City trees seminar draws crowd

By Pia Hallenberg Christensen
Spokane, WA (December 24, 2009)- Most people like trees. Trees add structure to a landscape, and provide shade in the summer and places for birds and squirrels to nest. Sure, the leaves dropping in the fall is a little inconvenient, but other than that trees are widely perceived as a benefit to a yard and a neighborhood. On Dec. 16 the Urban Forest Council and the city hosted a free urban forest seminar to a standing room only crowd in the City Council chambers. City staff, landscape architects, gardeners and neighborhood activists gathered for a morning of tree education.

Kathleen Wolf, director of the human dimensions of urban forestry and urban greening projects at the University of Washington, gave an hour-long presentation on how the value of an urban forest really isn’t about timber. “What I offer today is not so much the ‘how to do this’ but the ‘why we should do this,'” Wolf said at the beginning of her presentation, which summarized 20-30 years of research. “I’m here to explain why making the choice for trees is a good business- it’s good business.”
Research shows, Wolf said, that shoppers are willing to pay a bit more for similar products purchased in a neighborhood with trees as compared with what they’ll pay in a barren neighborhood. Property with mature trees on it will sell for more than a lot without trees, Wolf said, and commercial buildings that are well landscaped can charge a higher rent and fill up faster than those without greenery.
“You can’t deny this: There is something going on here with people’s connection to trees,” Wolf said.
Urban trees- along streets and boulevards- are sometimes perceived as traffic hazards, but that, Wolf said, is not the case. “Trees are actually traffic-calming. People drive through a canopied street at a slower speed than if there are no trees,” Wolf said. “Trees don’t cause accidents; drivers cause accidents. The perceived risk of urban trees shouldn’t top the benefits of trees.”
During a short panel discussion, local landscape architect Len Zickler said he prefers to think of parking lots and the urban right of way as open space where trees can be planted. “But we need to create a healthy environment where the trees can actually grow; especially, we have to have good soil conditions,” Zickler said.
Panelist Mike Terrell, a landscape architect with Greenstone Corp., said it’s the experience of driving into a community that gets people to buy property- not necessarily the property itself- and trees help sell homes. “Often, mature trees in urban settings are ruined by a street that’s being widened,” Terrell said, “but do we really need wider streets? Maybe we should consider putting our streets on a diet instead.”
Chris Hilgert, from the Washington State University Extension Office, gave everyone a quick Trees 101 class that emphasized correct pruning techniques and how important it is not to damage a tree’s roots. “The roots are very sensitive to construction traffic and compacting,” Hilgert said. “A tree has 90 percent of its roots in the top 3 feet of soil because it needs the water and oxygen exchange that can take place there.”
A tree’s bark is also very sensitive and easily damaged. “Just under the bark is the cambium and the phloem, which moves water and nutrients to the leaves and the branches,” Hilgert said. “A little bit of damage can cause a lot of harm. The bark is like the tree’s skin, except that trees seal wounds, they don’t heal wounds.”
Spokane Conservation District forest program manager Garth Davis discussed the importance of taking care of already established trees and proper planting. “It’s so important that you plant the right tree in the right place,” Davis said. The city of Spokane Urban Forestry Program has issued a list of recommended street trees, categorized by size of tree and planting space, many of which can be seen at the Finch Arboretum.
Davis also mentioned that he’s seeing an epidemic of dying trees because of improper planting. “It’s important to make the planting space large enough for the tree,” Davis said, adding that removing turf around the tree and adding mulch instead is not only good for the newly planted tree, it also cuts down on lawn mower damage.
Steve Nittolo, horticulture supervisor for the city of Spokane, reminded everyone that urban trees enjoy a lot of protection under the city charter. “The city code already says that you cannot restrict water, air or nutrients to the roots of a street tree,” Nittolo said. “When urban trees are removed or diseased, they have to be replaced.”
Trees in the strip between the sidewalk and curb belong to the city, but their maintenance and replacement is the responsibility of the abutting property owner. “We are here to help you; punitive measures is not really what we are after,” Nittolo said, reminding the audience that street-tree pruning must be done by a certified arborist with a permit from the city.
Related Resources:
Spokesman Review- City trees seminar draws crowd
Community Context and Strip Mall Retail: Public Response to Roadside Landscapes
Videos from the Seminar: Overview of the Urban Forest, Trees 101, Ordinance, Trees Best Practices During Construction