bluuebunny/crossref_metadata_2025_split huggingface dataset:
Further studies on acclimatization to low temperatures in the grain weevils Sitophilus oryzae (L.) and Sitophilus granarius (L.)
Authors: EVANS D. E. 
Published: July 2006

AbstractThe effect of thermal acclimatization on the resting metabolism of adult grain weevils was examined by closely restraining the weevils during respirometry. Sitophilus oryzae (L.) acclimatized to 15°C consumed less oxygen over 11–23°C than 27°C‐acclimatized weevils but like amounts over 25–35°C. Similar results were observed with S. granarius (L.).Respiration R–T curves of unrestrained S. oryzae and S. granarius showed no evidence of rotation at temperatures close to their chill‐coma thresholds but warm‐ and cold‐acclimatized weevils consumed similar amounts of oxygen when both categories of weevils were in chillcoma.Acclimatizing S. oryzae from 27 to 13.5°C through four, weekly 4.5°C step‐transfers lowered the median chill‐coma thresholds of the weevils from 8.9 to 6.2°C, increased their life span at 9°C, an unfavourable temperature for this species, from 2 to 8 weeks and lowered their oxygen uptake at 9°C by 19%.
The effect of temperature on the population growth potential of Culex annulirostris Skuse (Diptera: Culicidae)
Authors: McDONALD G. , McLAREN I. W. , SHELDEN G. P. , SMITH I. R. 
Published: July 2006

AbstractThe effect of temperature on the population growth potential of Culex annulirostris was determined by studying larval growth rate and survival at seven temperatures between 10 and 40°C, and adult survival and fecundity at 20, 25 and 30°C. All larvae died at Wand 40°C; survival was greatest at 25°C. The period for complete juvenile development ranged from 8.57 days (35°C) to 37 days (15°C). Development from egg to adult required 196 day‐degrees above 9.7°C with incubation temperatures between 15 and 30°C. Population growth potential was positive at 20, 25 and 30°C, greatest at 25°C, but negative at 15°C. The minimum temperature for population growth was estimated as 17.5°C.
The effect of clipping on self‐thinning in Trifolium pratense
Authors: WESTOBY MARK , BROWN LEE 
Published: July 2006

AbstractThe self‐thinning rule describes mortality in a crowded even‐aged stand as a function only of biomass accumulation. We tested this prediction by stopping biomass accumulation with clipping treatments in Trifolium pratense. Moderate levels of clipping slowed thinning mortality considerably, but did not stop it entirely.
Estimating bark thickness in natural stands of Eucalyptus
Authors: GRASSIA A. 
Published: July 2006

AbstractInformation on bark thickness at various heights is sought to predict damage to trees by forest fires. A procedure which for natural stands of some smooth bark eucalyptus species enables the estimation of bark thickness at different heights from a single girth measurement at one metre height is discussed. The method utilizes the relationships of average girth, average bark thickness, and the regression coefficients of girth and bark thickness at given height positions, with height at one metre. The height positions are determined on a calibrating sample of about thirty trees of different sizes. Furthermore it is shown how the above information can be used to estimate bark volume, and hence bole volume, for Eucalyptus species of some commercial importance such as E. viminalis. Four species are considered: E. viminalis, E. pauciflora, E. mannifera and E. radiata.
Seasonal variation in insect abundance among three Australian rain forests, with particular reference to phytophagous types
Authors: LOWMAN MARGARET D. 
Published: July 2006

AbstractMonthly sweep net and light trap samples were used to examine seasonal changes in the abundance of insects in subtropical, warm and cool temperate rain forest in New South Wales. Maximum insect abundance, especially of phytophages, coincided with leaf flushing in the canopy trees. Cool temperate insect numbers were highest during the month just following the beech leaf flush, a rapid and synchronous growth event. Conversely, numbers of subtropical insects fluctuated over a longer period, in a pattern similar to the continuous growth of leaves that occurred throughout spring and summer there. The warm temperate was intermediate in its vegetation growth phenology and insect patterns. Rainforest insect abundance varied both temporally and spatially.
Influence of floristic composition on the net primary production and dry matter turnover in a tropical grassland
Authors: GUPTA S. R. , SINGH J. S. 
Published: July 2006

AbstractPlant biomass, net primary productivity and dry matter turnover were studied in a grassland situated in a tropical monsoonal climate at Kurukshetra, India (29°58′N, 76°51′E). Based on differences in vegetation in response to microrelief, three stands were distinguished on the study site. The stand I was dominated by Sesbania bispinosa, stand II represented mixed grasses and stand III was dominated by Desmostachya bipinnata. Floristic composition of the three stands revealed the greatest number of species on stand II (75). The study of life form classes indicated a thero‐cryptophytic flora. The biomass of live shoots in all the three stands attained a maximum value in September (424–1921 g m‐2) and below ground plant biomass in November (749–1868 g m‐2). The annual above ground net primary production was greatest on stand I (2143 g m‐2) and lowest on stand II (617 g m‐2). The rate of production was highest during the rainy season (15.34 to 3.18 g m‐2 day‐2). Below ground net production ranged from 1592 to 785 g m‐2 y‐2 and the rates were high in winter and summer seasons. Total annual net primary production was estimated to be 3141, 1403, 2493 and 2134 g m‐2 on stands I, II, III and on the grassland as a whole, respectively. The turnover of total plant biomass plus below ground biomass indicated almost a complete replacement of phytomass within the year. The system transfer functions showed greater transfer of material from total net primary production to the shoot compartment during rainy season and to the root compartment during winter and summer seasons.
Modelling population growth in stage‐grouped organisms: a simple extension to the Leslie model
Authors: WOODWARD I. O. 
Published: July 2006

AbstractA simple method for decomposing a population's stage grouping into the underlying age structure is described. The population's dynamics can then be predicted using standard age‐structured models, such as Leslie's matrix model. The method overcomes objections to previous attempts to use Leslie's procedure for modelling population growth in stage‐grouped organisms. A hypothetical example is used to illustrate the new technique.
Seed characteristics and regeneration of some species in invaded coastal communities
Authors: WEISS P. W. 
Published: July 2006

Abstract The seed production, germination and regeneration characteristics of two native species (Acacia longifolia var. sophorae and Banksia integrifolia) and two invasive subspecies (Chrysanthemoides monilifera ssp. monilifera and ssp. rotundata) were compared.C. monilifera ssp. rotundata was similar in seed characteristics and regeneration to B. integrifolia in that: (1) seed production was over an extended period each year; (2) seed longevity was low (0–2% viable after burial for 3 years), but increased with depth of burial; and (3) regeneration from 26 to 28% of mature plants occurred after fire. By contrast, C. monilifera ssp. monilifera was similar to A. Iongifolia var. sophorae in that; (1) seed production was over a short period each year; (2) of the total buried, 6–13% of seeds were viable after 3 years, and again numbers increased with depth of burial (percentages of missing seeds of A. longifolia were high but all remaining seeds were viable after 3 years); and (3) regeneration after fire occurred only from seed, hence their seed longevity is an important factor for long‐term survival. However, growth habit and niche occupation by ssp. rotundata is similar to that of A. longifolia and the above differences may contribute to the observed displacement of the native by the invasive species. The distribution of the two invasive subspecies is at present largely in separate areas in Australia and it is predicted this situation will continue because of their differing climatic preferences, morphology and regeneration from fire.
Biological survey and reserve design by Landsat mapped ecoclines — a catastrophe theory approach
Authors: SAXON E. C. , DUDZINSKI M. L. 
Published: July 2006

AbstractThe hypothetical correlation between temporal and spatial patterning in Landsat data and temporal and spatial heterogeneity required by persistent small populations of animals vulnerable to extinction has been tested by a biological survey and then applied to the design of a biological reserve. Vulnerable animals were associated with gradual gradients (ecoclines) in multi‐temporal texture transforms of Landsat imagery. Potential pest species and sites without fauna were associated with textureless areas and with abrupt boundaries. An area 150 000 km2 of the Tanami Desert in central Australia was mapped. The data were utilized to order biological reserve priorities.
Vegetation and flora associated with localized snow accumulation at Mount Field West, Tasmania
Authors: GIBSON NEIL , KIRKPATRICK J. B. 
Published: July 2006

AbstractThe vegetation associated with a snow patch at Mt Field in Tasmania is described and mapped. Seven distinct vegetation types were found to be related directly to topography and hence to the patterns of snow accumulation, snow melt and soil drainage. The fjaeldmark found where snow lies longest is unusual for Tasmania and may be the product of past climatic events and a peculiar parent material. At the generic level there exists a high similarity with the snow patch flora of the Australian Alps.
The demography of the temperate mangrove [Avicennia marina (Forsk.) Vierh.] at its southern limit in New Zealand
Authors: BURNS B. R. , OGDEN J. 
Published: July 2006

AbstractAn expanding monoculture of the mangroveAvicennia marinavar. resinifera growing at its southern limit in New Zealand was modelled using a Leslie matrix technique which assumed exponential population growth.The predictions from the model were partially verified from sequential aerial photographs of the population. The results add to a growing body of practical experience in the application of matrix techniques to plant demography.Modelling indicates that survivorship of the young tree size class is the main determinant of the population growth rate; annual seed production is relatively unimportant.Avicenniatrees produce relatively few large viviparous propagules, each of which has a high probability of establishment. Seedlings are retained in a ‘seedling bank’ for several years.The λ value of 1.2228 reflects the colonizing ability of the species, and is compared with published values for other species.
Habitat preferences of small mammals in tropical open‐forest of the Northern Territory
Authors: FRIEND GORDON R. , TAYLOR JOHN A. 
Published: July 2006

AbstractPattern analysis was used to investigate the habitat preferences of five small mammal species in tropical open‐forest of the Northern Territory. Fifty‐one sites were classified by faunal abundance and the groups examined for significant differences in vegetation structural attributes and plant species in both dry and wet seasons.The omnivore Isoodon macrourus showed strong association with floristic and vegetation structural attributes only in the dry season, when areas with a dense understorey of small trees and shrubs and a high percentage of leaf litter cover were favoured. Of the two primarily carnivorous species, Antechinus bellus was related strongly with floristic and structural attributes in both seasons and showed a consistent preference for areas with relatively dense low‐level foliage (< 2m). By contrast, Dasyurus hallucatus was associated more with the structurally simple open‐forest types. Of the two mainly herbivorous species Mesembdomys gouldii showed associations only withfioristics in both seasons, while the habitat relationships of Trichosurus arnhemensis were very weak due to its low abundance in the study area.The number and strength of animal/habitat relationships were greatest in the dry season. Forest types with dense mid‐level foliage and abundant hollow logs and leaf litter had the greatest mammal richness and abundance; these areas may be critical to the survival of local mammal populations.A comparison of site‐groups, defined independently on the basis of fauna, floristics or structure, showed that animal groups overlapped one to six of the habitat groups. The animal's perception of s‘habitat’ may thus differ from that of humans, or that defined by measurement of habitat attributes.
Decomposition and accumulation of litter after fire in sub‐alpine eucalypt forests
Authors: RAISON R. J. , WOODS P. V. , KHANNA P. K. 
Published: July 2006

AbstractAccession, decomposition and accumulation of litter were studied in three sub‐alpine eucalypt forest communities (dominated by overstoreys of Eucalyptus delegatensis, E. pauciflora or E. dives) located in the Brindabella Range. Australian Capital Territory, at an elevation of 1100–1250 m. The sites had either been protected from fire for more than 20 years or been burnt by low‐intensity prescribed fires. After a prescribed burn, the rate of decomposition of abscised leaves was reduced by 22% in E. delegatensis forest and by 34% in E. pauciflora forest, but was little affected in the drier E. dives community. Lowered decomposition was apparently due to greater aridity after fire, a consequence of removal of the shading understorey and reduction in the depth and hence mulching effect of the titter layer. Litter accumulates rapidly after prescribed burning, reaching a mass of 10–12 t ha−1 within 4–5 years in all communities. Such quantities are dangerous from a fire control viewpoint. The quasi steady‐state mass of accumulated litter ranges from about 17 t ha−1 in E. dives and E. pauciflora forests to about 25 t ha−1 in old‐growth E. delegatensis forests. The rapid re‐accumulation of litter after fire is not the result of any significant change in litterfall rate, but is due to a marked reduction in the total amount of litter decomposing—and this reduction is more a consequence of a decrease in the weight of the forest floor than to any fire‐induced lowering of the rate of litter decomposition. The rapid build‐up of litter is a consequence of the relatively high rates of litterfall (3.4–5.0 t ha−1 year−1) and low rates of litter decomposition (k = 0.19–0.32 year−1) in these forests. In most cases the pattern of litter accumulation was well described by an exponential equation of the form Xt= Xss (1—e‐kt), where Xt is the weight (t ha−1) of litter accumulated at time t (year). Xss is the weight of litter accumulated under steady‐state conditions, and k is a decomposition rate constant (year−1). Marked temporal variations in annual litterfall and mass of accumulated litter were found at specific forest sites which had been unburnt for more than 4.5 years. Variation from the long‐term mean was greater for litterfall (31–37%) than for accumulated litter (14–26%). The maximum error when calculating decomposition rate (k) as the ratio of annual litterfall: accumulated titter, when based on single measurements of these parameters, ranged from 43 to 69% of that based on long‐term measurements. Decomposition rates of the entire titter layer, calculated for periods of 22–79 months, and based on measurements of litter input and change in mass of accumulated titter, were positively correlated with the average number of days per month during each period that the litter layer remained moist (>approx. 60% ODW). The implications of these findings for fire management planning in sub‐alpine and other eucalypt forests are briefly discussed.
The effect of fire frequency on the structure and floristic composition of a woodland understorey
Authors: FOX MARILYN D. , FOX BARRY J. 
Published: July 2006

AbstractA long term study site which had not burnt since 1968 was partly burnt in August 1974 and the entire area burnt again in August 1980. The two wildfires, in the same season and with similar intensity, allowed a study of the effect of the frequency component of the fire regime on the floristic composition and structure of a shrubby woodland understorey. In 1982, 2 years after the last fire, that part of the site burnt twice in 12 years had significantly more plant species, higher shrub density and greater cover than that which burnt once only. Of the species found only on the single‐fire part of the site, all were obligate seedling regenerators, while the larger number of species found only on the twice‐burnt part were predominantly vegetative regenerators. The results have implications for vegetation managers: areas burnt too frequently may lose obligate seedling regenerators, while an area remaining unburnt for too long may lose some vegetatively regenerating species, as well as short‐lived obligate seedling regenerators. This highlights the necessity for research in different vegetation types to assess adequately these limits to their ‘natural’ frequencies. Such research would form the basis for informed management decisions.
Dieback of rural eucalypts: Tree phenology and damage caused by leaf‐feeding insects
Authors: LANDSBERG JILL 
Published: July 2006

AbstractDuring three growing seasons, phenology and damage on leafy shoots of healthy eucalypts and others with dieback were monitored on pastoral properties in the Australian Capital Territory. Leaves from the dieback trees tended to be younger than those from nearby healthy trees. Leaves that were not lost prematurely lived for similar lengths of time on both dieback and healthy trees, but more leaves were initiated on the dieback trees. Dieback trees were also less active reproductively. During the study, chewing insects caused most of the damage on leaves, and there was usually more of this damage on leaves from the dieback trees. Young leaves accumulated damage at a much faster rate than older leaves, and this probably contributed to the relatively greater damage on the leaves from the dieback trees. However, the differences in the amount of damage on the leaves from healthy and dieback trees were not solely due to the differences in ages of the leaves. Generalized linear models which equalized the effects of the differences in leafing phenology produced adjusted estimates for damage to leaves that were still higher for dieback trees.
Effect of rainfall on biomass, growth and dieback of pastures in an arid grazing system
Authors: ROBERTSON GRAHAM 
Published: July 2006

AbstractThe influence of rainfall and initial pasture biomass on growth and dieback of pastures in temporary enclosures over quarterly periods was examined from 1980 to 1985 at Menindee in western New South Wales. Rainfall during the previous 12 months had the most influential effect on biomass of grazed pasture, and accounted for 69% of the variance. During quarterly periods, when the biomass of pasture protected from grazing increased, rainfall accounted for 93% of the variance. For all quarterly periods (whether pasture biomass increased or decreased) current rainfall accounted for 72% of the variance in biomass change (growth minus senescence) and initial biomass accounted for a further 14%. The growth response to rainfall was similar in pastures grazed by a combination of sheep and kangaroos and in those grazed by kangaroos alone.
Effects of logging, fire and drought on three species of lizards in Mumbulla State Forest on the south coast of New South Wales
Authors: LUNNEY DANIEL , EBY PEGGY , O'CONNELL MICHAEL 
Published: July 2006

AbstractThe effects of logging on three species of common skinks were estimated from censuses in four age classes of forest: unlogged, just logged, 1‐year logged and 10–15 year regrowth. The effects of topography (ridge and gully) were examined in each age class. Afire in November 1980 occurred fust after the initial census was completed. Another census was taken in December 1980 to assess its immediate effects. Further censuses were carried out each December from 1981 to 1984. An intense drought overlapped from 1980 to 1983 with the census period. Lampropholis guichenoti occurred in about equal numbers in unlogged and recently logged forest, but its numbers were reduced in the 10–15 year regrowth forest. This was attributed to changes in the amount and pattern of sunlight reaching the ground. A similar pattern of response was found for Lampropholis delicata. The numbers of Eulamprus heatwolei, a gully species requiring partial shade, were lowest in the exposed, recently‐logged forest, but had increased in the 10–15 year regrowth class to about equal their numbers in unlogged forest. Fire reduced the numbers ofL. guichenoti on ridges but had no immediate impact on numbers of tire other species, while drought markedly depressed numbers of all species. Lampropholis guichenoti recovered more quickly from the drought than did L. delicata, but the numbers of E. heatwolei were still declining 19 months after the drought broke. The drought also revealed a habitat (ridge/gully) difference between the two Lampropholis species. The management of these species in commercial forests requires that some areas, particularly gullies, be reserved and the logging sequence modified to prevent the creation of widespread stands of uniform regrowth.
Efficacy of primary hormone therapy for localized or locally advanced prostate cancer: results of a 10‐year follow‐up
Authors: AKAZA HIDEYUKI , HOMMA YUKIO , USAMI MICHIYUKI , HIRAO YOSHIHIKO , TSUSHIMA TOMOYASU , OKADA KIYOKI , YOKOYAMA MASAO , OHASHI YASUO , ASO YOSHIO ,   THE PROSTATE CANCER STUDY GROUP
Published: August 2006

OBJECTIVETo evaluate the efficacy of primary hormone therapy for localized or locally advanced prostate cancer, by analysing the 10‐year survival rates for men with localized or locally advanced prostate cancer treated with primary hormone therapy or prostatectomy.PATIENTS AND METHODSBetween February 1993 and March 1995, men with T1b, T1c or T2‐3 N0M0 prostate cancer were enrolled. In all, 176 men who had a prostatectomy were assigned to Study 1 and were given adjuvant luteinizing hormone‐releasing hormone (LHRH) agonist; 151 men who did not have a prostatectomy were assigned to Study 2 and had LHRH agonist monotherapy or combined androgen blockade. They were followed until death, loss to follow‐up, or until the end of the observation period (31 March 2004). We analysed all cases in each study as a single population, and compared Study 1 with Study 2.RESULTSThe mean patient ages were 67.2 years in Study 1 and 75.7 years in Study 2. During a median of 10.4 years of follow‐up, 20 men in Study 1 and 17 in Study 2 died from prostate cancer, and 21 men in Study 1 and 50 in Study 2 died from other causes. In Study 1, the 10‐year overall survival rate was 73% and the 10‐year cause‐specific survival rate was 86%, vs 41% and 78% in Study 2. Overall survival curves were similar to expected survival curves in both studies. There was no significant difference between studies in cause‐specific survival.CONCLUSIONSThe progression of prostate cancer was retarded by primary hormone therapy in men with localized or locally advanced prostate cancer. With primary hormone therapy or prostatectomy, the men had a life‐expectancy similar to that of the normal population.