Caring For The Urban Forest

Royal Roads urban forest in Victoria may be N. America's oldest

In recent years we have been increasingly recognizing the importance of trees and forests everywhere, including urban forests. Urban trees provide soul soothing green space amidst the black and greys of the endless pavement and concrete of cities around the world. When we build our cities, whenever possible, we also plant trees - and for very good reasons.

Why Are Urban Forests Valuable?

Trees and forests:

• Conserve energy by shading buildings and paved surfaces
• Filter air, and water-borne pollutants
• Remove atmospheric carbon dioxide, a potent greenhouse gas
• Reduce storm water runoff
• Increase the value of our homes
• Have important psychological benefits; seeing and being around trees makes us feel better
• Urban forests can be managed to provide wood and lumber for art, building, and a sustainable energy source

Studies have found that hospital patients with a view of trees recover faster and with fewer complications than patients without such a view. Considering their importance to us, we should all be urban forest rangers and do what we can to maintain the health of our trees.

Caring For Urban Trees

Urban trees are constantly under threat. Changes in soil depth around trees can harm root systems as it drastically reduces the amount of oxygen and water available. Urban development often includes excavating - digging around established trees can damage fragile root systems, and kill trees.

Basic Care

Tree problems also occur because of over and under watering, improper fertilization, and competition between roots. Over watering causes the soil pore (air) spaces to fill with water and restrict available oxygen. Under watering does not provide sufficient water for proper development. Over fertilization can injure or kill the roots, while under fertilization results in a lack of the minerals essential to maintain a healthy tree.

Competition for water and minerals between tree roots, bushes, grass and flowers can
stress trees. Trees will stress if routine soil preparation for flowers damages tree roots.

Top 10 Urban Forests

Other practices that affect tree health are: deicing salts and other chemicals; wounding through digging and trenching; and adding deep mulch over 13 cm ( 5 inches), concrete, pavement, or compacted soil that restricts water percolation, and suffocates roots.

Herbicide Alert - Imprelis Kills Trees

Another potential problem is the improper application of a herbicide, or using the wrong herbicide (or any herbicide). Poison pusher conglomerate Dupont is in the news lately because of its new herbicide Imprelis. This herbicide was developed to target broad leaf weeds in grass, but it seems to be killing much, much more than that.

Imprelis is killing Spruce, Pine, and other urban conifer trees after the correct application of the herbicide on surrounding lawns. Dupont is being sued by a number of landscapers, towns, golf courses and cemeteries that say that label use of their product has inadvertently killed tens of thousands of trees across America.

Imprelis is so persistent that grass clippings are basically toxic waste for several months after application of the herbicide. Dupont recommends that grass clipping not be composted or sent to the landfill during that period.

We can help our urban forests through proper basic care of our trees. Another way we can help is by pushing for a ban on the cosmetic use of harsh landscaping chemicals in our cities. We need to get our lawns and gardens off chemicals so that not only our urban forests can thrive, but so that all life that is found within them can thrive, naturally.