Changes in southwestern Tasmanian fire regimes since the early 1800s

There have been major changes in the fire regime of southwestern Tasmania over the past 170 years. The fire regime has changed from an Aboriginal fire regime of frequent low-intensity fires in buttongrass moorland (mostly in spring and autumn) with only the occasional high-intensity forest fire, to the early European fire regime of frequent high-intensity fires in all vegetation types, to a regime of low to medium intensity buttongrass moorland fires and finally to the current regime of few fires. These changes in the fire regime resulted in major impacts to the region's fire-sensitive vegetation types during the early European period, while the current low fire frequency across much of southwestern Tasmania has resulted in a large proportion of the region's fire-adapted buttongrass moorland being classified as old-growth. These extensive areas of old-growth buttongrass moorland mean that the potential for another large-scale ecologically damaging wildfire is high and, to avoid this, it would be better to re-introduce a regime of low-intensity fires into the region

Reconnaissance survey of a glaucous eucalypt near Louisa Bay, southwestern Tasmania

Stands of a glaucous eucalypt in the vicinity of Louisa Bay, southwestern Tasmania, which has affinities to Eucalyptus tenuiramis (Series Piperitae), were surveyed in order to determine their taxonomic status and record aspects of their population ecology. Two main populations were observed in scattered stands among predominantly moorland vegetation at the Red Point Hills and Louisa Plains. One stand from each population was accessed for detailed study. Contiguous plots located along transects across the copses were used to record changes in population status, floristics and site conditions. Individuals of the glaucous eucalypt were small in stature and frequently malleeform near the moorland boundary, but were taller (10-12 m) and straight with single, slender main stems toward the centre of the copse. The Red Point Hills stand comprised a larger number of smaller individuals than the Louisa Plains stand and had been subject to at least three fires in the last 65 years, whereas only one fire had occurred on the Louisa Plains in the same period. These observations have implications for fire management: an appropriate regime, which encourages regeneration around the stand margins rather than increasing the edge-effects, needs to be devised. Given the geographic discontinuity with Eucalyptus tenuiramis, the southwestern copses may represent a relict dry sclerophyll community that was once contiguous with eastern Tasmania during the height of the last glaciation

Fire history of the northern part of the Tasmanian Wilderness World Heritage Area and its associated regions

Fire history (from the 1820s to 2000) in the northern quarter of the Tasmanian Wilderness World Heritage Area and its associated regions is discussed in this paper. This area includes Cradle Mountain-Lake St Clair National Park, Granite Tor Conservation Area, Walls of Jerusalem National Park and the Central Plateau Conservation Area west of Great Lake. In common with fire history in southwest Tasmania, there have been major changes in fire regimes during the last 180 years, with major fires in the 1890s (most probably in 1896-97 or 1897-98 or both) and the 1930s (most probably in 1933-34). However, in contrast to southwest Tasmania, there were major fires until the early 1960s: in the early 1950s in the Cradle Mountain-Lake St Clair National Park and Granite Tor Conservation Area, and in 1960-61 in the Walls of Jerusalem National Park and the Central Plateau Conservation Area. Between the 1930s and 1960s over 40% of the study area or about 129 000 ha was burnt. About half of the study area's fire-sensitive vegetation (i.e., alpine, subalpine heath, subalpine rainforest, rainforest and native conifer) was burnt in these fires. The last of these fires - the 1960-61 Central Plateau fire was the biggest and most destructive fire in the World Heritage Area since the 1930s. Less than 3% of the study area was burnt between 1970 and 2000

Regeneration characteristics of a swamp forest in northwestern Tasmania

The botanical composition and regeneration characteristics are described for a Melaleuca ricifoliaLeptospermum lanigerum forest from northwestern Tasmania. The size classes of the two dominant species are highly correlated with tree age. Size class analysis shows that the dominants are regenerating continuously. The relationship of this forest type to rainforest and wet sclerophyll forest are discussed

Impact of changes in lightning fire incidence on the values of the Tasmanian wilderness world heritage area

The Tasmanian Wilderness World Heritage Area has ecosystems and cultural landscapes that have been created and/or influenced by the interactions between the physical environment, the biological environment, fire regimes and people. Lightning is the dominant cause of fire in the 2010s, yet was rarely recorded as a cause of fire before 1980, when arsonists caused most fires. The main potential impact of this change in primary cause of fire incidence on the values of the Tasmanian Wilderness World Heritage Area is the loss of ecosystems dominated by highly fire-sensitive palaeoendemics, organosols and Aboriginal cultural landscapes. At the same time as these values are threatened, a lack of burning threatens some fire-dependent vegetation types. We suggest an increase in planned burning of fire-tolerant and fire-requiring vegetation, maintenance of ignition suppression, an improvement in rapid response capability and an improvement in rapid detection of lightning fires is required in order to maintain many world heritage values

A review of wildland fire spread modelling, 1990-present 2: Empirical and quasi-empirical models

In recent years, advances in computational power and spatial data analysis (GIS, remote sensing, etc) have led to an increase in attempts to model the spread and behaviour of wildland fires across the landscape. This series of review papers endeavours to critically and comprehensively review all types of surface fire spread models developed since 1990. This paper reviews models of an empirical or quasi-empirical nature. These models are based solely on the statistical analysis of experimentally obtained data with or without some physical framework for the basis of the relations. Other papers in the series review models of a physical or quasi-physical nature, and mathematical analogues and simulation models. The main relations of empirical models are that of wind speed and fuel moisture content with rate of forward spread. Comparisons are made of the different functional relationships selected by various authors for these variables.Comment: 22 pages + 7 pages references + 2 pages tables + 2 pages figures. Submitted to International Journal of Wildland Fir

Fire models and methods to map fuel types: The role of remote sensing.

Understanding fire is essential to improving forest management strategies. More specifically, an accurate knowledge of the spatial distribution of fuels is critical when analyzing, modelling and predicting fire behaviour. First, we review the main concepts and terminology associated with forest fuels and a number of fuel type classifications. Second, we summarize the main techniques employed to map fuel types starting with the most traditional approaches, such as field work, aerial photo interpretation or ecological modelling. We pay special attention to more contemporary techniques, which involve the use of remote sensing systems. In general, remote sensing systems are low-priced, can be regularly updated and are less time-consuming than traditional methods, but they are still facing important limitations. Recent work has shown that the integration of different sources of information andmethods in a complementary way helps to overcome most of these limitations. Further research is encouraged to develop novel and enhanced remote sensing techniques