3:28pm

Tue August 6, 2013
Health, Science, Environment

Mt. Sutro's eucalyptus trees raise question of how to manage urban forests

On a rare sunny morning on San Francisco’s Mt. Sutro, I went on a hike with Rupa Bose, webmaster of an organization called Save Sutro. Bose lives in the Forest Knolls neighborhood abutting the eucalyptus forest. Though she’s lived in the neighborhood for longer, she started exploring the forest a few years ago.

Bose told me that “it was a shock to me that you could come out of a very ordinary San Francisco neighborhood, with houses and cars and step into this forest. It has birds and the wind in the trees. . . It doesn't feel like being in the city at all, it’s simply gorgeous.”

She now hikes on Mt. Sutro a few times a week.

“I'm sorry it's not a foggy day,” she told me,  “because you should see this place when it's acting like a cloud forest. There's an understory of various plants, but I would say that blackberry predominates.

“There are some vines climbing up the trees,” she added. “I don't see any of them having reached into the canopy, they're just climbing the trunks. And I have heard that unlike kudzu, which climbs into the canopy, climbs out on the branches and strangles the trees, these ivies don't do that. They just climb the trunks and stay put.”

Later that week, I went on another hike up on Mt. Sutro. This time I was with Craig Dawson. Dawson grew up in the same Forest Knolls neighborhood where Bose lives now. He loves it up here, and has been exploring the hill for the past half-century; now, he coordinates trail maintenance and planting for the Sutro Stewards. He looks at the forest’s health differently than Bose, starting with the ivy.

“English ivy is one of the largest problems we have,” he said. “It kills trees eventually, over a period of years. People walk out here and see green, but there’s good green and bad green. When you evaluate a forest, and talk about management, you want to take a look at what is beneficial and what is harmful. Ivy is harmful.”

Two hikes up Mt. Sutro. Two conversations with people who love this place. Yet two very different perspectives on where it’s at now. And that’s at a crossroads.

UCSF, which owns the forest, claims the eucalyptus forest needs to be managed and thinned after years of neglect. Among other things, eucalyptus trees are a fire hazard. In fact, FEMA wants to pay for a grant to chop down thousands of the trees in the East Bay. The Oakland Hills firestorm that killed 25 people and destroyed more than 3,000 homes still smolders in Bay Area memories. But, like in San Francisco, debate over how to best handle an urban forest has delayed management plans for years.

To understand what’s happening on Mt. Sutro, I wanted to learn how the planted forest even came to be in the center of San Francisco. And that brought me to someone recognized as one of the city’s early leaders.

Adolph Sutro

In the 1860s and 1870s, a German immigrant named Adolph Sutro made millions in Nevada’s Comstock Lode silver mine. He came to San Francisco and invested in real estate--a lot of real estate. Sutro eventually owned one-twelfth of San Francisco--including what was then called Blue Mountain. Sutro called it Mount Parnassus, but it was later renamed Mt. Sutro in his honor.

To celebrate San Francisco’s very first Arbor Day in 1886, Sutro planted thousands of trees—mainly  blue gum eucalyptus—on his extensive property. Before he died in 1898, after serving as mayor of San Francisco, Sutro gave some of his land on top of Blue Mountain to what is now UCSF.

Over the years since Sutro’s death, the land has been used in various ways. It was logged and even hosted a lumber mill. Ishi lived there. For decades in the middle of the 20th century the forest was off limits to the public while the military used it for part of its Nike Missile Defense system. But from the late 1970s to the late 1990s, the forest was pretty much left alone.

An Urban Wilderness

On our hike, Craig Dawson told me about the wildlife that flourishes in the forest. “We have owls, there’s a couple different types. We have the hawks,” he said, “and you can witness that quite frequently along these trails, where you can find signs of something recently devoured.” He said someone even spotted a mountain lion a few years ago.

Barbara Bagot-Lopez, the director of community relations for UCSF, says that, while good for animals, the unchecked growth could keep it from meeting UCSF’s goals of having “a healthy forest, a safe forest, a beautiful forest, and an accessible forest.”

Concerned about liability from potential forest fires and unhealthy trees, the university developed a forest management plan in the late 1990s. Although it went through an extensive community feedback process, when the management plan’s draft environmental impact report came out last year, it sparked controversy. After the university held more community discussions, it postponed implementation of the plan until summer of 2014 at the earliest.

“We’re going to work to thin the trees and to remove underbrush so it's a more open understory,” she said, so “you can stand back and say, ‘Do I like that?’ Or ‘Do I not like that.’”

A Thorny Debate

Bose, of Save Sutro, does not like it. “So we're talking about removing around 90 percent of the trees per acre,” she said, speaking to the most severe scenarios in the draft environmental impact report.

“That will never happen,” said the Sutro Stewards’ Dawson of that amount of tree thinning. “It's just not a possibility.”

Regardless of the amount of trees that will be felled, Bagot-Lopez stands behind the management plan.

“We’ll have to see how people react to it,” she said. “The other thing about visual effects, and that isn't really something you can see immediately, but when you enable trees to thrive then their canopies open up more. They adapt the canopies and end up filling out, so it's much more fuller and much more healthier looking.”

Managing any urban space is not easy. The more people who use a space, the more opinions there are about how it should be managed, and the longer it can take to make any changes. Whether its users look forward to it or not, it seems that some of Mt. Sutro’s trees will be cut sometime next year.

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