Carbon cycles
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Maintenance of forest contribution to global carbon cycles has been identified as one of the key criteria for sustainable forest management in Australia. Forests play an essential role in regulating the Earth’s atmosphere and are responsible for recycling the planet’s finite supply of water, carbon, nitrogen, and other essential elements.
Like all green plants, trees absorb carbon dioxide from the air and convert it into carbon in plant matter through a process called photosynthesis. Some of this carbon is kept within the plant as long as it lives, but when the tree decomposes or is burnt, the carbon is released back into the air in the form of carbon dioxide.
Growing forests act as natural ‘carbon sinks’, helping to remove carbon dioxide emissions from the atmosphere. Forest managers play an important role in monitoring global carbon cycles by estimating the amount of carbon stored in forests and forest products in Australia. This information is then used in the Australian Government’s National Carbon Accounting System which tracks greenhouse gas emissions and levels of carbon sequestration.
Case study – How long does it last? Carbon storage in wood products
on landfill
Photo: Forests NSW Image
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Since 2000, Forests NSW researchers, in collaboration with the National Cooperative Research Centre for Carbon Accounting, have been working to determine how long carbon remains stored in wood products.
It is estimated that some 4.5 million tonnes of wood and paper products go into Australian landfills each year. Internationally it is assumed that 20 to 25 per cent of the total weight of these products is released as the greenhouse gases methane and carbon dioxide. On that assumption, 1.5 per cent of Australia’s greenhouse gas emissions have been estimated to come from the decomposition of paper and wood products.
The researchers set about digging up old rubbish tips, recovering wood and paper products that had been buried for 46 years and analysing the products in a laboratory to test the decomposition assumptions. Their work showed that Australia’s greenhouse gas emissions from paper and wood products are lower than previously thought and demonstrated that timber is a greenhouse-friendly product.
For more information about carbon storage read the Bush telegraph magazine on NSW Department of Primary Industries website.
