Stories from the NFCCA Newsletter, the “Northwood News”

Northwood News ♦ June 2011

Second in a Series

How Trees Enhance Our Lives — In So Many Ways

By Carole Barth

Everyone knows that trees grace our lives with beauty.  “No town can fail of beauty, though its walks were gutters and its houses hovels, if venerable trees make magnificent colonnades along its streets.” —Henry Ward Beecher, Proverbs, 1887.  We admire the transformation from winter’s pared-down sculptural forms to the lush abundance of summer shade.  We look forward to the glad rags of autumn and the somber elegance of evergreens in winter.

If we take the time to get to know individual trees, we begin to appreciate their idiosyncratic beauty:  a zig-zagged trunk that tells of a deadly, slow-motion battle for sunshine; or a lacework wrought by generations of woodpeckers.  Like laugh lines on a beloved face, they simply deepen our definition of beauty.

But trees also enhance our lives in very practical ways.  They provide a wealth of ecosystem services.  While it’s impossible to put a price tag on services such as good health, clean air, and clean water, one can estimate the dollar value of some services such as:  pounds of pollution removed, reduced heating and cooling costs, amount of carbon sequestration, and so on.

According to TreeBaltimore, when you add these benefits together, it is not unreasonable to conclude that $57,000 in economic and environmental benefits is provided over the life of a single tree.  You can estimate the economic value of a tree in your yard or on your street for yourself with the tree calculator at www.trees.maryland .gov/calculator.asp.  [Note:  This calculator is no longer available.  This URL reroutes you to]

These services also include some you may not have considered.  You may not associate trees with stormwater management, but it turns out that one large tree can eliminate 5,000 gallons of stormwater runoff each year.  And while you may know that the net cooling effect of a healthy young tree equals 10 room-sized air conditioners operating 20 hours a day, you may not know that the shade can also significantly prolong paving life, thus lengthening the time between road repairs.

Of course, we all know that trees are important for wildlife, providing nesting space for birds and nectar, fruits, seeds, and nuts to feed many animals.  But did you know that Hackberry, Cottonwood, Hawthorn, Wild Cherry, Willow, Ash, Linden, River Birch, Eastern Red Cedar, Chokecherry, Flowering Dogwood, Holly, Musclewood, Locust, Sweetbay Magnolia, Maple, Pawpaw, Wild Plum, Redbud, Shadbush, Black Walnut, and Sassafras trees are all host plants for butterfly larvae?  Did you know that the first hummingbirds to arrive each spring depend on tree sap rather than flower nectar?

Trees also support wildlife that doesn’t live in or on the tree.  Without the carpet of fallen leaves, salamanders would have no winter home.  Without streamside trees, there is no woody debris to form in-stream habitat, no shade to protect stream life, and no food for the base of the fishes’ food chain.  Research in the Northwest has documented an additional link between forests and fish.  As expected, there are more salmon in well-forested streams.  Interestingly, forests also grow better where there are more salmon, because they get nutrients from the salmon coming upstream to spawn.

Like the relationship of trees and salmon, trees have provided special benefits to humans since time immemorial.  Farmers and watermen relied on practical phenology (the study of periodic biological phenomena, such as flowering, breeding, and migration, in relation to climatic conditions) to correctly schedule their work.  No matter how weather patterns shifted from year to year, the farmer knew it was time to plant corn when the leaves of the dogwood tree were the size of squirrel ears, and watermen knew the shad were running up the river whenever the shadbush tree was in blossom.

Today, we pay more attention to how trees provide other economic benefits.  According to appraisers, trees add seven to 25 percent of the total value of a particular property.  Homes adjacent to forests are priced eight to 20 percent higher, commercial rents increase seven percent.  Shoppers are even willing to pay nine to 12 percent more to shop in areas with trees.

Surprisingly, trees also contribute to crime prevention.  “Kuo and partners (2003) have found that the presence of trees within high-density neighborhoods lowers levels of fear, contributes to less violent and aggressive behavior, and encourages better neighbor relationships and better coping skills.” [What Could We Lose?  Economic Values of Urban Forest Benefits, Kathleen Wolf, University of Washington.]

A recent study in Portland, Ore., associated large trees with a reduction in crime.  Among the tree variables analyzed, canopy size of both street and yard trees and the number of trees growing on a lot had the most effect on crime occurrence.  The researchers reason that large trees signal to potential criminals that a neighborhood is better cared for and would, therefore, increase the likelihood they will be caught.

And, finally, scientists are beginning to document how trees and nature in general impact our mental and physical health.  School children with ADHD show fewer symptoms and girls show more academic self-discipline if they have access to natural settings [Faber Taylor et al., 2001].  Hospital patients recover more quickly and require fewer painkilling medications when having a view of nature, and passive views of nature are associated with reduced physiological stress response [Ulrich, 1986].  Office workers with a view of nature are more productive, report fewer illnesses, and have higher job satisfaction [Kaplan, 1993].

When you take all these benefits together, it seems clear that we should place much greater emphasis on planting and preserving trees.  As Teddy Roosevelt said in his 1907 Arbor Day message, “It is well that you should celebrate your Arbor Day thoughtfully, for within your lifetime the nation’s need of trees will become serious.  We of an older generation can get along with what we have, though with growing hardship; but in your full manhood and womanhood you will want what nature once so bountifully supplied and man so thoughtlessly destroyed; and because of that want you will reproach us, not for what we have used, but for what we have wasted.”

In the next installment of “Don’t Fear the Trees,” we will look at how trees continue to play a vital ecological role even after death.   ■

Part 1: Don’t Fear the Trees Part 3: Stumped About Stumps?

   © 2011 NFCCA  [Source:]