Fahey, Thomas D.; Cahill, James M.; Snellgrove, Thomas A.; Heath, Linda S. 1991.Lumber and veneer recovery from intensively managed young-growth Douglas-fir. Res. Pap. PNW-RP-437. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 25 p.The objective of the study was to develop models that predict lumber and veneer recovery as a function of young-growth log characteristics. Empirical lumber and veneer recovery data for logs cut from more than 300 young-growth Douglas-fir trees were used in model development. Trees were sampled from 15 stands in western Oregon and Washington and represent a wide range of growing conditions, sites, ages, and stocking history. Models were developed that predict (1) the volume recovery of primary (lumber and veneer) and secondary (chips, sawdust, and peeler cores) products, (2) lumber grade recovery based on machine stress-rated rules, (3) lumber grade recovery based on visual grading rules, and (4) veneer grade recovery. Log characteristics investigated were log diameter, the proportion of juvenile wood present in the log, log taper, and limb size. Lumber degrade caused by warping of juvenile wood was evaluated for low temperature, low humidity, kiln schedule. SummaryEmpirical recovery data were used to develop models predicting lumber and veneer volume and grade recovery for young-growth Douglas-fir logs. The effect of juvenile wood on lumber degrade due to warp also was evaluated. More than 300 trees were sampled from 15 stands in western Oregon and Washington. These stands reflected a wide range of growing conditions, sites, ages, and stocking history. Saw logs were sawn into" nominal 2-by 4-inch and 2-by 6-inch lumber; lumber was kiln dried, surfaced, and graded by using visual and machine stress rated (MSR) lumber grades. Veneer logs were peeled into nominal 1/8-inch full sheets, half sheets, and random width veneer. The proportion of log volume recovered as rough green lumber differed with log diameter and log taper. Lumber recovery increased with log diameter and decreased as taper increased: log diameter had the most impact. The proportion of log volume recovered in green veneer differed with log diameter and the average diameter of the largest limb in each log quadrant (LLAD). Recovery increased with diameter and decreased as LLAD increased. Lumber grade recovery, based on the visual grading rules, varied by LLAD; recovery in the higher grades dropped off dramatically as LLAD increased. Recovery of MSR lumber differed with LLAD and the amount of juvenile wood in the log; recovery in the higher MSR grades decreased as LLAD and the percentage of juvenile wood increased. Juvenile wood was defined as the proportion of log volume between the pith and the 20th annual ring. Veneer grade recovery dropped off as LLAD increased. Lumber degrade caused by warp during kiln drying was almost nonexistent in this sample of lumber. Only 70 boards out of over 7,000 were degraded because of warp.

Fahey, Thomas D.; Snellgrove, Thomas A.; Plank, Marlin E. Changes in product recovery between live and dead lodgepole pine: a compendium. Res. Pap. PNW-353. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station; 1986. 25 p. Six studies were used to compare differences in recovery of volume and value among live, recent dead, and older dead lodgepole pine (Pinus contorts Dougl. ex Loud.) in the Western United States. The products studied included boards, random-length dimension, studs, and veneer. For the average size log (12 cubic feet) absolute values were highest for boards, followed by dimension, veneer, and studs for both live and dead timber. The percentage change in value from live to dead, however, showed the reverse order; studs lost the least value and boards the most.

Relationships between tree traits and tree value for lumber production were investigated. For the purposes of estimating relative economic weights for use in multitrait selection in coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii), tree height, diameter at breast height, and branch diameter were measured on 164 trees (ages 36-66 years). Increment cores from a subsample (92) of these trees were assayed by X-ray densitometry to determine wood density. Bole volume was derived by summing the log volumes of all logs from each tree. Value of lumber recovered from each tree was determined in a separate mill study using both visual and machine stress rated (MSR) grading rules. Multiple linear regression was used to relate tree value to the growth and wood quality traits. Stem volume and branch diameter significantly influenced tree value under visual grading, with relative economic weights of 0.06dm3 and -5.22cm, respectively. Wood density significantly influenced tree value under MSR grading (relative economic weights: 0.06dm3, -6.69cm, and 0.06kg/mdm3, respectively), where lumber strength is measured more accurately. These regression coefficients can be used directly as economic weights in selection indices.

This report summarizes the results of lumber recovery studies at four sawmills in western Oregon and western Washington; two dimension mills, one grade mill, and one timber mill were included. Results from individual mills are reported and discussed. The four mills were also combined to approximate "average" conversion of logs to lumber for the region. Recovery information is presented by diameter and log grade for lumber volume, lumber grade, and lumber and log value.

Veneer was produced from 768 blocks cut from secondgrowth Douglas-fir from the Coast Ranges in northwestern Oregon. Timber was selected from a variety of stand ages and conditions. The recovery ratio was higher and the veneer grade lower for blocks peeled into 1/6-inch than for 1/10-inch veneer. Densely grown stands had a much higher veneer grade recovery than open grown stands, with no loss in recovery ratios. Block and log data are given in Scribner scale and gross cubic volume.