bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cusps and pipis on a sandy ocean beach in New South Wales
Authors: James Rodney 
Published: March 2003

AbstractThe effect of small‐scale variation in beach morphology has been largely ignored in studies of beach macrofauna. This study examined the distribution and abundance of the large bivalve, Donax deltoides (commonly known as the ‘pipi’) in relation to beach cusps (rhythmically spaced undulations of the beachface consisting of scalloped bays and flanking horns on a scale of tens of metres). No differences were found in the abundance of pipis downshore of cusp horns versus cusp bays at any of three sites. In contrast, previous work on a relatively low‐energy (reflective) beach reported greater abundances of bivalves below cusp bays than below cusp horns. Results suggest that the swash climate on the higher‐energy (more dissipative) beach studied here produces weaker cusping and weaker patterns in the active or passive redistribution of beach fauna by swash action. Wider more dissipative beaches also allow beach macrofauna to remain on flatter parts of the beach, further below cusps than on reflective beaches. The more rigorous study design used here may also contribute to the difference in results between this study and previous studies. However, populations of pipis below cusp bays did contain a greater proportion of small individuals (≤20 mm length) than populations on cusp horns, suggesting some effect related to beach cusps. Small pipis live closer to the beach surface as they have shorter siphons and are subject to larger rates of dislodgement and movement from cusp horns to cusp bays by swash action than are large pipis. Future ecological studies of beaches with cusps should take beach cusps and the processes producing them into account as they may affect the distribution, abundance and the size distribution of beach invertebrates.
Technique for washing nectar from the flowers of Tasmanian leatherwood (Eucryphia lucida Eucryphiaceae)
Authors: Mallick Stephen A. 
Published: March 2003

AbstractThe technique for extracting floral nectar using micropipettes is often unsuited to flowers where nectar is produced in very small volumes and/or where nectar is highly viscous. An alternative technique for washing the viscous nectar from the flowers of Tasmanian leatherwood, Eucryphia lucida (Labill.) is described. Here, two washes with a known volume of distilled water removed 95% of total floral sugar. Using such a washing technique on exposed and bagged E. lucida flowers provided information on nectar production in this species that could not have been obtained using a standard micropipette extraction method.
What are the relative costs, limits and correlates of increased degree of serotiny?
Authors: Midgley Jeremy 
Published: March 2003

AbstractThere is variability in the period that serotinous species retain seeds in protective closed cones and in the sizes of the cones. Seed predation and inter‐fire recruitment have been suggested to be reasons for this variability. I argue against these two reasons. Variation in annual rates of increase in fecundity and in numbers of flowering episodes before fire should be correlated with the degree of serotiny. These two attributes are a consequence of cone size, plant architecture and degree of serotiny.
Landscape fragmentation in South Coast Renosterveld, South Africa, in relation to rainfall and topography
Authors: Kemper Jessica , Cowling Richard M. , Richardson David M. , Forsyth Greg G. , McKelly David H. 
Published: March 2003

AbstractThe South Coast Renosterveld has been fragmented extensively by agriculture. The extent of this fragmentation in terms of overall habitat loss, fragment sizes and fragment numbers has not been described previously, thereby limiting the development of conservation strategies for this vegetation type. Patterns of renosterveld loss in three sectors along a west–east gradient were described using LANDSAT imagery and a Geographical Information System‐based program (FRAGSTATS) for spatial pattern analysis. These patterns were then correlated with rainfall and topography measures, which are indicators of agricultural potential. Over 80% of the South Coast Renosterveld has been cultivated. Fragmentation levels increased significantly from east to west, with 33% of natural vegetation remaining in the east and only 4% in the west. Topographical variables were the strongest predictors of patterns of renosterveld loss, with fragments being largely confined to slopes too steep for ploughing; they therefore face little risk of future cultivation. These results have implications for conservation planning options for the South Coast Renosterveld. There is the potential for large reserves in the east, as well as corridor reserves along major river valleys, but for only small, isolated reserves in the west.
What’s in a site? Variation in lotic macroinvertebrate density and diversity in a spatially replicated experiment
Authors: Downes Barbara J. , Hindell Jeremy S. 
Published: March 2003

AbstractFew studies have tested whether a small‐scale, experimental difference in biotic density and diversity detected at one site has any predictive capacity at other locations, nor whether such experimental differences are significant relative to overall spatial variation. In this study, we tested textural differences between substrata– previously shown to be critical to macroinvertebrate density and diversity at one site on the Steavenson River in southeastern Australia–and replicated the experiment at this site and at two others on the same river, plus at three sites on each of two other rivers (the Acheron and Little Rivers) in the same catchment. Nine rough and nine smooth colonization substrata were set out at each site on 19 December 1995, and at the start of the experiment (26 and 27 February 1996), invertebrates were hand‐picked from substrata while leaving epilithon intact. We re‐collected substrata after 28 days. Substrate texture had a consistent and strong effect upon species richness at all sites, except one, and was also associated with compositional differences at the family level. Textural effects on macroinvertebrate densities were present and varied among sites and rivers somewhat, but only three of nine common species showed significant interactions between textural effects and one of the two spatial scales, and these interactions explained <10% of variance. In most but not all cases, textural effects were the same as that previously observed–higher numbers on rough surfaces compared to smooth. Most variation in species richness and densities was explained by site, which accounted for 30% of variation in species richness, 60% of total numbers of individuals, and 9–75% of variation in abundances in all nine common taxa. Site differences were also associated with large shifts in faunal composition at the family level. Differences between rivers explained 0% of the variance in most cases but it was significant in explaining the abundance of one common species (the beetle Simsonia wilsoni), where it accounted for 59% of the variance. Our results indicate that a small‐scale effect, such as textural differences between substrata, can produce a consistent effect on measures of community structure and have some predictive capacity at other locations. However, the large differences between sites, relative to those seen between whole rivers, suggest that efforts must be directed to discovering what factors cause such localized fluctuations. Sites cannot be reasonably used as ‘representative’ of larger spatial units, such as long sections of entire rivers. Additionally, rivers may not necessarily have signature variation that always overrides localized, site‐based differences.
Functional response and area‐restricted search in a predator: seasonal exploitation of anurans by the European polecat, Mustela putorius
Authors: Lode T. 
Published: March 2003

AbstractA study of the feeding habits and movements of 11 radiotracked polecats Mustela putorius in western France revealed that seasonal predation upon agile frogs, Rana dalmatina, was directly influenced by prey abundance and distribution. Although dietary structure showed the importance of mammalian prey (71.5%), polecats exploited nocturnal, terrestrial anurans in spring (31.6%). The periodic activity of anurans at spawning sites led both to a maximum density in spring and to a patchy distribution. The monthly variations in anuran dietary occurrences were associated with changes in frog availability. The functional response of polecats to frog density was sigmoidal shaped (type 3 response). Frog consumption rate increased more slowly than prey density but frogs were actively removed at higher density. It is therefore suggested that frog populations were moderately affected by the predator and this density dependent effect tends to stabilise anuran populations. Predation upon anurans was also correlated with a prey dispersion index as revealed by a polynomial regression. Polecats concentrated their predation on spawning congregations of the breeding adult frogs. Movements were smallest in spring and polecats changed their track length by increasing the difference between a succession of small movements and of longer journeys towards profitable sites. Changes in movements correlated with the anuran dispersion index and the response was sigmoidal (polynomial regression) revealing an area‐restricted search. This response may be regarded as an ‘aggregative response’ according to the first part of the definition of
Begon et al. (1996)
. Functional and area‐restricted search responses to the frog abundance and dispersion constitute an original example of predator‐prey coexistence strategies among vertebrates. I suggest that such predation could be favoured by the individualistic habits of the mustelid.
Genetic relationship of myrmecophyte (Anthorrhiza caerulea) individuals within and among territories of the arboreal ant (Dolichoderus sp.) detected using random amplified polymorphic DNA markers
Authors: Maeyama T. 
Published: March 2003

AbstractThe polymorphic bands of random amplified polymorphic DNA (RAPD) markers of the population of epiphytic myrmecophyte, Anthorrhiza caerulea Huxley & Jebb (Rubiaceae: Hydnophytinae), and those of its obligatory occupant ant, Dolichoderus sp. (Formicidae: Dolichoderinae), were analyzed in this study in a Papua New Guinean secondary forest. All the reproducible polymorphic bands were used as RAPD markers. Euclidean distances were calculated as the similarity indices of the band patterns, and similarities of the band patterns were analyzed using cluster analysis (group average method). It was frequently observed that the occupant ants gathered the seeds of A. caerulea and buried them into their carton trails on the bark of host trees. The colony boundaries of Dolichoderus sp. were assessed using RAPD analysis, and were clearly detected by this method. From the analyses of genetic relationships in the population of A. caerulea, it was revealed that the myrmecophytes within a certain ant territory consisted of close relatives. Therefore, it was inferred that the descendants of A. caerulea were dispersed only within the territory of a certain ant colony.
Foraging strategies of an insectivorous marsupial, Sminthopsis youngsoni (Marsupialia: Dasyuridae), in Australian sandridge desert
Authors: Haythornthwaite Adele S. , Dickman Christopher R. 
Published: March 2003

AbstractThis study investigated the effects of predation risk, dune position and microhabitat on foraging of the Lesser Hairy‐footed Dunnart Sminthopsis youngsoni, a small insectivorous marsupial, in the Simpson Desert of western Queensland. The intensity of foraging was assessed by establishing feeding stations (dishes containing mealworms) in open and bush microhabitats at three levels on sand dunes, and recording the numbers of prey taken by dunnarts from the stations after nightly bouts of foraging. Risk of predation was manipulated by provision of artificial illumination at alternate feeding stations on each of five occasions when trials were run. The numbers of mealworms left after feeding bouts varied inconsistently across trials, providing little evidence that dunnarts respond to habitat or predation risk while foraging. These results contrast sharply with studies of arid zone rodents, where foraging is usually sensitive to both predation risk and resource distribution. We suggest that S. youngsoni forages equally in all habitats of its sandridge environment, and experiences relatively low risk of predation whilst doing so.
Estimating forest habitat complexity in relation to time since fire
Authors: Coops Nicholas C. , Catling Peter C. 
Published: March 2003

AbstractForest structure does not form an even distribution over forested landscapes; rather, it produces a mosaic or patchwork pattern. ‘Habitat complexity scores’ provide a method of describing changes in vegetation biomass and, when assessed at randomly located plots, a frequency distribution of habitat can be developed. The frequency distribution can be used to describe characteristics of the pattern of habitat complexity, such as the mean and heterogeneity of habitat over the whole forest. In the present paper, an historical sequence of habitat complexity scores collected from 99 sites over an 18‐year period was used. The frequency distribution of the habitat complexity scores was fitted using a binomial distribution and the parameters of the binomial distribution were modelled to provide a relationship between the frequency of different habitat environments across the landscape and the time since wildfire. In most cases, the binomial distributions fitted the observed data significantly. The relationship between the binomial parameters and the time since fire was found to be highly significant (P < 0.01). Habitat complexity scores were predicted from the model solely as a function of time since fire, allowing both retrospective and future predictions of the distribution of habitats to be undertaken.
Genetic variation in the life‐history traits of Epiphyas postvittana: population structure and local adaptation
Authors: Gu Hainan , Danthanarayana Wijesiri 
Published: March 2003

AbstractThe light brown apple moth, Epiphyas postvittana (Walker) shows high intraspecific variability in morphological, physiological, demographic and behavioural characters. To gain insight into the extent of adaptation and evolutionary changes in response to environmental heterogeneity in this species, quantitative genetic analyses of life‐history variation were conducted for two natural populations under two thermal conditions (23°C and 28°C). Paternal half‐sib heritability and genetic correlation in six life‐history traits (i.e. development time, adult body weight, adult lifespan, age at first reproduction, the number of eggs laid during the first 5 days after emergence, and total fecundity) were compared. Significant heritabilities were shown consistently in development time; this is also true for adult body weight, except for the Canberra population at 23°C. However, neither population differences nor the effect of temperature were statistically detectable for any of these heritabilities, confirming the genetically determined flexibility. Positive genetic correlations between development time and adult body weight, and negative genetic correlations between the number of eggs laid during the first 5 days and adult lifespan were present for these populations at both temperatures, indicating the presence of genetic constraints. Pairwise comparisons of genetic correlations revealed the heterogeneity of the two populations and across temperatures. These results suggest that the structure of genetic covariance might have changed significantly during the divergence of natural populations and in response to the alteration of environmental conditions in E. postvittana.
Impact of an exotic vine Clematis vitalba (F. Ranunculaceae) and of control measures on plant biodiversity in indigenous forest, Taihape, New Zealand
Authors: Ogle C. C. , Cock G. D. La , Arnold G. , Mickleson N. 
Published: March 2003

AbstractThe exotic vine, Clematis vitalba L. (F. Ranunculaceae), has been in forest reserves around Taihape in the Rangitikei Ecological Region of the central North Island, New Zealand, for about 70 years. Before this weed was abundant, Taihape forests were rich in species of indigenous vascular plants, especially woody species. Clematis vitalba and its control are contributing to a loss of forest structure and of indigenous biodiversity at the ecosystem and species levels, to a lack of recruitment of indigenous species, to an influx of other weeds and to changes in growth forms of indigenous shrubs. Species that have disappeared or become uncommon in forest with C. vitalba tend to be those that are nationally threatened or uncommon, have restricted distributions or are biogeographically significant. Current control of C. vitalba in the Taihape forest is piecemeal and long‐term. It is based on mechanical and chemical methods, followed by grazing with sheep to prevent regeneration. Recommendations are made for rapid removal of C. vitalba from all untreated parts of the reserve, followed by manual control or spot‐ spraying, permanent removal of sheep, control of other serious weeds and implementation of a restoration programme.
Small mammals as potential seed dispersers in New Zealand
Authors: Williams Peter A. , Karl Brian J. , Bannister Peter , Lee William G. 
Published: March 2003

AbstractWeed invasion success is strongly influenced by availability of seed dispersal vectors, which may include animals. We examined the potential of several small introduced mammals (mice, kiore, ship rats and possums) to disperse germinable seeds in New Zealand. Captive animals were fed fleshy fruit of weeds (Berberis glaucocarpa, Cotoneaster spp., Crataegus monogyna, Ilex aquifolium, Leycesteria formosa, Ligustrum sinense, Lonicera japonica, Passiflora mollissima, Pyracantha angustifolia, Sorbus hupehensis) and native species (Coprosma spp., Prumnopitys ferruginea and Solanum aviculare). We recorded the percentage of fruit consumed, seed ingested and gut passage time. Faeces were collected and the seeds extracted and tested for germination potential in an unheated glasshouse (two weed species) or under controlled conditions (11 species). The smallest rodents (mice and kiore) generally destroyed all seeds eaten. Large numbers of viable seeds of the small‐seeded (<1 mg) species, L. formosa and S. aviculare, passed through ship rats. Possums consumed the seeds of all adventive and native fruits except P. ferruginea. The proportion of seeds recovered intact from possum faeces varied with plant species and ranged from 6 to 83%. The time required for 50% of all seeds to be passed by possums ranged from 2.5 to 5.5 days with an average of 3.7 days, and was generally unrelated to simple fruit parameters such as percentage pulp and moisture content. For seeds where germination also occurred in the uneaten controls, the germination of seed from possums ranged from 3 to 78%. Germination was mostly lower in seeds from possums than in the controls, where differences were significant. Possums have major potential to disperse a wide range of fleshy fruit‐producing native and introduced plant species. Ship rats have the potential to disperse those with very small seeds.
Urbanization and exotic plants in northern Sydney streams
Authors: King Scott A. , Buckney Rod T 
Published: March 2003

AbstractThe vegetation and sediment of urban and non‐urban streams in the northern Sydney region were compared to examine the possible effects of urbanization on within‐stream vegetation. Many sediment characteristics were significantly different in urban streams. At least one exotic plant species was found in each urban stream sampled, but none were found in the non‐urban streams. The presence of exotic species led to the overall number and abundance of plant species being significantly higher in urban streams. Interestingly, the number and abundance of native species at the urban sites were the same as non‐urban sites, but a different suite of species was usually present. This suggests that urban streams favour exotic plants and certain native plants that are adapted to the modified conditions. The differences between the plant communities in the urban and non‐urban streams appeared to be associated with the increased level of nutrients in the urban stream sediment. Several multivariate techniques were used to assess the relative importance of individual nutrients, but no nutrients were directly associated with the observed differences. In particular, total phosphorus levels were less important in explaining the vegetation patterns than a combination of nutrients. It is therefore likely that the general increase of nutrients in stream sediment has enhanced exotic invasion and altered stream plant communities in Sydney streams.
Soil‐mediated effects on germination and seedling growth of coastal wattle (Acacia sophorae) by the environmental weed, bitou bush (Chrysanthemoides monilifera ssp. rotundata)
Authors: Vranjic John A. , Woods Matthew J. , Barnard Julian 
Published: March 2003

AbstractBitou bush (Chrysanthemoides monilifera ssp. rotundata; Asteraceae) is a major woody weed that competes with the native legume Acacia sophorae in coastal ecosystems of eastern Australia. Three glasshouse experiments examined whether litter or soil from beneath bitou bush or Acacia plants could influence seed germination and seedling growth of A. sophorae. The presence of litter decreased seed germinability and this effect was greater for bitou bush litter than for Acacia litter. Shoot growth was increased by the addition of Rhizobium after 40 days, irrespective of soil type. After 78 days, shoot and root biomass were significantly lower for seedlings grown in bitou bush soil than for those grown in Acacia soil. There was a non‐significant trend towards a lower median population of Rhizobium in the soil beneath bitou bush than in that beneath Acacia. The results demonstrated a slight effect of bitou bush on the growth of A. sophorae, which could, however, be overshadowed by the judicious use of herbicides or fire for weed control and revegetation.
Decomposition of Avicennia marina on an iron‐smelting slag substrate
Authors: Dick T. M. , Streever W. J. 
Published: March 2003

AbstractThe present study, conducted near Newcastle, Australia, used a blocked analysis of variance experimental design to compare initial nutrient concentrations and decomposition rates of Avicennia marina (grey mangrove) grown on sand and rock blast furnace slag. There were no significant differences (

ANOVA; P > 0.05) in mean initial nutrient concentrations of total C, N and P for plants grown on the sand and slag substrates. A litterbag technique was used to estimate decomposition rates. After 360 days of incubation, repeated measures analysis did not identify significant differences between the substrates for the interaction term ‘substrate × time’ or the term ‘substrate’ for percentage weight loss or for C, N and P remaining. Avicennia marina on both substrates had nutrient characteristics and decomposition rates comparable to those found in the literature. Results suggest that initial nutrient concentration and decomposition rates are not dramatically influenced by the presence of slag.