833. Monterey Pine Pitch Canker

It’s hard to imagine Asilomar without the majestic Monterey pine. This fast-growing tree can grow up to 100 feet tall. Its few original native locations are near Santa Cruz, in the Monterey area and Cambria. But the poor health of the pines is making it more susceptible to pests and disease and is endangering its survival. Retired State Park Environmental Scientist Lorrie Madison. MADISON: Since 1992 at Asilomar we’ve been under attack by a disease called pine pitch canker. NARRATOR: The disease is caused by a fungus spread by insects such as bark beetles. It likely came to the Monterey Peninsula in a load of infected firewood, and spread rapidly through the pine forest. Open wounds from pruning can also be a welcome entry point for airborne fungal spores. Nearly all of Asilomar’s pines now show signs of infection. MADISON: As you look through the grounds and you look through the canopies of the trees you’ll notice that we have what’s called flagging. It’s a lot of dead twigs and branches just sort of hanging there, and brown. NARRATOR: You’ll also notice trees with gashes oozing with pitch. This is another sign of the disease. Luckily, there is some hope for the pines. There is no cure for pine pitch canker. Fungicides could kill the fungus, but would also kill the organisms vital to a healthy ecosystem. In 2002, Asilomar ecologists began an innovative tree inoculation program. They based their work on techniques developed by researchers at the University of California at Davis. The program depends on the small percentage of uninfected native pines. Retired State Park Environmental Scientist Lorrie Madison. MADISON: We find trees that seem to have some resistance to the disease. We collect the cones and we extract the seeds, usually by nuking them in a microwave from two to three minutes. We grow thousands and thousands of seedlings from these semi-resistant Monterey pines. When they’re about a year old we start inoculating them with the fungus that causes the disease. NARRATOR: After a month, park staff measures the lesion at the point of infection on the inoculated seedlings. If the lesion measures less than 15 millimeters, the tree will most likely remain resistant to the fungus. MADISON: There’s also new research out that shows that with repeated exposure to the fungus the tree can develop systemic resistance. It’s a very slow process but very worthwhile, because it maintains the genetic integrity of our stands and I think it’s the best shot we have at dealing with the situation.