Monday, May 03, 2010

Quantification of global gross forest cover loss

The study — titled "Quantification of global gross forest cover loss" by Profs. Matthew Hansen and Peter Potapov of the Geographic Information Science Center of Excellence at the South Dakota State University — was posted last week on the Proceedings of the National Academy of Sciences Web site. USA Today covered the story:
Out of seven of the most heavily forested nations on Earth, the United States experienced a greater percentage of forest loss from 2000 to 2005 than did any of the other countries, a study said Monday.

The United States lost more than 46,000 square miles of forest in those years, a size roughly equivalent to the state of Pennsylvania. That's about 6% of the nation's forested land.

"That's the most of the seven countries that have over 1 million square kilometers of forest," says study lead author Matthew Hansen of South Dakota State University.

Worldwide, researchers determined that the globe lost forest cover of nearly 400,000 square miles — roughly 3% of the world's forested areas — during the first half of the last decade. The other countries in the study were Canada, Russia, China, Brazil, Indonesia and the Democratic Republic of the Congo.

The study found that the forest loss was the result of both human and natural causes.

"We do not quantify what the causes are, and we do not quantify how much forest gain there was from 2000 to 2005," Hansen says. "But clearly, industrial harvesting/clearing is very important."

Man-made causes of forest loss include logging and wildfires caused by people. Natural causes would include natural wildfires and storm damage.

The one part of the contiguous USA that experienced the most forest loss was the Southeast, a large chunk of which lost more than 10% of its forest cover from 2000 to 2005, the year for which the most recent data were available.

Hansen points out that the forest loss in the USA isn't necessarily permanent: "This does not mean that (the forests) do not regenerate, and we make no statements whatsoever about sustainability," he says. "But, compared to other regions of the world, a lot is going on."

The first of its kind, the study used satellite images to measure forest loss around the world. Hansen says much more study in the area is needed as improvements are made in satellite technology and accessibility. "We need to be more ambitious," he says. "If we had an improved monitoring capability, you could imagine a daily 'land report,' akin to weather, where fires, floods, crop emergence, new forest clearing, new construction are quantified."

Some of those who left comments online did not agree with the research results:

From smc8660:
As a forester in the southeast, it saddens me to see this article. By only covering the LOSSES they are crying wolf. Here in the Southeast, we supply most our country's timber but as any good forester knows our pine plantations are crops. Just like you would do with corn, we replant our trees. Usually, we replant in the same year that we harvest. Pine in the SE can be fully mature and ready for harvest, under good management at 25 years. If it is for pulpwood (paper products) it can be ready in 15 years.

So yes, you will see truck after truck of mature pine being taken to a mill. What you never see is the truck containing thousands of seedlings. Big trees are easy to see, the thousands that arrive in refrigerated trucks are not.

Think about it, would it make ANY sense to ignore replanting? We wouldn't have a career if we didn't replant. Plus, I guarantee, most people cannot tell the difference between 20 yr old pine and 40 year old pine. In the SE, "old growth" (a misleading term at BEST) is 50-70 yrs.

Support agriculture, support your land-grant universities, support your future with responsible forestry.

Please be a more balanced reporter Mr. Rice, it would improve your reputation.


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