摘要:

AbstractSimple models were developed empirically to account for possible effects of patchy annual predation upon populations of benthic species. Long‐term population cycles were generated and, provided there was limited interaction among three prey species, three different cycles were obtained. With exponential or power increments in populations, the prey showed spatial aggregations, but these were less marked than those observed in nature. The failure of the models to explain certain other natural phenomena is commented upo

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1981.tb01490.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractDifferences in the litter and soil of northern temperate and tropical and subtropical forest soil and soil faunas are noted. Analyses of the distribution and abundance of Cryptostigmata and Mesostigmata mites in the litter and soil of two Australian subtropical forests are presented. The faunal associations in the litter and soil of these forests are different. It is suggested that the litter and soil habitats of subtropical and tropical forests should be regarded as separate but connected habitats in relation to their fauna. This contrasts with the assumption, for temperate forests, that litter and soil communities are portions of a single system.

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1981.tb01491.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe food preference ofDindymus versicolor(Herrich‐Schaffer) is tested and discussed in regard to the pest status and pest potential of this species. By proposing a mathematical model, the validity of determining a preference ranking using a series of dual choice experiments is verifie

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1981.tb01492.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractClearing of native forest has caused a rise in soil watertables and increased the salinity of land and streams in south‐western Australia. Reforestation is a possible method of increasing the use of water on cleared catchments, lowering watertables and reducing the output of salt from hillside seeps. One of the first needs is evidence of suitable species for such a project. This paper describes the comparative success of twenty‐eight species (mainly Eucalyptus spp.) in establishment and early growth when grown on and near saline seeps during 1976–77. Plantations were located in 850, 500 and 420 mm annual rainfall zones of the Hotham River valley about 150 km south‐east of Perth, Western Australia. The sites had saline confined aquifers and seasonal perched watertables which were typical of many landscapes in the region.Though rainfall was below average and only one watering was given, nineteen species had greater than 80% establishment in upslope, midslope and downslope positions. In late winter 1977, 15 months after planting, the leading species were 1–2 metres tall and carried leaf area up to 5.5 m2per tree where current rainfall was highest. The results indicate a high potential for plant establishment and early growth within the rainfall zones.Eucalyptusspp. from many regions of southern Australia were successful at the wettest location. Success at the two driest locations was limited to species from dry climates of southern South Australia and Western Australia.Planting on seep areas decreased the establishment of three species.Eucalyptus wandoo, E. globulusandE. camaldulensis, which performed well on non‐seep areas at one or more locations.Implications for a source of further test species and for planting strategy near seeps ar

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1981.tb01493.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractBelt transects taken over the main sandridges in Uluru National Park, Northern Territory, show a consistent fioristic zonation from swale to dunecrest.On the larger ridges five or six zones are distinguishable and the crest assemblage is largely disjunct; on the lower dunes the pattern is truncated.The Uluru dunefields are representative of the Northern Territory and central Western Australia, though the floristic assemblage differs regionally.

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1981.tb01494.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThis is the third of a series of papers describing the soils and vegetation of the central Australian sandridges and their interrelations. It details topographic—floristic patterns on fourteen transects at seven sites in the northwest, southwest and southeast Simpson Desert.There is a consistent vegetational zonation on the main Simpson sandridges, with regional modifications due to the broad scale NW‐SE floristic gradient. Closer dunes have more similar vegetation than distant ones. Swale vegetation is less consistent than sandridge vegetation and depends on soil type.Species differ greatly in their degree of restriction both topographically and geographically. Zone separation differs greatly between dunes in consequence. Zones defined on overall floristics are less clearly separated in the Simpson than in the western deserts. A floristically and structurally distinct crest zone is recognizable on all main dunefield sandridges. The only universally applicable zonation is swale, flank, crest.Vegetation patterns are more closely correlated with field soil texture than with topogra

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1981.tb01495.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA survey of 20 km2of species‐rich kwongan (sclerophyllous shrubland or sandplain vegetation) is reported, A total of 429 vascular plant species were found, of which 338 were recorded at the eighty‐seven systematically located 0.1 ha releves, Five vegetation units were defined following analysis of the site floristics data. Small but distinctive suites of species (totalling 26% of recorded species) characterized a gradient in soils from the sands and gravels of the lateritic uplands, through the deep sands of the dune sequence, to the clays of the winter‐wet depressions. However the soils‐related axis in the ordinations accounted for only ca. 6% of the variability in the data, indicating the complexity of the vegetation environment interactions. Species richness was greatest in a zone of apparent overlap between the lateritic group of species and those of the deep sand areas. The winter‐wet areas were poorest in species. The distributions of the floristically defined vegetation units did not closely parallel those of physiognomic units defined by interpretation of air photos. Structural dominance was negligible in all but the winter‐wet areas and the few dominants appeared poorly correlated with other species and with the physical environment. Comparisons are made with areas of similar vegetation elsewhere in Australia and in S

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1981.tb01496.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractLong‐term variations in the intertidal algal flora of the entire rock platform at Plantation Point, Jervis Bay, are described by May (1981). The study now reported presents similar long‐term changes in the flora of a subtidal region of the same headland, observed within the same period of time.This first detailed report of subtidal macroalgal communities in New South Wales describes a several‐year study of the benthic communities along a transect in the upper sublittoral region of a rocky headland at Plantation Point, Jervis Bay.Eighty‐nine species of algae were recorded, five of which were previously unrecorded for New South Wales.The area studied is dominated by the large brown algaeEcklonia radiataandPhyllospora comosa, large areas of which were cleared periodically by storms. Turf, shade and crustose coralline algal communities also were present.Storms, seasonal variation and longer term changes all affected the abundance and distribution of the algal species growing along the transect and hence the floristic composition of t

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1981.tb01497.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe clearing of native forests for open cut mining for bauxite is a potential cause for severe modification of the hydrological cycle. In the Darling Range, Western Australia, jarrah (Eucalyptus marginata Sm.) woodlands are being cleared for mining and are being replaced with plantations of other eucalypts.The plantation trees, which were up to 8 years old, showed no greater water stress than those of the original forest. The leaf area index of older plantation trees was usually higher than that of the original, mature forest. Transpiration rate was estimated on twigs enclosed briefly in a transpiration chamber. Prior test showed that this method was appropriate for comparisons in field grown eucalypts. Field measurements of stratified samples showed little difference in transpiration rate per unit leaf area between plantation forests and original forests. For the last 3 months of the dry season, however, transpiration per unit area of leaves was depressed by 25% in the plantation forest.

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1981.tb01498.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1981.tb01499.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY