By Christina Procopiou
In the 20th century, chestnut blight and Dutch elm disease decimated billions of U.S. trees growing in forests and lining urban and suburban streets. The tree diseases, caused by invasive pests—a wind borne fungus spore from Japan and a beetle from the Netherlands, respectively—changed the face of one American city landscape after another and cost local governments and homeowners a fortune.
Today, 63 percent of U.S. forestland, or 825 million acres, is at risk of increased damage from established pests like the emerald ash borer, hemlock wooly adelgid and others, according to the U.S. Forest Service. Urban and suburban trees are the costliest casualties. Removal and replanting are expensive, and loss of trees from streets, yards and parks hurts property values and robs communities of the benefits trees provide, such as cooling and improved air quality.
Those costs are not evenly distributed: Local governments tasked with tree removal and treatment pay 10 times more than the federal government does due to pest invasions. Homeowners who have to remove dead trees from their properties are stuck with $1 billion of the costs compared with the federal government’s $216 million and the timber industry’s $150 million burdens. That’s apart from the effect on homeowner property values, estimated at $1.5 billion per year. In total, established tree pests are costing Americans well over $2 billion a year, according to a paper published May 10 in the journal Ecological Applications.
