Four years ago I was pushing a jogging stroller through the muddy mists of Mount Sutro when the area's usual tangle of ivy, blackberry, and eucalyptus branches opened up into an ancient trail where brush had been mysteriously hacked and dug away. Every week or so hence, I'd discover even more yards of newly manicured trail, freeing up for exploration an ever-greater portion of this 61-acre urban forest on the hill south of UCSF Medical Center. One Saturday morning, I encountered two fellows who were surprised I was pushing my daughters through their then-little-known trail work.
"What are you doing here?" one asked.
To which I responded: "What have you been doing here?"
My new acquaintance was Craig Dawson, a founder of volunteer group Mount Sutro Stewards. With picks, hoes, and shovels, the group has been restoring ancient footpaths that traverse the dense stands of Tasmanian blue gum eucalyptus planted by then-San Francisco Mayor Adolph Sutro more than a century ago on land that is now owned by UCSF. The newly cleared and shaped paths form a network of signposted routes through what used to be a thicket unknown to all but a few neighbors and visitors.
Next fall, Dawson, his crew, and UCSF overseers will take their wilderness restoration project a step further. They plan to thin branches, bushes, and vines from a few small patches of the forest in hopes of eventually restoring some of the primitive fescue that covered the hill before the tree-loving Sutro began his late-19th-century planting binge.
For neighbors who own houses bordering the forest, however, the prospect of felling even a portion of their beloved trees is an outrage. "These plans would convert what is currently a dense, wild forest into a 'parklike' area," says Rupa Bose, a management consultant whose home is 150 feet from the forest's southeastern slope. She and other neighbors have protested the plan at UCSF-organized public meetings, warning that the modest tree and brush thinning might lead to landslides, the destruction of native forest creatures, and herbicide contamination.
What's more, "opening up the forest is likely to lead to increased fire danger," says Dirk Hoekstra, whose home nestles against the forest's eastern edge.
These perceived dangers are speculative, fanciful even. But they're consistent with a San Francisco quirk, where people feel comfortable with the idea of environmental preservation and restoration, yet become annoyed with its specific practice.
The city is home to the Sierra Club, and has backed largely symbolic environmental measures such as an anti-plastic-bag ordinance. But its residents are also notorious among park stewards for fighting measures that have the actual direct effect of restoring or preserving Mother Nature.
In 2003, when the National Park Service proposed clearing some trees in the Presidio to provide light for the endangered San Francisco lessingia flower, a local politician called federal park managers racist for uprooting "exotic" invasive species. When federal park officials attempted to enforce leash rules at a restored Crissy Field marsh that is habitat to the endangered snowy plover, pet owners established a nonprofit aimed at forcing the Park Service to let their dogs run free. And when California State Parks moved to preserve and restore native wildlife on Angel Island by culling eucalyptus trees during the mid-1990s, "people went nuts," recalls David Graber, chief scientist for the Pacific West region of the National Park Service.
Now people are going nuts over losing nonnative trees on Mount Sutro. And while that may sound like a silly parochial squabble, the tiny tempest atop Mount Sutro may presage a coming national debate over the environment.
On Sept. 10, the National Park Service released its "Climate Change Response Strategy," which explores the question of "how are we going to manage the physical landscapes of the national parks and seascapes in the face of global warming," says Graber, who is a member of the federal working group behind the report.
The jury is still out on the geographically specific consequences of global warming. But it's easy to imagine that rising seas may submerge wildfowl-habitat marshlands along the southern edges of the San Francisco Bay, while native grasses along the California coast may lose ground to heat-friendly invasive flora. So will the public support new, inland swamps? And should the government uproot plant life to re-establish the type of native grass-and-shrub fescues that used to cover western San Francisco?
To hear residents of Mount Sutro tell it, such measures would be fanatical, dangerous, and even ecologically misguided.
"We think it's quite possible to maintain the current system of trails to provide access to hikers and bike riders, while preserving the wild beauty of the naturalized forest, its mysterious sense of seclusion, and its fog-forest ecosystem," Bose wrote in an e-mail.
Dirk Hoekstra, who, like some of his other anti-tree-thinning neighbors, belongs to a "Speak for the Trees" Yahoo group, says thinning the eucalyptus will ruin Mount Sutro's trademark green patch, which can be seen from many parts of the city. "I've always found that to be very inspirational, regardless of where I've lived in San Francisco," he says. UCSF and the Sutro Stewards, he adds, "are interested in having a fairly large gash in that green core."
To naturalists, however, the modern result of Sutro's century-old tree plantings is a dying patch of invasive weeds. Native grasses and bushes have been crowded from the shady forest floor by ivy and blackberries. As the eucalyptus die, new ones won't sprout through the thick cover. Without natural restoration, these experts predict an environmental end game in which the hill is covered with a skeleton grove reminiscent of the kudzu-choked landscapes of the American southeast.
And as a Sutro Forest regular, I can tell you that moderate thinning of eucalyptus, blackberry, and ivy, coupled with reviving some native species, is not the cataclysm neighbors make it out to be. There's already a clearing at the top of Mount Sutro. And thanks to help from the Sutro Stewards and donations from the Rotary Club, it's now a gorgeous garden of native plants frequented on weekends by picnicking families. I, too, am fond of eucalyptus groves at Mount Sutro and Mount Davidson, and the way they're so thick as to create the illusion of wilderness isolation to hikers within. But I also love the spots in the city still covered in millennia-old fescue ecosystems, where 50 different plant species may reside in an area the size of a backyard.
"I documented 55 native species that have continued to survive" on Mount Sutro, says naturalist Jake Sigg, who volunteers on weekends with the Stewards. "They'fre still there. But most of them are about to go under."
Neighbors' concerns about fires, landslides, and wildlife destruction, meanwhile, are unfounded. Bose and others describe a theoretical scenario where thinned trees would retain less fog, be drier, and more apt to catch fire. Cutting eucalyptus trees would allow their roots to rot, and thus lose grip on the soil, provoking landslides.
"Instead of all these drastic and potentially dangerous choices, the best option would be, First do no harm," Bose wrote on her Save Mount Sutro Forest website.
But Mount Sutro is frequently bathed in fog irrespective of what types of plants are on it. Currently, however, the mountain is thick with eucalyptus, a hot-burning tree that, without thinning, could provide enough fuel for a blaze on the scale of the Oakland Hills fire.
During the Great Depression, city fathers actually encouraged woodcutting on Mount Sutro. "Part of that was because it was a fire danger," says Gray Brechin, a New Deal–era historian at U.C. Berkeley.
Its greatest landslide danger, meanwhile, stems from the fact the mountain is composed of layers of chert and shale, types of rock prone to slip against each other deep below any plants' roots. Now, thousands of tons of live eucalyptus press down on these rocks, actually exacerbating landslide danger.
Also important is the idea of preserving biodiversity where possible, even when other forces beat it back.
"I want the greatest number of plants and animals up there," Sigg says. "You can't have that without management."