Veterinary and Agricultural Sciences Collected Works - Theses
Now showing items 37-48 of 51
Taylors Creek revegetation analysis of plant establishment
Plant survival data was collected from parts of the Taylors Creek revegetation site approximately eighteen months post planting to determine the overall percentage survival rate of all species in the sample and the percentage survival rate of each species in the sample. This data is used to consider the efficacy of rationale and technique employed in the revegetation of Taylors Creek during 1986. Data was collected by a field survey of a randomly selected sample of planting areas comprising 12 percent of the total planting. Total percentage survival of the sample was 46 percent and the survival of each species ranged from 0 to 100 percent with a survival rate of 58 percent for the group of species best represented in the sample.
Conservation analysis of Burnley Gardens
V.C.A.H Burnley is a horticultural college surrounded by a historic landscape. The gardens were first established by the Horticultural Society of Victoria in 1863 for the acclimatisation of exotic plants especially fruit trees and in 1891 it became a School of Horticulture. A Significant Tree Study and Tree Census provides a current record of the vegetation and its condition. Through a series of maps and verbal descriptions the study depicts the changes that have occurred in the gardens from the 1860s to the present culminating in a Statement of Significance. To ensure the historical integrity of the gardens remains intact, a conservation policy has been formulated which has guided the development of the management recommendations.
Burnley Gardens landscape conservation analysis
Burnley Gardens has a history spanning 140 years. Its history parallels much of Victoria's history. From its earliest beginnings in 1861, it was involved in the assessment of produce for the growing colony. This vital work was undertaken by a group of prominent citizens, including Ferdinand von Mueller, and their society later became Victoria's Royal Horticultural Society. A victim of Australia's first Depression, Burnley Gardens was acquired in 1891 by the Victorian government, where it established Australia's first school of horticulture. So began its role in horticultural education in Australia, championing educational opportunities for women at a time when these were both controversial and limited. By promoting their admission and in many cases employing them as teachers, it provided support for the tenuous careers of Australia's pioneering women landscape designers. The changing needs of the workforce and the economy meant a shift in emphasis between production horticulture, agriculture, and amenity horticulture. Throughout au these changes, the grounds were used as an outdoor laboratory, with trialling of plants and education of students and the public undertaken. Burnley graduates were employed throughout Australia in every sphere of horticulture, and the Burnley method of horticultural practice was widespread throughout the country, influencing generations of people in the horticultural field. As a government institution, social policy was also implemented at Burnley. The initial geometric and symmetrical form of Burnley Gardens was redesigned between 1897 and 1907 in the English derived 'free' or landscape style, and though an actively utilised teaching garden, it has matured into a landscape of great ambience and beauty. Throughout its long history, Burnley Gardens has provided pleasure and respite from the neighbouring industrialized experience of Richmond, and for the wider Melbourne community. Burnley Gardens is of historic, social, scientific and aesthetic cultural significance to Victoria and Australia and holds a unique place in the history of this country.
The effectiveness of using native species for revegetation along urban waterways
This project investigates the effectiveness of using native plant species for revegetation along urban waterways. Five previously revegetated sites along Melbourne's linear waterways were studied. These sites include Diamond Creek, Merri Creek at Blyth Street and Hall Reserve, Plenty River and Taylor's Creek. Revegetation techniques were studied in order to determine the most successful strategies for urban revegetation. Observational techniques and surveys were used to evaluate the success of each individual project sites. All sites largely succeeded in achieving their original project aims, which included the use of indigenous vegetation, restoration of wildlife corridors, encouragement of passive recreation and use of regular maintenance. Criteria were used to assess the successful achievement of these aims, and `extra criteria' were developed to evaluate the success of other revegetation goals. The sites largely achieved satisfactory results for the extra criteria. Findings indicate a direct association between average leaf litter cover and average weed cover. This shows that high priority should be given to control and prevention of weeds through the application of mulch, and the development of strategies to increase leaf litter cover. Data also establishes that successful revegetation requires adequate planning, site preparation, site maintenance, consideration of landscape values and public awareness. The data enabled the development of recommendations, which can be used in the implementation of successful revegetation projects in the future.
The Burnley Garden conservation plan 1939-1999
This report is intended to form part II of a Conservation Plan for the Burnley gardens, which will assist in the conservation, and preservation of the Burnley Gardens located on the Yarra Boulevard, Richmond. The gardens have a long and rich history, the inception of the Royal Horticultural Society in 1863 provided the foundation for the Department of Agriculture. Horticultural and Agricultural practices and principals were taught for many years at Burnley and during this time the gardens have seen change and evolution to today where Horticultural training is practiced. They hold immense social, historical and scientific significance. The importance of this site cannot be underestimated and as a result thoughtful and strategic planning is needed in future management decisions. The Conservation Plan for the Burnley Gardens 1939-1999, forms the main part of this report and follows the internationally accepted Burra Charter in its format and language. This plan collates and analyzes the garden's history, identifies its value, and recommends policies that will both retain the garden's desirable ambience and guide it future use, giving due respect to the evolution of the student teaching component the gardens have fulfilled.
A history of Burnley Gardens 1860-1939
Historic Burnley Gardens in Richmond, Victoria are now part of the University of Melbourne. Horticultural and educational activities have existed on this site since the 1860's and 1890's respectively, with the Gardens initially established for testing fruit and produce to introduce into cultivation in the new colony of Victoria. Despite previous research into the history of the Gardens, the very early period around the time of establishment was not clear, and while it was known that many old and venerable trees grew on the site, it was not clear when they were planted, or the form that the early layout of the Gardens took. A two part research project was undertaken to answer these questions. Using documentary evidence and oral histories (where possible), the history of the Gardens from 1860 to 1939 was examined. A physical survey of the grounds was then carried out to determine what remained today from that period. Early photographs, plant lists, maps and plans were used to determine the position of previous driveways, fences and garden borders. Maps were drawn up to show the physical evolution of the Gardens over the time period being examined. As the Gardens' planting and design largely reflected the educational themes of the school on the site since education began on it in 1891, these themes have been linked to the Gardens' development. The remaining plant material such as trees, shrubs and climbers, path layout and surfacing material, buildings, rock structures, and water features were examined and recorded. The Gardens as it was up to 1939 was then contrasted with the Gardens as it is at the present time, with remaining plantings, layout and features identified. As a result, the history of the Burnley Gardens from 1860 to 1939 was able to be clarified, and a surprisingly large amount of extant material found.
Investigations of seed production potential of indigenous grassland forbs
This study investigated the potential for seed production, ex situ, from a range of forbs that were component species of grasslands and other grass-dominated plant communities in south-eastern Australia. Thirty-five species of native perennial forbs were collected from remnant grass-dominated plant communities in southern and western Victoria. All but one species (Tricoryne elatior, which did not germinate) were amenable to propagation and production in bark-based soil-less growing media in a variety of containers. Of 34 species, 29 (85%) flowered and produced seed within one year of propagation, and all species flowered and produced seed within 3 years. Of 20 species planted into field beds in autumn, 15 established successfully. The species generally were not amenable to spring planting in field beds. There was large variation between species in seed production potential due to differences in the number of flowers produced and the number of seeds produced per flower. Seasonal environmental effects on plant development and seed production were investigated in two studies. Firstly, Bulbine bulbosa and Craspedia variabilis were sown outdoors, in containers, at 12 sequential monthly intervals from 2/4/95 to 10/3/96. Both species established from all sowings but most flower and seed production occurred during spring and early summer, regardless of sowing date. For C. variabilis, sowings in January and February produced the most inflorescences per plant in the following spring. B. bulbosa plants produced visible buds approximately one month later than C. variabilis and were harvested 3 months later than equivalent sowings of C. variabilis. The second study investigated the potential for scheduling `out-of-season' production of seed. Seventeen species (that would normally be propagated in autumn) were sown in a greenhouse, and grown outdoors, on three occasions in late winter and spring (6/8/95, 3/9/95 and 1/10/95). Some plants of all but one species (Eryngium ovinum) flowered by April 1996, with 5 species exhibiting complete flowering in one or more sowings (Brachyscome dentata, Leptorhynchos tenuifolius, Velleia paradoxa, Wahlenbergia luteola, and W. stricto). Most species appeared to flower in response to interactions between cool (< 10 C) and warm (> 10 C) temperatures and to changes in photoperiod. It was concluded that to ensure synchronous flowering and, therefore, the potential for panmixis in out-breeding species, most species should be scheduled for flowering in their 'natural' flowering season. A method for improving the harvest efficiency of Bulbine bulbosa was investigated to replace the need for hand-harvesting of individual capsules. The yield, size and germination capacity of seed harvested from inflorescences that had been detached from the parent plant at a range of maturities, and dried at 20 degrees C, were compared to those of seed harvested from intact inflorescences. Seed yield was highest from intact inflorescences but daily harvests were required and harvests spanned a mean of 33 days per inflorescence, double the time needed for detached inflorescences to release all their seed. There was no significant difference between harvest methods in the number of seeds harvested per capsule, but there was a higher proportion of large seeds harvested from intact inflorescences. Germination was greater than 70% for all harvest treatments after 8 months of dry storage. Harvesting and drying inflorescences when one to three capsules had reached harvest maturity appeared to have the potential to increase harvest efficiency in B. bulbosa. The breeding system of Craspedia variabilis was examined in a greenhouse experiment that subjected inflorescences to one of three pollination treatments (none, hand self-pollination and hand cross-pollination). Cross-pollinated inflorescences produced an average of 301 achenes per capitulum, significantly more than either self-pollinated or non-pollinated inflorescences (19 and 15, respectively). It was concluded that C. variabilis is strongly out-breeding and largely self-incompatible. It was concluded that many perennial forb species were amenable to growth in containers but that seed production potential varied between species. For the genetic diversity sampled from remnant populations to be represented in seed produced in cultivated plants, the seed production system must take full account of the breeding system requirements and seasonal influences on flowering and seed production, for each species.
Responses of tree roots to post-planting waterlogging and soil compaction
Plants growing in urban soils are frequently subject to waterlogging and changes in soil strength due to compaction and fluctuations in watertables, and variations in texture and bulk density due to the disturbed nature of urban soils. A waterlogging trial was set up to test the ability of recently planted trees to grow new roots under waterlogged conditions and to recover from this period of waterlogging. Corymbia maculata, Lophostemon confertus, Platanus orientalis and Platanus X acerifolia were subjected to a period of waterlogging and then a recovery phase after waterlogging had ceased. Root length was measured at the end of the waterlogging phase, and at the end of the recovery phase. The different species were found to vary considerably in their ability to tolerate and recover from a period of waterlogging. Waterlogging suppressed shoot and root growth in all species trialed. Corymbia maculata, and Platanus orientalis were able to initiate new roots under waterlogged conditions. Platanus X acerifolia and Lophostemon confertus were not able to do this. Compaction trials were set up to test the hypothesis that trees which are able to establish in urban soils will have a higher than average tolerance to soil compaction and to the higher mechanical impedance and soil strength in dry compacted soils. Compaction Trial A tested the ability of the roots of Corymbia maculata, Lophostemon confertus, Corymbia ficifolia and Agonis flexuosa seedlings to penetrate soil cores compacted to bulk density 1.4 and 1.8 Mg/m3 at 13 % gravimetric moisture content. While roots of all species were able to penetrate the soil at the higher bulk density, total root penetration depth was reduced by 60 % across all the species. Compaction Trial B tested the ability of Corymbia maculata and Corymbia ficifolia to penetrate soil compacted at bulk densities 1.4, 1.6 and 1.8 Mg/m3 at two moisture levels, 7 and 10 % gravimetric moisture. At 7 % moisture, both species were able to penetrate soil compacted to 1.4 and i .6 Mg/m3, but neither species was able to successfully penetrate soil compacted to 1.8 Mg/m3. At 10 % moisture, both species were able to penetrate soil compacted to 1.4 and 1.6 Mg/m3. They were also able to successfully penetrate soil compacted to 1.8 Mg/m3, although with significantly less depth of penetration.
Some calculations of potential photosynthetic yield
Detailed calculations of light relations and seasonal potential photosynthesis are carried out for models of leaf canopies of closed trellis orchard design, with the object of comparing the effectiveness of light capture and usage in canopies of various fork angles and various values of leaf area index. It is assumed that all canopies have adequate water, carbon dioxide and nutrients, a condition satisfied in practical orchards. After examination of a very simple model, a detailed model is set up to take full account of direct sunlight, diffuse skylight and light scattered diffusely by foliage. Irradiance at leaf surfaces of various orientations is calculated from first principles, since in a canopy whose geometry is not independent of azimuth there is no straightforward way of assessing diffuse irradiance. An analytical expression is derived for rate of photosynthesis averaged over sunlit leaves randomly oriented in azimuth at any given isotropic diffuse irradiance. The calculated field of photosynthetically active radiation is used to estimate canopy net photosynthesis during the fruit-filling season for peach orchards. In such canopies the foliage-scattered diffuse light is found to make a relatively small contribution (about 10 percent) to net canopy photosynthesis. It is found that for any given value of leaf area index the seasonal potential photosynthesis, whether net or gross, increases as canopy fork angle increases, in the range of angles from 40 degrees to 180 degrees. The estimated absolute harvest yield of peaches in a 60 degree canopy is found to be lower than the mean value of published measured yields by about one standard deviation. Reasons for this are discussed. The low estimated yield does not affect the validity of theoretical comparison between the various canopies. One of several possible causes of an underestimate of potential photosynthesis is neglect of penumbral effects. A theoretical framework is developed for estimation of the error introduced in photosynthesis calculations by the assumption that incident direct solar radiation is a perfectly parallel beam of light. The calculations of Miller and Norman (1971) on distribution of direct sunlight flux density along transects in sunflecks are discussed. The present theory is developed in terms of probabilities of irradiation by full sun and by partially shaded sun and the probability of umbra at any level in a leaf canopy. Analytical expressions are derived for probability density with respect to fraction of the full sun radiant flux density for partial shading by a straight edge, a circular disk, and a thin strip. It is shown that solar limb darkening may be neglected for the present purpose. The geometry of umbra and penumbra due to crossed shading edges is discussed and quantified. The developed theory is applied to hypothetical canopies of randomly dispersed horizontal circular leaves and to randomly oriented and dispersed vertical leaves. A parameter called the characteristic leaf area index is introduced; this parameter, which includes foliage density and leaf dimensions, may be used in assessing the error in estimated canopy photosynthesis due to neglect of penumbra. Application of the theory to the effects of vertical distribution of foliage on canopy photosynthesis is briefly discussed. The underestimate of potential canopy photosynthesis in a peach tree canopy due to neglect of penumbra is found to be of order 5 percent.
The effect of nano-chromium on growth performance and metabolism of pigs and sheep
Chromium (Cr) is an essential mineral element for humans and animals. Various forms of Cr have been used in farm animals in order to improve growth performance, insulin sensitivity, immune response, carcase traits and to reduce stress responsiveness. However, Cr is normally poorly absorbed and utilised even when supplemented in an organic form, perhaps in part because of the tendency to form large aggregates. Interestingly, the efficiency of uptake of 100 nm size particle by intestinal tissue was 15 to 250 fold higher compared to 1μm size particles. This thesis aims to develop a novel nano sized Cr tri-picolinate (nCrPic) and examined the effect of nCrPic on growth performance, body composition and physiological and metabolic response to dietary fat and heat stress in pigs and sheep. Four experiments involving different particles size Cr, different dose nCrPic and cinnamon were fed to gilts over the growing-finishing phase and sheep to evaluate the effect of nCrPic and cinnamon on growth performance, carcase trait, and glucose metabolism. In the first experiment, finisher gilts were allocated to eight treatment groups in a 2×4 factorial treatment structure. The respective factors were dietary fat (22 or 57 g/kg) and dietary Cr (0, 400 ppb normal size CrPic, 400 ppb 1μm CrPic (μCrPic) and 400 ppb nm CrPic (nCrPic)). Over the first 21 days, ADG was increased by dietary CrPic, although there was no difference between the different sized Cr. High dietary fat also increased ADG over this period. Dietary CrPic increased carcase weight and muscle depth with responses being greatest for nCrPic. Also, dietary CrPic decreased P2 back fat with the greatest response seen in pigs fed nCrPic and a high fat diet. Furthermore, dietary CrPic tended to decrease plasma insulin without changing plasma glucose indicating an improvement in insulin sensitivity. Moreover, work reported in this thesis further examined the changes occurring at the mRNA level in finisher gilts fed with nCrPic (0 or 400 ppb nCrPic) and fat (22 or 57 g/kg). Skeletal muscle and subcutaneous adipose tissue were collected 25 minutes post-slaughter. This experiment provided some strong evidence that dietary nCrPic can improve insulin sensitivity in pigs consuming a high fat diet. In particular, the expression of the insulin-signaling pathway genes PI3K and AKT were increased by dietary nCrPic. Furthermore, the expression of SOCS3 in skeletal muscle, which can aggravate insulin resistance, was reduced by nCrPic. Dietary nCrPic also increased UCP3 and IL-15 in skeletal muscle, both of which facilitate glucose metabolism. In subcutaneous adipose tissue, the expression of adiponectin was up-regulated by dietary nCrPic. These findings indicate the improvement in the insulin-signaling pathway by dietary nCrPic may be via decreased SOCS3 and increased UCP3 and IL-15 in skeletal muscle, as well as increased adiponectin in subcutaneous adipose tissue. The second experiment was designed to examine the effects of nCrPic on growth performance, carcase traits in finisher gilts under commercial pig production facility. Finisher pigs were allocated to either control or nCrPics treatment during the mid-summer (January-February, 2011). The average maximum temperature during the experiment was 29.7 oC, with a total of 24 days where the daily maximum temperature was above 28 oC. The data reported in this chapter indicated that dietary nCrPic supplementation at 400 ppb can increase feed intake in finisher gilts during mid-summer suggesting that nCrPic can ameliorate some of the negative effects of heat stress in pigs, possibly via decrease of circulatory cortisol. These results provided an interesting insight into the anti- heat stress response of nCrPic in farm animals. The third experiment investigated the effects of two different doses (400 ppb and 800 ppb nCrPic) in sheep. Additionally, the physiological responses to chronic heat stress were also examined. Animals were exposed to temperatures of either an average 22.3 °C ambient temperature for thermo-neutral control or peak at an average 40.4 °C for heated animals. The higher ambient temperature resulted in increased rectal and skin temperature, respiration rate, and reduced feed intake and weight gain. Dietary nCrPic ameliorated the increase in rectal temperature observed during heat load. Moreover, dietary nCrPic supplementation also increased feed intake and weight gain when animals were exposed to heat treatment. The metabolic and tissue responses to nCrPic are examined by subjecting these sheep to glucose, insulin and ACTH challenges to assess the metabolic responses to both heat and nCrPic. Tissue samples were also examined for the gene expression responses to heat and nCrPic. In response to the glucose tolerance test, basal plasma glucose was decreased by heat treatment and dietary nCrPic. Sheep fed nCrPic had a lower glucose response as assessed as area under the curve (AUC) and insulin AUC in response to glucose infusion. Animals under heat treatment had a lower NEFA AUC response to glucose infusion. Dietary nCrPic also down regulated the expression of JNK in skeletal muscle tissue. Together, the results from this experiment indicated that nCrPic can improve insulin sensitivity when animal under heat stress and the improvement of insulin sensitivity may be via decrease the expression of JNK in skeletal muscle tissue. A large number of endocrine and inflammatory pathways have been shown to be dysregulated in obesity. These endocrine and inflammatory factors that reduce body fat deposition are usually associated with an improvement in insulin sensitivity. Data from the first experiment showed that dietary nCrPic can decrease body fat and improve insulin sensitivity. Furthermore, cinnamon has been reported to have similar effects to Cr. The fourth experiment reported in this thesis examined the impact of oral supplementation with nCrPic and cinnamon on body fat deposition and insulin resistance in a high fat fed pig model. Data from this experiment provided evidence that dietary nCrPic and cinnamon have effects on glucose and fat metabolism. In particular, dietary nCrPic and cinnamon can improve insulin sensitivity metabolically and via the insulin signaling gene AKT and GLUT4 mRNA expression. Some of these effects may be mediated, at least in part, by alterations in fatty acid oxidation as the evidence showed that UCP3 and CPT-1B mRNA expression in skeletal muscle were up-regulated by dietary nCrPic and cinnamon supplementation. The results presented in this thesis conclude that heat stress is able to impact nutrient partitioning and metabolism. Dietary nCrPic supplementation can improve growth performance and carcase traits as well as amelioration of the negative effect of heat stress is possibly via improved insulin sensitivity. Both nCrPic and cinnamon activate insulin receptors by up-regulating insulin signaling gene expression such as PI3K, AKT, and GLUT4, and genes involved in fatty acid oxidation such as UCP3 and CPT-1B.