Experts

National experts in trees and urban landscape walk Mass Ave to evaluate the trees and advise on our projects. We pass on this knowledge to the community through our education and outreach.

T. Davis Sydnor and Jim Urban, our principal advisors, have decades of practical experience with city trees and steps that government, business and citizens can take to “green” the nation’s cities.

T. Davis Sydnor
Professor, School of Environment and Natural Resources
The Ohio State University
PhD (Plant Physiology) North Carolina State University
The Ohio State University (1972-present)
Dr. Sydnor’s research has centered on the evaluation, establishment and maintenance of trees in urban areas and the effects of environment on plants in urban situations. He has developed interactive tools for managing urban vegetation. He is author or co-author of dozens of publications.

James Urban, FASLA
Urban Tree Associates, Annapolis, Maryland
Mr. Urban has written and lectured extensively; he helped to write current standards for urban tree plantings. He is credited with re-awakening landscape architecture to the skills needed to grow trees successfully in difficult urban soils. He was instrumental in developing structural cells [trade name: Silva Cells] for use under pavement. His new book, Up by the Roots: Healthy Soils and Trees for the Built Environment is published by ISA Books, Champaign, Illinois.

 

Key findings relating to the front yards of Mass Ave

Experts agree that trees tend to grow taller with broader crowns  in open areas where the roots can spread unhindered in good soil.* Didn’t we know this? Haven’t we seen fine old trees that thrive for eons in open land? Check out the huge trees on the National Mall, the US Capitol Grounds, or in Central Park in New York City.                                

Mass Ave has generous, 40-foot deep yards between the sidewalk and buildiing façades. These are not individually owned but a continuous strip of public land, known in city lingo as “the parking. “ They were created as open “park” when the avenue was built, to accommodate a second row of trees and to buffer people in the buildings from the noise and pollution of the street. Many of the lindens planted  in the parking  >100 years ago  enjoyed long lives. You can see how well they were growing in 1913. Some of these giants still stand.
Through trees added on our Planting Days, Restore Mass Ave is rebuilding  this  second row. Planting a second line of big trees will double the shade of the street trees. Trees in the yards will grow larger than street trees. They’ll

• absorb water from storms, lessening flow across pavement and drain backup
• absorb more pollution, helping DC meet federal air quality standards
• emit oxygen and keep the air cooler at ground level, for healthier air
• absorb carbon dioxide, the principal greenhouse gas in global warming
  

Bottom line: Embassy Row’s common civic space will be more improved – and Washington made greener– if major trees are planted in its open areas.

*	The Landscape Below Ground: Proceedings of an International Workshop on the Tree Root Development in Urban Soils. International Society of Arborculture, Champaign Illinois. Part I (1994), Part II (1998), Gary W. Watson, Editor. Urban, James. 1996. Room to Grow. Landscape Architecture: 86 (3)

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