The deadly pathogen known as sudden oak death is spreading throughout the Bay Area, infecting more trees in more places than have ever been seen before, according to scientists tracking the disease.

The Forest Pathology and Mycology Laboratory at UC Berkeley used 10,000 tree and plant samples collected by 500 citizens between April and June this year to document a dramatic increase in the infection rate from Napa to the Carmel Valley and virtually everywhere in between.

"We found that the number of positives were double and in some cases triple what they were last year," said Matteo Garbelotto, the UC Berkeley forest pathologist who organizes the annual surveys. "We were surprised. That was a big jump."

The findings are part of a major effort over the past four years to involve citizens in the battle against the mysterious pathogen, which has killed hundreds of thousands of oak trees from Big Sur to southern Oregon.

Arborists and ecologists are afraid that sudden oak death could eventually denude California’s golden hills of its signature tree. As it is, experts predict as many as 90 percent of California’s live oaks and black oaks could die from the disease within 25 years, reported the San Francisco Chronicle recently. To read the complete article, click here.