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The Healthy Trees of San Francisco

September 26, 2011

The San Francisco Natural Areas Program (NAP) plans to destroy thousands of healthy trees in San Francisco’s parks.  The Draft Environmental Impact Review (EIR) for NAP’s destructive plan reaches the bizarre conclusion that removing thousands of trees will have no significant impact on the environment.   This conclusion is based on several fictional premises.  In a previous post we examined the fictional claim that all the trees that will be removed will be replaced within the natural areas by an equal number of trees that are native to San Francisco.  In this post we will examine another of the fictional premises:  that only dead, dying, hazardous, or unhealthy trees will be removed.

We have many reasons to challenge the truth of the claim that only dead, dying, hazardous or unhealthy trees will be removed:

  • The management plan for the Natural Areas Program tells us that young non-native trees under 15 feet tall will be removed from the natural areas.  By definition these young trees are not dead or unhealthy because they are young and actively growing.
  • The management plan has not selected only dead, dying, hazardous trees for removal.  Trees have been selected for removal only in so far as they support the goal of expanding and enhancing areas of native plants, especially grasslands and scrub.
  • The predominant non-native tree in San Francisco, Blue Gum eucalyptus lives in Australia from 200-400 years, depending upon the climate.(1)  In milder climates, such as San Francisco, the Blue Gum lives toward the longer end of this range. 
  • However, there are many natural predators in Australia that were not imported to California. It is possible that the eucalypts will live longer here:  “Once established elsewhere, some species of eucalypts are capable of adjusting to a broader range of soil, water, and slope conditions than in Australia…once released from inter-specific competitions and from native insect fauna…”(2)
  • The San Francisco Presidio’s Vegetation Management Plan reports that eucalypts in the Presidio are about 100 years old and they are expected to live much longer: “blue gum eucalyptus can continue to live much longer…”(3)
  • The Natural Areas Program has already destroyed hundreds of non-native trees in the past 15 years.  We can see with our own eyes, that these trees were not unhealthy when they were destroyed.

How have mature trees been selected for removal?

The EIR wants us to believe that only dead, dying, hazardous trees will be removed from the natural areas.  This claim is contradicted by the management plan that the EIR is claiming to evaluate.  Not a single explanation in the management plan for why specific trees over 15 feet tall have been selected for removal is based on the health of the trees.  Trees less than 15 feet tall will also be removed, but are not counted by the management plan.

  • Lake Merced:  The explanation for removing 134 trees is “To maintain and enhance native habitats, it is necessary to selectively remove some trees.”
  • Mt. Davidson:  The explanation for removing 1,600 trees is: “In order to enhance the sensitive species habitat that persists in the urban forest understory and at the forest-grassland ecotone, invasive blue gum eucalyptus trees will be removed in select areas. Coastal scrub and reed grass communities require additional light to reach the forest floor in order to persist “
  • Glen Canyon:  The explanations for removing 120 trees are:  “to help protect and preserve the native grassland” and “to increase light penetration to the forest floor”
  • Bayview Hill:  The explanation for removing 505 trees is:  “In order to enhance the sensitive species habitat that persists in the urban forest understory and at the forest-grassland ecotone, invasive blue gum eucalyptus trees will be removed in select areas.”
  • McLaren:  The explanation for removing 805 trees is:  “In order to enhance the sensitive species habitat that persists in the urban forest understory and at the forest-scrub-grassland ecotone, invasive trees will be removed in select areas. Coastal scrub and grassland communities require additional light to reach the forest floor in order to persist.”
  • Interior Greenbelt:  The explanation for removing 140 trees is:  “In order to enhance the seasonal creek and sensitive species habitat that persists in the urban forest understory, invasive blue gum eucalyptus trees will be removed in select areas.”
  • Dorothy Erskine:  The explanation for removing 14 trees is:  “In order to enhance the grassland and wildflower community, removal of some eucalyptus trees is necessary.”

In not a single case does the management plan for the Natural Areas Program corroborate the claim made in the EIR that only dead, dying, diseased, or hazardous trees will be removed.  In every case, the explanation for the removal of eucalypts is that their removal will benefit native plants, specifically grassland and scrub.  The author of the EIR has apparently not read the management plan or has willfully misrepresented it. 

The track record of tree removals in the natural areas

Although it’s interesting and instructive to turn to the written word in the management plan for the Natural Areas Program to prove that the EIR is based on fictional premises, the strongest evidence is the track record of tree removals in the past 15 years.  As always and in every situation, actions speak louder than words.

Hundreds of trees have been removed in the natural areas since the Natural Areas Program began 15 years ago.  We’ll visit a few of those areas with photographs of those tree removals to prove that healthy, young non-native trees have been destroyed.  This track record predicts the future:  more healthy young trees will be destroyed in the future for the same reason that healthy young trees were destroyed in the past, i.e., because their mere existence is perceived as being a barrier to the restoration of native grassland and scrub.

Girdled trees, Bayview Hill, 2010

  • The first tree destruction by the Natural Areas Program and its supporters took the form of girdling about 1,000 healthy trees in the natural areas about 10 to 15 years ago.  Girdling a tree prevents water and nutrients from traveling from the roots of the tree to its canopy.  The tree dies slowly over time.  The larger the tree, the longer it takes to die.  None of these trees were dead when they were girdled.  There is no point in girdling a dead tree.

    One of about 50 girdled trees on Mt. Davidson, 2003

  • Many smaller trees that were more easily cut down without heavy equipment were simply destroyed, sometimes leaving ugly stumps several feet off the ground.

    Bayview Hill, 2002

  • About 25 young trees were destroyed on Tank Hill about 10 years ago.  The neighbors report that they were healthy trees with trunks between 6″ to 24″ in diameter and therefore fairly young trees.  The trees that remain don’t look particularly healthy in the picture because they were severely limbed up to bring more light to the native plant garden for which the neighboring trees were destroyed.  The neighbors objected to the removal of the trees that remain.  The Recreation and Park Department agreed to leave them until they were replaced by native trees.  Only 4 of the more than two dozen live oaks that were planted as replacements have survived.  They are now about 36″ tall and their trunks are about 1″ in diameter. 

    Tank Hill, 2002

  • About 25 young trees were destroyed in 2004 at the west end of Pine Lake to create a native plant garden that is now a barren, weedy mess surrounded by the stumps of the young trees that were destroyed.

    Pine Lake "Natural Area" 2011

  • About 25 trees of medium size were destroyed at the southern end of Islais Creek in Glen Canyon Park about 6 years ago in order to create a native plant garden. 
  • Many young trees were recently destroyed in the natural area called the Interior Greenbelt.  These trees were destroyed in connection with the development of a trail, which has recently become the means by which the Natural Areas Program has funded tree removals with capital funding.

    Interior Greenbelt Natural Area, 2010. Courtesy SaveSutro

There was nothing wrong with any of these trees before they were destroyed.  Their only crime was that they were not native to San Francisco.  There are probably many other trees that were destroyed in the natural areas in the past 15 years.  We are reporting only those removals of which we have personal knowledge.

If you care about the trees of San Francisco….

If you care about the trees of San Francisco, please keep in mind that the public will have an opportunity to comment on the proposal to remove thousands of trees in the city’s parks.  There will be a public hearing on October 6, 2011, and the deadline for submitting a written comment is October 17, 2011*.  Details about how to comment are available here.

*[ETA:  The deadline for written comments has been extended to October 31, 2011, at the request of the Planning Commission.]


(1) Jacobs, Growth Habits of the Eucalyptus, 1955, page 67

(2) Doughty,  The Eucalyptus, 2000, page 6

(3) San Francisco Presidio’s Vegetation Management Plan, page 28

7 Comments leave one →
  1. February 3, 2013 7:23 pm

    I feel very uneasy about this idea that non-native beings “don’t belong” where they have clearly established themselves for years. We shouldn’t do this to people, and we shouldn’t do it to any living creature…especially trees!!!
    I understand they are taking up space that a native species could have dwelt. However, the San Francisco area naturally had very few trees before settlers came to the area. The planet as a whole is losing its trees. If we can accommodate any tree that can clean our air and beautify our cities, by all means lets support them AND the native species!

    And for goodness’ sake leave the decaying trees alone. They also play an important role in providing a healthy bed for new growth and the other creatures that support healthy forests.

Trackbacks

  1. San Francisco’s Natural Areas: The Many Mistakes in the Draft EIR | Save Mount Sutro Forest
  2. Killing Healthy Trees in SF’s “Natural Areas” | Save Mount Sutro Forest
  3. Response to Nature in the City « Death of a Million Trees
  4. Refuting Allegations – and a Politician who “Gets It.” « San Francisco Forest Alliance
  5. Sierra Club cranks up the smoke machine « Death of a Million Trees
  6. Scientists critique UCSF’s plans for Mount Sutro and native plant advocates react | Death of a Million Trees

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