A few weeks ago, we’d mentioned seeing lots of trees along the Sutro Forest trails marked with orange blobs of paint. They were mostly trees in apparently poor condition, though they didn’t look especially hazardous. We assumed they had been tagged for removal and regretted it – these trees are part of the forest, and valuable as habitat.
Today, hiker Gina Hall posted pictures on Facebook of notes she found on these trees all over the forest: “Please don’t cut me down...” They suggested writing to UCSF Campus Planning, Box 0286 SF, California 94143-0286 – Attention Diane Wong. Before March 19th, 2013.
In the picture below, it says, “I am part of a collection of plum trees that bloom every year & provide a beautiful space in these woods. I am not dead.”
[Edited to Add: Another note on a tree, below. It says, “I might be dead but I am beautiful to look at and am a home to birds and other living things. Forests need dead trees.“]
“I didn’t write these notes,” Gina Hall wrote, “but I did read them all over the forest today…”
We’d also like to note that though public comments on the Draft Environmental Impact Report are due on March 19th, that is not the day tree-felling will start. We understand that will wait for the bird nesting season (which runs approximately February through August) to end. So please do write into UCSF – even if it’s after March 19. You could also address your notes to Ms Lori Yamauchi, Assistant Vice Chancellor for Campus Planning, at firstname.lastname@example.org or the same address as given above.
[Edited to Add the following section.]
WHAT CRITERIA FOR BLOBBING?
We don’t know what criteria were used for selecting trees for the orange paint blobs, or who decided. Hort Science, which did the original 1995 study of the forest has a specific assessment system for hazardous trees.
The method Hort uses for rating trees is this. It considers three factors:
- Failure potential (How likely is it that the tree would fall or drop a limb);
- Size of the part that would fail (the size of the tree or the branch);
- Value of the target area (if it fell, what would it damage?).
Each is scored on a scale of 1-4, and the scores are added together. This gives a tree a rating of 3 (least problematic) to 12 (most problematic). Only a small young tree far from any road or building or playground would be a 3. The City’s action threshold is 9, and most trees with a 9 or higher rating would be removed. This methodology is strongly biased against large trees in busy areas. For instance, a big tree near a roadway would get a score of 4 for size, and 4 for “value of target.” This means it is an automatic 9, because the score for “failure potential” cannot be less than 1. But conversely, it does not remove trees merely for being old or spindly or even dead.
Unfortunately, this is not usually the criterion used in San Francisco’s Natural Areas – or, presumably, Sutro Forest. There, they just eyeball the trees, and mark for removal any that are in poor condition or are leaning. We suspect the approach used here was just that – remove trees that are dead or dying or leaning.
This is a poor approach for a naturalized forest. It’s destructive of a forest’s ecology; dead and dying trees are important to a forest, and ones that lean add interest to the landscape.
(We have a query in to UCSF, and if they respond, we’ll post it here.)