Why is an urban forest important?
Trees produce oxygen.
According to the Arbor Day Foundation, “a mature leafy tree produces as much oxygen in a season as 10 people inhale in a year.”
Trees clean the water, air and soil.
Phytoremediation is when plants are used to remove toxins such as metals, pesticides, solvents and gasoline from the air, soil and water. Trees absorb gaseous pollutants through tiny openings in their leaves and through pores in their bark, either storing the pollutants in their tissues or convert them into less harmful forms. Trees also intercept small particulate matter like dust, pollen and smoke, cleaning our air. “In Houston, TX the tree canopy was estimated to remove 60,575 tons of air pollutants annually with a value of nearly $300 million,” according to the USDA.
Trees Cool Off Cities.
Urban heat islands occur throughout cities because of the concentration of buildings, roads and pavement which trap and absorb heat, resulting in cities literally heating up several degrees. The heat island effect makes cities less livable, and can even pose serious health risks during heat waves.
How do trees affect the heat island?
Trees shade surfaces beneath them and transpire water, lowering air temperatures, in turn reducing ozone levels. Strategically placed trees near buildings can reduce the need for air conditioning and heating, thus decreasing power emissions while also saving the buildings’ owners money.
Trees Reduce Stormwater Runoff and Improve Hydrology.
During storm events, rain runs off into wetlands, streams, bayous, lakes and oceans, carrying with it the pollutants it picks up along the way. Healthy trees can reduce runoff by absorbing water through their leaves, branches and root systems. The positive effects of a healthy urban forest are endless.
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