Tongass National Forest

Timber Stand Improvement

Young Forests

Young forests, sometimes called second-growth or young-growth forests, are mostly even-aged forests. For 50 years, the Tongass National Forest has used even-aged management by clearcutting to meet its Congressionally-mandated multiple use mission while sustaining the health of the forest ecosystem. Even-aged management through clear cutting has proven to be economical in many instances, fully-tested and effective in eliminating disease. It also reduces the risk of within-stand wind throw on widespread shallow soils and limits the wounding of on thin-barked species of Southeast Alaska .

Along with even-aged management, the Tongass National Forest applies timber management principles to enhance wildlife habitats. As these even-aged stands develop, there is a pressing need to apply silvicultural techniques to treat these young-growth stands in key wildlife habitats to retain understory forage plants that can be shaded out by dense canopies.

Background

The 1997 Tongass Land and Resource Management Plan Record of Decision estimated 80 percent of future harvest would be by even-aged management using the clearcut regeneration method.

The Forest Plan also includes a provision for establishing a forest young-growth management program to maintain, prolong and improve understory forage production and to increase future old-growth characteristics in young-growth timber stands for wildlife. Even-aged management sets the successional wheel in motion, creating the young-growth that follows.

With proper tending, new tree stands can produce twice the volume with less defect and more uniform size than the late seral forest they replace in just 90 to 120 years. At the close of fiscal year 2000, there were more than 400,000 Tongass National Forest acres, or 95 percent of all harvests, in an even-aged condition. Current habitat enhancement activities include pre-commercial thinning, commercial thinning, pruning, creating or enchancing canopy gaps into young-growth stands, deciduous tree planting and seeding of forage plants.

Understory development results, from various research and study projects, indicate that thinning treatments improve deer forage availability when compared to no thinnings. Recent monitoring of older second-growth stands (60 years old) with various treatments has shown promise that understory can be re-initiated even after decades of canopy closure. (See photos attached of understory development with and without pre-commercial thinning treatments.) Pruning studies have shown the same conclusions.

Current Situation

The Tongass National Forest is currently planning and carrying out actions which will help in the continued effective management of young-growth stands and wildlife habitats. These actions include:

• Increased cooperative management efforts with Native Corporations. Native Corporation harvests are often adjacent to National Forests. Current Tongass National Forest timber planning efforts consider adjacent ownerships.
• Additional funding for treatment of young-growth stands for all resource benefits, such as wood production, wildlife forage and stream woody debris.
• Working to increase external and internal customers' knowledge of even-aged management using an adaptive management process. This is a continuous 5-10 year process of action-based planning, monitoring, research, evaluation and adjustment to improve implementation and achieve desired management objectives.
• Developing a strategy to include beach, estuarine and old growth Land Use Designations (LUDs) to move the stand more quickly toward old growth characteristics. About 30 percent of the 400,000 acres of young-growth lie within non-development LUDs or are rendered unsuitable for timber management as a result of Forest-wide standards and guidelines.
• Developing and applying silvicultural techniques to treat existing older young-growth stands in key wildlife habitats to retain understory plants. Recent monitoring of older young-growth stands with various treatments has shown promise that understory can be re-initiated even after decades of canopy closure.
• Building of more sites demonstrating how young-growth can be managed to meet wildlife and timber needs. Pre-commerical thinning provides 10-plus years of deer forage. Pruning and inter-planting of alder also show promise as techniques to enhance understory in older young-growth.