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Tree Walk: 13 Endangered Shade Trees at Washington Square Village playground

If the NYU 2031 plan is approved as is, the playground at Washington Square Village will be demolished to build a temporary gym and then a permanent academic building. The plan is available at http://www.nyu.edu/nyu2031/nyuinnyc/growth/the-plan.php. Among other losses if this construction occurs, will be the loss of 13 large-stature shade trees: two honeylocusts, five Norway maples, and 6 London planetrees. The trees provide extensive shade to an area that receives sun for most of the day.

Image: Washington Square Village playground.  Note that there are London planetrees outside the playground on its western and eastern boundaries.

The diameter-at-breast-height (in inches) of each tree is as follows:

Honeylocust 1 (northernmost): 18.5"
Honeylocust 2: 16.25

Norway maple (northernmost) 1: 16.7"
Norway maple 2: 16.25
Norway maple 3: 19.25
Norway maple 4: 17.75
Norway maple 5: 15

London planetree (northernmost) 1: 19.75"
London planetree 2: 19
London planetree 3: 15.5
London planetree 4: 18.5
London planetree 5: 18.5
London planetree 6: 20.25


The approximate ecosystem benefits provided by each tree were calculated using i-Tree Design, a USDA Forest Service tree benefits calculator available at http://www.itreetools.org/design.php.  I classified the maples and planetrees as in good condition while I categorized the honeylocusts as in fair condition because past pruning has reduced their natural crown.

You can also use the predecessor of i-Tree Design, the National Tree Benefits Calculator developed by Casey Trees and Davey Tree Expert Co. This calculator, available at http://www.treebenefits.com/calculator, provides property value information. It also provides energy information based on your input of land use type while i-Tree Design uses building age and other criteria to generate its energy calculations.

Below I have provided a mix of gross and specific information for each tree.

Honeylocust 1: 18.5"
$37 in overall annual benefits
$12.17 in air quality benefits
$12.01 in stormwater benefits = interception of 2, 413 gallons of stormwater this year
$1.80 in carbon benefits
At 23.5 inches in diameter, this honeylocust will provide $48 in annual benefits.

Honeylocust 2: 16.25
$32 in overall annual benefits
$14.47 (air quality)
$16.16 (stormwater)
$1.51 (carbon)

Norway maple 1: 16.7"
$26 in overall annual benefits
$12.17 in air quality benefits
$12.01 in stormwater benefits
$1.80 in carbon benefits

Norway maple 2: 16.25
$25 in overall annual benefits
$11.83 (air quality)
$11.45 (stormwater) = interception of 1,432 gallons of stormwater this year
$1.17 (carbon) = removal of 593 pounds of carbon this year
If this maple grows to 21.25 inches, it will provide $35 in annual benefits.

Norway maple 3: 19.25
$31 in overall annual benefits
$13.84 (air quality)
$14.77 (stormwater)
$2.22 (carbon) = removal of 726 pounds of carbon this year (Did you know that one person flying from NYC to LAX generates 1,400 pounds of CO2?)

Norway maple 4: 17.75
$28 in overall annual benefits
$12.84 (air quality)
$13.11 (stormwater)
$1.97 (carbon)
If this maple gains 5 more inches in diameter, it will provide overall annual benefits of $38.

Norway maple 5: 15
$23 in overall annual benefits
$11 (air quality)
$10.07 (stormwater)
$1.50 (carbon)

London planetree 1: 19.75"
$36 in overall annual benefits
$15.13 in air quality benefits
$18.93 in stormwater benefits
$1.84 in carbon benefits

London planetree 2: 19
$34 in overall annual benefits
$14.64 (air quality)
$18 (stormwater)
$1.77 (carbon)

London planetree 3: 15.5
$23 in overall annual benefits
$11 (air quality)
$10.07 (stormwater) = interception of 1,705 gallons of stormwater this year
$1.50 (carbon) = reduction of 473 pounds of carbon this year
At 20.5 inches, this planetree would provide $37 in overall annual benefits.

London planetree 4: 18.5
$33 in overall annual benefits
$14.29 (air quality)
$17.38 (stormwater)
$1.72 (carbon)

London planetree 5: 18.5
$33 in overall annual benefits
$14.29 (air quality)
$17.38 (stormwater)
$1.72 (carbon)

London planetree 6: 20.25
$37 in overall annual benefits
$15.46 (air quality)
$19.56 (stormwater) = interception of 2,445 gallons of stormwater this year
$1.89 (carbon) = reduction of 604 pounds of carbon this year

These 13 trees currently provide $398 in overall annual benefits to the block, the neighborhood, and the city, and I have not calculated energy savings and aesthetic (property) values.  Also, there are 17 crabapples and hawthorns for which I did not take any measurements.  These understory trees support birds, squirrels, and insects.  This is not to say that the honeylocusts (see http://www.plant-materials.nrcs.usda.gov/pubs/etpmcfs8420.pdf), Norway maples, and London planetrees do not support wildlife, only that I often observe wildlife use of the shorter canopy trees. Finally, the trees in the playground provide (as yet) immeasurable pyscho-social benefits!

Comments

gillian ware said…
great, thorough post- love it!
Georgia said…
Thank you, Gillian.

(Creating this post has made me consider enrolling in a graphic design class. I could make a more dramatic, visual statement if I had proper design skills.)
Excellent!
Here in Porto Alegre, Brazil, could save many trees from Gonçalo de Carvalho street. Many still do not understand the benefits of urban trees ...