How Valuable Is Your Tree?

You probably have at least one tree that you really care about. The sight of it gives you pleasure, you appreciate the shade, the rustle of the leaves are soothing, looking at the tree might lower your blood pressure and you are sure it adds value to your property.

Now a free online tool, the National Tree Benefit Calculator, http:// www.treebenefits.com/calculator/, gives you an understanding of the environmental and economic value that your trees provide on an annual basis. Enter your zip code so that the tool can take into account your climatic conditions, select the species from a drop down list (you can choose from broadleaf, evergreen, conifer and small unknown if you don’t know the species) enter the diameter of the trunk at chest level and the land-use type of the location (single family residential, multifamily residential, commercial, etc). Given this information the Tree Benefit Calculator produces six pages of information specific to the tree species and size:

• Overall Benefits – A pie chart summarizes savings for stormwater, property value, electricity, natural gas, air quality and CO2. It also projects the savings of the tree whien it grows 5 more inches.

• Stormwater – How many gallons will this tree intercept in a year? A 24 inch white oak will reduce annual runoff by 7,970 gallons. Trees reduce runoff by:

• Intercepting and holding rain on leaves, branches and bark

• Increasing infiltration and storage of rainwater through the tree's root system

• Reducing soil erosion by slowing rainfall before it strikes the soil

• Property Value - Real estate agents have long known that trees can increase the "curb appeal" of properties thereby increasing sale prices. Research has verified this by showing that home buyers are willing to pay more for properties with trees. This model uses a treeʼs Leaf Surface Area (LSA) to determine increases in property values.

• Energy - Strategically placed trees can increase home energy efficiency. A 24 inch Southern Red Oak will conserve 229 Kilowatt / hours of electricity for cooling and reduce consumption of oil or natural gas by 7 therms each year.

• Air quality – A graph displays the value of 8 pollutants that this tree either absorbs or allows a reduction in production. We now know that the suburban trees can mitigate the health effects of pollution by:

• Absorbing pollutants like ozone, nitrogen dioxide and sulfur dioxide through leaves

• Intercepting particulate matter like dust, ash and smoke

• Releasing oxygen through photosynthesis

• Lowering air temperatures which reduces the production of ozone

• Reducing energy use and subsequent pollutant emissions from power plants

• CO2 - Trees sequester CO2 in their roots, trunks, stems and leaves while they grow, and in wood products after they are harvested. A 24 inch Red Maple will reduce atmospheric carbon by 1,052 pounds annually.

You can use this program to determine the best tree for your environmental need or simply to quantify the value of your favorite tree.

Carol Ivory, Loudoun County Master Gardener