Saving the forest by cutting down trees

Dec 18, 2009

It's heart wrenching, but forest researchers have found that cutting down bay laurel trees can make a woodland a healthier environment for beloved oaks. The bay laurel trees are carriers of the pathogen Phytophthora ramorum. If the bacteria spreads to oaks, it causes a disease called Sudden Oak Death.

Lisa Kreiger of the San Jose Mercury-News reported that "emergency surgery" is taking place in the Santa Cruz Mountains to extricate bay laurels and give ancient and majestic native California oaks a better chance at survival.

UC Berkeley Cooperative Extension forest pathologist Matteo Garbelotto has observed that removal of bay laurels in a 10- to 20-yard radius of an oak doesn't eliminate the pathogen, but lowers its presence — so a potentially heavy attack is turned into a moderate one, the story said.

"These moderate attacks are less likely to result in an oak infection," Garbelotto was quoted in the article, which also appeared in the Monterey Herald and the Oroville Mercury Register.

Thinning the forest is expected to stem the spread of Sudden Oak Death, but it won't stop it. Although the vast majority of infections come from adjacent trees, the scientists say spores can also travel long distances by wind or creek or by dirt on hiking boots.

Nevertheless, UC Davis forest pathologist David Rizzo told the reporter he believes removing bay laurels is "a great idea."

"There are relatively few management options for the disease in wildland areas," Rizzo was quoted. "Stand manipulation is the primary tool we have."

UC Cooperative Extension offers extensive information on Sudden Oak Death. For articles, pictures and links, see the Sudden Oak Death media kit.


By Jeannette E. Warnert
Author - Communications Specialist

Attached Images:

California bay laurel leaves and flowers.