Tuesday, February 22, 2011

What do Trees actually do for Us?

My hometown has seen its share of large trees cut down for highway and sidewalk widening. Instantly the canopy is gone, the shade, the cooling effect, the beauty...

An excellent essay analyzes what a tree is worth within a cityscape and provides an overview of initiatives which have encouraged their planting. It's been a difficult battle convincing many decision makers about their value.

References are made to President Theodore Roosevelt, an ardent birder and conservationist, who delighted in creating or enlarging 150 national forests in the early 1900's.

City arborists had a tougher battle but several key initiatives like The Chicago Urban Forest Climate Project in 1994 and the Million Trees projects encouraged by the mayors in LA and NYC in 1998 added momentum to the importance of trees in a cityscape.

"As we humans wrestle with how to repair the damage we have wrought on nature, and how to slow climate change, urban trees offer an obvious low-tech solution. Every city should have a “maximally functional” canopy. We should shoot for a performance standard, like how many megawatt hours of air conditioning we can save, or how many pounds of nitrogen dioxide we can absorb, reducing ozone and smog. Trees can play a role in cooling cities while making them more beautiful, healthier, and friendlier to humans. And at a time when everyone seems to want to go “green,” urban forestry science offers meaningful ways to think about how to do that."

A scientist emeritus with the U.S. Forest Service, estimates, “We are only 50 percent of the way to knowing what trees really do for us.”

Essay in The Wilson Quarterly