Intermediate treatments such as precommercial 

 thinning, weeding, pruning, and release of desirable 

 trees early in the life of overcrowded stands would 

 have major impacts on timber values. Such treat- 

 ments do not produce immediately usable wood, but 

 have a payoff in faster growth of residual trees, 

 shorter rotations, higher quality wood, and increased 

 resistance to insects and disease. 



There are large areas of overcrowded stands of 

 merchantable size trees. Numerous research studies 

 have indicated that cutting of some merchantable 

 trees to improve spacing and stimulate growth (com- 

 mercial thinning) can provide early returns, utilize 

 material otherwise lost as mortality, and concentrate 

 growth on the more valuable trees. 



Accelerated harvest of old-growth stands on the 

 National Forests in the West. — Increases in timber 

 harvests above sustained yield levels in the old growth 

 timber stands on the National Forests in the West 

 could temporarily increase the volume of timber 

 available for harvest. This course, which has been 

 proposed by some members of the timber industries, 

 some timber-dependent communities, and other asso- 

 ciated interests, could offset for a time the expected 

 decline in the harvest of timber from forest industry 

 ownerships in the Pacific Northwest. However, har- 

 vests above the sustained yield level could not be 

 maintained with present and planned management 

 programs and the dependent industries and com- 

 munities would sooner or later be faced with a drop 

 in harvests. For this and other reasons, chiefly the 

 impacts on the natural environment, accelerated 

 harvest has been strongly opposed by environmental 

 and preservation groups and many other nontimber 

 groups interested in the management and use of the 

 National Forests. Thus the rate of harvest on old- 

 growth stands is a policy issue of wide interest — it is 

 discussed further in an accompanying technical docu- 

 ment, "A Recommended Renewable Resource Pro- 

 gram"— 1980 update." 



Fertilization. — The use of fertilizers to accelerate 

 and improve tree growth has been increasing in recent 

 years. Most of this activity has been in the Pacific 

 Northwest and in the South — practically all by 

 industrial owners. Experience to date suggests that 

 timber yields can be increased from 5 to 20 percent 

 with applications of the proper fertilizers on nutrient 

 deficient soils. 



"U.S. Department of Agriculture. Forest Service. A recom- 

 mended renewable resources program — 1980 update. For Serv. 

 Series FS-346. 540 p. plus appendixes. 1980. 



Large areas of naturally regenerated forests are overcrowded. This 

 increases mortality and the time required to produce merchantable 

 wood. 



Drainage and irrigation are other enhancement 

 actions that have been used in forestry for many 

 years. On some sites, water control is the most impor- 

 tant action for the establishment of trees for timber 

 production. 



Harvest practices. — Numerous studies have shown 

 that an important way to increase future timber 

 growth is to use harvest practices that return the 

 leaves and small branches to the soil. This material 

 contains relatively large amounts of nutrients that 

 support the next generation of trees. In addition, this 

 material reduces surface erosion and contributes to 

 maintaining soil structure. Harvest practices should 

 also be designed to minimize damage to residual trees 

 and reduce the volume of unmerchantable tops of 

 trees and defective trees left on the ground as logging 

 residues. 



Research. — Much can be done to increase timber 

 growth through more effective use of existing tech- 

 nology. Investments in intensified management could 

 be made more effective by expanding the technologi- 

 cal base for such efforts. More information is needed 

 about the responses of forest stands of different types, 

 ages, and sites to intermediate treatments such as 

 thinning. Better knowledge of spacing control in pre- 

 commercial thinning and subsequent intermediate 

 cutting could help increase output of both timber and 

 nontimber values. Before the most effective tree fer- 

 tilization can be achieved, more knowledge must be 



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