Keeping Tabs on a City’s Trees
One forester shows what it means to protect living, breathing trees in the urban environment.
Freshmen members of the University of Maryland wrestling team had an assignment: provide the tree for the team's Christmas party. To fulfill their mission, they trekked across campus and cut down a 35-foot tall eastern white pine. They dragged it almost a mile when, in front of the coliseum, the police stopped them.
To assess the damage--where the tree came from and what it was worth--the police called forester Mark Snyder. The request was Snyder's first as a forester working at the university. He laughs today as he tells the story of the wrestlers being ordered to pay $1,200, which the university then used to buy replacement trees.Thirty-three years later and now in his 13th year as the city of Eugene's urban forester, Snyder oversees the care, planting, and removal of all of the city's street trees.
"Connecting with people on a personal level helps build a rapport that enables them to connect to the trees in their yard, the trees on their street, their parks, their neighborhood, as well as many of the people who are their neighbors," he says. "Urban forestry is about building community through planting and caring for trees."
Tall and thin, with the build of an endurance athlete, Snyder is a stellar example of how the forestry profession has grown and changed since 1905 when Gifford Pinchot became the first chief of the U.S. Forest Service.
When Snyder graduated from forestry school in 1978, professionals regarded urban forestry as an oxymoron. "People didn't think trees were anything more than beautiful aesthetic amenities," he says. But just like light poles, gutters, and fire hydrants, trees are tallied as part of the city's infrastructure and accounted for the same way. It's part of an urban forester's job to keep track of and protect this city-owned inventory. Most medium to large cities now have an urban forester, sometimes called city arborists or village foresters.
Urban settings create all sorts of issues for maintaining trees. Power lines, inclement weather, and root obstruction are just a few factors on the foresters' watch list. Eugene's urban forestry program often works with local arborists on larger projects around the city. But urban foresters (who are also certified arborists, but focus on a collection of trees rather than individuals) do what they can to control potential hazard trees before they get out of hand.
"I've seen crazy stuff. I've seen tree houses built within a couple feet of high-voltage lines that if you touched you could die," says Ron Dyer, supervisor of Right of Way Vegetation in Eugene. Dyer's public utility program focuses on pruning trees away from power lines. He collaborates with the urban foresters on projects around town and works to inform the public about the hazards associated with power lines.
What's happening above ground is only half the battle for Eugene's urban forestry crew. "When I was a kid I thought tree roots went down to China," Snyder says. He explains it's a common misconception that tree roots grow down. In fact they grow out. The best way to imagine a tree's root system is to think of a large, Bordeaux red wine glass, he says. The large, top portion is the crown of the tree and the stem is the trunk. "Think of that wine glass sitting on a big plate or a platter," he says. He motions his upturned hand acting as this imaginary plate. This is the tree's root system. "It's all shallow," he says. "Ninety five percent of the tree root system is in the top 18 to 24 inches of soil."
Because of this, in particularly wet regions of the Pacific Northwest, uprooting becomes a major concern. "You hear the wind building and building. After doing it for awhile you get this intuition, that 'Oh boy, this is gonna be a big one,'" says Scott Altenhoff, co-founder of the Pacific Tree Climbing Institute. Altenhoff is also a board-certified master arborist and the lead arborist for Eugene's urban forestry operations. Altenhoff says that big trees are more likely to uproot when there is the combination of rain and wind. "The soil is somewhat lubricated, so the holding roots just slide through the soil and pull out," he says. "I've seen big trees split houses in two. Cars get crushed. We call them tacos when the tree hits right in the middle and the car folds around it."
The nature of the root system also makes choosing a location to plant critical to a tree's survival. "Right tree, right place," says Erik Burke, Eugene's director for the Friends of Trees program, reciting the mantra of many a tree organization. Where a tree is planted should determine what species would be the best fit. Planting a tree in a place with less than four feet between the sidewalk and the curb, what urban arborists call the planting strip, is virtually impossible. There's a city-approved street tree list that determines the size and species of tree that can be planted given its allotted planting strip size and soil type.
Burke says he'd like to see more planting of indigenous trees in the Eugene-Springfield area such as white oak, California black oak, bigleaf maple, and more conifers. But the conifer species emblematic of the area currently require a 20-foot planting strip, something Burke would like reduced to eight like in Portland. "Where it's appropriate with a large enough planting strip, we'd like to plant more valley ponderosa and incense cedar," he says. "We'd like the urban forests to have a real character of our region."