Appraisal of random and systematic land cover transitions for regional water balance and revegetation strategies

This study describes the use of landscape transition analysis as a means for effective basin management. Land cover transitions from 1995 to 2002 were analyzed using a cross-tabulation matrix for an important economic zone in south-west Victoria, Australia. Specifically, the matrix was used to determine whether the transitions were random or systematic. Random landscape transitions occur when a land cover replaces other land covers in proportion to their availability. Systematic landscape transitions occur when there are deviations from random patterns, and land use types ‘target’ other land use types for replacement. The analysis was conducted with 11 land cover categories and showed that dryland pastures have been systematically losing area to dryland crops and blue gum (Eucalyptus globulus) plantations. Dryland crops have systematically expanded in the north-east of the catchment, an area where increasing in-stream salinization has occurred concurrently with this transition. The systematic expansion of the blue gum plantations has been predominantly in the south-west of the catchment and has the potential to reduce stream flows and groundwater recharge in an already water-stressed region, as blue gums use more water than the dryland pastures they are replacing. All other transitions were largely random. These findings have implications for land use planning in the study area for regional water balance and revegetation strategies. Landscape transition analysis is a cost-effective means of contributing to the management of water resources at a regional scale, and is highly recommended for future basin planning.

Photodegradation, interaction with iron oxides and bioavailability of dissolved organic matter from forested floodplain sources

Photochemical degradation of dissolved organic matter (DOM) can influence food webs by altering the availability of carbon to microbial communities, and may be particularly important following periods of high DOM input (e.g. flooding of forested floodplains). Iron oxides can facilitate these reactions, but their influence on subsequent organic products is poorly understood. Degradation experiments with billabong (= oxbow lake) water and river red gum (Eucalyptus camaldulensis) leaf leachate were conducted to assess the importance of these reactions in floodplain systems. Photochemical degradation of DOM in sunlight-irradiated quartz tubes (with and without amorphous iron oxide) was studied using gas chromatography and UV-visible spectroscopy. Photochemical reactions generated gaseous products and small organic acids. Bioavailability of billabong DOM increased following irradiation, whereas that of leaf leachate was not significantly altered. Fluorescence excitation-emission spectra suggested that the humic component of billabong organic matter was particularly susceptible to degradation, and the source of DOM influenced the changes observed. The addition of amorphous iron oxide increased rates of photochemical degradation of leachate and billabong DOM. The importance of photochemical reactions to aquatic systems will depend on the source of the DOM and its starting bioavailability, whereas inputs of freshly formed iron oxides will accelerate the processes.

Taking environmental water requirements and climate change into account in the designation and management of protected areas for floodplain ecosystems

In 2005, the Victorian government asked the Victorian Environmental Assessment Council (VEAC) to 1) identify and evaluate the extent, condition, values, management, resources and uses of riverine red gum forests and associated fauna, wetlands, floodplain ecosystems and vegetation communities in northern Victoria; and 2) make recommendations relating to the conservation, protection and ecological sustainable use of public land. The design of a comprehensive, adequate and representative (CAR) reserve system was a key part of the recommendations made by VEAC. In order to assist in the decision-making for environmental water allocation for protected areas and other public land, a process for identifying flood-dependent natural values on the Victorian floodplains of the River Murray and its tributaries was developed.

Although some areas such as the Barmah forest are very well known, there have been few comprehensive inventories of important natural values along the Murray floodplains. For this project, VEAC sought out and compiled data on flood requirements (natural flood frequency, critical interval between floods, minimum duration of floods) for all flood-dependent ecological vegetation classes (EVCs) and threatened species along the Goulburn, Ovens, King and Murray Rivers in Victoria. The project did not include the Kerang Lakes and floodplains of the Avoca, Loddon and Campaspe Rivers. 186 threatened species and 110 EVCs (covering 224,247 ha) were identified as flood-dependent and therefore at risk from insufficient flooding.

Past environmental water allocations have targeted a variety of different natural assets (e.g. stressed red gum trees, colonial nesting waterbirds, various fish species), but consideration of the water requirements of the full suite of floodplain ecosystems and significant species has been limited. By considering the water requirements of the full range of natural assets, the effectiveness of water delivery for biodiversity can be maximised. This approach highlights the species and ecosystems most in need of water and builds on the icon sites approach to view the Murray floodplains as an interconnected system. This project also identified for the first time the flood-frequency and duration requirements for the full suite of floodplain ecosystems and significant species.

This project is the most comprehensive identification of water requirements for natural values on the floodplain to date, and is able to be used immediately to guide prioritisation of environmental watering. As more information on floodplain EVCs and species becomes available, the water requirements and distribution of values can be refined by ecologists and land and water managers. That is, the project is intended as the start of an adaptive process allowing for the incorporation of monitoring and feedback over time. The project makes it possible to transparently and easily communicate the extent to which manipulated or natural flows benefit various natural values. Quantitative and visual outputs such as maps will enable environmental managers and the public to easily see which values do and do not receive water (see http://www.veac.vic.gov.au/riverredgumfinal.htm for further details).

Estimation of in vitro prebiotic activity of individual and mixed dietary fibres

Background: Epidemiological studies have demonstrated a link between dietary fibre deficiency and prevalence of many “Western diseases” particularly colon related diseases. Many of the health benefits associated with dietary fibre are attributed to their prebiotic effect. However, not all fibres have the same prebiotic potential or the same impact on colon health.

Objective: To examine the in vitro fermentation properties of individual and mixed dietary fibres by measuring fermentation byproducts over time.

Design: Wheat bran and guar gum were selected for this study. Individual and mixed dietary fibres were added to batch fermentation system and were inoculated with fresh faecal inoculum (n= 4). Positive (inulin) and negative (no substrate) fermenters were also used to determine the differences. The pH of the five fermenters was adjusted to a baseline of 5.5 and 6.8 representing the pH of the proximal and distal sections of the colon respectively. Samples were drawn out of the fermenters at 0, 3, 9 and 24 hours for the analysis of pH, ammonia and short chain fatty acids (SCFAs).

Outcomes: There were no significant differences in the pH levels at various time points between fermenters adjusted to pH 5.5 at baseline. However, in fermenters adjusted to pH 6.8 the pH of the fermenter containing wheat bran increased over the time (24h (P = 0.017)) due to production of a high amount of ammonia. The total SCFAs production was greater in fermenters containing combined fibres.

Conclusion: There is a large inter-individual variation in the prebiotic effect of all types of dietary fibres, however, in the present study, dietary fibre combinations showed greater prebiotic potential compared with the individual fibres.

Studies on dietary fibre : analysis, epidemiological and physiological aspects

This thesis involves an investigation in three areas; first, a study of an enzymatic-gravimetric method for the analysis of dietary fibre; second, a survey of dietary fibre intake in an area of a developing country, and finally, some observations on the functional aspects of gel-forming dietary fibre in the rat. A simple and rapid enzymatic-gravimetric assay for both soluble and insoluble dietary fibre has been critically investigated. Reference samples were also analysed by a more comprehensive, enzymatic gas chromatographic method to allow testing of the relative accuracy of the enzymatic-gravimetric method. The enzymatic-gravimetric method was found to be highly reproducible but gave a slightly higher value for total dietary fibre than the more comprehensive method. This discrepancy is probably due to the presence of small quantities of resistant starch and protein residue which are recovered in the enzymatic-gravimetric method. In the enzymatic-gas chromatographic method, protein residue is not measured, and resistant starch is estimated, but not counted as dietary fibre. The enzymatic-gravimetric method was applied to the analysis of foods commonly consumed in the Padang region of West Sumatra in Indonesia, in order to estimate dietary fibre intake in the region. Daily intakes of usual foods were estimated by use of a 24-hour recall procedure aided by food photographs to assist in the estimation of portion size. Samples of approximately 60 of the most commonly consumed foods were collected and analysed for dietary fibre. These appear to be the first data which report values for dietary fibre in Indonesion foods and they represent a significant improvement upon the existing data on crude fibre content. Knowledge of the amounts of foods usually consumed and their dietary fibre content allowed an estimation of usual intakes of dietary fibre. Fibre intake was found to be lower than in the developing countries of Africa and was comparable to intakes measured in the U.K. This is the first study to show that in this part of South East Asia, a developing country area using polished rice as a staple food, dietary fibre intakes are as low as in Western countries. Low intakes of fibre are believed to be related to the prevalence of a range of diseases and, in this study, preliminary data on the rates of non-infective, chronic diseases were collected from the two main hospitals in West Sumatra. Chronic, non-infectious diseases such as inguinal hernia, appendicitis, haemorrhoids, diabetes mellitus, hypertension and malignant neoplasms of the rectum are relatively frequent in West Sumatra. While no firm conclusions can be drawn from these data, they do show the possibility of a relationship between low intakes of dietary fibre and the prevalence of these diseases, and suggest that further investigation is necessary. Some observations were made of the effect of gel-forming dietary fibre on stomach emptying and intestinal transit rate in the rat. Xanthan gum was added to iso-osmotic solutions to produce increased viscosity and phenol sulphonphthalein (phenol red) was used as a non-absorbable marker. Gavage feeding of solutions with a range of viscosities was used to study the effect of viscosity on the rate of stomach emptying and intestinal transit. Increased viscosity was observed to slow gastro-intestinal transit and this provides one mechanism by which dietary fibre of the gel-forming type ray improve glucose tolerance.

Flowering ecology of a Box-Ironbark Eucalyptus community

Box-Ironbark forests occur on the inland hills of the Great Dividing Range in Australia, from western Victoria to southern Queensland. These dry, open forests are characteristically dominated by Eucalyptus species such as Red Ironbark E. tricarpa, Mugga Ironbark E. sideroxylon and Grey Box E. microcarpa. Within these forests, several Eucalyptus species are a major source of nectar for the blossom-feeding birds and marsupials that form a distinctive component of the fauna. In Victoria, approximately 83% of the original pre - European forests of the Box-Ironbark region have been cleared, and the remaining fragmented forests have been heavily exploited for gold and timber. This exploitation has lead to a change in the structure of these forests, from one dominated by large 80-100 cm diameter, widely -spaced trees to mostly small (≥40 cm DBH), more densely - spaced trees. This thesis examines the flowering ecology of seven Eucalyptus species within a Box-Ironbark community. These species are characteristic of Victorian Box-Ironbark forests; River Red Gum E. camaldulensis, Yellow Gum E. leucoxylon, Red Stringybark E. macrorhyncha, Yellow Box E. melliodora, Grey Box E. microcarpa, Red Box E. polyanthemos and Red Ironbark E. tricarpa. Specifically, the topics examined in this thesis are: (1) the floral character traits of species, and the extent to which these traits can be associated with syndromes of bird or insect pollination; (2) the timing, frequency, duration, intensity, and synchrony of flowering of populations and individual trees; (3) the factors that may explain variation in flowering patterns of individual trees through examination of the relationships between flowering and tree-specific factors of individually marked trees; (4) the influence of tree size on the flowering patterns of individually marked trees, and (5) the spatial and temporal distribution of the floral resources of a dominant species, E. tricarpa. The results are discussed in relation to the evolutionary processes that may have lead to the flowering patterns, and the likely effects of these flowering patterns on blossom-feeding fauna of the Box-Ironbark region. Flowering observations were made for approximately 100 individually marked trees for each species (a total of 754 trees). The flower cover of each tree was assessed at a mean interval of 22 (+ 0.6) days for three years; 1997, 1998 and 1999. The seven species of eucalypt each had characteristic flowering seasons, the timing of which was similar each year. In particular, the timing of peak flowering intensity was consistent between years. Other spatial and temporal aspects of flowering patterns for each species, including the percentage of trees that flowered, frequency of flowering, intensity of flowering and duration of flowering, displayed significant variation between years, between forest stands (sites) and between individual trees within sites. All seven species displayed similar trends in flowering phenology over the study, such that 1997 was a relatively 'poor' flowering year, 1998 a 'good' year and 1999 an 'average' year in this study area. The floral character traits and flowering seasons of the seven Eucalyptus species suggest that each species has traits that can be broadly associated with particular pollinator types. Differences between species in floral traits were most apparent between 'summer' and 'winter' flowering species. Winter - flowering species displayed pollination syndromes associated with bird pollination and summer -flowering species displayed syndromes more associated with insect pollination. Winter - flowering E. tricarpa and E. leucoxylon flowers, for example, were significantly larger, and contained significantly greater volumes of nectar, than those of the summer flowering species, such as E. camaldulensis and E. melliodom. An examination of environmental and tree-specific factors was undertaken to investigate relationships between flowering patterns of individually marked trees of E. microcarpa and E. tricarpa and a range of measures that may influence the observed patterns. A positive association with tree-size was the most consistent explanatory variable for variation between trees in the frequency and intensity of flowering. Competition from near-neighbours, tree health and the number of shrubs within the canopy area were also explanatory variables. The relationship between tree size and flowering phenology was further examined by using the marked trees of all seven species, selected to represent five size-classes. Larger trees (≥40 cm DBH) flowered more frequently, more intensely, and for a greater duration than smaller trees. Larger trees provide more abundant floral resources than smaller trees because they have more flowers per unit area of canopy, they have larger canopies in which more flowers can be supported, and they provide a greater abundance of floral resources over the duration of the flowering season. Heterogeneity in the distribution of floral resources was further highlighted by the study of flowering patterns of E. tricarpa at several spatial and temporal scales. A total of approximately 5,500 trees of different size classes were sampled for flower cover along transects in major forest blocks at each of five sample dates. The abundance of flowers varied between forest blocks, between transects and among tree size - classes. Nectar volumes in flowers of E. tricarpa were sampled. The volume of nectar varied significantly among flowers, between trees, and between forest stands. Mean nectar volume per flower was similar on each sample date. The study of large numbers of individual trees for each of seven species was useful in obtaining quantitative data on flowering patterns of species' populations and individual trees. The timing of flowering for a species is likely to be a result of evolutionary selective forces tempered by environmental conditions. The seven species' populations showed a similar pattern in the frequency and intensity of flowering between years (e.g. 1998 was a 'good' year for most species) suggesting that there is some underlying environmental influence acting on these aspects of flowering. For individual trees, the timing of flowering may be influenced by tree-specific factors that affect the ability of each tree to access soil moisture and nutrients. In turn, local weather patterns, edaphic and biotic associations are likely to influence the available soil moisture. The relationships between the timing of flowering and environmental conditions are likely to be complex. There was no evidence that competition for pollinators has a strong selective influence on the timing of flowering. However, as there is year-round flowering in this community, particular types of pollinators may be differentiated along a temporal gradient (e.g. insects in summer, birds in winter). This type of differentiation may have resulted in the co-evolution of floral traits and pollinator types, with flowers displaying adaptations that match the morphologies and energy requirements of the most abundant pollinators in any particular season. Spatial variation in flowering patterns was evident at several levels. This is likely to occur because of variation in climate, weather patterns, soil types, degrees of disturbance and biotic associations, which vary across the Box-Ironbark region. There was no consistency among sites between years in flowering patterns suggesting that factors affecting flowering at this level are complex. Blossom-feeding animals are confronted with a highly spatially and temporally patchy resource. This patchiness has been increased with human exploitation of these forests leading to a much greater abundance of small trees and fewer large trees. Blossom-feeding birds are likely to respond to this variation in different ways, depending upon diet-breadth, mobility and morphological and behavioural characteristics. Future conservation of the blossom-feeding fauna of Box-Ironbark forests would benefit from the retention of a greater number of large trees, the protection and enhancement of existing remnants, and revegetation with key species, such as E. leucoxylon, E. microcarpa and E. tricarpa. The selective clearing of summer flowering species, which occur on the more fertile areas, may have negatively affected the year-round abundance and distribution of floral resources. The unpredictability of the spatial distribution of flowering patches within the region means that all remnants are likely to be important foraging areas in some years.

Interaction of dietary fibre, carbohydrate metabolism and diabetes in the rat

It is currently accepted that the most appropriate diet in the treatment of non-insulin-dependent diabetes mellitus "e;NIDDM"e; is high in carbohydrates, high in fibre and low in fat. Dietary fibre reduces the rate of carbohydrate absorption, which may have a beneficial effect on insulin action. Furthermore, high fibre diets also increase the amount of carbohydrates which are not absorbed from the small intestine. These malabsorbed carbohydrates are fermented by the bacterial population in the large intestine, producing short chain fatty acids "e;SCFA"e;, including propionate, which has been shown to alter liver carbohydrate metabolism. This thesis investigated the actions of slowed carbohydrate absorption and carbohydrate malabsorption in streptozotocin-induced "e;STZ"e; diabetic rats. High carbohydrate diet supplemented with guar gum, a soluble dietary fibre, fed to STZ diabetic rats improved insulin sensitivity. investigation of the alterations in the stomach and small intestine demonstrated that guar increased the viscosity of the meal in the intestine. The action of increased fermentation, producing more propionate, was investigated by supplementing propionate into the diets of STZ diabetic rats or when perfused into isolated rat livers. No changes in insulin action or liver glucose metabolism were measured. in addition, it was shown that guar gum reduces food intake in STZ diabetic rats. Mild reductions in food intake in STZ diabetic rats were shown to increase insulin action. In summary, STZ diabetic rats fed high carbohydrate, high fibre diets reductions in food consumption and slowed carbohydrate absorption are important factors which may lower blood glucose concentrations and increase insulin action. increased SCFA production is unlikely to contribute significantly to the improvements in insulin action.

The trophic effect of dietary fibre is not associated with a change in total crypt number in the distal colon of rats

Soluble fibres, such as guar gum, promote and wheat bran or methylcellulose protect from chemically induced colon carcinogenesis, relative to the effect of a fibre-free diet in rats. Mechanisms are poorly understood. Whereas all fibres are trophic to the colonic epithelium, the heterogeneity of effects on carcinogenesis may reflect different effects on the total number of crypts and, therefore, the size of the stem cell population. This study aimed to assess this hypothesis. Sprague–Dawley rats were fed one of fibre-free diets with or without 10% wheat bran, methylcellulose or guar gum for 4 weeks. The distal colons were stained with methylene blue and quantified for the number and density of crypts using an image analysis system. Epithelial proliferative kinetics was measured stathmokinetically. Methodology for quantifying crypts was valid and reproducible. Rats fed a fibre-free diet had atrophic distal colon, as shown by a decrease in crypt column height and a lower mitotic index. Fibre supplementation prevented the atrophy and was associated with crypt mouth areas that were 30–60% larger than those in the fibre-free group (P < 0.001, ANOVA), with the methylcellulose group being the largest (1.16 µm2). The crypt density of the fibre-free group was 16–19% greater than those in fibre fed groups (P + 0.006), due to the smaller size of the crypts. However, there was no difference in the total number of crypts across the four dietary groups (P > 0.1). Distal colons in all of the dietary groups contained ~105 crypts. In conclusion, although variation in the amount or type of dietary fibre exerts heterogeneous effects on the growth of the colonic epithelium and on colon carcinogenesis, the total number of crypts in the distal colon remains constant. It is, therefore, unlikely that fibres influence carcinogenic events by altering the size of the stem cell population.

Importance of riparian vegetation to terrestrial avifauna along the Murray River, south-eastern Australia

Bird life occurring along the Murray River was distinctly different from surrounding much drier vegetation. It was found that the presence of the Murray River, with it's associated moist Red Gum forests, provide a corridor whereby birds typically of cool climates can expand their range and occur in an arid landscape.

Recent research on natural fibres and textiles

This paper provides an overview of recent research on a range of natural fibres and textiles. The focus is on work carried out at Deakin University’s Centre for Material and Fibre Innovation, which is a multidisciplinary research centre with over 100 researchers. The fibres include hemp, wool, silk, and alpaca fibres. Research on yarns, fabrics, and fine powders made from wool and silk fibres are briefly discussed also.

The within-fibre diameter variation of wool has been examined systematically, which highlights the importance of this hard-to-measure fibre attribute. A relationship between hemp fibre fineness and residual gum content has been established, which provides a rapid means of assessing the residual gum content in the degummed hemp fibres. Silk and wool fibres have been converted into ultrafine powders for advanced applications. The Resistance to Compression (RtC) behaviour of wool and alpaca fibres has been closely examined, which challenges the belief that RtC is a good indicator of fibre softness. Ways of reducing the hairiness of natural fibre yarns, predicting the pilling propensity of wool knits, and functionalising fabrics for superhydrophobicity and photochromic or colour changing effects are discussed.

Forgotten outcomes for rural areas in central policy-making : the case of blue gums in Australia

The expansion of private forestry and the partnership between government and private sector timber growers and processors highlights the issues associated with a functionally based rather than a place based approaches to changing patterns of land use in rural areas. Rural development through blue gum forestry was promoted as a means of revitalising rural communities, providing both economic and social gains to regional areas. The purpose of this study is to examine the economic consequences of policies designed to promote plantation forestry at a local level. It concludes that while plantation forestry may bring benefits to the national economy, these benefits may not be apparent at a local level especially if the industry operates in competition with a viable alternative.

Flooding requirements for biodiversity values along the Victorian floodplain of the Murray Valley

Overbank flooding of rivers is a key process in the maintenance of vegetation types and the species that rely on the floodplain forests and woodlands of northern Victoria. Yet the flooding requirements of species and vegetation types are poorly known. Here we present initial estimates of the water requirements for flood dependent Ecological Vegetation Classes (EVCs) and rare and threatened flora and fauna species associated with the floodplain of the Murray River and its tributaries. Some 110 EVCs were found to be at least partly flood-dependent on the Murray River floodplains. The total current extent of these EVCs in the study area is 224 247 ha, of which 162 266 ha are on public land. One hundred and twenty-four rare or threatened plant taxa and 62 threatened vertebrate fauna taxa (excluding fish) were classified as at least partly flood-dependent. These initial estimates provide important information for land and water managers and researchers alike.

Gyration

European Renaissance and Romantic landscape appeared in vistas. The conditions of the industrial revolution and, according to Patrick Maynard and Jonathon Crary, the film camera especially, led to a Modernist re-vision vividly recorded in Xavier Herbert’s contrary Modernist vision, prompted by seeing the Australian bush, its ‘... stunted trees, the mulga and the wilga and the gimlet gum, doing a kind of dance, spinning past, seeming to swing away from the train to the horizon and race ahead, to come back...the same set of trees in endless gyration’.

Preparing interprofessional clinical learning sites : what the literature tells us

Purpose: Infusing an interprofessional perspective into healthcare education in the university setting instils a collaborative approach in the provision of patient-centred care concepts for students. The purpose of this paper is to describe how one Australian health science faculty is modernising their healthcare education curriculum to develop this approach.

Method: As part of the development process, a systematic literature review was undertaken to determine the elements required for the development of interprofessional clinical learning (IPCL) sites, including but not limited to, necessary organisational and professional considerations to effect interprofessional education (IPE).

Results: The results of this review identified four key factors for IPE development: 1) shared culture, 2) support and leadership, 3) strategic facilitation and planning, and 4) effective feedback, evaluation and dissemination of curriculum intent.

Discussion: These elements are discussed in association with curriculum change in this faculty to promote interprofessional collaboration and teaching.

Conclusion: As a result of the review, the modernisation of our IPE curriculum is being underpinned by shared understandings between faculty and clinical site health providers about IPE. Our joint goal is for appropriate preparation and sustainability of IPCL sites.