Journal articles on the topic 'Fire ecology Australia, Southern'
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1
Russell-Smith, Jeremy, Cameron P. Yates, Peter J. Whitehead, Richard Smith, Ron Craig, Grant E. Allan, Richard Thackway, et al. "Bushfires 'down under': patterns and implications of contemporary Australian landscape burning." International Journal of Wildland Fire 16, no. 4 (2007): 361. http://dx.doi.org/10.1071/wf07018.
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Australia is among the most fire-prone of continents. While national fire management policy is focused on irregular and comparatively smaller fires in densely settled southern Australia, this comprehensive assessment of continental-scale fire patterning (1997–2005) derived from ~1 km2 Advanced Very High Resolution Radiometer (AVHRR) imagery shows that fire activity occurs predominantly in the savanna landscapes of monsoonal northern Australia. Statistical models that relate the distribution of large fires to a variety of biophysical variables show that, at the continental scale, rainfall seasonality substantially explains fire patterning. Modelling results, together with data concerning seasonal lightning incidence, implicate the importance of anthropogenic ignition sources, especially in the northern wet–dry tropics and arid Australia, for a substantial component of recurrent fire extent. Contemporary patterns differ markedly from those under Aboriginal occupancy, are causing significant impacts on biodiversity, and, under current patterns of human population distribution, land use, national policy and climate change scenarios, are likely to prevail, if not intensify, for decades to come. Implications of greenhouse gas emissions from savanna burning, especially seasonal emissions of CO2, are poorly understood and contribute to important underestimation of the significance of savanna emissions both in Australian and probably in international greenhouse gas inventories. A significant challenge for Australia is to address annual fire extent in fire-prone Australian savannas.
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Penman, T. D., and B. A. Cirulis. "Cost effectiveness of fire management strategies in southern Australia." International Journal of Wildland Fire 29, no. 5 (2020): 427. http://dx.doi.org/10.1071/wf18128.
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Fire-management agencies invest significant resources to reduce the impacts of future fires. There has been increasing public scrutiny over how agencies allocate fire-management budgets and, in response, agencies are looking to use quantitative risk-based approaches to make decisions about expenditure in a more transparent manner. Advances in fire-simulation software and computing capacity of fire-agency staff have meant that fire simulators have been increasingly used for quantitative fire-risk analysis. Here we analyse the cost trade-offs of future fire management in the Australian Capital Territory (ACT) and surrounding areas by combining fire simulation with Bayesian Decision Networks. We compare potential future-management approaches considering prescribed burning, suppression and fire exclusion. These data combined costs of treatment and impacts on assets to undertake a quantitative risk analysis. The proposed approach for fuel treatment in ACT and New South Wales (NSW) provided the greatest reduction in risk and the most cost-effective approach to managing fuels in this landscape. Past management decisions have reduced risk in the landscape and the legacy of these treatments will last for at least 3 years. However, an absence of burning will result in an increased risk from fire in this landscape.
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Hill, Robert S., Yelarney K. Beer, Kathryn E. Hill, Elizabeth Maciunas, Myall A. Tarran, and Carmine C. Wainman. "Evolution of the eucalypts – an interpretation from the macrofossil record." Australian Journal of Botany 64, no. 8 (2016): 600. http://dx.doi.org/10.1071/bt16117.
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Eucalypts have influenced the fire ecology of the Australian landscape more than any other plant group. They are the iconic plant taxon in the Australian vegetation today, but their origin, early evolution and migration remain poorly understood, mostly because of a remarkably sparse and underworked fossil record. However, a recent major macrofossil find in southern South America, coupled with increasing sophistication of molecular phylogenetic and palynological research allow for a more comprehensive summary of the likely early history of this group of genera. It is likely that the origin was close to the Cretaceous–Paleogene boundary, somewhere in the Weddellian Biogeographic Province (which includes southern South America, western Antarctica and south-eastern Australia), in an area with high natural fire frequency. Evidence for the early record of eucalypts in Australia and their eventual spread across the continent, leading to their current dominance of the Australian plant biomass is growing and is consistent with a drying climate and increasing fire frequency following a very wet period during the Paleogene. The causes of the extinction of eucalypts from South America and probably New Zealand are considered, but remain obscure.
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Plucinski, M. P., A. L. Sullivan, and W. L. McCaw. "Comparing the performance of daily forest fire danger summary metrics for estimating fire activity in southern Australian forests." International Journal of Wildland Fire 29, no. 10 (2020): 926. http://dx.doi.org/10.1071/wf19185.
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Fire danger indices integrate weather and fuel variables to indicate the potential for wildland fires to ignite, spread, resist suppression and cause damage. McArthur’s Forest Fire Danger Index (FFDI) is applied across much of Australia, with the forecast daily maximum value used to inform fire management planning decisions and issuance of public warnings. Variations in daily maximum FFDI and the hourly changing of FFDI values during the day (including use of different soil moisture deficit indices) were compared against five binary fire activity statistics in six forested areas in southern Australia, with performance assessed using Theil–Sen regression lines fitted to rank percentile curves. Fire activity rates were similar on days with wide and narrow hourly FFDI distributions except in one study area where days with wide distributions experienced more fires. The maximum hourly FFDI metric performed the best of all the metrics tested, though there were no statistically significant differences among any of them. There was also little difference in the performance of metrics determined using alternative calculations and different drought indices. These results suggest that the current use of the forecast hourly maximum FFDI is appropriate and that using alternative methods to determine Drought Factor offers little benefit.
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Cook, Garry D., Adam C. Liedloff, C. P. (Mick) Meyer, Anna E. Richards, and Steven G. Bray. "Standing dead trees contribute significantly to carbon budgets in Australian savannas." International Journal of Wildland Fire 29, no. 3 (2020): 215. http://dx.doi.org/10.1071/wf19092.
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Previous estimates of greenhouse gas emissions from Australian savanna fires have incorporated on-ground dead wood but ignored standing dead trees. However, research from eucalypt woodlands in southern Queensland has shown that the two pools of dead wood burn at similar rates. New field data from semiarid savannas across northern Australia confirmed that standing dead trees comprise about four times the mass of on-ground dead wood. Further, the proportion of total woody biomass comprising dead wood increases with decreasing fire frequency and a decreasing proportion of late dry season (August to December) fires. This gives scope for increasing the carbon stock in the dead wood pool with a reduced fire frequency. Following a previously published approach to quantify total dead wood loads in savannas, new and previously collected data on tree stand structures were used across the whole savanna zone to quantify dead wood loads in equilibrium with historic fire regimes. New parameters are presented for calculating dead wood dynamics including dead trees in Australia’s savannas.
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Tapper, NJ, G. Garden, J. Gill, and J. Fernon. "The Climatology and Meteorology of High Fire Danger in the Northern Territory." Rangeland Journal 15, no. 2 (1993): 339. http://dx.doi.org/10.1071/rj9930339.
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In most areas of Australia the calculation of a fire danger index (FDI) is the cornerstone of fie weather forecasting and provides an operationally objective basis for the issue of fire weather warnings. FDI's are derived from the observation or prediction of a number of basic meteorological parameters which are then combined with information on fuel characteristics. The forest and grassland fire danger in southern Australia is greatest during the austral summer and is characterised by long periods of low fire danger interspersed with occasional extreme fire danger events. By contrast, much of tropical and subtropical Australia shows a distinctly different seasonality, magnitude and frequency of fire danger. The problem is essentially one of the austral winter-spring (dry season) period and is characterised by extended periods of moderate to high fire danger. This paper provides a broad climatological background to the problem of high fire danger in northern Australia, concentrating in particular on the Northern Territory. The paper also addresses particular meteorological situations in northern Australia which give rise to elevated fire danger. Two synoptic-scale weather patterns are discussed in particular; the passage of prefrontal troughs which seasonally produce high fire danger in the region of the tropic, and winter subtropical ridging which produces strong winds and high fire danger over the north of the continent during the dry season.
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Burrows, G. E., S. K. Hornby, D. A. Waters, S. M. Bellairs, L. D. Prior, and D. M. J. S. Bowman. "A wide diversity of epicormic structures is present in Myrtaceae species in the northern Australian savanna biome - implications for adaptation to fire." Australian Journal of Botany 58, no. 6 (2010): 493. http://dx.doi.org/10.1071/bt10107.
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Recent research has shown that the eucalypts of southern Australia have an unusual and apparently fire-adapted epicormic structure. By studying a range of myrtaceous species from northern Australia we hoped to determine if this structure was also present in northern eucalypts. We anatomically examined the epicormic structures from 21 myrtaceous species in 11 genera from the north of the Northern Territory, Australia. An extremely wide diversity of epicormic structures was found, ranging from buds absent, buds at or near the bark surface, to bud-forming meristems in the innermost bark. These Myrtaceae species displayed a far greater variation in epicormic structure than recorded in any other family. This is possibly a reflection of the importance of the resprouter strategy, a long fire history in Australia and the ecological diversification of the Myrtaceae. Nonetheless, all the investigated eucalypts (northern and southern) possessed the same specialised, apparently fire-adapted, epicormic structure. This is remarkably consistent given the taxonomic, geographical and morphological diversity of the eucalypts.
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Greenville, Aaron C., Chris R. Dickman, Glenda M. Wardle, and Mike Letnic. "The fire history of an arid grassland: the influence of antecedent rainfall and ENSO." International Journal of Wildland Fire 18, no. 6 (2009): 631. http://dx.doi.org/10.1071/wf08093.
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Implementing appropriate fire regimes has become an increasingly important objective for biodiversity conservation programs. Here, we used Landsat imagery from 1972 to 2003 to describe the recent fire history and current wildfire regime of the north-eastern Simpson Desert, Australia, within each of the region’s seven main vegetation classes. We then explored the relationship between antecedent rainfall and El Niño–Southern Oscillation with wildfire area. Wildfires were recorded in 11 years between 1972 and 2003, each differing in size. In 1975, the largest wildfire was recorded, burning 55% (4561 km2) of the study region. Smaller fires in the intervening years burnt areas that had mostly escaped the 1975 fire, until 2002, when 31% (2544 km2) of the study region burnt again. Wildfires burnt disproportionally more spinifex (Triodia basedowii) than any other vegetation class. A total of 49% of the study area has burnt once since 1972 and 20% has burnt twice. Less than 1% has burnt three times and 36% has remained unaffected by wildfire since 1972. The mean minimum fire return interval was 26 years. Two years of cumulative rainfall before a fire event, rainfall during the year of a fire event, and the mean Southern Oscillation Index from June to November in the year before a fire event could together be used to successfully predict wildfire area. We use these findings to describe the current fire regime.
9
Budd, GM, JR Brotherhood, AL Hendrie, SE Jeffery, FA Beasley, BP Costin, W. Zhien, MM Baker, NP Cheney, and MP Dawson. "Project Aquarius 1. Stress, Strain, and Productivity in Men Suppressing Australian Summer Bushfires With Hand Tools: Background, Objectives, and Methods." International Journal of Wildland Fire 7, no. 2 (1997): 69. http://dx.doi.org/10.1071/wf9970069.
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This is the first in a series of 13 papers about the safety and productivity of firefighters suppressing wildland fires ('bushfires' in Australia) with hand tools, with particular emphasis on their physiological and subjective responses and the factors that influence them. The measurements were made during a broader investigation to determine the most intense fire that could be suppressed by hand tools, by bulldozers, and by air tankers. The investigation was carried out during three successive summers in dry eucalypt forests of Western Australia and Victoria. Four crews, each of 7 or 8 male firefighters, were studied while they attempted, for periods of 35-220 minutes, to suppress well-developed experimental bushfires with hand tools, and also while they built fireline in the same way without fire. Additional studies were made under controlled conditions: outdoors in the forest, indoors in field laboratories, and in a climatic chamber in Sydney. Most of the measurements were also made on the scientific observers, who shared the firefighters' environment but performed less strenuous work. All findings were highly consistent over the four crews, three summers, and two States and are thus generally applicable to bushfire suppression with hand tools in southern Australia.
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Parsons, R. F. "Carpobrotus modestus(Aizoaceae), a post-fire pioneer in semi-arid southern Australia." Journal of Arid Environments 37, no. 3 (November 1997): 453–59. http://dx.doi.org/10.1006/jare.1997.0288.
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Harris, S., N. Tapper, D. Packham, B. Orlove, and N. Nicholls. "The relationship between the monsoonal summer rain and dry-season fire activity of northern Australia." International Journal of Wildland Fire 17, no. 5 (2008): 674. http://dx.doi.org/10.1071/wf06160.
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Fire is an essential element of the northern Australian ecosystems with extensive areas burnt each year. The basic climate condition of high rainfall during the summer monsoon, followed by an extended warm dry winter, along with highly combustible vegetation (much of which grows rapidly during summer and senesces during winter), creates a highly flammable environment. These vegetation conditions change under various naturally occurring climate oscillations such as El Niño–Southern Oscillation (ENSO). The present paper investigates the link between burnt areas of northern Australia, rainfall, the Southern Oscillation Index (SOI) and sea surface temperatures (SST) for a 9-year period (1997–2005). The burnt area distribution is compared with the strength and timing of the monthly averaged rainfall, SOI and SST. Results indicate a strong relationship between antecedent rainfall and ENSO indices with area burnt. This is especially strong between the burnt areas of June–October and the preceding rainfall of November–March (r = 0.90), the SOI of November–February (r = 0.78) and the SST of June–August (r = –0.64). The results from the present study reveal the ability to forecast annual burnt areas and present some of the dynamics of the climate–fire interactions and their value for management systems.
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Craig, AB. "Fire Management of Rangelands in the Kimberley Low-Rainfall Zone: a Review." Rangeland Journal 21, no. 1 (1999): 39. http://dx.doi.org/10.1071/rj9990039.
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This paper examines a range of environmental, research and practical issues affecting fire management of pastoral lands in the southern part of the Kimberley region in Western Australia. Although spinifex grasslands dominate most leases, smaller areas of more productive pastures are crucially important to many enterprises. There is a lack of local documentation of burning practices during traditional Aboriginal occupation; general features of the fire regime at that time can be suggested on the basis of information from other inland areas. Definition of current tire regimes is improving through interpretation of NOAA-AVHRR satellite imagery. Irregular extensive wildfires appear to dominate, although this should be confirmed by further accumulation, validation and analysis of fire history data. While these fires cause ma,jor difficulties. controlled burn~ng is a necessary part of station management. Although general management guidelines have been published. local research into tire-grazing effects has been very limited. For spinifex pastures, reconimendations are generally consistent with those applying elsewhere in northern Australia. They favour periodic burning of mature spinifex late in the year, before or shortly after the arrival of the first rains, with deferment of grazing. At that time. days of high fire danger may still be expected and prediction of fire behaviour is critical to burning decisions. Early dry-season burning is also required for creating protective tire breaks and to prepare for burning later in the year. Further development of tools for predicting fire behaviour, suited to the discontinuous fuels characteristic of the area, would be warranted. A range of questions concerning the timing and spatial pattern of burning, control of post-fire grazing, and the economics of fire management, should be addressed as resources permit. This can be done through a combination of opportunistic studies, modelling and documentation of local experience. The development of an expert system should be considered to assist in planning and conducting burning activities. Key words: Kimberley, fire regimes, fire management, pastoralism, spinifex
13
Clarke, Michael F., Sarah C. Avitabile, Lauren Brown, Kate E. Callister, Angie Haslem, Greg J. Holland, Luke T. Kelly, et al. "Ageing mallee eucalypt vegetation after fire: insights for successional trajectories in semi-arid mallee ecosystems." Australian Journal of Botany 58, no. 5 (2010): 363. http://dx.doi.org/10.1071/bt10051.
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A critical requirement in the ecological management of fire is knowledge of the age-class distribution of the vegetation. Such knowledge is important because it underpins the distribution of ecological features important to plants and animals including retreat sites, food sources and foraging microhabitats. However, in many regions, knowledge of the age-class distribution of vegetation is severely constrained by the limited data available on fire history. Much fire-history mapping is restricted to post-1972 fires, following satellite imagery becoming widely available. To investigate fire history in the semi-arid Murray Mallee region in southern Australia, we developed regression models for six species of mallee eucalypt (Eucalyptus oleosa F.Muell. ex. Miq. subsp. oleosa, E. leptophylla F.Muell. ex. Miq., E. dumosa J. Oxley, E. costata subsp. murrayana L. A. S. Johnson & K. D. Hill, E. gracilis F.Muell. and E. socialis F.Muell. ex. Miq.) to quantify the relationship between mean stem diameter and stem age (indicated by fire-year) at sites of known time since fire. We then used these models to predict mean stem age, and thus infer fire-year, for sites where the time since fire was not known. Validation of the models with independent data revealed a highly significant correlation between the actual and predicted time since fire (r = 0.71, P < 0.001, n = 88), confirming the utility of this method for ageing stands of mallee eucalypt vegetation. Validation data suggest the models provide a conservative estimate of the age of a site (i.e. they may under-estimate the minimum age of sites >35 years since fire). Nevertheless, this approach enables examination of post-fire chronosequences in semi-arid mallee ecosystems to be extended from 35 years post-fire to over 100 years. The predicted ages identified for mallee stands imply a need for redefining what is meant by ‘old-growth’ mallee, and challenges current perceptions of an over-abundance of ‘long-unburnt’ mallee vegetation. Given the strong influence of fire on semi-arid mallee vegetation, this approach offers the potential for a better understanding of long-term successional dynamics and the status of biota in an ecosystem that encompasses more than 250 000 km2 of southern Australia.
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Lamont, BB, and A. Markey. "Biogeography of Fire-Killed and Resprouting Banksia Species in South-Western Australia." Australian Journal of Botany 43, no. 3 (1995): 283. http://dx.doi.org/10.1071/bt9950283.
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Banksia includes 38 fire-killed (seeders) and 20 resprouting species, and two species with contrasting ecotypes, in south-western Australia. There may be up to 12 seeders per 50 × 50 km grid cell in the southern sandplains and 12 resprouters in the northern sandplains. The patterns of distribution of species across soil type and eight climatic attributes is similar for both life forms, except that greater numbers of resprouting species occur at higher rainfalls and where there is greater seasonal spread of rainfall. Most seeders occur on white sands and rocky substrates, and resprouters occur on yellow sands and the more fertile lateritic soils. Nutrient requirements for both life forms appear to be similar. Resprouters are more widespread than seeders which suggests that resprouters show greater environmental tolerances. The distribution of grid cells containing each life form across soil types and eight climatic attributes is similar and any differences in climatic profile for all species in each category are considered biologically insignificant. Both life forms in section Abietinae are well represented in the climatically distinct southern and northern sandplains indicating no climatic preferences within the lineage. There are no consistent trends in environmental attributes from fire-killed to resprouting ecotypes of B. ashbyi E.G.Baker and B. violacea C.A. Gardner. Multiple-partitioning classification of the floristic data produced 10 groups varying greatly in geography, species richness, and proportion and endemism of each life form. The Lesueur (northern) district has four endemic seeders, six endemic resprouters and a mean of 10 resprouters per cell. The East Eyre (southern) district has five endemic seeders, no endemic resprouters and one resprouter per cell. Both groups have a mean growing season of 5 months. The relative aridities and fluctuations of present and past (Quaternary and late Tertiary) climates are invoked to explain the much higher proportion of resprouters in the northern than southern sandplains and the absence of seeders in the most marginal cells. The absence of endemic species yet high proportion of resprouters (73%) in the extreme south-western corner of the region might be explained by elimination of seeders through frequent burning by Aborigines in the late Quaternary. The increase in the proportion of fire-killed species along the south coast from 23% to 100% at the edge of the Nullarbor Plain also requires an explanation.
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Southgate, Richard, and Susan Carthew. "Post-fire ephemerals and spinifex-fuelled fires: a decision model for bilby habitat management in the Tanami Desert, Australia." International Journal of Wildland Fire 16, no. 6 (2007): 741. http://dx.doi.org/10.1071/wf06046.
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Seed from post-fire ephemeral plants like Yakirra australiense can form an important component of the diet of the bilby, a threatened arid-dwelling bandicoot. An investigation was conducted to determine the factors affecting the production of Yakirra and fire reoccurrence in the Tanami Desert. A simple decision model was produced to assist managers decide where and when to burn and what to expect regarding Yakirra australiense growth following fire and rainfall. The information used in the model may be derived from existing spatial databases that document rainfall and fire history and could be used to map broad-scale temporal change in total vegetation cover and components of habitat suitability for the bilby. The season and magnitude of rainfall and time-since-fire were the most important variables in the production of Yakirra seed. Rainfall >300 mm within a 2-month period of intense-complete burns could result in >5% Yakirra cover, and >100 mm was required for >1% cover. Negligible Yakirra cover occurred in adjacent long-unburnt plots. Total ground cover and spinifex cover varied substantially in relation to mean annual rainfall, but not in relation to substrate type. Long-unburnt spinifex cover was mostly too sparse to carry a fire in the southern part of the Tanami and the growth of non-spinifex vegetation would be necessary to boost fuel loads sufficiently to carry a fire. Generally, more than 41% cover was required to carry a fire but this was also dependent on weather conditions. Managers should aim to burn in late spring or early summer to improve Yakirra production. Fire management to enhance habitat suitability for the bilby would be of most benefit in the northern part of the Tanami Desert where growth rate of vegetation is greater and there is little existing fire age heterogeneity.
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Abensperg-Traun, Max, Dion Steven, and Lyn Atkins. "The influence of plant diversity on the resilience of harvester termites to fire." Pacific Conservation Biology 2, no. 3 (1995): 279. http://dx.doi.org/10.1071/pc960279.
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The harvester termites in floristically rich mallee-heath of southern Western Australia appear resilient to high-intensity fire. This contrasts with the temporary extinction of harvesters occupying a narrow food niche in floristically simple, intensely burnt spinifex Triodia angusta grassland in tropical Western Australia. The present study examines the effects of high-intensity fire on harvester termites Drepanotermes tamminensis in vegetation of intermediate floristic diversity and compares its findings with these earlier studies. We sampled 20 mounds (termitaria) in both an unburnt and (adjacent) burnt stand of Allocasuarina campestris shrubland. Although partially regenerated three years after the fire, 40% of mounds in the burnt area were abandoned, contrasting with 10% in the unburnt stand. No harvested chaff was found in any of the abandoned mounds. The extent of mound occupation by D. tamminensis was considerably lower, and ant invasion higher, in the burnt stand. These findings are consistent with the hypothesis that high floristic diversity enhances the resilience of harvester termites to fire. The most likely mechanism is the availability of a range of plant (food) species with different regenerative responses to high-intensity fire. The death of spinifex and the associated harvester termites after fire may be atypical. We argue, however, that temporary extinction of harvester populations in arid Australia may not be exceptional, particularly where fire coincides with drought and high livestock grazing pressure. Rigorous experimental studies are necessary to enhance our understanding of the long-term effects of fire on harvester termite populations in different vegetation types and climatic zones.
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Noble, JC. "Behaviour of a Very Fast Grassland Wildfire on the Riverine Plain of Southeastern Australia." International Journal of Wildland Fire 1, no. 3 (1991): 189. http://dx.doi.org/10.1071/wf9910189.
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A grassland wildfire burnt 120,000 ha in the western Riverina of New South Wales and caused exten sive losses of sheep and fencing. The rate of spread of the fire was accurately recorded at 6.4 m s-1 (23 km h-1) as it traversed one property and on the basis of conservative estimates of fuel loads measured later on unburnt patches, a fireline intensity was calculated at around 20,000 kW m-1. This rate of spread is one of the highest recorded for grassland wildfires in southern Australia and represents an important datum point for wildfire behaviour models. Quite reasonable predictions of rate of spread were pro vided by the McArthur Mark 4 fire danger model, how ever, the Mark 5 model seriously underestimated rate of spread for this and two other grassland wildfires.
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Williams, JE, RJ Whelan, and AM Gill. "Fire and Environmental Heterogeneity in Southern Temperate Forest Ecosystems: Implications for Management." Australian Journal of Botany 42, no. 2 (1994): 125. http://dx.doi.org/10.1071/bt9940125.
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Fire is a natural part of most Australian landscapes and has an important influence on the biological productivity and biotic composition of many ecosystems. Although fire is commonly used as a management tool, the precise nature of the way it may influence productivity and biotic composition is often poorly understood and, as a consequence, its use is controversial. This paper considers the use of fire for the management of ecosystems. Specifically, the influences of fire on environmental heterogeneity and the effects these have on shaping biological productivity and biotic patterns are discussed. Heterogeneity that affects biotic response includes variation in biophysical attributes of landscapes such as topography, fire regimes and the spatial attributes of fire. Examples are used to address the interplay between fires, environmental heterogeneity and biological patterns: (1) the effects of frees on plant resource availability; (2) crown scorch in eucalypt forests; and (3) the effects of spatial variation (patchiness) within a fire on species composition. Heterogeneity should be considered explicitly in management because prescriptions devised elsewhere may not be able to be imported with confidence to all sites and the responses of the biota to fires may differ from available information. Ecological monitoring and research into the ecological effects of heterogeneity are required to provide a predictive understanding of natural systems and provide information to aid decisions about the use of fire as a management tool.
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Brandle, R., and K. E. Moseby. "Comparative ecology of two populations of Pseudomys australis in northern South Australia." Wildlife Research 26, no. 4 (1999): 541. http://dx.doi.org/10.1071/wr97049.
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Two disparate populations of Pseudomys australis, in the southern and north-western Lake Eyre Basin of South Australia, were studied over a 3-year period using trapping and radio-tracking techniques. Various aspects of the species’ ecology were investigated. Past records of the species were almost always associated with population irruptions following exceptionally wet years. Aspects of population dynamics, fine-scale habitat use, activity ranges and burrows were studied and related to habitat condition during three dry seasons following a good season. Both areas were associated with floodout plains in a gibber desert environment but differed in soils and vegetation structure. The population dynamics and structure and home-range activity also differed. These differences appeared to relate to the availability and distribution of food and shelter in the respective locations. The differences between populations in the two areas are discussed with reference to the source/sink and refugia concepts.
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W. Norton, Tony, and Neil D. Mitchell. "Towards the sustainable management of southern temperate forest ecosystems: lessons from Australia and New Zealand." Pacific Conservation Biology 1, no. 4 (1994): 293. http://dx.doi.org/10.1071/pc940293.
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The temperate forest ecosystems of Australia and New Zealand have had a similar history of exploitation and destruction since European settlement. This differed markedly from the previous use of these forests by indigenous peoples. Australian Aborigines are considered to have used the forests on a sustainable basis. Fire was the primary management tool and probably had its greatest effect on floristic composition and structure. The Maori of New Zealand initially cleared substantial areas of forest, but by the time of European settlement they appear to have been approaching sustainable management of the remainder. In both countries, the arrival of Europeans disrupted sustainability and significantly changed the evolutionary history of the forests and their biota. The exploitation and destruction of temperate forests by Europeans in both countries has been driven largely by agricultural and forestry activities, based around settlement and export industries. The Australian continent never had substantial forest cover but this has been reduced by more than half in just 200 years. New Zealand has suffered a similar overall level of further loss; although in the lowlands this can reach 95 per cent. In recent times, forest production and management policies in the two countries have diverged. In both countries the majority of remaining indigenous forests are on publicly-owned land. Australia still maintains indigenous forest production as an industry exploiting old growth forests, the management being split between an emphasis on production forestry and nature conservation. New Zealand has largely abandoned indigenous forestry on public lands, the management being vested in a single conservation department. In New Zealand the production emphasis has mostly moved to sustainable plantation forestry, whereas in Australia, despite recommendations to halt or markedly reduce old growth forest logging, the transition to primary dependence on plantation production has yet to occur.
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Wilson, Barbara A., Janine Kuehs, Leonie E. Valentine, Tracy Sonneman, and Kristen M. Wolfe. "Guidelines for ecological burning regimes in Mediterranean ecosystems: a case study in Banksia woodlands in Western Australia." Pacific Conservation Biology 20, no. 1 (2014): 57. http://dx.doi.org/10.1071/pc140057.
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In Mediterranean ecosystems prescribed burning is commonly employed to reduce the risk or intensity of wildfires. As a consequence, a major challenge for conservation land managers is the development of fire regimes that reduce damaging wildfires and are optimal for biodiversity. The aim of this paper was to develop guidelines for ecological fire regimes using the Banksia woodland on the Gnangara Groundwater System in Western Australia as a case study. Development of the guidelines involved the determination of maximum and minimum fire intervals of key fire response species, analyses of fire history records and estimation of ideal age class distributions at the landscape level. Recommendations included a) adoption of a minimum fire interval of 8–16 years, b) implementation of a burning regime to redress the current skewed distribution (60%: 1–7 years since last fire), c) retention of long-unburnt habitats that are significant for species such as the critically endangered Calyptorhynchus latirostris (Carnaby’s black-cockatoo), and Tarsipes rostratus (honey possum), and d) protection for wetlands that can serve as fire ‘refugia’ for associated species, such as Isoodon obesulus fusciventer (southern brown bandicoot or quenda). The guidelines developed provide a model for the development of ecological burning regimes in other similar ecosystems. The implementation of ecological guidelines normally involves incorporation into fire management planning by fire agencies and often entails complex solutions to conflicting aims. The guidelines are thus valuable for ecologists and land managers, especially in light of an expected significant increase in global fire activity as a consequence of predicted climate change.
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Liu, Xiaoni, Baisen Zhang, Beverley Henry, Jinglan Zhang, and Peter Grace. "Assessing the impact of historical and future climate change on potential natural vegetation types and net primary productivity in Australian grazing lands." Rangeland Journal 39, no. 4 (2017): 387. http://dx.doi.org/10.1071/rj17081.
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The study investigated the impact of historical and future climate changes on potential natural vegetation (PNV) types and net primary productivity (NPP) in Australia, using the Comprehensive and Sequential Classification System model and the Miami model coupled with climate of the 1931–70 and 1971–2010 periods and the projected climate in 2050. Twenty-eight vegetation classes were classified based on the key climate indicators with four of them being the major vegetation classes corresponding to Australian rangelands and accounting for 75% of total land area. There was a substantial shift in areas of vegetation classes from the 1931–70 period to the 1971–2010 period due to the increased rainfall over large areas across Australia. The modelling projected a range of changes in vegetation classes for 2050 depending on the climate-change scenario used. Many vegetation classes with more intense land use (e.g. steppe and forest) were projected to decrease in 2050, which may have significant impact on the grazing industry and biodiversity conservation. By 2050, NPP was projected to increase in central and northern Australia and to decrease in southern and eastern coastal areas and was projected to be higher on average than that of the 1931–70 period. The vegetation classes approximately corresponding to Australian rangelands mostly had increased NPP projections compared with the 1931–70 period. Although actual response will partially depend on human management activities, fire and extreme events, the projected increase in average NPP in 2050 indicates that Australian vegetation, particularly the rangeland vegetation, will likely be a net carbon sink rather than a carbon source by 2050, with the exception of a ‘warm-dry’ scenario.
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Jones, Penelope J., Ian Thomas, and Michael-Shawn Fletcher. "Long-term environmental change in eastern Tasmania: Vegetation, climate and fire at Stoney Lagoon." Holocene 27, no. 9 (February 16, 2017): 1340–49. http://dx.doi.org/10.1177/0959683617690591.
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Tasmania’s dry, inland east is ideally positioned to inform models of late Quaternary environmental change in southern Australasia. Despite this, it remains poorly represented in the palaeoecological record. Here, we seek to address this with a >13,000-year vegetation and fire history from Stoney Lagoon, a site at the eastern margin of Tasmania’s inland Midlands plains. Pollen and charcoal analysis indicates that here, a relatively moist early deglacial was followed by a dry later deglacial (ca. 14,000–12,000 cal. BP), when sclerophyll forests became well established and burning increased. This suggests that the Midlands’ vegetation responded to the climatic signals characterising Australia’s south-eastern coast rather than those governing developments in western Tasmania. Dry sclerophyll forest persisted throughout the Holocene; with a pronounced transition from more to less grassy understoreys between ca. 9000 and 7000 cal. BP. From the mid-Holocene, the sclerophyll community remains relatively stable. However, increased fire activity and trends in moisture-sensitive taxa suggest generally drier conditions coupled with greater hydroclimatic variability under the strengthening influence of the El Niño–Southern Oscillation (ENSO). Overall, these results highlight the role of macro-scale climatic shifts in shaping vegetation development in Tasmania’s inland east, while hinting at the concurrent importance of local ecological drivers. This highlights the need for spatially diverse studies to understand interactions between drivers of long-term environmental change in sub-humid southern Australia. This research also supports conservation by strengthening understandings of pre-colonial baselines in this highly modified landscape.
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Brotherhood, JR, GM Budd, AL Hendrie, SE Jeffery, FA Beasley, BP Costin, W. Zhien, MM Baker, NP Cheney, and MP Dawson. "Project Aquarius 3. Effects of Work Rate on the Productivity, Energy Expenditure, and Physiological Responses of Men Building Fireline With a Rakehoe in Dry Eucalypt Forest." International Journal of Wildland Fire 7, no. 2 (1997): 87. http://dx.doi.org/10.1071/wf9970087.
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Four crews of firefighters built fireline for 7 min periods (with intervening rests), without fire, at self-chosen 'slow', 'normal', and 'fast' rates in Australian eucalypt forests. Individuals differed twofold for energy expenditure (EE, measured as oxygen uptake by the Douglas bag technique) and relative work load (RWL, i.e % of maximum oxygen uptake), and threefold for productivity and efficiency (productivity per unit EE). They maintained their differences in all stages of the test and also while suppressing free-running wildland fires, showing that the work rate adopted was a stable characteristic of the individuals' work behaviour. The technique of raking fireline did not constrain EE but instead allowed firefighters to call upon their maximum work capacity for urgent tasks with no reduction in efficiency. EE, RWL, and heart rate increased linearly with productivity whereas perceived exertion and pulmonary ventilation increased curvilinearly, rising steeply at 'fast' work rates. We suggest that perceived exertion and the ventilatory threshold (the upper limit of comfortable breathing) provide the cues by which firefighters pace themselves at sustainable work rates that balance their fireline productivity against its physiological cost. The findings were highly consistent over four crews, three summers, and two regions and are thus generally applicable to bushfire suppression in southern Australia.
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Hopper, Stephen D., and Nathan K. McQuoid. "Two new rare species and a new hybrid in Eucalyptus series Tetrapterae (Myrtaceae) from southern coastal Western Australia." Australian Systematic Botany 22, no. 3 (2009): 180. http://dx.doi.org/10.1071/sb06034.
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Three new rare taxa allied to the conspicuous, common four-winged mallee (Eucalyptus tetraptera Turcz.) are described. E. sweedmaniana is a large-leaved and prostrate coastal mallee known only from Mount Arid, Western Australia. E. brandiana, a non-lignotuberous mallet, occupies spongolite hilltops and escarpments near the Fitzgerald River Inlet in Fitzgerald River National Park, Western Australia. A single hybrid mallet, E. arborella × brandiana, is described from the type locality of E. brandiana. Both new species and the new hybrid show potential for horticultural use, given their compact habit, large leaves and conspicuous red floral hypanthia and fruits. E. arborella × brandiana and E. brandiana are particularly at risk, being highly localised endemics that are killed by fire.
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Sluiter, Ian R. K., David T. Blackburn, and Guy R. Holdgate. "Fire and Late Oligocene to Mid-Miocene peat mega-swamps of south-eastern Australia: a floristic and palaeoclimatic interpretation." Australian Journal of Botany 64, no. 8 (2016): 609. http://dx.doi.org/10.1071/bt16165.
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The Late Oligocene to Mid-Miocene (25–13 million years ago) brown coals of the Gippsland Basin in southern Victoria, Australia, were deposited in peat mega-swamps, unlike any in the world at the present day. The swamps preserve a rich botanical suite of macro- and microfossils, many of which can be identified with plant genera and families present today in Australia, New Caledonia, New Zealand and New Guinea. The peat-forming environments also preserve evidence of past burning in the form of micro-charcoal as well as macro-charcoal, the latter being evident as regional lenses or layers of fusinite, generally in coals of the darkest colour termed dark lithotypes. The presence of micro-charcoal in dark and some other lighter lithotypes indicated that fires also burnt locally, although they may have been extinguished before regional-scale burning occurred. It is also feasible that some peat mega-swamp plant communities dominated by rainforest angiosperm plants may have been fire excluders and prevented widespread fires from developing. Pollen and macrofossil evidence is presented of a distinctive southern conifer and angiosperm flora with an open canopy, primarily associated with the darkest coals that formed in the wettest parts of the peat-forming environment. Elsewhere, swamp forests with a large rainforest component grew on swamps raised appreciably above the regional groundwater table in a structural context akin to the ombrogenous peats of tropical coastal Sumatra and Sarawak. These vegetation types were not fire prone, but may have occasionally burnt at a local scale or at forest margins. Evidence is presented for the existence of seasonal climatic conditions that would appear to have facilitated a drying-out of the peat swamps in the warmest months of the year. A mesothermal climate was invoked where mean annual precipitation was at least 1500 mm, and possibly as much as 2000 mm, and mean annual temperatures were ~19°C.
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Teckentrup, Lina, Martin G. De Kauwe, Andrew J. Pitman, Daniel S. Goll, Vanessa Haverd, Atul K. Jain, Emilie Joetzjer, et al. "Assessing the representation of the Australian carbon cycle in global vegetation models." Biogeosciences 18, no. 20 (October 20, 2021): 5639–68. http://dx.doi.org/10.5194/bg-18-5639-2021.
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Abstract. Australia plays an important role in the global terrestrial carbon cycle on inter-annual timescales. While the Australian continent is included in global assessments of the carbon cycle such as the global carbon budget, the performance of dynamic global vegetation models (DGVMs) over Australia has rarely been evaluated. We assessed simulations of net biome production (NBP) and the carbon stored in vegetation between 1901 to 2018 from 13 DGVMs (TRENDY v8 ensemble). We focused our analysis on Australia's short-term (inter-annual) and long-term (decadal to centennial) terrestrial carbon dynamics. The TRENDY models simulated differing magnitudes of NBP on inter-annual timescales, and these differences resulted in significant differences in long-term vegetation carbon accumulation (−4.7 to 9.5 Pg C). We compared the TRENDY ensemble to several satellite-derived datasets and showed that the spread in the models' simulated carbon storage resulted from varying changes in carbon residence time rather than differences in net carbon uptake. Differences in simulated long-term accumulated NBP between models were mostly due to model responses to land-use change. The DGVMs also simulated different sensitivities to atmospheric carbon dioxide (CO2) concentration, although notably, the models with nutrient cycles did not simulate the smallest NBP response to CO2. Our results suggest that a change in the climate forcing did not have a large impact on the carbon cycle on long timescales. However, the inter-annual variability in precipitation drives the year-to-year variability in NBP. We analysed the impact of key modes of climate variability, including the El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), on NBP. While the DGVMs agreed on sign of the response of NBP to El Niño and La Niña and to positive and negative IOD events, the magnitude of inter-annual variability in NBP differed strongly between models. In addition, we find that differences in the timing of simulated phenology and fire dynamics are associated with differences in simulated or prescribed vegetation cover and process representation. We further find model disagreement in simulated vegetation carbon, phenology, and apparent carbon residence time, indicating that the models have different types and coverage of vegetation across Australia (whether prescribed or emergent). Our study highlights the need to evaluate parameter assumptions and the key processes that drive vegetation dynamics, such as phenology, mortality, and fire, in an Australian context to reduce uncertainty across models.
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Hu, Yang, Graeme Gillespie, and Tim S. Jessop. "Variable reptile responses to introduced predator control in southern Australia." Wildlife Research 46, no. 1 (2019): 64. http://dx.doi.org/10.1071/wr18047.
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Context Australia harbours an immense diversity of reptiles, which are generally expected to have frequent and diverse trophic interactions with introduced mammalian carnivores. Nevertheless, the potential for predatory or competitive interactions is likely to be contingent on multiple processes, including the importance of reptiles in the diet of introduced predators, alongside overlaps in their body sizes and ecological niches that would influence the strength of their interactions. In Australia’s temperate and relatively productive mesic environments there is little understanding of how introduced mammalian predators affect reptile assemblages. Aims The aim was to investigate the effects that a European red fox (Vulpes vulpes; 5–7kg) suppression program had on the abundance and species richness of a reptile community, with species ranging in size from the largest local ectothermic predator, the lace monitor (Varanus varius; 4–7kg), to small terrestrial reptiles (mostly 10–150g). Methods We utilised two sampling designs (baited camera monitoring stations and pitfall trapping) to evaluate the effects of fox suppression and other site-level ecological covariates (fire regime and habitat vegetation characteristics) on the lace monitor and small terrestrial reptiles. Reptile abundance and richness at site level were estimated from count-related abundance models. Key results For lace monitors, significantly higher abundances occurred in poison-baited areas relative to control areas. This suggests that fox suppression can affect the populations of the lace monitor via mesopredator release arising from reduced competition and, possibly, predation. For small terrestrial reptiles, neither abundance nor species richness were influenced by fox suppression. Individual abundances of the three most common small reptile species matched the overall pattern, as only responses to structural parameters of the habitat were detected. Conclusions Fox suppression can have different impacts for different reptile taxa, pending their ecological niche, as only the largest species was affected. Implications Increase in lace monitor abundance may change food web dynamics in fox-suppressed sites, such as by increasing predation pressure on arboreal marsupials.
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Groom, PK, and BB Lamont. "Ecogeographical Analysis of Hakea (Proteaceae) in South-Western Australia, With Special Reference to Leaf Morphology and Life Form." Australian Journal of Botany 44, no. 5 (1996): 527. http://dx.doi.org/10.1071/bt9960527.
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The genus Hakea Schrader (Proteaceae) has its world centre of diversity in south-western Australia; the majority (c. 70%) of species are endemic to this region. To examine the distribution of Hakea within south-western Australia, canonical correspondence analysis (CCA) was used on species presence and bioclimatic parameters in 0.5° x0.5° latitude-longitude grid cells. Of the 12 bioclimatic attributes initially applied, annual temperature and rainfall data, and indices of their variation, were best related to species distribution. Clustering of the species (on the CCA ordination) produced five distinct groups (not including species near the origin of the ordination) roughly representing floristic regions of southwestern Australia (Avon, Irwin, Eyre-Roe, southern Darling, northern-central Darling). Species distribution was then related to four morphological groups based on their leaf type (broad, terete) and post-fire life form (non-sprouter, resprouter). The highest percentage of terete-leaved non-sprouters occurred in areas of low-moderate rainfall and large annual temperature ranges (Avon and Eyre-Roe clusters), whereas terete-leaved resprouters displayed a very patchy distribution, accounting for less than 20% of the hakeas present in most of the grid cells. Broad-leaved resprouters dominated areas of strongly seasonal rainfall (Irwin and northern-central Darling clusters), with few species occurring in the drier Avon and Eyre-Roe districts. Broad-leaved non-sprouters were best represented in areas of low annual temperature (southern Darling and Eyre-Roe clusters). The distribution of non-sprouters and resprouters may be due to climatic factors affecting seedling recruitment and/or fire frequencies. Leaf morphology appears to be more directly related to species distribution, as broad leaves are favoured in regions of medium-high, seasonal rainfall (less stressful habitats) while terete leaves are better adapted to tolerate hot, dry environments.
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Reid, J., and M. Fleming. "The conservation status of birds in arid Australia." Rangeland Journal 14, no. 2 (1992): 65. http://dx.doi.org/10.1071/rj9920065.
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The impression has been given in previous studies that there are few bird conservation problems in the arid zone, particularly because not one of a total of 230 species has become extinct. In stark contrast, almost half of the native terrestrial mammalian fauna of the Australian arid zone has become extinct on the mainland since European occupation. Here we show that the status of one half of the avifauna has changed since European occupation, and conclude there are many threats to avian biodiversity at the regional scale in the arid zone. There are 19 species (8%) in the arid zone classified as rare and threatened nationally. Twelve more (5%) are uncommon species which have declined or are at risk in two or more regions. A further 40 species (17%) have declined in at least one arid region, although many of these remain common and some have increased elsewhere in arid Australia. At least 45 species (20%) have increased in range or abundance, including a suite of ground-feeding birds associated with degraded landscapes. Striking patterns emerged from analysis of 29 threatened and declining species: • birds associated with chenopod shrublands and grassy, riparian or floodplain environments have been most affected whereas mulga inhabitants and canopy-dwellers of riparian woodland have been little affected; • birds generally with a northem distribution have declined in the south of the arid zone and birds with a southern distribution have declined in the north of the arid zone, and these patterns contrast with many birds with a southern or continental distribution which have declined more in southern semiarid regions than within the arid zone itself; • birds which feed at ground and low shrub height have been most adversely affected; • sedentary bushbirds (passerines) are more at risk than nomads and their limited mobility seems to be a risk factor; • among non-passerines, parrots, cockatoos and pigeons are most at risk, while three passerine families stand out, namely wrens, quail-thrushes, and thornbills and allies; • contrary to findings for mammals, size does not generally appear to be an important risk factor. Land degradation and habitat alteration such as shifts in abundance or dominance of plant species caused by the introduction of exotic herbivores appear to be the principal factors causing change in status while the provision of reliable water sources in pastoral districts is also important. Introduced predators are implicated in some cases and altered fire regimes may have played a part in spinifex and mallee habitats. Competitive interactions between increasing and declining species, although not demonstrated, appear to be likely for some species. We have documented a hitherto unsuspected degree of change in avian biodiversity in the Australian arid zone. In the absence of widespread regeneration of dominant plant species in the southern arid zone, the decline of many arid zone birds will accelerate dramatically. Also, unless better management ensues, the next major drought could cause accelerated declines and extinctions. We advocate a range of measures designed to improve the conservation prospects for arid Australian birds, including lower stocking rates on pastoral properties, rehabilitation of critical habitats and their protection from exotic herbivores, experimental research on the impact of grazing and predation, and monitoring of both threatened species and a range of sedentary passerines typically associated with representative habitats in the arid zone.
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Lamont, Byron B., Neal J. Enright, E. T. F. Witkowski, and J. Groeneveld. "Conservation biology of banksias: insights from natural history to simulation modelling." Australian Journal of Botany 55, no. 3 (2007): 280. http://dx.doi.org/10.1071/bt06024.
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We have studied the ecology and conservation requirements of Banksia species in the species-rich sandplains of south-western Australia for 25 years. Loss of habitat through land-clearing has had the greatest impact on their conservation status over the last 50 years. Ascertaining optimal conditions for conservation management in bushland requires detailed knowledge of the species under consideration, including demographic attributes, fire regime, growing conditions and interactions with other species. Where populations have been fragmented, seed production per plant has also fallen. The group most vulnerable to the vagaries of fire, disease, pests, weeds and climate change are the non-sprouters, rather than the resprouters, with population extinction so far confined to non-sprouting species. Recent short-interval fires (<8 years) appear to have had little impact at the landscape scale, possibly because they are rare and patchy. Fire intervals exceeding 25–50 years can also lead to local extinction. Up to 200 viable seeds are required for parent replacement in Banksia hookeriana when growing conditions are poor (low post-fire rainfall, commercial flower harvesting) and seed banks of this size can take up to 12 years to be reached. Seed production is rarely limited by pollinators, but interannual seasonal effects and resource availability are important. Genetic diversity of the seed store is quickly restored to the level of the parents in B. hookeriana. Florivores and granivores generally reduce seed stores, although this varies markedly among species. In Banksia tricuspis, black cockatoos actually increase seed set by selectively destroying borers. Potential loss of populations through the root pathogen Phytophthora cinnamomi also challenges management, especially in the southern sandplains. Prefire dead plants are a poor source of seeds for the next generation when fire does occur. Harvesting seeds and sowing post-fire have much to commend them for critically endangered species. Bare areas caused by humans can result in ideal conditions for plant growth and seed set. However, in the case of B. hookeriana/B. prionotes, disturbance by humans has fostered hybridisation, threatening the genetic integrity of both species, whereas fine-textured soils are unsuitable for colonisation or rehabilitation. Few viable seeds become seedlings after fire, owing to post-release granivory and herbivory and unsuitable germination conditions. Seedling-competitive effects ensure that season/intensity of fire is not critical to recruitment levels, except in the presence of weeds. Water availability during summer–autumn is critical and poses a problem for conservation management if the trend for declining rainfall in the region continues. Our simulation modelling for three banksias shows that the probability of co-occurrence is maximal when fire is stochastic around a mean of 13 years, and where fire-proneness and post-fire recruitment success vary in the landscape. Modelling results suggest that non-sprouting banksias could not survive the pre-European frequent-fire scenario suggested by the new grasstree technique for south-western Australia. However, we have yet to fully explore the conservation significance of long-distance dispersal of seeds, recently shown to exceed 2.5 km in B. hookeriana.
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Vincent, Brian J., Sarah Barrett, Anne Cochrane, Julie A. Plummer, and Michael Renton. "Conservation biology of two endemic Beyeria species (Euphorbiaceae) from southern Western Australia." Australian Journal of Botany 63, no. 6 (2015): 484. http://dx.doi.org/10.1071/bt14310.
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Beyeria cockertonii Halford & R.J.F.Hend. and Beyeria villosa Halford & R.J.F.Hend. (Euphorbiaceae) are two short-range endemic monoecious congeners from southern Western Australia. We sought to determine whether life-history characteristics were responsible for their limited distribution and to identify aspects of their ecology that might render them vulnerable to current threatening processes. We investigated reproductive phenology in relation to climate, pollinator activity and synchronicity of male and female flowering. In addition seed dispersal, regeneration, demography and seed viability were examined and ex situ germination experiments conducted to determine seed-dormancy mechanisms. Flowering in the conservation-listed B. cockertonii was significantly correlated with temperature, whereas fruit set was correlated with pollinator abundance and movement; male and female flowering showed limited synchrony. The presence of soil-stored seeds lacking a caruncle at sites absent of adult plants of either species suggests that seed may be ant-dispersed (myrmecochory). Fresh seeds of B. cockertonii were significantly more viable than those of its more common congener, B. villosa (72 vs 0.5%, P < 0.001). Fresh B. cockertonii seeds would not germinate with an intact caruncle; caruncle removal elicited germination of 64% and 60% (10°C and 15°C, respectively). Aqueous smoke further stimulated germination to 72% and 83% germination (10°C and 15°C, respectively), providing a link between fire and germination. Beyeria villosa was affected by high levels of pre-dispersal predation (up to 70%) and seed abortion (88%) and appeared to have lower reproductive fitness than B. cockertonii. Life-history strategies did not explain the greater abundance and wider distribution of B. villosa than those of the conservation-listed B cockertonii, nor was the greater rarity of B. cockertonii fully explained by habitat specificity, with both species being restricted to ultra-mafic volcanic rock associated with Achaean greenstone. However, an apparent dependence of B. cockertonii on a specific insect pollinator from the family Miridae may render this species vulnerable to threatening processes.
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Brownlie, Heather, Julia Playford, Helen Wallace, and Alison Shapcott. "Population ecology and genetics of the vulnerable Acacia attenuata (Mimosaceae) and their significance for its conservation, recovery and translocation." Australian Journal of Botany 57, no. 8 (2009): 675. http://dx.doi.org/10.1071/bt09116.
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Acacia attenuata Maiden and Blakely, is a vulnerable shrub, endemic to south-east Queensland, Australia. The population ecology and genetics of the species were examined throughout its range to assist with conservation and recovery of the species. South-east Queensland is experiencing massive population expansion and the associated housing and infrastructure development is having an impact on the remnant vegetation in the region. Population sizes differed significantly (P < 0.05) and were smaller in the southern urbanised parts of the species distribution. Genetic diversity of A. attenuata was high in comparison to other Acacia species. Genetic diversity was not significantly correlated with population size or isolation. There was a high degree of genetic similarity among populations (FST = 0.101). Populations were effectively inbred (F = 0.482); however, inbreeding was not correlated with population size, density, isolation or reproductive activity. Uniform high levels of genetic diversity and low population differentiation suggest that A. attenuata once had a more continuous distribution. A population that was due to be translocated because of a development decision was also assessed as part of the research. The population at the development site (AA14 – Bundilla) was the largest and one of the most genetically variable sites, thus the genetic diversity of the population needs to be conserved within the translocation. The translocation process is reported here and occurred based on the information on genetics and ecology provided by this study. Population density and the proportion of seedlings and juveniles were significantly negatively correlated with time since fire. Fire regimes of 5–10 years are optimal for A. attenuata population regeneration and persistence, thus active fire management will be required for both the translocated population and for other populations within the urban and peri-urban areas, where competing demands make fire management controversial and difficult.
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Schwalm, C. R., C. A. Williams, K. Schaefer, I. Baker, G. J. Collatz, and C. Rödenbeck. "Does terrestrial drought explain global CO<sub>2</sub> flux anomalies induced by El Niño?" Biogeosciences Discussions 8, no. 3 (May 2, 2011): 4209–38. http://dx.doi.org/10.5194/bgd-8-4209-2011.
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Abstract. The El Niño Southern Oscillation is the dominant year-to-year mode of global climate variability. El Niño effects on terrestrial carbon cycling are mediated by associated climate anomalies, primarily drought, influencing fire emissions and biotic net ecosystem exchange (NEE). Here we evaluate whether El Niño produces a consistent response from the global carbon cycle. We apply a novel bottom-up approach to estimating global NEE anomalies based on FLUXNET data using land cover maps and weather reanalysis. We analyze 13 yr (1997–2009) of globally gridded observational NEE anomalies derived from eddy covariance flux data, remotely-sensed fire emissions at the monthly time step, and NEE estimated from an atmospheric transport inversion. We evaluate the overall consistency of biospheric response to El Niño and, more generally, the link between global CO2 flux anomalies and El Niño-induced drought. Our findings, which are robust relative to uncertainty in both methods and time-lags in response, indicate that each event has a different spatial signature with only limited spatial coherence in Amazônia, Australia and southern Africa. For most regions, the sign of response changed across El Niño events. Biotic NEE anomalies, across 5 El Niño events, ranged from −1.34 to +0.98 Pg C yr−1, whereas fire emissions anomalies were generally smaller in magnitude (ranging from −0.49 to +0.53 Pg C yr−1). Overall drought does not appear to impose consistent terrestrial CO2 flux anomalies during El Niños, finding large variation in globally integrated responses from −1.15 to +0.49 Pg C yr−1. Contrary to previous accounts we find El Niño events have, when globally integrated, both enhanced and weakened terrestrial sink strength, with no consistent response across events.
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Schwalm, C. R., C. A. Williams, K. Schaefer, I. Baker, G. J. Collatz, and C. Rödenbeck. "Does terrestrial drought explain global CO<sub>2</sub> flux anomalies induced by El Niño?" Biogeosciences 8, no. 9 (September 9, 2011): 2493–506. http://dx.doi.org/10.5194/bg-8-2493-2011.
Full textAbstract:
Abstract. The El Niño Southern Oscillation is the dominant year-to-year mode of global climate variability. El Niño effects on terrestrial carbon cycling are mediated by associated climate anomalies, primarily drought, influencing fire emissions and biotic net ecosystem exchange (NEE). Here we evaluate whether El Niño produces a consistent response from the global carbon cycle. We apply a novel bottom-up approach to estimating global NEE anomalies based on FLUXNET data using land cover maps and weather reanalysis. We analyze 13 years (1997–2009) of globally gridded observational NEE anomalies derived from eddy covariance flux data, remotely-sensed fire emissions at the monthly time step, and NEE estimated from an atmospheric transport inversion. We evaluate the overall consistency of biospheric response to El Niño and, more generally, the link between global CO2 flux anomalies and El Niño-induced drought. Our findings, which are robust relative to uncertainty in both methods and time-lags in response, indicate that each event has a different spatial signature with only limited spatial coherence in Amazônia, Australia and southern Africa. For most regions, the sign of response changed across El Niño events. Biotic NEE anomalies, across 5 El Niño events, ranged from –1.34 to +0.98 Pg C yr−1, whereas fire emissions anomalies were generally smaller in magnitude (ranging from –0.49 to +0.53 Pg C yr−1). Overall drought does not appear to impose consistent terrestrial CO2 flux anomalies during El Niños, finding large variation in globally integrated responses from –1.15 to +0.49 Pg C yr−1. Despite the significant correlation between the CO2 flux and El Niño indices, we find that El Niño events have, when globally integrated, both enhanced and weakened terrestrial sink strength, with no consistent response across events.
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Paveglio, Travis B., Matthew S. Carroll, and Pamela J. Jakes. "Adoption and perceptions of shelter-in-place in California's Rancho Santa Fe Fire Protection District." International Journal of Wildland Fire 19, no. 6 (2010): 677. http://dx.doi.org/10.1071/wf09034.
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The increasing impact of wildland fire on human settlements in the USA, and a growing recognition that evacuation might not always to the safest option for those in the path of the flames, continue to spur consideration of alternatives to evacuation among the American public and its fire professionals. Alternatives to evacuation typically include the option for residents to remain in fire-hardened structures while the flames pass; however, it appears there is no clear consensus on whether existing Australian alternatives or new variations should be used in American communities, and if any option will reduce risks to residents and firefighters. This study uses structuration theory to analyse adoption of the shelter-in-place policy created by the Rancho Santa Fe Fire Protection District in southern California. We interviewed professionals working in and around the District and the public affected by the policy. Results suggest that professional support and implementation of shelter-in-place are influenced by the breadth of their personal firefighting experience, their agencies’ flexibility and constraints on innovation, and perceived potential liability for damage from adoption of alternatives. Resident knowledge and understanding of shelter-in-place are also lacking. We conclude with recommendations for continued development of alternatives to evacuation.
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Rees, Michael, and David Paull. "Distribution of the southern brown bandicoot (Isoodon obesulus) in the Portland region of south-western Victoria." Wildlife Research 27, no. 5 (2000): 539. http://dx.doi.org/10.1071/wr99045.
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The southern brown bandicoot (Isoodon obesulus) occurs across the periphery of southern and eastern Australia as a series of isolated regional populations. Historical records and recent surveys conducted for I. obesulus indicate that it has disappeared or decreased significantly from many parts of its former range. Vegetation clearance, habitat fragmentation, feral predators and fire have all been implicated in the decline of the species. This paper examines the distribution of I. obesulus in the Portland region of south-western Victoria. Historical records of I. obesulus were compiled from the specimen collection of Museum Victoria, the Atlas of Victorian Wildlife, Portland Field Naturalists’ Club records and anecdotal sources. Field surveys were conducted to determine the current distribution of I. obesulus in the study area based on evidence of its foraging activity. The historical records reveal limited information: most are clustered around centres of human activity, indicating observational bias. The field surveys demonstrate that I. obesulus occurs in the Portland region as a series of local populations. Each local population is associated with a patch of remnant native vegetation separated from neighbouring patches by dispersal barriers. Within these habitat remnants the occurrence of the species is sporadic. Approximately 69% of the potential habitat is managed by the Forests Service, 31% is managed by Parks Victoria, and less than 0.5% is held under other tenures. Spatial isolation of habitat remnants, fires and feral predators are the main threats to I. obesulus in the Portland region.
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McFarland, DC. "Fire and the Vegetation Composition and Structure of Sub-Tropical Heathlands in Southeastern Queensland." Australian Journal of Botany 36, no. 5 (1988): 533. http://dx.doi.org/10.1071/bt9880533.
Full textAbstract:
Six heathland sites were studied in Cooloola National Park, south-eastern Queensland. Vegetation composition (species present and numbers) and structure (plant density, cover, height and vertical foliage density) were examined at each site with respect to time since last fire (0.5-10.5 years) and the two recognised microhabitat types (dry and wet). No significant change in species numbers or composition was detected in sites more than 1 year after fire, although the changing physical status (density and cover) of some plants could give the impression of species being 'lost' or 'gained' over time. On the basis of the structural attributes of the heathlands, and the maintenance of several obligate seed regenerator species, a minimum fire-free interval of 8 or 10 years is suggested for subtropical heathlands. Results from this study are compared with data collected from other Australian heathlands. In composition and structure, the temporal responses to fire in the Cooloola heathlands are similar to those in southern heathlands, albeit occurring at a possibly faster rate.
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Groves, RH, PJ Hocking, and A. Mcmahon. "Distribution of Biomass, Nitrogen, Phosphorus and Other Nutrients in Banksia marginata and B. ornata Shoots of Different Ages After Fire." Australian Journal of Botany 34, no. 6 (1986): 709. http://dx.doi.org/10.1071/bt9860709.
Full textAbstract:
The heathland form of Banksia marginata Cav. regenerates rarely from seed but commonly by resprout- ing from buds on lateral roots, whereas Banksia ornata F. Muell. regenerates only from seed, usually released after fire. The two species co-occur in heath vegetation on nutrient-poor soils in south-eastern South Australia and western Victoria. Shoots were sampled from stands of B. marginata aged from 1 to 25 years and of B. ornata aged from 1 to 50+ years after fire in the Little Desert National Park, western Victoria. B. marginata, the resprouter, distributed a greater proportion of the total shoot dry matter and content of all nutrients to vegetative growth over its shorter life span than B. ornata, the non-sprouter. About 50% of the total phosphorus in B. ornata shoots at 50+ years was present in cones (including seeds) compared with only about 20% in B. marginata shoots at a comparable stage of senescence (25 years). This difference between the species was also true to a lesser degree for nitrogen. There were considerable differences between other nutrients in their distribution patterns in shoots. Nutrients could be grouped together on the basis of distribution in shoots more satisfactorily than on presumed physio- logical roles. Stems were major sites of nutrient accumulation in both species. The content of a particular nutrient in seeds as a proportion of the content in the living parts of the shoot ranged from 0.03% (Na, Mn) to 2.0% (P) in B. marginata, and from 0.3% (Na) to as high as 31% (P) in B. ornata. Concen- trations of all nutrients except sodium were much higher in seeds than in the woody cones or vegetative organs of both species; seeds of B. ornata were particularly rich in calcium and manganese. We conclude that the different patterns of distribution of biomass and nutrients, especially nitrogen and phosphorus, within shoots of the two species reflect their different regenerative modes after fire. Introduction Phosphorus and, to a lesser extent, nitrogen limit the growth of sclerophyllous shrubs on nutrient-poor soils in southern Australia
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McCallum, H. I. "Rock-wallaby Biology and Management: Synthesis and Directions for Future Research." Australian Mammalogy 19, no. 2 (1996): 319. http://dx.doi.org/10.1071/am97319.
Full textAbstract:
This paper is a summary and overview of the National Rock-wallaby Symposium held in the Flinders Ranges, South Australia in November/December 1994. Whilst no rock-wallaby taxon of full specific rank is critically endangered, many distinct populations are at immediate risk of extinction. In particular, there is a strong north-south gradient in the conservation status of rock-wallabies. Southern taxa are more threatened than northern taxa, and within species, southern populations are more threatened than northern ones. A clear agenda for future research emerged. Much of this agenda can usefully be placed in the "declining population paradigm" recently identified by Caughley (1994). The threatening process most clearly indicated is predation by foxes, but whether this applies to rock-wallaby populations throughout Australia needs to be determined. Until it is, any manipulations of predation pressure should be treated as experiments. To measure the success of such manipulations, improved methods of population monitoring must be developed. Finally, the level of knowledge about rock-wallabies must be improved, both at the broad scale of taxonomy and distribution, and at the fine scale of detailed studies of the ecology and behaviour of particular populations.
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Gouws, Gavin, Barbara A. Stewart, and Savel R. Daniels. "Phylogeographic structure of a freshwater crayfish (Decapoda:Parastacidae:Cherax preissii) in south-western Australia." Marine and Freshwater Research 57, no. 8 (2006): 837. http://dx.doi.org/10.1071/mf05248.
Full textAbstract:
Although phylogeographic patterns of freshwater decapods elsewhere in Australia are well documented, little is known of the phylogeography and biogeography of the endemic freshwater fauna of south-western Australia. Here, the phylogeographic structure of a freshwater crayfish, Cherax preissii Erichson, 1846, was investigated to determine contemporary and historical patterns of gene flow and to examined evolutionary and biogeographical scenarios. Allozyme and cytochrome c oxidase subunit I mitochondrial DNA data were collected from 15 populations, sampled across the known C. preissii distribution. Both markers revealed a clear distinction and separation among populations occurring in the north-western and southern portions of the distribution. Inferences of allopatric fragmentation and molecular dating attributed the divergence of the aquatic fauna of these regions to periods of Pliocene–Pleistocene aridity. Connectivity appeared to be greater within each of these regions. Evidence suggested contemporary, but not ongoing, gene flow, particularly within the southern region. This was possibly facilitated by dispersal during pluvial Pleistocene periods or drainage connectivity during episodic marine regressions. The divergence and distributions of these lineages parallels patterns seen in other freshwater crayfish of the region. More explicit investigation of these and further fine-scale phylogeographic studies may contribute to the understanding of biogeography and evolution in the south-west, and may further refine currently recognised biogeographical regions.
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Ingleby, S. "Distribution and status of the spectacled hare-wallaby, Lagorchestes conspicillatus." Wildlife Research 18, no. 5 (1991): 501. http://dx.doi.org/10.1071/wr9910501.
Full textAbstract:
Past and present distributions of Lagorchestes conspicillatus were compared using data from museums, explorers' records and from recent field surveys. These data indicated that L. conspicillatus has declined in distribution and abundance during the last century. This species is now rare in the Pilbara and Kimberley regions of Western Australia. It is moderately common between latitudes 16� and 18�S in central and eastern Northern Territory, and its range extends north to around 12�S in Arnhem Land. However, the southern limits of its range in the Northern Territory have contracted northward by over 200 km and it is rarely recorded below 21�S. L. conspicillatus remains widespread in Queensland although its numbers in several areas appear to have declined in the last 10-15 years. The status of L. conspicillatus should be regarded as vulnerable. Most of its preferred habitats are currently under pastoral lease and at risk of alteration by introduced herbivores or clearing. Unfavourable fire regimes and feral animals may also pose a threat to its survival in some areas. Habitats suitable for L. conspicillatus are very poorly represented in National Parks throughout northern Australia and this situation should be rectified.
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Masters, Bernie. "Temperate woodland conservation and management." Pacific Conservation Biology 18, no. 4 (2012): 324. http://dx.doi.org/10.1071/pc120324.
Full textAbstract:
AS excellent as this book is, its title is something of a misnomer. Because the book contains 40 short chapters summarising the key findings and recommendations of many of Australia’s leading woodland researchers and managers, the words ‘Principles of . . . ’ should precede the existing title. While the book provides readers with a very good understanding of the major issues to be addressed in conserving and managing woodland habitat, as well as in producing effective and much-needed government policy, further reading is required from each chapter’s extensive list of references to obtain the detail of how to conserve and manage woodlands. Temperate Woodland Conservation and Management The biodiversity value of woodlands in southern Australia is significant, particularly for bird and bat conservation. Because woodlands soils were suitable for agriculture, between 80 and 90% have been cleared (Thackway, Chapter 31). The remainder is subject to many serious threats including grazing, weeds, fertilizer drift, fragmentation effects and altered fire regimes. This book is a timely summary of relevant research, much of which has been carried out in the last 10 to 15 years.
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Masters, Bernie. "Temperate Woodland Conservation and Management." Pacific Conservation Biology 20, no. 3 (2014): 336. http://dx.doi.org/10.1071/pc140336.
Full textAbstract:
AS excellent as this book is, its title is something of a misnomer. Because the book contains 40 short chapters summarising the key findings and recommendations of many of Australia’s leading woodland researchers and managers, the words “Principles of . . .” should precede the existing title. While the book provides readers with a very good understanding of the major issues to be addressed in conserving and managing woodland habitat, as well as in producing effective and much-needed government policy, further reading is required from each chapter’s extensive list of references to obtain the detail of how to conserve and manage woodlands. The biodiversity value of woodlands in southern Australia is significant, particularly for bird and bat conservation. Because woodland soils were suitable for agriculture, between 80 and 90% have been cleared (Thackway, Chapter 31). The remainder is subject to many serious threats including grazing, weeds, fertilizer drift, fragmentation effects and altered fire regimes. This book is a timely summary of relevant research, much of which has been carried out in the last 10 to 15 years.
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Matley, Kia A., JM Kale Sniderman, Andrew N. Drinnan, and John C. Hellstrom. "Late-Holocene environmental change on the Nullarbor Plain, southwest Australia, based on speleothem pollen records." Holocene 30, no. 5 (January 5, 2020): 672–81. http://dx.doi.org/10.1177/0959683619895589.
Full textAbstract:
Fossil pollen from two stalagmites is examined to reconstruct a c. 2400-year history of vegetation change on the Nullarbor Plain. Environmental changes are reflected by variation in chenopod species abundance, and by a peak in woody taxa between 1000 and 800 years ago which is interpreted as evidence of increased moisture conditions associated with a positive phase of the Southern Annular Mode. While no strong palynological signal is observed at the time of European colonization of Australia, a significant change occurs in the past 40 years, which is interpreted as a vegetation response to a recorded fire event. As speleothems (secondary cave carbonates including stalagmites, stalactites and flowstones) rarely contain enough fossil pollen for analysis, the taphonomic biases of speleothem archives remain poorly understood. This study, as well as being a high-resolution record of environmental change, presents an opportunity to examine these taphonomic filters. The record is shown to be sensitive to episodic deposition of presumably insect-borne pollen, but overall appears to provide a faithful representation of local and regional vegetation change. There is a need for greater research into taphonomic processes, if speleothem palynology is to be developed as a viable alternative to lacustrine sediments in the investigation of past environmental change.
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Truswell, EM. "Vegetation in the Australian Tertiary in Response to Climatic and Phytogeographic Forcing Factors*." Australian Systematic Botany 6, no. 6 (1993): 533. http://dx.doi.org/10.1071/sb9930533.
Full textAbstract:
Nancy Burbidge's 1960 paper on the phytogeography of the Australian region would make a fitting starting point for a review of the impact of the plant fossil record on understanding Australian vegetation history. However, a number of reviews were published in the late 1970s and early 1980s, so that the present overview takes its starting point from that time and considers the advances in research since then. In the interval since, information has accrued from both palynology and plant macrofossils, so that the fossil evidence must now be considered a primary source of data for interpreting the evolution of Australian vegetation. There have also been major advances in understanding the geological framework of the Tertiary, against which the fossil data must be set. For instance, the timescale against which advances must be measured has been refined, there have been comprehensive syntheses of Tertiary palaeogeography, and a better understanding of the relationships, through time, of Australia with continents to the north, and between Australia and Antarctica. Our understanding of the climatic factors affecting the continent and its vegetation has also improved. The record now available, in spite of its many limitations, gives a general picture of transition from widespread, very diverse rainforests in the early Tertiary, to predominantly open vegetation with rainforest restricted to wetter regions. Some aspects of the early forests remain insufficiently understood; for instance, the effects of high latitude position on forest growth. The development of sclerophylly may go back as far as the Eocene, with Banksia and Acacia now having records that extend back that far. The development of open vegetation types was probably linked with changing fire regimes; we know that by the mid-Miocene, heath-like vegetation was established locally in coal swamps. Rainforests of drier aspect were established early too, probably first at inland localities, and there are hints of wet sclerophyll forest by the late Miocene. The history of grasslands and savannah remains sketchy, and no modem analogues can be identified for vegetation types in the Pliocene that were rich in Asteraceae and grasses. The history of the eucalypts, and their links to specific fire regimes, is a more recent story.* The Nancy Burbridge Memorial Lecture, which was presented at the 'Southem Temperate Ecosystems' conference, held in Hobart, Tasmania, 18–22 January 1993.
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Shaddick, Kim, Dean M. Gilligan, Christopher P. Burridge, Dean R. Jerry, Kiet Truong, and Luciano B. Beheregaray. "Historic divergence with contemporary connectivity in a catadromous fish, the estuary perch (Macquaria colonorum)." Canadian Journal of Fisheries and Aquatic Sciences 68, no. 2 (February 2011): 304–18. http://dx.doi.org/10.1139/f10-139.
Full textAbstract:
The estuary perch ( Macquaria colonorum ) represents an important model for assessing how historical changes in coastal geomorphology and current oceanographic and estuarine conditions may have impacted connectivity in a catadromous fish. A fragment of the mitochondrial control region and six microsatellite DNA markers were used to clarify connectivity in 17 populations (n = 354) of estuary perch from the southeast and southern coasts of Australia. The mtDNA data showed a latitudinal disjunction in haplotype frequencies that divided populations into two groups (ΦST = 0.419), in a pattern suggestive of isolation by geographic distance. However, no marked structure or correlation with distance was apparent within each group, a result consistent with microsatellite data that showed high contemporary population connectivity across large distances. This was contrary to expectations that the species would exhibit moderate to strong genetic structure consistent with a one-dimensional stepping stone pattern. Coalescent phylogeographic and population genetic analyses provided support for a historical divergence probably due to the emergence of the Bassian Isthmus in southern Australia. Current connectivity appears to be maintained by both large- and fine-scale oceanographic currents and processes, highlighting the important role of the marine environment for an estuarine resident species.
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Braithwaite, RW, and AD Griffiths. "The Paradox of Rattus Tunneyi: Endangerment of a Native Pest." Wildlife Research 23, no. 1 (1996): 1. http://dx.doi.org/10.1071/wr9960001.
Full textAbstract:
An analysis of mark-recapture data for Rattus tunneyi in Kakadu National Park from a 7-year period was performed. Capture rates declined 500-fold during this period. The species exhibits a strong preference for riparian vegetation. The diet is primarily herbivorous, with little insect material. High-nutrient plant parts are generally chosen. Reproduction is most common in the wet season but some breeding extends throughout the year if unseasonal rain occurs during the dry season. Fire regime seems to have little effect on population numbers. The level of groundwater irrigating the riparian system and to a lesser extent current rainfall have a much stronger influence. Museum records show a contraction since European colonization from a near-total continental distribution to one-seventh of its former distribution along the north-west Australian and southern Queensland coast. The contraction from the more arid regions is likely to be due to the impact of introduced mammalian herbivores on the riparian habitats which previously functioned as refuge areas during periods of low water availability. Historically, R. tunneyi is likely to have fluctuated in distribution and abundance throughout the continent. In recent times, this has included irruptions into commercial crops in some areas. The loss of local refuges plus relatively poor powers of dispersal have resulted in the distribution now being fragmented, with the north-western and central east coasts of Australia providing the most significant habitat for the species.
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Norton, Melinda A., Andrew W. Claridge, Kris French, and Alison Prentice. "Population biology of the long-nosed potoroo (Potorous tridactylus) in the Southern Highlands of New South Wales." Australian Journal of Zoology 58, no. 6 (2010): 362. http://dx.doi.org/10.1071/zo10075.
Full textAbstract:
The population biology of the long-nosed potoroo (Potorous tridactylus) was investigated at Barren Grounds Nature Reserve and Budderoo National Park in the Southern Highlands of New South Wales (NSW). Both study areas are important conservation reserves for this threatened species, with a large gap north (~300 km) to the next known viable population on the mid-north coast of NSW at Mount Royal. Potoroos were live-trapped using bandicoot-sized cage traps, each set ~100 m apart along walking tracks and fire trails. Trapping was conducted each autumn and spring over five years to enumerate the local population of potoroos and to describe their morphometrics. The local long-nosed potoroos were larger in size than those recorded to the south on mainland Australia, but smaller than those in north-eastern NSW, supporting the concept of a latitudinal cline in body size. Sexual dimorphism was observed, with adult males having larger body weights, head lengths and pes lengths. Between one-third and two-thirds of all males and females were captured in only a single trapping session, indicative of low levels of survivorship and/or high levels of dispersal or transience. Males regularly overlapped at trap sites with females, more so than with other males, while females rarely overlapped at trap sites. Barren Grounds Nature Reserve supported a larger number of potoroos and a greater degree of home range overlap between individuals.
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Meney, K. A., K. W. Dixon, and J. S. Pate. "Reproductive Potential of Obligate Seeder and Resprouter Herbaceous Perennial Monocots (Restionaceae, Anarthriaceae, Ecdeiocoleaceae) from South-western Western Australia." Australian Journal of Botany 45, no. 5 (1997): 771. http://dx.doi.org/10.1071/bt96028.
Full textAbstract:
Pre- and post-dispersal reproductive success was studied in 22 species from three related Southern Hemisphere families, Restionaceae, Ecdeiocoleaceae and Anarthriaceae. Pre-dispersal success was compared for resprouter and obligate seeder species using seed: ovule ratios and carpel: flower ratios. The data indicated a high level of variability between taxa but pre-dispersal reproductive success of obligate seeders was significantly higher (67% conversion of ovules to seeds) than that of resprouters (35%). Two seeders, an extremely rare species (‘Chordifex’ abortivus) and a strongly clonal species (Alexgeorgea subterranea), showed pre-dispersal reproductive success values lower than or equal to the mean value for resprouters. Post-dispersal reproductive success was predicted in terms of proportions of germinable seeds produced per ovule (as determined by in vitro germination of isolated embryos). Data again varied widely between taxa, averaging 23% conversion of ovules to seeds with no clear relationship to regeneration mode. The mean number of germinable seeds per culm ranged from 0.03 to 21 between species, with cases of particularly low ovule output and/or low germinability in critically low germinable seed numbers for a species. The regeneration potential of a subset of species was assessed as mean annual production of germinable seed per reproducing plant of a population. The data indicated low values (less than eight seeds per adult) for all but three highly fecund species, suggesting that germinable seed output in some species might be scarcely able to compensate for natural senescence or catastrophic loss of parent populations (e.g. after fire, disease, increased competition following eutrophication).