bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some aspects of acclimation to low temperatures in the grain weevils Sitophilus oryzae (L.) and S. granarius (L.)
Authors: EVANS D.E. 
Published: July 2006

Abstract The ability of Sitophilus oryzae (L.) and S. granarius (L.) to acclimate when transferred from 27°C, a near optimal temperature, to 15° C, a marginal temperature, was examined in terms of chill‐coma temperature, dispersal, oxygen consumption and rate of oviposition. The chill‐coma temperature of S. oryzae was higher and the increment of acclimation less than that of S. granarius. Acclimation, although well advanced after 2 weeks after transfer, took more than 4 weeks to complete. Re‐acclimation after the reciprocal transfer took only 2 weeks. The dispersal of S. oryzae held at 15 and 27° C prior to testing differed when the weevils were released in wheat at 27°C but not when released at 15°C. Cold‐acclimated S. granarius dispersed less than warm‐acclimated weevils when released in wheat at both 15 and 27°C. The activity oxygen consumption of cold‐acclimated weevils was less than that of warm‐acclimated weevils. Inverse‐shifts of acutely determined R‐T relationships appeared more significant than changes in temperature sensitivity. Acclimation to 15° C took 8–10 days and re‐acclimation to 27°C about 6–8 days. S. oryzae consumed less oxygen per unit of weight than S. granarius but was more temperature sensitive. Resting oxygen consumption, which was less temperature sensitive than activity consumption, also exhibited inverse acclimation in both species.S. granarius showed evidence of inverse acclimation of oviposition rate after acclimation at 15°C.
The relative injuriousness of insect pests of cotton in the Namoi Valley, New South Wales
Authors: WILSON A.G. L. , GREENUP L. R. 
Published: July 2006

Abstract The sequence and relative injuriousness of insect pests was studied for three successive years in unsprayed cotton of the Namoi Valley. Heliothis punctigera Wallengren, the native budworm, and to a lesser extent H. armigera (Hübner), the cotton bollworm, prevented the setting of full crops by destroying buds and bolls. After setting, high proportions of bolls were injured by Earias huegeli Rogenhofer, the rough bollworm. Incidental damage was caused to seedlings by Thrips imaginis Bagnall, the plague thrips, and lo leaves by Anomis flava Fabricius, the cotton looper, and by Austracris guttulosa (Walker), the spur‐throated locust. In commercial crops, pest control must rely on the use of broad‐spectrum insecticides: H. armigera is currently resistant to several of these, and has become the principal species in the local population of cotton pests.A number of enviromental features impede the natural control of pests in the southerly areas where cotton is now produced. In comparison to the older dryland cropping practised in central Queensland, a higher yield is necessary to cover the production costs of irrigated cotton; a shorter growing season prevents the plants from compensating effectively for insect damage and the natural enemies of cotton pests are less abundant and less active.
The distribution and density of rabbit warrens on the Southern Tablelands of New South Wales
Authors: PARKER B. S. 
Published: July 2006

AbstractRabbit warrens are distributed in a clumped manner in three areas totalling 1696 ha in the Southern Tablelands of New South Wales.While the discontinuous distribution may be partly related to original patterns of colonization, the present distribution is closely related to agricultural practices and the rabbits’biological requirements. The highest densities of warrens are in the agriculturally less valuable areas. The number of burrows in use in a warren is related to the number of rabbits living in the warren, although at the time of the study, large warrens contained fewer rabbits than expected.
Estimates of biomass in a temperate mangrove community
Authors: BRIGGS S. V. 
Published: July 2006

AbstractAbove and below ground biomass of Avicennia marina (Forsk.) Vierh. was studied in a mangrove community near Sydney, Australia. Data were obtained for seedlings (0–80 cm) and established trees (≥ 200 cm) growing in two nearby sites. Estimates were made of total mangrove biomass and its components: roots and pneumatophores; trunks and branches: leaves and petioles. The sites studied differed in average tree size (277 kg v. 97 kg) and in seedling biomass (0.12 km m‐2 v. 0.02 kg m‐2) but not in total biomass (29.2 kg m‐2 v. 27.3 kg m‐2).The partitioning of biomass of Avicennia marina in this temperate mangrove community was similar to that of Rhizophora mangle in a tropical mangrove community.
The determination of an optimum sampling technique for biomass of herbaceous vegetation in a Central Australian woodland
Authors: FRIEDEL M. H. 
Published: July 2006

AbstractThe green standing material, dry standing material and litter in the herbaceous layer of a Central Australian woodland were sampled using sets of nested quadrats of various proportions. By minimizing the product of the time required to obtain the data and the relative variances of the mean weights of material, the optimum size of quadrat necessary for estimating biomass was found to be 1 m2 or less. The optimum shape of quadrat for litter was a very elongate rectangle, with the lengths of its sides in the ratio 1:16. There was no preferred shape for green or dry standing material in this case.No edge effect was detected. A method is given for determining the optimum number of quadrats for a known mean, variance and cost.
Plant communities of the Mt Wellington Range, Tasmania
Authors: RATKOWSKY D. A. , RATKOWSKY A. V. 
Published: July 2006

AbstractAssociations among species of vascular plants in twelve predefined vegetation zones on Mt Wellington, Tasmania, are described. The vegetation zones were based mainly on the dominant species of eucalypt contained therein, following an approach used previously by Martin (1940). The twelve zones were subsequently reduced to a total of six cluster groups using hierarchical classification procedures. Character species, in the sense of the Braun‐Blanquet (1928) system of phytosociology, are identified and tabulated for each group. It is suggested that the division of a survey area into zones based upon dominant euealypts may be applicable to the study of vegetation communities in other parts of Tasmania.
Nutrient stocks in a subtropical eucalypt forest, North Stradbroke Island
Authors: WESTMAN W.E , ROGGERS R. V. 
Published: July 2006

AbstractThe concentrations and quantities of eleven essential plant nutrients in a 15 m tall Eucalyptus signata dominated forest have been determined. This forest of 180 habiomass is supported on one of the most phosphorus‐deficient forest soils yet reported. The ecosystem is also particularly low in calcium, and relatively abundant in nitrogen. The nutrient stocks in the sclerophyllous heath understorey are only slightly more than half the quantity expected on the basis of their proportion of the total forest biomass occupied by this stratum. This lends some confirmatory evidence to the idea that the heath understorey of eucalypt forests is a separately evolved synusia adapted to soils of low fertility. Partitioning of nutrients among plant parts on this forest differs in a number of respects from other forests studied. This suggests the lack of strong selective pressure towards convergence of strategy between formations in the manner of partitioning of nutrients among forest components.
Population structure of Livistona eastonii Gardn., Mitchell Plateau, Western Australia
Authors: HNATIUK R. J. 
Published: July 2006

AbstractLivistona eastonii on the Mitchell Plateau of northern Western Australia forms a dense, multi‐aged understorey to an open eucalypt woodland. The palm population has the characteristics of a species that comprises a climax vegetation type. Reproduction of the palm appears to have been stimulated in recent years, perhaps by annual burning. The present palm population has been reproducing throughout its life with only minor though significant fluctuations. The average maximum age is estimated to be about 280 years, based on an average increment of 2.85 cm/year for plants taller than 30 cm and 1.15 cm/year for the first 30 cm of height growth. Exceptionally tall plants of 21 m (Gardner 1923) and 10.4 in (Beard 1976) may be about 720 years and 360 years old respectively.
Seed germination studies with Heteropogon contortus
Authors: TOTHILL J. C. 
Published: July 2006

Abstract Germination characteristics of Heteropogon contortus were investigated in germination cabinets and in the glasshouse using soil trays. Under the former a dual inhibitory system appeared to operate. On the one hand naked caryopses from seeds which were less than 4 months of age were inhibited from germination by a process apparently analogous to epicotyl dormancy. This could readily be broken by applying 1% gibberellic acid and partly broken by repeated wetting and drying. On the other hand between 4 and 12 months, naked caryopses germinated more readily than intact seeds (caryopsis plus glumes, lemmas, etc.). However, the dormancy factor apparently associated with these structures could not be detected when seed was germinated in soil in the glasshouse and it appeared that they are a necessary protection for the caryopsis under field conditions.The optimal temperature for germination was between 30 and 35°C constant. Alternating diurnal temperatures of less than this appeared to cause reduced germination, and no high‐temperature stimulation was observed. Germination was not directly promoted by the passage of a normal grass fire.
Elimination of species before cluster analysis
Authors: STEPHENSON W. , COOK S. D. 
Published: July 2006

AbstractPrevious attempts at selecting species to eliminate are criticized and a method depending upon interspecific dissimilarities is outlined. It was tested using a matrix of 24 samples by 71 species, and shown to be viable and much more economical to operate than an alternative method which was developed and discarded. It still involves the arbitrary choice of a cut‐off level, and a parallel consideration of abundance values is advised.The method was assayed by performing cluster analysis with and without exclusion of species.
Studies of a vegetation transect through brigalow (Acacia harpophylla) forest in central Queensland
Authors: JOHNSON R. W. 
Published: July 2006

Abstract Vegetation and environmental data were collected in 182 contiguous plots along a belt transect, 3.7 km long, in central Queensland through a relatively undisturbed forest dominated by brigalow (Acacia harpophylla). A subset of eighty‐nine plots using percentage cover of 128 species was classified using a polythetic agglomerative approach. Dual stand and species ordinations by principal component analysis and reciprocal averaging were also undertaken. The cluster analysis and ordination of unstandardized cover data, grouped stands on the basis of abundance of the predominant canopy species, but only where these species were true dominants such as Macropteranthes leichhardtii did these same groupings appear in the ordination of standardized data. The latter ordination was ecologically more satisfying, but the complementary species ordination was unsatisfactory. The vegetation‐species complex was best explained by dual species and stand ordinations using presence‐absence data. Reciprocal averaging appeared to produce a marginally better ordination than principal component analysis.An ordination of eleven environmental factors indicated soil profile and presence of gilgai were the most important environmental variables. The ordination was enhanced by varimax rotation which focused on a more homogeneous environmental gradient and coincided more closely with the vegetation ordinations. An ordination using both species and environmental factors substantiated the explanation of the vegetation‐environmental complex derived from separate ordinations. The main gradient revealed from the ordinations appeared to be a mesic‐xeric gradient stretching from Macropteranthes leichhardtii semi‐evergreen vine thicket at the mesic end diverging through various A. harpophylla ‐ dominant communities to A. harpophylla ‐ Eucalyptus melanophloia woodland on duplex soils and Dichanthium affine grassland on clay soils. Six plant communities are defined and described and each related to a particular set of environmental conditions. These communities are bonewood (Macropteranthes leichhardtii) ‐ semi‐evergreen vine thicket, brigalow (Acacia harpophylla) ‐ semi‐evergreen vine thicket, brigalow (A. harpophylla) continuum (clay soils), Dichanthium affine grassland, brigalow (A. harpophylla) continuum (duplex soils) and brigalow (A. harpophylla) ‐ silver‐leaved ironbark (Eucalyptus melanophloia) woodland.
Biomass and nutrient distribution in two eucalypt forest ecosystems
Authors: FELLER M. C. 
Published: July 2006

Abstract The distribution of biomass and nutrients (N, P, K, Na, Mg, and Ca) among components of a Eucalyptus regnans forest and a mixed Eucalyptus obliqua‐Eucalyptus dives forest near Melbourne in southern Victoria have been determined and are discussed. Both forests were found to have relatively low root biomass. Trees and soil accounted for more than 80% of each nutrient present in both ecosystems. The results of nutrient distribution studies in Australian eucalypt forests and in temperate forests elsewhere in the world are compared. These comparisons suggest that the above‐ground living biomass in eucalypt forests contains no abnormally high or low quantities of macronutrients in relation to coniferous or deciduous hardwood forests. Detailed comparison among ecosystems is rendered difficult by the variable treatment given to roots and soils.
The foraging behaviour of Australian honeyeaters: a review and some comparisons with hummingbirds
Authors: PYKE GRAHAM H. 
Published: July 2006

AbstractThe foraging behaviour of Australian honeyeaters is reviewed in terms of diet, foraging selectivity, foraging flight mode, quality and quantity of nectar encountered per flower, flower densities encountered and effect of predation. At the same time comparisons are made between honeyeaters and hummingbirds. These two groups of birds are superficially similar. Both feed on nectar and insects. Both tend to have long curved bills and tongues adapted for removal of nectar from flowers. Both tend to feed at long, red flowers. However, on close inspection, honeyeaters and hummingbirds are quite dissimilar. For example, many honeyeaters include fruit in their diets. Hummingbirds almost never eat fruit. Honeyeaters appear to be considerably less nectarivorous and more insectivorous than hummingbirds. Honeyeaters are, for the most part, larger than hummingbirds and they usually perch while feeding whereas hummingbirds usually hover. Honeyeaters but not hummingbirds often flock while feeding. Predation appears to be considerably more important for honeyeaters than for hummingbirds. Territorial defense of flowers seems common in hummingbirds but uncommon in honeyeaters. These differences are discussed in detail and explanations are offered for them wherever possible.
Studies in the analysis of data from Australian tidal forests (‘Mangroves’). I. Vegetational sequences and their graphic representation
Authors: BUNT J. S. , WILLIAMS W. T. 
Published: July 2006

AbstractDifficulties have been experienced in reconciling field observations of tidal forests in north‐east Queensland with published accounts of their vegetational character. Modern classificatory techniques have been applied to information on forest composition at 803 widely‐distributed sites. A novel method has been developed to represent a set of thirty association groups linked through a minimum spanning tree. This approach has provided new insights into tidal forest expression, the range of vegetational sequences present, and their relationships. Current views of mangrove zonation in north‐east Queensland are found inadequate.
Studies in the analysis of data from Australian tidal forests (‘Mangroves’). II. The use of an asymmetric monothetic divisive classificatory program
Authors: WILLIAMS W. T. , BUNT J. S. 
Published: July 2006

AbstractAn algorithm (ASYM) is defined which implements a monothetic divisive classification of presence/absence data; it is based on the Jaccard measure and is consequently asymmetric, in that it ignores double‐zero matches. It is insensitive to group size but sensitive to floristic heterogeneity. An extensive set of Australian tidal forest data is processed both by ASYM and by the symmetric information‐statistic divisive program DIVINE. It is concluded that the two systems are complementary in that they reveal somewhat different aspects of the data‐structure; but that if only one program were to be used, ASYM would be ecologically preferable.
The cation composition of precipitation at four sites in far north Queensland
Authors: BRASELL H. M. , GILMOUR D. A. 
Published: July 2006

Bulk precipitation samples were collected over four years at four sites on a transect from the Coral Sea to the Atherton Tableland in far north Queensland and analysed for sodium, potassium, calcium and magnesium. The concentration of the cations in the rainfall was significantly higher during the dry season than during the wet season. There were marked differences between the coastal sites and the Tableland sites in both concentration and accession of cations in the precipitation. Mean annual accession for sodium, potassium, calcium and magnesium ranged from 159, 8.1, 17.1 and 19.4 kg/ha respectively at the coastal sites to 11, 4.5, 2.7 and 2.4 kg/ha respectively at the Tableland sites. The high levels of cation accession at the two coastal sites was attributed to the very high annual rainfalls.There were no differences in ionic ratios between seasons except for the most inland site. However, there were significant differences in ionic ratios between coastal and inland sites. except for Na: Mg, with increasing proportions of calcium and potassium and decreasing proportions of sodium and magnesium away from the coast.
The ecology ofAraucariaspecies in New Guinea. I. Ordination studies of forest types and environments
Authors: ENRIGHT N. J. 
Published: July 2006

AbstractPrevious studies of the ecology and regeneration strategies ofAraucaria cunninghamiiandA. hunsteiniiin New Guinea rainforests have treated these species as ecologically identical and disagree concerning their ability to maintain a stable population size in forest communities dominated by angiosperms. Vegetation data from a number of 0.5 ha forest sites in New Guinea are analysed in order to characterize forest types and their environmental regimes in the altitudinal zone from 700 to 1500 m a.s.l. Particular attention is paid to forests containing Araucaria species. Nodal component analysis identifies a number of distinct forest types or ‘series’, each dominated by a different species. Continuity analysis displays the location of sites and species in non‐linear ordination space.Subsequent regression of environmental data on the position of sites in ordination space shows that forest types are separated along gradients related to altitude and rainfall on the one hand, and soil nutrient concentrations on the other.A. cunninghamiiis generally found in wetter and less nutrient‐rich sites thanA. hunsteinii.The analysis of species presence data, as opposed to quantitative data, shows that whilst forest types are easily differentiated according to their dominant species, changes in floristic composition are subtle along the altitudinal and other gradients recognized.
Seed dispersal in a cycad, Macrozamia riedlei
Authors: BURBIDGE ALLAN H. , WHELAN ROBERT J. 
Published: July 2006

Abstract The influence of animals on patterns of seed dispersal has not been well explored, despite the importance of seed dispersal in plant population biology. Furthermore, the exploitation of animals as dispersal agents has been considered one reason for the replacement of gymnosperms by angiosperms in the Cretaceous. We studied seed dispersal in a cycad, Macrozamia riedlei, and showed that in the absence of animals, ripe seeds drop directly beneath the parent not more than 40 cm from the base. Several animals eat the fleshy outer integument of the seeds, and possums (Trichosurus vulpecula), transport seeds up to 24 m from the parent. The postdispersal positioning of seeds gave a log density‐log distance relationship of y = 7.20 – 2.85x (r2= 0.96, N = 17). Effective local dispersal may have contributed to the persistence of cycads in the world flora for the last 200 million years.
Patterns in north Queensland mangrove vegetation
Authors: BUCKLEY R. C. 
Published: July 2006

AbstractThis note suggests an additional interpretation of analyses of north Queensland tidal forest vegetation recently presented by Bunt & Williams (1980a). They separated 30 species associations defined by various combinations of 11 defining species, and showed that these associations do not form a single invariant zonal sequence, as implied previously by Macnae (1966). Their results do indicate, however, that individual mangrove species are characteristically associated with different sections of the overall tidal range. This does not contradict their conclusions but rather places a different emphasis on their results.
Ecological association of birds and vegetation structure in wet tropical forests of Australia
Authors: KIKKAWA JIRO 
Published: July 2006

AbstractBirds and environments of tropical rainforests were studied in 18 selected areas from sea level to 1520 m within the humid tropical region of northeastern Australia. A total of 122 sites (20 m × 20 m each) were established within the 18 areas, and bird data (observation and mist‐netting) and environmental data (pro forma survey and foliage measurements) were collected at each site. The bird data were analysed numerically in two ways: abundance of 146 species in 18 areas and presence and absence of 108 species at 122 sites. Both classification and ordination analyses produced a major discontinuity between the tableland sites and the lowland sites, each divisible further into various types of vine forest and non‐vine forest vegetation. The few rare species did not contribute to the general pattern. The environmental data were reduced to a set of those attributes that showed variation among the sites. They included topographic and edaphic features, physiognomic and structural features of vegetation, fruiting and defoliating habits of plants, foliage height diversity and evenness, and canopy cover. The primary pattern in the data set of 135 attributes by 122 sites was vine forest versus nonvine forest, and altitudinal divisions appeared as a secondary pattern, in both classification and ordination.Canonical correlation coefficients between bird vectors and environmental vectors were reasonably high for the first four canonical vectors, which correlated well with major Gower vectors of birds and environments. The back‐correlation to the raw data produced bird species and matching environmental attributes with sites sharing them for both positive and negative ends of each canonical vector. In general, the analysis extracted elements of both fauna and environment that characterized the vine forest as opposed to the non‐vine forest and the tableland sites as opposed to the lowland sites. Canonical correlation analysis is limited by the unverifiable nature of derived correlations. Such correlations may suggest certain associations to be tested by independent means (hypothesis‐generating function), but may also formalize self‐evident or fortuitous associations.