• by Katie Mattern (washington)
• Tuesday, June 16, 2009
• Inter Press Service

Reducing carbon levels in the atmosphere may be as simple as planting a new breed of hybridised chestnut trees, according to a new study by Purdue University Associate Professor Douglass Jacobs.

The hybrid American chestnut tree, which is mixed with a similar and more disease-resistant Chinese chestnut tree, has been found to grow faster than other chestnut trees and retain carbon for a longer period of time, including after its death.

The American chestnut has been facing extinction since the chestnut blight was introduced in the early 1900s, according to Jacobs. But scientists previously had little incentive to bring it back because of its susceptibility to disease.

The decline of the tree has coincided with the rapid rise in the use of electricity and fuel-based transport that made the U.S. carbon output skyrocket in the twentieth century, contributing to the U.S.’s longtime top slot among carbon emitters.

However, the new hope for mitigating climate change is not ready to be planted in forests across the country just yet.

'We're really quite close to having a blight-resistant hybrid that can be reintroduced into eastern forests,' Jacobs said in a press release from Purdue. 'But because the American chestnut has been absent from our forests for so long now, we really don't know much about the species at all.'

A fungus that nearly made the trees extinct 50 years ago affected chestnuts from the northeastern U.S. all the way to southern states like Alabama.

However, the new trees, which will hopefully withstand another similar disease, are not going to be ready to plant across the U.S. for another decade. Jacobs and his team plan to plant the trees in forests or former agricultural fields that are being transformed into forested land.

Jacobs studied a population of remaining American chestnuts across southwestern Wisconsin and compared them to other varieties of chestnut trees. These trees were unaffected by the fungus because of their distance from the rest of their species.

He used these surviving trees and compared them to the growth rates of black walnut and northern red oak trees. Jacobs also looked at the results of similar studies of quaking aspen, red pine and white pine trees that were completed in the same region.

In his comparisons, Jacobs found that the American chestnut trees grew faster than all of the other types, and they had as much as three times more aboveground biomass than other species.

'Each tree has about the same percentage of its biomass made up of carbon, but the fact that the American chestnut grows faster and larger means it stores more carbon in a shorter amount of time,' he said.

The American chestnuts he studied also appropriated more carbon than any of the other trees in all but one of the study sites.

'[T]rees absorb about one-sixth of the carbon emitted globally each year,' said a Purdue press release announcing the results of the study.

Jacobs said that if the amount of carbon that is absorbed is increased, a difference can be made in slowing climate change and that these trees can greatly contribute to this effort.

'We need to rely less on fossil fuels and develop alternate forms of energy,' he said.

But even though these new hybrid trees are not going to be able to play a large role in reducing carbon emissions yet, the rest of the world is trying to develop alternate methods while Jacobs’s research is continued.

'We will begin looking at below ground carbon sequestration and how chestnut does on other site types,' he said. 'Hopefully this research will promote planting of chestnut (and other tree species) in the future, which will decrease carbon levels.'

Industrialised countries need to cut greenhouse gas emissions, including carbon dioxide, at least 40 percent by 2020 relative to 1990 levels for a reasonable chance of avoiding climate change.

The U.S. has been accused of holding back recent climate negotiations, especially during the United Nations climate talks that were held in Bonn and ended on Jun. 12.

The U.S. is also the world’s largest historical greenhouse gas polluter, according to Friends of the Earth Malaysia’s honorary secretary Meena Raman after the talks.

'The election of President (Barack) Obama created tremendous hope worldwide that the U.S. would finally play a leadership role in solving the climate crisis that - more than any other nation on earth - it is responsible for causing,' said Karen Orenstein of Friends of the Earth U.S.

'Unfortunately for the survival of people and the planet, the Obama administration's position at these U.N. negotiations sounds frighteningly similar to that of (former U.S. president) George Bush,' she said.

The U.S. administration is still talking about cutting U.S. greenhouse gas emissions only back to 1990 levels by 2020, rather than any actual reduction. However, under Obama’s targets, reductions would then reach 80 percent below 1990 levels by 2050.

Trials are being conducted in other states to see how they are affected now, according to Jacobs, and he believes that they will produce the same results as what they found in Wisconsin.

His findings were released in the June edition of the journal Forest and Ecology Management.

© Inter Press Service (2009) — All Rights Reserved. Original source: Inter Press Service

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