Fire and carbon

FIRE and carbon are at the heart of forest management in Tasmania but are often misunderstood due to complex nature of eucalypt forests.

The way in which the two elements are linked is detailed in the Forestry Tasmania report Fire and Carbon in Managed and Unmanaged Forests.

Division of Forest Research and Development Chief Scientist Dr Steve Read said fire was the dominant controlling ecological force within eucalypt forests.

“Eucalypts have evolved with fire over millions of years, developing flammable oils and hanging strips of bark as well as adaptations to survive fire,” he said.

“This adaptation makes for efficient and effective sustainable timber harvesting. Many species can regenerate without replanting, and a complex and biologically diverse and resilient forest ecosystem can develop without further intervention.”

Dr Read said inadequate levels of fire could cause significant ecological changes and in managed native forests had been linked to forest health issues such as dieback and chronic decline of eucalypts.

Prescribed burns can have a patchy impact, with areas within burn boundaries often left unburnt.

“This can have beneficial ecological consequences as in general diverse landscapes are healthy and ecologically resilient,” Dr Read said.

“Variability across the landscape can also be achieved through a mix of coupes and unburnt reserves.”

Dr Read said managing solely for old-growth forest would not necessarily give the maximum reduction of atmospheric carbon.

“Old-growth forests have the lowest sequestration rate of any forest stage,” he said.

“Old-growth forests also have the largest emissions when they burn and do not offer the chance to accumulate wood products.”

Dr Read said the absence of smaller controlled fires could increase the risk of future large scale wildfires which release large amounts of carbon into the atmosphere. It is estimated that 150 million tonnes of carbon were added to the atmosphere in the 2003 and 2006/7 wildfires in Victoria, with similarly large amounts being released from wildfire annually in the United States.

“On the other hand management involving short-term carbon loss, such as thinning or fuel-reduction burning, can decrease the intensity of subsequent large fires and lead to smaller carbon emissions over the long-term,” Dr Read said.
 

To read the full Fire and Carbon in Managed and Unmanaged Forests report or to read a summary of the report see links below.

Download links to reports below:

1/ Fire and Carbon in Managed and Unmanaged Forests report [1,147 kb PDF]

2/ Report summary
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