One gorgeous tree and 15 lanes of roadway

木が人間の環境をもっと魅力的にしているのでしょうか。それとも、人間の環境が木をもっと魅力的にしているのでしょうか。

Do trees make the human environment more attractive, or do human environments make trees more attractive?

On an elevated pedestrian bridge just outside Iidabashi station, on the way to Koishikawa Korakuen, this gorgeous street tree and its fiery leaves caught my attention. It stands in front of two intersecting wide boulevards, two elevated freeways, and two shadowed canals. Not only does the tree soften the urban blight of devoting so much space to cars and their air pollution. I think the mundane and gruesome human environment also elevate the tree’s beauty beyond what it might attain in more pristine wildness.

Azabu Juban dead space in central Tokyo

Azabu Juban is one of Tokyo’s most central and most expensive neighborhoods. Arriving at the Tokyo Metro station for a meeting with a book editor, I was struck by just how unattractive the roadway is. In the opposite direction are small streets with traditional Japanese food, French cafes, and many charming places. But in this direction, there is a large swath of concrete plus interconnected elevated freeways.

This combination of high value real estate and astounding dead space also occurs nearby at Mori Building’s Roppongi Hills. I wonder if Japanese are particularly astute at ignoring the unaesthetic and directing their vision to the more attractive parts? How much more valuable would these neighborhoods be without the visual and air pollution caused by elevated freeways? How can a combination of private and public investment increase property and use values?

While freeway removal seems like the best solution, even hiding them with plants would greatly increase the property and use values below and adjacent to these dead spaces. An example are the beautiful mature ginkos in Sendagaya, at least when they are fully leafed out.

Portland’s Greenstreets add plants and reduce river pollution

Portland, Oregon is redesigning its streetscapes to create hundreds of new sidewalk plantings that capture stormwater runoff. As you can see in the photo from Portland’s Bureau of Environmental Strategy, these greenstreet projects not only relieve the burden on the sewer system from heavy rainfall, but also add plant life to public spaces, make streets more pedestrian and bicycle friendly, and provide habitat through native plant selection.

In addition to an excellent article on SF Streetsblog, the Portland city government does a great job of explaining the benefits of greenstreets:

^{When it rains, stormwater runoff that isn’t properly managed can flow over impervious surfaces picking up pollutants along the way and washing them into rivers and streams. Stormwater runoff can also cause flooding and erosion, destroy habitat and contribute to combined sewer overflows (CSOs).}

^{Stormwater management systems that mimic nature by integrating stormwater into building and site development can reduce the damaging effects of urbanization on rivers and streams. Disconnecting the flow from storm sewers and directing runoff to natural systems like landscaped planters, swales and rain gardens or implementing an ecoroof reduces and filters stormwater runoff.}

“Daylighting” Cheonggyecheon River

A great article in today’s New York Times about “daylighting” the Cheonggyecheon River in Seoul. Daylighting refers to uncovering streams buried under pavement. Three miles of elevated freeway were removed, a plant-rich stream restored, and central urban land was converted from car-centric to people-centric.

Benefits include:

• summer temperature reduction by 5 degrees Fahrenheit
• improved storm drainage, which global warming has worsened
• reduction in small-particle air pollution from 74 to 48 micrograms per cubic meter
• less auto congestion despite the loss of vehicle lanes
• bio-diversity gains include 25 versus 4 fish species, 36 versus 6 bird species, and 192 versus 15 insect species
• 90,000 daily visitors, including walking and picknicing
• higher real estate values for adjacent buildings
• political gains for former mayor, now South Korean President Lee Myung-bak (also formerly head of construction at Hyundai Corporation)
• restoration of the historic center of a 600 year city

Government officials and urban planners from Los Angeles, Singapore, San Antonio, and Yonkers have expressed interest in restoring urban streams. Sadly, the article did not mention anything about Tokyo, where most of its historic canals and rivers are covered by streets and elevated freeways.