Currently viewing the tag: "tree wiki’s"

June 11, 2012

To the Shoreline City Council

Regarding your proposed Tree Code Amendments, I wish to express my concern that they appear to do little to add tree protection to Shoreline.  My wife and I have owned a rental house in Shoreline for about 15 years.  My observation has been that trees continue to come down and replacement trees are not planted. One neighbor next door removed an evergreen tree taller than their house and a mature Mountain ash.  No replacement trees were planted. Several older Douglas firs have also been cut on other properties in the neighborhood and these are only ones I saw cut down and had firsthand knowledge of.

These first hand observations lend concern to your Urban Tree Canopy Assessment of March 2011. While the accuracy of evaluating canopy area has significantly improved by the 2009 study, I find it difficult to accept any statement that canopy cover is about the same as in 1992 and 2001.  As the study acknowledges the earlier studies are “rough estimates of canopy and impervious land cover based on coarse 30 meter resolution land use data “.  30 meters is over 90 feet or about a third of the length of a football field. Later it says that the 30% values for canopy “are approximates” and “This data is generalized and therefore not to be compared to the more detailed CITYgreen data.”

What this says to me is that you have a much more detailed and more accurate analysis based on the 2009 data that indicates a present value of about 30.6% canopy. This is below your stated goal of 35%. What you do not have are reliable comparison points because of the lack of resolution of the previous studies. You also state a goal of not losing more canopy.

Besides reducing the number of trees that can be removed over a three year period based on lot size you are really not increasing tree protection in my view.  This is particularly true when one considers that removing the prohibition on removing trees from undeveloped lots will increase the probability of more trees being removed. This is a step backwards and increases the probability of trees in remaining groves being reduced.

You put in place no mechanism for tracking trees being removed which is what a permit system does.  Requiring permits for trees over 30 inches to be removed only deals with one segment of the trees in the city. A 30 inch Douglas fir is going to be about 75 years old and 100 feet tall.  One problem here is that by only giving some protection to the oldest trees you allow younger replacement trees to be cut.  What happens when the old trees die if you do not have replacement trees to take their place. A healthy urban forest needs a range of tree ages and sizes for both replacement as old trees die and also for varied habitat for birds and insects. Bird species typically stratify in trees such that older Douglas firs for example actually have 3 different vertical layers of bird habitat.

I believe a permit system is the best way to track tree loss and also understand the health of your urban forest. It also functions to educate people about the value of trees. Such a system is important in maintaining a diverse habitat for wildlife and replacement. Such a permit system does not have to be cost prohibitive but can be set up as an online system with approval given online. Google street maps for example have street views which can be used to visually see things from a street level as well as Google maps viewing from space.

It also seems imperative if you don’t want to lose canopy and trees that you must require replacement of equivalent trees either on site or off site. While canopy may increase due to existing tree growth, without replacement you are decreasing the absolute number of trees as well as the potential diversity of trees.  From a stormwater runoff sense coniferous trees provide value year round.  Deciduous trees lose their leaves in the fall.  They provide little help in the winter. This is another reason to track tree loss, to see which species and what size trees are being cut down.

Another issue that needs to be considered is the use of native trees for replacement trees.  Native trees are supportive of native insect and bird species as well as adapted to climate and rain conditions in the NW.

Tree canopy as defined in your 2009 study is also only two dimensional whereas the value and worth of canopy to the urban forest is also based on canopy volume.  Cutting tall old conifer trees and replacing them with small trees like street trees are not an equivalence in value to the city in terms of the benefits different size and species of trees provide to the city and its residents.

Something Shoreline should look into is setting up a tree wiki like San Francisco and Philadelphia have.  It is an excellent tracking tool for change and a great educational tool for citizens, students, community groups and others.  You can check these out at these two links:

http://urbanforestmap.org/  and http://phillytreemap.org/

Seattle Audubon currently has a grant to start up a tree map wiki in Seattle. Joining this effort by adding Shoreline would be a great asset for both cites in trying to evaluate and protect the urban forest resources both have. I urge you look into this.

Steve Zemke

Chair – Save the Trees – Seattle

Note added for update:

On June 18, 2012 the Shoreline City Council by a vote of 4 to 3 did approve most of the recommendations of their Planning Commission, including reducing the numbers of trees that could be removed in a 3 year period from 6 on all lots to a variable 3-6 depending on lot size.  They also required a permit to remove trees over 30 inches in diameter at breast height.

for more information see – Of Paramount Importance - “Shoreline’s Trees: A triumph of Hope Over Fear”

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