As we near Earth Day 2012 it is important that
we all realize that the planting of 1 tree can make a difference.
Read more about How trees change our life
The information provided is in reference to urban forests, but these benefits and values also apply to rural forests.
Canopy, or tree canopy, is a term used to describe the leaves and branches of a tree or group of trees. In an urban forest, tree canopy is important to the potential benefits the forest may provide. In general, the more area it covers and the denser the canopy, the more benefits the trees can provide. Although one tree is better than none, 100 are better still. Whether the benefits are from one tree or many trees, they are all still real and most can be quantified in some way. Often, forest benefits are divided into three categories: social, economic, and ecologic. It is difficult to divide the benefits that the urban forest canopy provides into these categories because so many benefits fall into more than one.
Social Benefits
Just as with a rural forest, an urban forest provides many benefits. Numerous studies have been done about the social
and psychological benefits of “green” in urban environments. The findings of the studies make a strong case for the
importance of urban forests. Urban public housing residents who lived in buildings without trees and grass nearby were
asked about how they cope with major life issues. They reported more procrastination and assessed their issues as more
severe than residents with green nearby.
A study done with children with Attention Deficit Disorder (ADD) found that children with ADD were better able to focus
and concentrate after playing in natural, green settings, than in settings where concrete was predominant.
Apartment buildings with high levels of greenery have been shown to have approximately half the number of crimes
than those with little or no greenery. The results proved true for both property crimes and violent crimes. A similar study
found that residents living in areas without nearby nature reported more aggression and violence than those living with
nearby green. In addition to these specific studies, access to nature also provides humans with other social benefits.
Parks and other green spaces provide a space for people to play, walk, jog, birdwatch, or just sit quietly. These activities
are good for our physical health in a society that is increasingly sedentary. It is also good for our mental health by
providing a place to unwind. Trees also reduce noise levels.
Economic Benefits
The economic benefits of urban forests are increasingly being documented. Economics often becomes the language
used when it comes to urban forest management. Budgets of municipalities must cover an array of services, and the
benefits of an urban ecosystem must often be proven to secure funding. In a study that considered the costs and
benefits of municipal forests in five U.S. cities, the researchers found that for every dollar spent on trees, the benefits
returned were worth from $1.37 to $3.09. A little math tells us this is clearly a good investment.
Trees save money through reduced energy costs. Cities create what is referred to as a heat island. The concrete, asphalt,
buildings, and other surfaces absorb and hold heat from the sun. During hot summer days, cities can be five to nine
degrees warmer than surrounding areas. Shading, evapotranspiration, and wind speed reduction provided by trees help
conserve energy in buildings. A study conducted in Minneapolis, Minnesota, showed that trees placed in the proper
location can reduce total heating and cooling costs by eight percent.
Homeowners not only reduce costs of heating and cooling their homes, but increase the value of their property by
planting trees. Research suggests that property value can increase three to seven percent when trees are present. Trees
also make homes and neighborhoods more desirable places to live. One economic benefit that urban trees can provide,
but often don’t, is one based on products. Municipalities and tree services across the country have come up with ways
to use the wood that is cut from an urban forest. Products range from specialty furniture, to musical instruments, to
lumber for park shelters, to artwork. The income from selling products from the wood of trees being removed could be used to defray the cost associated with the removal, making trees an even better investment.
Trees and Climate Change
The information about how trees impact climate change is taken from the National Arbor Day website
http://www.arborday.org/globalwarming/treesHelp.cfm, and the American Forest Foundation website
www.americanforests.org/resources/climatechange/
Deciduous trees, planted on the west, east and south sides, will keep your house cool in the summer and let the sun
warm your home in the winter, reducing energy use.
Just three trees, properly placed around a house, can save up to 30% of energy use.
Trees or shrubs planted to shade air conditioners help cool a building more efficiently, using less electricity. A unit
operating in the shade uses as much as 10% less electricity than the same one operating in the sun.
Neighborhoods with well-shaded streets can be up to 6–10° F cooler than neighborhoods without street trees, reducing
the heat-island effect, and reducing energy needs.
Shaded parking lots keep automobiles cooler, reducing emissions from fuel tanks and engines, and helping reduce the
heat-island effect in communities.
Trees absorb carbon dioxide (CO2), the primary gas causing global climate change. Trees retain the carbon (C) from the
CO2 molecule and release oxygen (O2) into the atmosphere. The retained carbon makes up half the dry weight of a tree.
Forests are the world's second largest carbon reservoirs (oceans are the largest). Unlike oceans, however, we can grow
new forests. One acre of forestland will sequester between 150 - 200 tons of CO2 in its first 40 years.
