Shelterbelts - a tool for climate change

Trees have been used for more than a century to protect the farmstead and animals from vicious winter winds and to reduce the possibility of soil erosion. But another important advantage of tree plantings, such as shelterbelts, has only recently been recognized: trees clean the air.

By acting as filters, they remove dust and greenhouse gases (GHGs), such as carbon dioxide, from the atmosphere, replacing them with life-giving oxygen. By lowering carbon dioxide levels, trees may help reduce the effects of global climate change.

Studies performed at Agriculture and Agri-Food Canada's (AAFCs) Shelterbelt Centre illustrate how much carbon is fixed in prairie shelterbelts and the rate at which the carbon is accumulated. The Centre is administered under AAFCs Prairie Farm Rehabilitation Administration (PFRA).

"Results of our studies show that the above-ground portion of a mature poplar tree in a shelterbelt stores an average of 974 kg of carbon dioxide," said Bob Turnock, shelterbelt specialist with the Centre. "Green ash trees average 231 kg, white spruce average 523 kg, and caragana average 143 kg. These figures do not include the carbon stored in the roots, which may be equal to 50-75 per cent of the carbon stored above ground."

Further work by the Centre has focused on the rate at which carbon is accumulated in tree and shrub species. Poplar trees grow quickly and accumulate carbon at a faster rate. Slower growing species, such as spruce, accumulate carbon at a slower rate. However, slower growing trees live longer and therefore work as carbon sinks for longer periods of time. This information allows experts to predict the carbon contents of future shelterbelt plantings.

"The amount of carbon that can be held by shelterbelts can only be seen as a small part of the solution to the greenhouse gas problem," Turnock continued. "The main advantage of shelterbelts is that they increase energy efficiency and reduce heating bills by as much as 25 per cent by protecting buildings from winter winds. Also, wood can be used as a renewable fuel source for heating homes and buildings, replacing non-renewable fuels like oil and coal."

The Shelterbelt Centre works in partnership with industry to make Canada the world leader in food safety, environmental stewardship, research and innovation. The CCAF supports the goals of Agriculture and Agri-Food Canada's Agricultural Policy Framework (APF), which puts the necessary programs in place to bring long-term security and sustainability to Canada's agricultural sector.