permaculture

[Chris Carnevale <c.s.carnevale@gmail.com>]

http://www.postandcourier.com/news/2011/aug/08/city-street-trees-pay-their-way/

 City street trees pay their way: Forest Service study finds Charleston gets
good return on investment
By Robert Behre <http://www.postandcourier.com/staff/robert_behre/>
Monday, August 8, 2011

*Summary:* click the link above for the full article

The U.S. Forest Service has conducted two major urban forestry studies in
Charleston, South Carolina in the past decade or so.  One of which
inventoried the number, size and type of city street trees. The second, done
about five years ago, built on the first by calculating the costs and
benefits of the city's known street trees. The 2006 analysis -- done by the
U.S. Department of Agriculture's Center for Urban Forest Research -- puts a
price on how much trees give back by providing shade (and lowering cooling
bills), absorbing stormwater runoff to help the city's occasionally
inadequate drainage system, removing carbon dioxide from the air, and
offering aesthetic and other intangible benefits.

Dr. Greg McPherson, who was the center's director at the time, says, "Our
research in Charleston has shown that the municipal street trees provide
$717,000 in annual benefits, about $47 per tree, and only cost the city
$530,000 per year to maintain. That is a huge return on your investment."
In other words, for every $1.00 the City spends on its trees, it receives
$1.37 worth of benefits.  In the world of financial investing, a 37% return
on investment is ridiculously high.  The City now spends $1 million per year
and employs nine full time employees to tend 45,000 trees.

The city's trees provide intangible benefits, such as better-looking
neighborhoods, stress reduction, reduced crime, and recreational
opportunities, McPherson says. "If we could put a dollar value on these
kinds of tree benefits, Charleston's return on investment would be a lot
higher. Right now we can't, but we are working on it," he adds.

The genetic diversity and range of trees' age of the urban forest is not
ideal: seventy percent of those trees are comprised of just three
species--live oaks, crape myrtles, and Sabal palms--and age-wise the trees
are very young.  "We need to diversify," says Danny Burbage, head urban
forester for Charleston.  "But because they're so iconic, it's hard to
convince Charlestonians not to plant live oak trees."  But Burbage says too
many live oaks will leave the city vulnerable to some future disease that
attacks a single species.  "We could lose 35 percent of our tree population,
so it's good to have a diversity," he says. "There used to be a lot more
elms in Charleston."  Choosing the right trees for a street is a balance
between what the residents want and whether the city is aiming for a uniform
look or a mix of shade and color.

About a third line the city's streets; the rest are found in public parks
(West Ashley Park alone has about 2,000, while Hampton Park has about 1,000)
and in city drainage easements and public buffer zones.  The biggest threat
to the trees is construction but also Formosan termites pose a threat
becuase unlike native termites, they eat live wood.

Judging from old photographs, Charleston has more street trees now than ever
before.  That is likely because natural wooded areas are so much farther
away from the city streets nowadays because of outward development.

Charleston homeowners are fined big time for cutting down trees in their
yards.



*Cost-benefit analysis*

What it takes to maintain Charleston's street trees:

$35 Approximate cost to maintain a street tree per year (pruning, planting,
stump grinding, irrigation, administration, sidewalk and other
infrastructure repairs, etc.)

$47 Approximate value of a street tree, including:

$11 — value of its intercepting stormwater, helping the city comply with
federal stormwater rules.

$8 — Value of energy saving (both electricity and natural gas) saved because
of its shade.

$0.50— Value of carbon dioxide and other pollutants removed, released or
avoided by trees.

$26 — Value of aesthetics, property value increase and other less tangible
improvements.

$1.50 — Value of carbon dioxide sequestration and emission reductions, minus
carbon dioxide released during decomposition.

*Tending the urban forest*

Trees planted in the city last year: 354

Trees removed: 95

Trees pruned: 1,763

Source: Charleston's Urban Forester

*What they're worth*

$42.5 million – Approximate cost of replacing Charleston's street trees
(About $2,800 per tree)

Source: City of Charleston, S.C. Municipal Forest Resource Analysis by the
Center for Urban Forestry Research

*Tree contacts*

To request pruning, report a sick tree or inquire about having one planted,
call the city of Charleston's Urban Forestry Department at 724-7416.

Reach *Robert Behre *at 937-5771.

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