By Allison M. Heinrichs
Wednesday, April 16, 2008
“Pittsburgh has started to re-envision itself as a green place, and there’s been a lot of emphasis on green buildings here,” said Marijke Hecht, director of TreeVitalize, a partnership among Western Pennsylvania Conservancy and the city, county and state. “But trees are also a vital part of our green infrastructure.”
TreeVitalize, in conjunction with the city’s Shade Tree Commission, planted 15 trees of various origins in Lawrenceville on April 5.
“The truth is that Pittsburgh’s street tree population has been neglected for decades,” said Diana Ames, chair of the Shade Tree Commission. “Prior to the inventory, the last time there was a significant investment in our street tree population was in 1950.”Members of the Shade Tree Commission, which was re-established in 1998 by Mayor Tom Murphy after being dormant for more than 80 years, took a street tree inventory three years ago. Instead of the 45,000 trees they thought were in the city, members said the inventory found 31,000 trees — and 10 percent were dead or diseased.
The Shade Tree Commission outlined an $8 million plan geared toward improving street tree care and tree diversity, but a lack of funds has hampered its efforts.
The commission received help in 2006, when the nonprofit Friends of the Pittsburgh Urban Forest formed. Since then, the group has raised $1 million for pruning and maintenance, trained 80 “tree tenders” and participated in tree plantings. It plans to plant trees at eight Pittsburgh Public schools for Arbor Day next Friday.
“As old trees die or get diseased, we need to constantly be replacing them. There should be a diversity in our tree population,” Friends director Danielle Crumrine said.
TreeVitalize provides young trees suitable for city streets. Some are selected because they won’t grow tall enough to interfere with overhead wires, while others are more tolerant of salt and traffic.
The Friends group brings tree tenders to volunteer at plantings and help make sure trees receive extra care while they’re young.
“The first two to three years of a tree’s life are really important,” Crumrine said. “Having tree tenders on the ground mulching and pruning is critical.”
Ames, who also is Friends’ board president, said the group hopes to establish an endowment to help offset pruning costs when trees get too big for tenders.
City crews have performed the equivalent of $30,000 in work, digging holes to prepare neighborhoods for tree planting, said Dan Sentz, a city environmental planner.
“There are several reasons trees are important,” he said. “It used to be people just looked upon them as aesthetic features, but they’re good for energy conservation, storm water management, air pollution control, and there are also social benefits and property value benefits.”
THE CASE FOR TREES
Trees offer several benefits to an urban environment, including:
Cleaner air quality: Leaves filter the air, removing dust and absorbing other pollutants such as carbon dioxide, ozone and sulfur dioxide, and then give off oxygen.
Cleaner water and less polluted run-off: Trees reduce flooding by allowing water to seep into the ground slowly and preventing it from overwhelming sewer systems. According to a University of Georgia study, for every 5 percent of increased tree cover, stormwater is reduced by 2 percent.
Cooling cities: Trees alleviate the effects of heat by shading homes, streets and cars while releasing water vapor that cools hot air. This reduces energy consumption for air conditioning.
Enhanced community life: Trees create shady places for children to play and neighbors to talk, screen unsightly areas and support wildlife.
Increased economic growth: Trees lower energy bills and increase property values. According to a University of Pennsylvania study, trees increase home prices by 9 percent.
Source: Friends of the Pittsburgh Urban Forest
LACK OF DIVERSITY
Five types of trees make up the majority of Pittsburgh’s street trees
• Norway maple
• Red maple
• Callery pear
• Littleleaf linden
• London planetree
Source: Davey Resource Group
Allison M. Heinrichs can be reached firstname.lastname@example.org or 412-380-5607.