bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response of ant and terrestrial spider assemblages to pastoral and military land use, and to landscape position, in a tropical savanna woodland in northern Australia
Authors: Woinarski John C. Z. , Andersen Alan N. , Churchill Tracey B. , Ash Andrew J. 
Published: March 2003

Abstract This study aims primarily to assess the response of two invertebrate groups to the effects of pastoralism and military training, at one site in the tropical savanna of north‐eastern Queensland. The richness and species composition of ants and terrestrial spiders were examined at two contrasting times of year across three land use treatments (pastoralism, military training and undisturbed) and four landscape positions (upper slope to riparian). Ant species richness was least in the grazed sites, and a high proportion of the ant species recorded varied significantly in frequency between the grazed and the two ungrazed land uses. This variation was generally greater than that associated with landscape position. Although variation in the richness of spiders was significantly related to land‐use type, this effect was less pronounced than for ants, was less marked than variation associated with landscape position and was confounded by a strong interaction between land use and landscape position. Quadrat‐scale variation in the composition of spider assemblages was influenced most by season of sampling. For both spiders and ants, there were few differences in richness or species composition between undisturbed land and that managed for military use.
Interspecific competitive ability of homokaryotic and heterokaryotic wood decay basidiomycetes
Authors: Fryar S. C. , Kirby G. C. , Hyde K. D. 
Published: March 2003

Abstract The role of the homokaryotic life stage in the dynamics of fungal communities is relatively unknown. However, homokaryons are thought to be only a temporary stage and are therefore not generally used in ecological experiments with fungi. In this study, the relative competitive ability and growth rates of homokaryons and heterokaryons of wood decay fungi were tested to assess the potential role of homokaryons in community dynamics. A homokaryon and a heterokaryon of each of four species (Aleurodiscus lividocoeruleus, Peniophora sp. 1, Peniophora sp. 2 and Pereniporia medulla‐panis) were assessed for their competitive abilities on an agar medium. The relationship between nuclear status and competitive ability varied between species. The homokaryon of Peniophora sp. 2 was competitively superior to its heterokaryon, whereas the homokaryon of Peniophora sp. 1 was inferior to its heterokaryon. A hierarchy of competitive abilities of each isolate revealed that Pereniporia medulla‐panis homokaryon = P. medulla‐panis heterokaryon > Peniophora sp. 1 heterokaryon > Peniophora sp. 2 homokaryon > Peniophora sp. 2 heterokaryon > A. lividocoeruleus heterokaryon = A. lividocoeruleus homokaryon. This experiment indicates that homokaryons as well as heterokaryons have the potential to influence community structure through competitive effects.
Selective predation on the broad‐toothed rat, Mastacomys fuscus (Rodentia: Muridae), by the introduced red fox, Vulpes vulpes (Carnivora: Canidae), in the Snowy Mountains, Australia
Authors: Green K. 
Published: March 2003

Abstract  Since 1981 there has been debate over whether foxes (Vulpes vulpes Linnaeus) selectively prey on the broad‐toothed rat (Mastacomys fuscus Thomas) relative to the bush rat (Rattus fuscipes (Waterhouse)). In the present study, three areas of the argument are examined. (i) In a study of fox diet over 3 years at both alpine and subalpine altitudes, M. fuscus outnumbered R. fuscipes in faecal remains in all seasons, in all years, and at both altitudes. Overall, M. fuscus occurred in scats five times as frequently as did R. fuscipes in the alpine zone and twice as often in the subalpine zone. (ii) Data from population studies of M. fuscus and R. fuscipes showed no evidence that M. fuscus is trap shy; neither the pattern of captures of individuals caught once, twice and so on, nor the proportion of the estimated population of each species captured during trapping sessions was significantly different. (iii) The suitable habitat for M. fuscus within the potential home ranges of foxes contributing to the subalpine fox scat collection constituted approximately 50% of the total area. However, there was no significant difference between the numbers of fox trails encountered in habitat suitable or unsuitable for M. fuscus in 19 paired transects skied in winter, indicating no preferential foraging in either habitat. Selective feeding on M. fuscus was therefore established, but how that choice is exercised was not determined.
Patch dieback of Colophospermum mopane in a dysfunctional semi‐arid African savanna
Authors: Macgregor Shaun D. , O'Connor Timothy G. 
Published: March 2003

Abstract  Patch dieback occurred in an almost monospecific Colophospermum mopane (Kirk ex Benth.) Kirk ex J. Léonard woodland in the Northern Province, South Africa, following severe droughts in 1988–1989 and 1991–1992. Discrete patches of dieback and adjacent paired areas of ‘healthy’ vegetation lost an average of 87 and 13% of basal area to mortality, respectively. Whole trees mostly died on ‘dead’ plots, while single‐stem mortality prevailed on ‘live’ plots. Tree mortality decreased with increasing stem number per tree. Patch dieback did not occur on sandy soils. On fine‐textured soils, variation in soil type, topography or slope did not affect dieback. Dieback was influenced by vegetation structure, soil surface condition and soil chemistry. Intense intertree competition, shown by self‐thinning occurring prior to dieback, was a precondition for dieback. Intertree competition had heightened during the 30 years prior to dieback because of an increase in woody cover. Dieback patches had changed from functioning as sinks of water and sediment to sources of these as a result of loss of perennial herbaceous cover, decreased water retention on bared surfaces, and accelerated erosion during 50 years of livestock ranching. Vegetation had thus become increasingly drought‐prone, exacerbated in places by soils with a high sodium concentration. Dieback had occurred because the water requirements of C. mopane could no longer be met during drought years on the dysfunctional patches.
Influence of woodland remnant edges on small skinks (Richmond, New South Wales)
Authors: Anderson Lyn , Burgin Shelley 
Published: March 2003

Abstract  Habitat fragmentation due to clearing often results in an increase in edge areas compared with overall remnant size, but there are limited data on the influence of increased edge areas on generalist species. Therefore, the abundance of small (<55 mm) generalist scinid lizards in small woodland remnants of the Cumberland Plain (western Sydney, Australia) was compared. Using pitfall trapping and points of transect survey techniques, three species were encountered: Lampropholis guichenoti, Lampropholis delicata and Cryptoblepharus virgatus. The abundance and diversity of these skinks differed significantly between edge and core areas; fewer individuals were encountered on the edge of the remnants than in core sites. Cryptoblepharus virgatus was only observed in edge sites where L. guichenoti made up the greatest skink abundance. In contrast, L. delicata abundance was greatest at core sites. There was also a significant difference between the edge and core with respect to the size structure of the L. guichenoti population. Larger numbers of subadults were observed in the edge sites, whereas there were significantly fewer adults and juveniles in these areas. Habitat characteristics did not account for the skink distribution observed.
Are there commonalities among audit tools used to measure carotid endarterectomy outcomes in New South Wales?
Authors: Middleton Sandy , Ward Jeanette ,   on behalf of the New South Wales Carotid Endarterectomy Audit Project Working Group
Published: March 2003

Background: To prepare for a state‐wide audit of carotid endarterectomy (CEA), we sought to ascertain pre‐existing practices and identify common process and outcome measures among audits tools used by NSW vascular surgeons. Method: Telephone survey comprising five questions about CEA audit practices. Results: Of 37 known vascular surgeons in NSW, all performed CEA and agreed to participate in our telephone survey (response rate 100%). All but one reported collecting CEA data (97%). Two thirds of these collected data prospectively. From those 19 surgeons (51%) who stated that they used standard tools for audit, we received five CEA‐specific tools. Process measures common to all five were: side of CEA, date of operation, sex, past history of hypertension, history of diabetes, use of shunt, use of patch. There were only three outcome measures common to all five CEA‐specific tools: postoperative transient ischaemic attack (TIA), postoperative stroke, and postoperative death. Data about outcomes beyond discharge were inconsistently collected. Conclusions: While most vascular surgeons in NSW report collecting information about CEA outcomes, not all do so prospectively. Only three outcomes (postoperative TIA, postoperative stroke and death) were common to all tools, inviting the development and use of a comprehensive and standard tool.
Walnut development affects chemical composition and codling moth performance
Authors: Bezemer T. Martijn , Mills Nick J. 
Published: March 2003

Abstract1 We investigated for early and late blooming walnut cultivars in California whether variation in nut phenology resulted in differences in nutritional quality and whether this, in turn, affected the performance of the codling moth, Cydia pomonella (L.), and the extent of nut damage.2 Mid‐season, during the period of nut growth, nuts from the early cultivars were larger than those from the late cultivars and had higher nitrogen content in both husk and kernel tissue, while kernel phenolic content was significantly lower. No major differences were observed later in the season after nuts from all cultivars had reached their final size.3 Throughout the season establishment of neonate larvae was highest on nuts from the early cultivars but this was only significantly so at the beginning of the third codling moth generation. During the second codling moth generation (mid season) relative growth rates of third‐instar larvae were significantly higher on early than on late cultivars. Nut damage in the field was also significantly greater on early than on late cultivars during generation 2, while no significant differences were observed during generation 3.4 The data suggest that the variation in codling moth damage among walnut cultivars is related to bloom phenology due to the influence of nut phenology on larval performance.
Spiders (Araneae) associated with downed woody material in a deciduous forest in central Alberta, Canada
Authors: Buddle Christopher M. 
Published: March 2003

Abstract1 Spiders (Araneae) were collected on and near downed woody material (DWM) in aPopulus‐dominated forest to determine if spiders utilize wood surfaces, and to ascertain the importance of DWM habitat and wood elevation for spider assemblages.2 Over 10 000 spiders representing 100 species were collected. Although more spiders were collected on the forest floor, spider diversity was higher in traps located on wood surfaces than on the forest floor, and 11 species were collected more frequently on wood surfaces.3 Spiders utilized DWM at different stages in their development. FemalePardosa mackenziana(Keyserling) (Lycosidae) carrying egg sacs were caught most often on the surface of DWM, possibly to sun their egg sacs. Additionally, the proportion of immature spiders was higher on the wood surface than on the forest floor.4 Spiders collected on logs with and without bark were compared to assemblages collected on telephone poles to assess what features of DWM habitat may be important. Web‐building species were seldom collected on telephone poles, suggesting that they depend on the greater habitat complexity provided by DWM. In contrast, hunting spiders did not distinguish between telephone poles and logs.5 Fewer spiders and a less diverse fauna utilized elevated compared to ground‐level wood. Additionally, Detrended Correspondence Analysis revealed that the spider community from elevated wood was distinguishable from the spider community from ground‐level wood, and from the forest floor spider community.
The history and control of the pine beauty moth, Panolis flammea (D. & S.) (Lepidoptera: Noctuidae), in Scotland from 1976 to 2000
Authors: Hicks B. J. , Barbour D. A. , Evans H. F. , Heritage S. , Leather S. R. , Milne R. , Watt A. D. 
Published: March 2003

Abstract1 The pine beauty moth, Panolis flammea, has been a serious pest of lodgepole pine plantations in Scotland since 1976. It historically feeds on native Scots pine throughout Europe but population levels of P. flammea on this host have never been high enough to cause tree mortality in the U.K.2 This paper reviews recent advances in the biology of the pest and documents control programmes from 1976 to 1999.3 There has been practically uninterrupted population monitoring of P. flammea from 1977 to the present day in Scottish lodgepole pine plantations. Intervention with chemical spraying has often been necessary.4 The population data suggest that populations of P. flammea may have had a cyclic pattern over the monitoring period, with outbreaks occurring at regular intervals of between 6 and 7 years.5 The amplitude of population cycles was large during the 1970s and 1980s, but has dampened in recent years. Natural enemies are believed to contribute to this trend. Fungal disease, specifically, appears to have had a greater effect on pest populations in recent years than in the past and is suggested to have contributed significantly to the population dynamics observed since 1990.
Interaction between relative humidity and resistance to Dasineura tetensi in blackcurrant
Authors: Hellqvist Sven 
Published: March 2003

Abstract1 Infestation by the blackcurrant leaf midge Dasineura tetensi and galling incidence on a susceptible (cv. ‘Öjebyn’) and a moderately resistant (cv. ‘Storklas’) blackcurrant genotype was studied in the field for two midge generations in the same growing season. On the resistant genotype gall initiation is delayed.2 The relation between infestation and galling incidence showed considerable variation between the two generations. Galling symptoms produced by the second midge generation were weak on the resistant as compared with the susceptible blackcurrant.3 Because larval development of that generation coincided with a period of dry and warm weather, it is possible that larvae on the resistant genotype suffered desiccation to a greater extent than larvae on the susceptible genotype where gall development was stronger.4 The possible interaction of relative humidity and expression of resistance was investigated in controlled environment experiments. The resistant ‘Storklas’ and a susceptible (‘7801–31’) currant genotype were studied at two constant relative humidities, 30 and 70%.5 Larvae of D. tetensi suffered from higher mortality and reduced growth rate on both genotypes in the low humidity environment.6 There was also a significant plant genotype by humidity interaction on larval performance; no galls were produced and no larvae completed development on the resistant currant at low humidity.7 There was a trend for a positive correlation between larval length and larval density on a plant at low humidity but not at high humidity.
Interactions between green spruce aphid (Elatobium abietinum (Walker)) and Norway and Sitka spruce under high and low nutrient conditions
Authors: Straw N. A. , Green G. 
Published: March 2003

Abstract1 Green spruce aphid (Elatobium abietinum) is a serious pest of spruce (Picea spp.) in north‐west Europe, causing defoliation of one‐year‐old and older needles.2 Relationships between population development of E. abietinum, needle loss and tree growth were compared for five pure genotypes of Sitka spruce and mixed‐genotype material of Sitka and Norway spruce, grown under high and low nutrient conditions.3 Despite wide differences in flushing date between spruce genotypes, E. abietinum populations peaked on the same date on each genotype and on the mixed‐genotype material, irrespective of nutrient supply.4 Larger aphid populations developed on trees grown under high nutrient conditions than under low nutrients. However, more needles were lost per aphid in the low nutrient treatment and overall defoliation rates in the two nutrient treatments were similar.5 Total aphid numbers differed significantly between Sitka spruce genotypes within nutrient treatments, but not in relation to bud‐burst or needle terpene content. Reductions in height growth caused by infestation were greater (15–44%), and related to mean aphid densities and defoliation, in the low nutrient treatment, but were smaller (11–27%) and not related to aphid density and defoliation in the high nutrient treatment.6 Development of E. abietinum populations was similar on Norway and Sitka spruce, but Norway spruce lost fewer needles. However, the effects of infestation on tree growth were more closely related to aphid density and were similar for Norway and Sitka spruce.7 Infestation caused a decrease in total root dry weight of Norway and Sitka spruce in proportion to the reductions observed in above‐ground growth.
Diet‐dependent fecundity of the spidersAtypena formosanaandPardosa pseudoannulata, predators in irrigated rice
Authors: Sigsgaard Lene , Toft Søren , Villareal Sylvia 
Published: March 2003

Abstract1 The fecundity of the spidersAtypena formosanaandPardosa pseudoannulatawas assessed on diets of brown planthopperNilaparvata lugens(BPH), green leafhopperNephotettix virescens(GLH), Collembola (Entomobryidae),Droso phila melanogasterand three prey mixtures; BPH–GLH, BPH–GLH–Collembola and a full mixed diet of BPH–GLH–Collembola–D. melanogaster.2 Egg production and hatching success was high inA. formosanaexcept on the BPH, the GLH and the BPH–GLH diets. InP. pseudoannulataegg production and hatching success was lowest on diets of GLH and BPH–GLH, whereas this spider used BPH better.3 Differences between offspring sizes were small.4 Survival ofA. formosanafemales was lowest on the GLH and BPH–GLH diets. InP. pseudoannulatasurvival did not differ significantly.5 Food conversion efficiency was highest on the Collembola and theD. melanogasterdiets for both spiders.6 Overall, diets of Collembola andD. melanogasterhad the highest quality for both spiders, the BPH–GLH–Collembola and the full mixed diets were intermediate in quality, the quality of the BPH diet was intermediate to low and quality of the GLH and BPH–GLH diets was low.7 There need not be a contradiction between low dietary value of hoppers and successful natural biological control provided that the nutritional needs of the spiders are met by sufficient alternative prey.8 The hopper‐spider relationship is comparable to that of aphids and spiders in temperate cereals, suggesting that low dietary quality of Homopterans to spiders may be widespread.
Interactions between the willow beetle Phratora vulgatissima and different genotypes of Salix viminalis
Authors: Peacock L. , Herrick S. , Harris J. 
Published: March 2003

Abstract 1 Planting of species mixtures is a strategy for the non‐chemical management of willow beetles in short‐rotation coppice willows. However, the relatively susceptible Salix viminalis genotypes and their hybrids dominate current high‐yielding willows. Interactions between Phratora vulgatissima and different genotypes of S. viminalis were examined under laboratory conditions to determine if these genotypes exhibit genetic differences in susceptibility to willow beetle damage.2 Seven S. viminalis genotypes and four hybrids were tested for the feeding preference of adult P. vulgatissima, larval performance and within‐season plant response to manual defoliation (50% and 75%).3 The feeding preference of adult beetles, the growth rate of larvae, and the weight at 33 days of larvae and pupae differed significantly between genotypes. Genotypes also differed significantly in their height and weight responses to mechanical defoliation. Two genotypes were taller, with longer internodes, after defoliation than were undamaged plants. Two hybrids and their S. viminalis parent showed no significant reduction in final dry weight between 0% and 50% defoliation treatments.4 Susceptibility of genotypes to adult feeding was not correlated with their tolerance to defoliation in terms of weight or height responses; however, larval growth rate on genotypes was negatively correlated both with final height and number of leaves after 75% defoliation and with the susceptibility of genotype to adult feeding.5 Salix viminalis showed genetic differences for all parameters tested. This suggests that the planting of a mixture of these genotypes would contain genetic differences with respect to host susceptibility to P. vulgatissima. Some parameters showed similarities between a hybrid and its parent, whereas others showed differences between siblings. This offers potential for effective breeding of desirable traits.
The impact of spruce aphids on nutrient flows in the canopy of Norway spruce
Authors: Stadler Bernhard , Michalzik Beate 
Published: March 2003

Summary1 This study investigated the effects of honeydew from aphids in the canopy of Norway spruce (Picea abies (L.) Karst.) on the nitrogen chemistry of throughfall using a rainfall simulation experiment. Throughfall collected beneath infested trees was compared with that from beneath uninfested trees, while standardizing the quality and quantity of the precipitation and plant age.2 Honeydew excreted by Cinara pilicornis (Hartig) and C. costata (Zett.) significantly increased the concentrations of dissolved organic carbon (DOC) and hexose‐C in throughfall. The average concentrations of nitrogenous compounds (NH4‐N, NO3‐N) in throughfall collected beneath infested trees were significantly lower than beneath uninfested trees.3 Multiple regression analysis indicated that the amount of rain and NH4‐N concentrations were the best predictors of the concentrations of dissolved organic nitrogen (DON) in throughfall. Parameters that were closely associated with the level of infestation (DOC, hexose‐C concentrations) did not have a direct relationship with DON. About 40% of the reduction in the concentration of DON in the throughfall was attributed to aphid–micro‐organism interactions.4 Particle amino nitrogen (PAN)‐concentrations were highest under infested trees in July after aphid numbers had declined, indicating a concomitant decline in microbial biomass after honeydew becomes a limiting resource.5 The comparison of the concentrations of different nitrogen compounds in throughfall of infested and uninfested trees indicated that aphids affect the carbon and nitrogen cycles in the phyllosphere by providing energy that fuels the metabolism of the micro‐organisms. These processes seem to occur very rapidly.6 We discuss the significance of the results and the prospects of linking the ecology of micro‐organisms and herbivores with flows of nutrients through the canopy of trees.