How valuable is Akronís Signal Tree?
Even a tree-care professional had trouble coming up with an answer.
When Gordon Matthews, Akron-area district manager with the Davey Tree Expert Co., set out to quantify the benefits of the fabled tree in preparation for todayís observance of Arbor Day, he ran into a problem. The online calculator he was using wasnít designed for trees as massive as the 300-plus-year-old bur oak in Akronís Cascade Valley Metro Park, a tree believed to have served as a landmark that guided Native Americans on an important transportation route.
Besides, the calculator considered only a limited set of factors. Who can put a value on the contribution of such a tree to a cityís history or its residentsí collective pride?
Still, Matthews gave it a go.
By entering some data into the online calculator, he determined that the biggest bur oak he could calculate ó one with a trunk thatís 50 inches around, measured 4Ĺ feet above the ground ó would provide at least $344 worth of benefits a year. That figure is based on the treeís ability to absorb 1,021 pounds of carbon dioxide, which might otherwise add to the greenhouse gases in the Earthís atmosphere, and drink up 7,239 gallons of storm water, which might contribute to erosion or carried pollutants to a nearby body of water.
Since the Signal Treeís girth is more than twice that size, its actual benefits would probably be considerably higher. Matthews measured the treeís circumference at 127 inches, a figure he arrived at by combining the diameters of the trunk and the two main branches that angle outward from its base ó branches that were believed to have been shaped by Native Americans when the tree was just a sapling.
His purpose in coming up with a dollar figure was to draw attention to the ways well-chosen, properly maintained trees improve our properties, our communities and our sense of well-being. He had intended to put a tag on the tree listing its benefits, but he said the Summit County Metro Parks discouraged that because it didnít want to give people the impression that itís OK to post signs on its trees. So Gordonís tagging of the tree was only a symbolic act.
Some of the benefits of trees can be translated into dollars, he said, such as their ability to reduce air conditioning costs by producing shade or cut heating bills by shielding a house from winter winds. Healthy, mature trees also increase property values by an average of 10 percent, the United States Department of Agriculture says.
Other advantages arenít so easily quantified. Trees absorb pollutants, produce oxygen, clean the soil and muffle noise, a fact sheet supplied by Matthews noted. They also have psychological benefits, such as calming people and giving them a sense of security.
Neighborhoods benefit from the presence of trees, too. Studies show trees encourage people to spend time outdoors and congregate with their neighbors, deterring crime. And motorists tend to drive more slowly on tree-lined streets, research shows.
Thatís not to say trees come without costs. The Signal Tree, for one, underwent almost $7,000 worth of shoring up in 2003 after a couple of storms claimed two of its main limbs and now depends on cables to help support its aging structure.
Most trees donít require such expensive upkeep, of course, and statistics indicate the cost that goes into maintaining a tree pays off. Street trees planted by communities, for example, usually return 100 percent to 500 percent of the money spent on tree care in the form of carbon sequestration and reductions in energy use, storm water runoff and air pollution, according to Why Trees Matter, a program of the Ohio State University Extension.
How much are your own trees worth? You can get an estimate using the National Tree Benefit Calculator (www.treebenefits.com/calculator). For each tree, youíll need to know the species and the treeís diameter at 4Ĺ feet above the ground.
Mary Beth Breckenridge can be reached at 330-996-3756 or email@example.com. You can also become a fan on Facebook at http://tinyurl.com/mbbreck, follow her on Twitter @MBBreckABJ and read her blog at www.ohio.com/blogs/mary-beth.