News from the world of Trees

American Forests, Autumn, 1999

FUNGUS THREATENS PINES WORLDWIDE

Californians have always admired the Monterey pines that tower over their coasts and hillsides. Now a deadly fungus threatens to eradicate them from their native range.

No one knows how pitch canker, a fungal disease native to the Southeast and Mexico, arrived in California. But since its discovery in 1986 in Santa Cruz and Alameda counties, the disease has spread to at least 15 coastal and nearby inland communities. Today, the only three remaining pure stands of native Monterey pine (Pinus radiata) are infected, and foresters say other species could be at risk.

"We don't have any cure for it," says Don Owen, co-chair of the Pine Pitch Canker Task Force. "And the ultimate effects are unknown. Whether it will cause a great deal of damage to other trees simply hasn't been seen yet."

Monterey pine is by far the most susceptible, with some areas showing infection rates between 80 and 90 percent, Owen says. That could spell disaster for the species the world over, which depend upon California's native Monterey pine stands for their genetic purity, says Dave Adams, a pitch canker expert from the California Department of Forestry and Fire Protection.

"The native Monterey pine is the genetic resource for all radiata pine around the world," Adams says. "The fungus could have a tremendous effect commercially because people in those countries would like to renew their genetic stock and they can't."

Landowners should look for wilting and fading needles and resin oozing from infection sites. Another problem: bark beetles and other insects that "team up" with the fungus to spread the disease to other trees.

If not for the beetles "the disease would probably not have much of an impact on these pines. It's a happy thing for the fungus and not a happy thing for the trees-- and the bugs probably don't really care much one way or the other," Adams says. "But when the trees start disappearing, they will."

Editor's note: If you live outside an infected area and think your tree has pitch canker, contact your county agricultural commissioner's office or the California Department of Forestry and Fire Prevention (530/753-3448).

A HISTORIC SAVE

On a fall afternoon in 1997, Jeff Meyer, project director for AMERICAN FORESTS' Famous & Historic Trees, gathered red, ripe magnolia (Magnolia grandiflora) seeds from a towering tree at The Hermitage in Tennessee. The tree had been standing guard over the final resting place of seventh president Andrew Jackson for more than 150 years.

The seeds Meyer collected that day at the Hermitage and from tulip poplars (Liriodendron tulipfera) next door at Jackson's nephew's estate would be used to grow offspring for the Famous & Historic Trees' Presidents collection.

Six months later, the stately magnolia was gone, the victim--along with more than 1,200 other of The Hermitage's trees--of a tornado that hit the Nashville area on April 16, 1998. Many of the downed trees were historically significant: In addition to the magnolia, the destroyed trees included cedars that had lined the driveway since Jackson's days, a beech estimated at more than 300 years old, and Tennessee's largest tulip poplar, later determined to be 275 years old.