Mapping and characterising subtropical estuarine landscapes using aerial photography and GIS for potential application in wildlife conservation and management

Coarse-resolution thematic maps derived from remotely sensed data and implemented in GIS play an important role in coastal and marine conservation, research and management. Here, we describe an approach for fine-resolution mapping of land-cover types using aerial photography and ancillary GIs and ground data in a large (100 x 35 km) subtropical estuarine system (Moreton Bay, Queensland, Australia). We have developed and implemented a classification scheme representing 24 coastal (subtidal, intertidal. mangrove, supratidal and terrestrial) cover types relevant to the ecology of estuarine animals, nekton and shorebirds. The accuracy of classifications of the intertidal and subtidal cover types, as indicated by the agreement between the mapped (predicted) and reference (ground) data, was 77-88%, depending on the zone and level of generalization required. The variability and spatial distribution of habitat mosaics (landscape types) across the mapped environment were assessed using K-means clustering and validated with Classification and Regression Tree models. Seven broad landscape types could be distinguished and ways of incorporating the information on landscape composition into site-specific conservation and field research are discussed. This research illustrates the importance and potential applications of fine-resolution mapping for conservation and management of estuarine habitats and their terrestrial and aquatic wildlife. (c) 2005 Elsevier Ltd. All rights reserved.

Idiopathic necrotizing dermatitis: Current management

Objectives: To identify and demonstrate necrotizing dermatitis in infancy; an uncommon, puzzling syndrome, in which anecdotal reporting and personal experience indicates that one third of cases may require skin grafting. Much informed discussion about the pathogenesis of this distressing syndrome centres on the role of spider envenomation; and in particular on the speculative role of the Australian White-tailed spider, Lampona cylindrata. Methods: We present here six cases of necrotizing dermatitis treated surgically at the Royal Children's Hospital and Mater Children's Hospital in Brisbane over the period from 1991 to 1999. Clinical history, surgical details and pathological investigations were reviewed in each case. Microbiological investigation of necrotic ulcers included standard aerobic and anaerobic culture. Result: Nocardia and Staphylococcus were cultured in two cases, but no positive bites were witnessed and no spiders were identified by either the children or their parents. All cases were treated with silver sulphadiazine creme. Two of the infants required general anaesthesia, excision debridement and split skin grafting. The White-tailed spider, Lampona cylindrata, does not occur in Queensland, but Lampona murina does; neither species has necrotizing components in its venom. Circumstantial evidence is consistent with this syndrome being due to invertebrate envenomation, possibly following arachnid bites. Conclusion: In our experience there is insufficient evidence to impute a specific genus as the cause, at this stage of scientific knowledge. If the offending creature is a spider, we calculate that the syndrome of necrotizing dermatitis occurs in less than 1 in 5000 spider bites.

Boron nutrition and chilling tolerance of warm climate crop species

Background Field observations and glasshouse studies have suggested links between boron (B)-deficiency and leaf damage induced by low temperature in crop plants, but causal relationships between these two stresses at physiological, biochemical and molecular levels have yet to be explored. Limited evidence at the whole-plant level suggests that chilling temperature in the root zone restricts B uptake capacity and/or B distribution/utilization efficiency in the shoot, but the nature of this interaction depends on chilling tolerance of species concerned, the mode of low temperature treatment (abrupt versus gradual temperature decline) and growth conditions (e.g. photon flux density and relative humidity) that may exacerbate chilling stress. Scope This review explores roles of B nutrition in chilling tolerance of continual root or transient shoot chills in crop species adapted to warm season conditions. It reviews current research on combined effects of chilling temperature (ranging from > 0 to 20 degrees C) and B deficiency on growth and B nutrition responses in crop species differing in chilling tolerance. Conclusion For subtropical/tropical species (e.g. cucumber, cassava, sunflower), root chilling at 10-17 degrees C decreases B uptake efficiency and B utilization in the shoot and increases the shoot : root ratio, but chilling-tolerant temperate species (e.g. oilseed rape, wheat) require much lower root chill temperatures (2-5 degrees C) to achieve the same responses. Boron deficiency exacerbates chilling injuries in leaf tissues, particularly under high photon flux density. Suggested mechanisms for B x chilling interactions in plants are: (a) chilling-induced reduction in plasmalemma hydraulic conductivity, membrane fluidity, water channel activity and root pressure, which contribute to the decrease in root hydraulic conductance, water uptake and associated B uptake; (b) chilling-induced stomatal dysfunction affecting B transport from root to shoot and B partitioning in the shoot; and (c) B deficiency induced sensitivity to photo-oxidative damage in leaf cells. However, specific evidence for each of the mechanisms is still lacking. Impacts of B status on chilling tolerance in crop species have important implications for the management of B supply during sensitive stages of growth, such as early growth after planting and early reproductive development, both of which can coincide with the occurrence of chilling temperatures in the field.

An identification tool for the Australian weedy Sporobolus species based on random amplified polymorphic DNA (RAPD) profiles

Based on morphological features alone, there is considerable difficulty in identifying the 5 most economically damaging weed species of Sporobolus [ viz. S. pyramidalis P. Beauv., S. natalensis ( Steud.) Dur and Schinz, S. fertilis ( Steud.) Clayton, S. africanus (Poir.) Robyns and Tourney, and S. jacquemontii Kunth.] found in Australia. A polymerase chain reaction (PCR)-based random amplified polymorphic DNA ( RAPD) technique was used to create a series of genetic markers that could positively identify the 5 major weeds from the other less damaging weedy and native Sporobolus species. In the initial RAPD pro. ling experiment, using arbitrarily selected primers and involving 12 species of Sporobolus, 12 genetic markers were found that, when used in combination, could consistently identify the 5 weedy species from all others. Of these 12 markers, the most diagnostic were UBC51(490) for S. pyramidalis and S. natalensis; UBC43(310,2000,2100) for S. fertilis and S. africanus; and OPA20(850) and UBC43(470) for S. jacquemontii. Species-specific markers could be found only for S. jacquemontii. In an effort to understand why there was difficulty in obtaining species-specific markers for some of the weedy species, a RAPD data matrix was created using 40 RAPD products. These 40 products amplified by 6 random primers from 45 individuals belonging to 12 species, were then subjected to numerical taxonomy and multivariate system (NTSYS pc version 1.70) analysis. The RAPD similarity matrix generated from the analysis indicated that S. pyramidalis was genetically more similar to S. natalensis than to other species of the 'S. indicus complex'. Similarly, S. jacquemontii was more similar to S. pyramidalis, and S. fertilis was more similar to S. africanus than to other species of the complex. Sporobolus pyramidalis, S. jacquemontii, S. africanus, and S. creber exhibited a low within-species genetic diversity, whereas high genetic diversity was observed within S. natalensis, S. fertilis, S. sessilis, S. elongates, and S. laxus. Cluster analysis placed all of the introduced species ( major and minor weedy species) into one major cluster, with S. pyramidalis and S. natalensis in one distinct subcluster and S. fertilis and S. africanus in another. The native species formed separate clusters in the phenograms. The close genetic similarity of S. pyramidalis to S. natalensis, and S. fertilis to S. africanus may explain the difficulty in obtaining RAPD species-specific markers. The importance of these results will be within the Australian dairy and beef industries and will aid in the development of integrated management strategy for these weeds.

Genetic diversity and regional identity in the Australian remnant Nothofagus moorei

Nothofagus moorei (F. Muell.) Krasser has a disjunct and narrow distribution in south-eastern Australian cool temperate rainforest. To assess the conservation-genetic priorities for this species, the genetic diversity of 20 populations sampled from the largest remnant patches at northern and southern distributional extremes, the McPherson and Barrington ranges (a total of 146 individuals), was investigated by using inter simple sequence repeats (ISSR). Regeneration in northern regions of N. moorei has been documented to be predominantly by vegetative means, but our results indicate little evidence of clonality outside the multi-stemmed rings of trees. In addition, genetic diversity was considerably higher in the northern (McPherson, h = 0.1613) than in the southern range (Barrington, h = 0.1159), and genetic differentiation was significantly positively correlated with geographic distance in the former region, but not the latter. Total intraspecific variation was moderate, as measured by Shannon's diversity index, I = 0.2719, and Nei's gene diversity, h = 0.1672, and is considered at the high end of spectrum for estimates of narrow endemic species. An analysis of molecular variation indicated that the majority of genetic variation is partitioned among individuals within population (60%; P < 0.001), rather than among populations within regions (10%; P < 0.001). However, a large and significant component of the measured diversity was partitioned between northern and southern regions (29%; P < 0.001). Several hypotheses are outlined to explain these differences and management implications are discussed. However, given the narrow range, poor dispersal mechanism and restriction to cool temperate rainforest, the continued existence of N. moorei is most threatened by environmental instability and habitat loss resulting from global climate change. In this context the northern regions of the species are most at risk and extinction of such populations would lead to a significant loss of genetic variation for the species as a whole.

Development of a DNA-based method for detection and identification of Phytophthora species

Phytophthora diseases cause major losses to agricultural and horticultural production in Australia and worldwide. Most Phytophthora diseases are soilborne and difficult to control, making disease prevention an important component of many disease management strategies. Detection and identification of the causal agent, therefore, is an essential part of effective disease management. This paper describes the development and validation of a DNA-based diagnostic assay that can detect and identify 27 different Phytophthora species. We have designed PCR primers that are specific to the genus Phytophthora. The resulting amplicon after PCR is subjected to digestion by restriction enzymes to yield a specific restriction pattern or fingerprint unique to each species. The restriction patterns are compared with a key comprising restriction patterns of type specimens or representative isolates of 27 different Phytophthora species. A number of fundamental issues, such as genetic diversity within and among species which underpin the development and validation of DNA-based diagnostic assays, are addressed in this paper.

Ecological-economic modeling for biodiversity management: Potential, pitfalls, and prospects

Ecologists and economists both use models to help develop strategies for biodiversity management. The practical use of disciplinary models, however, can be limited because ecological models tend not to address the socioeconomic dimension of biodiversity management, whereas economic models tend to neglect the ecological dimension. Given these shortcomings of disciplinary models, there is a necessity to combine ecological and economic knowledge into ecological-economic models. It is insufficient if scientists work separately in their own disciplines and combine their knowledge only when it comes to formulating management recommendations. Such an approach does not capture feedback loops between the ecological and the socioeconomic systems. Furthermore, each discipline poses the management problem in its own way and comes up with its own most appropriate solution. These disciplinary solutions, however are likely to be so different that a combined solution considering aspects of both disciplines cannot be found. Preconditions for a successful model-based integration of ecology and economics include (1) an in-depth knowledge of the two disciplines, (2) the adequate identification and framing of the problem to be investigated, and (3) a common understanding between economists and ecologists of modeling and scale. To further advance ecological-economic modeling the development of common benchmarks, quality controls, and refereeing standards for ecological-economic models is desirable.

Objectives for multiple-species conservation planning

The first step in conservation planning is to identify objectives. Most stated objectives for conservation, such as to maximize biodiversity outcomes, are too vague to be useful within a decision-making framework. One way to clarify the issue is to define objectives in terms of the risk of extinction for multiple species. Although the assessment of extinction risk for single species is common, few researchers have formulated an objective function that combines the extinction risks of multiple species. We sought to translate the broad goal of maximizing the viability of species into explicit objectives for use in a decision-theoretic approach to conservation planning. We formulated several objective functions based on extinction risk across many species and illustrated the differences between these objectives with simple examples. Each objective function was the mathematical representation of an approach to conservation and emphasized different levels of threat Our objectives included minimizing the joint probability of one or more extinctions, minimizing the expected number of extinctions, and minimizing the increase in risk of extinction from the best-case scenario. With objective functions based on joint probabilities of extinction across species, any correlations in extinction probabilities bad to be known or the resultant decisions were potentially misleading. Additive objectives, such as the expected number of extinctions, did not produce the same anomalies. We demonstrated that the choice of objective function is central to the decision-making process because alternative objective functions can lead to a different ranking of management options. Therefore, decision makers need to think carefully in selecting and defining their conservation goals.

Tradeoffs of different types of species occurrence data for use in systematic conservation planning

Data on the occurrence of species are widely used to inform the design of reserve networks. These data contain commission errors (when a species is mistakenly thought to be present) and omission errors (when a species is mistakenly thought to be absent), and the rates of the two types of error are inversely related. Point locality data can minimize commission errors, but those obtained from museum collections are generally sparse, suffer from substantial spatial bias and contain large omission errors. Geographic ranges generate large commission errors because they assume homogenous species distributions. Predicted distribution data make explicit inferences on species occurrence and their commission and omission errors depend on model structure, on the omission of variables that determine species distribution and on data resolution. Omission errors lead to identifying networks of areas for conservation action that are smaller than required and centred on known species occurrences, thus affecting the comprehensiveness, representativeness and efficiency of selected areas. Commission errors lead to selecting areas not relevant to conservation, thus affecting the representativeness and adequacy of reserve networks. Conservation plans should include an estimation of commission and omission errors in underlying species data and explicitly use this information to influence conservation planning outcomes.

Why are there so few genetic markers available for coral population analyses?

Coral reefs are in serious decline, and research in support of reef management objectives is urgently needed. Reef connectivity analyses have been highlighted as one of the major future research avenues necessary for implementing effective management initiatives for coral reefs. Despite the number of new molecular genetic tools and the wealth of information that is now available for population-level processes in many marine disciplines, scleractinian coral population genetic information remains surprisingly limited. Here we examine the technical problems and approaches used, address the reasons contributing to this delay in understanding, and discuss the future of coral population marker development. Considerable resources are needed to target the immediate development of an array of relevant genetic markers coupled with the rapid production of management focused data in order to help conserve our globally threatened coral reef resources.

Candidatus "Anammoxoglobus propionicus" a new propionate oxidizing species of anaerobic ammonium oxidizing bacteria

The bacteria that mediate the anaerobic oxidation of ammonium (anammox) are detected worldwide in natural and man-made ecosystems, and contribute up to 50% to the loss of inorganic nitrogen in the oceans. Two different anammox species rarely live in a single habitat, suggesting that each species has a defined but yet unknown niche. Here we describe a new anaerobic ammonium oxidizing bacterium with a defined niche: the co-oxidation of propionate and ammonium. The new anammox species was enriched in a laboratory scale bioreactor in the presence of ammonium and propionate. Interestingly, this particular anammox species could out-compete other anammox bacteria and heterotrophic denitrifiers for the oxidation of propionate in the presence of ammonium, nitrite and nitrate. We provisionally named the new species Candidatus "Anammoxoglobus propionicus".

The effects of temperature and salinity on Acacia harpophylla (brigalow) (Mimosaceae) germination

Acacia harpophylla F. Muell. (brigalow) used to naturally occur over a range of about 50 000 km(2) in Queensland and New South Wales, Australia. Large scale clearing for agriculture has reduced the area to less than 20 000 km(2) and it is estimated that 20-25% of vertebrate fauna living in brigalow communities will become locally extinct as a result of the current clearing induced loss of habitat. Some coal mining companies in central Queensland have become interested in providing habitat for the endangered bridle nail-tailed wallaby that lives in brigalow vegetation. However, there is little known about establishment techniques for brigalow on mine sites and other disturbed ground; an understanding of brigalow biology and ecology is required to assist in the conservation of this threatened vegetation community and for re-creation of bridled nail-tail wallaby habitat in the post mining landscape. Brigalow is an unusual species of Acacia because it is not hard-seeded and germinates readily without the need to break seed-coat imposed dormancy. Germination trials were undertaken to test the ability of brigalow seed to germinate with a range of temperatures and salinity levels similar to those experienced in coal mine spoil. Optimum germination was found to occur at temperatures from 15 to 38 degrees C and no germination was recorded at 45 degrees C. Brigalow was very tolerant of high salt levels and germinated at percentages greater than 50% up to the highest salinity tested, 30 dS/m. Germination of greater than 90% occurred up to an electrical conductivity of 20 dS/m. The results indicate brigalow seed can be sown in summer when rains are most likely to occur, however, shading of the seed with extra soil or mulch may ensure the ground surface does not become too hot for germination. Because of its ability to germinate at high salinity levels, brigalow may be suitable for use in saline mine wastes which are common on sites to be rehabilitated after mining.

Responses of four Australian tree species to toxic concentrations of copper in solution culture

In Australia, metal-contaminated sites, including those with elevated levels of copper (Cu), are frequently revegetated with endemic plants. Little is known about the responses of Australian plants to excess Cu. Acacia holosericea, Eucalyptus crebra, Eucalyptus camaldulensis, and Melaleuca leucadendra were grown in solution culture with six Cu treatments (0.1 to 40 mu M). While A. holosericea was the most tolerant to excess Cu, all of the species tested were sensitive to excess Cu when compared with exotic tree and agricultural species. The critical external concentrations for toxicity were < 0.7 mu M for all species tested. There was little differentiation between shoot-tissue Cu concentrations in normal versus treated plants, thus, the derivation of critical shoot concentrations was possible only for the most tolerant species, A. holosericea. Critical root Cu concentrations were approximately 210 mu g g(-1) (A. holosericea), 150 mu g g(-1) (E. crebra), 25 mu g g(-1) (E. camaldulensis), and 165 mu g g(-1) (M. leucadendra). These results provide the first comprehensive combination of growth responses, critical concentrations, and toxicity symptoms for three important Australian genera for use in the management of Cu-contaminated sites.

Mapping structural parameters and species composition of riparian vegetation using IKONOS and Landsat ETM+ data in Australian tropical savannahs

Government agencies responsible for riparian environments are assessing the utility of remote sensing for mapping and monitoring vegetation structural parameters. The objective of this work was to evaluate Ikonos and Landsat-7 ETM+ imagery for mapping structural parameters and species composition of riparian vegetation in Australian tropical savannahs for a section of Keelbottom Creek, Queensland, Australia. Vegetation indices and image texture from Ikonos data were used for estimating leaf area index (R-2 = 0.13) and canopy percentage foliage cover (R-2 = 0.86). Pan-sharpened Ikonos data were used to map riparian species composition (overall accuracy = 55 percent) and riparian zone width (accuracy within +/- 3 m). Tree crowns could not be automatically delineated due to the lack of contrast between canopies and adjacent grass cover. The ETM+ imagery was suited for mapping the extent of riparian zones. Results presented demonstrate the capabilities of high and moderate spatial resolution imagery for mapping properties of riparian zones.