Tree Improvement as a Strategy for Coping with Invasions

Scott Schlarbaum

University of Tennessee, Department of Forestry, Wildlife & Fisheries

Knoxville, Tennessee

The Tennessee forest is predominantly upland forest dominated by Oak-Hickory (71%). About 80% of this forest is non-industrial, privately owned land while about 8% is privately owned by the forestry industry.

The tree improvement program of the University of Tennessee has traditionally served the needs of the timber and Christmas tree industry, and has now added a wildlife component. Many tree improvement programs at the land grant universities have died out. In dealing with plant pests, if you can't control them, you're back to plant breeding, so much more work is needed on this issue.

Regarding the American Chestnut blight in the 1930s that came through Tennessee and wiped out this species, Schlarbaum thinks it can be restored to some degree but money is needed and time is of the essence. Most of gene pool has already been lost and the rest is going quickly.

Regarding frazier fur and red spruce in Smoky Mountain National Park, balsam woolly adelgia moved into the area in 1958, feeding on frazier fur and killing it. It cannot be controlled on a large scale. A soapy spray can kill the adelgia on a specific tree but doesn't control the overall problem. With an aggressive breeding and testing program started in the 1950s, it would have been possible to have trees that were 75% frazier fur that were resistant to adelgia, but it wasn't done.

Butternut canker has killed most of the butternut trees in the Smoky Mountain National Park. Dogwood anthracnos disease is a big problem and funds are needed for breeding programs, seed collection, etc. Gypsy moths are hitting the oak population. Hemlock are threatened by woolly adelgia, and this problem is moving into North Carolina now.

Recent insect diversity studies reveal that over 20% were Asian oak weevil. These insects eat the roots of oak trees and are very destructive to seedlings. What can be done? There is quite a bit of monitoring going on, but more funding is needed for research into solutions.

The western white pine breeding program was successful and rust- resistant trees have now been introduced back into the system.