Trees clean our air, water, and soil. They also add greatly to our health, sense of well being, quality of life, and our economic future in many ways. As a result, the presence of trees and healthy urban forests amounts to a healthier and more sustainable community.
We all breathe the same air and use the same water and soil to survive, therefore, it is important to understand how trees have a direct and profound effect on each of these vital resources as well as our future.
Tree planting and proper care offers an opportunity for each person or entity to mitigate (or offset) their personal environmental “footprint” due to the many benefits they offer. A few of these benefits include improved air and water quality, reduced energy use, reduced urban temperatures, reduced storm water runoff, and flooding, as well as increased property values among many other economic benefits.
Rising levels of carbon, specifically carbon dioxide (CO2), are accelerating global warming and our urban forest offers the opportunity to mitigate the problem by sequestering (or storing) carbon as well as ozone, nitrogen oxides, and sulfuric oxides plus filtering particulate pollution. Since the Dallas/Fort Worth area is in non-attainment with federal air quality standards, we need all the trees we can get, especially the large and old trees. USDA Forest Service research shows that larger trees provide 80% more benefits than small stature trees, or those recently planted.
As an urban forest declines in health or significant populations are lost over time, they must constantly be replaced to maintain the many benefits they provide. Failure to conserve trees or replant what was lost can cause many problems such as increased asthma patients, increased particulate matter, and a decrease in air quality. Poor air quality results in increased health care cost to treat the associated problems. Conservation is important because larger healthy trees (over 30 inches) sequester 90 times more carbon than smaller trees (under four inches) and store 1,000 times more carbon.
Reduced Energy Use
Planting deciduous trees on the west, south, and east exposure of homes and buildings (or strategic shading) can save up to 30% on our energy bills. If we can shade our air conditioners, we can save an additional 10% on our energy bills. By planting dense evergreen trees on the north side of a building or home to slow the cold winter winds, additional energy savings can be gained. By reducing energy use, we decrease emissions from regional power generation plants and their negative effect on our air quality.
Reduced Urban Temperatures
A 1995 geothermal study of the Dallas area by Dr. Ken Morgan with Texas Christian University, found that various areas could be ten to twelve degrees hotter than Oak Cliff due to the extensive tree canopy cover and minimal grey infrastructure. The grey infrastructure amounts to large amounts of brick, glass, and concrete that hold heat well into the night which increases urban temperatures—called the urban heat island effect (UHI).
By strategically placing trees in UHI problem areas such as parking lots and vast expanses of grey infrastructure, we reduce urban temperatures as well as evaporative emissions from the fuel tanks and fuel systems of our vehicles. Heated fuel tanks and fuel systems release hydrocarbons and 16% of all hydrocarbon emissions are created by evaporative emissions. By reducing urban temperatures, air quality improves because the formation of ozone is dependent on higher temperatures.
Reduced Storm Water Runoff and Flooding
Large amounts of grey infrastructure greatly increase the amount of storm water runoff which can lead to flooding. Trees reduce storm water runoff by allowing the rain to slowly filter through the foliage which decreases the potential for flooding. Strategic shading of grey infrastructure not only reduces flood potential and the UHI effect but it can also extend the life of asphalt by 60%. This offers a very large return on our investment in tree planting and care plus reduces the impact that asphalt has on the environment.
Improved Water Quality
Bioremediation or phytoremediation is the use of trees, plants, and biological agents to remove or neutralize contaminants in polluted water or soil. Leaves, twigs, and limbs that lay on the ground stimulate biological activity which also helps to remove pollution. Removing the organic layer on the top of the soil reduces its capacity to grow healthy plants and trees as well as its ability to remove various types of pollution.
Increased Economic Benefit
Trees offer many tangible economic benefits such as increased property values and a better quality of life which will attract corporations and the general public to an area. The result is an increased tax base due to the establishment of a more desirable area to live and conduct business. The more green and sustainable an area becomes in the future, the more successful it will become in economic terms.
Sprawl and “business as usual” will no longer be desirable because sustainable infill developments will attract the public. As far as a return on investment, for every dollar spent on tree planting and care, we receive up to five dollars in benefits according to research. Studies across the nation show that residential home prices can be up to 20% higher due to the presence of trees. Also, a home will sell faster with healthy trees as opposed to others with few or no trees.
There are a great number of other benefits that are well researched such as the reduction in stress associated with urban living, reduced crime rates, reduced noise pollution, reduced ADHD in children, increased test scores for students, increased habitat as well as food for wildlife, among others.
Ask not what trees can do for you, but rather…what you can do for trees!