Pressure to preserve tree canopy heats up

By Megan Rolland
Kansas City, MO (July 15, 2007)- Drive in downtown Kansas City and you’ll find yourself in the tropics- up to 8 degrees warmer than many of the city’s neighborhoods or suburbs. The reason: More concrete, fewer trees. Throughout the area, concrete is increasing and tree cover is declining as development claims wooded areas and older trees die off. “It’s alarming that we’re losing trees,” said Joan Steurer, air-quality planner with the Mid-America Regional Council. “We’re not even staying even.” The threat to the tree canopy has officials working on finding ways to reverse that trend.

Across the nation, scientists and government officials also are taking note of the threat to urban forests and the important role they play in decreasing temperatures, reducing pollution and protecting against floods. A study soon to be released measures the canopy over cities- 26.4 percent of Kansas City is covered by trees. That’s not bad, according to preliminary figures from the urban forest division of the U.S. Department of Agriculture. Some cities have less. But according to at least one other study, Kansas City has reason for concern.
About 2,500 trees under the care of the Kansas City Parks and Recreation forestry department die every year. No replacement program exists. Forester Kevin Lapointe with the parks department is asking for an increase of $3 million next year- and more later- to replace the dead trees and plant an additional 10,000 trees a year. “Trees are once in a lifetime,” Lapointe said. “When you defer planting a tree, you can’t make up that lost time.” That’s because the benefits felt from a mature tree are significantly greater than those of saplings, he said.
In all, the roughly 415,000 trees on city property save an estimated $51.2 million a year, according to the parks department. They absorb enough heat to significantly lower energy use and absorb enough rain to significantly lower storm water runoff. They also absorb greenhouse gases such as carbon, make the city more attractive and eliminate other pollutants.
Steurer and scientists make a direct connection between the small number of trees in urban areas and the creation of ground-level ozone, a chemical reaction that requires heat and light. Kansas City recently violated federal clean-air laws because ozone levels were too high. Researchers are especially concerned about the “heat island” effect. As buildings and streets absorb energy from the sun, downtown Kansas City gets up to 8 degrees warmer than greener parts of the city, said Jimmy Adegoke, a climatologist with the University of Missouri-Kansas City. That extra heat in the summer increases energy use as downtown buildings crank up their air conditioning.
As for any concerns that reducing a city’s heat might make it more vulnerable to tornadoes, that’s a common misconception, said Mark O’Malley of the National Weather Service in Pleasant Hill. Temperature has no effect on a tornado’s path, he said.
Previous studies have found that on average, cities in forested regions have 34.4 percent canopy cover, cities in grasslands 17.8 percent and cities in deserts 9.3 percent, said David Nowak, project leader for the urban forest division of the Department of Agriculture. Nowak said Kansas City is difficult to fit into any of those categories, but it can be compared to some other cities. Kansas City’s canopy measured at 26.4 percent, compiled from satellite imaging, with a 2.5 percent margin of error.
A few other cities and their tree coverage: Atlanta, 36.7 percent; Washington, 28.6 percent; Minneapolis, 26.4 percent; New York, 20.9 percent; Philadelphia, 15.7 percent; and San Francisco, 11.9 percent. On the outskirts of such cities, urban areas are expected to grow enough in the next 43 years that the sprawl would fill Montana, Nowak said.
Urban foresters say cities need to adopt tree ordinances to preserve existing canopy and also to ensure that developers plant trees to create canopy in new areas. “It’s a little bit scary in a way,” said Lisa Burban, an urban forester for the USDA Forest Service in the Midwest. “Some cities may not have the awareness, so you could lose an entire city forest.” Chicago, Minneapolis, Boston, San Diego and New York all have launched programs aimed at protecting their tree canopy.
A big part of those movements is a push to increase the number of street trees maintained by the cities, but those trees account for less than 20 percent of the canopy. The rest are on private property, in the hands of residents or commercial property owners. Because a majority of trees are privately owned, Burban said, regulating them is a critical part of maintaining the urban canopy. There seem to be two types of ordinances- those that restrict cutting down trees, and landscape requirements aimed largely at developers stipulating the number of trees to be planted near buildings, homes and streets.
But many developers are working to preserve trees of their own accord, said Charles Garney, CEO and owner of Briarcliff Development Co. Garney has built streets around trees in order to preserve them, and he frequently consults an arborist to ensure trees aren’t damaged during construction. “It challenges you to keep everything green, but we’re dedicated to it,” Garney said. Garney said he’d be in favor of ordinances that make developers pay more attention to trees, but he was concerned that too-strict rules might hinder growth.
A quick look at some of the efforts being made by Kansas City and some suburbs:
* Kansas City: Kansas City doesn’t have ordinances that regulate removing or planting trees during development. “If a developer wants to go out and clear-cut a site, then the city really has no way to prevent them,” said Patty Noll of the planning department. But city codes are being updated, and Noll said the trend is to make the policies greener. For example, Noll said, the city is drafting an ordinance that will require planting one tree along every 30 feet of street frontage and a variable number of trees in parking lots in new developments. The planning department also has proposed an ordinance that would make it difficult for trees near streams to be cut down for development. And Noll said she would like to see an ordinance that would require tree surveys and restrict the cutting of some trees.
* Olathe: The growing suburb has a tree preservation ordinance that is stricter than many in other cities, but Rick Spurgeon, the Olathe city arborist, said the law still is too weak. He said trees have been cut down in Olathe that were the oldest or largest of the species in the state. The rules in Olathe give developers incentives to preserve trees, and require developers to plant one tree every 20 to 40 feet along the street, as well as in landscaped areas in parking lots. In residential developments, at least three trees are required for every single-family dwelling.
* Lee’s Summit: Lee’s Summit just reinstated its tree board in an attempt to catch up with a 10-year span when the city wasn’t spending much money on trees on city land. Foster Paulette, superintendent of park development, said the city wants to qualify as a Tree City USA from the National Arbor Day Foundation, which among other things requires a forestry program with a budget of at least $2 per capita.
* Overland Park: The suburb has a goal of planting 500 to 1,000 trees annually and is completing an inventory of city-owned trees. “We knew we had this valuable resource out there, but we didn’t know its worth or what we had,” said Greg Ruether, manager of the Parks and Forestry Department.
For the full article, visit Kansas City Star.