Trees Offer More Than Shade

July 25, 2009 - Like a natural cathedral, the sycamores of Thompson Street in northeast Des Moines tower above you. The setting reminds me of a neighborhood in Venice, Calif., famous for its bungalows with fronts facing large, shared sidewalks and accessed by alleys from behind. To me, Thompson Street is even better, and apparently owes its unique qualities to a visionary planner back in the 1940s. Residents live in a green oasis just a block off busy East 14th Street.

The street is unusually wide, and designed in somewhat of a crescent shape. Native sycamores were planted between the street and sidewalk, and then alternated on the front lawns. Now that the trees are mature, the result is majestic. We need to showcase examples like Thompson Street to inspire more tree-lined streets and shaded, protected neighborhoods. Large mature trees like these are worth our investment, both public and private.

I first heard about Thompson Street from an enthusiastic Trees Forever member, who was surprised that I had never been there. After visiting, I asked several Des Moines tree experts about it, and I received responses like, "Oh sure, I know about those." I asked, "Why aren't you talking about this spot? It is a treasure and great example of urban planning - it should be in the textbooks like the Venice neighborhood."

There is a growing body of research that shows tree-canopied neighborhoods are good for both our mental and physical health. They encourage us to get outside more and slow down while driving. For me, I felt a sense of happiness and well-being and wanted to linger. The street is park-like, and I am sure many people would go out of their way to walk or run in this type of neighborhood.

There are lots of beautiful sycamores in Des Moines, including the more famous ones on Polk Boulevard. If you happen to live in that neighborhood, you probably think your sycamores are the most beautiful in the city.

Some consider sycamores to be a "trashy" tree, as they often drop small twigs and round seed pods. They also have huge leaves and do require some raking in the fall. But I hope you agree with me that the end result is worth the effort. Interestingly, it turns out that the sycamore is also one of the highest producers of environmental benefits.

Based on data from a tree assessment done here in Iowa by Trees Forever, the sycamore is a giant at improving air quality, providing energy savings and sequestering carbon. Did you know that one large, mature sycamore or oak can provide over $80,000 in public benefits over its lifetime? In terms of energy savings, carbon sequestration and other environmental benefits, choosing a large shade tree like an oak, maple or sycamore provides a lot more of these benefits than planting a smaller ornamental tree.

Today, experts recommend planting a diversity of tree species for shade. In many of our Iowa communities ash trees have been over-planted, and often make up around 30 percent of the overall tree canopy. This means that over one-fourth of the state's tree population is threatened by the arrival of the Emerald Ash Borer - making it even more important to protect and care for our existing mature trees that provide us with significant public benefits, especially during the summer months.

As concerned citizens we need to work harder to protect our urban trees by supporting ordinances that protect mature trees and allow for trees in the parking areas between the sidewalk and street. We need to encourage our city councils to increase city funding for tree planting and care of our public trees. And we must remember to select appropriate species as we plant and care for trees at our residences and on private and public lands. Remember, trees add to our quality of life every day.