AUSTRALIA – A Victorian dairy farmer fears a peat fire still smouldering on his property from last month’s St Patrick’s Day fires will render large parts of land unusable.
Will Scott and his wife Lee, who have 300 cows on their 280 hectares at Cobrico in the state’s south west, believe up to 70 hectares of their still smouldering land had been significantly altered.
The farm has been in the family for decades.
“It’s burnt a metre or so deep down so we’re not sure we’ll be able to use that again,” Mr Scott said.
“Usually we have 250 young stock or dry cattle down on the flats but obviously they can’t go down there when it’s on fire.”
Peat forms when partially decayed organic matter accumulates underground over hundreds or thousands of years and its high carbon content means once it catches fire, it smoulders and is difficult to extinguish.
‘We can’t rebuild … it’s still burning’
Fire spread into the peat on the Scotts’ farm in the days after initial blazes began on March 17, and while emergency services tackle the fire daily, it could be months before they put it out.
Mrs Scott told ABC Radio said she believed the organic matter had been burnt out of the peat and all that was left was ash.
She said they would have to consider down-sizing or selling up if they could not use the land again.
“We’re not alone — there’s plenty of other people suffering — but we can’t rebuild our fence or redo our troughs because it’s just still burning,” she said.
“We can’t see when we can bring our kids home. It doesn’t seem very fair at the moment.”
The couple has two children aged nine and 11, and the family has been staying in Cobden at night since the fires started due to health concerns.
High carbon monoxide levels in smoke emanating from the fires have prompted an Environment Protection Authority warning and people exposed to the smoke have been advised to get regular health checks.
Burning peat ‘radically’ alters soil structure
University of Tasmania fire scientist professor David Bowman said the Scotts’ fears about the soil on their property being unusable were well founded.
“What happens with these underground peat fires is that the actual soil is being consumed and you’re going to lose volume of soil,” he said.
“So the soil surface will drop down, the water table will change and the nutrients in the soil are going to be turned into ash so they’re likely to be eroded off.
“It’s basically an unusual situation for farming in Australia where usually you worry about soil erosion but this is like instantaneous soil erosion by fire. It’s bad.”
Mr Bowman said peat soils accumulated over time in swamps through the partial decomposition of woody vegetation.
“When you drain them you can use peat soils for agriculture to grow grass and so on, but the danger is if they dry right out they’re very combustible because the primary component of the soil is carbon,” he said.
Mr Bowman said climate change and land management were likely to have contributed to the peat being so dry.
“Before settlement, Aboriginal people were living in that country for tens of thousands of years and they used fire a lot and they targeted wetlands for food resources,” he said.
“It does point out how strange these fires are relative to the environmental history of the lakes. In other words, they’ve been able to withstand drought cycles and lots of ignitions over time.”