bluuebunny/crossref_metadata_2025 huggingface dataset:
Least limiting water range: a potential indicator of physical quality of forest soils
Authors: Zou C. , Sands R. , Buchan G. , Hudson I.
Published: January 2006

The interactions of the 4 basic soil physical properties—volumetric
water content, matric potential, soil strength, and air-filled
porosity—were investigated over a range of contrasting textures and for
3 compaction levels of 4 forest soils in New Zealand, using linear and
non-linear regression methods. Relationships among these properties depended
on texture and bulk density. Soil compaction increased volumetric water
contents at field capacity, at wilting point, and at the water contents
associated with restraining soil strength values, but decreased the water
content when air-filled porosity was limiting. The integrated effect of matric
potential, air-filled porosity, and soil strength on plant growth was
described by the single parameter, least limiting water range (LLWR). LLWR
defines a range in soil water content within which plant growth is least
likely to be limited by the availability of water and air in soil and the soil
strength. Soil compaction narrowed or decreased LLWR in most cases. In coarse
sandy soil, initial compaction increased LLWR, but further compaction
decreased LLWR. LLWR is sensitive to variations in forest management practices
and is a potential indicator of soil physical condition for sustainable forest
management.
Preface: Sodicity issues in agricultural industries
Authors: Surapaneni Aravind
Published: January 2006

Australia is recognised as containing the world�s largest area of sodic soils, with
approximately 33% of the continent being affected.
The first National Conference and Workshop on Sodic Soils in Australia was held in
Adelaide (9�13 November 1992), to bring together information and experience on sodic soils
available at that time. The papers from that conference were published as a special issue of
the Australian Journal of Soil Research (Volume 31, 1993). The 1992 conference covered
a wide range of topics, including distribution, classification, mineralogy, fertility,
environmental consequences, irrigation, and management of sodic soils. Importantly, it
identified priority areas for research in each of these topics.
Prediction of the daily number of forest fires
Authors: García Diez E.L. , Soriano L. Rivas , de Pablo F. , García Diez A.
Published: January 2006

On the basis of a qualitative index (Daily
Fire Risk) for the meteorological
severity, a model for predicting the daily number of forest fires over a zone
is developed. DFR is obtained for each day from (e, D)
values, where e is the parameter of stability in the
lowest atmospheric layer (850–700 hPa) and D is
the saturation deficit at lowest level (850 hPa). Both e
and D are evaluated at 00.00 UTC from radwindsonde data.
Four types of day may be described: I, II, III and IV-type if a classification
on (e, D) values is established.
Very High fire activity is associated with type-I days;
High with Type-III; Low with type
IV and Very Low with type-II days. As in the case of
other qualitative indices, two days which present an identical index may
register a very different number of forest fires. This is due to the fact that
the fire activity on a day d does not depend exclusively
upon meteorological parameters of the day d.
A second question to consider is related to the prediction of the daily number
of fires PNF(d). In this way, an initial hypothesis may
be PNF(d) = PW(d) W(d), in which
PW(d) and W(d) are the
Past Weather and the (present)
Weather for each day d. If several
considerations such as PW(d) ≈ PW(d–1) are
introduced, a working expression for the daily number of forest fires results.
The results obtained confirm the utility of the model and, consequently, it
should be used to establish correct antifire management.
Comparative study of various methods of fire danger evaluation in southern Europe
Authors: Viegas D. Xavier , Bovio Giovanni , Ferreira Almerindo , Nosenzo Antonio , Sol Bernard
Published: January 2006

Five methods for the evaluation of fire danger, based on meteorological
factors, were tested using statistical data for daily number of fires and
burned area from six different regions in France, Italy and Portugal, for a
period of 3-9 years, both for Winter and Summer fires. A normalised scale for
the output of the various methods was adopted to compare the variation of
number of fires and burned area predicted by each method. Based on a
statistical test, the relative performance of the various methods is assessed.
From the five methods that were analysed in this research, the Canadian and
the modified Nesterov methods showed the best overall performance.
The mathematical modelling and computer simulation of wildland fire perimeter growth over a 3-dimensional surface
Authors: Richards Gwynfor D.
Published: January 2006

This work considers wildfire growth over variable topography. Through an
analysis of fire perimeter growth for homogeneous conditions over a surface of
constant slope, a mathematical model of fire growth for heterogeneous
conditions and variable surface is proposed. The mathematical model is in the
form of a system of partial differential equations that require a numerical
method of solution. A simple numerical solution technique is described and
example solutions are given for fires over a variety of complex surfaces
illustrating that simulation results can be obtained in reasonable time.
The effect of fire front width on surface fire behaviour
Authors: Wotton B.M. , McAlpine R.S. , Hobbs M.W.
Published: January 2006

To determine the effect of fire front width on surface fire spread rates, a
series of simultaneously ignited experimental fires was carried out in a pine
plantation. Fires were ignited in plots with widths ranging from 0.5 m to 10 m
and were burned in low wind conditions. Flame lengths were small in all fires,
ranging from 20 cm to 60 cm. Since pre-heating of the forest litter from flame
radiation is assumed to be an important mechanism in the spread of low
intensity, low wind surface fires, it then follows that the width of a flaming
front should effect on the heating of the fuel to ignition temperatures. Total
flame radiation was also measured at a point 50 cm ahead of the advancing
flame front for a number of the fires. Experimental results indicate that a
flame radiation measured ahead of the fire stays fairly constant once the
flame width is between 2 and 5 m. Theoretical flame radiation calculations
confirm this trend. Rates of spread between the 5 and 10 metre width fires
also appear to be similar; this indicates that, for the type of fires studied,
once flame width is greater than about 2 m, radiation from any extra width of
fire front has little effect on spread rate.
Physical Modelling of Leaf Scorch Height From Prescribed Fires in Young Eucalyptus Sieberi Regrowth Forests in South-Eastern Australia
Authors: Gould JS , Knight I , Sullivan AL
Published: January 2006

Information on weather, fuel and fire behaviour were recorded on 56 experimental prescribed fires in young coastal silvertop ash (Eucalyptus sieberi) regrowth forest in south-east New South Wales, Australia. The thermal environment above the fire was measured in 14 of those fires. Existing plume models, based on the assumption of a uniformly burning line fire, were found to under-predict the temperature of the air rising into the canopy. An axially symmetric plume model, based on the observation that fires burning in non-uniform fuels are not uniformly burning line fires, was developed using standard plume rise equations. This model, called the Sporadic Axial Model (SAM), was calibrated using data from one fire. This model can be used to predict scorch height from known ambient temperature and Byram's fire line intensity. The SAM model suggests that scorch height will be greater for prescribed fires burnt under calm conditions than prescribed fires of the same intensity burnt under stronger wind conditions.
Prescribed Burning of Thinning Slash in Regrowth Stands of Karri (Eucalyptus diversicolor) .1. Fire Characteristics, Fuel Consumption and Tree Damage
Authors: McCaw WL , Smith RH , Neal JE
Published: January 2006

'Fire characteristics, fuel consumption and fire-caused tree damage were investigated for ten low to moderate intensity fires in thinning slash fuel in 22-year-old karri (Eucalyptus diversicolor F. Muell) regrowth in Western Australia. Eight fires were burnt in spring and two in autumn. Most fires consumed greater than 80 per cent of dead fuel < 25 mm in diameter and between 40 per cent and 80 per cent of the litter layer. The total amount of litter and dead fuel < 100 mm in diameter consumed during burning ranged from 24 to 79 t ha-1 (31-89 per cent). Actual and percentage consumption of fuel < 100 mm diameter were inversely related to the moisture content of the litter profile. Fireline intensities determined from flame length estimates ranged from 90 kW m-1 to 2820 kW m-1. Damage to retained trees included stem wounding, crown death and complete death of the stem. Burning in spring when the litter profile was moist resulted in damage to the lower stems of up to 80 trees ha-1, with damage affecting an average of 3 m2 ha-1 of the retained basal area of 19.5 m2 ha-1. The incidence of stem damage following spring burning was considerably greater when the litter layer was dry. Autumn burning resulted in extensive stem damage and tree mortality and is not therefore recommended. Log debris within 1 m of trees significantly increased the probability of fire-caused damage, and wounds tended to be larger on trees that had debris nearby. The incidence of damage from burning was directly related to the quantity of fuel consumed and heat release per unit area, but was not significantly correlated with fireline intensity. A prescription for burning thinning slash during spring conditions is presented.
Project Aquarius 11. Effects of Fitness, Fatness, Body Size, and Age on the Energy Expenditure, Strain, and Productivity of Men Suppressing Wildland Fires
Authors: Brotherhood JR , Budd GM , Hendrie AL , Jeffery SE , Beasley FA , Costin BP , Zhien W , Baker MM , Cheney NP , Dawson MP
Published: January 2006

Multiple-regression analyses were done to evaluate the effects of aerobic fitness (maximum oxygen uptake per kg fat-free mass), fatness (body fat content, %), body size (as reflected in fat-free mass), and age on the strain (i.e. the physiological and subjective responses) and fireline productivity of four crews of firefighters (N=21) while (1) they undertook 'line rakes', in which they attempted to suppress well-developed experimental bushfires of intensities commonly faced by hand-tool crews, and also built fireline in the same way without fire, during three summers in Australian eucalypt forests; and (2) they underwent the Shvartz heat-tolerance test, which requires 15 minutes of step-climbing at a fixed pace in a room temperature of 23°C. The results showed that the expected effects of fitness and fatness, established through laboratory studies and confirmed in the Shvartz test, were attenuated or absent during the line rakes, apparently because of self pacing and the absence of rapid climbing. In the line rakes fitter men did not work harder than the less fit but were more productive and efficient and had somewhat lower heart rates; fatter men tended to be more productive than leaner men but did not experience greater strain; bigger men (as measured by fat-free mass) were more productive than smaller men; age had no effect on strain or productivity; and associations observed during work in both the line rakes and the Shvartz test were already present before the work commenced, apparently because of emotional arousal. Responses in the Shvartz test (including the heat-tolerance score) were uncorrelated with their counterparts in the line rakes, emphasising the limited application of laboratory findings to normal fire-suppression duties. Productivity and efficiency in timed trials of firefighters' line-building performance were uncorrelated with their counterparts during the line rakes. We conclude that the adverse effects of fatness or low aerobic fitness are minimized by work practices that allow firefighters to adjust their own pace, but will become apparent whenever the pace is fixed, the terrain is steep, or some emergency calls for sustained maximal effort.
Project Aquarius 12. Effects of Style, Fabric, and Flame-Retardant Treatment on the Effectiveness and Acceptability of Wildland Firefighters' Clothing
Authors: Budd GM , Brotherhood JR , Hendrie AL , Jeffery SE , Beasley FA , Costin BP , Zhien W , Baker MM , Cheney NP , Dawson MP
Published: January 2006

Balanced comparisons, using a crossover experimental design, were made of the effectiveness and acceptability of several commonly-worn clothing outfits during three summers in Australian eucalypt forests. The wearers were four crews who attempted to suppress well-developed experimental bushfires of intensities commonly faced by hand-tool crews, and also built fireline in the same way without fire. Parallel comparisons were made on the clothing worn by 6 male scientific observers, who shared the same environment but did lighter work. The outfits differed mainly in style (coveralls vs. shirt and trousers), fabric (wool vs. cotton), and flame-retardant treatment ('Proban'-treated vs. untreated cotton coveralls). Analyses of variance showed that there were no significant differences between clothing outfits in the wearers' work rate, physiological strain, discomfort, productivity, or efficiency. The findings did not differ between crews or summers, nor between fireline construction with and without fire. Because all outfits were equally effective and acceptable, other considerations - such as durability, cost, appearance, and personal preference - can be given their due weight when choosing between them.
Wildland Fire Patch Dynamics in the Chaparral of Southern California and Northern Baja California
Authors: Minnich RA , Chou YH
Published: January 2006

In ecosystems where fire occurrence has significant time-dependence, fire sequences should exhibit system-regulation that is distinguished by nonrandom (nonstationary), self-organizing patch dynamics related to spatially constrained fire probabilities. Exogenous factors such as fire weather, precipitation variability, and terrain alter the flammability of vegetation and encourage randomness in fire occurrence within pre-existing patch structure. In Californian chaparral, the roles of succession/fuel build-up and exogenous factors is examined by taking advantage of a 100 yr 'natural experiment' in southern California (SCA) and northern Baja California, Mexico (BCA), where factors influencing fire occurrence have been systematically altered by divergent management systems. In SCA, suppression has been practiced since 1900. In BCA, fire control was not official policy until the 1960s and has not been effectively practiced. Fire perimeter histories for 1920-1971 in SCA and BCA, reconstructed from fire history records and repeat aerial photographs, are compared for fire frequency (events/area), size, rotation periods, stand age structure, ignition rates, weather, burning season, and drought. Landscape-scale fire rotation periods are long (≈70 yr) regardless of management policies because fire occurrence is driven by the gradual development of fire hazard during succession, produced by small annual increments of growth and litterfall, as well as by high fuel moisture in evergreen shrubs. Without fire control frequent fires establish fine-grained mosaics. Fire control reduces fire frequencies, increases fire size, and encourages coarse-scale patch structure. Patch dynamics exhibit evidences of nonrandom turnover. Fire size distributions reflect the nearest-neighbor distances between patches below some age-dependent combustion threshold (CT) in the patch mosaic that resist the spread of fires in stands older than CT. Regional burn rates are poorly related to fire frequency, ignition rates, drought, and terrain. The small size of fires in BCA may be reinforced by interactions between fire and pre-existing, fine-grained patch structure, and by random fire occurrence in the probability distributions of fire weather and climate. In SCA, fires are nonrandomly restricted by fire control to extreme weather.
Land Zoning Based on Fire History
Authors: Bovio G , Camia A
Published: January 2006

An approach to land zoning for fire planning purposes through classification of geographical units referred to as Basic Units - in a multivariate context is proposed. The method, developed for large areas, employs a few statistics computed from historical fire data, that were selected with the aim of depicting a ''fire history profile'' of each Basic Unit. The statistics were chosen in order to describe different aspects, such as fire frequency, fire continuity, average and maximum area burned and average area spread rate of fires. Using the computed statistics as variables, the Basic Units can be aggregated with cluster analysis techniques and classes can be defined, each class of Basic Units representing a land zone with a specific mean fire history profile. Fire management decisions can be tailored according to the properties of clusters. The method was successfully applied for supporting fire management plans in two Regions of Northern Italy, where the Basic Units were chosen with an administrative criterion.
Instantaneous and Automatic Identification of Weather Types for a Forest Fire Decision Support System
Authors: Carrega P
Published: January 2006

The objective of this study, carried out as part of a European Union Contract, was to elaborate an aid package that enables automatic and 'real time' identification of the instantaneous weather situation during seasons with high forest fire hazards. The weather types are defined on the basis of discrimination between the breeze and synoptic wind regimes established from a network of 21 automatic sensors installed in the southeastern extremity of France. The establishment of rules such as: if at station X the wind is from a direction of 100-140° and blows at 2 to 5 m/s; and if, etc..., then the situation is such — enables, in a logic of artificial intelligence, the proposal of a 'symbolical', 'analog' model of the weather behaviours to be expected over a given area.
Prediction of Fire Spread in Grasslands
Authors: Cheney NP , Gould JS , Catchpole WR
Published: January 2006

This pager describes a model to predict fire spread in grasslands from wind speed at 10 m, dead fuel moisture, and degree of grass curing in three defined pasture types, The model was developed from spread measurements of experimental fins that were adjusted to their potential rate of spread at wide fronts. Extrapolations of the model were compared with spread data from 20 major wildfires in Australia. This model uses different functions to describe the relationship between rate of spread and wind speed above and below a critical wind speed of 5 km h-1. A linear relationship is used below 5 km h-1; above 5 km h-1 rate of spread is described by a power function of wind speed with an exponent of less than 1.
Reduction of Fire Hazard Through Thinning/Residue Disposal in the Urban Interface
Authors: Kalabokidis KD , Omi PN
Published: January 2006

Alternative fire hazard reduction techniques are needed for managing fuel profiles in forest ecosystems located within the so-called wildland-urban interface. The present study includes experimental fuel manipulations initiated along the Rocky Mountain National Park interface with residential areas in Colorado, USA. Three thinning/slash disposal treatments were applied on two lodgepole pine (Pinus contorta) stands: thinning with whole-tree removal; thinning with stem removal - lopping and scattering; and thinning with stem removal - hand piling and burning. Results indicate that treatments reduced surface fire behavior parameters, bringing them down and closer to Limits of direct attack methods. Crown fire potential was decreased not only because of canopy removal, but also as a result of potential reduction in heat generated by surface fuels. Projected fire behavior for the thinning-without-slash-removal scenario indicates the possibility of serious control problems with major fire runs and crown fires given an outbreak.
Seventeen Years of Forest Succession Following the Waterfalls Canyon Fire in Grand Teton National Park, Wyoming
Authors: Doyle KM , Knight DH , Taylor DL , Barmore WJ , Benedict JM
Published: January 2006

Plant species composition has been sampled periodically since the 1974 Waterfalls Canyon Fire in Grand Teton National Park, Wyoming. Prior to the fire, the forests were dominated by mature Abies lasiocarpa, Picea engelmannii and Finns contorta. All three tree species have reestablished. After 17 years, P. engelmannii sapling density was 1.2-11.2 times greater than the other tree species. A. lasiocarpa and P. contorta saplings were second in density to P. engelmannii in the moderate and severely burned stands, respectively. The understory shrub and herbaceous species that were most abundant during the first 17 years were common the first year after the fire and were also found in the unburned mature forest. Species present in the unburned forest contributed 91-100% of the understory cover in the moderate burn, and 55-74% in the severe burn. Species richness was greatest in the severely burned stand and has increased during the 17 years of succession. While sprouting is the primary mechanism for understory plant establishment in the moderate burn, most species appear to have grown from seeds in the severe burn.
The Influence of Wildfire on Aqueous-Extractable Soil Solutes in Forested and Wet Meadow Ecosystems Along the Eastern Front of the Sierra-Nevada Range, California
Authors: Blank RR , Zamudio DC
Published: January 2006

Information is lacking regarding the influence of pre-fire microsite conditions on post-wildfire soil chemical properties. Following a 1994 wildfire along the eastern front of the Sierra Nevada range, California, high performance ion exchange chromatography was used to quantify anions and cations in aqueous soil extracts by plant microsite (Pinus jeffreyi subcanopy, Calocedrus decurrens subcanopy, Carer microptera meadow, Salix scouleriana subcanopy), by depth (ash or litter, mineral soil horizon 0-5 cm), and by treatment (unburned, burned). As compared to the unburned treatment, post-wildfire ash and surface mineral horizons had significantly (P less than or equal to 0.05) higher concentrations of sodium, magnesium, formate, and chloride. Plant microsite interacted significantly with treatment for ammonium; all plant microsites had significantly higher ammonium in burned treatments and burned S. scouleriana and C. microptera microsites had significantly more ammonium than the C. decurrens or P. jeffreyi microsites. For pH and acetate there was a significant treatment × depth interaction in which concentrations were highest in burned ash layers. For sulfate, ortho-phosphate, and calcium, there was a significant plant microsite × treatment × depth interaction. In general, post-wildfire ash and soil mineral layers had significantly more sulfate and calcium than the unburned controls; ash layers contained significantly less ortho-phosphate than unburned litter layers. There was a significant treatment × depth interaction for magnesium, chloride, formate, acetate, potassium, and nitrate. Initial post-wildfire levels of short-chained aliphatic carboxylic acids were very high, especially in ash layers, and did not decline to preburn values by the following summer.
Heat Flow Measurements From Smoldering Porous Fuel
Authors: Frandsen WH
Published: January 2006

A stirred water calorimeter measured the total downward heat load beneath a simulated smoldering organic soil horizon of peat moss. Moisture and inorganic ratios (fraction of water and inorganic contents relative to organic dry mass) of the peat moss ranged from 0 to 0.6 and near 0 to 4 respectively. Feat moss was packed to organic hulk densities of 90 kg m-3 and 120 kg m-3 at depths of 2 cm, 4 cm, and 6 cm. Total heat load was recorded over the range of conditions given above. Data were analyzed by stepwise multiple linear regression. Measured heat loads were within the range of 10 MJ m-2 to 100 MJ m-2. The heat load increased nonlinearly with increasing inorganic ratio and decreased linearly with increasing moisture ratio. The heat load is linear with depth holding the organic hulk density and the moisture and inorganic ratios constant.
Phosphorus and Nitrogen Dynamics in Streams Associated With Wildfire: a Study of Immediate and Longterm Effects
Authors: Hauer FR , Spencer CN
Published: January 2006

Stream nutrient data were collected both during a wildfire and over a subsequent five-year period. Sampling was from a series of paired watersheds located within and outside of the wildfire. Phosphorus and nitrogen concentrations increased from 5 to 60 fold over background levels during the first few days of the month-long wildfire with maximum recorded concentrations as high as 135 μg/L soluble reactive phosphorus, 261 μg/L ammonium, and 61 μg/L nitrate. Total phosphorus and total nitrogen during this same time period increased up to 206 μg/L and 349 mμg/L, respectively. Nutrient concentrations declined to background levels (<5-10 μg/L) within a few weeks after the fire. Over the following five years we observed dissolved nutrient concentrations reaching >40 μg/L soluble reactive phosphorus and >125 μg/L nitrate in impacted streams, concentrations >5 fold over those observed in control streams. In high gradient watersheds, all nutrients were easily transported to the streams with most notable impact during the early years after the fire. In less steep terrain, soluble reactive phosphorus concentrations were significantly higher 3 to 5 years after the fire, which also corresponded to relatively high spring hydrographs. In contrast, nitrogen compounds were observed to be significantly higher in concentration in fire impact streams in the years immediately following the fire. We attribute these differences in the rate of nutrient loads to be the result of the different mobilization mechanisms of phosphorus and nitrogen and the different soil and geomorphic settings of the watersheds drained by the different streams.
An Economic Evaluation of Public and Organized Wildfire Detection in Wisconsin
Authors: Steele TW , Stier JC
Published: January 2006

Early detection is the first step toward effective wildfire control. This study used cost-benefit techniques to evaluate the economic efficiency of fixed lookouts for wildfire detection in Wisconsin. Costs and benefits were assessed relative to a baseline scenario of public detection alone. Analyses revealed that fixed lookouts were economically efficient in aggregate; however, their performance varied considerably among administrative areas and among lookouts. Twenty-five percent of the fixed lookouts detected the majority of wildfires and accounted for virtually all suppression cost savings and property damage prevention. Additional analyses showed that fixed lookouts and the public saw wildfire that were significantly different. Specifically, the public tended to detect wildfires in developed areas at a relatively early stage, whereas fixed lookouts spotted fires in more remote, sparsely populated regions. These findings suggest that opportunities exist to enhance wildfire detection efficiency and cost effectiveness by selectively adjusting lookout use.
A Study on the Interpolation of Fire Danger Using Radar Precipitation Estimates
Authors: Flannigan MD , Wotton BM , Ziga S
Published: January 2006

In Canada, many fire management agencies interpolate indexes of the Fire Weather Index System to estimate the fire danger between weather stations. Difficulties with interpolation arise because summer precipitation can be highly variable over short distances. This variability hinders the usefulness of interpolating precipitation, which is one of the inputs for the Fire Weather Index System. Precipitation estimates from the Canadian Atmospheric Environment Service radar at Upsala, Ontario, were used to determine if this will enable a more accurate measure of the fire danger over the region. Three methods of interpolation of the fire danger between weather stations were compared: first, the standard practice of interpolating fire weather indexes from weather stations to any specified location; second, interpolating the weather variables, temperature, relative humidity, wind speed and precipitation from the weather station to any specified site and then calculating the fire weather indexes; third, interpolating weather variables as in Method 2 above except using the precipitation estimate from the radar and then calculating the fire weather indexes for any specified site. Overall, results indicate that the standard procedure of interpolating the fire weather indexes performs better than the other two methods. However, there are indexes where the other methods perform best (e.g., the fine fuel moisture code is best determined by using the radar precipitation estimation method). Fire management agencies should continue to use the standard practice of interpolating fire weather indexes to estimate fire danger between weather stations. Factors influencing the performance of the radar estimated precipitation method of estimating fire danger are discussed along with potential application of precipitation radar for fire management purposes.
Rabbit haemorrhagic disease in New Zealand: field test of a disease - host model
Authors: Barlow N. D. , Barron M. C. , Parkes J.
Published: January 2006

An earlier published model, parameterised from qualitative data from Europe and detailed observations of the first simple epidemic in Australia, gave a good fit to longer-term (3 year) data from New Zealand, without any re-tuning of parameters. Changing some of the unknown disease parameters further improved the model's fit, but two problems remained. Firstly, predicted proportions seropositive are too high if rabbit densities are as low as observed, and if the proportions seropositive are correct then the predicted densities are too high. Secondly, observed rabbit densities do not show obvious peaks of recruitment, as predicted by the model with and without RHD. Possible reasons for these discrepancies are suggested, and initial trials with the model suggested that a novel transmission mechanism involving both direct (rabbit to rabbit) and indirect (via free-living virus) transmission may help explain both high suppression and low antibody levels. The main conclusions from the original model remain unaffected by its testing against new data, namely: rabbit populations are likely to be suppressed in the long term by about 75%; the pattern of epidemics is determined largely by intrinsic disease behaviour rather than seasonality, though the latter may tune this to some extent; there tend to be yearly epidemics; percentages of rabbits infected at any one time are low (around 5%) but this does not imply low impact; maternal antibodies have little effect on RHD dynamics; RHD may persist in low-density as well as high-density populations but give less suppression; and additional control may eradicate disease, at least temporarily.
Macropod studies at Wallaby Creek. X. Responses of eastern grey kangaroos to cattle
Authors: Payne Alison L. , Jarman Peter J.
Published: January 2006

The instantaneous behavioural and spatial responses of eastern grey kangaroos
to the presence of cattle were studied at Wallaby Creek, north-eastern New
South Wales. Kangaroo groups were distributed closer to cattle groups than
would be expected by chance, both at a study-site scale (154-ha) and at a 1-ha
scale; large males were recorded on average further from cattle than were
smaller males. Nearest-neighbouring kangaroo groups were located such that
cattle groups rarely interrupted the lines of sight between them. Observed
disturbance and displacement by cattle provoked a minimal response in
kangaroos, which fled only tens of metres and soon resumed their previous
activity. The presence of cattle had few detectable instantaneous effects on
the behaviour of the kangaroos, except to increase their alertness and the
feeding time of small (but not large) kangaroo groups. These effects indicate
that cattle pose little threat to kangaroos.
Secondary poisoning of ferrets and cats after 1080 rabbit poisoning
Authors: Heyward Richard P. , Norbury Grant L.
Published: January 2006

The incidence of secondary poisoning was determined by using radio-telemetry
to assess the survival of 68 ferrets and 21 cats on two treatment sites and
one control site in the dry tussock grasslands of New Zealand. The treatment
sites were aerially poisoned with 1080-coated carrot baits (0.02%
wt/wt) to control rabbits. The control site was not poisoned. Ferrets and
cats were monitored at two-weekly intervals for at least 1 month before, and 2
months after the poison operations. Muscle samples from ferrets and cats that
died within 50 days of poisoning on the treatment sites were assayed for 1080.
In all, 7–11% (n = 28) of ferrets on one site and
8–15% (n = 26) of ferrets at the other site apparently
died of secondary 1080 poisoning. Natural mortality rates of ferrets were
46–81% per annum. While we have evidence that secondary poisoning
of cats does occur, we monitored insufficient numbers of cats to reliably
estimate mortality rates.
Declines in predator numbers are commonly observed after rabbit poisoning.
This study indicates that secondary poisoning contributes to these declines.
Movements, dens and feeding behaviour of the tropical scaly-tailed possum (Wyulda squamicaudata)
Authors: Runcie Myfanwy J.
Published: January 2006

I used trapping and radio-telemetry to study a population of scaly-tailed
possums (Wyulda squamicaudata) in the Kimberley region
of Western Australia. Radio-tracking of five adults over eight days provided
detailed information on dens, and on size and shape of the home range, and
facilitated nocturnal observations. W. squamicaudata
used four different types of rock formations for diurnal dens: rockpiles,
sunken rockpiles, large rock slabs and underground rock crevices. Radio-tagged
possums of both sexes nested alone, used multiple dens and had overlapping
home ranges. Both tagged and untagged possums appeared to be solitary and
foraged alone. The average size of the home range was 1.0 ha (range
0.03–2.0 ha). Estimates of density ranged from 2.3 to 4.6 possums per
hectare. Scaly-tailed possums fed on leaves of four species of trees
(Xanthostemon eucalyptoides,
X. paradoxus, Eucalyptus spp., and
Planchonia careya) as well as the flowers and seeds of a
perennial herb (Trachymere didiscordis). Feeding in
trees is aided by the rough scaly tail, which sometimes supports the
possum’s full body weight. At this study site
W. squamicaudata is sympatric with the rock-haunting
possum (Petropseudes dahli), and they may compete for
food and den resources.
Responses of free-ranging brownsnakes (Pseudonaja textilis : Elapidae) to encounters with humans
Authors: Whitaker P. B. , Shine R.
Published: January 2006

Eastern brownsnakes (Pseudonaja textilis) are large (to
2 m), slender, dangerously venomous elapid snakes that cause significant human
mortality. We recorded the responses of free-ranging brownsnakes to 455 close
encounters with a human observer, using 40 snakes implanted with miniature
radio-transmitters, plus encounters with non-telemetered animals. Our study
area (near Leeton in south-eastern Australia) is typical of many of the
agricultural landscapes occupied by P. textilis.
Contrary to public opinion, the snakes were rarely aggressive. About half of
the encounters resulted in the snake retreating, and on most other occasions
they relied on crypsis. Snakes advanced towards the observer on only 12
occasions (<3% of encounters) during initial approach, and only
three of these advances were offensive. The snakes’ responses to an
approach depended on the observer’s appearance (e.g. snakes were more
likely to ignore an observer wearing light rather than dark shades of
clothing) and behaviour (e.g. snakes were more likely to advance if approached
rapidly, and touched immediately). Snakes were more likely to retreat if they
were sub-adult rather than adult, if they were warm, or if they had been
moving prior to an encounter. Weather conditions (air temperature, wind
velocity and cloud cover) also influenced the snakes’ responses, as did
season and time of day. The snakes’ response was relatively predictable
from information on these factors, enabling us to suggest ways in which people
can reduce the incidence of potentially fatal encounters with brownsnakes.
‘Snakes are first cowards, next bluffers, and last of all
warriors’ (Pope 1958)
The impact of cats and foxes on the small vertebrate fauna of Heirisson Prong, Western Australia. I. Exploring potential impact using diet analysis
Authors: Short Jeff , Calver Michael C. , Risbey Danielle A.
Published: January 2006

The diets of cats (Felis catus) and foxes
(Vulpes vulpes) killed during predator control at a
semi-arid site in Western Australia were studied to see which prey species may
be affected by predation from these introduced predators. The number of items,
biomass and frequency of occurrence of each food type in the gut contents from
109 feral cats, 62 semi-feral cats and 47 foxes were used to calculate an
Index of Relative Importance for each food category for each predator. Mammals
were the most important prey group for all three predators, with rabbit being
the most highly ranked prey species. The diets of feral and semi-feral cats
were similar in dietary diversity but differed in the frequency of occurrence
of some food categories. Native rodents, birds and reptiles occurred more
frequently and were ranked higher in the diet of feral cats, and food scraps
occurred more frequently in the diet of semi-feral cats. The diet of foxes was
less diverse than that of either group of cats. Invertebrates and sheep
carrion were more important prey categories for foxes than for cats. In the
summer–autumn period, foxes ate more sheep carrion and invertebrates
than they did in winter–spring. The diet of feral cats was more diverse
in summer–autumn, including a greater range of invertebrates and more
rodents, birds and reptiles than in the winter–spring period. We predict
that cats are more likely to have an impact on small vertebrates at this site
and that the control of cats could lead to recoveries in the populations of
native rodents, birds and reptiles. By contrast, the control of foxes alone
may lead to a rise in cat numbers and a consequent detrimental impact on small
vertebrate populations.
Aerial and ground survey of sap trees of the yellow-bellied glider (Petaurus australis reginae) near Atherton, North Queensland
Authors: Bradford M. G. , Harrington G. N.
Published: January 2006

Sap-feed trees of the yellow-bellied glider
(Petaurus australis reginae) were located in a 1600-ha
site in north Queensland by aerial survey and ground survey. The ground survey
located 77 active sap-feed trees, of which only seven were seen from the
air.Thus we conclude that aerial survey is not a reliable means of censusing
yellow-bellied glider populations. Sap-feeding scars made by gliders were
found only on Eucalyptus resinifera even though four
other species of Eucalyptus, which are used for
sap-feeding in New South Wales, were also present in the area.In addition to
the active feed trees, we found 156 trees with old sap-feeding scars, giving a
total of 233 scarred trees in all.All but two of these were located within 500
m of mature E. grandis trees, which are believed to be
the prime source of glider dens.Of the E. resinifera
trees with diameter at breast height greater than 40 cm in the study area
1.06% were scarred and 0.35% were in active use by the
gliders.The sap-feed trees had significantly fewer other trees in their
immediate vicinity than the mean for all E. resinifera
trees in the study area.The early stages of rainforest invasion investigated
here did not indicate a reduction in use for sap-feeding by gliders.However,
in the long-term E. resinifera is unable to thrive or
reproduce within a rainforest, suggesting that the gliders’ habitat will
be reduced as the E. resinifera trees die out.
Morphology and molecules conflict to confound species boundaries in salt lake ostracodes of the genus Mytilocypris (Crustacea : Ostracoda)
Authors: Finston Terrie
Published: January 2006

The ostracode genus Mytilocypris comprises eight
species, and has a widespread distribution in saline habitats of semi-arid
Australia. Fifteen populations, representing all eight species in the genus,
were analysed at 19 enzyme loci to identify markers to delineate species
boundaries. Only five distinct genetic groups were found:
M. mytiloides, M. ambiguosa,
M. splendida, M. praenuncia, and
M. henricae. Three presumptive species,
M. mytiloides,
M. tasmanica chapmani, and
M. minuta have sympatric distributions in Western
Australia. The three show similar internal morphology, lack any diagnostic
features of colour, pattern or setation of the shell, but differ in the size
and shape of the shell. They also show microhabitat divisions along a salinity
gradient. There were no genetic markers to distinguish the three Western
Australian species from one another, and they showed high genetic similarity
to a population of M. mytiloides from near its type
locality in South Australia. Furthermore, seven populations containing more
than one species in the mytiloides complex failed to show evidence of
reproductive isolation between species, when tested for genetic
differentiation. In contrast, a multivariate analysis, used to quantify and
evaluate patterns of variation within and among the three species in the
mytiloides complex, revealed differences in size, shape and allometry among
species, but also showed overlap of body shapes and sizes of individuals. Two
explanations are plausible for the lack of congruence between morphological
and allozyme data: the three may be closely related species with undetected
genetic differentiation, or the three taxa may be conspecific, and shell size,
shape and allometry may be plastic characters. The role of fluctuating
environmental conditions on crustacean morphology and life history variation
is discussed.
Energy metabolism in an obligate frugivore, the superb fruit-dove (Ptilinopus superbus)
Authors: Schleucher Elke
Published: January 2006

Ptilinopus superbus (body mass 120.4 5.2 g) is a highly
specialised, migratory avian frugivore that is widespread in the rainforests
of the Indo-Pacific Region and north-eastern Australia. The effect of the
specialised diet on metabolic rate (MR) and body temperature
(Tb) were investigated at ambient temperatures
(Ta) of 13-30ºC in activity (α) and rest
(ρ) phases. At thermoneutrality (Ta =
26ºC), the basal metabolic rate (BMR) was 23.2 4.49 J
g-1 h-1 , which corresponds
closely to the predicted value (22.6 J g-1
h-1). Wet thermal conductance
(Cwet) was 2.39 0.45 J g-1
h-1 ºC-1 in α and 1.75
0.13 J g-1 h-1
ºC-1 in ρ for Ta between
13 and 21ºC. These conductances are higher than expected (α: 1.87 J
g-1 h-1
ºC-1; ρ: 1.16 J g-1
h-1 ºC-1) for a non-passerine
bird of this body mass (M), indicating poor insulation of this tropical
species. Tb was 39.6 0.76ºC in α and 38.1
0.55ºC in ρ in the observed Ta range,
corresponding closely to expected values (40.9 1.35 in α and 38.6 0.66
in ρ). This study shows no evidence of an influence of the fruit diet on
the metabolic physiology of superb fruit doves. Analysis of BMR data for all
pigeon species sampled so far provides no evidence that a low basal metabolic
rate is a general characteristic of the Columbidae.
Foraging behaviour and the risk of predation in the black house spider, Badumna insignis (Desidae)
Authors: Henderson Robbie J. , Elgar Mark A.
Published: January 2006

Many animals adjust their behaviour according to the presence or threat of
predators. However, the foraging behaviour of sit-and-wait predators is
typically thought to be inflexible to short-term changes in the environment.
Here we investigate the foraging behaviour of the nocturnally active black
house spider, Badumna insignis. Experiments in which
different kinds of prey were introduced into the web during either the day or
night indicated that the foraging success of Badumna is
compromised by behaviours that reduce the risk of predation. During the day,
spiders generally remain within the retreat and take longer to reach the prey,
which may reduce their foraging success. In contrast, spiders sat exposed at
the edge of the retreat at night, and from here could usually reach the prey
before it escaped. The spiders were able to escape from a model predator more
rapidly if they were at the edge of the retreat than if they were out on the
web. These data suggest that the costs to Badumna of
reduced fecundity through poor foraging efficiency may be outweighed by the
benefits of reducing the risk of predation
Perception of terrestrial and aerial alarm calls by honeyeaters and falcons
Authors: Wood Sharon R. , Sanderson Ken J. , Evans Christopher S.
Published: January 2006

This study tested the responses to aerial and terrestrial alarm and distress
calls in an avian predator, the brown falcon,
Falco berigora, and two potential avian prey species,
the New Holland honeyeater,
Philidonyris novaehollandiae, and noisy miner,
Manorina melanocephala. Calls were delivered from a
computer system at intensities 5–20 dB above background, to birds held
in large cages. All birds located the broad-band alarm and distress calls
easily, but they had difficulty locating the narrow-band aerial alarm calls,
although they were able to detect most of these. Aerial alarm calls thus
reduce risk to the caller. The performance of raptors and songbirds was
similar. This result suggests that there are no reliable differences in the
auditory characteristics of avian predators and prey, as have been described
in species from the Northern Hemisphere.
The systematic status of earless dragon lizards, Tympanocryptis (Reptilia:Agamidae), in south-eastern Australia
Authors: Smith W. J. S. , Osborne W. S. , Donnellan S. C. , Cooper P. D.
Published: January 2006

The systematic status of the dragon lizards
Tympanocryptis lineata pinguicolla and
T. tetraporophora (Agamidae) was examined by allozyme
electrophoresis and multivariate morphological techniques. Both taxa exhibited
considerable genetic and morphological differentiation from each other and
from most other members of the T. lineata species group
examined. The recognition of T. tetraporophora at the
specific level is confirmed and T. l. pinguicolla is
raised to full specific status. The remaining subspecies of
T. lineata are each genetically well differentiated from
each other and may represent full species. Allozyme analysis of specimens from
the T. cephalus/intima complex in eastern Australia
was problematic because of small samples and heterogenous distributions of
alleles, a more extensive sampling being required to resolve their status. A
key is provided for identification of species of
Tympanocryptis in south-eastern Australia.