Growing argument

Environment | The emergence of secondary rainforest in the Amazon has ignited a debate about the importance of old growth preservation | Mark Bergin

Zitha Olsen, Majbrit Hoyrup/©2007 MCT/Newscom

Rainforests are worth protecting. The dense jungles of vegetation cover only about 7 percent of the world's land surface but house, according to some estimates, about half of all plant and animal species.

So it was that a New York Times story last month questioning the importance of old-growth preservation set off a firestorm in the environmentalist community. A buzz of emails and breathless phone calls swirled between biologists from the Amazon to Southeast Asia.

The story quoted Smithsonian senior scientist Joe Wright, who believes that "secondary" forests emerging on the abandoned farmland of once agrarian societies can largely serve to replace the acreage of pristine forests lost each year to fire, logging, or palm oil extraction. That message is not a new one; Wright said as much two years ago. And the UN and Smithsonian Institution have recognized the environmental benefits of new growth since 2005.