The average street tree can:
- absorb 34,000L of stormwater
- filter 27kg of pollutants from the air
- reduce asphalt temperatures of carparks by as much as 13°C.
- not only provide shade but also function as a ‘cooling tower’. As water evaporates from the leaves during transpiration, air that passes over the leaves is cooled.
- trap more of the sun's energy than any other group of organisms on earth. They are in essence big batteries - the largest on earth.
- Of the sun's energy trapped by organisms, trees account for 50% of that energy. (Erv Evans, North Carolina University)
Additional benefits:
- Trees are both the largest and longest lived group of organisms on earth.
- They improve aesthetics of and provide screening.
- Reduce glare in urban streets.
- Trees prevent crime! From 2005 to 2007, the U.S. Forest Service studied the correlation of crime and the presence of trees in Portland, Oregon. They found that areas with larger tree populations experienced lower crime rates than areas with smaller trees.
- It was speculated that neighbourhoods and houses with large trees are assumed to be better kept and protected than those without them.