摘要:

AbstractExisting strategies for species‐reduction in data matrices from species‐rich communities are critically reviewed, and a new method is proposed. It is based on a two‐parameter model; each species can be associated with an ‘eident value’, which is a measure of the extent to which that species discriminates between site‐groups. The method is applied to a small segment of agronomic data, and to a rainforest survey, and in both cases is shown to produce meaningful results. Application of the method promises greatly to reduce the computing time currently needed for two‐parameter analyses, and therefore to allow more extensive search techniques t

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1978.tb00848.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractAn ecological comparison, with special reference to tropical affinities, is made between the rain forests of New Zealand and south‐east Australia, based on the distribution of seventy physiognomic‐structural attributes in mature forests at selected sites (ten in New Zealand, twenty in Australia, and four in New Guinea to represent authentic humid tropical lowland rain forest). The structural data were recorded in a standardpro formaand subjected to classification, ordination and two‐parameter analysis.In the classification, the Australian and New Zealand sites, with two exceptions, separated at the four‐group level. The more complex (cool subtropical) Australian types were the least related to the New Zealand forests, which are closest to Australian simple (submontane) types. There was a similar distinction in the ordination, in which the trend along the first two vectors was latitudinal, correlated with extremes of temperature and with moisture availability.The relative contributions of the structural attributes to the various site groupings in the classification and ordination are enumerated, and provide an objective scale of comparison of the forests. Structural attributes designated by analysis as exclusively or preferentially tropical by reference to the New Guinea sites are then used to assess degree of tropical affinity.The simplified cool temperate (montane) forests dominated by one species ofNotho‐fagusin New Zealand and Australia are closely related. The Australian forests of the sub‐montane zone (mean annual temperature 12–15° C) which are typically dominated by Ceratopetalum apetalum, Nothofagus mooreiorDoryphora sassafras, are similar to the podocarp‐broadleaf forests, with or without kauri, of New Zealand. The Australian forests of the cool subtropical zone (mean annual temperature 15–17°C) which have mixed dominants, have some affinities with the kauri‐podocarp‐broadleaf forests of North Auckland. In New Zealand, a broadleaf type in which kauri is absent or rare on basalt in North Auckland (lat. 35° S) was the most complex forest sampled and i

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1978.tb00849.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe aquatic vegetation of three sites on the Atherton Tableland is described and analysed with the aid of numerical classifications. Despite major physiognomic differences in the vegetation between sites, four floristic groups are recognized which can be related to major habitat types. Water depth and seasonal fluctuations in water level are suggested as the main factors controlling vegetation distributions in the absence of disturbance by biotic agencies. Species characteristic of particular aquatic communities are identified and these could prove useful in the recognition of hydroseral stages in pollen diagrams constructed from these sites and in the determination of past lake levels.

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1978.tb00850.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractBlock fields and block streams above 1000 m on Mt Wombargo and Mt William, in northeastern and western Victoria respectively, were found to be in various stages of colonization. Plant succession was influenced by slope, altitude, precipitation, fire and the nature of the boulder accumulation. Lichen colonization was abundant on exposed surfaces. Soil build up, which commenced at deeper levels amongst the boulders, was hastened by the development of moss mats, and in particular by the accumulation of litter from adjacent eucalypt forest and woodland.

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1978.tb00851.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe reaction ofEmex australisto different degrees of stress was examined in a pot experiment by varying pot size and in a field experiment by varying density. In pots, the proportion of energy in seeds was more stable to the imposition of stress than in roots and stems; that in roots increasing with increasing stress and that in stems declining. Similarly in the field, there was little difference between densities of 1–32 plants m−2in the proportion of seeds in biomass. There were no significant differences in mean individual seed weights in either experiment and all plants set seed.Again in both experiments, high stress plants were more precocious than low stress ones. In pots, this took the form of earlier attainment of maxima in calorific values, ‘reproductive effort’, root, stem and seed weights and in the field, a shorter life cycle and earlier senescence. In pots, estimates of the overall mean reproductive effort were 62% for the low and medium stress plants and 36% for the high stress plants. The results are discussed in terms of the high values for reproductive effort, the plasticity and precocity ofE. australisunder stress and the implications for weed

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1978.tb00852.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractInteracting effects of phosphorus, potassium and sodium on the growth and nutrient uptake inStylosanthes fruticosawere studied in its native sandy soil and solution culture. High phosphorus in the medium had adverse effects on growth. High potassium level completely masked or lessened adverse effects of high phosphorus. High sodium level adversely affected growth only in combination with high phosphorus and low potassium. Shoot nutrient content data indicated that phosphorusper semay not inhibit growth. Selective uptake of potassium against sodium was eliminated by high phosphorus. It is suggested that high concentration of phosphorus in the medium effects membrane permeability and the effect of phosphorus on plant growth is primarily through its influence on uptake of other ions.

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1978.tb00853.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe shallow macrobenthic communities of Wallis and Smiths Lakes on the central N.S. W. coast have been studied by replicate grab samples. Wallis Lake is a coastal marine lagoon constantly open to the sea, whereas Smiths Lake, also a coastal lagoon, is periodically closed to the sea for several months at a time. The benthic communities were described using indices of dominance and diversity. Between site communities were compared usingMULTBETand aGOWERordination. Generally, sites in Wallis Lake had a more diverse fauna than those in Smiths Lake. Weed beds supported more species and individuals than sandy substrates. The benthic fauna of these two lakes is compared with other coastal rivers and lagoons which have been studied in temperate eastern Australia.

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1978.tb00854.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractFifty‐seven epiphytic species were found to occur on the two sea‐grass hostsZosteraandPosidoniain Botany Bay and Jervis Bay, N.S.W. Among the algal epiphytes onPosidonia australisseveral indicator species were identified and it was found that their relative frequency of occurrence can be used to differentiate sites within the two bays. These indicator species can be used also to classify a collection from an unknown site within the region, and their relative occurrences may provide a useful index for early detection of changes in the bay environme

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1978.tb00855.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe diet of foxes living in a mixed dry sclerophyll forest at Naringal East near Warrnambool, Victoria was investigated by analysis of scats collected between October 1972 and July 1975. The results indicate that foxes in the study area are opportunistic feeders whose diet consists mainly of rabbits despite the abundance of suitably sized native mammals and an even greater abundance of birds. During summer and autumn the foxes consume large numbers of insects, particularly the black cricket,Gryllus servillei, and the Australian plague locust,Chortoicetes terminifera, and blackberries.

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1978.tb00856.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractHabitat preferences of five species of small mammals were studied on a 6.6 ha trapping grid in heathland on an undulating, deep, sandy podzol at Cranbourne, Victoria. The 120 sites were sorted into groups using a polythetic, agglomerative, non‐hierarchical clustering procedure with (i) floristic and (ii) structural data. The dispersion of 4051 trap captures over 28 months was studied in relation to these groupings.Rattus lutreolusshowed no preference for any of the structural groups, but good differentiation was obtained with the floristic groups. Dispersion ofR. lutreoluswas related to a sedge‐food index, and seasonal change inR. lutreolusdispersion was related to change in rainfall. The preference ofR. rattusfor areas of wet heath of high structural complexity was best revealed using the structural classification. The results for the other species tended to favour the floristic rather than structural groups. Pseudomys novaehollandiae and Isoodon obesulus preferred dry heath of a younger successional stage.Mus musculuscaptures showed a preference for the dry heath generally. This preference was most pronounced in spring when the population was declining.The wet community species(R. lutreolus, R. rattus)tended to be food specialists and habitat generalists and the dry community speciesP. novaehollandiae, I. obesulus, M. musculus), exhibited converse tra

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1978.tb00857.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY