bluuebunny/crossref_metadata_2025 huggingface dataset:
Robustness of demographic estimates in studies of plant responses to fire
Authors: MORRISON DAVID A. , CARY GEOFFREY J.
Published: July 2006

Abstract
For demographic models of resprouting species in relation to fire regimes, spatially separated populations of different ages are usually treated as a chronosequence, and the average behaviour of these populations is used as the estimate of the generalized behaviour of a single population through time. Using the data of Bradstock (1990), we examine the way in which the between‐population variability affects the demographic parameters for Banksia serrata (Proteaceae) and thus assess whether the estimates of the shortest inter‐fire interval necessary to maintain a stable population size under low and high intensity fires are robust to variation in these parameters. The range of our estimates compares well to the average estimate of Bradstock (1990) for high intensity fires, but not for low intensity fires. However the relevant demographic parameters appear to vary more between populations than they do as a result of the length of the inter‐fire intervals, and the specific demographic model discussed here may have only local application.
Short review of selected fish biomarkers of xenobiotic exposure with an example using fish hepatic mixed‐function oxidase
Authors: HOLDWAY D. A. , BRENNAN S. E. , AHOKAS J. T.
Published: July 2006

Abstract
One group of biological tools that are useful for monitoring exposure to xenobiotics (and hence water quality) have been collectively referred to as biomarkers and are denned in this paper as any biochemical, histological and/or physiological alterations or manifestations of stress. Biomarkers within an aquatic toxicological context generally represent biological responses of individual organisms to xenobiotic exposure (i. e. responses at the whole organism level of biological organization). These include among others, enzyme alterations, bile metabolites, RNA/DNA ratio, adenylate energy charge, skeletal abnormalities, immune dysfunction, behavioural changes and histopathological lesions. Biomarkers can act as effective early warning sentinels to ensure the protection of the integrity of whole ecosystems, including freshwater and marine ecosystems.

This paper briefly reviews a selection of fish biomarkers of xenobiotic chemical exposure and discusses their respective strengths and limitations for use in biomonitoring. An example of the application of fish mixed‐function oxidase (MFO) and cytochrome P‐450 as biomarkers of chemical exposure in Port Phillip Bay is provided. It is concluded that judicious application of biomarkers such as MFO in association with an understanding of the underlying causal mechanisms of induction and toxicity, will contribute to the successful prediction of biological effects of xenobiotic exposure on fish population health.
The use of fish in ecological assessments
Authors: HARRIS JOHN H.
Published: July 2006

Abstract
Fish provide powerful tools for assessing aquatic environments. Three attributes are especially significant: the sensitivity of fish to most forms of human disturbance, their usefulness at all levels of biological organization and the favourable benefit‐to‐cost ratio offish assessment programmes. Fish can be used as indicators over wide temporal and spatial ranges. Because they cover all trophic levels of consumer ecology, fish can effectively integrate the whole range of ecological processes in waterways. Fish have been used in many different roles for assessing river health and monitoring responses to remedial management. Three of these applications appear to have particular value for management of Australian rivers: (i) automated systems monitoring fish ventilation can provide sensitive, broad‐spectrum and continuous sensing of water quality to protect receiving waters or water‐supply intakes; (ii) programmes collecting routine data on commercial or recreational fisheries can be designed and analysed so as to isolate confounding effects due to fishery‐specific factors and, hence, used to detect and monitor environmental change on large scales; (iii) the Index of Biotic Integrity (IBI) can be modified to suit Australian conditions and fish communities to meet the important need for a predictive model of aquatic environmental quality. The IBI is a quantitative biological tool with a strong ecological foundation that integrates attributes from several levels of ecosystem organization. Examples of the use of IBI elsewhere suggest its robustness, flexibility and sensitivity can cope effectively with the low diversity of the Australian fish fauna and the dominance of ecological generalists. A provisional structure is suggested for a test of the IBI in four riverine regions of New South Wales.
Development and use of a system for predicting the macroinvertebrate fauna in flowing waters
Authors: WRIGHT JOHN F.
Published: July 2006

Abstract
River InVertebrate Prediction And Classification System (rivpacs) is a software package developed by the Institute of Freshwater Ecology (IFE) for assessing the biological quality of rivers in the United Kingdom. The system can be used to generate site‐specific predictions of the macroinvertebrate fauna to be expected in the absence of major environmental stress. Each prediction is based on a small number of environmental features that are used to characterize the site. The fauna predicted can then be compared with the fauna observed at the same site. This offers a procedure for evaluating biological quality with application in river management both at the local level and for national surveys. Close collaboration between the IFE team and biologists in the water industry during the project had a beneficial influence on the operational development of the system.

A second feature of RIVPACS is the national classification of sites, based on the macro‐invertebrate fauna. Although the classification is currently a pre‐requisite for the prediction system, it also has intrinsic value because newly sampled sites of high biological quality can be placed within the national framework, based on their macroinvertebrate fauna. This facility is of interest to the statutory nature conservation bodies as an element in their site appraisal procedures.

The predictive component of the current version of the system (RIVPACS n) was used in the 1990 River Quality Survey to assess the biological quality of almost 9000 sites throughout the United Kingdom. Further developmental work is now under way to provide a more comprehensive version of the system for the 1995 survey.
Factors contributing to the loss of seed from the seed‐bank of Trifolium balansae and Trifolium resupinatum over summer
Authors: JANSEN P. I. , ISON R. L.
Published: July 2006

Abstract
The influence of predation, fungi and germination of seed of the annual legumes Trifolium balansae and Trifolium resupinatum was investigated by placing known quantities of seed in bags in the field; combinations of all three factors were imposed. It was found that rainfall was the most important factor contributing to the loss of seed over summer (up to 76%), followed by predation (up to 15%); fungi had only a very small influence (0.1–0.2%). Predation contributed to a larger percentage of loss over summer in T. resupinatum line SA14433 than in T. balansae cv. Paradana, which is attributed to seed size. The effect of summer grazing on the size of the seed‐bank was investigated. It was found that summer grazing did not influence the amount of seed present in the seed‐bank in March. Removal of all surface material in December resulted in a significant drop in seed reserves compared with the ungrazed or grazed areas. Hardseededness in March was not affected by any of the treatments; the seedling density after regeneration was not affected by summer grazing, but was reduced when all surface material was removed. The data were incorporated in a model to describe seed loss from the seed bank over summer quantitatively; the utility of such models is discussed.
Regional and local variation in insect herbivory, vegetation and soils of eucalypt associations in contrasted landscape positions along a climatic gradient
Authors: LANDSBERG J. , GILLIESON D. S.
Published: July 2006

Abstract
Relationships with climate and local resources are developed for soils, vegetation and tree foliage as well as levels of herbivory for the dominant eucalypts at sites representing a regional gradient in climate and local contrasts in landscape position. Indicators of site productivity such as soil nitrogen and phosphorus, canopy height and cover, foliar nitrogen and water, and average leaf area tended to increase as climate became more favourable. Many were also higher in locally richer parts of the landscape. In contrast, specific leaf weight, an indication of sclerophylly, decreased as climate and local resources became more favourable. Rates of herbivory tended to increase with increasing site productivity and the associated changes in soil, vegetation and foliar properties, in broad agreement with models relating herbivory to resource availability and plant vigour. We found no evidence to support models relating high herbivory to low‐resource environments and plant stress. The apparent level of herbivore damage on mature leaves was highest at intermediate levels of resources; this could reflect interactions between resource availability, rates of herbivory and rates of leaf replacement. Implications of these findings are discussed with respect to ways of measuring herbivory, regional patterns in rates and levels of herbivory, and the regional distribution of rural dieback associated with high herbivory.
Impact of commercial forest management on geophilous carabid beetles (Coleoptera: Carabidae) in tall, wet Eucalyptus obliqua forest in southern Tasmania
Authors: MICHAELS K. F. , McQUILLAN P. B.
Published: July 2006

Abstract
The impact of silvicultural practices (clearfelling, slash burning and sowing) on carabid beetle communities in tall wet Eucalyptus obliqua forests in southern Tasmania was examined using traplines of pitfalls in a chronosequence of regenerating coupes. Total species richness (n= 18) was modest compared to other temperate forests and was not systematically changed by forest management, although it was considerably lower in 20 year old regrowth than in younger regrowth or old‐growth controls, possibly due to habitat simplification. The Shannon‐Weiner Index was at a minimum in intermediate aged regeneration. TWINSPAN analysis assisted recognition of beetle communities typical of broad stages in the forest succession, with a major dichotomy between most old‐growth sites plus young sites and intermediate plus advanced regeneration sites. Vector fitting of environmental variables in an ordination of the sites by non‐metric multidimensional scaling revealed a significant influence for the age of regeneration and litter depth, but not bare ground percentage or soil pH. Survival of carabids in the habitat mosaic created by commercial forestry activity is likely to depend on both reinvasion from edges and survival of individuals in the fire‐protected refuges that exist within the coupes. Pioneer species were winged, small in size, and non‐endemic whereas the opposite was true of the fauna in the older sites. Carabids in eucalypt forests have good potential as indicators but their seasonality in occurrence demands that sampling be extended over most of the year.
A comparison of foliar nutrient concentration in trees from monsoon rainforest and savanna in northern Australia
Authors: FENSHAM R. J. , BOWMAN D. M. J. S.
Published: July 2006

Abstract
Analysis of foliar nutrient concentrations revealed that two mesophyllic monsoon rainforest trees had higher concentrations of most nutrients in leaves than eight savanna species. One of the tested monsoon rainforest species with sclerophyllous leaves had similar nutrient concentrations to the savanna tree species. There were positive or no significant correlations between live foliar nutrient concentration and the percentage of nutrients withdrawn prior to litterfall. The nutrient concentration of litter was similar for most nutrients among tree species of monsoon rainforest or savanna. The results of this study suggest that the relative fertility of surface soils of monsoon rainforest compared with savanna is not determined by contrasting nutrient cycling strategies whereby monsoon rainforest tree species enrich their soils with relatively nutrient rich leaf litter relative to savanna tree species.
A protocol for classifying regional dynamics, exemplified by using woodland birds in southeastern Australia
Authors: MACNALLY RALPH C.
Published: July 2006

Abstract
Communities of forest and woodland birds are usually studied intensively at only one or a few locations. This provides a perspective that perhaps emphasizes local phenomena at the expense of placing local dynamics in the context of processes operating at the landscape or regional scale. The present paper seeks to redress partially this imbalance by studying the dynamics of individual bird species among several habitat types (all Eucalyptus‐dominated forests or woodlands) over the annual cycle. This regional‐scale (250km), continental study reveals that species exhibit idiosyncratic dynamics of various kinds: restricted or more ubiquitous occupation of habitats and three forms of seasonal dynamics at the regional scale (resident, migrant and itinerant). By using this classificatory scheme, it becomes evident that the bird communities found in different habitats consist of diverse collections of strategists and that the level of diversity differs among habitat types. The difficulties that many field workers have had in reconciling their observations with community theory most likely reflect the underlying dynamism of bird communities, especially in the temperate regions on continents where seasonal fluxes are pronounced.
Analysis of the spatial pattern of arthropod fauna of jarrah (Eucalyptus marginata) foliage using a Mantel correlogram
Authors: Burgman M. A. , Williams M. R.
Published: July 2006

Abstract
The results of a two year study of foliage arthropods in Eucalyptus marginata canopies by Abbott et al. led them to conclude that distance was unimportant in explaining the similarity of foliage arthropod faunas. However, that conclusion was based on an analysis that did not account for the lack of independence between sample points. Re‐analysis of their data using a Mantel correlogram detected significant spatial pattern in resemblance between canopy faunas, consistent with a patch size of about 20km.
Levels of understanding in ecology: interspecific competition and community ecology
Authors: Walter G. H. , Paterson H. E. H.
Published: July 2006

Abstract
Ecological interpretation has been subject to several divisive controversies, involving, for example, the significance of density dependence and interspecific competition as ecological processes. Generally, resolution has been obtained through compromise and concensus or calls for yet more data. Essentially, both sides in the discussion are seen to have been correct to some extent. As a consequence the debates have been portrayed widely as having been sterile. We agree, but only because they have been conducted at a level so superficial that the relevance of the original criticisms to the theoretical structure of ecology has not been widely appreciated, nor resolved. Debate that deals with ecological generalizations must be conducted at a level appropriate to such aims.
Roost selection by the north Queensland long‐eared bat Nyctophilus bifax in littoral rainforest in the Iluka World Heritage Area, New South Wales
Authors: LUNNEY DANIEL , BARKER JOHN , LEARY TANYA , PRIDDEL DAVID , WHEELER ROBERT , O'CONNOR PAUL , LAW BRADLEY
Published: July 2006

Abstract
The aim of this study was to describe the roosts of Nyctophilus bifax in littoral rainforest in Iluka Nature Reserve on the north coast of New South Wales. Radio‐telemetry was used to track 17 bats in November 1988 (lactation season) and 11 in May 1989 (mating season) to 87 roosts in 49 trees within the littoral rainforest. The bats frequently changed roosts, which were clustered within a small area. During November, lactating females moved twins between diurnal roosts and some carried twins while foraging. Twins represented a load of up to 95% of their mother's bodyweight. Bats roosted communally in foliage and tree hollows, beneath peeling bark, among epiphytes, and between strangler figs and host trees. Hollows were used more frequently when bats were lactating, while the use of foliage roosts was greater during the mating season. Roosts were concentrated in four tree species, although a wide range of other tree species was used. Roost trees used in November were taller (17m) than those used in May (8. 2 m), and reflect selection of Syzygium leuhmannii and Acmena hemilampra, both trees of the forest interior. The converse applied for selection of Cupaniopsis anacardioides, a small tree of the littoral zone, in May. These results identify the need for conserving a diversity of roosts for this species of bat.
The size, distribution and germination requirements of the soil‐stored seed‐bank of Grevillea barklyana (Proteaceae)
Authors: EDWARDS WILL , WHELAN ROB
Published: July 2006

Abstract
Fire‐triggered release from seed dormancy is a characteristic of many Australian plant species. We investigated aspects of the seed‐bank dynamics and dormancy characteristics in seeds of Grevillea barklyana, an understorey shrub of coastal sclerophyll vegetation in the Jervis Bay Region on the south coast of New South Wales. We used two soil core sizes to compare the number and distribution of stored seeds in soil cores taken from underneath and outside the limits of plant canopies at three study sites. Core size did not affect the estimate of seed density. No seeds were found outside the existing canopies. Even in under‐canopy samples, seed numbers were small. Mean seed densities were estimated as 10. 9, 14. 1 and 4. 3 seeds per for the three sites. A hierarchical series of laboratory experiments was used to test the germination response of both fresh and soil‐stored seeds. Likewise, we attempted to simulate ‘natural’ disturbance conditions in a glasshouse experiment. Both laboratory and glasshouse experiments indicated polymorphism in germination behaviour. A constant proportion of seeds exhibited enforced dormancy, when moist at room temperature, while a smaller number of seeds showed either an induced dormancy or a non‐seed‐coat linked innate dormancy. The majority (75%) of seeds were innately dormant due to a hard seed‐coat. This dormancy was broken when the seed‐coat was damaged, for instance, by heat. The level of polymorphic germination behaviour will be dependent on the length of the inter‐fire periods. We conclude that the expression of polymorphism within and between species across a range of environments and fire regimes is an important consideration for any further study attempting to assess the role of the seed‐bank.
Habitat alteration, hunting and the conservation of folivorous primates in African forests
Authors: GATES JOHN F.
Published: July 2006

Abstract
The colobus monkeys and gorillas of African forests share a strong tendency to depend on foliage during lean seasons. In many areas, both kinds of primate are threatened by habitat destruction. But while the total removal of natural habitat is clearly a major threat to the survival of many African forest primates, an analysis of survey data suggests that human predation tends to have a greater negative impact on primate populations than does selective logging or low‐intensity bush‐fallow agriculture. In the absence of hunting, the population density of colobus monkeys correlates with the protein: fibre ratio of mature tree foliage in their habitat, and the density of gorillas appears to be correlated with the abundance of terrestrial herbaceous vegetation. Because moderately disturbed forest can be relatively rich in high‐quality lean‐season folivore foods, such forest sometimes supports a higher density of folivorous primates than forest that has not been recently disturbed but that has been subject to hunting. Conservation plans for African forests should place more emphasis on the control of hunting and less on rural development, and long‐range plans should also allow for the strong possibility of political instability.
Conservation of arboreal herbivores: The Australian scene
Authors: BRAITHWAITE L. W.
Published: July 2006

Abstract
A common global issue in biological conservation, that of land use allocation and subsequent management practice, is also at the core of the problem of conserving arboreal herbivores in Australia. The problem is caused by a number of biological and cultural factors. Many populations of Australia's terrestrial vertebrate fauna species of forest and woodland environments, including notably the arboreal herbivores, are concentrated in habitats on soils relatively rich in nutrients. Such habitats are limited due to (i) Australia's general aridity and its naturally poor endowment of soils of reasonable quality, and (ii) the extent to which habitats on the better soils have been cleared to service Australia's social and economic development. Land clearing has focused on these better soils because of cultural traditions in agriculture, and society's recognition of the importance of ‘good’ soils to a nation's development. As a result, Australia has legislation and numerous government policies and programmes that aim to identify and make maximum use of the productive potential of Australia's land. For example, the Crown Lands Alienation Act of 1861 was enacted expressly to transfer land from public to private or leasehold tenure and to develop those lands best suited for agriculture and pastoralism. As a result, from 1861 to the end of the nineteenth century, large areas were extensively cleared and potentially commercial forests were destroyed. The remaining uncleared land in private tenure today carries a major part of the woodland and forest resource on the better soils. Woodland and forest associations on these soils are generally poorly represented in reserves. Furthermore, the Australian constitution, and laws concerning the rights of the private landholder and the use of forest resources on leasehold land, indirectly or implicitly encourage or otherwise act to minimize the constraints on continued land clearing.

From the above facts and because human populations are expected to increase, the prognosis for Australia's woodland and forest fauna, including the arboreal herbivores, is one of ongoing loss of important habitats. This paper suggests the following measures for ameliorating this loss: identify strategically important habitats, and encourage private philanthropic purchase or government purchase of timber rights, or subsidize the management of these habitats; examine possible trade‐offs in public expenditures on forest administration and management in return for public purchase of privately held forests; establish educational programmes that encourage a conservation ethic and a better community understanding of the realities and the extent of the difficulties to be addressed.
Seasonality of canopy invertebrate communities in eucalypt forests of eastern and western Australia
Authors: RECHER H. F. , MAJER J. D. , GANESH S.
Published: July 2006

Abstract
Chemical knockdown procedures were used to sample canopy arthropods at 3 month intervals over 1 year at two sites, one in eastern Australia and the other in western Australia. Samples were taken from narrow‐leaved ironbark, Eucalyptus crebra, and grey box, Eucalyptus moluccana, in the east and from jarrah, Eucalyptus marginata, and marri, Eucalyptus calophylla, in the west. Arthropods were more abundant on trees in eastern Australia and exhibited different seasonal patterns from those in the west. Members of different functional groups exhibited different seasonal patterns, with some herbivorous groups responding to times of leaf production, decomposers and fungus feeders responding to high moisture availability, and predators/parasites responding to the abundance of food items. Seasonal variability was slightly higher in the west, possibly reflecting the greater seasonal amplitude in rainfall. In the eastern forest, proportionately more taxa peaked in spring or summer and declined to minimum numbers in winter. In the western forest several taxa attained peak numbers in autumn, winter or spring, while others declined to minimum values in winter or summer. The phenological patterns of canopy arthropods appear to be linked to the condition of the host plant and/or to climatic factors. Comparison of the western Australian data to those from a second year of sampling at a time when rainfall was greater and fell later into the season indicated that variability in arthropod numbers between years can be as great as that between seasons. Implications of the variability in seasonal and annual patterns of canopy invertebrate communities are discussed in relation to the need for long‐term sampling and in relation to evaluating the impact of disturbance on forest communities.
Soil temperatures after the passage of a fire: Do they influence the germination of buried seeds?
Authors: Auld Tony D. , Bradstock Ross A.
Published: July 2006

Abstract
Soil temperatures down to a depth of 5 cm were measured in the days following one fire in summer, one fire in winter and in unburnt vegetation during summer. Soil temperatures did not rise above 40°C after the winter fire or in unburnt vegetation during summer. Consequently, no impact on seed dormancy in the soil seedbank was expected. After a summer fire, soil temperatures above 40°C were found up to 4.5 cm in depth, while temperatures above 60°C were found only in the top 0.5 cm of soil. These temperatures are sufficient to break seed dormancy in some legume species in the seedbank. Hence, the season of burn may influence the number of seeds in the soil that have their dormancy broken and subsequent germination levels.
Effects of a predatory fish (Galaxias olidus) on the structure of intermittent stream pool communities in southeast Australia
Authors: GLOSS GERARD P.
Published: July 2006

Abstract
The impact of predation over a 3 week period by the small (mean length 53 mm) salmoniform fish, Galaxias olidus, on the invertebrate communities in the still summer pools of an intermittent stream in southeastern Australia was tested using enclosures that incorporated both deep and shallow habitat areas. Twenty G. olidus, a key generalist predator in the system studied, were enclosed for 3 weeks in 1.5 × 1.7 m enclosures. Galaxias olidus was found to reduce significantly the distribution and abundance of air‐breathing nektonic species. In contrast, the abundance of non‐air‐breathing nektonic species increased in the presence of fish in the deep areas of the enclosures. There was no significant impact offish predation on species richness, total abundance, epibenthic or interstitial species. The most likely reason for the general lack of response to the presence of fish by epibenthic and interstitial species is the availability of abundant spatial refugia from predation within the complex substrate of the stream. In contrast, air‐breathing nektonic species are vulnerable to predation by fish due to the lack of refuges in the open water. Increases in the abundance of non‐air‐breathing nektonic species in the presence of fish may be related to reductions in the abundance of predatory dytiscid beetles. Significant differences between deep and shallow habitats were observed in total abundance and species richness, and in the abundances of air‐breathing nektonic and epibenthic species, suggesting that physicochemical factors play a key role in determining invertebrate distribution within stream pools.
Microhabitat choice and its role in determining the distribution of the reptile tick Amblyomma vikirri
Authors: DUFFIELD G. A. , BULL C. M.
Published: July 2006

Abstract
A newly described tick species, Amblyomma vikirri, infests two lizard species in the Flinders Ranges of South Australia. Although one of the hosts, Tiliqua rugosa, has a wide distribution, the tick distribution is restricted to a subset of rocky habitats where the other host, Egernia stokesii, lives. Experiments were conducted with unfed ticks, the stage when the tick is waiting for a host and is susceptible to desiccation. Amblyomma vikirri had a significantly stronger preference for rock microhabitats than two other tick species (Aponomma hydrosauri and Amblyomma limbatum) that infest T. rugosa. Unfed Amb. vikirri were also more active than the other two species, and more likely to be in the upper pan of the substrate. At warm temperatures, larvae of Amb. vikirri survived for shorter periods under desiccation stress than larvae of the other two species, although as nymphs Amb. vikirri survived as well or better. The rock crevice microhabitat experienced lower maximum temperatures than other potential, non‐rock refuge sites. The behaviour of Amb. vikirri, its susceptibility to desiccation in the larval stage and the relatively benign conditions in the rock crevices may act together to prevent Amb. vikirri establishing populations beyond rock habitat.
Nesting activity, breeding success and colony size for the Wedge‐tailed Shearwater Puffinus pacificus on Heron Island
Authors: HILL GREG J. E. , DYER PAM K. , CARTER JENNY L. , BARNES TONY
Published: July 2006

Abstract
The Capricorn Group of islands in Australia's Great Barrier Reef Marine Park sustains one of the world's largest breeding populations of the Wedge‐tailed Shearwater Puffinus pacificus. Heron Island, a 13.5 ha coral cay which supports tourist and research station leases as well as a national park, is the third largest nesting island in the group. Sample censuses of breeding burrows were conducted each year between 1985 and 1990 and a further survey was completed in 1993. These returned estimates of between 13 264±1387 and 16 337±1545 active burrows (Y±SE). Burrow densities within each of the habitats monitored showed no significant trends between years, although there were large differences in burrow density between habitats. There were roughly the same number of burrows in the developed (west) and national park (east) halves of the cay. A miniature video camera system (burrowscope), which allowed nesting chambers at the ends of burrows to be inspected, was used in 1989, 1990 and 1993. This demonstrated that around half the burrows were occupied by incubating birds. Variations were found in the distribution of incubating birds between habitats, although this did not remain constant between the years. In the 1993 season, breeding activity was traced from the burrow establishment to fledging stage. Fifty‐one per cent of burrows were used for breeding (eggs laid), 77% of eggs hatched and 80% of chicks produced a fledgling. Overall breeding success for the island was estimated at 61%. In 1993 the area designated as Buildings was found to have significantly lower hatching success compared with natural habitats. Most mortality occurred at the egg stage; however, in the Fringe habitat, mortality was highest at the chick stage. Previous surveys have estimated the breeding population from burrow counts. It now appears that only about 30% of such burrows produce fledglings.
Seed production, dispersal and germination in Cryptostegia grandiflora and Ziziphus mauritiana, two invasive shrubs in tropical woodlands of northern Australia
Authors: GRICE A. C.
Published: July 2006

Abstract
Cryptostegia grandiflora and Ziziphus mauritiana are exotic shrubs that are invading tropical woodlands of northern Australia. Although they are widespread, they currently occupy only small proportions of their respective potential ranges. Large C. grandiflora can produce more than 8000 wind‐dispersed seeds in a single reproductive episode and can set seed at least twice per year. More than 90% of seeds will germinate within 10 days of moisture becoming available. Few, if any, seeds survive for more than 12 months in the soil. Large Z. mauritiana can produce more than 5000 fruits per year. The fruit is a drupe that contains a single seed (sometimes two) enclosed in a woody endocarp. Less than 10% of fresh seeds will germinate without removal of the endocarp. Removal of the endocarp increased germination to 56%. Less than 10% of seeds of Z. mauritiana remain viable after burial in the soil for 12 months. Seeds of Z. mauritiana are dispersed by several mammalian vectors, including wallabies and feral pigs, but domestic cattle are probably the major means by which large numbers of seeds reach new sites. Propagules pass intact through the digestive tract of cattle, feral pigs and wallabies and contain viable seeds that germinate more readily than seed in fresh intact fruits. Controlling movement of cattle that have had recent access to mature fruit of Z. mauritiana could significantly reduce the likelihood of new infestations. For both species, management that reduces seed production will be important for containing spread.
Decreased food intake in reproducing lizards: A fecundity‐dependent cost of reproduction?
Authors: SCHWARZKOPF LIN
Published: July 2006

Abstract
Reproduction has been shown to be costly in viviparous skinks, both in terms of survival and in terms of growth and future reproductive output. One possible source of such costs could be a reduction in food intake, with an associated reduction in energy available for maintenance and future reproduction. Therefore, I compared food intake in male and female southern water skinks (Eulamprus tympanum), to determine whether food intake was reduced during reproduction in either sex. In addition, I measured the relationship between reduction in food intake and the total volume of offspring or testis. A reduction in food intake proportional to the volume of offspring suggests that costs associated with reduced energy intake may be fecundity dependent. Food intake was estimated using the total volume of stomach contents of individuals. Females ate significantly less (mean volume of stomach contents = 0.13mL) than males (mean = 0.36mL) just before parturition in January, when embryos were largest. After parturition, females ate significantly more than males. Otherwise, there were no significant differences between the food intake of males and females. Females reduced food intake by eating smaller food items. Females with relatively large numbers of ova or embryos ate relatively less, and therefore decreased food intake in females may be a fecundity‐dependent cost of reproduction in these lizards. Males did not reduce food intake during periods when testes were enlarged and mating occurred. Decreased food intake during reproduction is probably an important source of reproductive costs to females of these viviparous lizards, but does not appear to be important in males.
Can predators maintain parapatry? Ant distribution across a tick parapatric boundary in South Australia
Authors: CHILTON NEIL B. , BULL C. MICHAEL
Published: July 2006

Abstract
Ants were sampled by pitfall traps at 85 sites, 0.5 or 1.0km apart, along six transects across a parapatric boundary between the reptile ticks Aponomma hydrosauri and Amblyomma limbatum near Mt Mary in South Australia. There was no tendency for overall ant density, or for the distribution of any single species of ant, to be related to the tick distribution. Thus the survey found no support for the hypothesis that predation by ants was maintaining the boundary. Along transects there were no correlations between ant and tick densities. Thus the survey found no support for the hypothesis that ant predation was a major factor controlling tick densities. These negative results provide further evidence that single, strong ecological processes cannot explain this well‐studied parapatric boundary.
Light requirements for regeneration in tropical forest plants: Taxon‐level and ecological attribute effects
Authors: OSUNKOYA OLUSEGUN O.
Published: July 2006

AbstractUnderstanding co‐adapted traits and strategies in organisms has been increasingly shown to require a broader view of structure, function, taxonomic affiliation (phylogeny) and their possible interactions. In order to understand mechanisms of recruitment dynamics in tropical forest, nine juvenile (fruit, seed and seedling) and seven adult ecological and morphological traits were examined in 89 woody plant species, from 75 genera, 35 families and 21 orders. The species were from tropical rainforest in northern Queensland and varied widely in light requirements and hence regeneration niches. The importance of taxonomic (phylogenetic) constraints was considered using various techniques. Data were collected mostly from herbarium specimens, augmented by observations in the field. The main source of variation in most traits was at the species level, although fruit size and light requirement varied most at the genus level, and flower size at the level of order. Covariation among attributes increased in strength with increasing taxonomic level. Cluster analyses of the species arising either from five or three groups reflected juvenile rather than adult attributes. However, these groups were not morphologically distinct. Sets of juvenile traits poorly predict adult functions (and vice‐versa) at species, genus and family levels, but do so more strongly at the order level. Analyses of variance and multivariate analyses, with and without the effects of phylogeny, indicated that fruit size, seed size, hardness of seed coat, seedling cotyledon function, fruit maturation period and, to a lesser extent, seed number per fruit and wood density could predict light requirement, and hence regeneration niche. Flower size showed a strong phylogenetic effect, and thus is conserved along taxonomic lines. It is concluded that as different traits may vary at different taxonomic levels, the influence of phylogeny on interspecific variation needs to be routinely recognized by ecologists involved in comparative analyses of plant life‐history functions.
Ant‐ and termite‐eating in Australian mammals and lizards: a comparison
Authors: ABENSPERG‐TRAUN MAX , STEVEN DION
Published: July 2006

Abstract
Relative abundance is one factor that influences selection of prey by insectivorous mammals and lizards. Ants and termites are extremely abundant over most of inland Australia. Their patterns of abundance are also broadly similar across climatic gradients, being most and least abundant in seasonally arid (tropic and sub‐tropic) and temperate mesic regions, respectively. All else being equal (e. g. mechanisms of prey defence, palat‐ability, availability), animals that eat many termites should also eat many (adult) ants. The present study asks three questions: (i) What is the diversity of specialized ant‐eaters (>50% volume)?; (ii) Does specialization vary with climate?; and (iii) Are ants and termites eaten in broadly similar proportions (using an earlier study on termites).

Of the mammals, only the echidna (Tachyglossus aculeatus) in mesic regions, and probably the marsupial mole (Notoryctes typhlops) in the arid zone and the striped possum (Dactylopsila trivirgata) in mesic regions are ant‐specialized. Ant‐specialization in mammals shows no pattern with regard to climate. Of the lizards, only four agamid lizards are ant‐specialized: Moloch horridus (arid, semi‐arid), Ctenophorus fordi (arid, semi‐arid), Ctenophorus isolepis (arid) and Ctenophorus maculatus (arid). Specialization on ants by lizards is greatest in the arid zone (4 spp.); no lizard species were found to be ant‐specialists in mesic regions.

In the arid and semi‐arid zone, two mammals each specialize on termites and one on ants; in mesic regions, two mammals specialize on ants and one on termites. Specialized insectivorous mammals thus demonstrate no marked preference for either termites or ants. Lizards, in contrast, are markedly termite‐specialized (4 ant‐specialist spp., 16 termite‐specialist spp.), and specialization is greatest in the arid zone (16 spp.). Greater specialization on termites than on (adult) ants in lizards is explained with reference to differences in prey defence and palatability between ants and termites. Consumption of ant brood (eggs, larvae, pupae) appears to be associated with a fossorial foraging mode (the marsupial mole N. typhlops; spp. of Aprasia lizards; spp. of blindsnakes Ramphotyphlops).
Habitat use by sympatric populations of Pseudomys novaehollandiae and Mus domesticus in coastal heathland
Authors: HAERING RON , FOX BARRY J.
Published: July 2006

Abstract
Patterns of habitat use by Pseudomys novaehollandiae and Mus domesticus were investigated on a 6. 8 ha area of coastal heathland, almost five years after it last burned in Myall Lakes National Park. One hundred and fifty‐one trap stations were positioned on 17 traplines across a mosaic of interlocking macrohabitats. This pattern was a consequence of the site's topography and to a lesser extent fire history. Multivariate statistical procedures were employed to identify those microhabitat parameters that contribute to both individual species’ habitat use and the partitioning of habitat to reduce competition for space. Trapping results show P. novaehollandiae to be almost three times as abundant as M. domesticus at this time, although M. domesticus does show strong regional, and hence local, fluctuations in abundance over time. Both species exhibit habitat selection (P< 0. 05) with individuals preferring dry, tall closed heath and open heathland habitats. Immature P. novaehollandiae (< 15 g) were found mostly in short dense wet heath and may have been dispersing. Species exhibit high between‐habitat overlap using Pianka's formula (0. 88). This overlap is substantially reduced within macrohabitats (0. 28), when trap stations are considered as resource states, suggesting a considerable degree of microhabitat separation at the trap station level. Discriminant function and multiple regression analyses identify microhabitat selection that is not strongly focused, suggesting both species to be spatial generalists. Elevation was selected as the most significant variable in these analyses and represents a soil moisture gradient that determines changes in the floristic and structural components of the biotic environment. No single habitat variable was found to explain within‐habitat separation convincingly, however, when a factor analysis of habitat variables was used to produce a reduced three‐dimensional factor space the outcome was marked. The 95% confidence envelopes for the distribution of each species show an extremely low overlap in factor space, with a zero overlap in the X‐Y plane and less than 1% overlap in theY‐Z plane. Differential micro‐habitat selection does produce effective habitat partitioning, thus facilitating coexistence of these two species. We suspect this occurs primarily by M. domesticus altering habitat selection. There is evidence to suggest that M. domesticus acts as a fugitive species occupying resource niches left vacant by P. novaehollandiae and other small mammal species coexisting on the study area.
The relative shade‐tolerance of Atherosperma moschatum and Elaeocarpus holopetalus
Authors: OLESEN T.
Published: July 2006

Abstract
Atherosperma moschatum had higher dry weight specific maximum leaf carbon exchange rates (CER) than Elaeocarpus holopetalus, which were achieved at lower photosyn‐thetic photon fluence rates (PPFR). A. moschatum also had higher dry weight specific leaf chlorophyll concentrations and initial slopes to the CER‐PPFR plots. The results are consistent with the superior shade‐tolerance of A. moschatum over E. holopetalus. The current co‐dominance by A. moschatum and E. holopetalus of rainforests on the Errinundra Plateau seems to be related to the openness of die canopy.
Bryophyte and lichen diversity: A comparative study
Authors: PHARO EMMA J. , BEATTIE ANDREW J.
Published: July 2006

AbstractWe describe the regional species richness, variation in species richness and species turnover of bryophytes and lichens from 36 sites in lowland forests of southeastern Australia. The analyses subdivided the two major taxa into their constituent sub‐groups: mosses, liverworts, and crustose, fruticose and foliose lichens. They also explored correlations between selected environmental variables and patterns of diversity. On a regional scale, there were 77 species of bryophytes and 69 species of lichens, giving a total of approximately one‐third of the total number of vascular plant species in the region. Mean species richness was higher for lichens than bryophytes. Also, the two taxa were negatively correlated because lichens favoured dry sites and bryophytes favoured moist ones. Species turnover was greater for bryophytes than lichens, largely due to the distribution of liverwort species. Foliose lichens showed higher levels of turnover than crustose lichens. Multiple regression and canonical correspondence analysis showed that both taxa and all sub‐groups responded to the same three variables: vascular plant cover, time since last fire and topographic position. Other variables, including time since logging and intensity of logging, explained little variation in bryophyte or lichen diversity. The data suggest that the strategies for the conservation of bryophyte and lichen biodiversity will be different, to reflect the different patterns of species richness and species turnover.
Local environmental correlates of variability in the organic soils of moorland and alpine vegetation, Mt Sprent, Tasmania
Authors: BRIDLE K. L. , KIRKPATRICK J. B.
Published: July 2006

Abstract
Data on soils, vegetation and environment were collected between 510 and 1050m a. s. l. on Mt Sprent, southwestern Tasmania, traversing the Gymnoschoenus sphaerocephalus sedgeland‐alpine vegetation boundary. One or more of the following horizons were found in almost all soil pits (downwards from the surface to the bed rock) fibric peat, hemic peat, sapric peat, organic sand, sand and clay. Mean total soil depth, mean organic soil depth, mean humification of the soil surface horizon, pH and mean organic content of the surface horizon all decline with altitude, while the redness of the soil and the mean depth of the mineral and gravel layers increase. At four intensively studied sites at 620, 850, 930 and 1040 m the relationships between phytosociological, topographic and water‐table variables, and soil characteristics were determined. The pH of the topsoil was significantly positively related to water‐table depth at three sites, but there were no other relationships between local environmental variation and soil characteristics that were consistent between most of the four sites, despite a large number of locally significant relationships. The alpine and sedgeland soils differ most markedly in colour, number of horizons and degree of humification of the surface horizon. The vegetation at each site was separated into communities along a drainage gradient. The mesoscale differences in soils seem most likely to be attributable to a vegetation productivity gradient.
The interaction between the coastal brown ant, Pheidole megacephala (Fabricius), and other invertebrate fauna of Mt Coot‐tha (Brisbane, Australia)
Authors: HETERICK BRIAN
Published: July 2006

Abstract
Sampling of invertebrate fauna was carried out on Mt Coot‐tha, between 25 February and 11 March 1992, to determine whether the presence of the coastal brown ant, Pheidole megacephala (Fabricius), affected die abundance and diversity of other invertebrates. Four plots were sampled; in two the coastal brown ant was present and in two it was absent. The overall abundance of invertebrates did not differ significantly between plots. The abundance of Collembola did vary significantly, but intraplot variability was large. Mite numbers did not differ significantly between plots, except for the family Laelapidae. Abundance of other ant species did not differ significantly between plots, but there was a difference in species composition; Dolichoderinae and Ponerinae were absent or poorly represented in plots where the coastal brown ant was present.