What Are The Threats to Urban Trees?
| Friday, April 17, 2015
Many people take trees for granted, but they add so much value and beauty to their surroundings, whether rural or urban. A neighborhood with established trees is much more welcoming and feels far more settled than a new subdivision on cleared land. People who plant trees in their communities report feeling more invested in them and more willing to work together to solve other issues. Trees also have a positive environmental impact: they reduce erosion, help to minimize run off water, absorb noise, and filter air pollution. They also control solar radiation, moderate temperature, and help keep both indoor and outdoor climate more pleasant.
For all of the above reasons and perhaps more, the City of Grand Rapids has partnered with Friends of Grand Rapids Parks on an urban forest project. Its goal is a 40% tree canopy within the city limits. In the last three years, the Grand Rapids Urban Forest Project has planted almost 400 trees and hosted over 50 tree-centric events per year. This, of course, does not include the trees planted by individual citizens voluntarily on their own property.
Unfortunately, urban trees face stresses and pressures in the city that they would not if they were planted in a more rural environment. Under more natural circumstances, trees propagate in places that are more conducive to their growth and development. The leaves they shed in the fall provide both organic matter and a natural mulch for them come spring. Stands of trees take the blows of high winds together - and survive them better. Tree seedlings that find themselves in naturally inhospitable environments do not grow to reach adulthood. They die out for lack of water, nutrients, or sun.
When people plant trees in the city, they either do not know or they forget the challenges trees face. They are often more concerned with planting trees where they will be pretty or personally useful rather than where they will grow best. The soil in urban environments tends to be more compacted. Temperatures fluctuate more in the city. Asphalt and cement work to absorb and hold heat and flush water away before trees can properly absorb it. Water, air, and soil are polluted at more concentrated levels, and both natural and introduced pests find it easier to overwhelm an urban environment. It's just harder to be a tree in the city.
Because there are so many threats to the health of urban trees, anyone wishing to plant or maintain trees in the city should work to become aware of them and form strategies to minimize their impact on those trees. Whether this means adding mulch and fertilizing on a schedule, watering more during dry periods, or carefully evaluating a location prior to planting there, an ounce of prevention is worth a pound of cure.
So be kind and thoughtful to those city trees, and they will flourish and reward you in ways you can't even imagine later.