalo fly. Animals segregated into Low and High lesion herds maintained their differences over time. The lesions penetrated the dermis of the cattle hides and rendered the affected area unusable, but few lesions occurred on valuable parts of the hide so such economic effects are likely to be insignificant. One animal nearly died of a haemorrhage from a lesion on the dewlap and had to be treated. The results can inform policy on buffalo fly control, and biosecurity preparations in relation to the potential establishment of the OldWorld screw-worm fly, Chrysomyia bezziana, in Australia, which will be facilitated by the lesions. The results emphasise the significant animal welfare and biosecurity risks posed by the lesions in northern Australia.

Photophysical studies and in vitro skin permeation/retention of Foscan (R)/nanoemulsion (NE) applicable to photodynamic therapy skin cancer treatment.

In this work we evaluated the photophysical and in vitro properties of Foscan (R), a second-generation photosensitizer drug (PS) widely used in systemic clinical protocols for cancer therapy based on Photodynamic Therapy (PDT). We employed biodegradable nanoemulsions (NE) as a colloidal vehicle of the oil/water (o/w) type focusing in topical administration of Foscan (R) and other photosensitizer drugs. This formulation was obtained and stabilized by the methodology described by Tabosa do Egito et al.,(30) based on the mixture of two phases: an aqueous solution and an organic medium consisting of nonionic surfactants and oil. The photodynamic potential of the drug incorporated into the NE was studied by steady-state and time-resolved spectroscopic techniques. We also analyzed the in vitro biological behavior carried out in mimetic biological environment protocols based on the animal model. After topical application in a skin animal model, we evaluated the Foscan (R)/NE diffusion flux into the skin layers (stratum corneum and epidermis + dermis) by classical procedures using Franz Diffusion cells. Our results showed that the photophysical properties of PS were maintained after its incorporation into the NE when compared with homogeneous organic medium. The in vitro assays enabled the determination of an adequate profile for the interaction of this system in the different skin layers, with an ideal time lag of 6 h after topical administration in the skin model. The Foscan (R) diffusion flux (J) was increased when this PS was incorporated into the NE, if compared with its flux in physiological medium. These parameters demonstrated that the NE can be potentially applied as a drug delivery system (DDS) for Foscan (R) in both in vitro and in vivo assays, as well as in future clinical applications involving topical skin cancer PDT.

Northern wing, General Purpose North 3, University of Queensland, St Lucia

As seen from Blair Road.

Northern wing, General Purpose North 3, University of Queensland, St Lucia

As seen from Balir Road.

West elevation, General Purpose North 3, University of Queensland, St Lucia

Formal elevation facing University of Queensland entrance roads.

Eastern edge, General Purpose North 3, University of Queensland, St Lucia

As seen from informal courtyard; Duhig Tower beyond.

West elevation, General Purpose North 3, University of Queensland, St Lucia

Formal elevation facing University of Queensland entrance roads.

West elevation, General Purpose North 3, University of Queensland, St Lucia

Formal elevation facing University of Queensland entrance roads.