Fires are, of course, a natural part of the Australian landscape. There are remnants of Gondwanic vegetation, especially in Tasmania, that are extremely fire sensitive, and fire should be excluded from these communities wherever possible. But fire is a regular feature of our mountain and foothill environments.
However, fire seasons are becoming longer and more extreme and this is impacting on mountain environments. From the huge fires in Tasmania over the 2018/ 19 summer to repeated wildfire in the Victorian Alps which is changing the nature of ecosystems, fire is increasingly impacting negatively on mountain ecosystems.
What does this summer look like in terms of fire risk in the mountains? The Australian Seasonal Bushfire Outlook August 2019 has just been released and points to a ‘highly active’ fire season.
The report shows that there is a ‘potential for a highly active season following a very warm and dry start to the year. The east coast of Queensland, New South Wales, Victoria and Tasmania, as well as parts of southern Western Australia and South Australia, face above normal fire potential. The Outlook draws on input from the Bureau of Meteorology and all Australian fire agencies to plan ahead for the fire season’.
The following is taken from the report:
The Australian Seasonal Bushfire Outlook: August 2019 shows fire potential across Australia over the coming months. Above normal bushfire potential refers to the ability of a large fire to take hold when you take into consideration the recent and predicted weather for a particular area, the dryness of the land and forests, recent fire history and local firefighting resources.
The Australia Seasonal Bushfire Outlook August 2019 is used by fire authorities to make strategic decisions on resource planning and prescribed fire management for the upcoming fire season.
The Outlook map shows the bushfire outlook for Australia through to the end of 2019. This map has been combined with the outlook for the northern Australia bushfire season, which was released in July, to show the areas of fire potential for all of Australia.
This Outlook will be reviewed towards the end of spring to take into account the impacts of actual temperatures and rainfall in the lead up to summer.
Here are some excerts relevant to mountain environments:
The ACT has received less than average rainfall over the last two years, leading to
a persistent and high level of drought. The lowland forests are dry, while highland
forests are relatively moist. This indicates that fuel flammability in the lowland forests
could remain high, creating risks early in the fire season.
The outlook indicates a potential for the highland forests to dry out, however this could be delayed by the occurrence of summer rain. Heatwaves and dust storms may make bushfire detection and suppression more challenging at times during the season.
The overall bushfire risk for the ACT is above normal.
Potential for above normal bushfire activity continues across the coastal and foothill forests of East Gippsland, extending into West Gippsland and the Great Dividing Range. These areas are now experiencing their third consecutive year of significant rainfall deficit, with severe levels of underlying dryness persisting in soils and heavy forest fuels, along with higher abundance of dead fuel components and higher flammability of live vegetation.
Across the rest of Victoria, mostly normal bushfire activity is expected.
There is uncertainty around the effect of the Indian Ocean Dipole and warm/ dry outlook, with some risk that ash forests in the central highlands may dry out at faster
rates and become more flammable than normal during summer.
For the early part of Tasmania’s fire season, most of the state has normal fire potential.
The western half of the state is wet, but the east is drier than normal and has above normal fire potential. Without significant rain in the coming months, this area will expand. As in recent years, increased fire activity is likely in this dry strip before December and will require considerable response efforts.
The fire season in the remainder of the state will commence more normally, in late
spring or early summer, and provide good conditions for planned burning.