What we lost...(or rather, what Metro Properties and the Allegro took):

Without writing an entire paper on the importance of the tree canopy—which has arguably, a greater importance in urban areas due to the decreased availabilty of space—I've discovered some good resources on the urban tree canopy here in DC.

Thanks to "Alaaro", another contributor to the CH discussion forum, I discovered the Casey Trees Endowment, which works on preserving and enhancing the tree canopy in the District. Here are just a few facts about the trees that were removed by Metro Properties, Inc., the developers of the Allegro:

There were 5 trees removed, which you can see on the graphic from the Casey Trees interactive tree map, which is one of the coolest things I've ever seen. I think they used their endowment to do a huge survey of all the trees in the District, which is just an amazing resource.


14th Street is running right through the middle of the graphic. (The yellow dot at the top on the west side of 14th Street is still standing, I believe) So, starting at the bottom left green dot and continuing north, here is some information on the trees that were removed.

Tree 1: Scarlet Oak

• Height = 40 feet
• Diameter at Breast Height = 14 inches
• Crown Radius = 15 feet
• Value = $3,597
• Tree was rated 1-2 in health, with 1 being the highest
  

Tree 2: Scarlet Oak (in a treebox near the street edge)

• Height = 50 feet
• Diameter = 27 inches
• Crown Radius = 20 feet
• Value = $8,387
• Tree was rated 3-4 in health (this was likely one that was due to be removed)

Tree 3: Scarlet Oak (set back near lot line - probably difficult to build around)

• Height = 30 feet
• Diameter = 17 inches
• Crown Radius = 15 feet
• Value = $4,499
• Tree rated 1-2 in health
  

Tree 4: Scarlet Oak (in treebox near street edge)

• Height = 35 feet
• Diameter = 18 inches
• Crown Radius = 15 feet
• Value = $5,023
• Tree rated 1-2 in health

Tree 5: Scarlet Oak (judging by health score, probably the other tree due to be removed)

• Height = 50 feet!
• Diameter = 28 inches!
• Crown Radius = 20 feet
• Value = $9,010
• Tree rated 3-4 in health
  

One of the niftiest thing about the Casey Trees site is that they've calculated and quanitified many of the environmental benefits of these trees. According to their calculations, here are a few interesting stats about the combined benefits of these 5 trees. (Values rounded):

• 4680 kg of carbon currently stored to date.
  
• 130 kg per year of carbon that would have been taken out of the air and stored over the next year due to growth
• 154 grams of Carbon Monoxide pollution removed each year
• 1356 grams of Ozone pollution removed each year
• $ 30,516 - total value
  

Compare that to a comparable newly planted Willow Oak over by the Giant. It's 2 inches in diameter and 15 feet tall, so it's a little smaller but pretty close to the ones that the Allegro proposes for replacement. After 2-4 years in the ground, we could probably expect numbers like these: 2 kg of carbon stored, .5 kg of carbon stored per year, 2.5 grams of CO removed each year, and 21 grams of ozone removed, with a value of roughly $70-$100. Multiply that by 6 and compare the numbers to the above figures:

• 12 kg of carbon currently stored to date.
  
• 3 kg per year of carbon that would have been taken out of the air and stored over the next year due to growth
• 15 grams of Carbon Monoxide pollution removed each year
• 126 grams of Ozone pollution removed each year
• $ 420 - $600 total value
  

DC has some great resources from the UFA, which you can view online at the UFA/DDOT site. I found this one to be of particular interest, called "Trees and the Construction Process...Basic Concerns and How to Avoid Problems" It appears to be a presentation that former UFA employee Ainsley Caldwell made to government workers and other construction and maintenance related departments.

WHY ARE TREES IMPORTANT?

• Trees represent a significant investment for the District in time and money
• DDOT spends more than seven million dollarsfor annual upkeep and tree planting
• Actual dollar value of the District’s street tree resource is estimated between 50-80 million dollars
  
• Trees can add 7–20 percent to the value of a home

Here's what 3460 14th Street NW once looked like, thanks to Google Earth: