Watching the bush recover after fires
Watching the bush recover after fires by Sarina Locke Canberra, ACT 19/03/2009.
Just two weeks after the devastating bushfires in Victoria, green shoots of life were poking through the soil. A team of US ecologists have toured the Kinglake and Marysville forest areas to assess the ecological damage and water quality problems. With them was the senior forest ecologist in the ACT. Dr Margaret Kitchin, with Parks Conservation and Land, was impressed with their speed in assessing the damage, saying such a rapid response is a first for Australia.
The Burned Area Emergency Response team is a group of ecologists from a number of US Federal Government agencies, including the National Parks, Natural Resources Conservation Services, the USDA Forest Services and the Bureau of Land Management. Their website lists them as professional hydrologists, soil scientists, engineers, biologists, silviculturists, range conservationists, archaeologists.
“BAER is ‘first aid’ – immediate stabilisation that often begins even before a fire is fully contained. BAER does not seek to replace what is damaged by fire, but to reduce further damage due to the land being temporarily exposed in a fragile condition,” it says on the US National Parks Service website.
They’ve been doing this for many years in the US, but this is the first time such a rapid scientific assessment has been made, even as the fire was burning in Australian conditions. The fire, in February 2009, burnt 250,000 hectares in Victoria, and this BAER team took just seven days to assess the ecology and water in 100,000 hectares of it. Dr Margaret Kitchin says it’s been great training for her, in preparing for ecological responses to another fire around Canberra. They worked on the western flank of the fire ground to look at ‘potential threats that unstable soils, unstable areas or immediate threats to those (ecological) communities or species. She says what was really refreshing, that just two weeks after the fires, “there was already 10 cm of growth on some of the xanthoreas, …..or grass trees.”
The fauna specialists looked at the threatened species, like the Leadbeater’s possum, with the local Department of Sustainability and Environment; and also two types of owl and fish; the Macquarie Perch; and the bard galaxia. They replaced the nesting box for a lonely Leadbeater’s possum that had survived the fires.
She says that demonstrates the benefit of speedy assessment. But what if that possum’s tree is targeted for salvage logging? She says they assessed an area of 3,000 hectares of mountain and alpine ash that can be logged over the next two years. She says most of the area is protected by National Park, and included riparian areas. Dr Kitchin says the mountain and alpine ash are unique gum trees – fire can kill the tree, they don’t produce epicormic growth and they must grow from seed. But the forest can’t sustain another hot fire too soon, or its survival will be threatened.
Dr David Lindenmeyer, from the Australian National University’s Fenner school of Environment and Society says they can take 20 years without another major fire to mature enough to recover as a viable forest, and produce seeds. Andrew Campbell, a natural resource management (NRM) consultant with Double Helix, wrote in a recent essay, mountain and alpine ash, “are difficult to ignite (because they are usually wet forests with predominantly smooth bark), but when the conditions are right, they burn ferociously, creating an ash bed suitable for their regenerating seedlings.” “As ash seedlings are shade-intolerant, they regenerate best after very hot fires that destroy the canopy,” he writes. “In the absence of such fires over their life cycle, they will not persist. “When fires are exploding through the canopies of 200 plus feet high trees with volatilised oils creating a superheated vapour, the ground layer becomes virtually irrelevant. “Witnesses described huge trees literally exploding,” he writes.