Tree Canopy

What is Urban Tree Canopy?

Urban tree canopy is a measurement which encompasses the layer of leaves, branches and stems of trees that shelter the ground in a community, when viewed from above. This measurement is expressed as a percentage of ground area that is covered by tree crowns, and relates to the branching spread of the trees in an urban forest.

Why is Urban Tree Canopy Important?

Edmond Tree Coverage 02
Trees in general provide a large number of ecosystem services, environmental benefits that we directly experience by having trees planted throughout our city. Ecosystem services carried out by trees include:
  • Removal of pollutants from the air, soil and water
  • Release of water vapor into the atmosphere which cools the surrounding areas, mitigating the urban heat island effect
  • Interception of rainfall and reduction of storm water runoff (and thus, reducing the costs related to infrastructure required to manage it) 
  • Energy savings and reduced greenhouse gas emissions due to shade provided 
  • Carbon sequestration 
  • Increased property values
In addition to the contribution of these ecosystem services, trees provide other health, social, economic, and aesthetic benefits. The magnitude of ecosystem services is tied to the age, size and condition of the trees in the urban forest. Mature trees with larger crowns that are in good condition will provide more services than younger, smaller trees. As a result, a city with greater urban tree canopy cover (a larger network of trees) will experience more ecosystem services than a city with a lower canopy coverage.

Canopy Assessment

In 2012, Edmond Urban Forestry released the “Edmond Urban Tree Canopy Report”, which revealed the results from an urban tree canopy assessment performed on Edmond City Limits, also breaking the City down into 7 different land uses: Undeveloped, Residential, Open Space, Institutional, Commercial, Transportation, and Industrial. This initial assessment found that Edmond’s overall tree canopy percentage was 35.9. The highest amount of tree canopy for a land use was found in Residential areas at 46.2%, while Undeveloped areas (the largest land use) were a close second at 46.1%. Commercial areas had a tree canopy of 17.7%.
The full report analyzed factors that could potentially have a big impact on tree canopy in the future, and Urban Forestry has continued to promote the importance of planting and preserving trees throughout different land uses within the City. As conversations about Edmond’s tree canopy continued, Edmond City Council set forth an initiative to establish a tree canopy goal for Edmond in 2015. They placed this initiative on their Strategic Plan and began working with the Urban Forestry Commission to determine what exactly that goal should look like.
Tree Canopy Error Bars

Tree Canopy Benchmark

In October 2017, the Urban Forestry Commission delivered the following goal recommendation, along with a list of potential actions for supporting tree canopy:

“Implement and continue policy and programs that strive to increase tree canopy into the Optimal range (>40%), while preventing tree canopy levels from falling below the Baseline (37-40%) into the Critical range (<37%). Reassess canopy cover every 2-3 years in order to gauge progress.”

This goal was adopted by Edmond City Council as a Performance Benchmark on their Strategic Plan, initially in 2018.
The graphic shown to the above illustrates recent and current levels of tree canopy in Edmond. Ranges for canopy percentages have been assigned in order to allow for estimated statistical uncertainty associated with the assessment methods. Edmond’s overall urban tree canopy coverage is currently 37.3% (measured in 2018).

Drawing from existing assessments of Edmond’s tree canopy coverage, the goal serves as a benchmark for measuring progress in retaining and increasing tree canopy in Edmond. It allows for active monitoring of progress, so that policy and programs supporting tree canopy may be implemented and adapted along the way.

City Council will revisit the goal each year during their Strategic Planning workshop, and canopy assessment will be performed every 2-3 years by the Urban Forestry Department, to monitor progress.