''Sci-fi'' forest to track effects of increasing CO2 levels

London

Scientists have developed a 'sci-fi' outdoor laboratory in the UK to find out how forests will respond to the levels of atmospheric carbon dioxide expected by the middle of the 21st century.

The industrial-scale experiment in a Staffordshire forest encircles trees with 25 metre masts gushing high levels of carbon dioxide (CO2).

The site is surrounded by a three metres anti-climb fence and silvery tubes snake along the forest floor.

The role of plants in taking up CO2 is one of the known unknowns in climatology.

Researchers believe that as levels of CO2 increase the trees will fix more of carbon into their trunks, roots and organic matter in the earth.

"We are confident that trees will continue to take in more CO2, though we are quite sure that there will be other things that will start to limit that," said Rob Mackenzie, from Birmingham University.

"Rising temperatures will also change the ability of plants to absorb CO2 — they are adapted to current temperatures," Mackenzie told the 'BBC News'.

Humans and forests currently participate in a mutually beneficial exchange in which trees are fed by increasing CO2, and the trees in turn lock up carbon that would otherwise remain in the atmosphere, heating the planet.

Trees are estimated to be storing between a quarter and a third of the carbon produced by burning fossil fuels, and the earth is becoming greener as a result.

 One of the great imponderables in climate science is how long forests will continue to buffer climate change as CO2 levels continue to increase. PTI