Tree Canopy Estimate Questioned

Comments at Arlington County Board Meeting On June 16, 2018.

At the April 21, 2018 County Board meeting, civic activist Suzanne Sundburg blasted the County for misrepresenting the health of Arlington’s tree canopy. She said:

“Arlington’s claim of a 1 percent tree canopy increase between 2011 and 2017 is not statistically valid”—due to the wide 6 percent margin of error in the reported statistic.

Christian Dorsey dismissed Sundburg’s criticism of the County’s 2017 tree canopy study that reported this number. He said: “Getting into a misunderstanding about data points of a percentage point or two are not really useful for our public policy.”

Yet the District of Columbia Urban Forestry Administration (UFA) is embroiled in a controversy right now with Forest Service (USFS) researchers over a similar difference in reported statistics. Continue reading