Reviving American chestnuts may mitigate climate change

Jun 10, 2009
Reviving American chestnuts may mitigate climate change
Douglass Jacobs examines a young hybrid of the American chestnut. He expects the trees could be reintroduced in the next decade. Credit: Purdue University file photo/Nicole Jacobs

A Purdue University study shows that introducing a new hybrid of the American chestnut tree would not only bring back the all-but-extinct species, but also put a dent in the amount of carbon in the Earth's atmosphere.

Douglass Jacobs, an associate professor of forestry and natural resources, found that American chestnuts grow much faster and larger than other hardwood species, allowing them to sequester more than other trees over the same period. And since American chestnut trees are more often used for high-quality hardwood products such as furniture, they hold the carbon longer than wood used for paper or other low-grade materials.

"Maintaining or increasing forest cover has been identified as an important way to slow climate change," said Jacobs, whose paper was published in the June issue of the journal Forest Ecology and Management. "The American chestnut is an incredibly fast-growing tree. Generally the faster a tree grows, the more carbon it is able to sequester. And when these trees are harvested and processed, the carbon can be stored in the hardwood products for decades, maybe longer."

At the beginning of the last century, the chestnut blight, caused by a fungus, rapidly spread throughout the American chestnut's natural range, which extended from southern New England and New York southwest to Alabama. About 50 years ago, the species was nearly gone.

New efforts to hybridize remaining American chestnuts with blight-resistant Chinese chestnuts have resulted in a species that is about 94 percent American chestnut with the protection found in the Chinese species. Jacobs said those new trees could be ready to plant in the next decade, either in existing forests or former agricultural fields that are being returned to forested land.

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

Jacobs studied four sites in southwestern Wisconsin that were unaffected by the blight because they are so far from the tree's natural range. He compared the American chestnut directly against black walnut and northern red oak at several different ages, and also cross-referenced his results to other studies using quaking aspen, red pine and white pine in the same region.

In each case the American chestnut grew faster, having as much as three times more aboveground biomass than other species at the same point of development. American chestnut also sequestered more carbon than all the others. The only exception was black walnut on one site, but the American chestnut absorbed more carbon on the other study sites.

"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," Jacobs said.

Jacobs said trees absorb about one-sixth of the carbon emitted globally each year. Increasing the amount that can be absorbed annually could make a considerable difference in slowing , he said.

"This is not the only answer," Jacobs said. "We need to rely less on fossil fuels and develop alternate forms of energy, but increasing the number of American chestnuts, which store more carbon, can help slow the release of carbon into the atmosphere."

Carbon dioxide is considered a major greenhouse gas, responsible for rising global temperatures.

Jacobs said that since this study looked at aboveground carbon sequestration, future studies would seek to understand more about how forests that contain American chestnuts store carbon below the ground. The Stry Foundation, Electric Power Research Institute, and Hardwood Tree Improvement and Regeneration Center funded the research.

Source: Purdue University (news : web)

Explore further: Rising sea levels to cost Australia billions, study says

add to favorites email to friend print save as pdf

Related Stories

Blight-resistant American chestnut trees nearing reality

Dec 05, 2008

(PhysOrg.com) -- The demise of the American chestnut is one of the great ecological disasters of our time, according to a chestnut expert in Penn State's College of Agricultural Sciences, who envisions a day ...

Seeing The Forest And The Trees

Oct 24, 2005

With human emissions of carbon dioxide on the rise, there is growing interest in maintaining the Earth's natural mechanisms that absorb and store carbon.

Recommended for you

Dutch unveil big plan to fight rising tides

9 hours ago

The Netherlands on Tuesday unveiled a multi-billion-euro, multi-decade plan to counter the biggest environmental threat to the low-lying European nation: surging seawater caused by global climate change.

Drought hits Brazil coffee harvest

11 hours ago

Coffee output in Brazil, the world's chief exporter, will slide this year after the worst drought in decades, agricultural agency Conab said Tuesday.

Landmark fracking study finds no water pollution

13 hours ago

The final report from a landmark federal study on hydraulic fracturing, or fracking, has found no evidence that chemicals or brine water from the gas drilling process moved upward to contaminate drinking water at one site ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

zevkirsh
4.3 / 5 (3) Jun 11, 2009
this headline alone is pure evidence of the problems of science research tagging itself onto a big money progress initiative/hotbutton issue. i dont even need to read the article to know that whatever it says is altered beyond recognition to be representative of the true nature of the inquiry behind the 'official' scientific questions answered in this published result.
Birger
3.3 / 5 (3) Jun 11, 2009
Actually, restoring an almost iconic tree that now is near extinction seems enough of an argument for me, and never mind carbon storage.

The North American environment has already been impoverished beyond recognition, first by the extinction of the ice-age megafauna and then by the almost-extinction of the buffalo and establishment of agricultural monocultures on their former grazing grounds. There are many other recent extinctions as well. We can (probably) not clone back the extinct pigeons that were so typical for North America just a century ago, but we can easily plant chestnut hybrids.
mongander
not rated yet Jun 12, 2009
Science is now all about massaging the data to fit your prejudice.