Letters from the SAL: Did the Land Cover Change?:
On the surface it would lead one to think that planting 3000 trees resulted in the overall tree canopy increasing from 32% to 48% (over 17 sq km) in a relatively short period of time. This equates to 1.4 acres of tree canopy for each one of the 3000 trees planted. Even if natural growth is factored in this does not appear to be possible, particularly as some tree canopy would likely have been lost. The 2002 Urban Ecosystem Analysis was done by American Forests, and appears to be a pixel-based classification of high-resolution satellite imagery. The 2010 report from the Virginia Department of Forestry was based on the 2008 1m NAIP, with object-based techniques used extract land cover. Using two differing land cover sources to report change yields misleading information.