There’s an old saying that goes, "Every day is Earth Day for a forester." This might be a bit of a stretch, but certainly the benefits derived from the wise use and management of trees and forests, all the things that foresters promote through forest stewardship, make earth a better place.
It is with this backdrop that I sound an alarm for invasive pests that threaten our forests. Asian long-horned beetle, hemlock wooly adelgid, and perhaps the most destructive, emerald ash borer, are non-native insects that have the potential to change the makeup and functions of our forests. Let’s look at the impacts from emerald ash borer (EAB).
It is estimated that there are over 160 million ash trees in Vermont; it is one of the ten most common trees of our forests. All ash species native to Vermont (green, white and black) have no known resistance to attack by EAB.
Unless treated with insecticides, most trees infested by EAB will die within 3 to 5 years. Experience in Michigan and other states has shown that once EAB is detected in an area, the impacts spread quickly and loss of ash trees increases rapidly over a few short years. So far, EAB has not been detected in Vermont, but has been detected in all states and provinces surrounding Vermont.
You may ask, why worry? It’s just one species of tree. Ash is an important component of the northern hardwood forest and a number of other wetland and upland natural communities. Millions of these important trees can be found in our woodlots and along our rivers and streams. Ash was widely used to replace the stately elms that graced our communities and were decimated by Dutch elm disease in the middle of the 20th century, and have historically been a favorite choice for street trees in Vermont due to fast growth and salt tolerance. A 12-inch ash tree provides an estimated $131 annually in benefits by filtering air pollutants, mitigating stormwater runoff, sequestering carbon, conserving energy and increasing property values. Ash trees are a valuable resource for wood (baseball bats, tool handles, firewood, black ash baskets), for wildlife, for water quality, for shade and beauty. Losses to the ash products industry in the eastern U.S. alone are estimated at $25 billion. Lastly, results from a recent study published in the American Journal of Preventative Medicine suggest that loss of trees to EAB increased human mortality related to cardiovascular and lower-respiratory-tract illness. This finding adds to significant existing evidence that the natural environment provides major public health benefits.
With partners including the federal government, the Agency of Agriculture, Food and Markets, and the University of Vermont, we have developed an action plan for the inevitable detection of EAB. If we find it early and slow the spread, we may have more management options. Individual high-value shade trees can be saved by treating them with insecticides, but they have to be treated before they are attacked. We have a management method for slowing the spread of EAB but it is only effective on early/small infestations. Eighty percent of new EAB infestations originate in or around campgrounds. A "Don’t Move Firewood" campaign encourages campers to "buy it where you burn it." If we can slow the spread of EAB and ash mortality, we can buy time for research to provide us with more options for managing EAB. Bio-controls have been released in several states, but results are still to be determined. Researchers are also investigating host resistance in ash species native to EAB’s home range.
So, given the harmful impacts from EAB, what can you do? The Department along with our many partners will be celebrating Ash Tree Awareness Week from April 27 to May 3, 2014. Many local events will be occurring around the state and a list can be found at vtinvasives.org. The key is to be observant. Check out the www.vtinvasives.org website to learn the signs and symptoms of EAB. Look out and look up at your trees and tell us if you see something. We and earth will appreciate it.
Steven Sinclair is Director of Forests for Vermont Department of Forests, Parks and Recreation.