Recently, we posted a reader’s note about a talk from the organization called ‘Nature in the City’ (NC) on the “urban forest.” (Those are NC’s quote-marks; they apparently don’t believe in urban forests). NC is the parent organization of the Mt Sutro Stewards, which backs the destructive plan to gut Mt Sutro’s Cloud Forest.

SE Farallon

These are our notes from that talk, which you can listen to here (scroll down until you find it). Given that it was positioned as “education”, we were disturbed by the strong bias as well as the inaccuracies. “A deep well of misinformation,” commented someone who heard the talk. We have to agree.

The only good tree?

NC’s Josiah Clarke kicked off with two slides: A shot of the nearly bare Southeast Farallons, and a “bunch of logs” (similar, not identical, to the pictures here).  “I’m definitely not a hater of trees…” he said, noting that the pictures reflected his “background with trees”.

Native plant toyon and eucalyptus

NC then listed all the ways in which non-native trees are bad: they shade the ground; they provide a perch for raptors (of which more later); they make the soil more acidic so native plants can’t grow under them; and through allelopathy, they poison the soils around them so only blackberry, ivy and holly can grow. [Not quite. Here’s a picture of toyon, a native plant growing under non-native eucalyptus.]

In addition to eucalyptus, NC dislike black acacia. “Very allergenic,” they called it, in addition to being non-native and invasive. [Not really. It’s mildly allergenic, less so than oak. The AAIFNC notes that acacia is a “Minor cause of pollen allergy February to March…” while Oak is listed as a “Major cause of pollen allergy March to May…”]

NC referred to non-native trees as “deadweight” and “stagnant trees,” and made sweeping assertions about their lack of contribution to the eco-system. [In fact, Mount Sutro Cloud Forest has 93 species of plants. California’s eucalyptus forests have complex eco-systems – especially one as old as the Sutro Forest. No one has surveyed its fauna, particularly insects and reptiles. The forest is full of songbirds, both in the canopy and the dense understory, while we have seldom seen more than one or two individual birds on the Native Garden on top.]

And for “tree-huggers” who objected to the destruction of century-old heritage forests, NC compared the 120-year-old trees to “toxic waste” and “broken-down old buildings.”  They also disparaged anyone who mourned the thousands of trees cut down at Inspiration Point…

Other things they weren’t a hater of (but obviously didn’t like):

• Great horned owls. “More common now than they’ve ever been.” They believe they endanger the weasels, brush rabbits, shrews, and quail that are “on the brink and disappearing.” [No, they’re not, actually. All those species are quite common, with a Conservation Status of “Least Concern.”]

• Hawks, red-tailed and red-shouldered, because they’re predators and they’re not rare. [True. Neither are any of the species NC apparently root for.]

• Ravens, because they’re predators; they saw one eating a sparrow. “We’re managing for ravens” NC said disparagingly, which was odd because as enthusiastic birders, they should know that San Francisco has quite a number of bird species.

The only bird he seemed to favor were Nutall’s white-crowned sparrows and rose-breasted grosbeaks, but not enough to support the mature trees the latter prefers. (The grosbeak shows up at feeders in Cole Valley at the edge of the Eucalyptus forest. Check this link for a picture – scroll down. It also notes that 30 species showed up at Craig Newmark’s Cole Valley bird-feeders… hardly evidence that “we’re managing for ravens.”) And quail. [None of these birds is rare, either; they’re all listed as being of Least Concern.]

He showed a picture of a toyon and a band-tailed pigeon. “This is the lock and key mechanism” he said, implying that they were interlocked elements of an eco-system. [Umm, no. The band-tailed pigeon will eat any kind of berry or seed and it loves bird-feeders. Also, it’s a forest bird, not a chaparral-dweller. And toyon berries are eaten by many kinds of birds – and raccoons, all of which help spread its seeds.]

Actually, NC wasn’t so keen on some native trees, either, with a reference to over-planting of redwoods in the artificial canyons of downtown San Francisco.

NC advocated cutting down existing non-native trees and replacing them with specific native trees. [Most would be unsuitable for the conditions of our city. Douglas Fir requires much more rain. Oak doesn’t like wind, and is susceptible to Sudden Oak Death, besides being allergenic. And so on.]

NC favors these:

• The endangered Mission Blue Butterfly [but apparently does not object to toxic chemical use where it pupates at ground level, or where the ants that tend its 3rd and 4th instars live];

• The Nutall’s subspecies of the white-crowned sparrow [no conservation status, noted as common and flexible];

• The Callophrys Dumetorum butterfly [not the Callyphors Dumetorum as NC misspells it on their website] which NC calls the Green Hairstreak, but UC Davis calls the Bramble Hairstreak. However,  Butterflies and Moths of North America refers to it as the “Coastal Green Hairstreak” and describes it as “G5 – Secure – Common; widespread and abundant” though it notes its range is limited and should be protected.

NC said that the governing principle of conservation should be to preserve the “last of the least and the best of the rest.” We have no quarrel with that principle. But in fact, none of the species favored, (or even the species disfavored), fall into these categories. With the single exception of the Mission Blue.

Actually, the Green Hairstreak Corridor is a good idea, whether or not the butterflies (whatever they’re called) are rare. We’re supportive of efforts to preserve nature in the city — but not by destroying it.

We’re puzzled why the Nativists in San Francisco don’t work with nature rather than against it – for instance,  underplant urban forests in Golden Gate Park with those native species – such as ferns – that prefer shade and moisture, rather than trying to create “sunny glades” where the sunshine is limited and toxic chemicals are necessary.

We’d suggest an over-riding aphorism: First, do no harm.