Feature
By Mark Rutherford
San Francisco spends millions each year on street trees—money well spent according to a recent U.S. Forest Service study that puts a price on our tree-related energy savings, environmental benefits and enhanced property values.
The San Francisco Street Tree Resource Analysis, an 80-page report published by the Center for Urban Forest Research at the University of California, Davis, confirms what many San Franciscans suspected—trees are good for you. As this report describes, not only were these arboreal benefits worth $7.5 million to the city in 2002, but for each of us there is always the “delight in knowing that street trees do improve the quality of life in San Francisco.”
So what is that Ulmus Parvifolia, sitting in its sidewalk cutout, collecting cigarette butts, really worth? Based on leaf area and canopy cover, this tree—also known as the Chinese elm—is the city’s star earner, averaging $361 a year in services rendered. The London plane tree was a distant second, at $146. The lowly maidenhair came in last, at $23.
Trees earn their keep in a number of ways, according to government researchers. They prevent wind from leaking into your home and whisking away costly heat (up to five degrees.) Shade cuts air conditioning costs. Street trees absorb pollution, scrubbing 2,271 tons of the greenhouse gas carbon dioxide from San Francisco’s air each year. They protect against erosion. Our leafy friends intercept more than 13 million cubic feet of storm water, and this alone saves the city almost a half-million dollars a year. The biggest benefits, however, accrue to property values. Trees added $6.9 million to the price of San Francisco real estate in 2002. There are also psychological, health, crime deterrent and other intangible benefits “that can only be guessed at.”
The study’s prodigious research also leaves no doubt that trees cost money. The San Francisco Department of Public Works (DPW) and other departments spent $4.77 million on the city’s arboreal assets in 2002, or $262 per street tree. This is “considerably greater” than the average $19 spent per tree by a sampling of 256 other California cities. On the other hand, the public, as well as nongovernmental organizations like Friends of the Urban Forest (FUF) that plant and maintain 81.5 percent of the city’s trees, spent $34 per tree on average. They were also much more efficient. Privately maintained trees returned $2 to the community for every dollar spent, while city- managed trees returned a mere 40 cents.
The biggest ticket item for city foresters was pruning, priced at $2.26 million in 2002. Litigation, administration and permitting hogged $1.83 million, or more than 38 percent of the budget. New plantings accounted for a mere $28,798.
There are an estimated 98,534 street trees in San Francisco, consisting of 115 different species, not counting those in your backyard or in our parks. Of the neighborhoods, District 8 fared best with 13,140 trees, downtown’s District 3 was the most barren with only 3,623. The city is on par with the “statewide average of 104 trees per street mile.”
This may not be the case forever. Street tree plantings are down by half since 2000. DPW planted 580 trees on publicly maintained streets in 2000, according to the San Francisco Bureau of Forestry; by 2002, it was down to 206 trees. Last year, the city bumped the number slightly to 224 plantings, and this year looks not much better, according to DPW forestry manager Tony Wolcott. Plus, as Wolcott points out, there is no net forestry gain since for every seven trees planted, ten are lost, and those tend to be the impossible-to-replace mature ones. On average, four times more trees are planted by private parties than by the city but, they also suffer the same loss ratio.
The report estimates approximately 127,500 sites left unplanted citywide. At the current rate, if left to the city, it will take more than 560 years to fill this void.
The opinions expressed in this article are those of the author and do not necessarily reflect the viewpoint of the SFAA or the San Francisco Apartment Magazine. Mark Rutherford is a San Francisco-based freelance writer. Copyright © 2004 by the San Francisco Apartment Magazine. All rights reserved.