ScienceDaily has an excellent overview of Sudden Oak Death, which is a nasty, vicious disease that can knock out wide stretches of forest. It sort of challenges the assumption that getting people into the woods will encourage them to protect it. While the theory sounds like a fine rationalization for playing in the outdoors, there’s this reality:

“There is some compelling evidence that humans could be moving the disease in infested soil,” Meentemeyer said. “We have found evidence for human involvement at three different scales of analysis. First of all, the pathogen is much more likely to occur along hiking and biking trails, where humans travel. Second, using some of our landscape and regional data, we have shown that highly visited state and county parks have more disease than private ranches and lands that have very limited visitation.

The good news is that only 10 percent of California’s forests have been affected; the bad news is: 90 percent are potential targets of the pathogen.

Local angle: If you go to the Monte Bello Open Space Preserve, you’ll notice these wire-brush contraptions at the trailhead. The weren’t put there to help you get the mud out of your pricey hiking boots: they’re there to slow the spread of sudden-oak death. If you see ’em, use ’em.