SAN FRANCISCO

Sudden Oak Death Cases 'Worse Than Expected' In Bay Area

10/03/2011 02:49 pm ET | Updated Dec 03, 2011

Scientists tracking the prevalence of sudden oak death, a fatal pathogen that plagues tree populations in Northern California, have confirmed that the disease is at "near epidemic levels," the San Francisco Chronicle reported Sunday.

"We found that the number of positives were double and in some cases triple what they were last year," Matteo Garbelotto, a UC Berkeley forest pathologist who studies the prevalence of sudden oak death, told the Chronicle. "We were surprised. That was a big jump."

Garbelotto works with the UC Berkeley Forest Pathology and Mycology Laboratory along with hundreds of volunteers to track the disease. This spring, his team collected more than 10,000 samples from tree species throughout the Bay Area and found the infection to be rampant. In certain areas of the South Bay, a whopping 97 percent of examined samples tested positive for the poison.

First discovered in Mill Valley in 1995, sudden oak death (also known as phytophthora ramorum) has claimed the lives of thousands of oak trees along the northwest coast, from as far south as Carmel Valley and as far north as southern Oregon. And it seems poised to keep expanding: The Oregon Department of Forestry recently came across infected trees six miles north of the supposed quarantine zone.

According to the California Oak Mortality Task Force, the disease poses a major threat to the ecosystems it affects, creating the potential to completely destroy the way a forest functions. Wildlife lose food sources, fire patterns are altered and water quality decreases. Sudden oak death has nearly wiped out oak tree populations in parts of Big Sur, China Camp State Park and other nearby natural retreats.

And it shows no signs of retreating. In fact, Garbelotto said the most surprising results of his study revealed the disease spreading beyond the forests and into residential areas in the East Bay, including parts of North Berkeley, Oakland's Montclair district and San Leandro. "I didn't expect it to be that widespread," he told the Chronicle.

Luckily, one local treasure appears to remain untainted--for now. Not a single new infection was found in San Francisco's Presidio. "It's the only good news we got this year," Garbelotto said.

Learn more about how you can help contain and treat sudden oak death here, or check out the informational video below.

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