OPPORTUNITIES FOR INCREASING TIMBER SUPPLIES 



121 



sidered suitable for treatment they had to meet 

 certain requirements as follows: 



Treatment 



Commercial thin- 

 ning 

 Precommercial thin- 



Stand age 



Stocking 



Trees 

 per acre 



35-75 More than 70 



percent 

 15-25 More than 30 450 



ning percent 



Fertilization Stands qualifying for precommercial 



or commercial thinning 



For ponderosa pine and lodgepole pine stands, 

 the area classification shown in table 48 of Ap- 

 pendix I was evaluated on a judgment basis to 

 determine areas most suitable for management. 



Management Practices Considered 



For each of the areas selected as indicated 

 above, management regimes were evaluated to 

 determine practices and areas that would produce 

 at least 5 percent return on investments in 

 intensified management. These included: 



1. Westside conifer stands 



a. Commercial thinning of stands at ages 

 30 through 70 



b. Precommercial thinning of 15-year-old 

 stands, followed by commercial thinning 



c. Fertilization and commercial thinning 

 of stands of ages 30 through 70 



d. Precommercial thinning of 15-year-old 

 stands, followed with fertilization and 

 commercial thinning 



e. Conversion of hardwood stands to 

 Douglas-fir 



f. Planting of nonstocked areas following 

 harvest 



g. Planting of nonstocked areas with genet- 

 ically superior stock following harvest 



2. Ponderosa pine 



a. Commercial thinnings of small sawtimber 

 stands 



b. Precommercial thinnings of 15-year-old 

 and stagnated stands, followed with com- 

 mercial thinnings 



3. Lodgepole pine 



a. Precommercial thinning of 15-year-old 

 stands and stagnated stands, followed 

 with commercial thinnings. 



In some cases current management was limited 

 to protection from fire, insects, and disease. In 

 other cases significant areas were already being 

 treated according to these management prescrip- 

 tions. These acres already being treated were sub- 

 tracted in estimating areas available for manage- 

 ment intensification. 



Yield Assumptions 



The yield estimates used in this analysis in- 

 cluded data for expected harvests with 1970 levels 

 of management, and increases in harvests possible 

 with intensified management. These yield esti- 



mates were based upon available yield tables and 

 judgments of timber management research spe- 

 cialists. Allowances were made for anticipated 

 impacts of insects and diseases in both managed 

 and unmanaged stands. Estimated yields of west- 

 side conifers also were reduced to reflect discon- 

 tinuities in forest cover that exist within the com- 

 mercial forest land area. This reduction was 

 assumed to be 15 percent for all sites and areas. 

 Increases in future harvests were determined by 

 subtracting per-acre yields with ongoing programs 

 from per-acre yields with intensified management 

 and multiplying the increase by the appropriate 

 number of acres. For public owners it was also 

 assumed that allowable cut procedures will result 

 in scheduling harvests in approximate line with 

 increases in growth. This allowable cut effect was 

 used to portray harvest increases but was not 

 considered in calculating rate of return. The 

 harvest available from individual treated acres 

 was used in rate of return calculations. 



Cost Assumptions 



Costs of intensified management as of 1970 were 

 derived from a number of public and private 

 sources in the Pacific Northwest. Assumed per-acre 

 costs averaged as follows : 



a. Planting westside conifers following 

 harvest — $35 



b. Precommercial thinning — $50 



c. Commercial thinning (netted out of priced 



d. Fertilization— $22 



e. Site preparation for conversion of hardwood 

 stands less than 45 j^ears of age — $40 



Price Assumptions 



Two price assumptions were used in evaluation 

 of the increased yields obtainable with intensified 

 management — one based on National Forest 

 timber sales in 1970, with the second assuming a 

 steady rise to 2020 at a compound rate of 1.5 per- 

 cent annually in product prices, with 75 percent 

 of the increase going to stumpage. Data in terms of 

 Scribner log scale, primarily for old-growth timber, 

 were converted to prices for second-growth timber 

 in terms of International %-inch log rule. This 

 resulted in the following prices : 



1970 prices B020 prices 

 per MBF per MBF 



Westside conifer harvest cuts $23. 20 $97. 50 



Westside conifer thinnings 17. 90 92. 50 



Ponderosa pine 17.00 91.60 



Lodgepole pine 4.40 53.50 



Economic Analysis 



The estimates of yields, values, and costs 

 developed for selected areas where management 

 intensification appeared most promising were 

 used in developing estimates of areas that would 

 yield at least a 5-percent rate of return on mar- 

 ginal costs of intensification at both 1970 prices 



