Counting Trees

On Friday morning I attended an informational session on the current tree inventory that is being conducted for the City of Chelsea. The inventory is being led by the Urban Ecology Institute (UEI), though it includes a variety of other governmental and non-profit participants. The tree inventory is a count of street trees only, although aerial imagery is being analyzed at the University of Vermont to calculate total canopy coverage for the whole city. The survey is not complete yet, but preliminary results seem to show that Chelsea is seriously lacking in tree coverage - about 9% of the city's area is covered by tree canopy, compared to Boston's average of 29%. It is worth noting, however, that East Boston (where this author lives) had a calculated tree canopy coverage of only 6% when Boston's tree inventory was completed in 2006. The lowest in the city.

The vegetative cover in urban areas is vitally important for the healthy functioning of the city itself (i.e. mitigating storm runoff, moderating temperature extremes, reducing air pollution), as well as quality of life issues. Interestingly, the analysis for Boston, and the soon-to-be-released report on Chelsea, reveal the potential for a substantial increase in vegetative cover.

In 2007, the City of Boston announced a plan to plant 100,000 trees by 2020 with the goal of increasing the city's canopy coverage from 29% to 35%. While ambitious, it seems that Boston's goals are quite tame in comparison to other cities' tree planting programs.

The tree survey of Boston, and the one going on in Chelsea, are focused on street trees. However, according to UEI's John Walkey, Director of the Sustainable Cities program, street trees represent only 8% of the city's canopy coverage. The rest is on private property. This presents an interesting problem for devising policies to increase canopy coverage.