bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vegetation‐soil relations in the lowlands of south‐west Tasmania
Authors: BOWMAN D. M. J. S. , MACLEAN A. R. , CROWDEN R. K. 
Published: July 2006

AbstractA geographic survey of 14 south‐west Tasmanian sedgeland‐heaths revealed that soil organic matter is related to: water content: total nitrogen (N): total and exchangeable sodium (Na), calcium (Ca) and magnesium (Mg); exchangeable potassium (K) cation exchange capacity; and total exchangeable bases. However, total and available phosphorus (P), total K and Iron (Fe). pH level and percentage base saturation were found to be Independent of organic content. Most of the soil nutrient capital is contained In the A0 horizon, the depth of which was found to be positively related to the time elapsed since the last fire. There is no clear relationship between rock type and soil fertility, but there is evidence of soil‐vegetation interaction. The sedgeland‐heath species have lower concentrations of P, Ca and Mg in their foliage and are more efficient In the withdrawal of P and K upon tissue senescence than the surrounding scrub and forest species. Over a vegetation transition from sedgeland‐heath to forest on uniform geology there was a change in soil type. The forest was found to have more fertile soils and a higher concentration of nutrients in the above‐ground biomass than the adjacent sedgeland‐heath. The ecotone was burnt between 20–30 years prior to sampling, but the fire did not kill all the forest trees, and the structural differences suggest a mare rapid recovery of forest species. Soil fertility appears to be an important factor in controlling the rate of recovery and succession following a fire, especially if the nutrient‐rich organic layer is burnt.
Light interception and its relation to structural differences in three Australian rainforest canopies
Authors: LOWMAN M. D. 
Published: July 2006

AbstractRelative differences in the seasonality of light penetrating the canopies of three Australian rainforests were measured directly with a quantum meter and indirectly using hemispherical photographs. The mossy microphyll fern forest had higher incident light levels (100–200 μEinstein m−2 per s) and more sky visible (21.8%) at ground level than the simple (5–20 μEinstein m−2 per s with 11.2% skylight) and complex (5–10 μEinstein m−2 per s with 10.8% skylight) notophyll vine forests. There were no significant changes in amounts of sky visible through the canopy over time (10 months) for any canopy, despite the fact that leaf‐fall was a seasonal event. Profile diagrams were constructed at each site to illustrate the depth and stratification of the canopy, and the differences in these structural features were related to the variation in light attenuation. Ecological aspects of light interception through rainforest canopies are discussed, including tree branch growth patterns and leafing phenologies, and seedling regeneration on the forest floor.
Patterns of morphology and behaviour in a cicada guild: A neutral model analysis
Authors: MACNALLY RALPH C. , DOOLAN JANE M. 
Published: July 2006

AbstractMorphological and behavioural patterns were examined in a guild of nine species of eastern Australian cicadas. Co‐occurrence in, and structure of, 44 study plots were determined to relate morphological and behavioural patterns to habitat overlap and habitat structure. Multi‐variate analyses were employed to generate relationships between the species. Guild substructure shown by the habitat analyses cannot be predicted from the group substructure indicated by the morphology/behaviour analyses. Therefore, extant combinations appear to be random collections from the nine‐species pool insofar as morphology and behaviour are concerned. In particular, the most generalized species (in terms of habitat) are relatively extreme in morphology and behaviour, and vice versa. Despite these results, there are weak indications that at least two suites of characters exist, and that one of them is associated with each of the most extreme types of habitat. The reasons for these apparently contradictory results are discussed. There is no evidence to suggest that systematic morphological divergence has occurred in this guild.
Nutrient changes in surface soils after an intense fire in jarrah (Eucalyptus marginata Donn ex Sm.) forest
Authors: GROVE T. S. , O'CONNELL A. M. , DIMMOCK G. M. 
Published: July 2006

AbstractThe effects of an intense fire on the nutrient status of jarrah(Eucalyptus marginata Donn ex Sm.) forest soils were investigated. At seven experimental sites, representing a range of soil and vegetation types, surface soils were sampled to a maximum depth of 20 cm before, immediately after, and 1 year after the fire.Immediately after the fire, concentrations of total and extracted nutrients in surface (0–3 cm) soils increased markedly. One year later, concentrations of extracted nutrients in surface soils had returned to levels close to pre‐burn concentrations. During this period, some properties of sub‐surface (3–20 cm) soils also changed: Bray‐extractable phosphorus and electrolytic conductivity decreased, whereas ex‐tractable potassium and pH increased relative to pre‐burn concentrations. Initial increases in concentrations of extractable forms of nutrients were determined largely by the amounts of nutrients deposited in fine ash, whereas the changes after 1 year depended more on the leaching of ions and their reactions with the mineral soil.Increases in total amounts of major nutrients in surface soils arising from additions of fine ash were generally well correlated with amounts in pre‐burn litter and with amounts in the components of organic matter likely to be consumed in the fire. Significant quantities of all nutrients are redistributed from aboveground sources to the soil surface during intense fires, including nutrients which are most susceptible to losses through volatilization. This redistribution of nutrients is discussed in relation to short‐term and long‐term effects on plant growth and functioning of the jarrah ecosystem.
The composition, structure and distribution of heathland and grassland communities in the subalpine tract of the Bogong High Plains, Victoria
Authors: WILLIAMS R. J. , ASHTON D. H. 
Published: July 2006

Abstract In the subalpine tract of the Bogong High Plains (37°S, 147°E; altitude 1600–1800 m a.s.l.) the vegetation consists of a mosaic of snow gum (Eucalyptus pauciflora) woodland, heathland, grassland and wetland communities. Classification (polythetic‐agglomerative) and ordination (principal co‐ordinates analysis) of quadrat data from heathlands and grasslands on relatively well drained sites allowed the identification of four main heathland and grassland vegetation units. These units may be ranked in a structural and floristic continuum, from closed heath variously dominated by Prostanthera cuneata, Orites lancifolia and Phebalium squamulosum to closed heath dominated by P. squamulosum and Grevillea australis, open grassy heath of G. australis and Poa hiemata. and grassland of P. hiemata. The transition from Prostanthera closed heath to Poa grassland is correlated with gradients of decreasing steepness and rockiness of terrain, and increasing exposure and frost.
Bushfire incidence, fire hazard and fuel reduction burning
Authors: GILL A. M. , CHRISTIAN K. R. , MOORE P. H. R. , FORRESTER R. I. 
Published: July 2006

AbstractDaily routine 3 p.m. meteorological data for Melbourne, Victoria, were processed to provide estimates of maximum forest fire danger index (including soil‐water deficit), potential number of days for failure of fire suppression for given quantities of fuel, and potential number of days for optimal prescribed fuel reduction burning in eucalypt forests given the same quantities of fuel. Although two models for estimating soil dryness gave widely different results, the effect of these differences on the value of the McArthur forest fire danger index (FFDI) was relatively small overall. However, over the 28 years of record, the number of ‘extreme’ days given using the Mount dryness index was 50% greater than that given by the Keetch‐Byram index.The number of forest fires in Victoria (as a whole) was found to be related to 3 p.m. FFDI (for Melbourne) and to the incidence of weekends or public holidays. Potentially, bushfires near Melbourne would be ‘uncontrollable’; that is, with an intensity greater than 4000 kW m‐1 on level ground, on an average of about 100 days per year (at 3 p.m.) if ignition were to occur where litter fuel weights were about 301 ha‐1. However, if fuel weights were less than 81 ha‐1, the potential number of ‘uncontrollable’ fires would be near zero. Using equations to predict conditions ideally suited to safe fuel reduction burning at 3 p.m. the average number of appropriate days per year increased from zero at a fuel weight of near 71 ha‐1 to a maximum of 14 at 15 t ha‐1. The extent to which the models used in this study are accurate is arguable so further work is needed.
Factors influencing the maintenance of an inverted Eucalyptus coccifera tree‐line on the Mt Wellington Plateau, Tasmania
Authors: GILFEDDER L. 
Published: July 2006

AbstractThe Tasmanian snow gum, Eucalyptus coccifera Hook.f., forms low‐open woodlands on the dolerite plateau of Mt Wellington, Tasmania. The species occurs at the inverted and upper slope tree‐lines, and its spatial distribution appears to be strongly influenced by soil drainage characteristics. Both experimental work and field observations indicate that water‐logging is the principal agent determining the inverted tree‐line limits of E. coccifera on Mt Wellington. However, deficiencies of moisture also play a role in limiting the distribution of snow gums. There was no evidence to indicate that frost influences the lower tree‐line limits of the species, despite the genetic variation shown in the frost resistance of trees from various provenances. Strong ice‐bearing winds influenced the morphology of E. coccifera individuals, but was not a factor in limiting the distribution of the species.
Demography of woody plants in relation to fire: Banksia ericifolia L.f. and Petrophile pulchella (Schrad) R.Br.
Authors: BRADSTOCK R. A. , O'CONNELL M. A. 
Published: July 2006

AbstractPlants of Banksia ericifolia and Petrophile pulchella are sensitive to fire. Changes in population size under different fire regimes were estimated, based on measurements of post‐fire seedling emergence, seedling survival, survival and seed production in established plants of differing ages, survival of seeds held in serotinous cones and seed‐release in the periods between fire.Seeds were first available at 5 years in P. pulchella and 6 years in B. ericifolia. Exact replacement would be possible when burnt at these ages, if seedling establishment were very high. Low establishment would delay replacement to 13 years of age in both species. Late summer/autumn fires of high intensity favour high establishment. Such fires at 8–10 year intervals would be tolerated without any sustained decline in numbers. Fires at 10–15 year intervals could occur regardless of season or intensity with little risk of a population decline. Large increases in numbers and density would follow fires spaced at 15–30 years. Enough seeds would be available for replacement up to about 50 years in both species. Viable seed‐release in unburnt conditions was sufficient to compensate for deaths in stands over 20 years old, even with very low levels of establishment.Two variables accounted for the biggest changes in numbers and density between generations interspersed by fires; namely the age at which a stand is burned and the proportion of seeds which emerge as seedlings. A comparison with other similar species showed similarities in controls on emergence and establishment, lengths of primary juvenile periods and life spans.
Holocene vegetation, fire and environmental history of the Discovery Bay region, south‐western Victoria
Authors: HEAD LESLEY 
Published: July 2006

AbstractThe results of pollen, sedimentary and charcoal analyses of four cores and three peat profiles are presented. Casuarina woodland dominated the dryland vegetation over at least the past 6000 years, with a Melaleuca lanceolata‐composite scrub association on the dunes. There is no evidence of higher sea levels in the area in the past 6000 years, with the present freshwater backdune swamp and lake systems being maintained or expanded. After a period of regional dune building between about 6000 and 4000 years BP, dune mobilization and advance in the last 4000 years or so overrode seaward brackish and fresh swamp systems. This dune advance severed Long Swamp from the Glenelg River estuary and precipitated the development of freshwater swamp conditions there. Burning of the swamp surface, often associated with the presence of Typha, is evident in a number of peat samples and is probably primarily anthropogenic. Continuous low‐level burning occurred throughout the dryland vegetation of the region but is not associated with any long‐term or widespread vegetation change. None of the environmental changes identified require a purely climatic explanation, and all have relevance for discussions of the regional prehistory.
Volume and activity of micro‐organisms in litter from native and sown temperate pasture species
Authors: HUTCHINSON K. J. , KING K. L. 
Published: July 2006

AbstractA serial extraction method was developed to estimate microbial volume in pasture plant litter. Litter from six species was evaluated over four seasons and a five fold range in microbial volume per unit mass was established in the descending order of: Trifolium repens, Lolium perenne, Festuca arundinacea, Phalaris aquatica, Poa sieberana and Themeda australis. The ranking among litter sources was the same for both fungi (F) and bacteria (B) and the ratio F/B ranged from 4 to 10. Accompanying respiration measurements (O2) were made over a range of litter moisture and at temperatures which represented field conditions. Maximum responses of respiration to moisture were estimated for each source and season, along with the Q10 temperature effects between 5, 15 and 25°C.Potential microbial production and generation times were calculated for the six litters. Differences between litters were associated with microbial standing crops rather than turnover times. However, moisture and temperature appeared to be the major determinants of seasonal responses, for example, Q10 effects. Microbial parameters calculated for Phalaris aquatica. in the field environment, were in substantial agreement with those from Eriophorum sp. in a tundra site (Flanagan & Bunnell 1976). Residues quality, as reflected by the amount and activity of microbial colonizers, is discussed in relation to the potential of management to enhance biological mineralization of pasture residues.
Consequences of differences in body mass, wing length and leg morphology for nectar‐feeding birds
Authors: COLLINS BRIAN G. , PATON DAVID C. 
Published: July 2006

AbstractNectar‐feeding birds are prominent in many parts of the world, and vary with respect to body size. Despite the availability of considerable morphometric data, few concerted efforts have been made to assess the influence of attributes such as mass, wing length and leg morphology upon the speed, acceleration, mode and energetic cost of movement by birds between flowers when foraging for nectar. This review attempts to consolidate and interpret available data and highlight areas where further investigations appear warranted. Australian honeyeaters are generally larger, and American hummingbirds smaller, than Hawaiian honeycreepers and sunbirds of Africa or Asia. Sunbirds, honeyeaters and honeycreepers generally perch while extracting nectar from flowers. Hummingbirds usually hover, apparently because suitable perches close to flowers are lacking, and not because hovering increases the speed at which flowers can be visited. Honeyeaters move from one flower to another at speeds that are at least as great as those for hummingbirds. Most passerine nectarivores need to ingest more nectar per day than hummingbirds in order to maintain energy balance, some species devoting more than 60% of the day to foraging. The major consequence of reduced foraging activity by hummingbirds, which spend only 5–30% of the day in this manner, appears to be male emancipation from nest construction and care of offspring. Large nectarivores have a greater capacity to store surplus food and to fast than smaller birds, and so can take advantage of short‐lived peaks in nectar abundance. Nectarivores such as honeyeaters should therefore be favoured by the rapid diurnal changes in nectar availability which are characteristic of many Australian and African habitats. Body mass also determines the likely access to rich sources of nectar through size‐related interspecific dominance hierarchies. In all families, larger species tend to monopolize the most rewarding nectar supplies, forcing smaller subordinate species to use poorer, more scattered sources. Within particular species, males usually have longer wings and greater masses than females. These variations imply that the two sexes differ with regard to their foraging ecology, although few supporting data are currently available.
Interspecific competition between mice: A reciprocal field manipulation experiment
Authors: FOX BARRY J. , GULLICK GRAEME 
Published: July 2006

AbstractPrevious studies have demonstrated a species replacement sequence in disturbed forest and heathland, with the native New Holland mouse (Pseudomys novaehollandiae) replacing the introduced house mouse (Mus musculus) in the earliest part of the succession. The replacement appeared to be competitive displacement and this has been confirmed by controlled experimental removal of P. novaehollandiae from field sites, which produced significant increases in the abundance and habitat use of Mus musculus. This paper reports the results of the controlled reciprocal manipulation experiment in the field. A pulsed addition of M. musculus to three treatment plots produced significant reductions in the abundance and habitat use of P. novaehollandiae, when compared with control plots with no addition of M. musculus. This effect was observed only at high M. musculus densities, and the return to the control conditions within 3 months of the pulsed addition is consistent with asymmetric interspecific competition from competitively superior P. novaehollandiae. The importance of considering the regional abundance of M. musculus in relation to its competitive ability is stressed, as at high densities M. musculus is able to create its own ecological space contrary to its more usual competitively submissive status.
A comparison of methods for assessing defoliation, tested on eucalypt trees
Authors: LANDSBERG JILL 
Published: July 2006

AbstractLittle is known of the extent to which differences in methodology contribute to differences in reported levels of tree defoliation. In this study several common methods of assessing defoliation were compared on Eucalyptus blakelyi Maiden trees growing in a stand known to sustain a range of defoliation levels. Assessments were made of whole trees and of individual leaves collected at discrete intervals as well as of tagged samples of leaves that were monitored over a year. Despite fortnightly monitoring intervals, I was not able to identify with certainty any specific cause of loss of whole leaves other than senescence. Annual defoliation assessed on discrete samples of leaves was higher than annual defoliation assessed on monitored samples, presumably because the age of leaves in the discrete samples was sometimes underestimated. Leaf‐level defoliation assessed from visual estimates was consistently higher than digitizer measurements of leaf areas, but calibration of estimates resulted in similar values. Values derived for tree‐level defoliation from leaf‐level measurements differed widely. depending on the method of calculation. For the samples collected from trees in this study, mean percentage defoliation per leaf was not an adequate descriptor of defoliation for the samples, since the frequency distributions of defoliation per leaf were markedly non‐normal. This problem was avoided by using the samples, rather than the individual leaves, as the basic unit of expression of defoliation, with the total percentage defoliation per sample calculated from the ratio of total area of damage to total potential area, summed for all the leaves in the sample. For expanding leaves, the percentage of area damaged was not equivalent to the percentage of area missing from the expanded leaves, because of differences in the relative rates of growth of holes and leaves.
Seasonal foraging activity and microhabitat selection by echidnas (Tachyglossus aculeatus) on the New England Tablelands
Authors: SMITH A. P. , WELLHAM G. S. , GREEN S. W. 
Published: July 2006

AbstractSeasonal foraging activity and microhabitat selection by echidnas on the New England Tablelands was determined by monitoring the number and relative predominance of different types of digging activity on a 2 km × 50 m transect over a 12 month period. Digging was classified into four basic types: those into the soil surface (SOILDIGS); those at the base of logs, stumps or trees (LOGDIGS); those at the base of termite mounds; and those in the litter. SOILDIGS were most prevalent, accounting for 490 (74%) of the total 666 digging records. The number of SOILDIGS correlated with season and temperature, reaching a maximum of 11 ha−1 per month in late spring and a minimum of zero in winter. SOILDIGS were attributed to searches for ants and scarab beetle larvae. Approximately half of the SOILDIGS exposed ant nests or galleries, while the remainder were presumed to result from searches for the larvae of pasture dwelling scarab beetles, particularly Sericesthis spp. Scarab beetle larvae were absent from echidna scats collected during winter but occurred in 20% of scats collected during summer, LOGDIGS accounted for 157 digging records (24%) and were attributed to searches for ants and termites, LOGDIGS did not vary with season or climate, but the proportion of LOGDIGS that exposed ant or termite nests or galleries changed from 48% in winter to 5% in summer. The distribution and density of SOILDIGS and LOGDIGS along the transect correlated significantly with the availability of echidna shelter (or refuge) sites, in all seasons Some residual variation in digging activity was explained by the number and biomass of ants active on the soil surface, but not with any other direct or indirect measures of food availability. Seasonal changes in foraging activity by echidnas, and their apparent dependence on shelters, are interpreted in an energetic context as strategies for reducing predation and overcoming a period of increased energy demand and decreased food availability experienced during winter.