Tongass National Forest

Timber Stand Improvement

Pruning

Pruning is the removal of branches to a certain height on the tree to increase the amount of clear wood (wood without knots), growing on the tree. Pruning is an accepted management tool for improving wood quality but it has not been a common practice in the Pacific Northwest or southeast Alaska because high quality old-growth timber has historically provided a steady supply of clear wood.

However, the amount of old-growth forests available for timber production has declined and a larger proportion of the timber base is expected to come from the lower quality young-growth forests.

The value of clear wood has also increased. Thinning and pruning activities are necessary to ensure the production of high quality clear wood in managed young-growth stands.

Pruning of branches to increase side lighting will also enhance understory forage production in young forest stands. The effect of thinning and pruning on the development of understory plants and conifers is being studied by the Adaptive Management Project on POW and an older experimental projects such as the pruning near Cave Creek, shown above.