California's redwood trees under attack by "burl poachers"

California's redwood trees are a national treasure, but the 1,000-year-old trees have had huge gouges hacked into their trunks. It's the work of what are being called "burl poachers," CBS News correspondent John Blackstone reports. They cut away the knobs that grow on the side of the trees and can be used to make furniture.

Since 2012, the attacks have damaged 25 trees in Redwood National and State Parks, some 300 miles north of San Francisco.

A statement from the park said, "Investigations are indicating that the black market for these materials is an income source for drug users and those with criminal histories."

"It is shocking," park ranger Mia Monroe said. "It makes me feel outraged that anyone would choose to hurt these trees."

Monroe works among the redwoods in Muir Woods National Monument near San Francisco. She said the burls are essential for reproduction. New trees grow from the old.

But burl, however, can be valuable as well to furniture makers.

Jim Parodi, owner of Artisan Burlwood in Berkeley, California, has been making furniture from burl for 35 years. His one-of-a-kind pieces sell for thousands of dollars. He said he knows the source of all the wood he buys.

"We source the wood really smartly, and we only use dead, fallen wood or low down or root rot or condemned," Parodi said.

To battle the burl poachers, park officials have closed a road through the trees at night and they have increased patrols and surveillance. The poachers, they say, are much like those who kill elephants to take their tusks.