Trees play vital role in health of a city

By Larry Figart
Jacksonville, FL (September 25, 2009)- If asked “why are trees valuable?” many of us would reply that they are pretty, or that they give us shade and oxygen. Some may say that they provide lumber or paper. All those statements are true; city trees quietly provide us with many benefits that are very important in today’s urban environment. Trees have been providing an economic stimulus package for our communities long before it became a government priority.


Let’s begin with the some of the more well-known benefits.
* Trees can increase the value of property. A yard with large healthy trees growing in it has greater curb appeal than a yard with no trees. A healthy landscape that includes trees can increase property value by 10 percent to 20 percent.
* Trees can help us save energy. According to the U.S. Department of Agriculture, the net cooling effect of a young, healthy tree is equivalent to 10 room-size air conditioners operating 20 hours a day. The placement of trees in the landscape is important as well. The warmest part of the day in the summer occurs between 1 and 3 p.m. when the sun is in the southwest sky. A tree planted on the southwest side of a home will help to shade it during the hottest part of the day, thereby reducing our air- conditioning costs. Not only does this save us money in energy costs, but it also reduces the strain on the electric grid during the time of peak energy use.
* Trees can also attract patrons and increase visitation to retail businesses. This was highlighted in a survey of one Southern community conducted by Kathleen Wolf, where it was found that the public preferred to patronize commercial establishments and spend up to 12 percent more where those structures and parking lots were beautified with trees and other landscaping.
Urban forests save money
With the recent attention on the city of Jacksonville’s budget, it may be of interest that the urban forest saves us tax dollars. In Jacksonville, we get a lot of rain. The runoff from rainfall is stored in retention ponds so it can be slowed down and treated before it gets to the St. Johns River.
Our urban trees serve as mini retention ponds by helping to control runoff as the rain falls by intercepting and holding rain on leaves, branches and bark, increasing infiltration and storage of rainwater through the tree’s root system and reducing soil erosion by slowing rainfall before it strikes the soil.
In a 2002 study by American Forests, it was determined that Jacksonville’s urban trees provide stormwater storage of 928 million cubic feet. Without these trees, the cost of building stormwater retention ponds and other infrastructure to handle the increase in stormwater runoff would be valued at $1.86 billion .
More benefits from trees
Jacksonville’s urban trees are helping to fight climate change by reducing the amount of carbon dioxide in the atmosphere. For instance using the National Tree Benefit Calculator (www.treebenefits.com/calculator, a 12-inch diameter maple tree can lock up 278 pounds of carbon by storing it in its branches, trunk and roots. Trees also help to prevent the addition of carbon dioxide into our atmosphere by reducing emissions from power plants.
In Jacksonville, trees sequester 69,000 total pounds of carbon a year. This carbon storage may not solve the climate change issue, but it shows that trees can be a part of the solution. Trees have little openings in their leaves called stomata. These stomata allow for air exchange within the leaf. These stomata filter air pollutants out of the air. The air pollutants intercepted by trees include sulfur dioxide, nitrogen dioxide, ash, dust, and smoke particles.
Besides filtering out air pollution, trees provide us with oxygen as a by-product of photosynthesis. The same 12-inch diameter red maple example provides $3.12 of benefit by improving air quality. With diseases such as asthma, respiratory disease, heart disease all being made worse by air pollution, trees provide valuable health benefits by improving our air quality.
Finally, trees provide value as a great investment. There are not many investment opportunities where you can expect a 450 percent return on your money. Jacksonville’s urban trees provide just that. In a 2007 study commissioned by the city of Jacksonville, using the U.S. Forest Service I-Tree software, the Davey Resource Group determined that for every dollar invested in tree planting by the city, there was a $4.51 return in benefits from storm water retention, energy conservation, cleaner air and increased property values.
Our urban forest is more than just pretty trees. The services they provide are invaluable. There are opportunities in Jacksonville for you to get involved in our urban forest. They include planting more trees in your own landscape, volunteering for tree plantings at your local school or park, or becoming a voice for trees by joining a tree advocacy group.
By taking the value of trees into consideration, we all can contribute to the quality of life in Jacksonville. Larry Figart is an urban forestry extension agent with the Duval County Extension Service and the University of Florida/IFAS.
Related Resources:
Jacksonville Times Union- Trees play vital role in health of a city