Benefits of Trees
The environmental, social, health, and financial benefits of urban trees has been thoroughly studied. The benefits of trees go far beyond their emotional or "subjective" value, which in itself is significant. It seems the more you know about the actual benefits of trees, the less likely you are to allow them to be needlessly destroyed during development. The following links provide substantial scientific information about the value of urban trees.
Op-Ed From the New York Times - Clear-Cutting the Truth About Trees (12/20/2009, By BERND HEINRICH)
- THE Copenhagen climate-change summit meeting is behind us, and did not achieve what was hoped for. There was no lack of good intentions, but they generated conflicts rather than solutions, and the product was a weak agreement to disagree in the future. Forests were part of the discussion, and several things were understood: carbon dioxide is a potentially world-altering lethal pollutant, fossil fuels are the problem, biofuels are part of the solution. But exactly how to pare down the use of fossil fuels and switch to energy sources derived from plant material? That is the problem. [more...]
Letter to the Clackamas County Board of County Commissioners
This letter summarizes some of the research that CC Urban Green has found that clearly illustrates the real-world value of trees in our urban environment. We feel that every administrator and planner who has a role in decisions that affect the tree canopy should read and understand this information.
- Letter to the BCC
Human Health - Landscape and Human Health Laboratory
The Landscape and Human Health Laboratory at the University of Illinois at Urbana-champaign is a multidisciplinary research laboratory dedicated to studying the connection between greenery and human health, including cutting-edge research on the health benefits of trees. To read about their findings, go to http://www.lhhl.uiuc.edu.
Financial and Social - USDA Forest Service
The US Department of Agriculture Forest Service Research and Development (FS R&D) is the world's largest forestry research organization. FS R&D conducts ecological and social science research to understand ecosystems, how humans influence those systems, and how to manage for sustained and enhanced benefits. It employs 524 scientists, as well as several hundred technical and support personnel, located at 65 sites throughout the United States.
One of the best products of the USDA Forest Service is the Western Washington and Oregon Community Tree Guide. This document provides authoritative support for the value of mature urban trees. From the introduction:
"Western Washington and Oregon communities can promote energy efficiency
through tree planting and stewardship programs that strategically locate trees
to save energy, mitigate urban heat islands, and minimize conflicts with powerlines and other aspects of the urban infrastructure. These same trees can
provide additional benefits by reducing stormwater runoff, improving local
air, soil, and water quality, reducing atmospheric carbon dioxide (CO2), providing wildlife habitat, increasing property values, enhancing community
attractiveness and investment, and promoting human health and well-being."
Summary of the Benefits of Trees
- Trees are broadly held as being among Oregon citizen's most cherished values. Trees work for you non-stop. They are an important part of community infrastructure and vital to our personal and environmental health. They are a legacy we plant and leave for many generations – impacting our city with a better quality of life, a better business climate, and an enhanced sense of place.
Did you know trees do all that? – plus they are fun to climb!
Trees help us clean the air. Tree leaves absorb dirty air and remove pollutants. Particulate pollution like dust is deposited on the leaves. Plus, trees absorb carbon dioxide and produce oxygen for us to breathe.
Trees cool the air by releasing moisture into the air through a process
If we can preserve our neighborhood trees, as well as plant and nurture more trees throughout the North Clackamas County area, they will help to improve our current air quality, with all the health benefits and our own small part in mitigating the threat of global climate change.
- 100 trees remove five tons of CO2 per year
- 100 trees remove about 1000 lbs of pollutants per year, including:
- 400 lbs of ozone
- 300 lbs of particulates
Trees help clean our water by holding rainfall on the leaves and branches, making the threats of flooding less likely. The tree roots hold soil in place so that it is not washed away in severe storms. Water is cleaned as it passes through the roots and into the groundwater. And we can save water on irrigation when there is a tree shading the lawns that we water.
- 100 mature trees catch about 250,000 gallons of rainwater per year
- Decrease polluted runoff
- Decrease soil and hill erosion
Trees save energy by shading buildings and minimizing the need for air conditioning in the hot summer months. This energy saving is particularly important because the shade helps reduce peak energy consumption at the hottest time of the day. In addition to direct shade on buildings, trees cool entire neighborhoods by releasing moisture into the air and shading surfaces like parking lots and streets that hold heat in the sun. In the winter, trees can help reduce heating costs by buffering the wind.
- Save up to 30% of annual cooling costs
- Save 10-25% of energy used for heating
- An additional 1 million trees strategically planted could save $10 million in energy savings.
Houses in tree lined neighborhoods sell for a premium in Clackamas County. The trees give the neighborhoods a sense of place, a community where neighbors know one another, and slow traffic as drivers sense the enclosed space in these tree tunnels.
- Each large front yard tree adds 1% to sales price
- Large specimen trees can add 10%, or more, to property values.
Studies have shown that trees are good for business. Shoppers will search for that one shaded parking spot on hot summer days, and shops located in cool shopping districts see the influence of trees by
- More frequent shopping
- Longer shopping trips
- Shoppers spend more for parking
- Shoppers spend 12% more for goods
Social and Psychological Benefits
Studies show that trees help us humans feel peaceful and secure as they bring a bit of nature into our urban environments. Community trees are vital to community health.
- Trees reduce levels of domestic violence and foster safer, more sociable neighborhood environments (Sullivan and Kuo, 1996).
- Views of nature reduce the stress response of both body and mind when stressors of urban conditions are present (Parsons et. al., 1998).
- Trees (along with other plants) absorb high-frequency noise which is the most distressing frequency range for humans (Miller, 1997).
- Hospital patients that see trees need less medication and have faster recovery times following surgery (Ulrich, 1985).
Trees bring people together, where neighborhoods are made stronger by the shady streets and parks. Trees cast shade in the evenings that encourages residents to come out and enjoy walks and bike rides in their neighborhoods. Trees slow drivers as they make them feel enclosed in the tree tunnels. Neighborhood tree plantings are events that neighbors join in to get to know each other and form new relationships. In these ways, trees are bringing people together!
Essential Habitat For Many Species
The tree canopy is essential for sustaining a viable ecosystem for birds, small animals, and the rest of the web of life that surrounds us. These creatures also have a right to survive. As the science of ecology informs us, all creatures depend on a balanced ecosystem for survival. For true sustainability, we must protect the habitats of these creatures. Overly large houses on tiny, denuded lots are detrimental to all living things.
Take Action To Preserve Your Tree Canopy
- You can get involved! Pledge your support of the Urban Green Tree Conservation Ordinance today. How? By sending an email to CC Urban Green and express your view (click HERE to send an automated email). We are collecting as many signatures as we can to make visible our desire to preserve our urban tree canopy.