Importance

Trees function as critical infrastructure within cities by providing numerous benefits to city-dwellers – similar to streets and utilities – and should be planned for as such. The benefits trees provide include slowing storm water runoff, cooling temperatures, providing shade, protecting biodiversity and reducing air pollution, to name a few. There are numerous benefits to a healthy urban forest, including:

• Urban forests reduce air pollution by filtering particulate matter, reduce rates of cardiac disease, strokes and asthma, protect biodiversity and even support physical activity and social cohesion by creating places that are comfortable to walk, bike and gather.
• The urban forest is uniquely situated to help cities such as Denver manage the urban challenges of the 21st century like cooling and cleaning the air and providing shade to help combat heat.

Currently, Denver’s urban tree canopy coverage is 15%. This percentage decreases in downtown Denver, where tree coverage represents 4% of the total area. In urban areas like Denver, we can experience higher temperatures than our suburban neighbors because sun hits impervious surfaces like asphalt, tops of buildings, streets and sidewalks. When the sun hits these surfaces more heat is absorbed in comparison to vegetated surfaces, causing increased day and night-time temperatures. This cycle is often referred to as a heat island effect.

Trees combat heat and cool the air through evapotranspiration and shade. For example, the footprint of a 40-year-old American elm’s shadow is at least 60 feet wide. The shade from the elm, in addition to the transpiration from the tree, helps cool the surrounding area. Many trees acting together in this way can reduce the impact of urban heat.

The cooling effect from trees also benefits human health. Not only is it more comfortable to sit in the shade of a tree during the heat of summer, but the organization American Forests estimates that nationwide, city trees prevent approximately 1,200 heat-related deaths and countless heat-related illnesses annually. Learn more about how trees combat extreme heat, particularly in Denver’s historically underserved neighborhoods.

How we help Denver’s urban canopy:

The Office of the City Forester works with partners like The Park People, Office of Climate Action, Sustainability and Resiliency (CASR) and more to prioritize areas in the city that would benefit the most from new tree plantings. Together, we partner to plant trees in neighborhoods across the city.

Since the launch of the Be A Smart Ash program, the Office of the City Forester has planted more than 12,607 free trees for Denver property owners in the public right-of way. Help us combat heat by applying for a free tree for your public right-of-way to equip Denver with more shade and relief from the sun.