bluuebunny/crossref_metadata_2025 huggingface dataset:
A winter's tale: Among‐year variation in bird community structure in a southeastern Australian forest
Authors: MACNALLY R.
Published: July 2006

Abstract
The bird community structure of an undisturbed forest (Olinda State Forest) east of Melbourne, Victoria, varied greatly among the winters of 1993, 1994 and 1995. Increases in the total density of all diurnally active species were as much as 66% between winters [381 versus 633 birds per 50 ha (the density unit used throughout)]. Community structure differed significantly among all three winters, although 1993 and 1994 differed most (1995 was intermediate). One of the striking features was the heterogeneity in patterns among species, families and foraging guilds over the three winters: some taxa (guilds) showed significantly higher densities in the middle year (1993 < 1994 > 1995), others increased monotonically (1993 < 1994 < 1995), while others increased from 1993 to 1994 and maintained those densities in 1995. The species showing significantly higher densities in 1994 were mostly nectarivorous, which seemed to accord with profuse and sustained flowering by Eucalyptus cypellocarpa in 1994 alone. The results are discussed in the context of non‐equilibrial community dynamics, large‐ versus small‐scale processes, and the implications of this magnitude of variation in unperturbed forests for environmental monitoring and impact assessments.
Modelling the response of eucalypts to fire, Brindabella Ranges, ACT
Authors: STRASSER MICHAEL J. , PAUSAS JULI G. , NOBLE IAN R.
Published: July 2006

Abstract
A new algorithm for the responses of Eucalyptus species to fire was developed to be used in BRIND, an existing forest gap simulation model. After a fire, trees may be: (i) killed outright; (ii) have their above‐ground parts killed but resprout from basal lignotubers; or (iii) continue to grow from undamaged and epicormic above‐ground buds. Data collected after a fire in the Gudgenby region, Brindabella Ranges, southern Australian Capital Territory, indicate that tree size and vigour can be used to predict the response of individual trees. There was not enough information about fire intensity to estimate its effect on the response of trees. The new algorithm was tested using data from a 1982 fire in Bushrangers Creek, Brindabella Ranges. The predicted probabilities of stem death were similar to the field data.
How old are Wet Forest understories?
Authors: MUECK STEPHEN G. , OUGH KEELY , BANKS JOHN C. G.
Published: July 2006

Abstract
Radiocarbon ages were derived from 12 individuals representing four species of woody understorey plants growing in the Eucalyptus regnans dominated Wet Forests of Victoria's Central Highlands. Cyathea australis, Dicksonia antarctica and Olearia argophylla are common and often dominate the understorey. The fourth species, Persoonia arborea, is a small understorey tree endemic to this region. Field observations and radiocarbon ages for these four species (up to 370 ± 70 years BP) indicate they are capable of surviving fire and are long‐lived in this environment.
How New Guinea rainforest flower resources vary in time and space: Implications for nectarivorous birds
Authors: BROWN ELEANOR D. , HOPKINS MICHAEL J. G.
Published: July 2006

Abstract
Variability in spatial and temporal patterning of flowering by populations of rainforest trees fed upon by honeyeaters and flower‐visiting parrots was studied for 2 years in lowland tropical hill forest in Papua New Guinea. All 2200 trees in a 3 ha plot were tagged, identified, mapped and monitored monthly. Of 274 tree species present, 86 flowered during the course of the study; during any given month, approximately 20% of the species flowering that month were visited by nectarivorous birds. Results showed that overall flower resources (total number of species, and number of bird‐pollinated species, individuals and flowers) fluctuated during the year, decreased during the dry season and increased during the wet season. In addition, there was a wide range of temporal variation within and among tree species in length and timing of flowering period, percentage of each conspecific population flowering from year to year, and degree of synchrony among flowering conspecifics. Spatial dispersion of tree populations also varied, from clumps to scattered single individuals. Resident bird species were correlated with synchronously flowering trees, whereas nomadic bird species were correlated with asynchronously flowering trees. Resident birds were also associated with smaller blooming displays per tree, whereas nomadic birds were associated with trees that bloomed massively. There was no correlation between avian nomadism and spatial dispersion of tree populations. Thus nomadic birds seem to range in search of rich but unpredictable resources; resident birds may rely more on predictable, but smaller resources.
The effects of fire on the frillneck lizard (Chlamydosaurus kingii) in northern Australia
Authors: GRIFFITHS A. D. , CHRISTIAN K. A.
Published: July 2006

Abstract
A population of frillneck lizards, Chlamydosaurus kingii, was monitored by radio telemetry and mark‐recapture techniques between April 1991 and April 1994, as part of a landscape‐scale fire experiment, in Kakadu National Park, Northern Territory. The study aimed to investigate both the short‐ and longer‐term effects of fire on a lizard species in a tropical savanna where fires are frequent and often annual. Frillneck lizards are able to survive fires that occur in the first few months of the dry season by remaining perched in trees. A high level of mortality (29%) occurred during late dry‐season fires, along with changes in their behavioural response to fire: sheltering in either larger trees or hollow termite mounds. Food is more accessible after fires due to the removal of ground vegetation. This is reflected in greater volume and diversity of prey in stomach contents after fires. This increase is more pronounced after late dry‐season fires, possibly due to increased accessibility of prey caused by more complete vegetation removal. Frillneck lizards show an overall preference for trees with a dense canopy cover located in an area with a low density of grass. Fire has an effect on this relationship. Frillneck lizards in habitat unburnt for a number of years tend to perch in trees with a smaller canopy, whereas lizards in annually burnt habitat perch in trees with a dense canopy. Volume and composition of lizard stomach contents was broadly similar among fire treatments over a 2 year period, although termites were more predominant in stomach contents of lizards in unburnt habitat. Wet‐season body condition is lower in lizards from unburnt habitat, although the reason for this is unclear. These results demonstrate the importance of different fire intensities and regimes on the ecology of a lizard species in a tropical savanna.
The late Quaternary vegetation history of the south‐central highlands of Victoria, Australia. I. Sites above 900 m
Authors: MCKENZIE G. MERNA
Published: July 2006

Abstract
The late Quaternary vegetation communities of the south‐central highlands of Victoria are reconstructed from analyses of pollen and charcoal, and associated environmental conditions derived from the record of Nothofagus cunninghamii and alpine and sclerophyll taxa preserved in four subalpine Sphagnum bogs. The highest site occurs amid Eucalyptus paudflora woodland, the two intermediate sites are surrounded by Eucalyptus delegatensis forest and the lowest by a mixed forest of E. delegatensis/Eucalyptus regnans. Small pockets of N. cunninghamii occur within the eucalypt forests, and in close proximity to all four sites. Around 32 000 BP the vegetation consisted of a mosaic of alpine feldmark and herbfield, with small scattered groves of Nothofagus and Eucalyptus well below 1100m. Summer temperatures were probably 5°C lower than present with lowest values, probably 7° to 8°C below present, possibly between 17 000 and 13 500 BP, at which time alpine communities reached their greatest extent and much of the Central Highlands was treeless. After ca 13 500 BP herbaceous alpine taxa disappeared and there was an associated movement upslope of Nothofagus and tall open forest taxa to their maximum post‐glacial extent, as temperatures and effective precipitation increased, ca 6000 BP. The retraction of cool temperate rainforest and wet sclerophyll or tall open forest towards present day values indicates lower effective precipitation, generally rising temperatures and increased fire hazard. More recently, European activities have increased the stress on the remaining forests. The study of four sites has demonstrated die importance of analysing a number of sites within a given area in order to overcome the limitations imposed by sites which were sub‐optimal due to one or more factors including poor preservation, problems of dating, variable sedimentation rates, and the influence of streams which flow close to all sites. While die local environment varies between sites, and some vegetation changes are successional, this study shows that the local records complement one another, to some extent reinforcing die regional picture of vegetation and environmental change.
Influence of suburban edges on invasion of Pittosporum undulatum into the bushland of northern Sydney, Australia
Authors: ROSE STEFAN
Published: July 2006

Abstract
Suburban edges are shown to exert a major influence on invasion of the native Pittosporum undulatum Vent, in dry sclerophyll bushland of northern Sydney. Transect data from fifteen urban bushland sites spanning approximately 90 years of development indicate significant increases of P. undulatum with time. Basal area, density and frequencies of plants in all size‐classes increased significantly with age of adjoining development. Mean basal area at edges of old sites was 5700 times greater than in comparable bushland in larger reserve interiors. The effect of age was compounded by the greater impact of edge effects in narrower reserves of older suburbs. Basal areas and proportion of reproductive plants decreased significantly with distance into the reserve. Older sites contained larger but fewer individuals at the edge, compared with high densities of smaller plants further into the reserve, suggesting an advanced successional stage. The overall relationship of density with distance was not significant. The observed clumping of seedlings beneath canopies is consistent with previous work on seed dispersal by vectors, and enhanced seedling recruitment in safe sites. Pittosporum basal area and density reached no maximum levels with age, implying ongoing invasion. The study indicated some factors which appeared to promote the establishment of P. undulatum in the study area. Signs of fire were negatively correlated across all sites with basal area and density of P. undulatum. Human disturbance was positively correlated with the same variables. On the basis of findings in this study, some broad priorities for management of Pittosporum in urban bushland are suggested.
Distribution of social crab spiders in eucalypt forests
Authors: EVANS T. A.
Published: July 2006

Abstract
Social crab spiders (Thomisidae, Diaea) are found in Eucalyptus forests of varying latitude, altitude and species composition in southern Australia. Neither temperature nor rainfall differ between areas where social Diaea are found, suggesting that spiders have a preferred climatic range, and that they change altitudes at different latitudes to maintain their preferred range. In these areas, those Eucalyptus species that hosted Diaea had smaller leaves and fruit than eucalypts that did not, which suggests that the spiders may choose trees based on leaf morphology.
The abundance of ground‐dwelling invertebrates in a Victorian forest affected by ‘dieback’(Phytophthora cinnamomi) disease
Authors: NEWELL GRAEME R.
Published: July 2006

Abstract
Phytophthora cinnamomi (cinnamon fungus) is a pathogenic soil fungus that infects plant communities along the southeastern coast of Australia and the southwestern corner of Western Australia. Infection of native plant communities with P. cinnamomi regularly leads to dramatic changes in both the structural and the floristic characteristics of these communities. This study aimed to assess the effect of P. cinnamomi induced changes in plant community attributes upon the abundance and diversity of invertebrates in an area of open forest in the Brisbane Ranges, Victoria. Pitfall trapping was conducted continuously for 1 week within each season over a 3 year period. Invertebrates were sorted to order level, and abundances were compared between times (season and year) and infection status for taxa with normalized distributions (Coleoptera, Collembola, Dermaptera and ants). Non‐parametric comparisons were made for other groups (Aranae, Blattodea, Diptera, Hemiptera, Orthoptera, ant ‘morpho‐species’ and unidentified larvae) to assess differences on the basis of infection status. Significant differences on the basis of infection were uncommon and, where identified, elevated abundances were more commonly observed at sites infected by P. cinnamomi. Consistent temporal effects (season and year) were observed in normalized data sets. Abundances both within individual taxa and from pooled counts were generally weakly associated with ground‐level habitat features. Overall, the impact of P. cinnamomi on vegetative structure and floristics was not reflected in different abundances of ground‐dwelling invertebrates.
Fish use of an inundated saltmarsh flat in a temperate Australian estuary
Authors: CONNOLLY R. M. , DALTON A. , BASS D. A.
Published: July 2006

Abstract
Fish associated with Australian saltmarshes have previously been sampled from within creeks or semi‐permanent pools on the marsh; this is the first record of fish use of marsh flats inundated on high tides but emergent on low tides. Buoyant pop nets (9 m2, 1 mm mesh) were used to collect fish from two areas of the marsh flat on Torrens Island in the Barker Inlet‐Port River estuary. South Australia. Fyke nets of the same mesh size were used to collect fish from small creeks draining the marsh flat. Fish were caught in only four of 48 pop net releases, for a total of 19 fish of two species (families Gobiidae and Atherinidae). A total of 1109 fish from six species were caught in creeks draining the same areas, and the two species caught on the flats were the most common species in the creeks. Economically important species were poorly represented, with just four specimens of the mugilid Aldrichetta forsteri (Valenciennes).
Distinguishing area and habitat heterogeneity effects on species richness: Birds in Victorian buloke remnants
Authors: NALLY R. MAC , WATSON D. M.
Published: July 2006

Abstract
Resolving whether area per se or habitat heterogeneity has the greater influence in controlling species richness remains a controversial yet important question. Here we show that avian species richness of same‐sized transects (1 ha) is independent of the remnant area (of buloke woodland) within which a transect is positioned. We also show that avi‐faunal similarity of pairs of transects randomly placed within the largest remnants (≥ 48 ha) is not consistently related to either proximity (i. e. being within the same remnant) nor to physiognomic characteristics of the transects. We believe that much of the controversy over area/habitat heterogeneity effects is probably related to scalar issues and propose a protocol by which some resolution of the question might be reached. The protocol involves ‘zoom’ sampling in which successively larger transect sizes are used, and measures of faunal richness and habitat heterogeneity are made at these different grains of resolution. One of our intentions is to stimulate discussion on how heterogeneity might be measured when grains increase from typical transect sizes (ca 1 ha) up to much larger grains (ca 128 ha).
Costs and benefits of facultative aggregating behaviour in the orb‐spinning spider Gasteracantha minax Thorell (Araneae: Araneidae)
Authors: LLOYD N. J. , ELGAR M. A.
Published: July 2006

Abstract
The potential costs and benefits of foraging in aggregations are examined for the orb‐spinning spider Gasteracantha minax. Web‐site tenacity is low in this species; individuals frequently move among sites, thereby joining aggregations of different sizes. Female spiders in aggregations suffered lower predation rates and attracted more males than their solitary counterparts. However, aggregated eggsacs, probably produced by females in aggregations, experienced higher rates of parasitism than solitary eggsacs. We found no evidence of higher prey capture success rates among spiders in aggregations. However, we demonstrate a novel way in which spiders can increase their foraging efficiency by decreasing silk investment. A spider spinning a web within an existing aggregation can attach the support threads of its web to those of other webs, thereby exploiting the silk produced by other spiders.
Impact of fuel‐reduction burning on the frog Geocrinia lutea in southwest Western Australia
Authors: DRISCOLL DON A. , ROBERTS J. DALE
Published: July 2006

Abstract
The four frog species in the Geocrinia rosea complex occur in state forest in southwest Western Australia. Fire management of these forests involves fuel‐reduction burning with an average rotation of five to nine years. In this study we examined the impact of fire on Geocrinia lutea by counting calling males in six pairs of burned and control sites from 1992 to 1994. The immediate impact of the fire on G. lutea adults, and the survival of G. lutea eggs and larvae after the fire, were also addressed. We found that fuel‐reduction burning in spring was associated with a significant decline in the number of calling males. The populations had not recovered two years after the fire. Up to 29% of the calling males may have been killed in the fire. Egg and larval survival was not significantly different between treatments. However, the treatments did differ in the cause of death, with higher in‐situ egg death and lower predation at burned sites. The short‐term impact of spring fuel‐reduction burns may pose a serious threat of extinction for very small populations. The endangered species Geocrinia alba has many small, isolated populations and frequent fire may therefore be inimical to their survival. However, we do not know if there is a long‐term effect. Populations may or may not have time to recover between fires.
Fruit‐seed relations in Hakea: serotinous species invest more dry matter in predispersal seed protection
Authors: GROOM PHILIP K. , LAMONT BYRON B.
Published: July 2006

Abstract
The ability to maintain a canopy stored seedbank (serotiny) is characteristic of many woody genera inhabiting fire‐prone environments. The relationship between level of serotiny for 94 Hakea (Proteaceae) species in southwestern Australia and follicle mass, density, three wall thicknesses and seed mass was investigated. Two species were non‐serotinous (fruits open at maturity), 12 were weakly serotinous (majority of fruits open at maturity), 9 were moderately serotinous (fruits open within five years of maturity) and 71 were strongly serotinous (fruits still closed at least five years after reaching maturity). A positive relationship existed between the level of serotiny and follicle morphology. Strongly serotinous species were more likely to have heavier, woodier and thicker‐walled follicles than non‐ and weakly serotinous species. Moderately/strongly serotinous species invested more energy (six times higher follicle:seed mass ratio) than non weakly serotinous species, consistent with increased protection of the seeds from granivores, pathogens, desiccation and/or heat. Recent work has shown that thicker fruit walls (strongly serotinous species) provide better insulation to seeds from heat, although the need to survive fire is just as critical for thin‐walled, weakly serotinous species. Greater protection from granivores may provide a better explanation for the adaptive significance of dense, thick‐walled serotinous follicles, as the opportunities for predispersal granivore damage are low among weakly serotinous species.
The effects of foraging by the superb lyrebird (Menura novae‐hollandiae) in Eucalyptus regnans forests at Beenak, Victoria
Authors: ASHTON D. H. , BASSETT O. D.
Published: July 2006

Abstract
In an early spar‐stage stand of Eucalyptus regnans at Beenak, Victoria, foraging by lyrebirds in bare floor areas on steep slopes results in a complex microtopography of excavations, accumulations and terracettes. About 200 t ha−1 of litter and top soil may be displaced an average of 70 cm downhill per year. Magnetic ferruginous pisolite was used as a marker to monitor progressive soil movement over 3 years. Very little disturbance occurred in areas of dense ground fern, but in bare areas the whole forest floor may be turned over every 20 months. In the site studied, foraging activity by lyrebirds varied seasonally and topographically. Disturbance by other biotic agents was minimal. The mean depth of soil cultivation was about 10 cm and litter was frequently buried or mixed intimately with soil. Since buried leaf litter decays more quickly than that on the surface, lyrebird foraging is likely to increase the rate of nutrient cycling. The small, steep clifflets left at the uphill limits of each scratch microsite provide litter‐free niches for the establishment of tree fern prothalli and shade‐tolerant herbs. All stages in the growth of the rough tree fern, Cyathea australis, were present in bare floor areas, but in dense ground fern patches, young stages were confined to rotten logs and upturned root balls. Since dense tree fern development tends to diminish the cover of dense ground fern, lyrebird foraging activity may maintain an accessible food resource which would otherwise diminish with increased ground fern cover in these forests in the course of secondary succession after fire.
The importance of green seed in the nitrogen nutrition of the Zebra Finch Taeniopygia guttata
Authors: ALLEN L. R. , HUME I. D.
Published: July 2006

Abstract
Australian grass‐finches are widely reported to consume large quantities of green seed when it becomes available, and the opportunistic breeding of wild Zebra Finches in the arid zone has been correlated with the occurrence of rain. In this study, green and ripe seeds were harvested from seven pasture and weed grasses grown in experimental plots and, along with three cereal flours and whole‐egg powder, were analysed for the amino‐acid composition of their protein. The relative levels of ten amino acids essential in the diets of growing birds were compared between samples using a cluster analysis dendrogram generated from Raabe's Similarity Index. The protein of all green seeds clustered with whole egg, and away from all but one of the ripe seeds and seed products. Green and ripe seed profiles were found to be significantly different by a two‐sample multivariate test of significance (Hotelling's T2). Histidine, lysine, phenylalanine and threonine were the amino acids most different. Of these four amino acids, lysine and threonine (along with methionine) were potentially limiting in ripe seeds when compared with whole‐egg protein. In green seeds, lysine was only marginally limiting, threonine was no longer limiting, but methionine was still limiting when compared with whole‐egg protein. These results indicate that the benefit of green vs ripe seed in the diet of breeding Zebra Finches is partly a higher level of the limiting essential amino acid, lysine, and partly a higher intake and throughput of soft green seed and consequent greater extraction of limiting essential amino acids.
Increased nest cofounding and high intra‐colony relatedness in the bee Exoneura bicolor (Hymenoptera: Apidae): Results from an experimental situation
Authors: HURST P. S. , GRAY S. , SCHWARZ M. P. , TILLY J. A. , FORAN A. C. , ADAMS M.
Published: July 2006

Abstract
Identifying differences in a key social trait between two populations of die same species is important for understanding the evolution of sociality. Previous studies of new colonies in Exoneura bicolor, an Australian allodapine bee, have shown that there are high levels of kin cofounding in a montane population. The only study to examine intra‐colony relatedness in a heathland population has found that new multifemale colonies are not formed by kin. In this study we used an experiment to investigate both cofounding behaviour and intra‐colony relatedness in E. bicolor from a heathland population. Nest substrate was placed either 0.05 or 1 m distant from source nests in a novel environment. Although there were no differences in cofounding rate or intra‐colony relatedness between die two treatments there was, overall, a high rate of cofounding: 53% of new nests were multifemale, approximately twice as high as found in previous field‐based studies. Relatedness among cofoundresses was not only different from zero, r± SE = 0.597 ± 0.097, but almost identical to that found in montane populations. A constraint, such as nest substrate distribution, is suggested as a proximate factor affecting the expression of cofounding behaviour in E. bicolor. The implication of such proximate constraints for inferring the phylogenetic origins of social behaviour is discussed.
Recruitment of the invasive ornamental, Schinus terebinthifolius, is dependent upon frugivores
Authors: PANETTA F. D. , MCKEE J.
Published: July 2006

Abstract
Generalist avian frugivores often play an important role in the processes of naturalization and invasion for plants introduced for ornamental and landscaping purposes. We investigated the potential role of Australian birds in the current invasion of riparian habitats and coastal wetlands by the ornamental Schinus terebinthifolius Raddi. Feeding trials in captivity predicted silvereyes (Zosterops lateralis Latham) as dispersal vectors for this weed. There were no differences in either total germination or germination rate between seeds voided by caged silvereyes and those from which exocarps had been removed manually. Germination of seeds incubated within entire fruits was minimal, as was emergence from intact fruits in a field experiment. Seed banks of S. terebinthifolius were relatively transient under field conditions, with no seeds surviving for 9 months. Since fewer than 5% of the seeds in sown whole fruits gave rise to seedlings (cf. 20–42% for sown bare seeds), we conclude that recruitment potential of S. terebinthifolius is highly dependent upon the consumption of its fruits by frugivores.
Latitudinal gradients in the species richness of Australian termites (Isoptera)
Authors: ABENSPERG‐TRAUN MAX , STEVEN DION
Published: July 2006

Abstract
Using data on the geographic range of 260 described species in the Atlas of Australian Termites, seven ‘regions’ with more complete data, across a wide range of latitudes were selected for further analysis. For these regions, mean species richness (± SE) was calculated for (i) all species from all families, (ii) Termitidae (197 spp.), (iii) Amitermes spp. (Termitidae, 58 spp.), (iv) all families excluding Amitermes spp. (139 spp.), (v) Termopsidae (5 spp.), (vi) Kalotermitidae (32 spp.) and (vii) Rhinotermitidae (25 spp.). In addition, we compared the Atlas data with species richness for five regions, across a comparable range of latitudes, based on the pooled species richness of described and un‐described species given in community studies. No group of termites showed a consistent decline in species richness from tropical to temperate latitudes for either data set. The Atlas data showed similar total species richness from the tropics to the mediterranean southwest, before declining to lowest species richness at the highest latitudes. Species richness of Amitermes spp. and Rhinotermitidae was highest in the southwest. Termopsidae and Kalotermitidae showed no latitudinal pattern in species richness. Community studies showed highest and lowest total species richness in the southwest and at the highest latitudes (south‐coastal Western Australia), respectively, and similar species richness from the tropics to arid central Australia. Species richness of. Amitermes spp. was highest in the southwest (31 spp.). Kalotermitidae and Rhinotermitidae showed no clear latitudinal pattern.

The latitudinal patterns of species richness for the Australian termites is consistent with that for the Australian vertebrates and ants in that they differ from patterns established for these taxa on other continents.
Scaling of colonization processes in streams: Parallels and lessons from marine hard substrata
Authors: DOWNES BARBARA J. , KEOUGH MICHAEL J.
Published: July 2006

Abstract
Understanding colonization processes specifically requires a comprehensive understanding of the frequency and scales over which dispersal occurs, which in turn determines the degree of linkage within and between populations and possibly results in metapopulation structure. What is our level of such knowledge for stream systems? We examine colonization processes in streams using a framework produced by analogous literature on sessile, marine species, which are comparatively well‐known and may provide insights for stream biota. For simplicity, we separate dispersal into two, somewhat artificial scales: microscale (between habitat patches ‐ cm to m) and mesoscale (between groups of patches ‐ tens to thousands of metres), and consider dispersal links between them. Traditional views on dispersal developed similarly in both systems, with a strong initial focus on mesoscale dispersal followed by an awareness that some species do not disperse usually over these scales and that there are a wide range of dispersal profiles. In both habitats, there are few data on actual dispersal distances, and longevities are sometimes used to infer them instead. Organisms can be transported by water currents (marine larvae, stream larvae) or wind (adult insects), the directions and strengths of which are relatively predictable at mesoscales. However, behavioural choices of organisms during dispersal can change their potential dispersal distances and directions markedly. Additionally, predictability of transport processes at microscales is very poor. As a consequence, simple, lone biological measures (like longevity) or simple, lone physical measures (like discharge) are useless for predicting dispersal frequencies and scales in most cases. Mortality during dispersal is also extremely important but there are few data; this represents a major information gap in both sets of literature. Finally, if organisms end dispersal by searching for and being able to respond to specific cues, then we may be able to predict colonization by looking at the distribution of such cues; different cues are likely though to vary greatly in space and time. There is potential for dispersal ‘structure’ to develop in rivers of different hydrology, and for sets of correlated life‐history characters to result in dispersal at particular scales, but there are very few stream studies that bear on these issues unambiguously. Progress in understanding the scales of dispersal, in both habitats, will require a lot more studies designed formally to test clear hypotheses about the scales of dispersal, rather than continuing a status quo of generating essentially anecdotal information
Predicting impact of freshwater exotic species on native biodiversity: Challenges in spatial scaling
Authors: LODGE DAVID M. , STEIN ROY A. , BROWN KENNETH M. , COVICH ALAN P. , BRÖNMARK CHRISTER , GARVEY JAMES E. , KLOSIEWSKT STEVEN P.
Published: July 2006

Abstract
Global homogenization of biota is underway through worldwide introduction and establishment of nonindigenous (exotic) species. Freshwater ecologists should devote more attention to exotic species for two reasons. First, exotics provide an opportunity to test hypotheses about what characteristics of species or habitats are related to successful establishment or invasibility, respectively. Second, predicting which species will cause large ecological change is an important challenge for natural resource managers. Rigorous statistical relationships linking species characteristics to probability of establishment or of causing ecological impacts are needed. In addition, it is important to know how reliable different sorts of experiments are in guiding predictions. We address this issue with different spatial scales of experiments testing the impact of two predators on native snail assemblages in northern Wisconsin USA lakes: an exotic crayfish, the rusty crayfish (Orconectes rusticus); and a native fish predator, the pumpkinseed sunfish (Lepomis gibossus). For the crayfish, laboratory experiments, a field cage experiment, and a snapshot survey of 21 lakes gave consistent results: the crayfish reduced abundance and species richness of native snails. Laboratory and field experiments suggested that pumpkinseed sunfish should have a similar impact, but the lake survey suggested little impact. Unfortunately, no algorithms exist to guide scaling up from small‐scale experiments to the whole‐lake, long‐term management scale. To protect native biodiversity, management of freshwater exotic species should be targeted on lakes or drainages that are both vulnerable to colonization by an exotic, and that harbour endemic species. Management should focus on preventing introduction because eradication after establishment is usually not possible.
Variation in bradyspory and seedling recruitment without fire among populations ofBanksia serrata(Proteaceae)
Authors: WHELAN R. J. , DE JONG N. H. , VON DER BURG S.
Published: July 2006

AbstractLong‐term canopy storage of seeds in fruits (bradyspory) varies among species and is thought to be related to the fire regime experienced by the plant community. This study sought to quantify intraspecific variation in bradyspory among nine populations ofBanksia serrata(Proteaceae) on the south coast of New South Wales. Marked differences were found between populations, ranging from more than 30% of follicles open at two coastal sites, to less than 5% of follicles open at two inland heath sites. Low levels of bradyspory occurred particularly in coastal sites which also hadBanksia integrifolia, a non‐bradysporous species, present. In addition to spontaneous follicle opening without fire, fall of infructes‐cences to the ground after breaking of branches was observed to be a major contributor to seed release. At three sites where fire had not occurred for many years, the amount of seedling establishment since the last fire corresponded well with levels of bradyspory; there were no inter‐fire recruits at the site with the strongest bradyspory, while at the site with the weakest bradyspory there were numerous inter‐fire plants, some with lignotubers large enough to be able to tolerate the next fire. It is argued that populations ofB. serrataexhibit variable patterns of recruitment, depending on the site characteristics, ranging from complete dependence on fire for population maintenance to bet‐hedging (spreading potential recruitment between fire events and inter‐fire periods). Variations in populations and reproductive characteristics among sites make the application of demographic models to management decisions habitat‐specific.
Richness of species and growth‐forms within sclerophyll and mesophyll vegetation in eastern Australia
Authors: Le Brocque Andrew F.
Published: July 2006

Abstract The patterns in total species richness and in the richness of the dominant growth‐forms of vegetation communities of coastal sclerophyll and mesophyll vegetation in eastern Australia are examined. Plant species richness data were obtained from two 500 m2 quadrats from 50 sites within a single geographical region north of Sydney, New South Wales. Concentrically nested subquadrats within each quadrat enabled the determination of species‐area relationships for total species richness and its components. Three growth‐forms were examined (trees, shrubs and ground cover) and patterns in the richness of these components were compared to those exhibited by total species richness. Total species richness was higher in sclerophyll communities on Hawkesbury Sandstone soils than in adjacent mesophyll communities on Narrabeen shales and sandstones. Significant patterns in total species richness within the two soil types were also found. Shrub and ground cover species richness showed strong correlations with total species richness, with higher richness in the sclerophyll communities. However, tree species richness contributed little to the patterns in total species richness. The results of this study suggest that differential patterns in the components of total species richness must be taken into account for effective modelling of natural areas based on species richness and diversity parameters.
The influence of flock size and geometry on the scanning behaviour of spotted turtle doves, Streptopelia chinensis
Authors: SADEDIN SUZANNE R. , ELGAR MARK A.
Published: July 2006

Abstract The negative correlation between the time individuals spend scanning the environment for predators and group size is usually explained by the benefit of corporate vigilance. However, this negative correlation may be explained additionally in terms of the ‘dilution effect’ and ‘selfish herd geometry’. Our experimental investigation of the scanning behaviour of free‐living spotted turtle doves foraging at different shaped feeders revealed that flock geometry influenced individual scanning rates. The time spent scanning declined with group size less rapidly among birds foraging in linear flocks than among those foraging in more two‐dimensional flocks. These results were not confounded by aggressive behaviour, and indicate that the benefits of foraging in groups include the so‐called selfish herd geometry.
Appropriate spatial scales for studies of reef‐fish ecology
Authors: SALE PETER F.
Published: July 2006

Abstract Coral‐reef systems are conspicuously multi‐scalar, with scales set by reef‐fish biology, by ecological processes that act upon them and by the architectural patchiness of the coral‐reef environment in which they reside. Empirical ecological studies cannot be executed in a way that is independent of spatial scale, and results are inextricably scale‐dependent. Further, although the question asked and the measurements planned will suggest appropriate scales, it is often the case in these multi‐scalar systems that there is no single correct scale at which to sample. Instead, there must be a process of compromise in designing projects, an awareness of scale in implementing them and careful consideration of the scale‐dependence of the results. Some useful principles are presented to help with the process of project design and interpretation.
Age‐specific mortality rates in reef fishes: Evidence and implications
Authors: CALEY M. J.
Published: July 2006

AbstractMortality is a fundamental demographic rate, the nature of which has profound consequences for both the dynamics of populations and the life‐history evolution of species. For example, if per capita mortality rates are age‐ or stage‐specific, life‐history traits should evolve in response to age‐ and stage‐specific differences in selection arising from these temporally variable rates. Similarly, variation in the average mortality rate across ages and/or stages can also select for shifts in life history. Mortality rates of recently settled reef fishes can be very high and per capita mortality is commonly assumed to decrease with increasing age. A review of evidence for age‐specific per capita mortality rates in reef fishes from early postsettlement up to 13 months postsettlement suggests that during this period these rates are often age invariant. The data on which these interpretations are based, however, are extremely limited both in terms of the proportion of the life cycle over which mortality rates have been sampled and the quality of these data. Nonetheless, these data do suggest that selective pressures associated with patterns of mortality may vary among species of reef fishes and that these species therefore could be more effectively used in the study of life‐history evolution. At present, reef fishes are under‐represented in the study of life‐history evolution compared with other vertebrate taxa.
Disturbance, habitat structure and the ecology of fishes on coral reefs
Authors: JONES G. P. , SYMS C.
Published: July 2006

Abstract This paper reviews empirical studies relating communities of coral‐reef fishes to the characteristics of the underlying habitat, and the effects of habitat disturbance. Many contrasting patterns in the relationships between fish communities and coral cover, habitat heterogeneity or topographic complexity have been described, including strong effects of particular habitat characteristics (both positive and negative), as well as those finding weak or no relationships. In addition, a whole range of potential responses to different kinds of disturbance, including hurricane damage, crown‐of‐thorns (Acanthaster planci) outbreaks, and El Niño‐associated coral and sea urchin die‐offs, have been described. Few workers have attempted to test among alternative models about the importance of resource limitation or responses to disturbance, so critical hypotheses have not been tested. Potential generalizations may be obscured due to a number of problems faced when making comparisons among existing studies. These include the enormous variation in the magnitude of changes to habitats observed, restrictive assumptions about the form of relationships between fish and habitat variables, inadequate descriptions of habitat and fish community structure, a heavy reliance on ‘natural’, pseudoreplicated experiments and a plethora of different numerical and analytical techniques. We conclude that the search for generalizations would be facilitated by a greater attention to theory and clearer statements of the hypotheses being tested. Evaluation of the general importance of fish‐habitat interactions must await the application of common observational and experimental methodologies to a wider range of fish taxa and locations.
Application of marine reserves to reef fisheries management
Authors: BOHNSACK JAMES A.
Published: July 2006

Abstract Establishing permanent ‘no‐take’ marine reserves, areas where fishing and all other extractive activities are prohibited, is an attractive but under‐utilized tool for fisheries management. Marine reserves could potentially deal with many fishery problems that are not effectively addressed by other traditional management measures; they also offer numerous social, economic, and scientific benefits not directly related to fisheries. Limited but growing research has shown beneficial biological and economic effects of marine reserves on fisheries. More research is needed, especially at larger scales, to determine the ideal marine reserve size, number and location necessary to optimize fisheries productivity and resource conservation. Sufficient evidence is available to justify the expanded use of marine reserves in an adaptive approach to fisheries management.
Does irrigation affect leaf phenology in deciduous and evergreen trees of the savannas of northern Australia?
Authors: MYERS B. A. , WILLIAMS R. J. , FORDYCE I. , DUFF G. A. , EAMUS D.
Published: July 2006

Abstract Soil moisture was augmented experimentally during two successive dry seasons and the intervening wet season in a humid tropical savanna in Darwin, northern Australia. Leaf phenology was monitored in four common tree species Termmalia ferdinandiana and Planchonia careya (both deciduous species), and Eucalyptus miniata and Eucalyptus tetrodonta (both evergreen species). Irrigation produced consistently significant effects in only T. ferdinandiana. In this species leaf‐flush was significantly earlier, canopy decline and leaf‐fall were significantly later and the attainment of full canopy was earlier in irrigated compared with non‐irrigated trees. Litterfall, and the seasonal patterns of contraction and expansion of stems (a measure of stem water status or storage) were not significantly affected by irrigation in any species. Leaf longevity in the deciduous species was 6–8 months; some eucalypt leaves lived for approximately 1 year, but none lived longer than 18 months. Irrigation had relatively little effect on leaf longevity. While variation in soil moisture is a potentially important cue to both leaf‐fall and leaf‐flush, stem water status and climatic factors such as vapour pressure deficit may also be important climatic cues to phenological behaviour.
A surplus of seeds: High rates of post‐dispersal seed predation in a flooded grassland in monsoonal Australia
Authors: WURM P. A. S.
Published: July 2006

Abstract Oryza meridionalis is an annual emergent wetland grass which produces between 26 and 260 kg seeds ha‐1 annually. Seed shed occurs at the end of the wet season, when the plains are usually still partially flooded. The juvenile recruitment of key native vertebrate species, such as the Magpie Goose (Anseranus semipalmata) and the Dusky Plains Rat (Rattus colletti), coincides with seed shed. This study investigated predation of O. meridionalis seeds at two sites on the South Alligator River floodplain in monsoonal Australia. The effects of inundation and the presence of a background density of seeds on seed removal were investigated by stratified sampling with respect to position down the topographic slope, to include the ‘dry’ floodplain margin, ‘damp’Oryza zone, and ‘flooded’Oryza zone. The effect of seed lot size on the proportion of seed removed was also investigated, and exclosures were used to identify the principal predator group. The proportion of seeds removed was not affected by the presence/absence of a background of seeds nor the number of seeds placed in experimental ‘lots’. The majority of seeds (75%) was consumed by vertebrate predators (most likely the abundant Dusky Plains Rat). Inundation afforded some protection from predation. Despite high losses of seeds exposed to predators, O. meridionalis is an abundant and widespread species on these floodplains, possibly because of the protection from predation afforded by inundation to those seeds which are shed into the water column. It is likely that there is a complex interaction between topography, rainfall and predator and prey relationships, which ultimately determines the importance of seed removal for the maintenance of populations of O. meridionalis. These high losses of seeds to predation have implications for wetland rehabilitation where seed broadcasting is proposed.
Does the recently introduced bumblebee Bombus terrestris (Apidae) threaten Australian ecosystems?
Authors: KINGSTON ANDREW B. , McQUILLAN PETER B.
Published: July 2006

Abstract Native vegetation near Hobart in Tasmania was investigated to determine whether it was being invaded by the recently introduced large earth bumblebee, Bombus terrestris (Linnaeus, 1758). This species was found to be established in high numbers in a variety of vegetation types from coastal heath, through sclerophyll forest, and subalpine shrubberies up to an altitude of 1100 m. Hence, it has the potential to spread through much of Tasmania and temperate, mesic regions of mainland Australia. It is highly polylectic, foraging on at least 66 native plant species from 21 families. While the most heavily visited species produced abundant nectar, the lack of pre‐dation on this species also allowed it to forage economically on small flowers in clusters. This foraging profile overlapped with those of all anthophilous insect families, all bee subgenera, and all species of nectarivorous birds which were encountered. Therefore, B. terrestris has the potential to compete with most native anthophiles and commercial honeybees. As it forages from some plant taxa which are not visited by the European honeybee, Apis mellifera Linnaeus, 1758, this species is impacting on plant‐pollinator relationships which have previously been free from the effects of exotic bees.