Academic literature on the topic 'Fire ecology Victoria'

Wildland fires attributed to lightning ignitions in Victoria, Australia, are examined systematically through the use of lightning occurrence data. Lightning stroke data were obtained by a network of ground-based lightning detection sensors over a 9-year period. Characteristics of these fires are examined including the temporal variability in the average chance of fire occurrence per lightning stroke and the time period from lightning ignition of a fire until the fire grows large enough to be first observed, as well as distributions of fire duration and total area burnt. It is found that the time of day that lightning occurs does not have a significant influence on the chance of fire per lightning stroke, in contrast to the time of year, for which a significant annual variation occurs. Regional variability is examined by discussing the results for Victoria, Australia, in relation to results of studies from other parts of the world.

In the trend towards the domestication, or taming, of fire regimes in Victoria, Australia, the level of prescribed burning has been stepped up due to a recommendation from the 2009 Victorian Bushfires Royal Commission. While prescribed burning programs may be instituted for a number of reasons, especially the protection of life and property, they have consequences for the conservation of biodiversity. Not all vegetation types can be prescribed burned because the weather does not always allow it to occur under safe working conditions; where prescribed burning programs are carried out, unplanned fires may still occur. Thus, the general issue is the effect on biodiversity of both prescribed and unplanned fires, neither alone. Here, the importance to biodiversity conservation of all the components of the fire regime– interval, season, intensity and type (peat fire or otherwise) – and their domain of variability is emphasized. If conservation of biodiversity is to be guaranteed in a changing fire world, then much more knowledge about the systems being managed, gained in large part through effective monitoring, is needed. Issues such as targets and some assumptions of management are addressed here.

McArthur's Fire Danger Indices were developed originally as empirical models to describe fire danger in dry sclerophyll forest and grasslands of Australia. These indices are now used widely in southeastern Australia for fire danger rating and as a guideline for the issue of fire weather warnings. Nine years of historical fire reports, fire danger indices and meteorological information have been analysed objectively to develop a model to predict days of high fire activity in the mallee shrubland of northwestern Victoria. Tested on two years of independent data it was found that the use of a simple model utilising standard meteorological observations rather than the McArthur Forest Fire Danger Index reduced the false alarm rate from 98.4% to 96.7%. Although apparently a small reduction in false alarm rate, over a two year period days of high fire activity predicted incorrectly were reduced dramatically by 345 days.

Birds and reptiles were censused at two sites of contrasting soil texture (clay, loam) on pastoral land in the Victoria River District, Northern Territory. Both sites comprised 16 plots (each of 2.6 ha) subjected to seven different experimental fire regimes (unburnt, burnt in the early dry season at 2, 4 and 6 year intervals, and burnt in the late dry season at 2, 4 and 6 year intervals) beginning five years before sampling (and thus, not all regimes had been operationally distinct between the onset of the experiment and this sampling). The regimes were deconstructed to four fire factors: the imposed regime, the time since last fire, the number of fires since the inception of the experiment, and the number of hot (=late dry season) fires. Of 30 species recorded from at least four plots, 12 were significantly associated with time since last fire. These responses were mostly to the extremes - some species were associated with the most recently burnt areas, and others occurred mainly in the plots which had been unburnt the longest. Longer- term responses to fire regimes were generally less clearcut, possibly because the relatively short duration of the imposed experimental fire treatments had not yet brought about substantial environmental divergence. Key words: fire regime, tropical savannas, birds, reptiles, diversity.

Considerable research has been undertaken over the past two decades to apply remote sensing to the study of fire regimes across the savannas of northern Australia. This work has focused on two spatial scales of imagery resolution: coarse-resolution NOAA-AVHRR imagery for savanna-wide assessments both of the daily distribution of fires ('hot spots'), and cumulative mapping of burnt areas ('fire-scars') over the annual cycle; and fine-resolution Landsat imagery for undertaking detailed assessments of regional fire regimes. Importantly, substantial effort has been given to the validation of fire mapping products at both scales of resolution. At the savanna-wide scale, fire mapping activities have established that: (1) contrary to recent perception, from a national perspective the great majority of burning in any one year typically occurs in the tropical savannas; (2) the distribution of burning across the savannas is very uneven, occurring mostly in sparsely settled, higher rainfall, northern coastal and subcoastal regions (north-west Kimberley, Top End of the Northern Territory, around the Gulf of Carpentaria) across a variety of major land uses (pastoral, conservation, indigenous); whereas (3) limited burning is undertaken in regions with productive soils supporting more intensive pastoral management, particularly in Queensland; and (4) on a seasonal basis, most burning occurs in the latter half of the dry season, typically as uncontrolled wildfire. Decadal fine-resolution fire histories have also been assembled from multi-scene Landsat imagery for a number of fire-prone large properties (e.g. Kakadu and Nitmiluk National Parks) and local regions (e.g. Sturt Plateau and Victoria River District, Northern Territory). These studies have facilitated more refined description of various fire regime parameters (fire extent, seasonality, frequency, interval, patchiness) and, as dealt with elsewhere in this special issue, associated ecological assessments. This paper focuses firstly on the patterning of contemporary fire regimes across the savanna landscapes of northern Australia, and then addresses the implications of these data for our understanding of changes in fire regime since Aboriginal occupancy, and implications of contemporary patterns on biodiversity and emerging greenhouse issues.

Fire management agencies use fire behaviour simulation tools to predict the potential spread of a fire in both risk planning and operationally during wildfires. These models are generally based on underlying empirical or quasi-empirical relations and rarely are uncertainties considered. Little attention has been given to the quality of the input data used during operational fire predictions. We examined the extent to which error in weather forecasts can affect fire simulation results. The study was conducted using data representing the State of Victoria in south-eastern Australia, including grassland and forest conditions. Two fire simulator software packages were used to compare fire growth under observed and forecast weather. We found that error in the weather forecast data significantly altered the predicted size and location of fires. Large errors in wind speed and temperature resulted in an overprediction of fire size, whereas large errors in wind direction resulted in an increased spatial error in the fire’s location. As the fire weather intensified, fire predictions using forecast weather under predicted fire size, potentially resulting in greater risks to the community. These results highlight the importance of on-ground intelligence during wildfires and the use of ensembles to improve operational fire predictions.

The fires of summer 2003 in south-eastern Australia burnt tens of thousands of hectares of treeless alpine landscape. Here, we examine the environmental impact of these fires, using data from the Bogong High Plains area of Victoria, and the Snowy Mountains region of New South Wales. Historical and biophysical evidence suggests that in Australian alpine environments, extensive fires occur only in periods of extended regional drought, and when severe local fire weather coincides with multiple ignitions in the surrounding montane forests. Dendrochronological evidence indicates that large fires have occurred approximately every 50–100 years over the past 400 years. Post-fire monitoring of vegetation in grasslands and heathlands indicates that most alpine species regenerate rapidly after fire, with >90% of species present 1 year after fire. Some keystone species in some plant communities, however, had not regenerated after 3 years. The responses of alpine fauna to the 2003 fires were variable. The core habitat (closed heathland) of several vulnerable small mammals was extensively burnt. Some mammals experienced substantial falls in populations, others experienced substantial increases. Unburnt patches of vegetation are critical to faunal recovery from fire. There was, however, no evidence of local extinction. We conclude that infrequent extensive fires are a feature of alpine Australia. For both the flora and fauna, there is no quantitative evidence that the 2003 fires were an ecological disaster, and we conclude that the flora and fauna of alpine Australia are highly resilient to infrequent, large, intense fires.

Most of the life and property losses due to bushfires in south-eastern Australia occur under extreme fire weather conditions – strong winds, high temperatures, low relative humidity (RH) and extended drought. However, what constitutes extreme, and the values of the weather ingredients and their variability, differs regionally. Using a gridded dataset to identify the highest 10 fire weather days from 1972 to 2012, as defined by McArthur’s Forest Fire Danger Index (FFDI), for 24 sites across Victoria and nearby, we analyse the extent and variability of these highest 10 FFDI days, and of the contributing temperature, RH, wind speed, wind direction and drought indices. We document the occurrence of these events by time of day, month of occurrence and inter-annual variability. We find there is considerable variability among regions in the highest FFDI days and also the contributing weather and drought parameters, with some regional groupings apparent. Many major fire events occurred on these highest 10 fire weather days; however there are also days in which extreme fire weather occurred yet no known major fires are recorded. The results from this study will be an additional valuable resource to fire agencies in fire risk planning by basing fire management decisions on site-specific extreme fire weather conditions.

Box-Ironbark forests extend across a swathe of northern Victoria on the inland side of the Great Dividing Range. Although extensively cleared and modified, they support a distinctive suite of plants and animals. Historical fire regimes in this ecosystem are largely unknown, as are the effects of fire on most of the biota. However, knowledge of the ecological attributes of plant species has been used to determine minimum and maximum tolerable fire intervals for this ecosystem to guide current fire management. Here, we consider the potential effects of planned fire in the context of major ecological drivers of the current box-ironbark forests: namely, the climate and physical environment; historical land clearing and fragmentation; and extractive land uses. We outline an experimental management and research project based on application of planned burns in different seasons (autumn, spring) and at different levels of burn cover (patchy, extensive). A range of ecological attributes will be monitored before and after burns to provide better understanding of the landscape-scale effects of fire in box-ironbark forests. Such integration of management and research is essential to address the many knowledge gaps in fire ecology, particularly in the context of massively increased levels of planned burning currently being implemented in Victoria.

On Saturday 7 February 2009, 173 people lost their lives and more than 2000 houses were destroyed in bushfires (wildfires) in the Australian State of Victoria. The scale of life and property loss raised fundamental questions about community bushfire safety in Australia, in particular the appropriateness of the ‘Prepare, stay and defend or leave early’ policy. This paper presents findings from research undertaken as part of the Australian Bushfire Cooperative Research Centre’s (CRC) ‘2009 Victorian Bushfires Research Taskforce’. The research examined factors influencing patterns of life and property loss and survival across the fires through mail surveys (n=1314) of fire affected households. Just over half of the respondents (53%) stayed to defend their homes and properties, whereas the remainder left before or when the fires arrived (43%) or sheltered in a house, structure, vehicle, or outside (4%). Results reveal a survival rate of 77% for houses that were defended by one or more household members, compared to 44% for unattended houses. The paper identifies inadequate planning and preparedness and the tendency for people to wait until they are directly threatened before taking action as major factors leading to late evacuation, failed defence and passive shelter.

The relationship of vegetation and disturbance factors to the distribution, abundance and diversity of small mammals in the eastern Otway region, Victoria were investigated. Antechinus stuartii, Rattus fuscipes and Rattus lutreolus were widely distributed and occurred in the majority of the eleven floristic vegetation groups identified. Antechinus minimus, Antechinus swainsonnii and Pseudomys novaehollandiae had restricted distributions and were recorded in only two or three vegetation groups. New information on the distribution of the rare species P. novaehollandiae, was obtained and two floristically rich vegetation groups that it preferred were identified. Species-rich small mammal communities occurred in vegetation communities with high numbers of sclerophyll plant species and high structural diversity. Maximum food resources were considered to be provided in these communities. Local habitat diversity was also correlated with species-richness. Small mammal abundance was maximum in non-sclerophyllous canmunities, where high plant productivity was considered to be important. For the first time, the presence of the plant pathogen Phytophthora cinnamomi was shown to affect small mammals. It was associated with small mammal communities of low species richness and abundance, Recovery of small mammal populations after wildfire was slow until the fourth year. Mus musculus reached peak abundance from 2-3 years and then declined rapidly. P. novaehollandiae was the only native species that achieved maximum abundance early in the succession. A. stuartii, R. fuscipes and R. lutreolus approached maximum abundance in mid-succession, while Isoodon obesulus was a mid- to late-successional species. A. minimus survived the fire, but did not persist after one year. The pattern of succession was influenced by attributes of species, such as survival after fire, their ability to disperse and reproduce.

The spatial and temporal pattern of fire occurrence within landscapes is a principal factor influencing species distributions and a core driver of biodiversity. However, climate change, land use change, invasive species and detrimental land management practices are altering the distribution, frequency, scale and intensity of large wildfires globally. This poses a major challenge to biodiversity management as ecosystems adapt to novel patterns of fire occurrence. Within fire-affected landscapes, areas which experience unique disturbance regimes may act as refuges for biota, reducing the impacts of fire on species and increasing their likelihood of survival. However, very few studies have attempted to quantify the desirable spatial attributes of such areas within fire mosaics for faunal conservation. This thesis aimed to quantify the ecological role of fire refuges by examining the factors responsible for refuge establishment, how the spatial properties of refuges influence their use by fauna, and the mechanisms underpinning faunal responses. To investigate the factors responsible for the spatial distribution of fire refuges in montane forests I tested the operational validity of a pre-constructed fire simulation model with actual fire severity patterns produced following a large fire in the modelled landscapes. I found that for fires which occurred in extreme fire conditions, severity patterns were largely determined by stochastic factors, such as weather. When fire conditions were moderate, physical landscape properties appeared to mediate fire severity distribution. The study highlighted that fire refuges are a potentially ecologically important outcome of large wildfires. I recommend that detrimental land management practices are minimized to enable the ecological processes relevant to the establishment and subsequent use of fire refuges to be maintained. In recently burnt Mountain Ash forests in south-eastern Australia, I examined how fire severity, patch size and landscape context influenced the abundance of arboreal marsupials. We aimed to determine if fire refuges are an important mechanism for facilitating the survival within extensively burnt landscapes. I found the mountain brushtail possum had a positive response to a particular kind of topographic refuge (unburnt peninsulas connected to larger areas of unburnt forest), whereas the greater glider had a negative response to fire in the landscape. The study highlighted the need for a more developed understanding of how post-fire habitat patterns facilitate species survival within burnt landscapes. In a correlative landscape-scale study, I examined how bird use of potential refuges was influenced by 1) the size and connectivity of each refuge, 2) the extent of fire severities at different scales in the surrounding landscape, and 3) the interaction between severity patterns, vegetation structure and environmental gradients. I found that unburnt mesic gullies facilitated the retention of forest birds within extensively burnt montane forest landscapes. The study presented a key advance, in that the effects of fire-induced habitat patterns on the distribution of fauna varied between areas depending on their spatial relationships with key biotic and abiotic landscape patterns. I demonstrated that developing contingent theory by examining ecological interactions between fire induced habitat patterns and biotic and abiotic gradients is essential to understanding complex faunal responses to fire. Using GPS telemetry within a replicated landscape scale study design, I examined how the spatial patterns of fire severity created by a large wildfire influenced the spatio temporal movement patterns of an arboreal marsupial, the Mountain Brushtail Possum, Trichosurus cunninghammi. I found a difference in temporal movement dynamics, habitat selection and spatial movement patters between forested landscapes which were burnt to differing extents. Forest systems recently burnt at high severity may provide suitable habitat for some species, if protected from subsequent disturbance such as salvage logging. However, spatial and temporal patterns of habitat selection and use differed considerably between burnt and undisturbed landscapes. The spatial outcomes of ecological disturbances such as wildfires have the potential to alter the behaviour and functional roles of fauna across large areas. Employing a qualitative research approach, I identified the barriers and enablers to spatially managing fire for biodiversity. I then developed a conceptual framework and set of key steps to achieve the integration of spatial approaches to fire into management. I identified that spatial approaches to fire management must co-exist within a complex system of social and ecological feedbacks between landscapes, academic research, socio-political land management systems, and environmental pressures. I suggest that the integration of spatial approaches to fire can be achieved by developing community understanding of fire science, improving the relevance of fire research outputs to land management, amending existing government policy approaches and refining management tools, structures, scales and monitoring to meet biodiversity and fire risk objectives. The insights into fire refuge ecology provided by the papers in this thesis are highly relevant to faunal conservation. Collectively, this thesis constitutes an important contribution to global forest fire ecology and management and has implications for both understanding the impacts of ecosystem disturbances on faunal persistence and distributions, and for developing effective future research and conservation strategies.

The conservation of Earth's forest ecosystems is one of the great environmental challenges facing humanity in the 21st century. All of Earth's ecosystems now face the spectre of the accelerated greenhouse effect and rates of change in climatic regimes that have hitherto been unknown. In addition, multiple use forestry – where forests are managed to provide for both a supply of wood and the conservation of biodiversity – can change the floristic composition and vegetation structure of forests with significant implications for wildlife habitat. Wildlife, fire and future climate: a forest ecosystem analysis explores these themes through a landscape-wide study of refugia and future climate in the tall, wet forests of the Central Highlands of Victoria. It represents a model case study for the kind of integrated investigation needed throughout the world in order to deal with the potential response of terrestrial ecological systems to global change. The analyses presented in this book represent one of the few ecosystem studies ever undertaken that has attempted such a complex synthesis of fire, wildlife, vegetation, and climate. Wildlife, fire and future climate: a forest ecosystem analysis is written by an experienced team of leading world experts in fire ecology, modelling, terrain and climate analysis, vegetation and wildlife habitat. Their collaboration on this book represents a unique and exemplary, multi-disciplinary venture.

Chapter 4 makes the case that the work of Eliot and Lewes exemplifies a pragmatist understanding of knowledge that is centred on the idea of “experience as experiment” (Jay) or “experience as a craft” (Sennett). Distinguishing between two main senses of ‘experience’, practical wisdom and intense awareness, the chapter traces the manifold implications of that term through G.H. Lewes’s five volume fragment Problems of Life and Mind, Samuel Butler’s Life and Habit and George Eliot’s The Spanish Gypsy. Moreover, close readings of these texts are interwoven with references to the philosophical tradition of American Pragmatism, as represented by the work of William James and John Dewey. Briefly, my main argument is that these Pragmatist writers shared with their Victorian predecessors an ecological view of experience as an incipient pattern, an advancing middle between the past and the future as well as inside and outside, or subject and object, that essentially lacks anything like a firm ground.