bluuebunny/crossref_metadata_2025_split huggingface dataset:
Length‐weight relationships for invertebrates from forests in south‐eastern New South Wales
Authors: GOWING G. , RECHER H. F. 
Published: July 2006

AbstractThe relationship between length and weight was calculated for nine taxa of eucalypt forest and woodland invertebrates from south‐eastern New South Wales. Length and weight were highly correlated. For the majority of taxa the relationship was best described by a power model. There were no significant differences between the length‐weight regressions of Australian and North American taxa. This strengthens the value of generalized regressions for estimates of biomass from invertebrate length data in ecological studies.
The influence of insects on nutrient cycling in eucalypt forests: A beneficial role?
Authors: LAMB DAVID 
Published: July 2006

AbstractInsect herbivory is common in many Australian eucalypt forests and, some have suggested, may be greater than in comparable forests overseas. It has been hypothesized by several authors that herbivores max nutritionally advantage either individual plants or plant communities by hastening the biogeochemical cycling of nutrients. This coevolutionary development, it is argued, would be a particular advantage in poor soils. These suggestions conflict, however, with evidence that eucalypts commonly conserve nutrients by nutrient withdrawal prior to leaf abscission and recycling a considerable proportion of nutrients through an internal biochemical cycle.The various hypotheses that have been proposed are reviewed. Although there are some situations both at the individual and community level where herbivory may confer nutritional advantages it appears unlikely that high levels of herbivory in eucalypts are generally nutritionally beneficial to the plants being grazed.
Immediate effects of Ore on ants in the semi‐arid mallee region of north‐western Victoria
Authors: ANDERSEN ALAN N. , YEN ALAN L. 
Published: July 2006

AbstractThe immediate effects of a high intensity wildfire on the ant communities of a heath and a mallee site in semi‐arid north‐western Victoria are reported. Following fire the number of species trapped on the ground doubled (to ca. 80 each site), total ant abundance decreased by half (due to the demise of previously dominant species), surface activity of reproductive castes increased, and dramatic changes in species relative abundance (including shifts toward greater equitability) occurred. These changes are interpreted in terms of fire‐induced simplification of the habitat and release from competition with dominant species. The results appear to illustrate the importance of interspecific competition in structuring foraging activity in mallee ant communities. Observations are also reported on seed‐harvesting by ants, including changes in harvester ant abundance, germination from within‐nest seed storage, and the first record of Heteroponera removing seeds.
Further discussion of Phyllocladus and its pollen in Victoria during the Holocene
Authors: HEAD LESLEY 
Published: July 2006

Abstract Phyllocladus pollen was not identified in mid‐late Holocene sediments in the Otway Ranges but has been found, in western Victoria, in a surface sample and in lake sediments probably younger than 1100 BP. These results refute the view of Churchill and Dodson (1980) that Phyllocladus was present in western Victoria (probably in the Otway Ranges) through the Holocene until dry conditions caused its extinction about 1100 BP. It is concluded that the Phyllocladus pollen in western Victorian Holocene deposits is derived from sources in Tasmania and/or New Zealand.
Fecundity and fertility in Latrodectus hasselti (Araneae: Theridiidae)
Authors: DOWNES MICHAEL F. 
Published: July 2006

AbstractA total of 216 egg sacs of Latrodectus hasselti Thorell was examined to determine the proportion of infertile or otherwise inviable eggs. This proportion varied greatly between egg sacs but there was no consistent trend towards an increase or decrease in fecundity or fertility in sequences of egg sacs produced by given female spiders. It is suggested that the production of inviable eggs, by providing an early food source, may enable spiderlings to escape from unfavourable areas.
Rainfall in the wet‐dry tropics: Extreme events at Darwin and similarities between years during the period 1870–1983 inclusive
Authors: TAYLOR JOHN A. , TULLOCH DON 
Published: July 2006

AbstractThis paper supplements the existing climatic analyses for Darwin and the surrounding region, by providing a classification of years in terms of amount and distribution of rainfall, and highlighting the extreme, episodic rainfall events that have occurred in the period 1870 to 1983 inclusive. Approximately 77% of years have had significant departures from the two most frequent rainfall patterns and these are described. Much of the variation between years or groups of years lies in the dry and dry‐wet transition periods. While the reliability of rainfall in the wet‐dry tropics has been emphasized, rainfall variability over both the dry and wet seasons would seem to be an equally important characteristic, at least for the biota. In an environment such as the wet‐dry tropics, where moisture is the primary limiting factor, rainfall variability has important implications for the design and interpretation of faunal and floristic surveys, monitoring programs and field experiments.
Variation in serotiny of three Banksia species along a climatic gradient
Authors: COWLING RICHARD M. , LAMONT BYRON B. 
Published: July 2006

AbstractThe degree of serotiny (i.e. the proportion of follicles remaining closed in each year's crop of cones since the last fire) was measured in Bank‐sia attenuata, B. menziesii and B. prionotes at five sites along a climatic gradient extending 500 km north of Perth, Western Australia. The decrease in annual rainfall and increase in average temperature along the gradient paralleled a decrease in plant height and an increase in the degree of serotiny of all species. Extreme serotiny was recorded in the scrub‐heath at the xeric end of the gradient whereas two species were essentially non‐serotinous in the low woodland at the most mesic site.It is concluded that degree of serotiny is related to the fire characteristics of the site which depend on plant height. In xeric scrub‐heath, the entire canopies of the Banksia spp. are consumed by fire which promotes massive release of seed. This facilitates recruitment in an otherwise unpredictable and unreliable seedbed. In mesic woodland, where cones rarely come into contact With flames, seeds are released spontaneously and site conditions are more conducive to recruitment in the inter‐fire period.
Age, reproduction and biomass allocation in Rhopalostylis sapida(Nikau Palm)
Authors: ENRIGHT N. J. 
Published: July 2006

AbstractEstimates of age, seed production and the pattern of biomass allocation are presented for New Zealand's only native palm species Rhopalostylis sapida. The age at which palms show above‐ground stem development is uncertain, but appears to be in the vicinity of 40–50 years. Palms showing above‐ground stems shed two fronds per year, on average. By counting the number of frond scars an approximate age can be determined.Seed production increases continuously with size (and age) for palms which exceed a maturity threshold determined by stem height. Although the percentage of total plant biomass represented by reproductive structures is low, seeds may account for over 50% of nikau palm net production in a year.
Relationship between nectar production and seasonal patterns of density and nesting of resident honeyeaters in heathland near Sydney
Authors: PYKE GRAHAM H. , RECHER HARRY F. 
Published: July 2006

AbstractSome individual honeyeaters were repeatedly seen near the same location over at least a 2 day period and were considered resident in the present study. Such resident honeyeaters (mostly New Holland and White‐cheeked Honeyeaters) were present on the heathland study areas from about February until about October. Production of nectar energy is negligible prior to April and low after October. It is hypothesized that the density of residents is determined by their ability to obtain energy in nearby habitats while establishing nesting sites in the heathland in February and March. Nesting tended to occur between April and July when there was sufficient production of nectar‐energy.
Population dynamics of the shrub Acacia suaveolens (Sm.) Willd.: Dispersal and the dynamics of the soil seed‐bank
Authors: AULD TONY D. 
Published: July 2006

AbstractGenet survival in seeds of Acacia suaveolens was examined through both dispersal and dormancy in the soil in populations near Sydney.Following initial passive seed‐fall, the majority of seeds lie within a 1 m radius of the stem of the parent. Further dispersal is predominately mediated by ants. A. suaveolens seeds possess an elaiosome which attracts ants. When elaiosomes are removed, the potential for further dispersal of seeds is greatly reduced. Three species of ant disperse seeds of A. suaveolens and the fate of seeds following ant dispersal was observed to depend on the particular species of ant involved. Ants of both Iridomyrmex sp. and Pheidole sp. B are too small to drag seeds and, instead, ants of these species usually remove the elaiosome in situ, with little dispersal of the‐seed resulting. Ants of Pheidole sp. A are larger and disperse seeds further, frequently taking them into their nests where the elaisosome is removed. Seeds are retained inside the nests and incorporated into the floors and walls of passageways and chambers. Several supposed ‘advantages’ of myrmecochory were examined but none were verified. Instead, two distinct ‘disadvantages’ were identified. These were: burial of seeds by ants of Pheidole sp. A into ‘unsafe sites’; and too deep a burial of seeds in nests for seeds to receive a stimulus to germinate during fires, and for seedlings to emerge successfully. Outside nests of Pheidole sp. A. seeds are concentrated in the top 5 cm of the soil, whilst within nests of these ants, seeds are found up to 15 cm deep.The dynamics of various components of the soil seed‐bank were examined using seeds buried in nylon mesh containers. The seed‐bank is persistent without annual recruitment to seedlings, enabling a population to persist as seeds after all above‐ground plants have perished.
Movement of the Southern Australian abalone Haliotis laevigata in relation to crevice abundance
Authors: SHEPHERD S. A. 
Published: July 2006

AbstractThe long‐term movement of the abalone Haliotis laevigata was measured at three sites in Waterloo Bay, South Australia, characterized by differing amounts of available crevice space. Movement was negligible at a site where crevices were abundant, but extensive at a site without crevice space. At a site of limited available crevice space, the amount of movement increased as available crevice space decreased. In addition, the extent of movement was size dependent and movement was oriented in the direction of the approaching swell.Current experimental designs for measuring natural mortality of abalone depend heavily on assumptions about their movement. An understanding of this behaviour is thus a prerequisite for designing experiments to measure the mortality rates of abalone or other sedentary animals.The natural mortality rate at one site was estimated to be 0.59 (s.e.m. = 0.02, i.e. survival = 56% per year) and the disappearance rate (natural mortality and emigration) was independent of sex.
Influence of grazing management on vegetation, soil structure and nutrient distribution and the infiltration of applied rainfall in a semi‐arid chenopod shrubland
Authors: GRAETZ R. D. , TONGWAY D. J. 
Published: July 2006

AbstractThe experiment utilized a fenceline contrast in vegetation and soil condition that was clearly visible on Landsat imagery. Measurements of vegetation cover, soil structure and chemistry, and infiltration were made. The greatest vegetation change was at the soil surface where the loss of litter and lichen crust cover under heavy grazing accompanied the loss of perennial shrubs. Although grazing caused changes in soil structure and chemistry to less than 10 cm in depth, these changes are quite significant for plant growth. Consistent differences in the infiltration of applied rainfall at two intensities were measured between the grazed and ungrazed sites. At both intensities of application the absence of a lichen crust increased infiltration three‐fold on the heavily grazed site compared with the ungrazed site. The implications of these observations on the long‐term functioning of this landscape are discussed.
The fate of rainfall in a mallee and heath vegetated catchment in southern Western Australia
Authors: NULSEN R.A. , BLIGH K.J. , BAXTER I.N. , SOLIN E.J. , IMRIE D.H. 
Published: July 2006

AbstractMallee, a shrub‐eucalypt association, once covered large areas of the cereal growing land in Western Australia. The hydrologic consequences of land development have been more than a doubling of water yield and increased deep drainage beyond the plant‐root zone. The latter has led to large areas of soil salinization.The uncleared catchment studied was covered with mallee vegetation (65%) and a heath association (35%). Over 12 years of measurement, runoff from the catchment has averaged 0.025 mm per annum with a mean annual rainfall of 376 mm. Half of the runoff resulted from two major events totalling 0.15 mm. Since there was no evidence of groundwater accession in the catchment, the rainfall was balanced by evapotranspiration. Despite virtually no runoff from the whole catchment, considerable internal redistribution of surface water occurred, with localized overland flow in some areas as high as 7.7 mm from 30.9 mm of rainfall in one day.Rainfall penetrated rapidly under the mallee vegetation and the rate of penetration observed could not be achieved solely through the soil even if there was saturated flow.A typical stand of native mallee trees (Eucalyptus pileata and E. eremophila) in the catchment effectively redistributed 8% of the annual rain falling on the stand with 3% lost as interception and 5% going to stemflow. However, on an individual tree basis some 15% of the rain falling on the canopy was lost as intercepted water and 25% ran down the stem. The stemflow caused saturated conditions around the bole of the mallee and dye tracing showed that the water penetrated the soil via the annular pathways of the soil‐root interface.Roots of mallee trees were found at 28 m depth and it is postulated that the mallees are adapted to the semi‐arid environment by virtue of their ability to store water deep in the soil profile for use during the dry summer months.
Development of a new piosphere in arid chenopod shrubland grazed by sheep. 2. Changes to the vegetation
Authors: ANDREW MARTIN H. , LANGE ROBERT T. 
Published: July 2006

AbstractThe initial development of a piosphere created by stocking a new watering trough with ca. 200 sheep at a near‐pristine site in arid chenopod shrubland near Whyalla, South Australia, was studied. The following variables were monitored for up to 8 years using fenced plots as controls:shrub mortality; forage biomass and defoliation of the dominant shrubs and short‐lived grasses; linear dimensions of Rhagodia ulicina; the density of short‐lived species; and the invasion of exotics. Patterns in these variables were looked for which reflected the attenuation of stocking pressure with distance from water; that is, ‘piosphere patterns’. Piosphere patterns were detected for many variables. Those with values increasing towards the trough were mortality of the main forage shrub Atriplex vesicaria. the density of three short‐lived taxa, viz. the bassias (Sclerolaena obliquicuspis, S. patenticuspis. Maireana sclerolaenoides), Tetragonia tetragonoides, and annual Zygophyllum spp. (Z. crenatum. Z. ovatum), and growth of short‐lived grass species when sheep stocking pressure was low. Variables with values decreasing towards the trough were grass biomass, percentage of A. vesicaria individuals in flower, the percentage foliation of A. vesicaria and of the forage shrub Maireana sedifolia, and shrub forage biomass of A. vesicaria and M. sedifolia.The rate at which these patterns were registered varied. After only 3 months, a piosphere pattern was evident for grass biomass. Marrubium vulgare, an introduced weed, invaded the trough site within the first 6 months. Almost no A. vesicaria shrubs had died after 2 years, but after 8 years there was a marked piosphere pattern in their mortality. The piosphere patterns in forage biomass and defoliation of A. vesicaria and M. sedifolia became more pronounced with time.Some variables did not exhibit a piosphere pattern, such as the dimensions of the shrub R. ulicina and the densities of successive cohorts of the forb Erodium spp., even though there was an overall effect of grazing in reducing their values. There was no mortality of two dominant shrubs, M. sedifolia and R. ulicina, during the first 8 years.
Causes of nesting losses in the cattle egret Ardeola ibis in eastern Australia with special reference to the pathogenicity of the tick Argas (Persicargas) robertsi to nestlings
Authors: McKILLIGAN NEIL 
Published: July 2006

Abstract In a 3 year study of the cattle egret at a heronry of 3500 nests in south‐east Queensland, 34% of eggs in 711 nests observed failed to survive to become fledglings (11 day old chicks). Fledgling mortality seemed much lower. The main sources of mortality were crow predation on eggs, failure of the incubated egg to develop fully, starvation of nestlings and tick infestation of nestlings. These were of about equal importance overall but their individual magnitudes varied considerably among the three seasons. The pattern of infestation of the cattle egret chick with the tick Argas (Persicargas) robertsi and the effect of this on chick health are described. An account is given of the other sources of morbidity also. The heronry appeared to be producing a net surplus of young despite these losses.
Gregarious flowering in a lowland tropical rainforest: A possible response to disturbance by Cyclone Winifred
Authors: HOPKINS MIKE S. , GRAHAM ANDREW W. 
Published: July 2006

AbstractObservations in tropical lowland rainforests damaged by Cyclone Winifred on 1 February 1986 suggest that the disturbance has been followed by an unusual burst of flowering. Fifty‐four species of concurrently flowering shrubs and trees were recorded in early March along a 4 km road transect in a cyclone‐damaged forest. Approximately 80% of the smaller tree and shrub species observed were flowering. Twelve species which had flowered and fruited prior to the cyclone flowered again. Some species which normally flower following periods of partial or complete deciduousness in the drier months of the year flowered after being defoliated by the cyclone. Widespread defoliation of the rainforests, together with the hot, dry weather which followed the cyclone, exposed the understorey layers to abrupt increases in temperature, insolation, and water stress. It is postulated that these environmental changes may have effected the synchronization of flowering of a larger number of species than would normally occur. It is suggested that longterm changes in the species composition of the damaged forests as a result of coincidences of seed availability and regenerative space may occur.
Litter decomposition, soil respiration and soil chemical and biochemical properties at three contrasting sites in karri (Eucalyptus diversicolorF. Muell.) forests of south‐western Australia
Authors: O'CONNELL A. M. 
Published: July 2006

AbstractLitter decomposition, soil respiration and soil chemical and biochemical properties were examined at three contrasting sites in karri(Eucalyptus diversicolorF. Muell.) forest of south‐western Australia. The study sites were: a recently clearfelled area (site CF2) which had been subjected to a slash regeneration burn following clearing; a pole‐stand regrowth forest about 40 years old which had been regularly burnt by cool, prescribed fires (site RB40); and a pole‐stand regrowth forest about 40 years old which had remained unburnt for many years (site UB40).Leaf litter of uniform composition lost 40–54% of its original dry weight after decomposing for 82 weeks on the forest floor. A composite exponential model, with separate decay functions for labile and more resistant litter components, described rate of weight loss better than a simple exponential decay model. Labile components of litter were released at similar rates at the three sites. Decomposition of resistant litter components was slower (half‐life = 271 weeks) at the recently clearfelled site than at the two pole‐stand sites (half‐lives = 119 and 149 weeks). The order in which nutrients were released from decomposing litter, Na > Cl > K > Mg > S > Ca > N > P, was similar at each site. The rate of release of the more mobile elements Na, Cl, K, Mg and S, was also similar at each site. Changes in the amounts of Ca, N and P in decomposing litter differed between the three sites and the differences were related to the amounts of these nutrients in surface soil at each site.Annual soil respiration decreased in the order site CF2 = site UB40 > site RB40. Seasonal variation in respired CO2was partly explained by variation in soil moisture and temperature. Soil carbohydrase activity at the recently clearfelled site was significantly lower than at the two well vegetated pole‐stand sites. The differences between sites in enzyme activities were related to differences in the amounts of organic C in surface soils of the three sites.The amount of organic C in surface soil (0–15 cm) was 25–36% lower at the recently clearfelled site than at the two well vegetated pole‐Stand sites. Site disturbance during clearing, and combustion of soil organic matter by the subsequent slash regeneration burn, probably account for part of this difference. However, reduced inputs of organic matter in litterfall, slower rates of surface litter breakdown and increased rates of microbial mineralization of soil organic matter on recently clearfelled areas may also contribute substantially to depletion of soil organic C.
Subtidal macroalgal communities in the D'Entrecasteaux Channel, Tasmania
Authors: SANDERSON J.C. , THOMAS D. P. 
Published: July 2006

AbstractCommunity descriptions and distributions of the dominant subtidal macroalgae were recorded for the D'Entrecasteaux Channel, Tasmania. These were related to the major environmental parameters of light, water movement, substrate and depth. Six communities were recognized subjectively: (1) Durvillaea, (2) Phyllospora, (3) Macrocystis, (4) Ecklonia, (5) Fucoid and (6) Seagrass‐Cauterpa. These divisions were supported by cluster analysis of data from Tinderbox, a site at the northern end of the Channel.Detrended correspondence analysis of community data suggested that light was the principal factor (Axis 1), followed by water movement, in determining species distributions at Tinderbox.The algal communities determined are consistent with the generalized scheme proposed by Edgar (1984) for this area and are indicative of cold temperate waters and the Maugean subprovince.