United States 

 Department of 

 Agriculture 



Forest Service 



Intermountain 

 Forest and Range 

 Experiment Station 

 Ogden, UT 84401 



Research Paper 

 INT-306 



January 1983 



Production and 

 Product Recovery 

 for Complete Tree 

 Utilization in the 

 Northern Rockies 



John M. Mandzak, Kelsey S. Milner, and John Host 



INTRODUCTION 



The harvest of small timber of commercial size has historically 

 been a problem due to relatively high logging costs per unit 

 coupled with low product values. Small logs are typically proc- 

 essed into studs (8-ft 2"x4", 2"x6", etc.). Because demand 

 and price constantly fluctuate, the process of harvesting and 

 conversion of small timber to studs is difficult and marginally 

 profitable. Nevertheless, small timber represents a relatively 

 large percentage of the volume of timber available in the Rocky 

 Mountain area, and this percentage will increase in the coming 

 decades as old-growth timber stands are converted to managed 

 stands. If costs of logging small trees were reduced, the ulti- 

 mate profitability of the production of framing material could 

 be improved dramatically. 



Stands of small timber are of two basic types. There is the 

 relatively old stand, with small-diameter trees that have little 

 potential for further net growth. Such stands occupy valuable 

 growing space yet contribute little to site productivity. Stagnant 

 old-growth lodgepole pine (Pinus contorta var. latifolia 

 Engelm.) and stands of true fir {Abies spp.) are common 

 examples. The harvesting and subsequent regeneration of these 

 stands, usually by clearcutting, would bring these areas back 

 into production. 



The second type of small-timber stand is the relatively young, 

 overstocked stand with some stems of small commercial size. 

 Partial cutting, such as a commercial thinning, would permit 

 added growth on the remaining stems and prevent the stagna- 

 tion of the first type of stand. Such partial cuts in young 

 ponderosa pine {Pinus ponderosa Dougl. ex Laws.) stands 

 would also help prevent buildup of bark beetle populations by 

 maintaining tree vigor. These young, overstocked stands are of 

 critical importance because a shortage of merchantable timber 

 is expected after the old-growth has been harvested. The faster 

 these young stands are brought to merchantable sizes, the 

 shorter will be the time interval with a lower harvesting rate. It 

 is, therefore, highly desirable that young stands are managed so 

 as to fully utilize the growth potential of the site. 



Management of small timber is also affected by the demand 

 for wood fiber suited to the manufacture of paper, fiberboard, 



particleboard, or hog fuel. Historically, mill trimmings and 

 waste have been the source of such material. However, during 

 slack market periods when lumber and veneer production is re- 

 duced, the supply of such waste material is also reduced. Small- 

 sized timber could help satisfy the raw material shortfall during 

 these intervals. 



This study was undertaken to explore one alternative for 

 utilizing postlogging residues and to determine the feasibility of 

 generating boiler fuel from thinning operations for the Forest 

 Service and Champion Timberlands, respectively. The study 

 took place during August 1980. It is one of a series of studies 

 dealing with utilizing material from thinning operations in 

 western Montana. 



Study Objectives 



The objective of this study was to test the feasibility of a 

 mechanical harvesting system designed to process small logs 

 and produce chips suitable for hog fuel and pulp and paper. 

 The logging system is shown schematically in figure 1 . Specific 

 goals were: 



1. Compare the productivity and advantages of falling and 

 prebunching turns for grapple skidders by a feller-buncher (tree 

 shear) relative to conventional sawyer falling, choker-skidding 

 logging methods. 



2. Compare the quality of logs manufactured by a tree 

 processor to that for logs produced by conventional methods. 

 Also, determine production rates for the tree processor. 



3. Compare the loading time for small logs delimbed and 

 bucked by a tree processor to those for logs decked in a con- 

 ventional system. 



4. Evaluate the tree processor-chipper logging system as a 

 forest management tool. Specific tasks to be considered 

 include: 



a. Thinning stands on a corpmercial basis. 



b. Clearing stands of small trees for regeneration on a 

 commercial basis. 



c. Reducing insect damage potential in ponderosa pine 

 stands. 



1 



