Arlington County’s Urban Foresters performed a study on the value of our community’s trees. The county used the U.S. Forest Service program i-Tree Eco to assess the value of our urban forest. This baseline data can be used for making effective resource management decisions, support effective policy and set planting and preservation priorities.
This program used random sampling of 201 plots throughout the county, on public and private land, to best reflect the composition of our natural environment. Urban Forestry staff and volunteers surveyed from May through October to capture information. The study requires data on tree location, size, and health, as well as proximity to buildings, and other information.
i-Tree Eco is a software application designed to use field data from complete inventories or randomly located plots throughout a community along with local hourly air pollution and meteorological data to quantify urban forest structure, environmental effects, and value to communities.
A report is automatically generated by the Forest Service, which shows results from this study.
The report is available here:
Summary of the results
- Number of trees: 755,400 (45 trees/acre, a healthy natural forest has 40-60 trees/acre)
- Most common species of trees: Flowering dogwood, White oak, Red maple
- Most tree canopy cover, by species: Tuliptree, White oak, Red maple
- Percentage of trees less than 6″ (15.2 cm) diameter: 56.4 %
- Pollution removal: 235 tons/year ($3.59 million/year)
- Carbon storage: 204,000 tons ($27.1 million)
- Carbon sequestration: 9,630 tons/year ($1.28 million/year)
- Oxygen production: 20,687 tons/year
- Avoided runoff: 10,730,168 cubic feet/year ($717 thousand/year)
- Building energy savings: $1,020,000/year
- Avoided carbon emissions: 2,210 tons/year ( $294,000/year)
- Structural values: $1.38 billion
- Annual value in environmental benefits: $6.89 Million/year
Total value of our urban forest currently: $1.41 Billion (structural + carbon stored)
US Forest Service i-Tree page:
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