Who Says Money Doesn't Grow on Trees?
Most of us tend to think more about trees in the spring and fall when the seasons change. In spring we eagerly await the emergence of tender green leaves; in fall we luxuriate in the visual banquet of oranges, yellows and reds.

Trees deliver measurable, tangible benefits that can result in long-term savings for homeowners and whole neighborhoods. Trees reduce air pollution, conserve water, reduce soil erosion, save energy, reduce noise pollution, screen objectionable views, create wildlife habitat, and increase property values.

In addition, trees provide many psychological benefits. They provide privacy and a sense of solitude and security. They often serve as a bridge to history and many are planted as memorials to loved ones. Some people feel an almost religious connection to trees. And studies have shown that looking at trees and other vegetation can slow the heartbeat, lower blood pressure and result in a more relaxed brain pattern.

In a 1985 study, the American Forestry Association concluded that a single 50-year-old urban tree would supply air conditioning worth $73, soil erosion and storm-water control worth $75, wildlife shelter worth another $75 and air pollution control valued at $50. Total value in 1985 dollars was $273. Total value during the tree's lifetime, compounded at five percent for 50 years, equals $57,151. That's not including the five to 20 percent higher property value of a landscaped home.

Just how do trees provide us with these benefits? First, trees act as a carbon sink, removing the carbon from carbon dioxide (CO2) in the atmosphere and storing it as cellulose in the trunk. At the same time, trees release oxygen back into the air. The trees on one acre produce enough oxygen for 18 people every day.

Strategically placed trees can be as effective as other energy-saving home improvements like insulation and weather-tight windows and doors. Deciduous trees, which shed their leaves in winter, can provide shade and block heat from the sun during summer months. In winter, they admit sunlight for warming. These trees should be planted on the south and west sides of buildings. Plant "solar friendly" trees with open crowns that drop their leaves in early fall and leaf out again in early spring. Examples are ash, maple and poplar.

Evergreens, which keep their needles all year, can serve as windbreaks that save 10 to 50 percent of the energy used for home heating. Plant evergreens on the north side of your home to intercept and slow down winter winds.

In addition, the leaves, twigs and branches of trees and shrubs absorb sound. Trees not only help to control noise pollution, they add their own soothing sounds when wind rustles through leaves and branches. Tree roots help hold the soil in place, reducing soil erosion. The channels created by roots help increase water infiltration.

Especially when planted in groups, trees add significantly to the diversity of birds and animals in an area. They add color, sound and movement to the landscape and are greatly enjoyed by people.

In urban neighborhoods, getting residents together to clean up and landscape the area can even reduce crime. In one UNH Cooperative Extension project, after volunteers and residents of Manchester's Cedar Street spruced up their neighborhood and planted trees, the number of calls to police fell in a single year from more than 800 to only 64.

Given all the benefits that trees can deliver, doesn't it make sense to plant one, two-- or a few-- this spring?

By Margaret Hagen, Agricultural Resources Educator 5/2/07
Posted May 11, 2007