Last winter John Brown’s favorite chanterelle patch died.
For years, the longtime member of the Fungus Federation of Santa Cruz had visited a particular cluster of live oak trees during walks in the woods just west of San Jose. Many mushrooms share a symbiotic relationship with particular tree species, and coastal chanterelles usually appear in the close presence of live oak and tanoak trees.
“These three or four trees produced a lot of mushrooms,” says Brown. “In a bad year, I’d get 15 or 20 pounds of chanterelles, and in a good year 25 or 30.”
But several years ago Brown noticed dry, dead and discolored spots appearing on the trees’ leaves—the signature mark of Phytophthora ramorum, a disease that has killed millions of oak and tanoak trees in California and earned the dire-sounding nickname “sudden oak death.” Over several years, Brown’s beloved oaks died and toppled over, and this season the soil around them produced, for the first time, no chanterelles at all.
Closer to home, the blight has affected, among other areas, the Soquel Demonstration Forest.
“While people have still found black trumpets there, many, many tanoaks have died,” says David Rust, a mushroom hunter who lives in the East Bay. “Places where we used to pick them in quantity are now lost.”
In Marin County, in particular, disaster is unfurling, and many mushroom hunters have reportedly all but given up on their old chanterelle haunts.
Phil Carpenter, the president of the Fungus Federation of Santa Cruz, has seen less impact locally than some regional mushroom hunters—a perhaps ironic fact, given that scientists have traced the pathogen to a Scotts Valley nursery. Carpenter often hunts in the Santa Cruz Mountains above 1,000 feet elevation where effects of the blight seem to have been less dramatic than nearer to sea level, he says. Alec Stefansky, another local hunter, says sudden oak death seems to be less severe in Santa Cruz County than in mushroom country farther south. But Stefansky, who owns and makes beer at Uncommon Brewers, collects wild candy cap mushrooms for use in his brewery’s Rubidus Red Ale. He hunts the fragrant, maple-scented mushrooms among live oaks and tanoaks and is concerned about how candy cap mushrooms will respond if their host trees perish.
Local researchers studying P. ramorum and the trees it attacks have discovered in live oaks some resistance to the disease, but the outlook for tanoaks may be grimmer. Matteo Garbelotto, a UC–Berkeley research scientist, says some tanoak populations have shown, at best, genetic “tolerance” to P. ramorum at a rate, he guesses, of 2 percent of trees.
“However, tolerance does not equate to survival, but maybe just longer survival,” Garbelotto said.
Few familiar with its power downplay the seriousness of sudden oak death. It first appeared in California in 1995 and is now present in at least 14 coastal counties between Big Sur and southwest Oregon. P. ramorum’s leafless, skeletal victims can be seen standing among the surrounding greenery in many places—like along Highway 17 and around Crystal Springs Reservoir from Highway 280—and just how badly the blight will affect mushrooms depends on how badly it impacts forests.
