Add planting a tree to your new year’s resolutions

“The best time to plant a tree was 20 years ago. The second best time is now.” — Chinese proverb

Have you ever walked from bright sunlight into the full shade of the woods? On all but the most humid days, it feels as though someone turned on the A/C.

It can be 10-25 degrees cooler in the shade of a tree than in full sun. Moisture added to the air as the tree transpires increases this cooling effect. Some researchers have found even more dramatic temperature reductions. Properly sited shade trees can reduce electric bills and carbon dioxide emissions.

In the northern hemisphere, deciduous shade trees sited to the south and west of buildings provide shade from the heat of the day in summer. When leaves drop in fall, they allow the sun to shine through, providing savings on heating costs. Evergreen trees planted as windbreaks on the west side of a building can reduce heating costs by 25 percent.

The ecological benefits provided by large shade trees do not stop there. They improve air quality by absorbing pollutants such as ozone and nitrogen dioxide. They also intercept particulate matter from industrial emissions, smoke, dust and pollen. Trees sequester carbon dioxide by fixing carbon during photosynthesis and storing it as biomass. While younger, very actively growing trees have higher sequestration rates, roughly half the dried weight of a tree is carbon, and so a big shade tree is keeping a lot of carbon tied up.

A big concern for many urban areas is stormwater mitigation. Like many older cities, the greater Pittsburgh area is under a consent decree to stop combined sewer overflows into our three rivers. The danger of these overflows to drinking water and recreational users is substantial. In addition, storm events often cause localized flooding that results in property damage and even fatalities. Engineered or “gray” solutions are going to be very expensive for everyone, and green infrastructure is one way to make those costs more affordable.

Some communities have already enacted stormwater fees to help pay for upgrades to outdated sewage systems, and this trend is expected to grow. Residential and commercial property owners can get a break on these fees in many cases if they install green infrastructure or take other steps to reduce impervious surfaces on their property.

Trees are big part of the solution because they intercept rainfall with their foliage and branches, slowing its fall so that it has a chance to be absorbed by the soil. When rain falls on impervious surfaces, it runs off rapidly, causing erosion and carrying pollutants and sediment into our waterways. Trees protect and improve water quality by filtering stormwater and absorbing it with their root systems. The bigger the tree, the bigger the benefits in terms of managing stormwater.

Properly sited and well-maintained trees – especially large shade trees – can increase the sale price of otherwise identical houses by an average of 5 percent. Many studies correlate shorter hospital stays, reduced stress and lower crime rates with tree-lined streets and properties.

Trees also provide habitat for wildlife, from songbirds to squirrels. In addition, they support a diverse community of insects, many of which are beneficial and help keep insect pests in check. Insects are also an important food source for baby songbirds; even those that eat fruits and seeds as adults depend on the protein from insects when they are young.

Trees offer beauty with flowers, attractive foliage that often explodes in a riot of color in fall, and many have attractive fruit or bark that offers winter interest. Plant a tree and reap the rewards!

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