Arboriculture
Tree canopy
Tree canopy is the area of a city that trees shade when seen from above. Dayton says 70 to 80 percent of its canopy is on private property.
The City of Dayton's Urban Forest Master Plan page defines tree canopy as the areas of the city that are shaded by trees when viewed from above. Dayton says its canopy has declined, and that Ohio was among the first states hit by emerald ash borer.
The page also says 70-80% of tree canopy is located on private property. That is why the city asks residents for input. Canopy is a city-wide measure, so it differs from a single tree or street tree. See urban forestry for how cities manage trees. The post on the Dayton Urban Forest Master Plan and your tree lawn covers local effects.