The effects of experimental patch burning and rainfall on small mammals in the Simpson Desert, Queensland
An article from Wildlife Research 30, written by Mike Letnic, published in 2003. [pdf 453.8 kb]
Patch Mosaic Burning for Biodiversity Conservation: a Critique of the Pyrodiversity Paradigm
Fire management is increasingly focusing on introducing heterogeneity in burning patterns under the assumption that “pyrodiversity begets biodiversity.” This concept has been formalized as patch mosaic burning (PMB), in which fire is manipulated to create a mosaic of patches representative of a range of fire histories to generate heterogeneity across space and time. Although PMB is an intuitively appealing concept, it has received little critical analysis. Thus we examined ecosystems where PMB has received the most attention and has been the most extensively implemented: tropical and subtropical savannas of Australia and Africa.
We identified serious shortcomings of PMB: the ecological significance of different burning patterns remains
unknown and details of desired fire mosaics remain unspecified. This has led to fire-management plans based on pyrodiversity rhetoric that lacks substance in terms of operational guidelines and capacity for meaningful evaluation.We also suggest that not all fire patterns are ecologically meaningful: this seems particularly true for the highly fire-prone savannas of Australia and South Africa. We argue that biodiversity-needs-pyrodiversity advocacy needs to be replaced with a more critical consideration of the levels of pyrodiversity needed for biodiversity and greater attention to operational guidelines for its implementation. [pdf 305.1 kb]
Contemporary fire regimes of northern Australia, 1997-2001: change since Aboriginal occupancy, challenges for sustainable management
A report from International Journal of Wildland Fire 12, published in 2003. [pdf 1.3 Mb]
Fire Management in the Rangelands
A report to the Australian Government Department of Environment and Heritage prepared by the Tropical Savannas and Desert Knowledge Cooperative Research Centres. [pdf 1.4 Mb]
Fire and its management in central Australia
Over the last 130 years, patterns of land use in central Australia have altered dramatically, and so too have fire regimes and fire management objectives. Although Aboriginal people still have tenure over large parts of the landscape, their lifestyles have changed. Most Aboriginal people now live in towns and settlements and, although fire management is still culturally important, the opportunities for getting out on country to burn are constrained. Large parts of the landscape are now used for pastoral production. Under this land use the management objective is often one of fire exclusion. The other large-scale land use is for conservation. Here, fire management has a greater focus on conserving biodiversity using various burning strategies. In this paper we explore contemporary fire regimes in central Australia. Widespread fire events are found to be associated with two or more consecutive years of above-average rainfall. Although most of the fires linked with these high rainfall periods occur during the warmer months, in recent times these fires have exhibited increased activity during the cooler months. There has been a concomitant increase in the number and size of these fires and in the number of fires associated with roads. We also explored current fire management issues on Aboriginal, pastoral and conservation lands. Current fire management goals are not being wholly met on any of these land tenures in central Australia and social conflict sometimes emerges as a result. There are overlaps in management aims, issues and the underachievement of desired outcomes across the land tenures which lead us to five key recommendations for improving fire management outcomes in central Australia. We finish with some comments on associated opportunities for livelihood enhancement based on the management of fire. [pdf 511.9 kb]
Bushfires ‘down under’: patterns and implications of contemporary Australian landscape burning
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 km2AdvancedVery 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. [pdf 1.1 Mb]
Fire studies in Mallee (eucalypt us spp.) Communities of western New South Wales: grass fuel dynamics and associated weather patterns
This paper records data on the spatial distributions of different fuels, plant architecture and post-fire seedling recruitment and survivorship of T. scariosa, obtained during field studies on contrasting mallee sites in western New South Wales. In addition, rainfall data extending over c. 100 years were used in a water balance study at one mallee site (Pooncarie); while similar rainfall data were analysed for three mallee sites (Pooncarie, Ivanhoe and Mount Hope) using a filter technique to examine quasiperiodicities of rainfall and potential correlations with known wildfire seasons in the past. [pdf 1.5 Mb]
Global characterization of fire activity: toward defining fire regimes from Earth observation data
There is interest in the global community on how fire regimes are changing as a function of changing demographics and climate. The ground-based data to monitor such trends in fire activity are inadequate at the global scale. Satellite observations provide a basis for such a monitoring system. In this study, a set of metrics were developed from 6 years of MODIS active fire data. The metrics were grouped into eight classes representing three axes of fire activity: density, season duration and interannual variability. These groups were compared with biophysical and human explanatory variables on a global scale. We found that more than 30% of the land surface has a significant fire frequency. The most extensive fire class exhibited high fire density, low duration and high variability and was found in boreal and tropical wet and dry environments. A high association was found between population distribution and fire persistence. Low GDPkm2 was associated
with fire classes with high interannual variability and low seasonal duration. In areas with more economic resources, fires tend to be more regular and last longer. High fire duration and low interannual variability were associated with croplands, but often with low fire density. The study was constrained by the limited length of satellite data record but is a first step toward developing a comprehensive global assessment of fire regimes. However, more attention is needed by the global observing systems to provide the underpinning socio-economic observations to better quantify and analyze the human characteristics of fire regimes. [pdf 615.3 kb]
INTEGRATED SHRUB MANAGEMENT IN SEMI-ARID WOODLANDS OF EASTERN AUSTRALIA: EFFECTS OF CHEMICAL DEFOLIANTS APPLIED AFTER AN INITIAL DISTURBANCE
Previous fire experiments using artificial fuel have shown that annual fires, especially those applied in the autumn, can effectively control coppicing understorey shrubs in semi-arid woodlands. Such frequent fire is impossible to apply under natural conditions given the limited time available for sufficient herbage fuel to accumulate. Preliminary screening studies were therefore undertaken to test the hypothesis that chemical sprays applied at concentrations less than those normally recommended could be used to mimic highfrequency experimental fires. The effectiveness of 11 chemicals (7 arboricides and 4 dessicants) applied at a range of concentrations was assessed on one site by spot-spraying 5-year-old coppice regeneration of E~demophila mitchellii (budda or false sandalwood) and E. stuvtii (turpentine). Chemical activity was assessed by regularly monitoring leaf effect, i.e. by rating the degree of leaf discolouration, scorching, blackening and ultimately leaf fall, over the ensuing 12 months following treatment. Arsenal@ and Roundup CTO induced the highest shrub mortalities across all size classes while mortality rates were consistently higher for E. mitchellii than for E. sturtii. A second experiment involved 5 chemicals (4 arboricides and 1 dessicant) applied in a similar manner to 7-year-old seedlings of Cassia nemophila (syn. Senna nemophila) (punty bush). Significant damage to foliage (> 80% leaf effect) of all 3 shrub species was recorded 2 months after treatment with either Roundup CTO or Roundup@ (i.e. either 450 or 360 g/L glyphosate respectively), as well as with ArsenalO (250 g/L imazapur + 60 g/L isopropylamine) but only at the highest concentration (i.e. 100% of the 'recommended' rate). In some lower concentration treatments. leaf effect was still increasing 6 months after treatment.
In a second series of screening experiments involving 1- and 2-year-old coppices sprayed in autumn and spring, significant interaction occurred between coppice age and season of spraying when averaged over both Eremophila species. At lower concentrations (i.e. 12.5 and 25% of maximum recommended rate), autumn application of Roundup CTO was more effective than spring application, especially once regeneration was 2 years old. GramoxoneO was also most effective at all rates above 12.5% of the maximum when applied in the autumn to two-year-old coppice. However, GarlonO (600 g/L triclopyr) and Tordon 50-DO (50 g/L picloram + 200 g/L 2,4-D) were more effective when applied to I -year-old coppice in the spring. Overall, the most effective low-concentration treatment was Roundup CTO applied in the autumn to two-year-old coppice. Low-concentration treatment of one-year-old coppice with Roundup CTO and ArsenalO was also consistently more effective when carried out in the autumn (80-90% leaf effect).
The probability of shrub mortality was inversely related to coppice biomass with smaller coppices clearly more vulnerable to the added pressure imposed by secondary chemical treatment, independent of application rate. [pdf 1.5 Mb]
The effects of fire on the soil in a degraded semi-arid woodland- susceptibility of the soil to erosion by shallow rain-impacted flow
The results of a study conducted by R.S.B. Greene, C.J. Chartres and K.C. Hodgkinson on the effects of fire on the soil in a degraded semi-arid woodland. This document details the study focusing on the susceptibility of the soil to erosion by shallow rain-impacted flow. [pdf 5.3 Mb]
