SR-021208-13E13-E
February 12, 2008
Council Meeting: February 12, 2008 Santa Monica, California
CITY CLERK'S OFFICE -MEMORANDUM
To: City Council
From: Mayor Pro Tem Bloom and Councilmember O'Connor
Date: February 12, 2008
13-E' Request of Mayor Pro Tem Bloom and Councilmember O'Connor that the
Council direct staff to make recommendations regarding implementation of
revised procedures for analyzing appropriate mitigations for replacing City trees.
13-E
February 12, 2008
TO: Elaine Polachek, Community Maintenance Director
FROM: Walt Warriner, Community Forest & Public Landscape Superintendent
DATE: January 8, 2008
SUBJECT: Quantifying the environmental benefits of publicly owned trees and
diversifying Santa Monica's community forest
BACKGROUND
The Tree People have raised the question in an e-mail to Council members Bloom &
O'Conner about the environmental services trees provide and how soon, how much, and
specifically where those services should be replaced. Those suggested services include
air filtration, C02 sequestration, habitat for urban wildlife, watershed, flood protection, water
quality any significant energy conservation/cooling.
Although they understand that there is not an easy, standardized way to calculate those
services, they are raising the importance of calculating these services and developing a
comparable mitigation plan. This raises the issue of the lost tree services from the trees
that are removed, and ultimately regained by the new trees planted as part of the 2nd & 4th
Streetscape Plan. This could be applied to other street tree replacement projects as well.
Their point is that instead of 2 trees to replace 1, the calculations may show that the
replacements should be greater.
Their point to the City is that perhaps a services analysis should be conducted to help the
public understand the environmental impacts and costs of the decision to replace trees and
to determine an appropriate mitigation plan if necessary.
DISCUSSION
There are computer programs available to urban foresters today that allows for the
collection of data on urban forests in order to estimate the ecosystem services that a city's
urban forest provide. That data is used with local weather and air pollution concentration
data making it possible to calculate functional information. If a complete inventory is
conducted then the program calculates values for each tree and for the total tree inventory.
The program is currently designed to provide estimates of:
• Urban forest structure (e.g., species composition, number of trees, tree density, tree
health, etc.), analyzed by land-use type.
Hourly amount of pollution removed by the urban forest, and associated percent air
quality improvement throughout individual years. Pollution removal is calculated for
ozone, sulfur dioxide, nitrogen dioxide, carbon monoxide and particulate matter.
• Hourly urban forest volatile organic compound emissions and the relative impact of tree
species on net ozone and carbon monoxide formation throughout the year.
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• Total carbon stored and net carbon annually sequestered by the urban forest.
• Effects of trees on building energy use and consequent effects on carbon dioxide
emissions from power plants.
• Compensatory value of the forest, as well as the value of air pollution removal and
carbon storage and sequestration.
• Tree pollen allergenicity index.
Potential impact of pests such as insects or diseases.
The ability to report on the services provided is determined by the extent of data collected
for a tree inventory. The program requires specific types and amounts of data in order to
accurately project the benefits of an urban forest. And, the validity of results from the
program depends on the accuracy of the data collected.
Unfortunately, the City's tree inventory was not designed to provide that level of
information. Our inventory does include canopy size, which is a critical component for
determining environmental benefits, however their sizes were only estimated and therefore
the output of information on carbon storage and sequestration and air pollution removal
would only be an estimate.
At this point the City's tree inventory is 10 years old and in need of updating. Estimates to
conduct a tree inventory that would be able to provide the information on the services that
the City's trees are providing (i.e. air filtration, CO2 sequestration, etc) range from $9 - $11
per tree, for a total of anywhere from $300,000 to $375,000.
Based on the dafia provided by the US Forest Service its in 2001 Benefit-Cost Analysis
Report an individual ficus tree provides the following annual benefits:
Electricity savings $8.10
Change in Natural Gas usage $0.05
Net energy savings $8.15
CO2 emissions avoided due to energy use reductions $0.33
C02 sequestered as biomass $1.98
Net atmospheric CO2 reductions $2.32
Avoided pollutants $0.49
Pollutant uptake $9.36
Biogenic Volatile Organic Compound emissions $(0.68)
Net pollution uptake $9.16
Storm water runoff reductions $4.94
Total annual benefits per tree $44.20
Total annual benefits of the 23 ficus trees slated for removal $1,016.60
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While trees do provide environmental benefits, and it is important to be able to measure
them, the issue of diversification in terms of species and age is a much more pressing
issue because of the long term ramifications.
Santa Monica has an extensive urban forest. The city's public trees as well as its private
trees create a canopy over 15% of the City. Currently there are close to 33,000 street and
park trees, which translate to one tree for every three residents, a ratio that is substantially
greater than the statewide average. The street tree stocking level is 96%, indicating that
there are few vacant planting sites along Santa Monica streets. The US Forest Service
estimated that street and park tree canopy covers $% of the City and shades 25% of all
street surfaces. The asset value of Santa Monica's existing municipal forest has been
estimated on the low end to be worth $75.5 million ($2,582/tree, $815/resident) while the
City's tree inventory program estimates the value to be at $140,000,000 ($4,2421tree,
$1,51.1/resident). Either way you look at it, the City of Santa Monica's trees are arguably
the most valuable asset next to its employees and volunteer staff.
Santa Monica has over 220 different species of publicly owned trees along its streets and in
its parks. However, the ficus trees, which were planted between 30-60 years ago,
accounts for 10% of the inventory. This equals approximately 20% of the total asset value
(approximately $24 million) and they provide roughly 11% of all annual behefits. Clearly
this makes the ficus one of Santa Monica's dominant trees. That said, when you look at
the City's community forest from a broader perspective the stage is being set for future
problems if we do not create an urban forest that is diverse in species as well as age.
To provide some background; the loss of the American elm (Ulmus americana) to Dutch
Elm disease, which began in the 1930's and lasted well into the 1970's taught urban
foresters of the day the importance of species diversity. Because this one species was so
prevalently planted throughout the country its demise left a gaping hole which urban
foresters are still working at replacing. Moreover, in terms of lost services, the total cost of
removing and replacing these trees throughout the affected regions has yet to be fully
tabulated.
Unfortunately, the lessons of the American elm were not heeded by some cities. The
devastation caused by Dutch elm disease should have brought to attention to the dangers
of planting monocultures, or creating extensive stands of trees that consist of very few
species. During and directly after the loss of the elm, a replacement species was sought to
fill in the gaps left by dead elms.
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Instead of creating urban forests with a diversity of tree species, many municipalities
repeated the mistake of the past by over planting with only a few species. Those prevalent
plantings then became increasingly vulnerable to a build-up of other pests and diseases.
This is now the case in Michigan and its neighboring states where the Emerald Ash Borer
(EAB) is now killing thousands of ash trees and costing cities millions of dollars in
unplanned removal costs alone. Indeed .this was the case just a few short years ago here
in southern California with the infestation of the Lerp Psyllid which killed thousands of
eucalyptus trees and cost local cities millions of dollars. Fortunately for Santa Monica
because of its diverse pallet of eucalyptus trees relatively few eucalyptus trees needed to
be removed because of this pest. Prior to the Lerp Psyllid there were infestations of the
eucalyptus trees by the Eucalyptus Longhorned Beetle in the 1980's and pine trees which
were infested by bark beetles that led to the demise of thousands of pine trees in the
1970's. Locally, and more recently Santa Monica has begun to experience the demise of
large stands of Canary Island Date Palms, specifically in Palisades Park due to a species
specific pathogen. By the time the full effect of this pathogen is felt, Santa Monica could
very well be losing all of the Date Palms in Palisades Park and the surrounding area. This
can be directly attributed to lack of species diversity among the palm specimens in
Palisades Park.
Although the threat of known and established pathogens can be predicted and prepared
for, there is the potential of new pests invading the southern California which we have. yet
to learn about. Twenty years ago the eucalyptus tree was thought to be virtually pest free.
However in the past 5 years there have been several new species of insects that now
commonly infest eucalyptus trees.
Probably one of the biggest threats to our region by anew pest is the Asian Longhorned
Beetle (ALB). Most recently, infestations have been discovered in Brooklyn and Amityville,
New York, and in Chicago, Illinois. This insidious beetle is believed to have arrived in North
America in wooden packing material used for cargo shipments from China. To date, the
ALB has been found at 26 scattered warehouse and residential sites in 14 States around
the country. In 2006 Agriculture Inspectors ih California did discover a shipment that
contained the ALB which was subsequently destroyed. That being the case, the possibility
of an infestation occurring from shipments through ports along the west coast is very real.
One notable aspect of the ALB is that although it predominantly infests maples, it has also
been discovered in a variety of other species as well. What this means is that should the
ALB migrate into the southern California region, the potential for its spread throughout the
local plant palette is a very real threat. With no known chemical or biological defense
against this insect the potential of its further spread is a very real possibility.
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In addition to the threat of insects and disease infestations, there is also the additional
possibility of losing substantial numbers of trees to due to age. Currently, there are several
even-aged stands of trees throughout the city that are approaching maturity. Over 40% of
Santa Monica's trees are between 20 - 40 yrs old, with a good percentage of palms,
cedars and pines being older than that. Ideally, 30 - 40% of Santa Monica's forest should
be less than 10 years old, yet at this point only 15% of the city's trees are less than 10
years old. With over 40% of the city's ficus trees at 45 years of age or more, there is a
potential of losing large stands of ficus trees at one time in the near future. With the
average age of a street tree estimated to be 60 years, a 20 year replacement plan should
be established so that mature and over-mature trees are not removed all at once.
Eventually, these mature trees throughout the City will be reaching the end of their useful
life span at the same time and will need to be removed and replaced. Currently, there are
several stands in the city that need to be removed within the next 1 - 4 years. By planning
a phased replacement program, the current (and eventually) successive Community
Forester will not be faced with the need to replace virtually all of the Gity's over-mature and
declining trees all at once.
Urban forestry management requires planning beyond the current status of the forest and
plan beyond the current generation. The City of Sacramento uses a 50 year planning
interval, while San Francisco's Golden Gate Park uses a 75 year planning interval. In both
of these locations the urban forest is well established, prominent and highly utilized as the
need for long term planning has been addressed. That said Santa Monica would benefit
from a long term master plan to supplement the Community Forest Management Plan.
CONCLUSION
Although the need to determine environmental services by the City's trees is becoming a
critical issue, there is an over riding need to establish a long range plan to diversify the
city's forest in both age and species.
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' FES i 2 2Q48
Maria Dacanay
From: Clerk Mailbox
Sent: Tuesday, February 12, 2008 9:50 AM
To: Maria Dacanay
Subject: FW: myapologies--REVISED letter to city council regarding item 13-E tonight
Dear members of City Council,
When the Tree People raise a question about the environmental services our urban forest
provides, they point to a matterof great-- and increasing--importance to Santa Monica
residents..;The staff report suggests that accumulating adequate data necessary for such
calculations would cost hundreds of thousands of dollars, and that a much more important
priority is the need to establish a long-range plan to diversify the city's forest.
But--how can you make a plan without. having theinformation? You need the data in order to
make a plan--there is no other way to prepare a plan than to know what is involved. Flying
blind is no solution. And certainly not making a plan first, and THEN acquiring the data.
The staff report says:
"the stage is being set for future problems if we do not create an urban forest that is
diverse in species as well as age."
That is indeedcorrect. But since our urban forest is, as the staff report suggests, "our
most valuable asset next to its employees and volunteer staff," it is critically important
to the people that live here as well. And developing a long-range plan without proper
public input is a recipe for future conflict and upheaval. on thisissue, such as we have
seen with the Second and Fourth Streets streetscape plan, the problems on Yale Street, and
many othersgoing back fifty years. It is, in fact, essential that any urban forest policy
in our city incorporate extensive public input in its design, and that the resulting
policy receive oversight from members of the public as well as experts in the field.
The staff report addresses two issues: the supposedly meager financial benefits derived by
the 23 trees originally slated for destruction (no mention of the unidentified other trees
deemed "too large for relocation"), and the need to genetically diversify the urban forest
here.
The first item is based on 2001figures, but those are largely obsolete. Energy costs,
for example, have dramatically changed since then. But a much bigger issue hasto do with
the relocation of the other 51 trees: these trees provide specific benefits in their
present locations. It's perfectly fine to have a tree filter pollutants out at the
airport, but not if it stops doing that in the downtown area, where it is truly needed
(never mind spending hundreds of thousands of taxpayer dollars to yank out perfectly
healthy trees).
The fact that the staff report doesn't address the specific LOCAL impact of tree removal
means that the City Council lacks a truly critical tool in understanding what this plan
actually does to the neighborhood, and to local merchants and visitors: lack of shade,
inability to remove automotive pollutants, inability to retain stormwater drainage, for
example. Will west-facing shopkeepersface soaringair-conditioning costs when the trees
are removed? The store owners with whom I spoke were aghast at that realization, yet there
was no concern evident by city staff. Do retail customers prefer heavily-shaded trees?
Practically every study completed shows this to be the case, yet no studies were ever
consulted here. What about the residents--do they prefer thin shade--and no shade at all
during winter months, or do they wantfull-canopy evergreen trees? They were never asked
(few residents live within the 300-foot boundary specified in the present policy, and
city-wide the question was never raised).
It is simply not enough, in this day and age, to treat our urban forest along the simplest
technical lines--it's all very fine to focus on structural soils and the like (at which
Walt Warriner is a recognized authority), but we need a more comprehensive city policy
which is pursued, implemented and enforced, going beyond the basic technicalities of tree
maintenance. That is precisely what is lacking at present--and will continue to be lacking
if .the staff report is used as the sole basis for a new policy.
1 F t u i 2QQ8
This reflects a structural flaw in the policy-making workflow employed by City Council at
present: the council relies on practical technicians for the development of policy.
Technicians play a valuable role, but purely technicalabilities do not an urban policy
make . ~ -
The second item, the need for genetic diversity in our urban forest, is a sensible and
laudable objective. It SHOULD be included in an urban forest master plan. Unfortunately
the replacement trees on Second and Fourth are all of a single type, thus defeating the
genetic diversity argument. And besides, if the existing forest is aging and susceptible
to pathogens, why not plant new alternative young saplings in between, and let them grow
during the .final life- yearsof the present trees? When the old ones are gone, the new
ones will already be in place. In other words, the quest for genetic diversity in our
urban forest does not mean the destruction or relocation of healthy trees, regardless of
their age.
It's simply not necessary--in any plausible scenario-- to rip out perfectly healthy trees.
The staff report's call for a long-term urban forest policy in Santa Monica is an
extremely laudable goal. The problem is that the current Community Forest Management
Plan--the present urban forest policy-- is not being followed either in substance or
spirit. So if staff is now proposing a new plan, or a new policy, why should we assume
this one will in fact be followed? There is nothing in the staff report that suggests the
new policy will be implemented and enforced, or how it can be done. In fact, only
continuing public oversight will ensure that such a policy will be implemented.
The public's input in all phases of this revised policy is absolutely essential.
I believe we need a Santa Monica Urban Forest Commission, populated by interested and
qualified members of the public, as well as city staff and other experts. We already have
a Planning Commission, a Pier Commission, a Landmarks Commission and the Bayside
District.They help deal with valuable parts of our urban environment that are of critical
importance to the public. Our urban forest is likewise an extremely valuable asset, both
environmentally and financially--it is past time to stop these absurd wars between the
public and city government over saving our trees (and we've had several in the past few
years) --it's now time to allow the true interested parties--the public--to participate in
the actual decision-making.
To recap:
I. Updating the data on our urban forest is critically important.
Staff should explore whether the data can be obtained in stages-- perhaps divided by age
or geographical location--thus amortizing the cost over time.
2. Public involvement in the development of an urban forest is also enormously important.
The urban forest has become anessential asset to residents of Santa Monica. Ignoring
residents' wishes will undermine the intent of any long-range plan: public access to the
process must be easily available, detailed in its approach, and widely disseminated.
3. The public must also be involved in implementing and enforcing the urban forest policy.
Our current policy provides no mechanism for such involvement, thus allowing passing whims
to determine the shape and condition of our urban forest, without regard for the concerns
of residents.
Thank you for your attention
Daniel Jansenson
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