By Jan TenBruggencate
Advertiser Columnist

People plant trees around cities because it seems like a good thing to do, but it's tough to clearly identify a lot of the benefits of urban forestry.

A Kaua'i-based environmental education firm, NatureTalks, has received a $160,000 grant to do a nationwide study of tree-planting efforts by minority groups, with a goal of identifying how the people involved and the larger community benefit from them. The grant is from the U.S. Department of Agriculture's Forest Service, through its 2003 National Urban and Community Forest Advisory Committee.

NatureTalks is run by Colleen Carroll, who has a doctorate in environmental education and wrote the textbook "Growing an Educational Garden at Your School: A Study of the Hawai'i Experience," which was first published in 1998 and is being reprinted this year.

Carroll is also the former chairwoman of education at the National Tropical Botanical Garden.

U.S. Agriculture Secretary Ann Veneman said the $1 million grant program is an effort to promote the use of trees in cities and neighborhoods.

"Enhancing forests in urban areas will help improve the quality of the environment and quality of life in our urban communities," Veneman said.

Carroll said she plans to study about 30 tree-planting projects throughout the United States and possibly in a Pacific island region.

The projects will be selected by a committee. The title of her project is "National Assessment of Minority and Underserved Populations: Experiences in Urban and Community Forestry."

"We want to look at what was their experience, why it was important to them culturally," she said.

Trees aren't just places for birds to perch. Carroll said there are significant urban health benefits to having trees. They can help clean the air of dust and capture pollutants.

Some trees provide other benefits. Carroll said an O'ahu group being considered for inclusion in the study is producing what's called an "edible landscape."

Here, the plants have the additional benefit of providing something you can eat. They might be breadfruit or avocado trees, coffee shrubs and citrus, and groundcovers might be herbs that can flavor food.

That's a subject Carroll knows something about. She is working on a book on Hawai'i edible landscapes, in cooperation with photographer Keith Karasic.

For more information about NatureTalks, e-mail info@naturetalks.net. For more on the national urban and community forestry program, see the Web site www.treelink.org/nucfac.

Jan TenBruggencate is The Advertiser's Kaua'i bureau chief and its science and environment writer. Contact him at (808) 245-3074 or e-mail jant@honoluluadvertiser.com.