UCSF plans to fell 30,000 trees in Mount Sutro Forest

This post has been copied with minor edits from http://www.SaveSutro.com, which is a website set up to inform people about Mount Sutro Cloud Forest and to defend it.


1. Write to the Board of Regents, who will ultimately decide whether to approve this project. Ask them why they are undertaking this controversial, expensive, and ecologically destructive project, and gutting a San Francisco treasure to achieve a “parklike” environment. You can contact the Regents at their website HERE. (Their email address is: regentsoffice@ucop.edu )

2. Write a comment on the Draft Environmental Impact Report. The report is HERE. (It will take some time to load.) The person to write to is Diane Wong, and her email address is at: EIR@planning.ucsf.edu

[Edited to Add: The comments are now closed. UCSF expects to respond some time in May 2013.]

3. Sign the petition to Save Sutro Forest (at the end of this article). PLEASE SIGN (if you have not already). The petition stays alive as long as the threat exists.

Mount Sutro Forest has approximately 45,000 trees in the 61 acres belonging to University of California, San Francisco (UCSF), and designated as an open space reserve. This dense forest, with an estimated 740 trees per acre, a sub-canopy of acacia, an understory of blackberry and nearly a hundred other plant species, is functionally a cloud forest. All summer long, it gets its moisture from the fog, and the dense greenery holds it in. Where it isn’t disturbed, it’s a lush beautiful forest, providing habitat for birds and animals, and a wonderful sense of seclusion from urban sounds and sights.

(CLICK HERE to see the Google Map of the forest.)

Mount sutro forest greenery


UCSF now has published a Draft Environmental Impact Report (DEIR) on a project to remove over 90% of the trees on three-quarters of the area. Only 15 acres – on the steep western edge of the forest – will remain as they are. Tree-felling could start as early as Fall 2013.

[Edited to Add:

Here is the PDF of the DEIR. Mount_Sutro_EIR_1-16-13_with_Appendices

Comments were due on March 4th, but because of the length and complexity of the document, neighbors asked for, and got, an extension. Comments are now due before March 19, 2013.]

On most of the forest (44 acres), UCSF plans to cut down trees to achieve a spacing of 30 feet between trees – the width of a small road – and mow down nearly all the understory habitat. On another 2 acres, they will space the trees 60 feet apart. The stumps of the trees will be covered in black plastic, or else poisoned with Garlon to prevent re-sprouting. Eventually, this will kill the roots, which will start to decay. We’ll address some of these issues in more detail in later posts.

Right now, we want to talk about the number of trees that will be felled. A spacing of 30 feet between trees gives about 50-60 trees per acre. A spacing of 60 feet gives 12-15 trees per acre.

(The easiest way to think about it is that each tree occupies a 30 x 30 foot space, or 900 sq ft. An acre is 43,560 sq ft, so this would give 48.4 trees to an acre. The DEIR calculates it as 61 trees per acre, assuming each tree occupies a circle that’s 30 feet in diameter, 707 sq ft. But there’s no way to arrange circles without wasted spaces between them, so this doesn’t exactly work.)

So on 44 acres, they will retain maybe 50 trees per acre (or maybe fewer). On two more acres with a 60-ft spacing, they will retain 12-15 trees per acre. All the rest will be cut down. Even using the DEIR’s overly optimistic calculation, they will be felling some 31,000 trees. Our calculations are closer to 32,000. Either way, it’s a huge number.

That means that in the 46 acres where UCSF will be felling trees, they will remove more than 90% of the standing trees.

The DEIR says that they will start by cutting down trees that are dead or dying. Aside from their value as habitat (some birds like woodpeckers depend on them), there are not all that many of them in Sutro Forest, which despite everything that has been claimed to to opposite, is a thriving forest. Next in line will be trees with diameters under 12 inches, or roughly 3 feet around – as thick as an adult’s waist. Then they’ll start on the larger trees. Since it’s going to be 90% of the trees, we expect thousands of large trees to be removed.


However, this is not all. We expect further tree losses for four reasons:

  1. Wind throw. Since these trees have grown up in a dense forest where they shelter each other, removing 90% of the trees exposes the remaining 10% to winds to which they’re not adapted. This can be expected to knock down a significant number of the trees not felled. Since the Plan only calls for monitoring the trees and felling any that seem vulnerable to wind-throw, it’s unlikely any vulnerable trees will be saved.
  2. Physical damage. Damage done to the remaining trees in the process of removing the ones they intend to fell. With such large-scale felling, damage to the other trees is inevitable, from machinery, erosion, and falling timbers.
  3. Something like AvatarPesticide damage. This forest has an intertwined, intergrafted root system. When pesticides are used to prevent resprouting on tree-stumps and cut shrubs and ivy, it is quite possible for it to enter the root system and damage remaining trees.
  4. Loss of support. Compounding the effects of the wind-throw, the remaining trees will suffer from a lack of support as the root network dies with 90% of the trees being removed. This could destabilize them, and make them more likely to fail.

What remains will be a seriously weakened forest with a greater risk of failure and tree-loss, not the healthier forest that the DEIR claims. It is likely that the long-term impact of the Project will be the elimination of the forest altogether, and instead will be something like Tank Hill or Twin Peaks plus a few trees.


The project is to be implemented in two phases. In the first phase, trees will be felled and the understory removed in four “demonstration areas” totaling 7.5 acres. They are shown on the map below in yellow, as areas #1-#4. (One of these, #4 “East Bowl”, is the two-acre area slated to have only 12-15 trees per acre.)

hand-drawn map not to scale

One area (#5 on the map) is supposed to be a “hands off” area to demonstrate the untouched forest. However, a trail has already been punched through it in November 2011, even before the DEIR had been published.

During this phase, they would experiment with the 3 acres on the South Ridge, just above the Forest Knolls neighborhood. On 1 acre, they would use tarping to prevent regrowth of felled trees; on 1 acre, they would use pesticides, particularly Garlon; and 1 acre they would trim off sprouts by hand. They could also use pesticides on the understory “consistent with city standards” – presumably those of the Natural Areas Program (See article on NAP’s Pesticide Use.)

In the second year, the plan would be extended to the remaining forest, with the proviso that not more than a quarter of the forest would be “thinned” at “any given time.”


Sign a petition to ask the Regents not to approve this plan.

Sign for Sutro Forest button

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9 Responses to UCSF plans to fell 30,000 trees in Mount Sutro Forest

  1. Tony Holiday says:

    I just posted this and my own horrified comments on the FB Website Sutro Stewards. First it didn’t show up, but maybe they just monitor posts. I tried four times and hopefully one of those times worked. Also posted to my own FB page. For whatever good it will do, but at least it could make some people aware of this. Jeez. It all sounds so drastic and expensive and for what reason? It just sounds like Glen Canyon all over again, as in overdoing it. We do not need developments or poisons or deforestation in our dwindling, precious forested parks!

  2. ronproctor says:

    Reblogged this on Ron Proctor’s Blog and commented:
    Shame on UCSF to take out healthy trees.

  3. harry says:

    Tony, it IS horrifying. What is with city management? Are they all climate change deniers? Sensible, knowledgable ecologists are recommending PLANTING TREES and REDUCING use of pesticides and herbicides – here we have the opposite!

    I live right near the forest and have no wish to either lose the forest OR be poisoned. People have their heads…in the sand. This is no time for this nonsense.

  4. Tony Holiday says:

    Okay – I just heard that the Stewards themselves are all in favor of this atrocity. Let’s get the neighborhoods in the area informed about what these crazies are trying to do to our environment and nip this in the bud: as in poisons, deforestation, loss of habitat, huge expense for no good reason — all WAY overdone. They can extend and improve trails, remove dead trees, and still have a bunch of native plants withOUT all this useless and idiotic destruction of this beautiful and beloved forest.

  5. Tony Holiday says:

    As mentioned, I got blocked from Sutro Stewards. I finally heard back from someone there who said I was misinformed and not to believe everything I read. And only one of my posts is left there, and the petition icon has been removed. If this is all on the up-and-up, then why did I get blown off like some dad saying to a little kid, “Because I say so, that’s why.” Why is it that they cannot be bothered, then, to tell THEIR side of what’s going on? So how can I HELP but think something’s fishy? If it were me I would put out a newsletter-rebuttal and let people chat about it back and forth on the websites. But since I got blocked and he wrote me off like that, well what else am I to think but that they’re trying to hide a lot of nasty stuff from the public until it’s too late for us to stop them…? WhatEVER they are up to, it certainly looks like no good even more than ever now. It’s like I was concerned about the Glen Canyon deforestation. I sent in something about this to another guy (not a Sutro Steward) who had a blog. He too just said I was mistaken and nothing more. So if they do this kind of thing, they expect us to just simply believe them and not continue to try to find out the truth on our own? So evidently there IS nasty bizness goin’ on with them and they’re hiding stuff – the bigwigs have their own agenda and care nothing, apparently, about the environment, this beautiful forest, and all the other nasty stuff like the poisons and animal habitats. I betcha they ARE planning to let the developers in somehow. If they can’t be honest with people and communicate and reply in a forthcoming manner, people are gonna really think they have evil intentions in mind more than they did in the first place!

  6. James Richard Tyrer says:

    Someone is probably correct that this is an unhealthy forest. It sounds like the description of a second growth forest. Such a forest will slowly change over time into a climax, or old growth forest, but a lot of trees will die for this to happen. Proper forestry (by knowledgeable humans) can help this process along. However, as stated, it is not possible to do this all at once. This is a gradual process that would take years, probably tens of years to accomplish. It does sound like there are too many trees. So, the thing to do is to remove the small trees — saplings less than 1.5″ –, and ONLY the small trees to start and very gradually remove some of the slightly larger trees and see how the forest develops. Sudden and drastic action can only seriously damage the forest. Pruning a forest is like pruning a tree, you can’t do it all at once; you will destroy the tree/forest.

    Webmaster: Thanks for your comment, James. If you were to walk through the forest, it would be evident that it’s thriving. It’s in the nature of cloud forests to be dense and lush. We understand that in a naturalized forest, self-thinning is the most adaptive and natural way, especially in terrain like Mount Sutro, which varies from acre to acre. Trees the forest cannot support will die, which is natural, and part of the forest’s ecosystem.

    That said, if they were removing only the smallest trees, the ones under 1.5 inches in diameter, we probably would not object so much. But that’s not what is planned. It would probably not work from a financial standpoint.

    When you have a Brontosaurus (the machine, not the dinosaur) in there, and a tree-felling crew, it’s economical to do all the work at once. The actions are more likely to be determined by funding than by any respect for the forest’s ecology. The only thing they’ve said is that they will do only a quarter of the forest at “any given time” – whatever that means.

  7. It seems a strange thing for the people who are proposing to remove 90% of trees in most of this small urban forest to claim that they are motivated by a concern for the forest’s “health”. I suppose that if it is gone altogether, there will be no more worries about it.

  8. Pingback: Thanks for the Great Turnout For Sutro Forest! | San Francisco Forest Alliance

  9. Pingback: Forests Store Carbon and Fight Climate Change | San Francisco Forest Alliance

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