63% of U.S. trees are at risk from damaging imported pests. These pests cause billions of dollars in damages each year, and U.S. property owners and municipalities foot most of the bill. Efforts to prevent new pests are not keeping pace with escalating trade and must be strengthened if we are to slow the loss of our nation's trees. Dr. Gary Lovett of the Cary Institute of Ecosystem Studies describes the threat and the steps that can be taken to save our forests.