bluuebunny/crossref_metadata_2025 huggingface dataset:
Arthropod fauna of jarrah (Eucalyptus marginata) foliage in Mediterranean forest of Western Australia: Spatial and temporal variation in abundance, biomass, guild structure and species composition
Authors: ABBOTT I. , Burbidge T. , WILLIAMS M. , Van Heurck P.
Published: July 2006

Abstract
A 2 year study (using a branch‐clipping technique) of the arthropod fauna of jarrah crowns (14 m above ground level) in a 7500km2 area centred on Manjimup, Western Australia, yielded 7461 individuals belonging to 396 species. Lepidoptera, Hemiptera and Araneae dominated the fauna in abundance and biomass but Lepidoptera less so in number of species. Consequently, leaf chewers, sapsuckers and predators were the dominant guilds. Most species showed great spatial and temporal variation in their occurrence, with some 73% being recorded on only one or two of the nine sampling occasions. In addition 77% of species were recorded on four or fewer of the 45 trees sampled. Crowns of these trees tended to have highly dissimilar assemblages of arthropods. Dissimilarity between trees was not predictable from the distance between them. Total species richness was greatest in samples collected in summer. Predators and sapsuckers tended to be the most speciose guilds. Within‐stand differences were much less pronounced than between‐stand differences: ants were more abundant on jarrah foliage within 2 m of ground level and the pest defoliator Uraba lugens (Lepidoptera, Noc‐tuidae) was more abundant on foliage of jarrah pole crowns 14 m above ground. The most abundant arthropod, U. lugens, did not reduce appreciably the biomass or abundance of other arthropod groups present in jarrah pole crowns. This is consistent with the paradigm that competition between species of herbivorous insects is infrequent. After comparison with other studies in jarrah forest, we tentatively conclude that there is no single fixed pattern of organization or predictable assemblage of invertebrates on jarrah foliage.
Application of repeated measures designs in environmental impact and monitoring studies
Authors: GREEN R. H.
Published: July 2006

Abstract
Traditional environmental studies have employed sampling at different times, but based on re‐randomized ‘replicate’ samples taken at each time. For example, in a 4 year monitoring study of near‐shore marine benthic communities there might be three box cores collected annually at each of three depths along each of three transects. Repeated measures designs, long used in medicine and the social sciences, are based on resampling replicates (e.g. sites) at a series of times. In such designs spatial sampling variability is not used for tests of environmental impact. Error for such tests is based on variability of time trends among similar sites (similar with respect to impact). For example in a tropical oil spill study five oiled and five unoiled coral reefs were studied over 5 years. Error for tests of oil impact was based on variability among reefs (within degree‐of‐oiling category) in the year‐to‐year trends of biological response variables. It was not based on variability among field samples within reefs at given times.

The two approaches (univariate and multivariate) to repeated measures analysis of variance are described. The pros and cons of each are discussed, as are the assumptions and consequences of their violations. Emphasis is especially placed on the adequacy of error degrees of freedom in the two approaches, and some exploration of power to detect impact is presented. Examples of application of repeated measures designs to various impact and monitoring studies are presented and discussed, including (i) interpretation of significant effects; (ii) decomposition of effects by contrasts (e.g. before vs after impact); and (iii) modelling time trends by polynomial and cosine functions.
The mechanics of spatially replicated sampling programmes to detect environmental impacts in a variable world
Authors: UNDERWOOD A. J.
Published: July 2006

Abstract
Procedures used to detect environmental impacts that occur as a result of planned disturbances are often inadequate. Widely used designs for univariate measures, such as the abundance of a population, lack proper spatial replication and have unjustified patterns of temporal sampling. Asymmetrical analyses of variance derived from repeated measures models can be used to detect many types of impact that are not identifiable using widely recommended BACI (Before/After, Control/Impact) sampling. These asymmetrical, beyond BACI designs are also more logical because of spatial replication. The mechanics of these procedures are discussed, including worked examples of calculations, considerations of their power to detect impacts of a specified magnitude and the integration of various temporal and spatial scales into the design. Related issues are briefly discussed concerning optimization of sampling and how to proceed when no data are available before a disturbance.
The ecological impact of Phytophthora cinnamomi in the Stirling Range National Park, Western Australia
Authors: WILLS R. T.
Published: July 2006

Abstract
An assessment of the impact of the soil‐borne pathogenic fungus, Phytophthora cinnamomi (Oomycetes, Peronosporales), on the plant communities of the Stirling Range National Park was carried out between December 1988 and April 1989. A total of 541 plant species were collected, with the Proteaceae and the Myrtaceae the two largest families in the study region. Of the 330 species assessed for susceptibility to P. cinnamomi, 118 (36%) were recorded as having at least some individuals in a population judged to have been killed by the fungus and 33 (10%) were highly sensitive to the pathogen (more than 80% of plants in a population killed). Several families had large numbers of susceptible species, while others were apparently unaffected by the pathogen. Notably, 85% of proteaceous species assessed were rated as susceptible to P. cinnamomi. Proteaceous elements had a mean projective foliage cover of 40% in healthy plant communities, but had a mean cover of only 10% at sites that had a long history of infestation with the fungus. In contrast, some species with low levels of susceptibility to the pathogen, such as some monocotyledons, were found to be more abundant at old‐infested sites than at healthy sites. Growth form may also influence susceptibility, with herbaceous perennials, annuals and geophytes assessed in this survey apparently unaffected by the fungus whereas 48% of woody perennials surveyed were susceptible.

Changes in the floristic structure of plant communities may influence the composition of associated animal communities. In particular, vertebrate flower visitors may be vulnerable since 59% of the species with vertebrate‐pollinated flowers were found to be susceptible to the pathogen. This research highlights the serious ecological impact of P. cinnamomi on native plant communities and suggests that significant components of the flora and associated fauna of the southwest of Western Australia are endangered by this virulent pathogen.
The intertidal distribution of the grey mangrove (Avicennia marina) in southeastern Australia: The effects of physical conditions, interspecific competition, and predation on propagule establishment and survival
Authors: CLARKE P. J. , MYERSCOUGH P. J.
Published: July 2006

Abstract
The upper and lower limits of the distribution of mature Avicennia marina lie between mean high water and mean sea level in open estuaries in southeastern Australia. Newly established seedlings are highly variable in abundance, but are rarely found in the saltmarsh or on mudflats. Their distribution is unlikely to be limited by dispersal because propagules disperse into the saltmarsh and to intertidal mudflats, but their establishment may be limited by physicochemical conditions, interspecific competition and predation.

The model that physicochemical conditions control the intertidal limits of establishment of seedlings was accepted for propagules stranding in the saltmarsh but rejected for those stranding on mudflats. No seedlings established on saltmarsh sediments but similar numbers of seedlings established within light gaps in adult mangrove stands and on intertidal mudflats. The model that interspecific interaction with freeliving macroalgae (Hormosira banksii) reduces the establishment of seedlings on mudflats covered with macroalgae or in stands with a ground cover of macroalgae was accepted. Under controlled conditions five times as many propagules established on cleared ground compared with ground covered with macroalgae. Predators also reduce seedling establishment, but the model that they preferentially act on propagules stranding on the mudflat was rejected. The low number of seedlings found on mudflats without macroalgae appears to relate to wave and current effects on establishment and the effects of waterlogging or fouling on survival.
A comparison of two methods for sampling assemblages of subterranean, wood‐eating termites (Isoptera)
Authors: ABENSPERG‐TRAUN MAX
Published: July 2006

Abstract
Within a 50 × 50 m area of wandoo Eucalyptus capillosa woodland in the Western Australian wheatbelt, the diversity and frequency of occurrence of wood‐eating termite species was assessed at two food types. Over a 12 month period, monthly termite activity was determined: (i) at sound/undecayed artificial baits (seasoned wooden stakes of Jarrah, Karri, Pine, Batu, Oregon; Jarrah sawdust; paper rolls); and (li) at naturally occurring timber, fallen logs and branches of wandoo, in varying stages of decay. Termite diversity was 11 species at baits, 18 species at wandoo out of an overall site richness of 21 species. Karri attracted the most species (9); sawdust attracted none. At wandoo, Nasutitermes exitiosus, Coptotermes acinaciformis and Occasitermes occasus accounted for 59% of samples where termites were recorded. At baits, Heterotermes occiduus accounted for a mean of 80% of samples across bait types, but was rarely sampled at wandoo (5% of samples). Only H. occiduus, C. acinaciformis and Amitermes neogermanus ate bait. Pine, Oregon and paper rolls were most effective in attracting foraging termites in terms of highest per cent of replicates showing bait consumption and highest consumption rates. Jarrah and Batu were least attractive to foraging termites. Samples from wandoo underestimated the relative frequency of occurrence of H. occiduus within the study site. Coptotermes acinaciformis, which attack large food items, and certain species of Amitermes, which forage on subterranean food, may have been underestimated by both sampling methods. These findings indicate that a proper understanding of the structure of wood‐eating termite assemblages within a given area requires a composite sampling strategy which addresses termites that eat sound or decayed wood, as well as surface and subsurface foragers.
Growth of seedlings of the invasives,Acacia salignaandAcacia cyclopsin relation to soil phosphorus
Authors: WITKOWSKI E. T. F.
Published: July 2006

AbstractAcacia salignaandAcacia cyclopsare the dominant invasive alien plants of phosphorus‐poor, sand‐plain, lowland fynbos and the relatively phosphorus‐rich strandveld vegetation of the southwestern Cape of South Africa, respectively, but their ranges overlap. Seedlings of the two species were grown in pots, in isolation and mixed, in up to seven treatments supplying a broad gradient in phosphorus (P) availability.Acacia salignaseedlings grew taller and had greater dry mass than those ofA. cyclopsat each level of P, but both peaked in response to the same relatively high soil P level and then tended to decline. Root : shoot ratios did not differ in response to P, but were greater inA. saligna. In mixture,A. salignahad a higher dry mass thanA. cyclopsat each level of P, but the relative differences between species were no greater than in isolation. Depth penetration of the soil by the tap root ofA. salignaseedlings was over three times as rapid as that ofA. cyclopsover a 30 day period. The higher absolute growth rates ofA. salignawere not related to seed size or seed nitrogen and P contents, as these were greater inA. cyclops. The contrasting distributions of the acacias do not appear to be a response to P availabilityper se, but possibly to the interaction of P with other factors such as moisture availability.
Simulation of bracken cover in forested areas in Victoria in response to season, overstorey and fire conditions
Authors: TOLHURST KEVIN G. , BURGMAN MARK
Published: July 2006

Abstract
A computer‐based model is presented that brings together the existing knowledge about the dynamics of bracken in eucalypt forests in south‐eastern Australia. The average length of the growing season, the timing and extent of logging, and the timing and severity of fire are major inputs to the model. The model is predominantly deterministic, but has a stochastic environmental component. The model is validated with four independent sets of data. The model successfully predicts the trends in the data. The interactions between bracken, other understorey species and eucalypt regeneration are explored with the model. The likely effect of different silvicultural and fire management practices on the cover of bracken are investigated using the model. Year to year variation can mask the effects of disturbance if bracken cover is viewed in any one year in isolation. Bracken cover trends can only be seen over a period of 10 years or more. The model reinforces the importance of site productivity as measured by length of growing season and the degree of tree removal on bracken cover.
Inviting trouble: Introduced pasture species in northern Australia
Authors: LONSDALE W. M.
Published: July 2006

Abstract
I surveyed the history of exotic pasture introductions in northern Australia to compare the rate of introduction of useful species with that of weeds. Between 1947 and 1985, 463 exotic grasses and legumes in at least 2033 accessions were intentionally introduced into the region, the grasses predominantly from Africa, and the legumes from Central and South America. Of these, only 21 (5%) came to be recommended as useful, while 60 (13%) became listed as weeds. Seventeen of the useful plants were in fact also weeds, leaving only 4 species (<1%) that were useful without causing weed problems. They were far outnumbered by the 43 species (9%) that were weeds but had no recorded use. Of the 60 weeds, 21 were weeds of cropping, 20 were weeds of conservation and 19 were weeds of both sectors. Thirteen were listed as major crop weeds. Growth rate, maximum height, seed size, and continent of origin were unrelated to weediness. Good predictors of weediness were whether a plant was useful, a good performer in trials, or persisted at a field site. In addition, grasses were more likely, and legumes less likely, to be weedy than expected. It is argued that a new form of assessment is required before an exotic plant species is released into the Australian environment as a pasture plant. This would recognize that a successful introduction is almost certain to become a weed in some situations, and would attempt to assess the net national benefit of the proposed introduction.
Groundwater rise, soil salinization and the decline of Casuarina in southeastern Australia during the late Quaternary
Authors: CROWLEY GABRIEL M.
Published: July 2006

Abstract
The decline in interglacial importance of Casuarina over the late Quaternary across southeastern Australia is documented. Three previously proposed causes for the decline (change in fire regime, change to a wetter climate and competitive exclusion by eucalypts) are shown to be inadequate for explaining the majority of cases. Re‐examination of the evidence shows the decline at most sites occurred synchronously with a rise in groundwater or soil salinization, or both. From a review of biological literature, it is established that Casuarina stricta, the main species considered to have been affected by the decline, is likely to be disadvantaged by high water tables and saline soils. A link is demonstrated between groundwater salinity and the nodulation status of Casuarina in Victoria. It is concluded that the late Quaternary Casuarina decline was caused by a combination of rising groundwater levels and soil salinization. Soil salinization and groundwater level must therefore be considered as major factors determining vegetation patterns in southeastern Australia through the Quaternary up to the present day.
Banksia nectar and pollen: Dietary items affecting the abundance of the common blossom bat, Syconycteris australis, in southeastern Australia
Authors: LAW BRADLEY S.
Published: July 2006

Abstract
The relationship between the abundance of the common blossom bat (Syconycteris australis), a nectar/pollen specialist, and the availability of its food sources was investigated across nine Banksia integrifolia heathland sites in coastal New South Wales, Australia. An index of bat abundance was more highly correlated with direct estimates of food density (productive inflorescences) than indirect estimates of food (Banksia trees and total inflorescences). Furthermore, standing crops of nectar‐energy per hectare were better predictors of bat abundance than pollen‐nitrogen per hectare. Adult male mass did not differ significantly across sites of differing food availability, suggesting that the corresponding increase in bat abundance with food reduces the amount of fat an individual can deposit. Although males and females responded similarly to food, adult numbers were more strongly correlated with food supply and they were more likely to be recaptured than juveniles. Energy requirements of blossom bats exceeded availability in four out of nine sites. Flying foxes were heard feeding in large numbers at the remaining five sites, where energy was superabundant for S. australis. In contrast to the conclusions of previous studies of megabats, these results provide the basis for a prediction that nectar‐energy, rather than pollen‐nitrogen, is the primary limiting factor for populations of the blossom bat.
Do feral honey bees (Apis mellifera) and regent parrots (Polytelis anthopeplus) compete for nest sites?
Authors: OLDROYD BENJAMIN P. , LAWLER SUSAN H. , CROZIER ROSS H.
Published: July 2006

Abstract
Surveys of nesting sites of feral honey bees (Apis mellifera) and regent parrots (Polytelis anthopeplus) were made in the red gum/black box woodlands of Wyperfeld National Park, Victoria, Australia. Data on tree species and size, and number of hollows were collected from all trees within seven 500 × 100m plots. Nest site characteristics were quantified for both bees and parrots. We found 27 feral honey bee colonies, suggesting a density of 77.1 colonies per km2. The average occupation rate for bees was 1.3% of trees and 0.7% of available hollows. The height, aspect and entrance characteristics of honey bee nests at Wyperfeld were not qualitatively different to those reported elsewhere. We found 15 pairs of nesting regent parrots. Nest sites chosen by these birds overlapped those chosen by honey bees, but 52% of bee nests were in cavities unsuitable for regent parrots. We suggest that honey bee population growth may be limited in the park by a lack of water.
The influence of climate on patterns of termite eating in Australian mammals and lizards
Authors: ABENSPERG‐TRAUN MAX
Published: July 2006

Abstract
The present paper examines patterns of termite eating in Australian mammals and lizards (total numbers of species, volume percentage of diet) relative to climate (arid, semi‐arid, temperate‐mesic). Most termite eaters in arid and semi‐arid Australia are lizards. Termite consumptio as a proportion of total lizard diet decreases from arid to mesic climates. More mammal species are relatively termite specialized (>50%) in arid than in semi‐arid and mesic regions. Termite consumption in echidnas resembles that of the lizards: relatively high in the arid and relatively low in the mesic zone. For the Dasyuridae, termites comprise only a minor fraction (< 10%) in their diet, irrespective of climate. It is argued that the climatic peculiarities of inland Australia (scant and variable rainfall) cause marked seasonality in termite availability, supporting specialized termite eaters in only the most energy‐frugal forms (lizards, echidnas). Areas of future research are identified.
The need for biological assessment of water quality: Australian perspective
Authors: NORRIS RICHARD H. , MORRIS K. R.
Published: July 2006

Abstract
Biological assessment of water quality in Australia is entering a stage of rapid development largely because of the inclusion of biological indicators in water quality guidelines and growing concern for ecological values. Approaches to water quality assessment include toxicity testing, use of biomarkers and several methods using community structure. For assessment diverse organisms such as fish, algae and (the most commonly used) macro‐invertebrates are used. Interaction of data analysis with methods of data collection requires co‐ordinated research on both fronts. Recent developments in the use of multivariate statistics to produce models for predicting water quality are likely to be useful in Australia. Much innovative work is still needed in Australia on the use of algae and fish, defining tolerance categories and establishing monitoring programmes performed in time‐frames equivalent to those in use for physical and chemical methods.
Bioassay testing for Australia as part of water quality assessment programmes
Authors: CHAPMAN PETER M.
Published: July 2006

Abstract
Bioassay testing includes both toxicity (one or more effects is measured) and bioaccumulation (the phenomenon of tissue accumulation is measured) tests. Both types of bioassay tests have an important place in water quality assessment programmes, ideally beginning with initial screening and as part of tiered testing that includes contaminant analyses and field studies. Both have advantages (e. g. measure bioavailability, provide quantitative data, experimental manipulations can address cause‐effect relationships) and disadvantages (e. g. laboratory exposures do not necessarily reflect field conditions, not all organisms can be tested). Both provide essential, but not all, information necessary for holistic water quality assessments. This paper provides a review of the use of bioassays including definitions, applications, advantages and disadvantages, utility and relevance. The utility of bioassays in monitoring programmes is illustrated by two case studies. The first case study, involving novel toxicity studies conducted in the high Arctic, illustrates the versatility of bioassays such that testing conducted in a tent on the ice resulted in new knowledge and a change in industrial discharge limits. The second case study further illustrates the importance of bioassays in decision making. In this case, a decision not to immediately spend hundreds of millions of dollars for sewage treatment, but rather to concentrate on source control, was made based in large part on bioassay testing conducted as part of an integrated environmental assessment.
Studies on fish movement dynamics in a tropical floodplain river: Prerequisites for a procedure to monitor the impacts of mining
Authors: BISHOP K. A. , PIDGEON R. W. J. , WALDEN D. J.
Published: July 2006

Abstract
Towards the end of the Wet season in the tropical coastlands of northern Australia, there are dramatic upstream movements of many fish species in some seasonally flowing streams. These movements are considered to be a part of refuge‐seeking migrations. Aspects of the dynamics of the movements in Magela Creek (in the ‘Top End’ of the Northern Territory) downstream from the Ranger Uranium Mine have been examined with a range of techniques (mainly direct observation) to facilitate the development of a possible procedure for monitoring impacts of the mine on the fish community of the creek system. Data on diel patterns of movements validated that monitoring, for 1 h at midday at a single point adjacent to the mine, reflects day‐to‐day changes in total diel movements. To help identify the location of any impacts arising in the future, information on upstream progress rates, longitudinal changes in movements, and movements between the creek and lowland billabongs, were used to (i) demonstrate the creek‐long continuity of movements and (ii) indicate the possible sources and destinations of fish approaching the mine. Marked differences in sources were apparent for two groups of species: terapontids originating from the lowland creek channels, and chequered rainbowfish and ambassids originating from the floodplain and lowland billabongs. Identification of the relative contributions from these habitats will require additional monitoring effort.
Vegetation and environmental patterns on soils derived from Hawkesbury Sandstone and Narrabeen substrata in Ku‐ring‐gai Chase National Park, New South Wales
Authors: LE BROCQUE A. F. , BUCKNEY R. T.
Published: July 2006

Abstract
The vegetation patterns in the Central Coast region of New South Wales have been extensively studied with respect to single environmental variables, particularly soil nutrients. However, few data are available on the effects of multiple environmental variables. This study examines the relationships between vegetation and multiple environmental variables in natural vegetation on two underlying rock types, Hawkesbury Sandstone and Narrabeen Group shales and sandstones, in Ku‐ring‐gai Chase National Park, Sydney. Floristic composition and 17 environmental factors were characterized using duplicate 500 m2 quadrats from 50 sites representing a wide range of vegetation types. The patterns in vegetation and environmental factors were examined through multivariate analyses: indicator species analysis was used to provide an objective classification of plant community types, and the relationships between vegetation and environmental factors within the two soil types were examined through indirect and direct gradient analyses. Eleven plant communities were identified, which showed strong agreement with previous studies. The measured environmental factors showed strong correlations with vegetation patterns: within both soil types, the measured environmental variables explained approximately 32–35% of the variation in vegetation. No single measured environmental variable adequately described the observed gradients in vegetation; rather, vegetation gradients showed strong correlations with complex environmental gradients. These complex environmental gradients included nutrient, moisture, and soil physical and site variables. These results suggest that a simple ‘nutrient’ hypothesis regarding vegetation patterns in the Central Coast region is inadequate to explain variation in vegetation within soil types.
Pollination limitation, costs of capsule production and the capsule‐to‐flower ratio in Dendrobium monophyllum F. Muell. (Orchidaceae)
Authors: BARTAREAU TAD
Published: July 2006

Abstract
In perennial plants, life‐history theory suggests that natural selection should result in the optimization of fruit‐to‐flower ratios within the limits imposed by the trade‐offs between resource allocation for present reproduction and future growth and reproduction. The tropical orchid Dendrobium monophyllum F. Muell., an epiphyte or lithophyte, offers no nectar rewards, is self‐incompatible and has a capsule‐to‐flower ratio of about 1:14. The influence of pollination limitation and the costs of capsule production on capsule‐to‐flower ratios were assessed using experimental and field studies in which individual plants were observed for 3 years. Pollinators visited about 80% of flowers, and capsule production was significantly related to inflorescence size and pollinaria removal. About nine pollinator visits occurred per capsule. Pollinator visitation and capsule production did not vary significantly between years. The inflorescence size classes most successful in capsule production were also the most frequent in natural populations. The experimental supplementation of outcross pollen to flowers increased capsule set over controls by 45% within a year, but was limited to about 53%. A capsule‐to‐flower ratio of 1:2 in experimental plants significantly decreased the subsequent growth and flowering of individuals relative to controls. A capsule‐to‐flower ratio above 1:10 in naturally pollinated plants decreased flowering in the subsequent year. Thus, it is suggested than an increase in capsule production above 10% would not necessarily correlate with greater reproductive fitness because of the increased cost of capsule production. The capsule‐to‐flower ratio recorded in this study could be evolutionarily stable because of trade‐offs between selection for pollinator attraction and the cost of capsule production. The production of surplus flowers appears to function in pollinator attraction and increases fitness through male function.
2nd World Congress of Herpetology
Authors: SINSCH ULRICH , SEIDEL DAGMAR
Published: July 2006

Abstract
Natterjack toads (Bufo calamita) form metapopulations consisting of interacting local and temporal breeding assemblages. The gene flow between simultaneously reproductive local populations is limited at the adult stage to about 2% roaming males and around 20% of females. The gene flow between temporal populations breeding successively at the same locality is based on about 0–15% of males and 0–29% of females reproducing in different temporal breeding assemblages. The annual mortality rate of males ranges between 50 and 60%, corresponding to a maximum life expectancy of about 7 years. The main cause of local extinction is always deterioration of the habitat, namely destruction of the breeding habitat or a dry climate.
2nd World Congress of Herpetology
Authors: BELL BEN D. , BELL A. PAUL
Published: July 2006

Abstract
Surveys of 62 pond sites near Market‐Drayton, Shropshire, were carried out in September 1989 and April‐September 1993 to determine the local distribution of the alpine newt Triturus alpestris, first introduced there in 1970–74. Triturus alpestris was found in garden and farm ponds up to 70 m from the original sites of liberation. Relative numbers and size‐ranges of adult and larval Triturus species (alpestris, cristatus, vulgaris) are compared between study areas. The ecological and conservation implications of T. alpestris in Britain are discussed.
2nd World Congress of Herpetology
Authors: TINSLEY RICHARD C. , TOCQUE KAREN
Published: July 2006

Abstract
The anuran amphibian Scaphiopus couchii occurs in the southwestern deserts of North America where its seasonal activity cycle is strictly regulated by summer rainfall. Breeding populations that assemble after torrential storms have been sampled from the same area of the Sonoran Desert in Arizona from 1981 to 1992. Analysis of growth rings from the bones of S. couchii collected during seven consecutive seasons (1986–92) has enabled a comprehensive reconstruction of population age structure. Females may first breed at 3 years of age and males at 2 years, with a maximum longevity of around 13 and 11 years, respectively. The majority (65%) of breeding animals are at least 5 years old, 33% are 7 years and older and 5% may live for more than 10 years. Studies on the age structure of breeding populations have revealed a series of dominant cohorts which originate in wet summers particularly favourable for reproduction; each cohort can be followed for up to 4 successive years at which time it is replaced by the next dominant age‐group. The annual ring record has shown that individual S. couchii growth rates are highly variable and the width of bone produced each year can be correlated with the amount of summer rainfall (and hence feeding opportunities). During the 12 years of fieldwork, there has been a virtual alternation between wet (1981, 1983, 1984, 1986, 1988, 1990, 1991) and dry (1982, 1985, 1987, 1989, 1992) summers, and 49% of animals show corresponding alternation of thick and thin growth bands. Despite a pre‐metamorphic development period of only 10 days, tadpole mortality is high in ephemeral ponds, and post‐metamorphs are vulnerable during the very restricted period in which they can accumulate reserves for hibernation; however, evidence from the age‐distribution of breeding populations indicates good survival after maturity. Analysis of individual growth rates shows that, in general, faster‐growing animals are not often represented in the older cohorts and that slower‐growing animals tend to live the longest. These studies have shown that the population dynamics of S. couchii in the desert are governed by the duration and intensity of summer rainfall, the effects of which are recognizable in the growth records of individuals and in the age‐structure of breeding populations. The succession of dominant cohorts that results from this environmental variation precludes construction of a general life‐table for S. couchii.
2nd World Congress of Herpetology
Authors: BULL C. M.
Published: July 2006

Abstract
A population of the sleepy lizard, Tiliqua rugosa, near Mt Mary, South Australia, was surveyed by random encounter captures along 42km of transects over a 10 year period from 1982 to 1991. Population size, estimated by the Jolly‐Seber method, was lowest (724 adults) following the 1982/1983 drought, but then increased to a plateau (1500–1600 adults) which was maintained for 5 years. Densities in each 1 km segment of the transects varied from 0. 3 to 5. 5 lizards per hectare. Adjacent segments of the transects varied more than two‐fold in lizard numbers, and those differences were consistent over time. Over all years, an estimated 16% of juveniles survived their first year, 42% of those survived a second year, and 62% of those survived a third year. By the third year some juveniles had reached adult size, although others took more than 5 years to mature. The annual survival of adults of all ages was 80–90%, whereas only 4% of juveniles reached adulthood. Cars killed an average of 3% of the adult population each year, and were a major source of mortality. To sustain stable populations adults must live 20–50 years. This long‐lived species has a population structure governed by low recruitment, but long survival of established adults. It differs from the rapid turnover dynamics reported for many other lizard species.
2nd World Congress of Herpetology
Authors: Bruce Richard C.
Published: July 2006

Abstract
Temporary removal sampling was used to investigate the population dynamics of the salamander Desmognathus monticola in the southern Appalachian Mountains, USA. Sampling was conducted over 5 years, mainly in July, on one or two plots each year, with seven removal samples being taken in each set of samples. By using size‐frequency distributions, it was possible to separately estimate population numbers for three juvenile age‐classes and a mixed age‐class of older individuals that included adults. Repetition of the procedure in successive years provided data for both time‐specific (vertical) and cohort life tables. Fecundity values obtained by dissection and age data derived by skeletochronology provided a means for refining the life table. The results confirmed and extended earlier findings of life‐history traits of D. monticola, and showed that annual survival rates of 0.5–0.6 are required for population equilibrium. Removal sampling is considered to be a promising technique for evaluating demographics in multispecies communities of desmognathine salamanders, but requires intensive sampling of relatively large plots over several years.
Competitive effects of Rattus lutreolus presence on food resource use by Pseudomys gracilicaudatus
Authors: LUO JIA , FOX BARRY J.
Published: July 2006

Abstract
We examined faecal samples of the eastern chestnut mouse (Pseudomys gracilicaudatus) that were collected during a removal experiment conducted in a coastal heathland at Myall Lakes National Park to see whether removal of the swamp rat (Rattus lutreolus) had any effects on food resource use by P. gracilicaudatus. The results showed that, at the young successional stage of vegetation (1. 5 years since last fire), the diet of P. gracilicaudatus changed significantly after the number of R. lutreolus was significantly reduced on the experimental sites. Two months after the removal treatment was terminated there were no significant differences between the control and experimental sites. Factor analysis showed that seasonal change was significant for all three food factors on the control sites, whereas on experimental sites the change was significant only for factor 1. At the middle successional stage (3.5 years since last fire), P. gracilicaudatus showed relatively small seasonal changes on both control and experimental sites, and significant differences between the control and experimental sites did not occur until after the removal manipulation was completed, showing a delayed response. Comparisons of the young and the middle successional stages on both control and experimental sites showed that P. gracilicaudatus used proportionally different food when R. lutreolus was present, but consumed similar food when R. lutreolus was removed. These results suggest that R. lutreolus might have restricted the access of P. gracilicaudatus to better microhabitats, and hence to a better food supply. The ecological implication of these results is that the interpretation of observed population and community patterns must take into account the direct effects of species interactions.
Plant coexistence in coastal heaths: Habitat segregation in the post‐fire environment
Authors: MYERSCOUGH PETER J. , CLARKE PETER J. , SKELTON NICHOLAS J.
Published: July 2006

Abstract
Previous studies of heaths on Pleistocene coastal sands showed consistent variation in patterns of floristic composition between areas on ridges and slopes but not within them. A large wild‐fire that swept this system provided an opportunity to observe temporal processes in habitat segregation of species. Ridges and slopes were found to differ in species richness of seedlings in 0.0625 m2 quadrats and there was no evidence that the species richness in the two habitats was converging over 3 years. This suggests that initially these processes differ in space between the two habitats with more species in the wet heath being packed into a smaller area than in the dry heath. Seed‐banks of species did not saturate available space for recruitment in either habitat, but seedling densities differed asymmetrically between habitats across two pairs of species studied. Experimental manipulation of seeds among habitats also showed distinct differences in establishment and survival among representative species from different habitats. The presence of seed‐banks of wet‐heath species in dry heath suggested that recruitment of their seedlings may occur there, but experiments showed that seedlings that arise from them do not survive there. Conversely, although no seed‐bank of either dry‐heath species studied was found in wet heath, our manipulations showed that their seedlings could grow there. Thus, superficially, physiological tolerance appeared to limit regeneration of wet‐heath species in dry heath. However, there appeared to be no physiological limit for dry‐heath plants to survive in wet heath. This paper shows that segregation of species may operate at either of two stages of the life cycle: at dispersal when safe sites for establishment are required, and at recruitment after seedlings have established. These findings highlight the importance of the regeneration niche in structuring community composition in coastal heaths, and contrast with traditional explanations of species segregation invoking physiological tolerance and competition at later life‐history stages.
Are Protea populations seed limited? Implications for wildflower harvesting in Cape fynbos
Authors: MAZE KRISTAL E. , BOND WILLIAM J.
Published: July 2006

Abstract
Little is known about the extent to which plant population growth is limited by seed production. We studied two non‐sprouting Protea species, both entirely dependent on seeds for recruitment after fire, to determine how flower harvesting would affect the size of the next generation after burning. Five harvesting treatments (0, 25, 50, 75 and 100% inflorescence removal) were applied, each replicated four times in 10 × 10m plots. Seedbanks were censused before a late‐summer burn for each species and each replicate. The mean proportion of seeds surviving the burn until germination the following spring was 0.46 for Protea repens and 0.57 for Protea neriifolia. Of the seedlings that emerged, 90% and 55%, respectively, survived the first summer drought. Flower production in the 9 year old stand was strongly related to population density. Optimal plant densities for maximum flower production were estimated as 150 for P. repens and 70 for P. neriifolia. These target densities were greatly exceeded by seedling populations surviving the first summer drought in unharvested stands. If future density‐independent mortality is negligible, the excess represents that part of the seedbank that could have been harvested before the burn without influencing future flower production. We developed a simple static model for setting flower harvesting levels in these seed‐saturated populations. The predicted harvesting levels (50% of inflorescences in P. repens and 85% in P. neriifolia) were validated against the experimental harvests. We discuss the sensitivity of harvesting levels to variation in fecundity/density relationships, seed survival through a burn and seedling survival until flowering, and the implications for flower harvesting.
Seasonal and successional dietary shifts of two sympatric rodents in coastal heathland: A possible mechanism for coexistence
Authors: LUO JIA , FOX BARRY J.
Published: July 2006

Abstract
Using microscopic analysis of faecal pellets, we compared the seasonal and successional patterns of food resource use of two Australian native rodents, the eastern chestnut mouse (Pseudomys gracilicaudatus) and the swamp rat (Rattus lutreolus) in a coastal heathland at Myall Lakes National Park, New South Wales. Using the Mantel test, the diets of the two mammal species were significantly different in autumn and winter but not in spring and summer. Further, the two species showed differential use of resources at the young and middle‐aged stages of vegetation succession following fire. The mean dietary overlaps for pairs of individuals between the two species were relatively high in all seasons and successional stages, but they were significantly lower than those for pairs of individuals within each species in autumn and winter, and at the young and middle successional stages. Analysis of dietary niche position (γ) and breadth (β) showed lower γ and larger β for P. gracilicaudatus than for R. lutreolus, confirming previous observations that R. lutreolus is more specialized, and less opportunistic in diet than P. gracilicaudatus. Overall, the dietary separations of the two species were less marked in canonical space than they were for specific seasons and successional stages. These results, together with previous studies, indirectly suggest that while these two mammal species may be partitioning diet in autumn and winter in the middle stages, for spring and summer in the old successional stage they might need to partition habitats to facilitate their coexistence. Our results indicate that the local community is more dynamic and complex than previously thought and that other mechanisms of coexistence (e.g. temporal rotation of food resources) may be operating rather than traditional habitat and diet separation.
The macrofaunal community of Ecklonia radiata holdfasts: Variation associated with sediment regime, sponge cover and depth
Authors: SMITH STEPHEN D. A.
Published: July 2006

Abstract
The relationship among the Ecklonia radiata holdfast macrofaunal community, sediment content and sponge cover was evaluated for data collected over a four year period at Coffs Harbour, mid‐north coast, New South Wales. While several taxa demonstrated significant relationships with these factors, the correlations explained a maximum of 24% of the variation in the data and explanatory power was consequently low. Differences in the composition of the holdfast community were also evaluated at two depths (2m and 6m) at two sites in a mensurative field experiment conducted in summer and winter 1991. The results of both ANOVA and non‐parametric multivariate statistical analyses (MDS, ANOSIM, SIMPER) indicated that there were consistent, significant differences between depths over the two sample times. Although some common species demonstrated significant associations with one depth, small differences in the abundance of a large number of species were primarily responsible for the overall differences in community structure between depths. Sediment content and holdfast age were both significantly greater in samples collected from 6 m which may account for some of the depth‐related faunistic differences. However, the overall differences between depths are probably related to unmeasured factors such as turbulence due to wave action and holdfast morphology which covary with depth. The results highlight the enormous variability associated with the Ecklonia radiata holdfast macrofaunal community and the consequent necessity to consider as many factors as possible in comparative studies of community structure.
Comparison of regeneration following burning, clearing or mineral sand mining at Tomago, NSW: II. Succession of ant assemblages in a coastal forest
Authors: JACKSON G. P. , FOX BARRY J.
Published: July 2006

AbstractThe dry sclerophyll forest community of the Tomago Sandbeds, near Newcastle in New South Wales, has been subject to regular disturbances due to fire, clearing and strip mining for over 18 years. In this study we use chronosequence analysis to examine whether the structure of the ant community varies with the type of disturbance and the time since disturbance. We treat the recovery trajectory after fire as a control trajectory because fire is an endogenous disturbance. The main analyses were based on an ant fauna comprising 72 species sampled from 44 sites surveyed in December 1992. Comparison with samples taken in April and December 1991, and for cumulative records for all sites over this 20 month period, all show quantitatively similar responses. Results suggest that while fire has a minor effect on the composition of the ant community over time, the impact of clearing and mining is much more severe. Ant species richness at cleared and mined sites recovers rapidly, overshoots controls in mid‐succession and returns to control levels by 18 years after disturbance. The cumulative number of species recorded over all sites (from the total recorded fauna of 82 species) for each different disturbance type were: burned, 61; cleared, 55; and mined 56. Species composition at cleared or mined sites, after 18 years, approaches but does not match controls. The recovery trend for mined sites lags slightly behind that for cleared sites, which have reached 49% similarity with the oldest burned sites, while mined sites have not exceeded 39% similarity of species composition. The main patterns in the ant community appear to be related to habitat variables. These results provide further evidence that the ant community may be used as a reliable bio‐indicator for evaluating the extent of habitat damage and recovery after disturbance in these Australian forests.
Branchlet shaking: A method for sampling tree canopy arthropods under windy conditions
Authors: MAJER JONATHAN D. , RECHER HARRY , KEALS NATALIE
Published: July 2006

Abstract
Chemical knockdown is a commonly used method for sampling canopy arthropods. The procedure is susceptible to high winds and in certain conditions may be virtually unusable. Here we introduce a new procedure, branchlet shaking, and compare it with chemical knockdown. Samples produced by branchlet shaking yield fewer arthropods per tree and tend to miss some larger (>1.0cm) and some smaller (<0.2cm) animals. However, the two procedures generally produce data which can portray similar information about the canopy fauna. It is concluded that although chemical knockdown is a superior sampling procedure, branchlet shaking is a possible alternative for situations where chemical knockdown is impractical. Interpretation of the data must, however, take into account the limitations of the branchlet shaking procedure.