bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impact of water buffalo on the monsoon forest ecosystem in Kakadu National Park
Authors: BRAITHWAITE R. W. , DUDZINSKI M. L. , RIDPATH M. G. , PARKER B. S. 
Published: July 2006

AbstractThe intensity of use of forested country in the Kakadu National Park area by feral Asiatic water buffalo can be largely predicted from the area of river floodplain in the vicinity of the site, and tree canopy cover on the site. Thus some areas of monsoon forest appear to have sustained intensive use by buffalo for over a century whereas other areas have probably been little used.With sites exhibiting little buffalo use, mean DBH of trees increased with foliage height diversity (FHD). However, the sites more intensively used by buffalo had a lower canopy and did not exhibit any increase in mean DBH with a pronounced increase in FHD. Other vegetational relationships displayed by the two groups of sites are discussed. Comparison of the monsoon forest sites suggests that compaction of soil by buffalo has caused the death of large trees due to poor recharge of groundwater.The two groups of monsoon forest sites exhibited a wide variety of faunal relationships with FHD. Some species appear to be favoured while others are disadvantaged to various degrees by the habitat changes caused by the buffalo. The most intensively used site appears to have exceeded a threshold in that a number of faunal trends were reversed on that site.The impact of buffalo on some monsoon forest sites is much more fundamental than anticipated. But other sites which appear to be naturally protected by their location have experienced much less change due to buffalo.
Is insect defoliation in eucalypt forests greater than that in other temperate forests?
Authors: OHMART C. P. 
Published: July 2006

AbstractClaims have been made in the past that insect defoliation in eucalypt forests of Australia is both chronically high and greater than defoliation levels in northern temperate forests. Recent published data, however, indicate that some eucalypt forests may sustain low level defoliation. Careful reexamination of the literature on defoliation in eucalypt forests indicates that there are not enough data available to quantify defoliation on an Australian‐wide basis. Therefore it cannot be claimed that insect defoliation in eucalypt forests is greater than that in other temperate forests. There are also insufficient data to claim that insects are a major factor responsible for the growth differential between indigenous and overseas plantation‐grown eucalypts. The ecological impact of herbivorous insects in eucalypt and northern temperate forests is also discussed.
Mortality of lignotuberous seedlings of Eucalyptus species after an intense fire in montane forest
Authors: NOBLE I. R. 
Published: July 2006

AbstractThe survival of lignotuberous seedlings of Eucalyptus pauciflora, E. dalrympleana and E. dives following an intense experimental fire was monitored in montane forest in the Brindabella Ranges, Australian Capital Territory. Percentage survival was the same for each species (60%), but it was shown that an individual was more likely to survive if it was large and growing vigorously before the fire. Survival was also enhanced if the individual was growing in a patch of low litter load and if it experienced a locally low fire intensity. Lignotuberous seedlings of E. dalrympleana, a species of the subgenus Symphyomyrtus, recovered more quickly than the other two species which are of the subgenus Monocalyptus. This result parallels conclusions concerning different initial growth rates between seedlings of the subgenera.
Temporal and spatial variability in insect grazing of the canopies of five Australian rainforest tree species
Authors: LOWMAN M. D. 
Published: July 2006

AbstractHerbivory was measured monthly for 2 years on leaves of permanently marked replicate branches in the canopies of five Australian rainforest tree species. Variability in insect grazing activities was evident with respect to several factors:

leafage — young leaves were preferred over older leaf tissue:
height — leaves closer to ground level were more heavily grazed:
light — shade leaves were preferred to sun leaves:
time — grazing was intense during spring and summer months, and almost negligible during autumn and winter, but was cumulatively similar between the 2 years:
space — grazing was extremely variable on small spatial scales such as between individual leaves and branches, but similar where hundreds of leaves were pooled on larger scales between individual canopies and among geographically different sites:
tree abundance — grazing was heavier at sites where a tree species was common than where it was rare:
host tree species.

Long term observations resulted in higher but more accurate estimates of herbivory since it was possible to quantify losses of leaves totally eaten, an event not accounted for infield methods of discrete sampling whereby leaves are merely harvested and measured for area missing. Variability in herbivory is discussed in terms of plant‐insect phenologies, plant defences, successional status of tree species, and insect behaviour.
Seasonal variation and the effects of drought on the abundance of arthropods in savanna woodland on the Northern Tablelands of New South Wales
Authors: BELL H. L. 
Published: July 2006

AbstractMonthly samples of arthropods were collected for 3 years in savanna woodland at Wollomombi, New South Wales, from the foliage of eucalypts, bipinnate acacias, Olearia viscidula Jacksonia scoparia, Exocarpos cupressiformis and Cassinia spp., and from the ground‐layer. The second and third years of the study coincided with the worst drought recorded for the area. Biomass of arthropods matched primary productivity and decreased greatly during the drought. In the first year there was a pronounced summer peak and winter low. Some species of plants showed peaks that did not conform to the overall pattern. Most arthropod groups were greatly reduced in number during the drought and some groups virtually disappeared, although coleopterans were not significantly affected. Arthropods were less severely reduced in shrubs than they were in the tree‐layer of eucalypts. Arthropods were on average smaller during winter.
Photosynthetic and growth responses to different light regimes of the major canopy species of Tasmanian cool temperate rainforest
Authors: READ J. 
Published: July 2006

AbstractSeedlings of the cool temperate rainforest tree species, Nothofagus cunninghamii, Atherosperma moschatum, Eucryphia lucida, Phyllocladus aspleniifolius, Lagarostrobos franklinii and Athrotaxis selaginoides, were grown in various light regimes and their instantaneous lightdependence curves and relative growth rates were measured. A. moschatum had the highest relative growth rate of all species in heavy shade, and its light‐dependence curves were also characteristic of a relatively shade‐tolerant species. A. selaginoides and L. franklinii seedlings raised in heavy shade had low instantaneous light compensation points but their growth rates were not distinct from that of N. cunninghamii. The maximum relative growth rate of the gymnosperms was low due to a low specific leaf area and leaf area ratio, although the maximum rates of photosynthesis on a leaf area basis were similar to N. cunninghamii and E. lucida. The low leaf area ratio and specific leaf area affected both the relative growth rate and the growth light compensation point. Although in the heaviest shade treatment there was no difference in growth rate between N. cunninghamii, E. lucida, L. franklinii and A. selaginoides, in moderate shade treatments N. cunninghamii had a higher relative growth rate than the gymnosperms and a higher maximum rate of photosynthesis on a leaf dry weight basis than all species when raised in semi‐shaded natural light conditions. These species commonly occur in mixture in Tasmanian cool temperate rainforest and these results are discussed in terms of forest dynamics.
Rates of seed removal by ants at heath and woodland sites in southeastern Australia
Authors: ANDERSEN ALAN N. , ASHTON DAVID H. 
Published: July 2006

AbstractAnts often appear to be important post‐dispersal seed predators, particularly in Australia where they are exceptionally abundant and apparently can remove large quantities of seeds from the ground. Rates of seed removal by ants usually are measured by recording removal from artificial seed baits, but the reliability of this approach has not been tested, nor have there been many attempts to integrate the results with the activity of seed‐eating ants. This paper describes the rates of seed removal, estimated using a baiting technique that is tested for its reliability, by the seed‐eating ants in adjacent heath and woodland sites at Wilson's Promontory, Victoria. Ants removed up to 100% of seeds, but rates varied according to seed species, size of seed clumps, season, time of exposure, and other aspects of the baiting technique. Methodological guidelines are provided to make baiting conditions approximately those likely to occur in nature.Seed‐eating ants, particularly species ofRhytidoponera, Chelaner and Pheidole, were by far the most important post‐dispersal seed predators, and patterns of seed removal were directly related to their composition, abundance and foraging behaviour. Lygaeid bugs were also observed eating seeds, but there was no evidence of seed predation by rodents or birds.The results suggest that seed predation by ants can substantially deplete seed reserves: however, its actual effect on seedling recruitment is likely to depend on many factors including seed size, crop size, weather, timing and location of seed fall, availability of alternative food sources, patterns of seedling mortality, and fire, none of which have been adequately investigated.
Foraging patterns of breeding birds in eucalypt forest and woodland of southeastern Australia
Authors: RECHER H. F. , HOLMES R. T. , SCHULZ M. , SHIELDS J. , KAVANAGH R. 
Published: July 2006

AbstractThe foraging ecology of eucalypt forest and woodland birds was studied on three 10 ha plots in southeastern Australia. Quantitative data were obtained for 41 species of which 31 were insectivorous, eight were nectar‐feeders, and two were parrots that fed primarily on eucalypt seeds. Birds‐of‐prey, large omnivores and frugivores were uncommon. Insectivorous birds differed in foraging behaviour, the substrates on which they found prey, and foraging height. Nectar‐ feeders exploited a variety of carbohydrates including nectar, honeydew, lerp, manna and sap. Nectarivorous birds were separated by foraging behaviour, substrate, height and by the extent to which they used the different types of carbohydrates. Carbohydrates were also an important food resource for some insectivores. By understanding how birds exploit food resources within forest and woodland environments, the features of the environment which need to be conserved or manipulated to manage forest avifaunas can be identified. For example, in addition to the substrates such as foliage and bark, usually associated with the foraging of forest birds, carbohydrates and loose bark were identified as important resources for birds in eucalypt forests and woodlands. The broad importance of these two resources to the avifauna had not been previously appreciated, yet both may be sensitive to environmental changes associated with logging and other forest management practices which alter the composition or age‐class structure of forests.
Collembolan associations in natural versus improved pastures of the New England Tableland, NSW: Distribution of native and introduced species
Authors: KING KATHLEEN L. , GREENSLADE PENELOPE , HUTCHINSON K. J. 
Published: July 2006

AbstractNative Australian species of Collembola dominated natural pasture in numbers of species present and in abundance, while introduced Collembola dominated fertilized pasture sown to exotic species. Those collembolan species which were restricted to one pasture type only were mainly epigeal and hemiedaphic species of the herbage and litter. Increased grazing by sheep decreased species richness and increased uniformity of Collembola in both pasture types. The abundance of introduced Collembola was positively associated with phosphorus content of litter.
Recovery of some surface soil properties of ecological interest after sheep grazing in a semi‐arid woodland
Authors: BRAUNACK M. V. , WALKER J. 
Published: July 2006

AbstractSolodic soils within a semi‐arid poplar box (Eucalyptus populnea) woodland at Wycanna, in southern Queensland, have been subjected to impacts from sheep and cattle grazing for at least 100 years. The micromorphology of the surface of two soils, a gradational texture profile (Gn 3.13, Paleustalf) and a duplex profile (Db 1.23, Paleustalf) showed that compaction had occurred. Recovery of the soil surfaces following removal of animal grazing was measured in terms of porosity, presence of illuvial layers, surface soil strength, some chemical properties and water infiltration rates. The grazing impact was greatest on the Gn 3.13 soil and visual signs of the grazing impact were still evident 16 years following sheep removal. Reduced soil organic matter and increased surface soil hardness as a result of grazing, rather than surface crusting or changes in water infiltration rates are suggested as the mechanisms controlling the observed increases in woody plant populations in these semi‐arid woodlands.
Niche compression: Two tests of an hypothesis using narrowly sympatric predator species
Authors: DICKMAN C. R. 
Published: July 2006

AbstractThe compression hypothesis predicts that when two species occur together in narrow sympatry, individuals in the overlap zone will use a smaller range of habitats and a larger or unchanged range of prey than individuals in allopatry. This report attempts to validate the assumptions underlying this hypothesis, and describes two tests of the predicted resource shifts using narrowly sympatric species of predatory marsupials (Antechinus spp.). In the first test, using A. stuartii and A. flavipes, there was little correspondence between observed and predicted changes in diet and habitat use (as measured by indices of niche breadth) for populations of either species. One index of niche breadth (Levins' B) revealed no trends in resource use, but a proportional similarity index relating resource use to resource abundance consistently indicated that the niche breadths of each species were greater in allopatry than in narrow sympatry. In the second test, using A. stuartii where it occurred alone and in narrow sympatry with A. swainsonii, there was again little correspondence between observed and predicted changes in resource use for seasonal or overall data. Differences in magnitudes of niche breadths between allopatric and narrowly sympatric A. stuartii were smaller in this test than in the first.While these findings provided no support for the compression hypothesis, they suggested three situations in which the predictions of the hypothesis may generally not apply. These are:

when the predators are active, dietary generalists (diet cannot expand in sympatry);
when one species is a markedly superior competitor to the other (the dominant species suffers little or no niche compression in sympatry); and
when the species compete by interference rather than exploitation (one species is evicted from sympatry or both show compression in habitat use and diet).
Herbage response to tree thinning in a Eucalyptus crebra woodland
Authors: WALKER J. , ROBERTSON J. A. , PENRIDGE L. K. , SHARPE P. J. H. 
Published: July 2006

AbstractThe effects of a range of tree densities on native herbage (mainly Aristida ramosa, Bothriochloa decipiens and Themeda australis biomass in a Eucalyptus crebra woodland near Kingaroy, Queensland, were investigated between March 1977 and July 1981. Rainfall in this area averages 750 mm year−1. Initial tree density was 640 trees ha−1 and this was manipulated using arboricide chemicals to leave plots containing 640, 320, 160, 80 and nil live trees ha−1. Fires were excluded from the whole area, and half the plots were grazed by cattle. The largest increase in herbage biomass was recorded in the ‘all trees killed’ treatment (nil trees ha−1), closely followed by the ‘scattered tree’ treatment (80 trees ha−1). The relationship between tree density and herbage biomass was linear. Recruitment of grass and forb plants, as reflected by changes in density, varied according to treatment. Increased grass recruitment was correlated with cattle grazing, whilst forb recruitment was influenced mainly by tree density.
Surface soil chemical and physical patterns in a brigalow–Dawson gum forest, central Queensland
Authors: DOWLING A.J. , WEBB A. A. , SCANLAN J. C. 
Published: July 2006

AbstractBrigalow (Acacia harpophylla)–Dawson gum (Eucalyptus cambageana) open forests are predominantly supported by solodic soils in central Queensland. This report describes relations between some physical, chemical and morphological properties of surface soils (0–0.10 m) within a virgin brigalow–Dawson gum forest. Soil property gradients were found to radiate horizontally from tree‐dominated to non‐vegetated areas, indicative of a vegetation‐induction process. These reflect the importance of litterfall organic matter in determining soil fertility and soil physical conditions at this site.The decomposition of litterfall is probably responsible for significant increases in soil organic carbon (C), total nitrogen (N) and total sulphur (S) concentrations with increasing vegetation canopy cover. The composition of soil organic matter appears constant across the study area, as similar soil C:N:S ratios were recorded across all vegetation canopy classes. Soil salinity, total phosphorus, mineral nitrogen, cation exchange capacity, exchangeable calcium and exchangeable potassium levels also increased with increasing vegetation canopy cover.Surface soil physical properties were also related to vegetation canopy cover. Bulk density and the < 20 μm dispersion ratio decreased while soil micro‐relief and A hor̀izon depth increased with increasing vegetation canopy cover. Organic C, through inverse relations with bulk density and the < 20 μm dispersion ratio, appears to enhance soil porosity and aggregate stability, indicating the role of organic matter in the stabilization of larger virgin soil aggregates.The close association between virgin forest and surface soil fertility is seen to have implications for changes in land‐use, with a decline in nutrient availability, soil aggregate stability and productivity following forest clearing.
Impact of flower and seed predators on seed‐set in two Banksia shrubs
Authors: ZAMMIT CHARLES , HOOD CHRISTOPHER W. 
Published: July 2006

AbstractA non‐systemic Insecticide was used to exclude flower and seed predators from Banksia ericifolia and B. oblongifolia Inflorescenses. In B. ericifolia this treatment doubled the number of inflorescences that set seeds, and increased by 40% the number of seeds produced per Inflorescence. Insecticide treatment did not alter either of these components of seed‐set in B. oblongifolia partly because the experiment began too late to exclude flower predators In this species. The results obtained for B. ericifolia support the hypothesis that flower and seed predators explain, in part, the low incidence of seed‐bearing cones and the low seed:flower ratios reported for many Banksia species.Each Banksia species supports two guilds of Inflorescence predators. Two Lepidopteran species feed on young flowers; one of these causes tunnel damage to the rachis. Each Banksia species also supports five Lepidopteran and two Curcullonid seed‐predators. About 40% of these herbivorous Insects are common to both shrubs.
Intersexual niche segregation among three bark‐foraging birds of eucalypt forests
Authors: NOSKE R. A. 
Published: July 2006

AbstractAll three species of specialized bark‐climbing birds in eucalypt forests of north‐eastern New South Wales exhibited sexual differences in their foraging behaviour. The degree of these differences was weakest in the least social species and strongest in the most social species, suggesting that intersexual niche segregation is an adaptation to reduce intraspecific competition for food. In the least social White‐throated Treecreeper, the slightly longer‐billed males foraged on dead branches more than females only during the breeding season when pair members were forced to share the same area. In the group‐living Red‐browed Treecreeper and Varied Sittella, males foraged lower and used rough‐barked trunks and limbs more than females throughout the year. Sexual differences in the foraging substrates of Sittellas may have been related to sexual dimorphism of the bill, but in the monomorphic Red‐browed Tree‐creeper, male dominance was probably important. Some evidence suggests that further subdivision of the niche may occur in the highly social Sittella along the vertical dimension according to age and/or reproductive status. This report argues that intersexual niche segregation is just as likely to develop under conditions of increased interspecific competition as under reduced competition.
Distribution of the immature stages of Aedes vigilax on a coastal salt‐marsh in south‐east Queensland
Authors: DALE P. E. R. , HULSMAN K. , HARRISON D. , CONGDON B. 
Published: July 2006

AbstractThe distribution of eggs and larvae of Aedes vigilax was studied on part of a coastal salt‐marsh in south‐east Queensland. At the macro‐scale (8 ha area), the largest numbers of larvae hatched were from samples taken in areas with relatively low open vegetation adjacent to drainage channels. Such areas are likely to be suitable for egg conditioning and hatching and are also accessible to adult mosquitoes. At the micro‐scale (the environs of two small pools), most hatching occurred in narrow bands at specific elevations from the pool bottom but the relationship with vegetation was variable. Failure to hatch larvae from samples taken at the start of, or during, the cooler months was thought to be associated with egg diapause. At the macro‐scale whilst the marsh was flooded, most larvae were found in two habitat types: the tall dense Sporobolus virginicus in relatively elevated locations and in depressions dominated by Sarcocornia quinqueflora. At the meso‐scale (on a 1.4 ha grid) the distribution of larvae was found to be further related to water movement. Most larvae were in areas of slower water movement and appeared also to be redistributed by tides.
Seasonal changes in the abundance and body condition of honeyeaters (Meliphagidae) in response to inflorescence and nectar availability in the New England National Park, New South Wales
Authors: McFARLAND DAVID C. 
Published: July 2006

AbstractSeasonal changes in numbers and body condition of honeyeaters were examined over 2 years in the New England National Park, New South Wales, Australia. Nectar availability measured as inflorescence density and nectar production were also recorded. In the main study site, the abundance of six of the seven most common species of honeyeater was significantly correlated with inflorescence density. However, honeyeater numbers were not significantly correlated with daily energy productivity. Unlike most honeyeater communities, the New England community was dominated numerically by the Eastern Spinebill, the smallest of the most common species present. Among the most common species, the duration of time a species was recorded in the area was negatively, but not significantly, correlated with its size. All species examined showed similar seasonal changes in body condition, with the highest bodyweights and fat deposits recorded in winter.