bluuebunny/crossref_metadata_2025 huggingface dataset:
Dieback of rural eucalypts: Response of foliar dietary quality and herbivory to defoliation
Authors: LANDSBERG JILL
Published: July 2006

Rural dieback of Eucalyptus blakelyi trees growing on pastoral properties near Canberra is associated with chronic defoliation by insects. In order to test the effect of defoliation on subsequent herbivory, I artificially defoliated three healthy trees by clipping their terminal branchlets. The foliage that regrew on the clipped trees was nutritionally superior to the foliage it replaced, and was much more heavily damaged by grazing insects. There was a transient increase in the tannin content of the regrowth foliage, but this was apparently ineffective in defending it from subsequent herbivory. Compared with the foliage on nearby E. blakelyi trees that also produced major flushes of leaf growth during the same period, the regrowth on the clipped trees had enhanced dietary qualities and suffered more insect damage. Leaf age contributed to many of the differences in dietary quality, but when adjustments were made for the effects of leaf age the same trends remained. Five of the nearby trees were suffering from the chronic insect grazing associated with rural dieback, and the other five appeared healthy. The dietary quality of regrowth foliage on the clipped trees was qualitatively more similar to that of foliage on the dieback trees. Thus the chronic herbivory associated with rural dieback may be partly self‐perpetuating, given this positive feedback between defoliation and dietary quality, and an apparent absence of other effective controls on insect populations.
An analysis of density responses of forest and woodland birds to composite physiognomic variables
Authors: MACNALLY RALPH C.
Published: July 2006

Habitat ordinations were performed on 37 sites in forests and woodlands along a latitudinal transect that spanned over 250 km in central Victoria. Australia. Multivariate analyses of these data by using nonmetric. multidimensional scaling (AIDS) were used to generate composite variables. The relationships of these composite variables and densities (by area) of 58 species of forest and woodland birds were assessed by using linear and polynomial regressions. Only seven of the 58 species of birds did not display a significant relationship to one or other of the five composite variables. Approximately 50% of the avian species showed significant relationships with each of the first two composite variables, but lower percentages were observed for the other three variables. About a third of all significant correlations were either of second or third order, ft appears that marked curvilinearities associated with the first composite variable can be interpreted as linear responses with respect to the secondary composite variable. These results suggest that, although composite variables derived from multivariate classifications are statistically independent, there often may be substantial biological dependence between the composite variables. Therefore, for biological interpretation, it would be appropriate to regard composite variables derived from multivariate classifications as suites of related variables. Some authors have traced sharp discontinuities in distributions of species with respect to habitat structure by using presence/absence data alone. This approach appears to be sensitive to sampling of habitat types, and densities should be used wherever possible.
Bioclimatic analysis of the distribution of damage to native plants in Tasmania by Phytophthora cinnamomi
Authors: PODGER F. D. , MUMMERY D. C. , PALZER C. R. , BROWN M. J.
Published: July 2006

Climatic profiles were generated by the computer program BIOCLIM for three sets of sites in native vegetation in Tasmania: (i) 308 sites at which Phytophthora cinnamomi was isolated from diseased plants Pc+ ive; (ii) 322 sites in healthy plant communities from which P. cinnamomi could not be recovered Pc−ive; and (iii) 801 sites representing the climatic range across Tasmania. A discriminatory analysis comparing the first and third sets indicated that seven of the 16 climatic indices available for analysis were good discriminators of the distribution of damage by P. cinnamomi. The analysis suggests that damage to native vegetation due to P. cinnamomi is unlikely on sites where annual mean temperature does not exceed 7.5°C or annual mean rainfall is < 600 mm. Two maps were produced to indicate those areas of Tasmania that have climates suited to damaging interaction between P. cinnamomi and native vegetation. The first was based on those sites that had annual mean temperature more than 7.5°C and annual mean rainfall less than 600 mm. The second included those sites that matched the values of the Pc+ ive set for all seven good discriminators. The two approaches produced similar results. Areas in which even the most favourable microsites are unlikely to support pathogenic activity by P. cinnamomi constitute less than 20% of the land area. Twelve substantial areas of native vegetation that occur in climates suited to infection by P. cinnamomi. but for which no record of the fungus exists, have been identified.
Evidence of late Pleistocene fires and eucalypt forest from a North Queensland humid tropical rainforest site
Authors: HOPKINS M. S. , GRAHAM A. W. , HEWETT R. , ASH J. , HEAD J.
Published: July 2006

Charcoal fragments, some identified as Eucalyptus, with radiocarbon dates spanning the period 27 000–12 000 years bp, were found in a soil profile under moist tropical rainforest in north‐eastern Australia. The charcoal indicates that sclerophyll forest occupied a central part of the Windsor Tableland rainforest massif during the late Pleistocene. The widespread presence of identifiable and dateable charcoal under rainforest in north Queensland provides an opportunity to examine the patterns and ecological implications of fluctuations in rainforest distribution in recent history.
Ecology of sessile animals on sublittoral hard substrata: The need to measure variation
Authors: BUTLER A. J. , CHESSON P. L.
Published: July 2006

This paper concerns assemblages of sessile animals occupying shaded, commonly vertical hard substrata in the shallow subtidal zone. We are interested particularly in questions about the coexistence of species and about what influences their joint dynamics. We propose a conceptual model which focuses on variation in characteristics such as birth and death rates, competitive interactions and dispersal.

We argue that, qualitatively, this model appears to be a satisfactory representation of the important characteristics of certain sessile assemblages. Further, we suggest that it may explain the coexistence of a large number of ecologically similar species in assemblages that appear in a sense ‘stable’ (but where assemblages at different sites differ in detail). There is support for this assertion from formal theoretical work on simpler versions of the model.

It is not sufficient merely to argue that the model seems satisfactory or plausible, so we finally consider what kind of data is needed for the further development and testing of this kind of model.
Mutualistic interdependence between mistletoes (Amyema quandang), and spiny‐cheeked honeyeaters and mistletoebirds in an arid woodland
Authors: REID NICK
Published: July 2006

The mutualism involving mistletoes (Amyema quandangj, spiny‐cheeked honeyeaters (Acan‐thagenys rufogularis) and mistletoebirds (Dicaeum hirundinaceum) was studied in arid woodland in South Australia between 1980 and 1984. Plants and birds were locally interdependent: mistletoes supplied a continuous resource of fruits or nectar that sustained permanent populations of pollinators (honeyeaters) and dispersers (honeyeaters and mistletoebirds). The reproductive phenology of Amyema quandang was central to the interactions. Amyema quandang flowered in winter and annual fruit crops overlapped so that ripe fruit was continuously available. Spiny‐cheeked honeyeaters obtained most of their energy requirements from mistletoe nectar in winter and mistletoe fruit in summer. Higher honeyeater densities were sustained by flowering in winter. Mistletoebirds were present in low density throughout the year and subsisted on a diet of mistletoe fruit and a few insects.

The reproductive strategy of A. quandang probably evolved in response to the pollination and dispersal service provided by honeyeaters in inland Australia. Neither spiny‐cheeked honeyeaters nor mistletoebirds have adaptations resulting from evolutionary interactions with A. quandang. The high specificity of their mutualism is a result of: (i) the abundance of A. quandang in relation to other nectar and fruit producing plants in the community: (ii) the year‐round production by A. quandang of the primary source of fruit or nectar for honeyeaters and mistletoebirds: (iii) the facultative specialization of both birds on A. quandang; and (iv) the reluctance or inability of other frugivorous birds in the community to consume A. quandang fruit.
Habitat selection in the White‐plumed Honeyeater and the Fuscous Honeyeater at an area of sympatry
Authors: CHAN K.
Published: July 2006

Multivariate analysis on 15 habitat variables and quantitative data on foraging and interactive behaviour were used to investigate habitat selection in the White‐plumed Honeyeater (Lichenostomus penicillatus) and the Fuscous Honeyeater (Lichenostomus fuscus) at an area of sympatry in woodland in New England Tablelands. Thirty‐nine plots from four sites were used to examine significant differences in habitat utilization during the breeding period. The White‐plumed Honeyeater associated strongly with narrow belts of riverine Casuarina while the Fuscous Honeyeater was associated with Eucalyptus in the extensive eucalypt woodland. The narrow ecotone was used by both species, but the two occurred together only in an extremely narrow zone. Changes in foraging activities were observed between this overlap zone and non‐overlap zone. Both niche breadth and overlap in relation to four measures of foraging were reduced in plots where species were in joint occurrence compared with where they were not, although overlap in most measures of foraging remained high. The number of encounters between the two highly aggressive and abundant species was not great. Thus, the species appear generally to avoid each other. The observed spacing pattern may result from prior experience of intense aggressive interactions. Distinct habitat features could provide easily recognized cues for the maintenance of local horizontal separation. Other factors such as slight differences in morphology, habitat preference, foraging and physiology may enhance differences in habitat selection.
Habitat peculiarity as a cause of rarity in Eucalyptus paliformis
Authors: PROBER SUZANNE M. , AUSTIN M. P.
Published: July 2006

Eucalyptus paliformis is a rare species of the Wadbilliga Plateau in southeastern Australia. The hypothesis that rarity in E. paliformis is a result of restriction to a rare habitat was addressed by means of a floristic survey comparing sites where E. paliformis occurs with similar sites where it is not known to occur. Mathematical models describing mean annual rainfall and mean annual temperature regimens experienced in southeastern Australia were used to locate areas with a climate similar to E. paliformis sites. Understorey vegetation of E. paliformis sites was then compared with that of climatically similar areas using a stratified random sampling procedure. Similarity in floristic composition was used as an integrated measure of habitat similarity. Detrended correspondence analysis of the floristic data suggested that E. paliformis sites are unique. No single environmental factor was sufficient to describe E. paliformis sites—rather, their peculiarity could be ascribed to a unique combination of environmental factors. Within the Wadbilliga area, temperature or moisture parameters relating to marginally higher elevation or low relative radiation index may be important. Non‐metric multidimensional scaling of the floristic data revealed similar environmental trends in the data, but support for habitat peculiarity in E. paliformis was weaker.
Ecological association of habitats and bird species during the breeding season in southeastern New South Wales
Authors: RECHER H. F. , KAVANAGH R. P. , SHIELDS J. M. , LIND P.
Published: July 2006

Bird communities in southeastern New South Wales, as determined by classification and ordination techniques, were seldom discrete. The most cohesive assemblage was associated with wet sclerophyll and rainforest habitats. These moist forests also supported the richest avifaunas and had high population densities. Although most birds occurred throughout the region, most species were uncommon. Of the 116 species recorded, 51 (44%) were found on fewer than 10% of the 143 plots censused. Only 19 species occurred on more than half the plots, with six of these recorded on more than 90% of the plots. Other than a small group of birds primarily restricted to moist forest, only the most common and widely distributed species regularly occurred together. Species were grouped with habitats on an elevational gradient from coastal forests to the tablelands. Within this elevational range, species were associated with major structural features of the vegetation. In terms of bird assemblages, open habitats were distinguished from those with dense vegetation. Plots which had been recently logged were separated from mature forest. The results indicate that plans for wildlife management should consider both the assemblages of species which are associated with major forest habitats and the requirements of individual species.
Assessing the effects of fire on vegetation in tropical savannas
Authors: LONSDALE W. M. , BRAITHWAITE* R. W.
Published: July 2006

Because of its high frequency and generally low intensity, fire in tropical savannas appears to be a different phenomenon from that in other biomes. A recent study of fire in savanna at Munmarlary in northern Australia, analysed by detrended correspondence analysis (DCA) concluded that different fire regimens resulted in negligible changes in the vegetation, a conclusion crucial for fire management in the region.

Here, we describe the short‐term impact of an unusually intense fire in an area of tropical open forest. Tree and shrub mortality of 14.3% was recorded within 6 months of the fire, and the composition of the vegetation was changed because of differences between species in mortality rates, which ranged from 4 to 90%. Analyses of variance (ANOVA) of DCA co‐ordinates were unable to detect any change, however. DCA seems inappropriate for analysing vegetation changes after savanna fires, because the floristic changes, compared with those in temperate fire‐prone ecosystems, are subtle and multidirectional.

Further, it is shown that rather large plot sizes (2–4 ha) are likely to be required to detect fire treatment differences even as great as about 20% of the mean, given the variability of savanna vegetation, and replicates that are likely to be limited in number. A possible solution is to measure the change over time in permanent plots, rather than attempting to detect treatment differences by sampling on a single occasion.
An evaluation of hypotheses to explain the pattern of sap feeding by the yellow‐bellied glider, Petaurus australis
Authors: GOLDINGAY ROSS L.
Published: July 2006

Yellow‐bellied gliders on occasion extensively incise the trunks of eucalypts to feed on sap but in doing so show strong preference for the species and number of trees utilized. Three hypotheses that may account for aspects of this behaviour were examined. They were: (i) sap feeding is related to the incidence of rain; (ii) sap feeding is influenced by the sap flow idiosyncracies of trees; and (iii) sap feeding is influenced by the availability of alternative food resources. Sap feeding at two sites occurred independent of ‘wet’ or ‘dry’ nights. Sap flow (measured as an index) in two species of eucalypt was highly variable among trees and among sample periods. This is the only hypothesis that accounts for the selectivity of the trees incised. Sap feeding at one site coincided with periods of high sap flow. However, at another site, sap feeding did not occur on measured trees despite their often high sap flow. At such times, flowering trees were abundant and gliders fed extensively on nectar. Thus, elevated sap flow may provide the necessary precondition conducive for sap feeding but may be ignored when other food types are available.
A matrix population model analysis for the tropical tree, Araucaria cunninghamii
Authors: ENRIGHT N. J. , WATSON A. D.
Published: July 2006

The temporal stability of estimates of demographic behaviour for a sample population of the tropical rainforest gymnosperm Araucaria cunninghamii was analysed using a stage‐classified (Lefkovitch) matrix model. Previously published life‐table analyses, which used only 2 years of held data (1975–77), were compared with life‐table analysis based on a further 5 years of field data for growth and survival (1977–82). The new analysis calculated the finite rate of natural increase, λ, as 1.009 ± 0.077. This value is closer to the theoretical value of 1.0 for a stable population than is the value calculated on the basis of only 2 years of field data (1.021 ± 0.093). However, the two estimates are not significantly different from each other or from a value of 1.0.

Despite the similarity of estimates for λ, the life‐table analysis based on 5 years of data showed some marked differences from the earlier analysis. Revised growth and survival rates imply a slower progression to reproductive maturity and shorter reproductive life for A. cunninghamii. The predicted stable stage distribution (SSD) showed a better fit to the initial stage distribution (ISD), and bulges in the frequency distribution for large trees can be explained by the varying rates at which individuals grow from one stage to the next.

The relative contributions of survival, growth and fecundity to the observed population growth rate (elasticity) remained similar for both analyses. Survival rate contributes most significantly to the achieved population growth rate, and this appears typical of long‐lived plant species. However, the pattern of elasticities across size‐classes changed for the new analysis and identified different critical life history stages from those recorded previously.

Elasticity is proposed as a measure for classifying species using the competitive (C), stress‐tolerant (S) and ruderal (R) model of plant strategies.
Responses of litter arthropods to major natural or artificial ecological disturbances in mountain ash forest
Authors: NEUMANN FREDERICK G.
Published: July 2006

Pitfall trapping was used in commercial Mountain Ash (Eucalyptus regnans) regrowth forest to study the effects on epigeal arthropods of high‐intensity wildfire plus salvage logging, and of harvesting by clearfelling plus slash burning, followed by fire‐induced natural or artificially established regeneration respectively. The study, the first of its kind in the Victorian Central Highlands, 60 km east of Melbourne, was based on 146 922 specimens of 30 ordinal or lower level taxa collected over a 3‐year period. The abrupt replacement of the ecologically complex regrowth forest by ecologically much simpler even‐aged regeneration caused appreciable instability among the litter‐frequenting arthropods. An immediate decline in diversity occurred due to short‐term boosts in activity of some common ‘major’ taxa (notably a species of seed‐harvesting ant) and the suppression of other taxa. A broad mix of functionally diverse taxa reappeared within two years of regeneration, and all but three rarely trapped ‘minor’ taxa present in undisturbed 43–46 year old regrowth (‘control’) forest had returned within 5 years. Epigeal arthropods therefore appeared to be affected only over a short period relative to the nominal 80–150 year rotation of the E. regnans ecosystem. Research is needed at the species level to achieve a more precise assessment of arthropod responses to major ecological disturbances.
Problems with measuring diet selection of terrestrial, mammalian herbivores
Authors: NORBURY G. L. , SANSON G. D.
Published: July 2006

Abstract
The validity of methods used to measure diet selection has often been overlooked. This paper examines problems associated with the scale of food availability, perception of food by animals, measures of dietary composition, measures of food availability and diet selection indices. Most problems can be reduced by the choice of techniques consistent with the objective and degree of accuracy required, both of which should be clearly stated. In particular, the measured sample of food utilized by the animal should be spatially and temporally matched to the scale of food availability under consideration. In the past, researchers have tended to overstate the accuracy of their results. We support the view that the most appropriate analysis of diet selection is ranking food items in order of selection according to the value of the selection index.
Preliminary observations on the distribution and abundance of seaweed flies (Diptera: Coelopidae) on beaches in the Gosford district of New South Wales, Australia
Authors: BLANCHE K. R.
Published: July 2006

Abstract
Thirteen species of the family Coelopidae occur in beach wrack on Australian coasts, predominantly at temperate latitudes. Four species (This canus, Chaetocoelopa sydneyensis (Schin.), Amma blancheae and Dasycoelopa australis Mall.) can be caught on beaches in the Gosford district, New South Wales. Seasonal changes in the distribution of coelopid species may be linked with seasonal weather variations. Field and laboratory data on the commonest and most abundant species, T. canus, suggest that variations in adult abundance could be due to fluctuations in high tide level governing the rate of the coelopid life cycle. Local weather conditions and human influences may modify the effects of the high tides.
The arthropod community of an Australian rainforest tree: Abundance of component taxa, species richness and guild structure
Authors: BASSET Y. , Arthington A. H.
Published: July 2006

Abstract
The arthropod community within the crowns of Argyrodendron actmophyllum (Sterculiaceae) in a subtropical rainforest near Brisbane, Australia, was investigated during a 2 year study using interception traps and restricted canopy fogging. The total arthropod density was 34 individuals m−2 of leaf area. Spiders, psyllids, thrips, psocids and chrysomelids were most abundant. The most diverse families included Curculionidae, Cicadellidae, Staphylin‐idae, Cerambycidae, Theridiidae, and Chrysomelidae. The arboreal community of A. actinophyllum exhibited several features common to arthropod communities from temperate and tropical rainforest trees. Affinity with temperate trees was suggested by the relatively high densities of certain species, by high proportions (in terms of individuals) of sap‐suckers and non‐insect predators, and by a low proportion of ants. Affinity with tropical rainforest trees was expressed by high proportions of scavenging fauna, particularly wood‐eaters and fungalfeeders.
Survival of saltbush (Atriplex vesicaria) seedlings in heavily grazed experimental plots
Authors: LANGE R. T. , Coleman D. , COWLEY K. R.
Published: July 2006

Abstract
A grazing experiment in mixed chenopod shrubland near Whyalla, South Australia, is reported, in which the survivorship probabilities of saltbush shoots were measured, contrasting isolated (small seedling) shoots with equivalent shoots in outermost adult plant foliage.

Throughout the experiment, measurements showed that seedlings were spared relative to shoots of adult plants. This is in agreement with visual assessments from numerous earlier experiments. When the experiment was terminated, adult root survivorship was 0.035 whereas seedling survivorship was 0.49. This outcome is discussed.
Predispersal mortality and fecundity in the grey mangrove (Avicennia marina) in southeastern Australia
Authors: CLARKE P. J.
Published: July 2006

Abstract
The predispersal mortality of floral buds and fruits in the grey mangrove (Avicennia marina) was examined over a range of populations for 3 years. The average survival of floral buds to anthesis was 34%. Moth larvae (subtribe Phycitina) attack and consume the contents of variable numbers of flower buds, but their activities did not influence bud survival, as experimental exclusion of larvae did not increase the number of buds surviving to anthesis. Fruit mortality is initially high with an average of 21% of floral buds surviving to immature fruit. Subsequent mortality is lower until on average 2.9% of floral buds survive to become viable propagules. Several cohorts of the phycitine moth larvae feed throughout the development of the fruit, and up to 62% of mature fruit show signs of larval attack. Experimental exclusion of moth larvae doubled the survival of fruits. However more than 75% of fruit mortality may be attributed to maternal regulation. Hail storms can also cause fruit mortality. The potential fecundity (number of ovules) of A. marina was measured over a range of age‐size classes of trees and the realized fecundity (viable propagules) was estimated from average predispersal mortality. These estimates were subsequently verified in the field. A fecundity schedule was constructed with assumptions on reproductive frequency and reproductive life. The average annual supply of propagules over a lifetime is estimated to be about 247 viable propagules per tree.
Multivariate pattern analysis of wetland invertebrate communities and environmental variables in Western Australia
Authors: CROWNS J. E. , Davis J. A. , CHEAL F. , Schmidt L. G. , ROSICH R. S. , Bradley S. J.
Published: July 2006

Abstract
Macro‐invertebrates, zooplankton and water quality variables were sampled at 33 wetlands near Perth, Western Australia, in January‐February 1989. Wetlands were classified and ordinated using the invertebrate data. Correlations of environmental variables with the ordination were calculated and the importance of seasonality and geomorphology of the wetlands were investigated. The wetlands were also classified and ordinated using the chemical data. Analysis of variance was used to compare species richness, abundances of all invertebrates, macro‐invertebrates, copepods and total phosphorus levels among groups. Six groups of wetlands were identified from the invertebrate data, two of which were outliers on the basis of very low pH and high salinity, respectively. The majority of the wetlands grouped on the basis of their degree of nutrient enrichment and colour. The analyses of chemical data gave similar groups. The coloured wetlands and least nutrient enriched non‐coloured wetlands were identified as being closest to the probable state of wetlands prior to European settlement. The greatest numbers of rare species were found in wetlands from these two groups. Species richness was significantly higher in the moderately enriched wetlands than in any other group but decreased in the most enriched wetlands where abundances of invertebrates were highest. Changes in community composition among the groups of wetlands are discussed. The most highly nutrient enriched wetlands were dominated by cosmopolitan species with high abundances, whereas less enriched and coloured wetlands had species with more restricted distributions and lower abundances.
Biogeography of grasses (Poaceae) on islands of southwestern Australia
Authors: ABBOTT I.
Published: July 2006

Abstract
The number of native grass species and exotic grass species present on 129 offshore islands of southwestern Australia is best predicted by island area and island disturbance, respectively. Isolation of islands and gull activity on islands only slightly improved these predictions. Species turnover on a subset of 30 islands indicated that exotic grass species were more prone to local extinction and more likely to immigrate than native grass species. The major conservation implication of this study is that habitat disturbance on these islands should be minimized to reduce establishment of exotic grass species.
Variation in foliar nutrients in Eucalyptus trees in eastern and Western Australia
Authors: MAJER J. D. , Recher H. F. , GANESHANANDAM S.
Published: July 2006

Abstract
Levels of nitrogen, phosphorus and potassium were measured for the foliage of two co‐dominant eucalypts at each of two sites, one in eastern Australia and the other in Western Australia. In eastern Australia, foliage was sampled in the canopy and subcanopy for narrow‐leaved ironbark Eucalyptus crebra and grey box E. mollucana and in Western Australia, for jarrah E. marginata and marri E. calophylla. The Western Australian trees were also sampled for ‘young’ and ‘old’ leaves. Both eucalypts in eastern Australia had greater nitrogen and phosphorus levels, but lower potassium, than E. marginata or E. calophylla. Eucalyptus calophylla foliage had greater levels of all three nutrients than E. marginata foliage as did E. crebra relative to E. mollucana. At both sites, foliar nutrient levels were greater in the canopy than subcanopy foliage, and, at least in Western Australia, the younger leaves had greater nutrient levels than the older leaves. The observed differences in foliar nutrient levels are consistent with observed trends in the abundance and diversity of foliage arthropods and the use of the trees as foraging substrates by birds.
The effects of sheep‐grazing on the subterranean termite fauna (Isoptera) of the Western Australian wheatbelt
Authors: ABENSPERG‐TRAUN M.
Published: July 2006

Abstract
The majority of existing remnants of wandoo Eucalyptus capillosa woodland in the Western Australian wheatbelt have been grazed by sheep for several decades and are often visibly degraded. A pilot survey was conducted into the effects of sheep on vegetation and soil variables, and the abundance, diversity and species frequency of occurrence of subterranean termite communities. Ten 1/4 ha study plots were used for paired grazed/ungrazed comparisons. Ungrazed plots had more litter mass (dry weight), leaf and woody litter, canopy cover (%) and soil moisture (moisture content <1.2% across study plots); grazed plots had a higher percentage of bare ground. Termites were as abundant, and as diverse, in grazed as in ungrazed plots, and were equally often sampled in the soil and surface wood. Termite species eating sound wood, decayed wood/debris and grass were sampled equally often, and were of equal diversity in sheep‐grazed as in ungrazed plots. The mounds of Drepanotermes tamminensis were more abundant in grazed plots. These findings indicate that prolonged sheep grazing in remnants of wandoo woodland of the Western Australian wheatbelt has had no detrimental or beneficial effect on its subterranean termites.
Daylight spectra (400–740 nm) beneath sunny, blue skies in Tasmania, and the effect of a forest canopy
Authors: OLESEN T.
Published: July 2006

Abstract
The photosynthetically active radiation (PAR) incident on a horizontal surface at an open mountain site is positively correlated with solar altitude for sunny, blue sky conditions. The proportion of red light in PAR decreases with increasing solar altitude, while that of blue increases. These results are consistent with the wavelength dependency of Rayleigh and Mie scattering. The ratio of near infrared radiation to PAR decreases with increasing solar altitude towards solar noon and with decreasing solar altitude towards sunset. Thus surface reflection seems to be an important part of the light climate. The relative transmission of daylight through a forest canopy to a horizontal surface is not correlated with solar altitude for sunny, blue sky conditions at a mountain site. The amount of diffuse daylight is negatively correlated with per cent canopy interception, and the amount of direct sunlight is negatively correlated with per cent solar track interception. Daylength is negatively correlated with both canopy and solar track interceptions. The proportion of red light in PAR increases with increasing solar altitude, while that of blue decreases. These results are opposite those for the open site and are due to the spatial patterns of canopy obstruction of the sky vault, and of the spectral quality of daylight across the sky. The ratio of near infrared radiation to PAR in shadelight increases with increasing canopy interception due to the selective scattering properties of the canopy. The ratio for shadelight is positively correlated with the ratio for sunflecks.
Improvement of environmental impact analysis by application of principles derived from manipulative ecology: Lessons from coastal marine case histories
Authors: PETERSON C. H.
Published: July 2006

Abstract
I discuss briefly how the basic science of ecology contributed to the resolution of environmental problems in eight different cases in which I have been involved over the past few years. I then draw from 2 decades of experience as an academic marine ecologist and biological oceanographer to extract general lessons from each case on how environmental applications could be improved by better use of the wisdom of the field of ecology. The eight cases respresent four pairs of contrasts covering a spectrum of applications of ecological science to environmental problems: (i) two assessments of the environmental impacts from coastal ocean discharges, one evaluated by data collected under traditionally designed, self‐monitoring programmes largely mandated by the agency granting the discharge permit and the other employing an academically designed programme of explicit impact testing; (ii) two assessments of the effects of offshore oil and gas development, one done before exploration drilling to assess the adequacy of available environmental information on which to base decisions about drilling permits and the other an analysis of natural resource damages after a coastal oil spill had occurred; (iii) two evaluations of environmental problems conducted by special ad hoc panels created to resolve the environmental disputes; and (iv) two examples of how rule‐making commissions employed ecological insights in the establishment of regulations, in one case to preserve environmental quality and in the other to manage natural fishery resources.

From the experience of these eight cases, I derive 38 lessons for the future improvement of environmental problem solving by better use of ecological sciences. These lessons fall into four categories: (i) improvements in study design and analysis; (ii) recognition of the importance of the multi‐species, multi‐factor (‘ecosystem’) context in which populations are nested; (iii) acknowledgement of how social concerns constrain environmental decisions; and (iv) identification of common fallacies in environmental assessment.
Dynamic models and large scale field experiments in environmental impact assessment and management
Authors: WALTERS C. J.
Published: July 2006

Abstract
Dynamic numerical models and field experiments play important roles in impact assessment and management. Unfortunately, extreme and simplistic views have developed about whether and how to use these tools, so their complementary values to the manager are often not recognized. We often hear the outrageous claim (or hope) that numerical models can synthesize ‘all’ relevant information for predicting the impact of policy choice, hence making experimental experience unnecessary. From experimentalists, we hear the equally naive criticism that ecological systems are so complex that nothing is predictable without experimental experience. What we usually get from the proponents of these extremes are either models that are dangerously unreliable, or experiments that provide nice scientific answers to the wrong questions. Wise use of modelling begins with the following points: (i) explicit modelling is an excellent way to clarify policy concerns and identify processes that are most likely to be important in making predictions about policy effects; (ii) we can do a very good job of modelling some processes and relationships, particularly those having to do with basic spatial and temporal scales of impact as related to physical transport, chemical transformations, and life history characteristics of indicator populations (longevity, delays and response times due to age structured rates of reproduction and mortality); and (iii) there are some important dynamic processes, such as long‐term accumulation of toxic materials in the environment, that unfold over such large space and time scales as to preclude direct experimental study (leaving only the issue of which models to use in making predictions, not whether to model ‐ unless the processes are simply ignored). But points (i) and (ii) represent steps that a good experimentalist will take anyway: be clear about what practical results an experiment is intended to produce, and do not waste effort on experiments to measure things that can be predicted reliably from existing knowledge. The key to successful use of modelling and experimentation in management is in making good judgements about the interface between points (ii) and (iii); that is, in making good judgements about both what variables cannot be reliably predicted, and of these, which to treat experimentally and which to gamble on predicting from models.
Genetic diversity in an ant‐dispersed chenopod Sclerolaena diacantha
Authors: PEAKALL R. , OLIVER I. , TURNBULL C. L. , BEATTIE A. J.
Published: July 2006

Abstract
Sclerolaena diacantha is a common and widespread, short‐lived chenopod of arid Australia. The diaspore contains a food mass attractive to ants and, at sites where the ant Rhytidoponera sp B is common, thousands of diaspores accumulate on the nest mounds. Bagged plants set seed, showing that it is self‐compatible. Population genetic variation was investigated at two levels: within and between sites, and within and between seed banks accumulated on the ant nests. Electrophoretic analysis of adult plants for 17 loci at 12 sites revealed nine polymorphic loci, but within sites only 6–18% of the loci were polymorphic. The values for mean gene diversity (He = 0.042) and total genetic diversity, (HT= 0.088) were lower than those recorded for most other plant species. The mean fixation index of 0.52 indicated a mixed mating system with about 70% selfing. Most of the genetic diversity was distributed within sites (Dst = 0.008) and the mean value of 0.094 for GST indicated low levels of genetic differentiation. Electrophoretic analysis of seeds from 12 ant mounds at two sites showed that genetic differentiation was three times greater between seed banks than between the sites. However, collectively the genetic diversity stored within ant mounds was similar to the total diversity within the sites. It appears that restricted ant‐dispersal and moderate inbreeding may create a local population structure that is undetected when sampling at a larger scale. Since investigations of genetic patterns on a very local scale are just beginning, there is much to learn about the evolutionary and genetic consequences of different seed flow patterns.
Use of heathland and adjoining forest by honeyeaters: Results of a radiotracking study
Authors: PYKE G. H. , O'CONNOR P. J.
Published: July 2006

Abstract
New Holland (Phylidonyris novaehollandiae) and White‐cheeked (Phylidonyris nigra) Honeyeaters that are resident in heathland during February and March, when there is negligible nectar production in that habitat, are expected to forage for nectar at that time in the adjacent open forest habitat. As nectar production in the heathland increases from then to June, while that in the forest decreases, the proportion of time spent by these birds in the forest should decrease over the same period. Radiotracking revealed that during February the residents did, as expected, spend time feeding on nectar in the forest and more time was spent in the forest in February than in April or June. However, the residents spent time away from the heathland throughout the year and spent more time away in June than in April. The resident honeyeaters spent about 80% of their time on our heathland grid overall. Radiotracking also indicated that there was no sharp distinction in behaviour between residents and other birds because birds that had been resident in the past but were not considered to be so at the time (absent residents), birds that would later be considered resident (future residents) and some birds that were never resident, all spent about half their time on the grid. The area that included 90% of heathland locations, estimated by radiotracking, for P. novaehollandiae and P. nigra averaged 0.48 ha per bird.
Litter inputs to a tropical Australian rainforest stream
Authors: BENSON L. J. , PEARSON R. G.
Published: July 2006

Abstract
Vertical litterfall and lateral litter movement were monitored in the riparian zone of Birthday Creek, a small upland rainforest stream in north Queensland, from June 1987 to May 1990. Total litterfall (mean = 484 g m−2 year‐1) was low in comparison with other tropical sites both within Australia and elsewhere. Litterfall was distinctly seasonal, with maxima occurring in the spring (October‐November) and minima in winter (June–July). Tropical storms caused short‐term increases in litterfall, especially of the small wood fraction. Overall, laterally transported litter contributed 6.8% of the total litter input to the monitored section of the stream. Lateral movement varied according to bank slope and microtopographic features and was not related to wind. Nitrogen and phosphorus concentration of leaves were low (mean N= 1.26%, P = 0.029% by weight). Nitrogen concentration of laterally transported levels overall was about 19% higher than that of leaves falling directly into the stream.
Threats to monsoon rainforest habitat in northern Australia: The case of Ptychosperma bleeseri Burret (Arecaceae)
Authors: BARROW PIERS , DUFF GORDON , LIDDLE DAVE , RUSSELL‐SMITH JEREMY
Published: July 2006

Abstract
Rainforest patches in the Australian wet‐dry tropics occur as habitat islands. Recent studies show that many patches are severely damaged by feral animals, weed invasion and contemporary fire regimes. This paper documents the status of an endangered palm species, Ptychosperma bleeseri, which occurs within a narrow geographical range in seven rainforest patches. Results of multivariate statistical analysis of quadrats with and without P. bleeseri show that the species does not appear to occupy all suitable habitat available at either a regional scale or within single rainforest patches. Evidence, based on demographic surveys, is presented for the current decline of P. bleeseri populations and possible causes for this decline are discussed; in particular, the impacts of wildfire and feral animal activity. Recommendations for a recovery plan for P. bleeseri are discussed, and include fencing, fire protection and public education.
The fate of nutrients during fires in a tropical savanna
Authors: COOK G. D.
Published: July 2006

Abstract
The nutrient loads contained in the grassy fuel before fires, and of ash subsequently, were compared to determine the fluxes of macronutrients, copper and zinc during fires at Kapalga in Kakadu National Park. The fluxes were estimated in three vegetation types: forest, woodland and open woodland. The magnitudes of the fluxes were greatest in the forest community where grassy fuel loads were highest at about 6.3 t ha−1. In these sites, 54–94% of all measured nutrients in the fuel were transferred to the atmosphere during the fires. For each nutrient, the proportion transferred to the atmosphere as entrained ash was calculated by assuming that calcium was not volatilized during the fires. If the transfer of entrained ash represents local redistribution only, then rainfall accession and the deposition of these particu‐lates should replace most of the losses of all nutrients except nitrogen (N). Estimated rates of biological fixation of N appear to be insufficient to replace the annual losses of N. It is therefore concluded that a regime of annual fires that completely burn the available grassy fuel would deplete N reserves in these savannas, unless there are other sources of biologically fixed N, which are unknown at present.
The cost of ad hoc reservation: A case study in western New South Wales
Authors: PRESSEY R. L. , TULLY S. L.
Published: July 2006

Abstract
We reviewed the literature on the practice of reservation in Australia over the past few decades. We found that reserves have generally been dedicated for expedient or opportunistic reasons and that they tend to protect the environments with least potential for commercial land uses. Ad hoc reservation has two main disadvantages: the environments most in need of strict reservation are not effectively protected; and natural diversity is represented inefficiently in terms of features per unit reserve area. We demonstrate the second disadvantage with quantitative comparisons of alternative reservation scenarios in the Western Division of New South Wales. These show that a continuation of ad hoc acquisition of reserves will continue to increase the land area needed to represent all natural environments and so reduce the likelihood of achieving a representative reserve system.
Foraging strategies ofEriophora transmarinaandNephila plumipes(Araneae: Araneoidea): Nocturnal and diurnal orb‐weaving spiders
Authors: HERBERSTEIN M. E. , Elgar M. A.
Published: July 2006

AbstractThe foraging behaviour, web characteristics and prey availability of two sympatric orb‐weaving spiders,Nephila plumipesandEriophora transmarina(Araneae: Araneoidea), are compared. The spiders are similarly sized but have different temporal foraging patterns.Nephila plumipesspins a relatively permanent web and captures most of its prey during the day.Eriophora transmarinaonly forages at night, spinning a new web every night and usually dismantling it at dawn. These different foraging activities are most likely to be responsible for the observed differences in the types and rates of prey capture:E. transmarinacaptured mostly Lepidoptera that were more abundant at night than during the day, whileN. plumipescaptured mostly Hymenoptera that were more abundant during the day than at night. While nocturnalE. transmarinahave less time available for foraging than the diurnalN. plumipes, the former has a substantially higher nocturnal prey capture rate. We argue that the difference between the species in their prey capture rates are likely to be due to differences in the architecture of their webs.
Emergence of Eucalyptus marginata (jarrah) from seed in Mediterranean‐climate forest in response to overstorey, site, seedbed and seed harvesting
Authors: STONEMAN G. L. , DELL B.
Published: July 2006

Abstract
The effects of overstorey, type of site, seedbed, seeding date and seed harvesting by vertebrates and invertebrates on the emergence of Eucalyptus marginata (jarrah) seedlings were studied experimentally in the northern jarrah forest of Western Australia. Seed harvesting by small vertebrates substantially reduced emergence, whereas invertebrates only slightly reduced emergence. Ninety per cent of seed was removed within 1 day when it was on the soil surface and in the open, whereas seed removal was insignificant when the seed was covered by soil. Vertebrates harvested seed more effectively when the understorey and litter were removed and the seed was more visible on the soil surface. Seed harvesting by small vertebrates had less impact on a site where there had been bauxite mining, possibly because the surrounding area was being revegetated with large numbers of seed and the area afforded poor cover for vertebrates. Emergence was less where the overstorey was removed compared to where it was retained, and on the rehabilitated bauxite mined site compared to the forest sites. There was no difference in emergence between the low and high quality forest sites and so the emergence phase could not fully explain the variation in abundance off. marginata seedlings on different quality sites. Post emergence events are likely to be important in explaining this difference between low and high quality sites.