Journal articles on the topic 'Eucalyptus tetrodonta'
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1
Setterfield, S., and RJ Williams. "Patterns of Flowering and Seed Production in Eucalyptus miniata and E. tetrodonta in a Tropical Savanna Woodland, Northern Australia." Australian Journal of Botany 44, no. 2 (1996): 107. http://dx.doi.org/10.1071/bt9960107.
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The reproductive phenology-the annual and spatial variation in tree fecundity, ovule development and seedfall-of Eucalyptus miniata Cunn. ex Schauer and E. tetrodonta F. Muell. is described at a tropical savanna site in northern Australia from 1992 to 1994. There was substantial inter-annual variability in fecundity of both species at the individual and the population level. The proportion of ovules which survived did not vary significantly between years. Seed production and seedfall varied substantially between years with large seed yields in 1994 and low seed yields in 1993. Eucalyptus miniata and E. tetrodonta are separated in time (by 2-8 weeks) with respect to peak periods for all key phenology events-budding, flowering and seedfall. Both species are non-serotinous with all seed shed within 8 months of ovule initiation. Peak seedfall occurred up to 1 month before the first wet season rains for E. miniata and coincided with these rains for E. tetrodonta. Post-dispersal conditions for germination and establishment are more likely than seed supply to limit seedling establishment of E. miniata and E. tetrodonta.
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Bowman, DMJS, and WJ Panton. "Differences in the Stand Structure of Eucalyptus tetrodonta Forests Between Elcho Island and Gunn-Point, Northern Australia." Australian Journal of Botany 41, no. 2 (1993): 211. http://dx.doi.org/10.1071/bt9930211.
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Eucalyptus tetrodonta dominated open forests occur across the northern coast of the Northern Territory. They typically have a well developed grass understorey, scattered saplings, numerous woody sprouts (ramets) and a conspicuous absence of seedlings (genets). We compared a typical E. tetrodonta stand on Gunn Point with an atypical stand on Elcho Island; the forest on Elcho Island had less grass cover, greater canopy and litter cover, a deeper organic layer and higher densities of seedlings, woody sprouts and saplings than on Gunn Point. Gunn Point had a greater number of large E. tetrodonta trees that were more widely spaced than trees on Elcho Island. The cause of these differences remains unclear.
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Eamus, D., CA Berryman, and GA Duff. "The Impact of CO2 Enrichment on Water Relations in Maranthes corymbosa and Eucalyptus tetrodonta." Australian Journal of Botany 43, no. 3 (1995): 273. http://dx.doi.org/10.1071/bt9950273.
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Seeds of Maranthes corymbosa Blume and Eucalyptus tetrodonta F.Muell were sown under ambient or CO2 enriched conditions (two replicate tents per treatment) in tropical Australia and allowed to grow, rooted in the ground, for 20 months. For both species, periodic measurements of leaf water potential, stomatal conductance and leaf temperature were made on four replicate leaves on each of four replicate trees within each tent. Measurements were made in November (M. corymbosa) and June (E. tetrodonta). At the same time, atmospheric wet and dry bulb temperatures were recorded and hence leaf-to-air vapour presure difference (LAVPD) calculated. Measurements of pre-dawn leaf water potential were also made on E. tetrodonta. Leaves were also taken to the laboratory, rehydrated to full turgor and pressure-volume analyses undertaken. For M. corymbosa, leaf water potential was lower throughout the day for control leaves compared to leaves growing in CO2 enriched air. Similarly, pre dawn leaf water potential was lower for control E. tetrodonta trees than for trees grown with CO2 enrichment. However, mid-morning and mid-afternoon values of leaf water potential for E. tetrodonta were slightly lower for plants growing in CO2 enriched air compared to control plants. In both species, stomatal conductance was consistently lower for trees grown in CO2 enriched air than for controls. Whole plant hydraulic conductivity of both species was significantly lower for trees grown in CO2 enriched air than for control trees. For both species, maximum turgor and bulk volumetric elastic modulus increased and osmotic potential at zero turgor decreased for trees grown in CO2 enriched air.
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Eamus, D., and L. D. Prior. "Seasonal Changes in Leaf Water Characteristics of Eucalyptus tetrodonta and Terminalia ferdinandiana Saplings in a Northern Australian Savanna." Australian Journal of Botany 47, no. 4 (1999): 587. http://dx.doi.org/10.1071/bt98014.
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The monsoonal areas of northern Australia experience extreme seasonal variations in rainfall, with an annual dry season of 7 months or more. Seasonal changes in leaf water relations were investigated for saplings of two tree species common in northern Australian savannas: Eucalyptus tetrodonta F.Muell, an evergreen, and Terminalia ferdinandiana Excell, which is deciduous. Saplings may experience more severe water stress than mature trees because their root systems are less extensive. This study found a positive correlation between pre-dawn leaf water potential and tree height during the dry season, but not during the wet season, for both E. tetrodonta and T. ferdinandiana trees. Pressure–volume curves were constructed for leaves of E. tetrodonta saplings at 2-monthly intervals throughout the year. Osmotic potential at full turgor decreased from a maximum of −1.33 MPa in February (wet season) to −2.25 MPa in October (late dry season), then increased to an intermediate value of −1.71 MPa in December (early wet season). Leaves of T. ferdinandiana saplings were compared in February (wet season) and April (end of wet season; before leaf senescence). Osmotic potential at full turgor decreased from −1.18 MPa in February to −1.39 MPa in April. The capacity for turgor maintenance was larger for E. tetrodonta than for T. ferdinandiana, with osmotic potential at full turgor and the turgor loss point, relative water content at the turgor loss point and the ratio of turgid weight to dry weight all lower in E. tetrodonta.
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O'Grady, A. P., X. Chen, D. Eamus, and L. B. Hutley. "Composition, leaf area index and standing biomass of eucalypt open forests near Darwin in the Northern Territory, Australia." Australian Journal of Botany 48, no. 5 (2000): 629. http://dx.doi.org/10.1071/bt99022.
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Savanna communities dominate the wet–dry tropical regions of the world and are an important community type in monsoonal northern Australia. As such they have a significant impact on the water and carbon balance of this region. Above the 1200-mm isohyet, savanna’s are dominated by Eucalyptus miniata–E. tetrodonta open forests. We have described in detail the composition and structure as well as seasonal patterns of leaf area index and above-ground biomass in the E. miniata–E. tetrodonta open forests of the Gunn Point region near Darwin in the Northern Territory of Australia. In all, 29 tree species from four phenological guilds were recorded in these forests. Stand structure suggests that the forests were still recovering from the impacts of cyclone Tracy and subsequent frequent fires. Eucalyptus miniata and E. tetrodonta were significant contributors to overstorey leaf area index and standing biomass (>70%), and both leaf area index and biomass were strongly correlated to basal area. Leaf area index was at a maximum (about 1.0) at the end of the wet season and declined over the dry season by about 30–40%. There were proportionally greater changes in the understorey reflecting the greater contribution of deciduous and semi-deciduous species in this strata. Standing biomass was about 55 t ha –1 . Detailed descriptions of leaf area index and biomass are important inputs into the development of a water and carbon balance for the savanna’s of northern Australia.
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Werner, Patricia A., and Peter G. Murphy. "Size-specific biomass allocation and water content of above- and below-ground components of three Eucalyptus species in a northern Australian savanna." Australian Journal of Botany 49, no. 2 (2001): 155. http://dx.doi.org/10.1071/bt99026.
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The biomass of component parts of individuals of three dominant canopy tree species in the northern savannas of Australia was determined from field populations in World Heritage Kakadu National Park. Forty individual trees of Eucalyptus tetrodonta F. Muell., E. miniata Cunn. ex Schauer and E. papuana F.Muell., representing a range in size from 4 to 50 cm diameter at breast height (DBH), were felled for dry biomass of leaves, branches, woody stems and bark. Forty-seven other trees of E. tetrodonta and E. miniata were excavated for belowground biomass, by using trenching methods. The average proportion of aboveground biomass in foliage was 3–5%, to branches 20–32%, and trunk wood 77–59%, with little change over the size of a tree. Water content of foliage decreased with size of tree in all species, indicating an increasing xeromorphy as the trees age. Gross morphology of roots was bimorphic, with 70% of biomass at <20-cm soil depth, and large roots running horizontally on top of the shallow (0.3–1.4 m) ferricrete layer. There was no evidence of roots having access to water below this layer. Patterns of heights, percentage biomass allocation, percentage water content, and bark thickness of the three species were consistent with the rank order of their distributions across a topographic gradient, reflecting relative capacities to withstand drought, belowground competition and fire. By using tree diameter as the independent variable (x in cm DBH), allometric relationships were calculated to provide a method for calculating growth and productivity by using non-destructive repeat measures of sizes of trees. The total aboveground biomass (y in kg) of individual trees is y = 0.2068x2.3191 for E. tetrodonta, y = 0.1527x2.390 for E. miniata and y = 0.0356x2.8567 for E. papuana. Total belowground biomass per tree for E. tetrodonta is y = 31.150e0.0601x and for E. miniata, y = 28.753e0.0644x. As a tree grows, the aboveground biomass increases as a power function and belowground biomass as an exponential function of DBH, producing a decreasing proportion of total biomass below ground, e.g. the root/shoot ratio of E. tetrodonta is 0.50 for trees <10 cm DBH, 0.40 for trees 20 cm DBH, and 0.25 for trees 40–55 cm DBH. The overall proportion of total biomass below ground in Kakadu is well below 50%, contrary to the commonly accepted notion that the majority of biomass in savannas is below ground.
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Janos, David P., John Scott, Catalina Aristizábal, and David M. J. S. Bowman. "Arbuscular-Mycorrhizal Networks Inhibit Eucalyptus tetrodonta Seedlings in Rain Forest Soil Microcosms." PLoS ONE 8, no. 2 (February 27, 2013): e57716. http://dx.doi.org/10.1371/journal.pone.0057716.
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Reddell, Paul, Victoria Gordon, and Michael S. Hopkins. "Ectomycorrhizas in Eucalyptus tetrodonta and E. miniata Forest Communities in Tropical Northern Australia and their Role in the Rehabilitation of these Forests Following Mining." Australian Journal of Botany 47, no. 6 (1999): 881. http://dx.doi.org/10.1071/bt97126.
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The importance of ectomycorrhizas in Eucalyptus tetrodonta F.Muell. and E. miniata Cunn. ex Schauer dominated forests and woodland communities in the monsoonal tropics of northern Australia was assessed. Ectomycorrhizas colonised between 24 and 54% of final order lateral roots in soil cores collected at 16 native forest sites. Only a minority of the plant species present formed ectomycorrhizas (mainly eucalypts and acacias) but these species contributed more than 75% of the basal area. More than 70 species of putative ectomycorrhizal fungi were collected, with three hypogeous taxa (Nothocastoreum, Hysterangium and an undescribed Boletaceae) most frequently encountered. Glasshouse inoculation experiments confirmed that a diverse range of fungi was capable of forming ectomycorrhizas with E. tetrodonta and E. miniata seedlings, and that the growth of both species could be substantially increased by inoculation with specific fungi. The fungi most effective in increasing seedling growth were generally those which most extensively colonised the seedling roots. A second component of this study investigated the requirements for ectomycorrhizal fungi in native forest rehabilitation following mining. Ectomycorrhizal infectivity was low in disturbed soils and mine spoil materials, with the intensity of disturbance and the presence of regrowth vegetation key determinants of the level of infectivity. Inoculation of seedlings of E. miniata with spores of ectomycorrhizal fungi increased both growth and leaf phosphorus concentrations by between two- and three-fold at 7 months after planting out on a waste rock dump devoid of native ectomycorrhizal propagules. The application of these findings to minesite rehabilitation in the region, and the feasibility of using spores for broad-scale inoculation, are discussed.
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BOWMAN, DAVID M. J. S., DONALD C. FRANKLIN, OWEN F. PRICE, and BARRY W. BROOK. "Land management affects grass biomass in the Eucalyptus tetrodonta savannas of monsoonal Australia." Austral Ecology 32, no. 4 (June 2007): 446–52. http://dx.doi.org/10.1111/j.1442-9993.2007.01713.x.
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Janos, David P., John Scott, and David M. J. S. Bowman. "Temporal and spatial variation of fine roots in a northern Australian Eucalyptus tetrodonta savanna." Journal of Tropical Ecology 24, no. 2 (March 2008): 177–88. http://dx.doi.org/10.1017/s0266467408004860.
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Abstract:Six rhizotrons in an Eucalyptus tetrodonta savanna revealed seasonal changes in the abundance of fine roots (≤ 5 mm diameter). Fine roots were almost completely absent from the upper 1 m of soil during the dry season, but proliferated after the onset of wet-season rains. At peak abundance of 3.9 kg m−2 soil surface, fine roots were distributed relatively uniformly throughout 1 m depth, in contrast with many tropical savannas and tropical dry forests in which fine roots are most abundant near the soil surface. After 98% of cumulative annual rainfall had been received, fine roots began to disappear rapidly, such that 76 d later, less than 5.8% of peak abundance remained. The scarcity of fine roots in the upper 1 m of soil early in the dry season suggests that evergreen trees may be able to extract water from below 1 m throughout the dry season. Persistent deep roots together with abundant fine roots in the upper 1 m of soil during the wet season constitute a ‘dual’ root system. Deep roots might buffer atmospheric CO2 against increase by sequestering carbon at depth in the soil.
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Wilson, B. A., and D. M. J. S. Bowman. "Factors influencing tree growth in tropical savanna: studies of an abrupt Eucalyptus boundary at Yapilika, Melville Island, northern Australia." Journal of Tropical Ecology 10, no. 1 (February 1994): 103–20. http://dx.doi.org/10.1017/s0266467400007756.
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ABSTRACTMost of the land surface of Melville Island, Australia's second largest island, is covered in Eucalyptus savanna. One exception is an area at Yapilika where a large tract of savanna is dominated by Acacia shrubs. An ordination analysis of 122 quadrats revealed that the boundary of Eucalyptus dominance did not correspond to a major change in floristic composition. Detailed transect studies at one site on the boundary showed that Eucalyptus trees were abruptly replaced by a band of Grevillea trees which gradually gave way to Acacia shrub dominance. There was a gradual change in the floristic composition of the savanna across the boundary. The distributional limit of Eucalyptus was found to be independent of any hydrological discontinuity. There was a slight decrease (<2.5 m) in altitude from Eucalyptus to Acacia savanna. The Acacia savanna soils were sandier and their surface soil had significantly lower concentrations of Ca and Mg and significantly greater concentration of Al compared with the Eucalyptus savanna soils. Eucalyptus seedlings planted in the three savanna communities were not found to be under drought stress (pre-dawn leaf xylem potentials of > – 0.9 MPa) during the dry season. Over a 12 month period Eucalyptus tetrodonta and E. miniata seedling growth was not significantly different on the Acacia or Eucalyptus savanna, although this result may be due to the counteracting effects of greater soil fertility and tree competition in the Eucalyptus savanna and lower soil fertility in the treeless, and hence competition-free, Acacia savanna. This hypothesis is supported by the significantly greater growth of Eucalyptus seedlings on fertilized Acacia savanna soils. The limited production, dispersal and establishment of Eucalyptus seeds and the greater frequency of fires in the Acacia savanna probably explains the abrupt limit to Eucalyptus dominance along the edaphic gradient.
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Nolan, Lisa. "Bark paintings conservation: Eucalyptus tetrodonta properties, bark harvesting and various mounting systems in the Northern Territory." AICCM Bulletin 39, no. 2 (July 3, 2018): 96–106. http://dx.doi.org/10.1080/10344233.2018.1491090.
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BOWMAN, D. M. J. S., and W. J. PANTON. "Munmarlary revisited: Response of a north Australian Eucalyptus tetrodonta savanna protected from fire for 20 years." Austral Ecology 20, no. 4 (December 1995): 526–31. http://dx.doi.org/10.1111/j.1442-9993.1995.tb00571.x.
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C. Z. Woinarski, John, Greg Connors, and Don C. Franklin. "Thinking honeyeater: nectar maps for the Northern Territory, Australia." Pacific Conservation Biology 6, no. 1 (2000): 61. http://dx.doi.org/10.1071/pc000061.
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We create monthly maps of nectar availability for the 1.4 x 106 km2 jurisdiction of the Northern Territory, Australia. These are based on a combination of vegetation mapping and a series of indices of plant species specific nectar scoring. The maps reveal complex spatial and temporal variation in nectar availability, but most notably a greater nectar resource in the monsoon-influenced north than in the arid south, and a peak in nectar availability in the dry season. The latter is associated with the extensive tropical eucalypt forests (especially those co-dominated by Eucalyptus miniata and E. tetrodonta). In contrast, wet season nectar availability in these forests is limited, but riparian and swampland forests, typically dominated by Melaleuca species, provide rich but spatially restricted nectar resources. The extensive and rich nectar resources available in eucalypt forests in the dry season supplement the diets of many species which are not primarily nectarivorous. This resource helps shape the singularity of northern Australian eucalypt forests relative to other extensive forests elsewhere in the world. Nectarivores remain in the system through a combination of movements across a number of scales, habitat shifting, and diet shifting. The latter is aided by the peaking of invertebrate and fruit resources at the times of minimum nectar production; a shuffling in resource availability brought about by the extreme climatic seasonality.
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Prior, L. D., D. Eamus, and G. A. Duff. "Seasonal and Diurnal Patterns of Carbon Assimilation, Stomatal Conductance and Leaf Water Potential in Eucalyptus tetrodonta Saplings in a Wet - Dry Savanna in Northern Australia." Australian Journal of Botany 45, no. 2 (1997): 241. http://dx.doi.org/10.1071/bt96017.
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Seasonal and diurnal trends in carbon assimilation, stomatal conductance and leaf water potential were studied using 1–3 m tall saplings of Eucalyptus tetrodonta (F.Muell.). The study site was in an unburnt savanna near Darwin, where rainfall is strongly seasonal. Mean daily maximum assimilation rates ranged from 14.5 µmol m-2 s-1 in May to 4.8 µmol m-2 s-1 in October. There was a linear relationship between daily maximum assimilation rates and pre-dawn leaf water potential (r = 0.62, n = 508) and a log–log linear relationship between daily maximum stomatal conductance and pre-dawn leaf water potential (r = 0.68, n = 508). Assimilation rates and stomatal conductance were always higher in the morning than in the afternoon, irrespective of season. Stomatal conductance responded more strongly to leaf-to-air vapour pressure difference when pre-dawn leaf water potentials were moderately low (–0.5 to –1.5 MPa) than when they were very low (< –1.5 MPa) or high (> –0.5 MPa). Assimilation decreased sharply when temperature exceeded 35˚C. Seasonal trends in assimilation rate could be attributed primarily to stomatal closure, but diurnal trends could not. High leaf temperatures were a major cause of lower assimilation rates in the afternoon. Approximately 90% of leaves were lost by the end of the dry season, and above-ground growth was very slow. It is hypothesised that E. tetrodonta saplings allocate most photosynthate to root and lignotuber growth in order to tolerate seasonal drought and the high frequency of fire in northern Australian savannas.
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Williams, Richard J., and Michael Douglas. "Windthrow in a tropical savanna in Kakadu National Park, northern Australia." Journal of Tropical Ecology 11, no. 4 (November 1995): 547–58. http://dx.doi.org/10.1017/s026646740000910x.
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ABSTRACTWindthrow was assessed following a convective storm in a stand of tropical savanna in Kakadu National Park, northern Australia. Over an area of 3 ha, 79 out of 810 trees (9.8%) were damaged; 27 of them were either uprooted or snapped off at the trunk. Logistic regression showed that both species and tree height were significant determinants of the probability of wind damage. Branch loss and either uprooting or trunk snapping was highest in the canopy sub-dominant Eucalyptus porrecta. Damage was lowest in the sub-dominant trees Erythrophleum chlorostachys, a species which is relatively resistant to termite damage, and Terminalia ferdinandiana, a deciduous species which is generally shorter than the main canopy dominants. Damage was intermediate in the two most common canopy dominants, Eucalyptus tetrodonta and E. miniata. Wind damage was greatest in trees taller than 9 m and relatively minor in trees below this height. Wind disturbs savanna trees in a manner opposite to that of fire, because wind damage is greatest in taller trees, whereas fire damage is greatest in smaller trees. This, coupled with significant within-patch variability in the extent of wind damage, may act to increase small-scale environmental heterogeneity in savannas.
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Geyle, Hayley M., Leigh-Ann Woolley, Hugh F. Davies, John C. Z. Woinarski, and Brett P. Murphy. "Targeted sampling successfully detects the cryptic and declining arboreal marsupial (Phascogale pirata) in northern Australia." Pacific Conservation Biology 26, no. 4 (2020): 395. http://dx.doi.org/10.1071/pc20008.
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The threatened northern brush-tailed phascogale (Phascogale pirata) is one of the most poorly known mammals in Australia. While the few available records indicate a decline in its distribution and abundance, it has not previously been subject to intensive targeted survey. Here, we trialled a specifically tailored methodology for detection of P. pirata, with the aim of informing ongoing survey and monitoring of this species. We deployed 50 motion-sensor cameras (spaced closely together in a grid 500×1000m) on Melville Island (Northern Territory, Australia), between June 2018 and May 2019. Cameras were baited and secured to trees ~3m above the ground on a bracket facing the trunk. We selected for large (>30cm diameter at breast height [DBH]) trunks of the dominant tree species (Eucalyptus miniata, E. tetrodonta and Corymbia nesophila). We detected P. pirata 16 times on eight cameras over the duration of the study, finding that detection was most likely on large (DBH >41.5cm) E. tetrodonta trees during the wet season. Our results indicate that survey effort for this species should be seasonally targeted and focussed on large trees. However, the efficacy of additional methods (nest boxes, Elliott traps) and a comparison between detections on arboreal versus ground-based cameras requires further investigation. We highlight the importance of conducting additional work on this species, as little is known about its ecology, population trends and threats, making it difficult to assess its conservation status. Without more targeted work, P. pirata is at risk of slipping into extinction unnoticed.
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Prior, L. D., D. Eamus, and G. A. Duff. "Seasonal Trends in Carbon Assimilation, Stomatal Conductance, Pre-dawn Leaf Water Potential and Growth in Terminalia ferdinandiana, a Deciduous Tree of Northern Australian Savannas." Australian Journal of Botany 45, no. 1 (1997): 53. http://dx.doi.org/10.1071/bt96065.
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Seasonal trends in pre-dawn leaf water potential and morning and afternoon rates of light-saturated assimilation and stomatal conductance were studied in saplings of the deciduous tree Terminalia ferdinandiana Excell. Mean daily maximum assimilation rates ranged from 11 µmol m-2 s-1 in the wet season to 8 µmol m-2 s-1 during the transition from the wet to the dry season. Saplings were without leaves from June to October inclusive (dry season). There was a log–linear relationship between stomatal conductance and pre-dawn leaf water potential (r = 0.76, n = 325), and a weak linear relationship between daily maximum assimilation and pre-dawn leaf water potential (r = 0.39, n = 184). Assimilation rates were higher in the morning than in the afternoon in April and May, but were similar throughout the day from December to March. Seasonal trends in assimilation could be attributed primarily to stomatal closure, but diurnal differences could not. High leaf temperatures may have been responsible for observed lower assimilation rates in the afternoon in April and May. Assimilation and stomatal conductance decreased when leaf temperatures rose above 38˚C and/or the leaf-to-air vapour pressure difference exceeded 4–4.5 kPa. Pre-dawn leaf water potentials decreased more quickly, and stomatal conductance was more sensitive to this decrease, in T. ferdinandiana saplings than in saplings of Eucalyptus tetrodonta F.Muell. a co-occurring evergreen tree. Specific leaf area and assimilation per unit dry weight were higher in T. ferdinandiana than in E. tetrodonta which is consistent with other studies of costs and benefits of deciduousness.
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Gould, Susan. "A survey of the birds of the Darwin Stringybark Eucalyptus tetrodonta forest: When is a survey ‘complete’?" Australian Field Ornithology 37 (2020): 155–60. http://dx.doi.org/10.20938/afo37155160.
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Bowman, D. M. J. S., and L. D. Prior. "Impact of Aboriginal landscape burning on woody vegetation in Eucalyptus tetrodonta savanna in Arnhem Land, northern Australia." Journal of Biogeography 31, no. 5 (April 14, 2004): 807–17. http://dx.doi.org/10.1111/j.1365-2699.2004.01077.x.
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Short, Terrence A., Peter M. Kopittke, David R. Mulligan, and Neal W. Menzies. "Growth of Eucalyptus species in a Brown Kandosol, and changes in soil phosphorus fractionation following fertilisation." Soil Research 45, no. 3 (2007): 190. http://dx.doi.org/10.1071/sr06147.
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As observed with many soils, much of the P in the Brown Kandosol soils of Weipa (Australia) is associated with organic matter. However, following bauxite mining, much of this organic matter is either lost due to mineralisation, or is ‘diluted’ by the mixing of the soil profile. Using a sequential P extraction, the partitioning of P following fertiliser application was examined in an ‘undisturbed’ (Surface) soil and a Mixed soil. In addition, the effect of split-P applications on the growth of 2 native Eucalyptus species was examined. Following its addition to the soil, much of the P was converted comparatively rapidly to forms with reduced availability; by the time of the first measurement (4 weeks) only approximately 10% of the added P remained as the readily available AER-P. For the Surface soil, much of this added P was initially converted to organic P (Po) (measured as hydroxide-Po), before progressively moving into the hydroxide-Pi fraction. In comparison, in the mixed soil, competition for P from microbial biomass was lower (due to a lower organic matter content) and the P was rapidly converted to the hydroxide-Pi fraction before moving to unavailable forms (residual P). Although the use of split-P applications was expected to increase plant growth, maximum growth of Eucalyptus tetrodonta and Eucalyptus leptophleba was generally achieved when all P fertiliser was applied in the first few weeks of growth. Indeed, splitting the P application beyond 16 weeks caused a significant reduction in growth.
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Eamus, D., X. Chen, G. Kelley, and L. B. Hutley. "Root biomass and root fractal analyses of an open Eucalyptus forest in a savanna of north Australia." Australian Journal of Botany 50, no. 1 (2002): 31. http://dx.doi.org/10.1071/bt01054.
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Below-ground biomass of a Eucalyptus savanna forest was estimated following trenching to depths of 2 m around 16 mature trees in a tropical savanna of north Australia. Correlations among below-ground and various components of above-ground biomass were also investigated. In addition, root morphology was investigated by fractal analyses and a determination of an index of shallow-rootedness was undertaken. Total root biomass was 38.4 t ha–1, including 1 t ha–1 of fine roots. About 77–90% of total root biomass was found in the upper 0.5 m of soil. While fine-root biomass density was approximately constant (0.1 kg m–3) in the top soil, irrespective of distance from a tree stem, coarse-root biomass showed large variation with distance from the tree stem. Significant positive correlations among total root biomass, total above-ground biomass, diameter at breast height, leaf biomass and leaf area were obtained. It is likely that total root biomass can be reasonably accurately estimated from aboveground biomass and fine-root biomass from tree leaf area. We present equations that allow the prediction of belowground biomass from above-ground measures of tree size. Root morphology of two evergreen and two deciduous species was compared by the use of three parameters. These were the fractal dimension (d), which describes root system complexity; a proportionality factor (α), which is the ratio of the cross-sectional area before and after branching; and two indices of shallow-rootedness (ISR). Roots were found to be amenable to fractal analyses. The proportionality factor was independent of root diameter (Dr) at any branching level in all tree species examined, indicating that branching patterns were similar across all root sizes. The fractal dimension (d) ranged from 1.15 to 1.36, indicating a relatively simple root structure. Mean d was significantly different between E. tetrodonta (evergreen) and T. ferdinandiana (deciduous); however, no significant differences were found among other pairs of species. Terminalia ferdinandiana had the highest ISR, while Planchonia careya (deciduous) had the lowest. In addition, differences in ISR between P. careya and the other three species were significant, but not significant among E. miniata, E. tetrodonta and T. ferdinandiana. There were clear relationships among above-ground tree stem diameter at breast height, stem base diameter, and horizontal and vertical proximal root diameter. By the use of mean values of and stem diameter, we estimated the total crosssectional area of root and root diameter-class distribution for each species studied.
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Sharp, Ben R., and David M. J. S. Bowman. "Patterns of long-term woody vegetation change in a sandstone-plateau savanna woodland, Northern Territory, Australia." Journal of Tropical Ecology 20, no. 3 (April 21, 2004): 259–70. http://dx.doi.org/10.1017/s0266467403001238.
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Aerial photographs were used to assess changes in woody vegetation cover at 122 locations within a sandstone-plateau savanna woodland in the Victoria River region, Northern Territory, Australia. Despite locally variable vegetation responses, there has been little change in total woody vegetation cover since 1948. Thirty-three locations were also surveyed on the ground. It was found that sites for which vegetation cover had changed over the 50-y period were not significantly different from stable sites in terms of floristic composition, recent fire history, demographic stability among the dominant tree species, or edaphic setting. However, two of the dominant overstorey tree species – Eucalyptus tetrodonta and Eucalyptus phoenicea – showed significantly higher mortality on sites that had experienced vegetation cover decline since 1948. We suggest that observed changes in woody vegetation cover are a consequence of natural cycles of die-back and recovery of at least these two species in response to spatially heterogenous variables such as dry-season moisture stress. Although the widespread decline of fire-sensitive Callitris intratropica populations clearly indicates a historical shift from lower- to higher-intensity burning conditions within the study area, we reject the hypothesis of a landscape-wide process such as changing fire regimes or climatic change as the driving factor behind large-scale vegetation changes detected by aerial photographic analysis.
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Eamus, Derek, G. A. Duff, and C. A. Berryman. "Photosynthetic responses to temperature, light flux-density, CO2 concentration and vapour pressure deficit in Eucalyptus tetrodonta grown under CO2 enrichment." Environmental Pollution 90, no. 1 (1995): 41–49. http://dx.doi.org/10.1016/0269-7491(94)00088-u.
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Mazerand, Cécile, and Ian Edwin Cock. "The Therapeutic Properties of Plants Used Traditionally to Treat Gastrointestinal Disorders on Groote Eylandt, Australia." Evidence-Based Complementary and Alternative Medicine 2020 (November 10, 2020): 1–17. http://dx.doi.org/10.1155/2020/2438491.
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The First Australians had well-developed healing systems. Groote Eylandt inhabitants used a variety of plant species to treat diarrhoea and other gastrointestinal illnesses. This study was undertaken to test, identify, and evaluate traditional medicines to treat these conditions against gastrointestinal bacterial, protozoal, and viral pathogens, as well as against cancer cell proliferation. Six plant species (Buchanania obovata Engl., Casuarina equisetifolia L., Eucalyptus tetrodonta F. Muell., Planchonia careya (F. Muell.) R. Knuth, Terminalia carpentariae C. T. White, and Vigna vexillata (L.) A. Rich.) were selected from a survey of a panel of elders from the Warnindhilyagwa tribe and compared with the published literature. Decoctions prepared according to traditional methods were screened for growth inhibitory activity of a panel of diarrhoea-causing bacterial pathogens by disc diffusion and liquid dilution MIC assays. Inhibitory activity against the gastrointestinal protozoal parasite Giardia duodenalis and antiproliferative activity against human colorectal (Caco2) and cervical (HeLa) cancer cell lines were evaluated using MTS-based colorimetric cell proliferation assays. Preliminary antiviral screening was accomplished using an MS2 bacteriophage plaque reduction assay. Toxicity was evaluated using Artemia franciscana nauplii mortality and HDF cell viability bioassays. All traditional medicines tested inhibited bacterial growth, often with MIC values substantially <1000 μg/mL. T. carpentariae was particularly noteworthy, with MIC values of 230–350 μg/mL against Citrobacter freundii, Salmonella newport, Shigella sonnei, Staphylococcus aureus, and Staphylococcus epidermidis. This species also had MICs 450–950 μg/mL against all other bacterial pathogens. B. obovata Engl. and E. tetrodonta were also good inhibitors of bacterial growth, albeit with substantially higher MIC values than determined for T. carpentariae. The T. carpentariae decoction was also the best inhibitor of MS2 phage replication (IC50 = 427 μg/mL) and Caco2 and HeLa proliferation (IC50 values of 885 and 85 μg/mL, respectively). None of the extracts were particularly strong inhibitors of Giardia duodenalis growth. All decoctions were nontoxic in the Artemia nauplii and HDF cell viability bioassays, indicating their suitability for therapeutic use.
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Leggate, William, Robert L. McGavin, Andrew Outhwaite, Jack Dorries, Rhianna Robinson, Chandan Kumar, Adam Faircloth, and Mark Knackstedt. "The influence of mechanical surface preparation method, adhesive type, and curing temperature on the bonding of Darwin stringybark." BioResources 16, no. 1 (November 16, 2020): 302–23. http://dx.doi.org/10.15376/biores.16.1.302-323.
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Darwin stringybark (Eucalyptus tetrodonta) is one of Northern Australia’s most important commercial forest resources. The wood exhibits desirable wood properties including high strength, natural durability, and visual appeal. The production of engineered wood products (EWPs) such as glulam from this resource represents a significant commercial opportunity for the timber industry in northern Australia. However, a major challenge to overcome is the achievement of satisfactory glue bond performance. This study evaluated the effects of different surface machining preparations, adhesive types, and curing temperatures on the bonding characteristics of Darwin stringybark. The pre-gluing surface machining method significantly influenced the timber wettability, roughness, permeability and tensile shear strength of adhesive bonds. Planing resulted in the lowest wettability, roughness, and permeability, while bonded planed samples produced the poorest tensile shear strength. Alternative surface machining methods including face milling and sanding post-planing were shown to significantly improve the timber wettability, roughness, and permeability, and also to increase the tensile shear strength of bonded samples. The resorcinol formaldehyde adhesive resulted in slightly improved tensile shear strength in most cases compared to the polyurethane adhesive. There was no significant improvement in tensile shear strength with the use of elevated temperature curing.
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Werner, Patricia A., Lynda D. Prior, and Josh Forner. "Growth and survival of termite-piped Eucalyptus tetrodonta and E. miniata in northern Australia: Implications for harvest of trees for didgeridoos." Forest Ecology and Management 256, no. 3 (July 2008): 328–34. http://dx.doi.org/10.1016/j.foreco.2008.04.027.
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Gibbs, Adele K., Frank Udovicic, Andrew N. Drinnan, and Pauline Y. Ladiges. "Phylogeny and classification of Eucalyptus subgenus Eudesmia (Myrtaceae) based on nuclear ribosomal DNA, chloroplast DNA and morphology." Australian Systematic Botany 22, no. 3 (2009): 158. http://dx.doi.org/10.1071/sb08043.
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Phylogenetic analysis of Eucalyptus subgenus Eudesmia is presented on the basis of the following three datasets: sequences of the internal transcribed spacer (ITS) and the external transcribed spacer (ETS) regions from nuclear rDNA, sequences of the psbA–trnH intergenic spacer region from chloroplast DNA, and morphological characters, including stamen bundling, operculum development, seeds and trichomes. Studies of floral development were essential for understanding the morphology of mature flowers and interpretation of synapomorphy and homoplasy. A summary phylogeny was constructed from a maximum parsimony analysis of those nodes coded as characters that had support in the molecular trees together with morphological characters. A revised infra-subgeneric classification is presented on the basis of the summary phylogeny, and compared with classifications of Hill and Johnson (1998) and Brooker (2000). Differences relate to relationships between clades and taxonomic rank (sections, series and subseries) and valid names of Brooker (2000) are conserved where possible. One main clade of 14 species (section Limbatae), many of mallee growth form, was found in all analyses; this clade is distributed in the South-West of Western Australia and adjacent Interzone and desert areas. A second main clade (section Complanatae) occurs in the northern and eastern tropical and subtropical regions of Australia, including Kimberley, Arnhem, Queensland and New South Wales. This section includes E. tetrodonta, previously treated as an isolated taxon in a monotypic section; however, this species is related to E. baileyana, E. similis, E. lirata and series Miniatae. The hypothesised phylogeny provides a framework for further analyses of biogeography and ecology, including functional traits.
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Kelley, G., A. P. O'Grady, L. B. Hutley, and D. Eamus. "A comparison of tree water use in two contiguous vegetation communities of the seasonally dry tropics of northern Australia: the importance of site water budget to tree hydraulics." Australian Journal of Botany 55, no. 7 (2007): 700. http://dx.doi.org/10.1071/bt07021.
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Tree water use in two contiguous communities (eucalypt open-forest and Melaleuca paperbark forest) was measured in tropical Australia, over a 2-year period. The aims of the study were to (1) quantify daily and seasonal patterns of water use in each community, (2) compare patterns of water use among the communities and (3) compare relationships among tree size, sapwood area and water use within the two contrasting vegetation communities. Access to deep soil water stores and the effect of run-on from the eucalypt forest resulted in a relatively high pre-dawn water potential throughout the year, particularly for Melaleuca forest. There were no differences in daily rates of water use, expressed on a sapwood area (Q s) basis, between the two eucalypt species examined (Eucalyptus miniata Cunn. Ex Schauer and E. tetrodonta F.Muell) at any time in the eucalypt forest. For both the eucalypt and Melaleuca forests, there was less seasonal variation in water use expressed on a leaf area (Q l) basis than on a Q s basis, and neither year nor season were significant factors in Q l. In the mono-specific Melaleuca forest, Q s was not significantly different between years or seasons. Water use on a Q l basis was similarly not significantly different between years or seasons in the Melaleuca forest. Leaf area index (LAI) of the eucalypt forest was about half of that of the Melaleuca forest throughout the year but sapwood area per hectare was 33% larger in the eucalypt than the Melaleuca forest, despite the basal area of the Melaeuca forest being almost double that of the eucalypt forest. There was no significant difference in stand water use (mm day–1) between eucalypt and Melaleuca forests during 1998; however, in 1999 Melaleuca stand water use was larger than that of the eucalypt forest. Because of the enhanced dry-season availability of water in the Melaleuca forest and its larger LAI, average annual water use of the Melaleuca forest was almost 60% larger than that of the eucalypt forest. Despite differences in Q l, Q s and annual water use between forests, the ratio of LAI to stand water use was similar for all seasons in both forests. The applicability of ‘universal rules’ linking tree water use and tree hydraulics and the importance of ecosystem location on site water budgets and plant adaptations are discussed.
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Myers, Bronwyn A., G. A. Duff, D. Eamus, I. R. Fordyce, A. O'Grady, and R. J. Williams. "Seasonal Variation in Water Relations of Trees of Differing Leaf Phenology in a Wet - Dry Tropical Savanna near Darwin, Northern Australia." Australian Journal of Botany 45, no. 2 (1997): 225. http://dx.doi.org/10.1071/bt96015.
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The seasonal variation in leaf xylem pressure potential at dawn (ψdawn), leaf tissue water characteristics and daily maximum leaf conductance was measured in eight woody species in a wet–dry tropical savanna near Darwin, northern Australia, between October 1992 and October 1993. The species were Eucalyptus miniata, E. tetrodonta, E. clavigera, Xanthostemon paradoxus, Erythrophleum chlorostachys, Planchonia careya, Terminalia ferdinandiana and Cochlospermum fraseri. The species represented the major leaf phenological types, evergreen, semi-deciduous and fully deciduous. The climate of the region is characterised by annual drought during the winter months, when virtually no rain falls and vapour pressure deficit (VPD) in the afternoon reaches 3 kPa for 5 consecutive months each year. Despite this drought, ψdawn remained high (–1.3 to –1.5 MPa in evergreen species and –0.5 to –1.5 MPa in deciduous species) relative to those trees that experience summer drought in temperate and arid Australia. There was a tendency for evergreen and semi-deciduous species to maintain positive turgor to lower xylem pressure potentials (mean osmotic potential at incipient plasmolysis, π0 = –2.15 MPa) than the fully deciduous species (π0 = –2.03 MPa). For all species, the daily maximum leaf conductance (gmax) was maximal in the wet and decreased during the dry season. Diurnally, (gmax occurred near midday in the wet season, but at about 0800–1000 hours during the dry season and the ‘buildup’, the transitional period between the dry and wet seasons. There was substantial decrease in (gmax (from 650–1000 mmol m-2 s-1 in March to 200 mmol m-2 s-1 in May) early in the dry season in two of the three fully deciduous species (Planchonia careya and Cochlospermum fraseri). The dominant evergreen species Eucalyptus miniata, by contrast, had high gmax (> 400 mmol m-2 s-1) throughout the dry season, suggesting it had access to groundwater. For each species, gmax declined with decreasing dawn water potential in a log-linear manner; the slope of this relationship tended to increase with increasing degree of deciduousness.
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Leggate, William, Robert L. McGavin, Andrew Outhwaite, Benoit P. Gilbert, and Shanmuganathan Gunalan. "Barriers to the Effective Adhesion of High-Density Hardwood Timbers for Glue-Laminated Beams in Australia." Forests 13, no. 7 (July 1, 2022): 1038. http://dx.doi.org/10.3390/f13071038.
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A number of international timbers of high commercial importance are extremely difficult to glue, which is significantly hindering access to global market opportunities for engineered wood products, especially for heavily demanded structural products. Some particularly problematic timbers in Australia are the dominant commercial hardwood species, including spotted gum (Corymbia spp.) and Darwin stringybark (Eucalyptus tetrodonta). These species are renowned for their very high mechanical properties, natural durability and attractive aesthetic appeal. However, they are notoriously difficult to glue, especially for sawn laminate-based engineered wood products, such as structural glue-laminated beams. Despite considerable effort and testing of diverse internationally established best-practice approaches to improve adhesion, glue-laminated beam samples of these timbers still frequently fail to meet the requirements of the relevant standard, mainly due to excessive glue line delamination. This paper discusses the key barriers to effective adhesion of these high-density timbers and particularly emphasises the necessity of achieving greater adhesive penetration. Greater adhesive penetration is required to enhance mechanical interlocking, entanglement and molecular interactions between the adhesive and the wood to achieve stronger and more durable bonds. Potential solutions to enhance adhesive penetration, as well as to improve gluability in general, are discussed in terms of their likelihood to satisfactorily prevent delamination and the potential to be applied at an industrial scale. This new fundamental understanding will assist the development of solutions, allowing industry to commercialise newly engineered wood products made from high-density timbers.
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Williams, RJ, AM Gill, and PHR Moore. "Seasonal Changes in Fire Behaviour in a Tropical Savanna in Northern Australia." International Journal of Wildland Fire 8, no. 4 (1998): 227. http://dx.doi.org/10.1071/wf9980227.
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In a landscape-scale experiment, fires were lit in replicate catchments 15-20 km2 in area, either early in the dry season (June) or late in the dry season (September) between 1990 and 1994. For each fire, Byram-intensity was determined in representative one ha areas of Eucalyptus miniata – E. tetrodonta open-forest, with a ground stratum dominated by annual grasses. Fuel weights were measured by harvest, fuel heat content was assumed to be constant, and the rate of spread was determined using electronic timers. Fuels consisted primarily of grass and leaf litter, and ranged from 1.5 to 13 t ha-1; in most years, average fuel loads were 2-4 t ha-1. Rates of spread were generally in the range of 0.2-0.8 ms-1. The mean intensity of early dry season fires (2100 kW m-1) was significantly less than that of the late dry season fires (7700 kW m-1), primarily because, in the late dry season, there was more leaf litter, fuels were drier, and fire weather was more extreme. Crown fires, a feature of forest fires of high intensity in southeastern Australia, were not observed in the Kapalga fires. Fire intensity was a very good predictor of both leaf-char height and leaf-scorch height for fires between 100 kW m-1 and 10,000 kW m-1, the range in which the majority of experimental fires fell.
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"Eucalyptus tetrodonta." CABI Compendium CABI Compendium (January 7, 2022). http://dx.doi.org/10.1079/cabicompendium.22499.
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