If All The Trees Fall in the Forest

One scorching June day two years ago, plant pathologist David Rizzo paid a visit to China Camp State Park. China Camp is a sanctuary of rolling golden hills and dense oak forest that hugs the shores of San Pablo Bay, California. It's a popular spot for hikers and campers, with a gentle wildness that makes it seem much more than 20 miles from San Francisco. But Rizzo was there on a serious mission, hot on the trail of a mysterious disease that was destroying the park's prized coast live oaks. Local rangers had spent years tearing out foreign interlopers like eucalyptus to make room for native trees. Now their work was unraveling. Month by month, the majestic, gnarled oaks were dying. "It was like losing old friends," ranger Patrick Robards says. "I kept saying: 'What's happening to my old friends?'" Rizzo and three colleagues circled through one of the park's ...