Blight Imperils Western Pines

California's coastal ecosystem and aesthetics threatened by spreading fungus.

Hiking down a seaside trail beneath a canopy of pine, eucalyptus, and oak, Rick Hawley is a walking compendium of the natural beauty that thrives untouched on this stretch of virgin California coast.

The executive director of a local land trust known as Greenspace points out vultures that ride the updrafts above and herons that skim blue ocean below. But he looks concerned as he stops abruptly in front of a small pine tree.

Raking back the needles of a six-foot Monterey pine seedling, he reveals a canker in the bark about 12 inches from the tree top. Above it, needles are absent or brown and dry. "This is [the result of] a fungus that could wipe out the last remaining stands of native Monterey pine within a decade," says Mr. Hawley.

The words are as disturbing as the surroundings are beautiful, and the full import of the problem is only gradually dawning on ecologists and residents. Indeed, they say that this burgeoning plant condition is threatening not only the unique aesthetics and ecosystem of the California coast, but also a multibillion-dollar paper and pulp industry as far away as New Zealand.

First reported in 1986, the fungus known as pine pitch canker has now spread to 17 coastal and inland counties stretching from San Diego to Mendocino. That range includes the only three remaining, native stands of Monterey pine in the world. The problem is easily visible to anyone as intermittent sections of browned-out tree tops leave a splotchy appearance to forested hillsides up and down the coastal foothills.

Besides the Monterey pine, with highly-veined branch structures that produce its distinctive, soft-splayed canopy, the fungus threatens 10 other species of native California pine - from Ponderosa and to Douglas fir. If not stopped (researchers have not yet found a cure) the fungus could mean the near-complete elimination of the Monterey pine.

In addition to potentially lowering the property values of toney estates along the central coast, such a demise would also raise concerns about whether the blight will effect other strands of the pine.

In a hybridized, ornamental form - grown in nurseries and planted along highways and front yards - there are millions of Monterey pines from San Francisco, through the massive Central Valley to Los Angeles and further south.

This hybrid form is desirable because it is one of the fastest-growing pine trees in the world, making it a leading tree for lumber.

"We are very concerned that this ... not get established in New Zealand as it has in California," says John Bain, staff entomologist at the New Zealand Forest Research Institute in Rotorua. Noting that New Zealand's commercial forest industry relies 90 percent on the Monterey Pine for its multibillion-dollar lumber and paper industry, Mr. Bain says, "Such a spread here would be absolute disaster for this industry."

Part of the problem, say Bain and others, is the speed with which the fungus can spread. Native insects, including a wide variety of tree-boring beetles, can carry it.

"What is more disconcerting is that [pine pitch canker] is seed-borne and now shown to be soil-borne," adds David Wood, a professor of forest entomology at the University of California, Berkeley.

To further study the problem and raise public awareness of it, a Pine Pitch Canker Task Force was formed in 1994 through the California Forest Pest Council. "The current emphasis is on preventing its spread," says Hawley, a task force cofounders. "The loss of this pine tree here would be to remove one of North America's greatest gifts to the world."

You've read  of  free articles. Subscribe to continue.