Academic literature on the topic 'Eucalypt woodland'

Allometric equations are presented relating stem circumference to branch, leaf, trunk, bark, total above-ground and lignotuber biomass for Eucalyptus crebra F.Muell. (woodland trees), E. melanophloia Sol. Ex Gaerth. (both woodland and regrowth community trees) and E. populnea F.Muell. (woodland trees). There were no significant differences (P > 0.05) between the slopes of individual lognormal regression lines plotting stem circumference against total above-ground biomass for E. crebra, E. melanophloia and E. populnea. Root-to-shoot ratios and leaf area indices were also determined for the stands contributing to each regression. The regressions were then applied to measured eucalypt stems in the associated plant community to give estimates of each stand’s component (eucalypt tree fraction only) biomass per hectare. These eucalypt regressions were next applied to measured stems of each species on a total of 33 woodland sites in which these eucalypts individually contributed > 75% of total site basal area. Above-ground biomass/basal area relationships averaged 6.74 0.29 t m–2 basal area for 11 E. crebra sites, 5.11 0.28 t m–2 for 12 E. melanophloia sites and 5.81 0.11 t m–2 for 10 E. populnea sites. The mean relationship for all sites was 5.86 0.18 t m–2 basal area. The allometric relationships presented at both individual tree and stand levels, along with calculated biomass : basal area relationships, enable ready estimates to be made of above-ground biomass (carbon stocks) in woodlands dominated by these eucalypts in Queensland, assuming individual stem circumferences or community basal areas are known. However, to document changes in carbon stocks (e.g. for Greenhouse Gas Inventory or Carbon Offset trading purposes), more attention needs to be placed on monitoring fluxes in the independent variables (predictors) of these allometric equations.

Temperate eucalypt woodlands were once widespread throughout southern Australia and Tasmania. Following European settlement, woodlands were cleared for agriculture, or grazed and converted to pasture. In the wheatbelts of south-western and south-eastern Australia, woodlands have been almost completely eliminated from the landscape with as little as 3% of some woodland types remaining. As a consequence, some temperate eucalypt woodland communities are amongst the most poorly conserved ecosystems in Australia. The main effect of widespread clearing and grazing has been the loss of habitat. This has had a devastating impact on the woodland flora and fauna. A number of species have become extinct and many are threatened; many others have undergone regional and local population declines. Woodlands now occur throughout much of their former range as remnants of varying size, quality and isolation. Many of these are under threat from further clearing, rising saline water tables and increased inundation, livestock grazing, nutrient enrichment, soil structural decline, altered fire regimes and the invasion of exotic weeds. The degradation and loss of biodiversity in temperate eucalypt woodlands will continue unless clearing stops and the management of remnants changes; this will invariably involve ecological restoration both at the patch and landscape level. The review discusses approaches to restoration and reveals that there are few data in the published literature describing techniques for reversing degrading processes and restoring diversity structure and function in remnant woodlands. This information is urgently needed. Past research on temperate eucalypt woodlands has focused on identifying the processes of degradation and these are now relatively well documented. There is a need to shift the focus of research to developing solutions for these problems.

The abundance of an aggressive Australian honeyeater, the Noisy Miner Manorina melanocephala, was reduced at four small (<8 ha) Grey Box Eucalyptus microcarpa woodland remnants by experimental removal. The diversity and abundance of small insectivorous and nectarivorous birds increased at three of the four sites (relative to matching control sites) over the twelve months following the removal of the Noisy Miners. The one exception occurred at a pair of sites where eucalypts began flowering at one site and finished at the other during the Noisy Miner removal period. These results, taken together with those from three earlier experiments where the abundance of Noisy Miners was reduced in Mugga Ironbark E. Sideroxylon woodland remnants, demonstrate that Noisy Miners affect avian diversity and abundance by aggressive exclusion of other species. In five out of seven experiments, Noisy Miners did not reinvade the small woodland remnants during the ensuing twelve months. When Noisy Miner abundance was reduced, increased populations of small insectivorous and nectarivorous birds used small degraded woodland remnants. Colonizing populations of small birds have the potential to reduce insect infestations and may assist in the recovery of dieback-affected woodland remnants. Research is continuing to test this hypothesis. Reducing the abundance of Noisy Miners in remnant eucalypt woodlands may also be a useful, short-term measure, which could assist in the recovery of threatened or endangered bird species.

Southern Australia has a tree crisis. The iconic and ecologically essential eucalypt trees are dying out across vast swathes of farmland that were once grassy woodlands. A century of clearing and agricultural intensification, plus the failure of these trees to self-regenerate, has led to a massive loss of wildlife habitat, particularly tree hollows that only form in large and old Eucalyptus trees. Just as importantly, this decline in trees has exposed farmers to losses of agricultural productivity. There is now a lack of shelter for livestock. Rising salty ground water is degrading pastures as this ground water is no longer being controlled by the deep roots and respiration of eucalypts. We describe the research that shows how an innovative partnership between farmers, a non-government environmental organisation, and government funding is rehabilitating entire fields to a productive and wildlife-rich woodland full of thriving eucalypts.

In Australian temperate woodlands, most squirrel glider (Petaurus norfolcensis) habitats exist outside formal conservation reserves, often in highly fragmented agricultural landscapes. To conserve squirrel glider populations in such woodlands it is essential to define important habitats and understand how they are used. This study examines the nocturnal habitat use of squirrel gliders across five sites within an agricultural landscape in south-eastern Australia. Over a five-month period we radio-tracked 32 gliders to 372 nocturnal locations. We quantify characteristics of key nocturnal habitats and describe their use. Gliders were more likely to use large eucalypt trees, particularly yellow box (Eucalyptus melliodora) and mugga ironbark (E. sideroxylon). Nocturnal activity mostly took place high in the canopy of eucalypts, accounting for 74% of fixes. Multiple regression models revealed that feeding was more likely to occur in large, healthy trees close to drainage lines, with a preference for E. melliodora, when eucalypts were not flowering. Flowering trees were preferentially sought and were strongly associated with being large healthy trees that occur on ridges and upper slopes. Showing that the squirrel glider utilises key feeding structures (large healthy Eucalyptus trees) in different parts of the landscape at different times has direct management implications in the conservation and restoration of squirrel glider habitat, particularly in fragmented temperate woodland.

Exotic plants are a major threat to native plant diversity in Australia yet a generic model of the invasion of Australian ecosystems by exotic species is lacking because invasion levels differ with vegetation/soil type and environmental conditions. This study compared relative differences in exotic species invasion (percent cover, spp. richness) and the species richness of herbaceous native plants in two structurally very similar vegetation types, Gimlet Eucalyptus salubris and Wandoo E. capillosa woodlands in the Western Australian wheatbelt. For each woodland type, plant variables were measured for relatively undisturbed woodlands, woodlands with >30 years of livestock grazing history, and woodlands in road-verges. Grazed and road-verge Gimlet and Wandoo woodlands had significantly higher cover of exotic species, and lower species richness of native plants, compared with undisturbed Gimlet and Wandoo. Exotic plant invasion was significantly greater in Gimlet woodlands for both grazed (mean 78% cover) and road-verge sites (mean 42% cover) than in comparable sites in Wandoo woodlands (grazed sites 25% cover, road-verge sites 19% cover). There was no significant difference in the species richness of exotic plants between Wandoo and Gimlet sites for any of the three situations. Mean site richness of native plants was not significantly different between undisturbed Wandoo and undisturbed Gimlet woodlands. Undisturbed woodlands were significantly richer in plant species than grazed and road-verge woodlands for both woodland types. Grazed and road-verge Wandoo sites were significantly richer in plant species than communities in grazed and road-verge Gimlet. The percent cover of exotics was negatively correlated with total (native) plant species richness for both woodland types (Wandoo r = ?0.70, Gimlet r = ?0.87). Of the total native species recorded in undisturbed Gimlet, 83% and 61% were not recorded in grazed and road-verge Gimlet, respectively. This compared with 40% and 33% for grazed and road-verge Wandoo, respectively. Grazed Wandoo and grazed Gimlet sites had significantly fewer native plant species than did road-verge Wandoo and road-verge Gimlet sites. Ecosystem implications of differential invasions by exotic species, and the effects of grazing (disturbance) and other factors influencing susceptibility to exotic plant invasion (landscape, competition and allelopathy) on native species decline are discussed. Exclusion of livestock and adequate methods of control and prevention of further invasions by exotic plants are essential requirements for the conservation of these woodland systems.

In December 2005, a wildfire burnt a large area of semi-arid eucalypt woodland along ~10 km of the Norseman- Coolgardie Road north of Norseman in the Great Western Woodlands (GWW), Western Australia. Few birds used the burnt area in the first year after the fire and these were mainly ground and shrub foraging insectivores. There was no influx of seed-eaters or open-country species as reported for post-fire habitats elsewhere in southern Australia. The greatest number of individuals and species of birds occurred in the second year post-fire when ground and shrub vegetation was floristically most diverse. Canopy foragers were attracted to the burnt area in the second year by an outbreak of psyllid insects on seedling eucalypts. At the same time, bark dwelling arthropods associated with the standing stems of fire-killed eucalypts attracted bark-foragers. From the third year, small insectivorous ground, shrub, and canopy foragers dominated the avifauna on the burnt area. These foraged on fire-killed shrubs, as well as living vegetation, including the lignotuberous regrowth of eucalypts. Bark foragers were uncommon after the second year. Throughout the study, the burnt area had fewer species and individuals than adjacent unburnt habitats. Compared with unburnt woodlands there were few differences in how species foraged on the burnt plots, but most species foraged lower reflecting the stature of the vegetation in the burnt woodland. Nectar-feeders, fruit-eaters, large insectivores, raptors, and parrots, although common in the unburnt woodland, were absent or rare in the burnt area. This reflected the limited regrowth of vegetation on the burnt area, which lacked the structural and floristic complexity of nearby unburnt woodlands. Ground foragers probably commenced nesting on the burnt area in the first year, with shrub and canopy foragers nesting from the second year. However, after five years, there was no evidence of large insectivores, nectar-feeders, raptors, seed-eaters, or foliage-eaters (i.e., parrots) nesting despite their abundance in adjacent unburnt woodland. Some of the unburnt woodlands monitored in this study were even-aged regeneration estimated to be 30–50 years post-fire or logging. Regardless of origin, these even-aged plots lacked the diverse avifauna associated with mature woodlands and suggest that post-fire recovery of birds and vegetation in these woodlands is likely to take decades and probably more than 100 years. If so, human activities that increase fire frequency in the GWW, including climate change and fuel-reduction burns, will have long-term adverse impacts on regional biodiversity exceeding those associated with wildfires in less arid forests and woodlands where rates of recovery are more rapid.

Downslope boundaries of forest with grassland and grassy woodland occur over a wide altitudinal range in central Tasmania. Three sites were selected for study of the causes of these boundaries at low, medium and high elevations. The open vegetation was generally associated with moister and less rocky soils and more subdued topography than the adjacent forest. Frost incidence and intensity, soil moisture and waterlogging varied markedly among the three open areas. Planted tree seedlings survived 4 years in the open at all sites, and seedlings established in the open both naturally, and after sowing, where grass competition was reduced by herbicide application, digging or root competition from adult eucalypts. Grazing had no detectable effect on seedling establishment. A pot experiment demonstrated a suppressive effect of native grass swards on both seedling establishment and growth, this effect being largely independent of available moisture and nutrients. While frost, waterlogging, fire and drought may play a role in inhibiting eucalypt establishment and increasing eucalypt mortality at some or all of the sites, the dense grass swards found in all the open areas are considered to be the most likely primary agent of tree exclusion.

Diet of Petaurus breviceps in a coastal woodland and heath mosaic was assessed by timed feeding observations and qualitative faecal analysis. Feeding at banksia and eucalypt flowers was the most observed foraging behaviour. Faeces contained abundant pollen. The pattern of foraging closely followed changes in patterns of flowering in the area because P. breviceps regularly visited flowers for nectar and pollen. It fed at a faster rate per flower when foraging on eucalypts, but had a high number of inter-plant movements when foraging on banksias. Seventy-one per cent of Eucalyptus gummifera trees were incised to obtain sap. Values obtained for sap flow showed that incised trees exuded more sap than non-incised ones. Gum was abundant at Jervis Bay, and sap may be utilised when nectar is abundant.

In the south-western region of Australia, allometric relationships between tree dimensional measurements and total tree biomass were developed for estimating carbon sequestered in native eucalypt woodlands. A total of 71 trees representing eight local native species from three genera were destructively sampled. Within this sample set, below ground measurements were included for 51 trees, enabling the development of allometric equations for total biomass applicable to small, medium, and large native trees. A diversity of tree dimensions were recorded and regressed against biomass, including stem diameter at 130 cm (DBH), stem diameter at ground level, stem diameter at 10 cm, stem diameter at 30 cm, total tree height, height of canopy break and mean canopy diameter. DBH was consistently highly correlated with above ground, below ground and total biomass. However, measurements of stem diameters at 0, 10 and 30 cm, and mean canopy diameter often displayed equivalent and at times greater correlation with tree biomass. Multi-species allometric equations were also developed, including ‘Mallee growth form’ and ‘all-eucalypt’ regressions. These equations were then applied to field inventory data collected from three locally dominant woodland types and eucalypt dominated environmental plantings to create robust relationships between biomass and stand basal area. This study contributes the predictive equations required to accurately quantify the carbon sequestered in native woodland ecosystems in the low rainfall region of south-western Australia.

The goal of this work was to quantify the effects of eucalypt woodland blocks on the productivity of native pastures. This research was conducted on the Southern Tablelands of New South Wales. Tree planting or retention is seen by many as an important tool in addressing the problems of soil degradation resulting from clearing and pasture improvement that threaten the sustainability of pasture systems. In particular these are dry land salinity and erosion, both of which affect large areas of agricultural lands in the south east of Australia. Whilst native tree cover remains over substantial portions of Australian pasture lands, mainly on steeper slopes and poorer soils, little has been done to measure the effects of trees on pasture productivity and soil fertility on the Southern Tablelands. Previous studies in other areas have shown a range of effects�from facilitation to inhibition�of pasture growth in the presence of trees. Soil fertility beneath trees has been shown by a number of workers to be elevated in comparison with situations in the open. Given that the range of effects may be highly site dependent, application of results from one area to another may not be valid. Thus it is necessary to measure tree effects on a regional scale if results are to be reliable. Pasture productivity was assessed over a two year period on four sites in the vicinity of Bungendore, New South Wales. A pair of plots was selected on each site, one plot in a block of eucalypt woodland, and the other nearby in an exposed, open situation. Plots were chosen to be as similar to each other as possible with the exception of tree cover. Treed plots had a tree basal area of between 10 and 20 m2 ha-1 and plots had an area of 900 m2. Two of the sites were on granitic soils and had a tree cover consisting predominantly of Eucalyptus pauciflora. The remaining two sites were on soil derived from sedimentary rocks with tree cover consisting mainly of E. mannifera, E. dives and E. melliodora. Perennial native pasture species present were similar across all sites, although their relative contributions to standing biomass varied between sites. As the plots were grazed during the period of measurement, productivity and offtake were measured seasonally using exclosure cages on each plot. Pasture standing biomass was assessed using the comparative yield technique. Microclimate was monitored in each plot by automatic weather stations. Soil moisture to a depth of 45 cm was measured by time domain reflectometry using permanent probes in each plot. Ten additional survey plots on each site, covering the range of tree basal area from 0 - 30 m2 ha-1, were assessed each season in the second year for standing biomass, soil fertility and pasture quality; expressed by nitrogen content and dry matter digestibility. Pasture floristics were measured using the dry-weight-rank method. These additional plots were chosen to be as representative of the paddocks as possible. Over the two years that productivity was measured, it was found to be higher under trees than in the open. This was predominantly due to higher winter and spring growth within treed plots. Grazing offtake was also found to be higher under trees, partly accounting for lower standing biomass found in the treed plots. Wind run, evapotranspiration and photosynthetically active radiation were all reduced by the presence of trees. Beneficial effects of shelter from winds may largely explain the higher productivity observed in the treed plots, and could outweigh negative effects of below ground competition and radiation interception by tree canopies at low to moderate tree densities. Soil moisture was not affected by the presence of trees. Soil fertility also did not differ between treed and open plots nor was there any difference in pasture nitrogen content or dry matter digestibility. On the sites where soils were derived from sedimentary rocks, pasture floristics were found to be related to tree basal area. Themeda ausfralis biomass was negatively related to tree basal area, and was partially replaced by large tussock species such as Poa sieberiana and Chionochloa pallida. A reduction of pasture quality resulted, particularly as the latter species is not grazed to any significant extent. Given the desirability of having deep rooted perennial components in grazing lands, the results of this study indicate that it may be possible to utilise trees to assist in preventing or reducing a range of adverse environmental consequences arising from agricultural activities, without unduly compromising pasture productivity. Additionally, the wide range of environmental conditions provided by a mix of treed and open pasture promotes a higher degree of heterogeneity of the herbaceous layer. This may assist in maintaining productivity over a greater range of climatic conditions than would be the case with a more homogeneous pasture.

In this thesis I present and test a methodology for developing a stand scale index of structural complexity. If properly designed such an index can act as a summary variable for a larger set of stand structural attributes, providing a means of ranking stands in terms of their structural complexity, and by association, their biodiversity and vegetation condition. This type of index can also facilitate the use of alternative policy instruments for biodiversity conservation, such as mitigation banking, auctions and offsets, that rely on a common currency – the index value – that can be compared or traded between sites. My intention was to establish a clear and documentable methodology for developing a stand scale index of structural complexity, and to test this methodology using data from real stands.¶ As a starting point, I reviewed the literature concerning forest and woodland structure and found there was no clear definition of stand structural complexity, or definitive suite of structural attributes for characterising it. To address this issue, I defined stand structural complexity as a combined measure of the number of different structural attributes present in a stand, and the relative abundance of each of these attributes. This was analogous to approaches that have quantified diversity in terms of the abundance and richness of elements. It was also concluded from the review, that stand structural complexity should be viewed as a relative, rather than absolute concept, because the potential levels of different structural attributes are bound within certain limits determined by the inherent characteristics of the site in question, and the biota of the particular community will have evolved to reflect this range of variation. This implied that vegetation communities with naturally simple structures should have the potential to achieve high scores on an index of structural complexity.¶ I proposed the following five-stage methodology for developing an index of stand structural complexity: 1. Establish a comprehensive suite of stand structural attributes as a starting point for developing the index, by reviewing studies in which there is an established relationship between elements of biodiversity and structural attributes. 2. Develop a measurement system for quantifying the different attributes included in the comprehensive suite. 3. Use this measurement system to collect data from a representative set of stands across the range of vegetation condition (highly modified to unmodified) and developmental stages (regrowth to oldgrowth) occurring in the vegetation communities in which the index is intended to operate. 4. Identify a core set of structural attributes from an analysis of these data. 5. Combine the core attributes in a simple additive index, in which attributes are scored relative to their observed levels in each vegetation community.¶ Stage one of this methodology was addressed by reviewing a representative sample of the literature concerning fauna habitat relationships in temperate Australian forests and woodlands. This review identified fifty-five studies in south-east and south-west Australia, in which the presence or abundance of different fauna were significantly (p<0.05) associated with vegetation structural attributes. The majority of these studies concerned bird, arboreal mammal, and ground mammal habitat requirements, with relatively fewer studies addressing the habitat requirements of reptiles, invertebrates, bats or amphibians. Thirty four key structural attributes were identified from these fifty-five studies, by grouping similar attributes, and then representing each group with a single generic attribute. This set, in combination with structural attributes identified in the earlier review, provided the basis for developing an operational set of stand level attributes for the collection of data from study sites.¶ To address stages two and three of the methodology, data were collected from one woodland community –Yellow Box-Red Gum (E. melliodora-E. Blakelyi ) – and two dry sclerophyll forest communities – Broadleaved Peppermint-Brittle Gum (E. dives-E. mannifera ), Scribbly Gum-Red Stringybark (E. rossii E. macrorhyncha ) – in a 15,000 km2 study area in the South eastern Highlands Bioregion of Australia. A representative set of 48 sites was established within this study area, by identifying 24 strata, on the basis of the three vegetation communities, two catchments, two levels of rainfall and two levels of condition, and then locating two sites (replicates) within each stratum. At each site, three plots were systematically established, to provide an unbiased estimate of stand level means for 75 different structural attributes.¶ I applied a three-stage analysis to identify a core set of attributes from these data. The first stage – a preliminary analysis – indicated that the 48 study sites represented a broad range of condition, and that the two dry sclerophyll communities could be treated as a single community, which was structurally distinct from the woodland community. In the second stage of the analysis, thirteen core attributes were dentified using the criteria that a core attribute should:¶ 1. Be either, evenly or approximately normally distributed amongst study sites; 2. Distinguish between woodland and dry sclerophyll communities; 3. Function as a surrogate for other attributes; 4. Be efficient to measure in the field. The core attributes were: Vegetation cover <0.5m Vegetation cover 0.5-6.0m; Perennial species richness; Lifeform richness; Stand basal area of live trees; Quadratic mean diameter of live stems; ln(number of regenerating stems per ha+1); ln(number of hollow bearing trees per ha+1);ln(number of dead trees per ha+1);sqrt(number of live stems per ha >40cm dbh); sqrt(total log length per ha); sqrt(total largelog length per ha); Litter dry weight per ha. This analysis also demonstrated that the thirteen core attributes could be modelled as continuous variables, and that these variables were indicative of the scale at which the different attributes operated.¶ In the third and final stage of the analysis, Principal Components Analysis was used to test for redundancy amongst the core attributes. Although this analysis highlighted six groupings, within which attributes were correlated to some degree, these relationships were not considered sufficiently robust to justify reducing the number of core attributes.¶ The thirteen core attributes were combined in a simple additive index, in which, each attribute accounted for 10 points in a total index value of 130. Attributes were rescaled as a score from 0-10, using equations that modelled attribute score as a function of the raw attribute data. This maintained a high correlation (r > 0.97, p< 0.0001) between attribute scores and the original attribute data. Sensitivity analysis indicated that the index was not sensitive to attribute weightings, and on this basis attributes carried equal weight. In this form my index was straightforward to apply, and approximately normally distributed amongst study sites.¶ I demonstrated the practical application of the index in a user-friendly spreadsheet, designed to allow landowners and managers to assess the condition of their vegetation, and to identify management options. This spreadsheet calculated an index score from field data, and then used this score to rank the site relative to a set of reference sites. This added a regional context to the operation of the index, and is a potentially useful tool for identifying sites of high conservation value, or for identifying sites where management actions have maintained vegetation quality. The spreadsheet also incorporated the option of calculating an index score using a subset of attributes, and provided a measure of the uncertainty associated with this score.¶ I compared the proposed index with five prominent indices used to quantify vegetation condition or habitat value in temperate Australian ecosystems. These were: Newsome and Catling’s (1979) Habitat Complexity Score, Watson et al.’s (2001) Habitat Complexity Score, the Site Condition Score component of the Habitat Hectares Index of Parkes et al. (2003), the Vegetation Condition Score component of the Biodiversity Benefits Index of Oliver and Parkes (2003), and the Vegetation Condition Score component of the BioMetric Assessment Tool of Gibbons et al. (2004). I found that my index differentiated between study sites better than each of these indices. However, resource and time constraints precluded the use of a new and independent data set for this testing, so that the superior performance of my index must be interpreted cautiously.¶ As a group, the five indices I tested contained attributes describing compositional diversity, coarse woody debris, regeneration, large trees and hollow trees – these were attributes that I also identified as core ones. However, unlike these indices, I quantified weeds indirectly through their effect on indigenous plant diversity, I included the contribution of non-indigenous species to vegetation cover and did not apply a discount to this contribution, I limited the direct assessment of regeneration to long-lived overstorey species, I used stand basal area as a surrogate for canopy cover, I quantified litter in terms of biomass (dry weight) rather than cover, and I included the additional attributes of quadratic mean diameter and the number of dead trees.¶ I also concluded that Parkes et al. (2003), Oliver and Parkes (2003), and Gibbons et al. (2004), misapplied the concept of benchmarking, by characterising attributes in terms of a benchmark range or average level. This ignored processes that underpin variation at the stand level, such as the increased development of some attributes at particular successional stages, and the fact that attributes can respond differently to disturbance agents. It also produced indices that were not particularly sensitive to the differences in attribute levels occurring between stands. I suggested that a more appropriate application of benchmarking would be at the overarching level of stand structural complexity, using a metric such as the index developed in this thesis. These benchmarks could reflect observed levels of structural complexity in unmodified natural stands at different successional stages, or thresholds for structural complexity at which a wide range of biota are present, and would define useful goals for guiding on-ground management.

The vegetation of the Sydney Basin, Australia, is highly flammable and subject to a wide range of fire regimes. Sclerophyllous shrubs and sedges are common and in some vegetation types up to 70 % of fuel consumed during a fire can be live. Research into fire behaviour and fuel dynamics has been minimal. To address this issue this thesis investigated the principal factor affecting the ease of ignition and rate of combustion of individual fuel particles and fuel beds in bushfires: dead fine fuel moisture (FFM). Two common Sydney Basin vegetation types, eucalypt woodland and heathland, each with a history of problematic fire management, were measured in the field for diurnal fluctuations in FFM following rain, under conditions similar to when prescribed burns are conducted. The FFM components of current operational fire behaviour models were found to be inadequate for predictions of FFM and fire behaviour under these conditions. The equilibrium moisture content (EMC) of five fuel types from the field site was investigated in a laboratory study. An existing function describing EMC as a function of temperature and relative humidity was evaluated and found to be very accurate for these fuels. Two FFM predictive models incorporating this function were evaluated on the field data and the laboratory results were shown to be applicable to the estimation of FFM in the field. One model gave very accurate predictions of FFM below fibre saturation point, but its accuracy was reduced when screen level conditions were used instead of those measured at fuel level. A recent process-based model that accounts for rainfall showed promise for predicting when fuel is < 25 % FFM. Systematic problems with the radiation budget of this model reduced the accuracy of predictions and further refinement is required. Live fine fuel moisture content (LFMC) of common heathland shrubs and sedge was investigated over two years and found to be both seasonal and influenced by phenology. LFMC minima occurred in late winter and spring (August to October), and maxima were in summer (December to February) when new growth was recorded. The dominant near-surface fuel in mature heath was sedge. It was found to have little seasonal variation in its??? percentage dead but the percentage dead maxima occured at the same time as the LFMC minima of shrubs and sedge in both years. Simple instantaneous models for duff moisture content in woodland and heathland and LFMC and the percentage dead sedge in heathland were developed. The information gained by this study will form the basis for future development of fuel moisture models for prescribed burning guidelines and fire spread models specific to the vegetation communities of the Sydney Basin.

Since the 1990’s Eucalyptus gomphocephala (tuart) has been suffering a significant decline in Yalgorup National Park, approximately 100 km south of Perth Western Australia. Symptoms range from chronic deterioration to sudden mass collapse. The role of Phytophthora pathogens was investigated because the progressive canopy thinning, dieback and heterogeneous distribution of the decline were similar to other forest declines caused by a range of Phytophthora species which are widespread throughout south-west Western Australia and worldwide. In combination with sampling for Phytophthora isolation, an initial diagnostic trial tested the effect of trunk applied phosphite, nutrients and combined phosphite and nutrients on natural stands of declining E. gomphocephala. Phosphite injection was used as a diagnostic tool to identify the possible role of Phytophthora pathogens because the chemical specifically suppresses Phytophthora pathogens and has no known direct fertilizer effect on the host. A range of nutrient treatments was also applied as a diagnostic tool to indicate what nutrient deficiencies may be involved in the decline. Initially no Phytophthora species were isolated from the treatment sites. However, individual and combined injection treatments of phosphite and nutrients improved the crown health over four years with the greatest improvement from treatments of phosphite and zinc sulphide. In combination with further rhizosphere sampling for Phytophthora species, the response of declining trees to phosphite application was further investigated in a second injection trial. Phosphite concentrations from 75 to 375 g phosphite/L improved crown health compared to the control, with the best improvement at 150 g phosphite/L. The positive response of declining trees to phosphite injection implicated a Phytophthora pathogen, despite no Phytophthora species being isolated at this time. Consequently further work was undertaken to determine the involvement of Phytophthora species. Concurrently to both injection trials, several seedling bioassays were conducted. The first bioassay tested the effect of pasteurising soil from a declining site within Yalgorup and healthy sites outside the Yalgorup woodland on E. gomphocephala seedlings grown ex situ. Seedling growth ex situ was not significantly reduced in nonpasteurised soil compared to the pasteurised soils from declining sites, and no Phytophthora species was isolated. To further investigate the disease the fine root and ectomycorrhizal systems of the largest main lateral root of 18 declining E. gomphocephala trees within Yalgorup were exposed using an air spade. Necrotic roots were sampled and the crown, fine root and ectomycorrhizal health were assessed. No Phytophthora species was isolated from necrotic roots; however, crown health of the declining trees was significantly correlated with the fine root and ectomycorrhizae density, suggesting that below ground damage could be involved in the decline. The relationship between the above and below ground health of the air spaded trees was investigated further using an in situ and ex situ seedling bioassay. In the in situ bioassay, seedlings were planted within the exposed root mats of the air spaded trees. In the ex situ bioassay, seedlings were grown within a glasshouse in pasteurised and non-pasteurised soil collected from the air spaded root mats. No Phytophthora species was identified in these bioassays, and seedlings grown ex situ in non-pasteurised soil showed no clear decline symptoms, but the health of the woodland trees was significantly correlated with seedling survival, foliar health and height of the seedlings An additional 32 sites throughout the E. gomphocephala range were sampled for the presence of Phytophthora pathogens using a modified sampling and isolation procedure. From this survey a new Phytophthora species was isolated from five sites from the roots of declining E. gomphocephala, E. marginata and Agonis flexuosa at Yalgorup National Park. Morphologically similar to P. citricola, the new Phytophthora species is unique based on phylogenetic analysis of the ITS and Cox1 gene regions and was named P. multivora. Phytophthora multivora has subsequently been isolated from all experimental sites showing tuart decline. Two experiments tested the pathogenicity of P. multivora to E. gomphocephala and E. marginata. The first experiment examined ex situ the pathogenicity of five P. multivora isolates and one P. cinnamomi isolate on the root systems of E. gomphocephala and one P. multivora isolate on the root system of E. marginata. In the second experiment, the pathogenicity of P. multivora to E. gomphocephala and E. marginata saplings was measured in situ using under-bark stem inoculation. Phytophthora multivora isolates caused significant fine root loss and lesion extension in under-bark inoculated stems of both E. gomphocephala and E. marginata. Phytophthora multivora was also reisolated from necrotic fine roots and lesions of inoculated saplings of both E. gomphocephala and E. marginata, thus satisfying Koch’s postulates. No seedlings died in these pathogenicity trials and P. multivora was not reisolated from beyond the fine roots. There was evidence that P. multivora significantly contributes to E. gomphocephala decline by episodically causing fine root damage leading to chronic deterioration of the trees.

Tall tuart (Eucalyptus gomphocephala) trees are a defining element of the landscape of Perth and the coastal plain to the north and south. However, with the health of some tuart stands deteriorating, most notably at Yalgorup south of Perth, concerns are heightening that the already fragmented tuart ecosystem will continue to contract, leaving a cultural and ecological scar in the landscape. Like many other eucalypt ecosystems, tuart woodlands have had a long association with fire and are believed to have been frequently burnt by the Aborigines prior to European settlement. Today, fragmentation and European land management practices have led to a lower frequency of fire across most remaining woodlands, but also episodes of intense fire at shorter intervals in some areas. Individual fire events as well as fire regimes have the potential to shape the structure, composition and extent of ecosystems, and eucalypt ecosystems are no different. Thus, the impact of fire and fire regimes on tuart health and regeneration was investigated in this study. A survey of the woodlands at Yalgorup revealed tuart decline was present across a range of sites with contrasting fire histories. Tuart health was poorest at the longest unburnt site (35 years) and the site burnt by frequent wildfire (three fires in 13 years), suggesting these extreme fire regimes had played a role in the decline. Nevertheless, low ratings of tree health at sites burnt approximately once per decade, point to factors other than fire playing a role in the decline of tuart at Yalgorup. The tuart populations at Yalgorup were dominated by individuals in larger size-classes and there was a significant negative relationship between tree size and the probability of tree mortality. In one stand in Yalgorup National Park, 38 % of the tuart saplings/trees had died. It follows that the regeneration and development of tuart seedlings into adults will need to occur within the next one to two decades if these woodlands are to persist. Seedling counts confirmed that tuart regeneration was virtually absent in unburnt areas, as is common with eucalypt species. Interpretations of size-class distributions suggested controlled burning contributed little to recruitment, whereas in areas subject to wildfire outside Yalgorup, tuart had regenerated in abundance such that size-class distributions were skewed towards the smaller size-classes. A repeat survey of plots established in 1976 supported anecdotal reports that the mid-storey tree peppermint (Agonis flexuosa) was increasing in density and height in Yalgorup. The skew towards the smallest size-class within peppermint populations at Yalgorup and the presence of seedlings ( > 200 seedlings ha-1) within areas not recently burnt (at least four years since fire) brought into focus the differing mode of regeneration for this species in comparison to tuart. In further contrast to tuart, mature peppermints were in good health with no dead trees reported in the population surveys. A possible role for competition in tuart decline was highlighted by significant negative correlation between peppermint density and tuart health. Together, these results suggest that a general drift from tuart woodland to peppermint forest appears entrenched. Comparative studies of the bark thickness, fire response and resprouting behaviour of tuart and peppermint illustrated the capacity of individuals of both species to persist with recurrent fire. As adults or juveniles, tuart and peppermint resprouted following complete canopy scorch, and often from crown branches: an ability not uncommon for co-occurring tree species and shrubs in this environment. Survival was between 75 and 100 % for fully-scorched tuarts in size-classes ranging from small saplings to trees across six sites. From the small sample of peppermints available for comparison, seedlings and small saplings appeared to be more vulnerable to mortality by fire; only 45 % of individuals with a diameter at breast height ¡Ü 1 cm survived following complete canopy scorch from a controlled burn. With thicker bark, a reliance on stem epicormic buds rather than a lignotuber for resprouting and a greater capacity for height growth, the fire resistance and post-fire recovery of tuart would be expected to differ from that for peppermint. Opportunities for managers to exploit these differences in their burning prescriptions so as to address the drift from tuart to peppermint dominance were outlined. In addition, results indicating a positive response in canopy condition for tuarts with < 10 % canopy scorch following a controlled burn imply that tuart vigour may benefit more immediately from fire. But, observations also revealed that spikes in intensity within controlled burns can damage large unhealthy trees and thereby accelerate the decline process. Thus, the application of fire to declining tuart stands needs to be conducted skillfully. Patterns of growth and survival for tuart and peppermint seedlings were linked to the contrasting ability of the species to establish at burnt and unburnt sites. The purported importance of ashbeds in tuart establishment was demonstrated; at the end of summer (February) at a recently burnt site (Golden Bay), the mean height of tuart seedlings on ashbeds was three times that for those off ashbeds, and the survival rate on and off the ashbeds was 35 % and 15 %, respectively. Therefore, while important, tuart seedlings were not dependent on ashbeds in this instance. The hardy nature of peppermint seedlings when compared to tuart was illustrated when the species were planted in an unburnt area of tuart-peppermint woodland at Yalgorup; nine months after planting, 38 % of the peppermint seedlings survived while only 9 % of the tuart survived. Most of the mortality was linked with the summer-drought period and it was suspected that peppermint seedlings were more drought tolerant. A complementary glasshouse experiment showed that tuart had a greater shoot:root ratio than peppermint, which may be one factor in the greater sensitivity of this species to drought. Further, this experiment revealed that with an increase in nutrient supply, the proportional increment in rooting depth for tuart (1.6 times) was significantly greater than for peppermint (0.3 times). An increased availability of nutrients in ashbeds following fire, particularly for phosphorous, was measured within tuart woodland. Therefore, it was inferred that the availability of nutrients was a critical factor increasing the growth, rooting depth and consequently the greater survival of tuarts on ashbeds. Overall, tuart was concluded to share the Competitor strategy (after Grime) in common with many other eucalypts: rapid growth and the attainment of a large size. On the other hand, peppermint exhibits some of the traits of the Stress Tolerator strategy (after Grime): low minimum resource requirements for growth and survival. The consequence of the increasing cover of peppermint on tuart establishment was explored in field experiments with planted tuart seedlings. No significant impact on seedling growth or survival was observed. There was a declining trend in the seedling growth rates under the high compared to the low peppermint density treatments as the second summer of the experiment was approached, although a statistical difference could not be shown. Peppermint density also had no significant influence on damage to the seedlings from insect attack or the foliar pathogen Mycosphaerella cryptica. Overall, insects and M. cryptica had only an incidental impact on the seedlings: the mean level of canopy damage per affected seedling was < 10 % for either of these two damage agents. Soil type, specifically whether growth occurred on an ashbed was demonstrated to be the most important factor in tuart growth and survival in the 18 months following planting. Although survival was superior on ashbeds (88 %), mean survival was > 50 % in unburnt soil 18 months after planting indicating the potential for restorative plantings to occur in some woodlands between fires. Tuart decline, and the role of altered fire regimes in the decline is complex and further avenues of research were emphasized. Nevertheless, the findings of this and other studies are sufficient to enable purposeful actions to conserve and restore tuart woodlands; recommendations regarding the application of fire with a view to these goals are presented in the final discussion.

The patterns of spatial distribution and abundance were investigated for moth assemblages in the eucalypt woodlands of the Sydney Basin. A total of 228 species of Lepidoptera, distributed among 25 families, were recorded from three national parks located on the perimeter of the Sydney metropolitan region.From within the eucalypt woodland habitat of the Sydney Basin, the study investigated the spatial variation of night-flying Lepidoptera present at several different scales of observation, from the trap level through to across the landscape. Assemblages varied with spatial scale, with uniformity occurring across the landscape as a whole, however becoming patchy at finer spatial scales. Multivariate and turnover analysis indicated that although heterogeneity of abundance and richness may vary significantly depending on spatial scale, sites and national parks contained their own unique suite of species in comparison to one another.The structure of the assemblages of moths in the eucalypt woodlands of the Sydney Basin can vary, and is dependant on the level of spatial scale of observation. Further study needs to be conducted at a range of temporal scales to ascertain the presence of patterns in the Lepidoptera communities in the Sydney region in order to contribute to the development of suitable conservation strategies in the Sydney Basin.

Resumo: O Eucalyptus urophylla destaca-se pelo potencial de utilização de sua madeira, pela sua plasticidade de adaptação a diferentes condições ambientais brasileiras e por ser tolerante ao cancro do eucalipto (Cryphonectria cubensis). A utilização de sementes melhoradas se faz necessária, considerando o iminente déficit florestal que começou no Brasil, a partir de 2004, em função da demanda por madeira ser maior que a sua oferta. Entretanto, o melhoramento dessa espécie, no Brasil, depende da existência de variabilidade genética das populações introduzidas, a qual evita a ocorrência de depressão endogâmica. O presente trabalho visa o estudo genético de uma população base de E. urophylla, originária de Flores e Timor, e instalada em Selvíria-MS. Estudou - se a variabilidade genética dessa população através de análises quantitativas. Dessa forma, os objetivos específicos do estudo foram: a) estimar a variabilidade genética para os principais caracteres silviculturais; b) estimar possíveis ganhos na seleção, utilizando-se da seleção entre e dentro de progênies e do Índice Multi-efeitos, analisando o efeito do desbaste em uma população base de E. urophylla. O experimento foi instalado em 17 de março de 1992, na Fazenda de Ensino, Pesquisa e Extensão da Faculdade de Engenharia, Campus de Ilha Solteira (FE/UNESP), localizada no município de Selvíria - MS. O teste de progênies foi instalado obedecendo a um delineamento experimental em Látice 8x8, quíntuplo, parcialmente balanceado, com 64 progênies provenientes da Estação Experimental do Instituto de Pesquisas e Estudos Florestais (IPEF/ESALQ/USP), localizada no município de Anhembi - S.P. As parcelas contêm oito árvores, no espaçamento de 3,0 x 3,0 metros. Os caracteres quantitativos avaliados e analisados foram: 1- diâmetro à altura do peito (DAP); 2- altura total da planta (H); 3- tipo de ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The Eucalyptus urophylla is detached for its wood potential of utilization for its plasticity of plasticity of adaptation in different Brazilian's environmental conditions and for being tolerant towards the eucalyptus canker (Cryphonectria cubensis). The utilization of improved seeds is needed, considering the imminent woodland's deficit that started in Brazil, in 2004, since the heavy Wood demand was higher than it offers. However the improvements of this specie in Brazil, depends on the existence of genetic variability of the installed populations, which avoids the occurrence of endogamous depression. The present report aims at the genetic study of a base population of E. urophylla, originated from Flores e Timor, and installed in Selvíria-MS. Its genetic variability was studied through quantitative analysis. This way, the specific objectives of this report was: a) Guess the genetic variability for the main silvicultural characters; b) Guess possible earnings in the selection, utilizing this selection among and inside the progenies and inside the progenies and the index of multi-effects, analyzing the skive effect in a base population of E. urophylla. The experiment was installed on March 17th of 1992, on the engineering university's farm of teaching, researches, and extension, campus in Ilha Solteira (FE/UNESP), located in Selvíria - MS. The progenies test was installed obeying an experimental delineation in lattice of 8x8, quintuplet, partially balanced with 64 progenies which came from the experimental station in the woodland's institute of researches and studies, (IPEF/ESALQ/USP), located in of Anhembi - SP. The parcels have 8 trees, in a space of 3,0 x 3,0 meters. The evaluated and analyzed quantitative characters was: 1-Diameter at chest's height (DAP); 2-Total plant's height (H); 3-Kind of bark (CAS); 4- Shape of the shank (FOR); 5- Bifurcation; 6- Survival (SOBR) ... (Complete abstract click electronic access below)
Orientador: Miguel Luiz Menezes Freitas
Coorientador: Mario Luiz Teixeira de Moraes
Banca: Pedro Cesar dos Santos
Banca: Ananda Virgínia de Aguiar
Mestre

The floristic survey and analysis of 100 plots in pure salmon gum woodland in the Great Western Woodlands (GWW) region of Western Australia contributed to the classification of salmon gum communities across south–western Australia. Gradients in annual mean rainfall and temperature, and seasonal rainfall patterns influence the floristic patterns and delineation of five range-wide communities. Strong differences were detected between Wheatbelt and GWW communities, confirming the threatened status of the Wheatbelt salmon gum woodlands.

Grazing by livestock has led to passive clearing of the majority of remaining areas of native vegetation on farmland (remnants) in the Collie river catchment in the south-west of Western Australia. Livestock grazing in these areas removes most of the understorey and prevents recruitment. This thesis documents the impact of livestock grazing on the vegetation dynamics of these remnants through changes to floristics and structure and effects on the soil. It also looks at the possibility of rehabilitation of degraded areas by assessing seed reserves in the soil seedbank and the regeneration of species with the exclusion of grazing. A review of the literature provided a background to this study and looks at the broader issues of the significance of remnants of native vegetation as well as the ecology of disturbance in terms of vegetation response and resilience and deals with the problems of management. Species diversity and richness have decreased with increased grazing intensity and these were negatively correlated with proportion of exotic species. Site ordination of a large sample of remnants placed sites in two major groups based on grazing intensity, with position of sites influenced by proportion of exotic species, proportion of perennial herbs and shrubs and species diversity and richness. Cover and abundance of native perennial species decreased, but increased for exotic annual species with a gradient of response between heavily grazed, lightly grazed and ungrazed sites. Other life form groups such as native annuals, geophytes and native grasses were not significantly affected by grazing. Perennial species that are able to resprout from an underground storage organ as well as germinate readily from seed appear the most resilient to grazing disturbance. Effects of grazing disturbance on the soil included increased surface soil compaction and water repellency as well as significant increases in concentrations of soil nutrients, particularly N and P. Age structure of overstorey species indicated that there has been a lack of recruitment at the heavily grazed sites for some time. Germination of overstorey species took place each year of the study but mortality of seedlings was high, with no seedlings surviving after one summer at the heavily grazed sites. Experiments on the soil seedbank showed a dominance of seed from exotic annual species and a lack of seed from native perennial species within the heavily grazed sites, indicating that natural regeneration is unlikely from this source. Heat treatment of soil samples showed a decrease in germination of exotic species and an increase in the germination of native species. After l to 3 years there was a significant increase in number and cover of native perennial species in exclosure plots, mainly from resprouting. The greatest increase in cover in exclosures was seen for native perennial grasses, while abundance of exotic annuals did not increase significantly compared to adjacent open plots. Time series ordination showed the movement of exclosure plots towards the ungrazed plots after three years, indicating the increase in floristic similarity between the exclosures and the ungrazed plots. This study has shown that grazing has resulted in a shift from a community dominated by native perennial species to one dominated by exotic annual species. High grazing intensity and short grazing history, climatic variability and effects on the soil are the major factors affecting the observed ·responses of the vegetation to grazing. Natural regeneration in degraded remnants is possible if livestock are excluded. Rehabilitation of some sites is also required and a procedure is suggested.

An increasing number of Australians want to be assured that the food and fibre being produced on this continent have been grown and harvested in an ecologically sustainable way. Ecologically sustainable farming conserves the array of species that are integral to key ecological processes such as pollination, seed dispersal, natural pest control and the decomposition of waste. Wildlife Conservation in Farm Landscapes communicates new scientific information about best practice ways to integrate conservation and agriculture in the temperate eucalypt woodland belt of eastern Australia. It is based on the large body of scientific literature in this field, as well as long-term studies at 790 permanent sites on over 290 farms extending throughout Victoria, New South Wales and south-east Queensland. Richly illustrated, with chapters on birds, mammals, reptiles, invertebrates and plants, this book illustrates how management interventions can promote nature conservation and what practices have the greatest benefit for biodiversity. Together the new insights in this book inform whole-of-farm planning. Wildlife Conservation in Farm Landscapes is an ideal resource for land managers and farmers interested in integrating farming and environmental values and anyone interested in biodiversity in woodlands and agricultural zones. Recipient of a 2017 Whitley Awards Certificate of Commendation for Conservation in Action

In eastern Australia, grassy eucalypt woodlands have been under severe pressure from agricultural development, with problems of land degradation and species decline being most severe in the cropping lands of south-eastern Australia. Managing and Conserving Grassy Woodlands describes a set of principles that will enable landholders to maintain or increase productivity without compromising ecological sustainability, and at the same time maintaining a substantial proportion of the native flora and fauna. The book provides the technical foundations underpinning the principles and explains the importance of planning at a landscape scale. Each major principle is addressed in a separate chapter which explains the scientific understanding behind the principle and which discusses some of the issues relating to its practical application. Additional chapters outline the basic ecological concepts underpinning the principles and the responses of landholders who have had the opportunity to discuss and reflect on the principles. For those interested in translating the principles into a property plan, a final chapter explores the steps that can be taken. Managing and Conserving Grassy Woodlands is intended for those at the interface of disciplinary research and on-ground application, whether they are working in research, regional planning, extension, landcare or land management.

The river red gum has the most widespread natural distribution of Eucalyptus in Australia, forming extensive forests and woodlands in south-eastern Australia and providing the structural and functional elements of important floodplain and wetland ecosystems. Along ephemeral creeks in the arid Centre it exists as narrow corridors, providing vital refugia for biodiversity. The tree has played a central role in the tension between economy, society and environment and has been the subject of enquiries over its conservation, use and management. Despite this, we know remarkably little about the ecology and life history of the river red gum: its longevity; how deep its roots go; what proportion of its seedlings survive to adulthood; and the diversity of organisms associated with it. More recently we have begun to move from a culture of exploitation of river red gum forests and woodlands to one of conservation and sustainable use. In Flooded Forest and Desert Creek, the author traces this shift through the rise of a collective environmental consciousness, in part articulated through the depiction of river red gums and inland floodplains in art, literature and the media.

What are the 10 key issues that must be addressed urgently to improve Australia's environment? In this follow up to the highly successful book Ten Commitments: Reshaping the Lucky Country's Environment, Australia’s leading environmental thinkers have written provocative chapters on what must be done to tackle Australia's environmental problems – in terms of policies, on-ground actions and research. Each chapter begins with a brief overview of the 10 key tasks that need to be addressed in a given field, and then each issue is discussed in more detail. Chapters are grouped into ecosystems, sectors and cross-cutting themes. Topics include: deserts, rangelands, temperate eucalypt woodlands, tropical savanna landscapes, urban settlements, forestry management , tropical and temperate marine ecosystems, tropical rainforests, alpine ecosystems, freshwater ecosystems, coasts, islands, soils, fisheries, agriculture, mining, grazing, tourism, industry and manufacturing, protected areas, Indigenous land and sea management, climate change, water, biodiversity, population, human health, fire, energy and more. Ten Commitments Revisited is a must read for politicians, policy makers, decision makers, practitioners and others with an interest in Australia’s environment.