Study finds reforestation may lower the climate change mitigation potential of forests

May 28, 2010

Scientists at the University of Oklahoma and the Fudan University in Shanghai, China, have found that reforestation and afforestation -- the creation of new forests -- may lower the potential of forests for climate change lessening.

Yiqi Luo, professor of ecology in the OU College of Arts and Sciences Department of Botany and Microbiology, and Changzhang Liao, Bo Li and Changming Fang, professors of ecology in the Fudon University Department of Ecology and , examined whether plantations have the same ecosystem carbon stock as natural forests.

By synthesizing 86 experimental studies between plantations and their natural forest counterparts, Luo and colleagues found plantations substantially reduce carbon stock in ecosystems in comparison with natural forests.

"That decrease in ecosystem carbon stock should be accounted for, together with other forest products such as the harvested wood, when the total mitigation of reforestation is evaluated," said Luo.

This study challenges the idea that planting non-native or native-improved growth species on historical forest land yields greater carbon accumulations rates. They argue against the replacement of natural forests by reforestation, also known as plantations, to help stave off .

Plantations established on non-forested fields such as agricultural lands do help with the control of ; however, converting farmland to forests decreases the amount of carbon absorbed by the soil. Another form of gas, methane, also is affected by the conversion. Converted soil loses 80 percent of capability to degrade methane as compared to natural forests when it is developed as a plantation.

To minimize negative effects of plantation, appropriate management practices need to be adopted. Site preparation without burning, for example, leads to less loss than that with burning. To avoid ecosystem degradation associated with plantations, restoration measures need to be implemented to engineer ecosystems toward their natural potentials.

"The shifts from natural forests to plantations can also generate other ecological problems," writes Luo. "For example, soil bulk density, representing the degree of soil compaction, increases, possibly leading to limitation of rooting systems and destruction of soil structure in plantations. Additionally, plantations decrease stream flow.

"On the positive side, plantations can provide commodities for human needs (e.g., timbers). Therefore, we are now facing a great challenge of developing a management policy for plantation practice that minimizes their negative impacts on ecosystems but maximizes their commodity values."

Explore further: Pine Plantations May Be One Culprit in Increasing Carbon Dioxide Levels

More information: Findings from this research were recently published in the scientific journal PLoS One.

Related Stories

Forests' long-term potential for carbon offsetting

April 15, 2008

As well as cutting our fossil fuel emissions, planting new forests, or managing existing forests or agricultural land more effectively can capitalise on nature’s ability to act as a carbon sink. Research published online ...

Protecting natural forests crucial for climate change

August 6, 2008

(PhysOrg.com) -- South-east Australia’s natural forests are among the most carbon dense in the world and store three times more carbon than Australian and international climate change experts realise, a world-first study ...

Recommended for you

Ice sheets may be more resilient than thought

September 3, 2015

Sea level rise poses one of the biggest threats to human systems in a globally warming world, potentially causing trillions of dollars' worth of damages to flooded cities around the world. As surface temperatures rise, ice ...

Clues from ancient Maya reveal lasting impact on environment

September 3, 2015

Evidence from the tropical lowlands of Central America reveals how Maya activity more than 2,000 years ago not only contributed to the decline of their environment but continues to influence today's environmental conditions, ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

CarolinaScotsman
not rated yet May 29, 2010
So if we cut down a tree, we are harming the evironment and if we plant a tree, we are harming the environment. Sounds like a catch 22 to me.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.