The American Chestnut Tree (Castanea Dentata) is a case study for what can go very wrong when an exotic pest gets loose. In the early part of the 20th Century a fungal pest (Chestnut blight) decimated the once prominent tree, with long lasting effects on our landscape and wildlife. Today scientists are making significant progress in developing trees which are resistant to the blight. This through traditional breeding techniques and more recently with genetic manipulation. We talk today with Tim Phelps of the Tennessee Division of Forestry about the Chestnut and about other forest health issues.