Tongass National Forest

Timber Stand Improvement

Insect and Disease Monitoring

Lower insect and disease levels generally exist here as compared with many areas of the lower 48. However, insects, diseases and related decay processes are an integral part of forest ecosystems. Many play a key role in gap-level disturbances and provide for wildlife habitat in old-growth forests. One of our major concerns is the decline of yellow-cedar. Yellow-cedar trees are dying from unknown causes.

Normal levels (endemic) of insect and disease populations exist in all forest ecosystems. In traveling through the old growth forests of the Tongass, one can see evidence of rots and decays, rusts, cankers, aphids, sawfly, hemlock mistletoe and conditions such as cedar dieback. Populations tend to vary with weather patterns and management options. Hemlock sawfly has been monitored on hillsides in the forest.

The forest service produces an annual report on insect and disease monitoring. For information contact the USDA Forest Sciences lab in Juneau.