Water

Wetlands soaking up carbon

By Country News

Victoria’s inland wetlands lock away the annual emissions of 185000 people, or roughly the population of Geelong, according to the state’s first-ever tally of these environmental resources.

The tally, which came to three million tonnes of carbon dioxide each year, was gathered by researchers from the Deakin School of Life and Environmental Sciences Blue Carbon Lab, and will increase understanding of how the environment helps to regulate greenhouse gas emissions.

Lead researcher Paul Carnell said inland or non-tidal wetlands were an integral part of Australia’s carbon budget.

‘‘While a lot more is known about how trees suck up and store carbon, freshwater wetlands can actually isolate 20 to 40 times more carbon than forests on dry land,’’ Dr Carnell said.

‘‘In their soil is a mixture of plant material and sediment from upstream or dryland areas.

‘‘Because these wetlands are anoxic (contain little oxygen), it’s hard for the carbon in this material to be broken down and re-released into the atmosphere.

‘‘Instead the carbon in this material is stored in the ground ... and each year new material is added to the wetlands’ overall carbon store.

‘‘It’s the reverse process of digging up and burning coal or oil; here wetlands are taking that gas and putting it back into the ground.’’

Victoria has about 530000ha of inland wetlands, which include marshes, peatlands, pools and lakes, making up about 2.33 per cent of the state’s land area.