CONTENTS Page Introduction ........................................... I Background ........................................... 1 Log-making ........................................... 2 Preparation ......................................... 2 Tree-to-Tree Travel ................................... 3 Felling ............................................. 3 Lirnbing ............................................ 6 Bucking ............................................ 6 bppit~g............................................ 6 All Cot~iponents...................................... 7 Yarding .............................................. 7 Preparation ......................................... 8 Outbound Travel ..................................... 8 Choker-Setting ....................................... 8 Skidding ........................................... 9 Unhooking ....................................... 9 All Components ...................................... II Surnrnary ............................................. 11 Literature Cited ........................................ 12 PHILIP M. McDONALD is doing research on silviculture of Sierra Nevada forest types, with headquarters at Redding, Calif. A native of Seattle, Washington, he holds bachelor's (Washington State University, 1960) and master's (Duke University, 1961) degrees in forestry. ntense competition and narrow profit margins Station began a long-term study in 1962 of logging Iare forcing land managers, foresters, and logging production rates on its Challenge Experimental supervisors to become increasingly conscious of Forest, Yuba County, California.' The most abun- logging costs. Tax assessors are similarly concerned dant species there is ponderosa pine (Pinus potderosa with costs as a basis for setting tax rates. At the same Laws.). Dominant ponderosa pines average 140 leet time, good silviculture and environmental protection tall at 100 years (Arvanitis, et a[. 1964). Next most often require that marginal or submarginal trees and abundant is Douglas-fir (Pseudotsuga menziesii logs be removed from the forest. But data on logging [Mirb.] Franco). Found in lesser amounts are white cost and production are singularly scant-particularly fir (Abies concolor [Cord. & Glend.] Lend].), sugar for young-growth stands. In the Western United pine (Pinus lambertiana Doug].), and incense-cedar States, data on such stands on high-quality sites are (Libocedrus decurrens Torr.). especially important. These sites would be the first to be intensively managed because on them the most This paper reports results from a study ol young- fiber can be grown in the shortest time. In California, growth stands on highquality sites. Objectives of the logging production data are needed because many study were to quantify various components of log- young-growth stands are now of merchantable size. making and yarding production and to examine the Indeed, as Oswald (1970) points out, "in some areas relationships among these components and the effect of the State, harvesting activities on private land are of species. The results are applicable to about 1.5 shifting into young-growth stands." million acres of highly productive timberland on the To help fill the need for such information, the lower west slope of California's north central Sierra Pacific Southwest Forest and Range Experiment Nevada. BACKGROUND Stand age was about 95 years at the time of study. and group-selection cutting methods (McDonald, et Commonly, about 30 overstory trees per acre are al. 1969). Production rates were independent of greater than 20 inches in b~eastheight diameter cutting method in general. (d.b.h.). Beneath these trees are the more shade toler- In this study, six compartments averaging 38 acres ant Douglas-fir, white fir, incense-cedar and hard- each were partially cut from April to August 1962. woods. I-tere 12- to 20-inch d.b.h. trees number about Leave trees larger than 20 inches d.b.h. numbered 45 per acre; those 3.5 to 12 inches d.b.h. about 200 from 2 to 20 and averaged about 7 per acre. Cutting per acre. The basal area of all trees 3.5 inches in removed 28 to 78 percent of the merchantable vol- diameter and larger is about 240 square feet per acre. ume, meaning that trees down to 12 inches d.b.h. These basal areas and numbers of stems are typical of were removed. The nunimum log size measured 10 young-growth stands on high-quality sites and are feet long and 10 inches in diameter inside bark part of the logging production picture. (d.i.b.) at the small end. Long logs (32 feet) were Elsewhere in dense young-growth stands, Csiz- desired and cut whenever possible. mazia and McIntosh (1964) found that limbing was In addition to being heavily forested, the study the factor affecting log-making production most. For compartments were generally similar, having rolling yarding production, choker-setting was most critical. topography, maximum slopes of 25 percent, and little I11 several studies (Csizmazia and McIntosh 1964; surface rock. Amount of cull and brush (other than Hasel 1946; King 1963; Worthington 1966), either small trees) was minimal. Altogether, tlus was a log-making or yarding production rates or both were "good" logging chance as young-growth chances go inversely related to log size-and significantly so. (fig. 1). Previous work in young-growth, mixed-conifer stands at Challenge has shown that log-making and ' U.S. Forest Service research at the Challenge Experimental yarding production rates do not differ appreciably Forest is conduct4 in cooperation with the Soper-Whecler among the seed-tree, single-tree-selection, clearcut, Company, Strawberry Valley, Calif. Figure ?-The 95-year-old stand before logging. The large number of trees with their many dead branches is typical of young-growth stands on high-quality sites in north central California. LOG-MAKING The fallers were experienced at the11 trade and pa~dat a gyppo rate. They worked as two-man "sets" Preporation -set members staying well w~thinearshot of each f 1 other, but each man l~mbedand bucked each tree I Between-tree travel that he had felled. -n During the production study, fallers never knew i--"- which of them were to be timed or what day timing :..,,. , ,sb2;s..s,.;.2:~~::,,: .,: ; would take place. These selections were random. A forestry-trained observer timed functions by stop Limbing, . .,, . .>., ., . .. watch to the nearest 0.1 minute. Different compo- ,,, ,,,,<,?,;.>><3><,~3<.,:1 nents were (1) preparation time, (2) tree-to-Cree 6ucki;lg travel, (3) felling, (4) limbing, (5) bucking, and (6) lopprng branches from tree tops. T~nungbegan when L~~~~~~ the falle~sarrived at the landlne each mornlne and r I I I I ended when they returned to it Ln the evening.-~lto- ~~~ ~ I gether, timing was performed on 191 trees of <differ- 0 10 20 30 40 ent species and took slightly over 8 full days. Pro- Percent of total log-making time duction averaged 22,740 board feet Scribner Scale Figure 2-Preparation time is an important per man-day. Other recorded data included individual component of log-making production. log diarileters, lengths, and pertinent remarks. Preparation (rest, eat, drink) and mechanical needs (fuel, adjust, Because of rigorous physical and safety demands, and sharpen saw) were the largest categories as the ,'..d preparation time always is high (fig. 2). Human needs following breakdown shows: / !.- Portro~zof preparation rrme Tree-to-Tree Travel (percetrtj This component was minimal because the trees Itcrn' File and adjust saw 12.1 to be cut grew relatively close together. Over-all, Fuel saw 11.6 tree-to-tree travel had a negligible effect on produc- Scout 5.3 tion and amounted to only 0.9 minutes per thou- Rest 31.0 sand board feet. Drink and lunch 26.6 Fell snags 6.0 Walk to and from land~ng -7.4 Felling In felling, size of tree is important. The larger the tree, the greater its height, and the more time and skill necessary to fell it with minimun~damage Altogether, preparation time amounted to 8 minutes to the residual stand. To avoid damage, some trees per thousand board feet. were wedged. Occasionally, a small tree or some Limbing - - - Incense-cedar - - 7 V, a, .% 2 c -- 5 - - LE Moderately shade- e tolerant conifers I I I I I 0 I I I I I 2 25 I I I I I I I I I I 0 i Bucking Lopping L a, - - 2 20 - - - I I I I O12 1; 20 25 30 35 4012 15 20 25 30 35 40 Diameter breast height (inches) Figure 3-Lag-making production rater relative to tree diameters. Species differ ences are readily seen. SKIDDING After felling, limbing often is the next step in logging a young-growth stand. "Walking the log" minimizes the effect of the brushy understory. Bucking is usually done at the same time as limbing, but the two activities were performed separately in the study to facilitate timing. Yarding begins and ends at the landing. This one is typical in size and shape. About 39 percent of the skidding in this logging operation was adverse but on gentle grades such as this. The average turn consisted of 4.6 logs. Unhooking a five-log turn may be slow since the hooking apparatus has a greater chance to lodge against or beneath the logs. UNHOOKING brush near the base of a study tree had to be cut survive in the understory. Those that do survive before felling could commence. In such cases, brush- have small crowns and few branches. For these,,. , ing time was included in the felling. When brushing limbing production rates are high. Larger ponderosi or wedging was necessary, felling time often was pines, however, carry numerous dead branches and excessive.