City life is tough on trees, but the Department of Conservation and Natural Resources is exploring ways to change that.

Pollution, people and automobiles pose major threats to trees above sidewalks, but below the surface, compacted soil necessary to lay the footpaths surrounding trees often destroys the structure of the soil needed for the movement of air and water and the growth of plant roots.

Starting next week, downtown Harrisburg will serve as a test site for the use of a new material developed by Cornell University to address this problem. The material, called “CU Structural Soil,” is being used to plant trees at the Rachel Carson State Office Building at Fourth and Market streets, home to the departments of Conservation and Natural Resources and Environmental Protection.

“Earth Day and Arbor Day lead right into spring planting season, making this a great time to focus on the important role trees play in urban areas,” DCNR Secretary Michael DiBerardinis said. “Picture a tree-lined street, and then one without trees. Where would you rather work, live and shop?”

On April 20, Black Landscape Contracting and volunteers will be planting bare root Freeman Maples and Swamp White Oak trees on Third, Fourth, Chestnut and Market streets. Bare root trees are less expensive, retain roots and make planting by volunteers more manageable.

Mechanicsburg-based Black Landscape Contracting had to become licensed to produce the structural soil, which was used for eight trees on Market and Fourth streets.

Sites other than Fourth and Market streets are being planted without soil replacement as a comparison. Later this year, trees on Dewberry Street will be planted with root balls in structural soil.

The project to replace nearly 30 trees is a collaboration between the Harristown Development Corp. and DCNR’s Bureau of Forestry, with a $30,000 grant from Pennsylvania Community Forests.

“We applaud DCNR and our partners at PPL and the City of Harrisburg for using their resources, enthusiasm and cooperation for this exciting beautification project for downtown Harrisburg,” said Brad Jones, vice president for community development at Harristown Development Corp..

Twenty-six dead and dying trees were removed in March by PPL as a community contribution, and nine healthy trees were pruned. Work to remove sidewalk bricks in preparation for the plantings was done by youth from the Tressler Care Wilderness Center in Boiling Springs.

The project is to be completed by May to commemorate the 100th anniversary of the birth of Rachel Carson, the renowned writer and naturalist who is credited with the start of the environmental movement. Carson was born on May 27, 1907, in Springdale.

Additional partners include the Department of General Services and the City of Harrisburg departments of Parks and Recreation, Public Works, and Office of the City Engineer.

For more information, visit the Cornell Urban Horticulture Institute. For more information about urban forestry, contact Ellen Roane of the DCNR Bureau of Forestry at 717-705-2825 or eroane@state.pa.us .

4/20/2007