An Inconvenient Plant

The Presidio is jointly run by both the National Park Service and the Presidio Trust, which means getting answers can be more than a little tedious. National Park Service officials claimed to have no idea how many trees they'll cut. Mark Frey, a Trust ecologist, estimates that perhaps 1,000 or more will be removed from Trust land over the next 30 years. Eyeballing a map, Terri Thomas, the Trust's director of park resources, states that the majority of trees to be cut are on Park Service land — meaning at least 2,000 (and perhaps many more) will go. Most of those trees, Thomas claims, would have died anyway in the coming decades.

The dune restoration plan's methodical pace is difficult to observe in real time, but a few dozen trees here and there add up over the years. The Trust has been removing around 100 trees a year for much of this decade; in 2008 alone, a minimum of 85 trees are scheduled to be felled. NPS spokesman Rich Weideman adds that the parks service's 2010 budgetary request from the federal government will include significant expenditures for tree removal.

That has neighborhood and tree activists grumbling. The notion of removing thousands of trees to provide sunlight for endangered bushes and grasses is as welcome to Presidio neighborhood groups as a family of sand dunes moving in next door.

"I find the nativism movement particularly disturbing, in large part because of its origins in Nazi Germany," wrote local native plant movement critic Steve Sayad in an e-mail. In a recent online debate with a plant aficionado, Sayad referred to native plant restoration as a "racist and sexist cult" befitting a "Green Nazi." Several other public critics of tree removal in the Presidio agreed that local native plant enthusiasts' ethos was derived from Nazism.

"Nazis, yeah. That's a term I've heard since day one," says Peter Brastow, a genial, red-bearded man who looks as if he strolled off a container of Ben & Jerry's ice cream. Now the executive director of the nonprofit Nature in the City, he was Chassé's predecessor at the Presidio, maintaining the Raven's manzanita site for more than a decade. "Nazi and fascist — yeah, I hear those terms a lot."

For the record, the Nazis were indeed enthusiasts of native plant gardens, and did extol the superiority of German plants. However, they actively sought to "Germanize" the landscapes of neighboring countries — the very opposite of the native plant movement's goal. Also, they killed people.

Certainly, not every critic of native plant restoration will quote the Nuremberg Laws. Yet the neighborhood and tree activists contacted for this story all described the Presidio's plan as an environmental misstep. "Removing trees of any species is pretty questionable these days in terms of global warming," said Isabel Wade, a founder of Friends of the Urban Forest and executive director of the Neighborhood Parks Council. Added Bill Henslin, cofounder of the antidevelopment group Friends of the Presidio National Park, "So many great old trees, which are good for the environment, are being sacrificed for some arbitrary aesthetic and historical goal."

These arguments are scientifically questionable. A 2002 study undertaken jointly by Colorado State University and the U.S. Department of Agriculture claimed that some grasses can store nearly twice the carbon that forests can. And a 2006 report by Lawrence Livermore National Laboratory demonstrated that planting trees outside the world's tropical zones actually raises global temperatures. Installing forested tracts over former grasslands — as Jones did 120 years ago in the Presidio — is especially troublesome: Dark forest canopies absorb sunlight, whereas shrubs and grassland reflect it.

But while scientific arguments can be disproved, emotional ones cannot.

"I'm assuming that an environmental argument has more validity than someone's aesthetic preferences," says Mary McAllister, a former member of the city's Park, Recreation and Open Space Advisory Committee and a public critic of native plant restoration. "But if it's aesthetics you want, I'll tell you that as far as I'm concerned, a forested and landscaped park is a more beautiful place than dune scrub and grassland, which is native to San Francisco."

As McAllister's view indicates, the fact trees didn't grow in this area naturally is of little concern to their advocates.