|Photo by Marvin Shaouni|
It isn't easy being a tree in the city.
The average lifespan of an urban tree is just 20 percent what it would be in the wild. For every tree that's planted in Detroit, four are lost. A number of stressors contribute to this high mortality rate: compacted soil, nutrient deficiencies, and greater susceptibility to pests. Improper pruning doesn't help matters, and neither do the wounds inflicted by people and machines.
But we need trees in the city, and for more reasons than the obvious ones. Sure, we need them to take our carbon dioxide and give us back oxygen, to provide cooling shade, and to play their part in complex urban ecosystems. Yet a growing body of research suggests that we need them for much more than that. Trees absorb stormwater, helping reduce runoff. They clean the soil. They promote economic vitality, raising property values and subtly encouraging shoppers to spend more time spending money. They reduce our stress levels and might even help reduce violent crime. (Readers ready to dig into some of the research supporting these claims -- and a host of others related to the benefits of trees -- will appreciate this handy resource list.)
None of this is news to the folks at the Greening of Detroit, a nonprofit working to grow a greener, leafier city since 1989. And while the Greening is well-known for its work promoting, planting, and caring for trees, it remains what Rebecca Salminen Witt, president of the Greening of Detroit, calls "an organization on the move" and is continually finding new ways to support a more sustainable Detroit.