摘要:

AbstractThe terrestrial lizard fauna of a regenerating mining path situated in open forest on coastal sand dunes was surveyed by pitfall trapping. The regeneration age of the series of chronosequence plots used ranged from 3.9 to 15.9 years. No lizards were recorded on plots less than 5.9 years old. Only four species of lizard were regularly found on the mining path. The skinkCtenotus robustuswas the first colonizer and attained peak abundance and biomass after 9 years’ regeneration.Amphibolurus muricatusandCtenotus taeniolatuswere less abundant thanC. robustusand did not appear on the mining path until 9 to 11 years’ regeneration. The abundance ofC. taeniolatuscontinued to increase up to the oldest age class (16 years). Linear multiple regression analysis showed that sparse patchy vegetation in the 0–1 m layer and the amount of live shrub cover jointly accounted for 72% of the variance in abundance and 68% of variance in biomass forC. robustus.Fifty percent of the variance inC. taeniolatusabundance was explained by the proportion of plant species endemic to forest, regeneration age and the patchiness in understorey vegetation height. However, 67% ofC. taeniolatusbiomass was accounted for by plant species richness, plant species diversity, and the proportion of endemic forest and heath plant species. Some lizard species recorded from the surrounding forest were not found on the mining path. Lizards appear to recolonize revegetated areas more slowly than some other animal groups; this ‘sensitivity’ implies that they can act as important ‘indicator species’ of successful regeneration in disturbed areas. The non‐linear response with time of some habitat variables makes it difficult to predict the time required for the complete rehabilitation of the mining path; however, it seems likely that a period well in excess of 20 years may be necessary before the lizard fauna on the mining path reaches

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1991.tb01041.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractPodocarpus lawrenceiis a native conifer which normally occurs as a shrub in alpine, and less often in sub‐alpine, communities in New South Wales, Victoria and Tasmania. A disjunct and unusual distribution occurs at Goonmirk Rocks, in north‐east Victoria, in a montane, wet forest environment in whichP. lawrenceigrows as a procumbent and sometimes vertical tree up to 13 m tall. The communities in whichP. lawrenceioccurs at Goonmirk Rocks are described, and the population structure ofP. lawrenceiis determined using an age class model. Measurement of light regimes and of the nutrient status of these communities indicate differences between areas of active regeneration and those with none, and between forest types that do supportP. lawrenceiand those that do not.P. lawrenceiis determined to be a stable component of the vegetation of Goonmirk Rocks, where it attains its best development on the margins of cool temperate rainforest where a broken canopy and the long‐term absence of fire allow it to develop into a low scrub with simple floristics. A community fire history is reconstructed using the age class model, fire scars and the age ofAcacia dea

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1991.tb01042.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractGerminable seed densities in the surface (0–10 cm) soil of pasture communities growing at Lansdown, near Townsville, were measured during the late dry season before the first germinating rain and again during the following wet season after germination but before the input of new seed. Seedlings emerging in the field were counted at approximately weekly intervals during this period to determine emergence patterns. Twelve communities were sampled in 1980–81 and six were re‐sampled in 1981–82.During the late dry season germinable seed densities ranged from 5000 to 40 000 seeds m‐2. Seeds of the introduced legume,Stylosanthes hamata, were present in all pastures. There were many seeds of annual grasses (Digitaria ciliarisandBrachiaria miliiformis) and sedges (CyperusandFimbristylisspp.) but only few seeds of perennial grasses (both native and introduced). Soil seed densities were much lower during the wet season than during the preceding dry season, particularly for the grasses.Emergence commenced and approximately 70% of all seedlings emerged on the first major rainfall of the wet season. The subsequent emergence pattern varied between years. In 1980–81 there was a gradual and continuous increase in seedling numbers under the continuously moist conditions which prevailed. In 1981–82 further emergence occurred in discrete events related to rainfall and intervening dry periods. Maximum seedling densities exceeded 34 000 seedlings m‐2including 29 000 grass seedlings (mainly annual species).The implications of these results for species survival and pasture compositio

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1991.tb01043.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractHoney bee hives were placed, during two consecutive summers, in an experimental site which contained natural and artificially placed colonies of Exoneura asimillima, a semi‐social, native bee. Two classes of colonies were studied: founders, and established colonies. Nests and contents were collected from an experimental site and three control sites following several months of exposure at the experimental site to the apiary honey bee population. Nest contents were analysed for differences among sites in colony population parameters which could have been caused by resource competition with introduced honey bees. Colony founding and overall colony survival were also considered.During the first season, the average number of large larvae plus prepupae per colony was significantly higher in the experimental site than in the control site. This difference could, however, have been the result of a two‐week gap in sampling all the sites. All nest parameters showed high variability and there were no other significant differences between the two kinds of site.In the experimental site during the second season there were, relative to the control sites, significantly fewer total numbers of adult males and females in established nests and in all nests combined, significantly more immatures of all stages in founder nests and significantly lower adult male:female ratio. Although preliminary in nature, the data suggest that, in the experimental plots, E. asimillima showed: (i) increased adult emigration, (ii) increased brood rearing success, and/or (iii) relatively later colony founding, compared to the three controls. The possibility of resource competiton with honey bees causing the observed changes is discussed, along with alternative explanati

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1991.tb01044.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe effect of plant age up to 85 days on the resistance to trampling and recovery ofCynodon dactylonandLolium perennewas examined quantitatively in a glasshouse experiment. Simulated trampling treatments were initially applied to these plants at six different time intervals based upon age: 5, 15, 25, 45, 65 and 85 days after seed germination. Resistance of both species to trampling was found to increase with age. Overall, the recovery of C.dactylonalso increased with age whileL. perenneshowed no significant difference in recovery as age increased. Resistance ofL. perenneto trampling was higher than that ofC. dactylonat all six ages while the recovery ofC. dactylonfrom trampling was greater than that ofL. perenne at all six ages. In conclusion, trampling can be considered as an important factor affecting the establishment of seedlings.

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1991.tb01045.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractEucalyptus paliformisis a rare species of the Wadbilliga Plateau in southeastern Australia. The hypothesis that rarity inE. paliformisis a result of restriction to a rare habitat was addressed by means of a floristic survey comparing sites whereE. paliformisoccurs with similar sites where it is not known to occur. Mathematical models describing mean annual rainfall and mean annual temperature regimens experienced in southeastern Australia were used to locate areas with a climate similar toE. paliformissites. Understorey vegetation ofE. paliformissites was then compared with that of climatically similar areas using a stratified random sampling procedure. Similarity in floristic composition was used as an integrated measure of habitat similarity. Detrended correspondence analysis of the floristic data suggested thatE. paliformissites are unique. No single environmental factor was sufficient to describeE. paliformissites—rather, their peculiarity could be ascribed to a unique combination of environmental factors. Within the Wadbilliga area, temperature or moisture parameters relating to marginally higher elevation or low relative radiation index may be important. Non‐metric multidimensional scaling of the floristic data revealed similar environmental trends in the data, but support for habitat peculiarity inE. paliformiswas wea

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1991.tb01046.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe rate at which ant nests relocate may affect the fate of ant‐dispersed seeds by influencing nutrient and seed accumulation in localized areas. In this study, the movement of ant nest entrances was monitored in fixed quadrats in dry sclerophyll woodland in Kuringai Chase National Park, NSW. Changes in entrance location were rapid for most species, with few entrances remaining in use for more than 6 months. Approximately 30% of entrances that closed were subsequently re‐opened. There was no obvious seasonal pattern in entrance relocation. After 1 year, between 5 and 40% of the ground surface of the quadrats had been within 10 cm of a nest entrance. New nest entrances did not cluster near old entrances, indicating that nest entrance relocation may be accompanied by changes in underlying nest structure. Nutrient levels in soil samples from active nests ofRhytidoponera metallica, Aphaenogaster longiceps, Pheidolesp. 1 andIridomyrmexsp. 8 did not differ significantly from random locations.The rapid changes in entrance location and the lack of nutrient enrichment may be the result of continual and progressive underground shifts in nest location. Such shifts have three potential consequences for seeds that remain buried within the nests. First, seeds will not benefit following germination by being in a nutrient‐rich microsite. Second, a proportion of seeds collected by harvester ant species may escape predation if left in an abandoned section of the nest. Third, concentrations of seeds in localized areas may be reduced, leading to a reduction in competition between establishing seed

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1991.tb01047.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractA state‐wide survey of the endemic Tasmanian podocarpLagarostrobos franklinii(Huon pine) resulted in the recognition of four major community types largely restricted to the river systems of western and southern Tasmania. Continuous variation was found between most of these communities. The floristic variability was found to be correlated with temperature, rainfall and geological gradients. It is suggested that the restricted nature of Huon pine distribution in Tasmania is associated with a slow terrestrial dispersal rate rather than a narrow fundamental niche. There is some evidence to suggest that the species has been further restricted by fir

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1991.tb01048.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractAnalysis of stand structure and spatial patterning indicates thatLagarostrobos franklinii(Huon pine) regenerates intermittently in response to canopy disturbance. Its ability to resprout rapidly from fallen trees is likely to be important in the continued dominance of gaps by this species in competition with faster‐growing tree species. The largely riverine distribution pattern of this species is best explained by rapid vegetative spread down river systems and slow dispersal into canopy gaps away from river edges. The probability of recurrent disturbance within the lifespan of this species is high, implying that competitive exclusion of Huon pine is unlikely once it establishes at a sit

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1991.tb01049.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractShallow subtidal areas of rocky reefs in central and southern New South Wales may best be described as a mosaic of habitats, the distributions of which are seemingly related to depth, wave exposure and a number of biological processes, particularly herbivory. The Fringe habitat is generally found only in the most shallow waters. Forests of the laminarian algaEcklonia radiataare often found at intermediate depths. In deeper, or more sheltered water, sponges, ascidians and red algae are more abundant and the abundances of sea urchins and other invertebrate grazers decline. Overlying this broad‐brush pattern are patches of crustose coralline algae (the Barrens habitat), the distributions of which are not clearly related to depth. Invertebrate herbivores, and sea urchins in particular, are abundant in the Barrens habitat. The Barrens habitat was most represented at the more southern locations. At the two most northern locations, reefs were shorter in length and dominated by ascidians (Pyuraspecies

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1991.tb01050.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY