WORK FORCE TRAINING NEEDS: AN EXAMPLE STUDY ON TIMBER VALUE RECOVERY IN SOUTH AFRICA

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1 WORK FORCE TRAINING NEEDS: AN EXAMPLE STUDY ON TIMBER VALUE RECOVERY IN SOUTH AFRICA Steven Kewley, B.Sc. (Forestry) Hon. Workstudy Officer, Mondi Forests Pietermaritzburg, South Africa Loren Kellogg, Ph.D. Professor, Forest Engineering, Oregon State University Corvallis, Oregon USA ABSTRACT -- The South African forest industry targets improved resource utilization through better timber value recovery, proper planning, and worker training. In the Mpumalanga province, we compared value recovery for felling by conventional chainsaws versus mechanical feller-bunchers for two species Pinus elliottii and P. taeda. Although mean volume recoveries did not differ significantly, felling with the feller-buncher yielded 2.4% higher recovery than with chainsaws. Using mechanical feller-bunchers also resulted in 6.8% higher tree value recovery. This increase was attributed to lower stump heights, decreased breakage, and improved sawlog recovery. Confidence was lacking in the use of simple directional felling devices, such as wedges and tree levers. Further operator training for both chainsaw and mechanical feller-buncher operations also is required. Particular attention must be given to improving felling practices that reduce tree breakage and increase resource utilization. Our experiences can be applied to broader workforce training needs and directions in the South African forestry sector. INTRODUCTION The South African forest industry arose from afforestation efforts that began 60 to 70 years ago. Plantations were established in such higher rainfall areas as the eastern coastal belt. Today, approximately 1.5 million ha of commercial pine and eucalyptus plantations comprise 1.3% of the total land area. The forest industry is dynamic, consistently among the top economic growth sectors over the last 20 years. As one of the countrys major export performers, it is becoming a world-class competitor, an industry that has consistently enhanced its financial viability through improved productivity. As seen from timber harvesting studies throughout the world, tree breakage during felling can result in significant forest value loss (Nixon, 1955; Zaremba, 1976; Guimier, 1980; Murphy & Gaskin, 1982; Murphy, 1982 and 1984; Murphy et al., 1991; Wirz, 1990; Warkotsch, 1993 & 1994; Fraser et al. 1997). Standing timber has potential value only; the real value depends on the volume and grades of timber that can be obtained during careful and efficient harvesting operations (Conway, 1968). Felling damage reduces the number of available log options. This is particularly important at the high-valued butt end of the tree, where poor felling technique can result in major losses from slabbing and splitting (Murphy et al. 1991). Unnecessarily high stumps also can reduce the amount of high-value, knotfree wood (Anon, 1942; Warkotsch, 1994). Economically viable and practical means for decreasing tree breakage must be identified. Minimum breakage should be a major objective in timber felling operations, along with operator training that emphasizes the need to work carefully. This will increase utilization of the available resources and maximize returns on investments for forestry enterprises. Although chainsaw felling is a common harvest method in South Africa, higher levels of mechanized harvesting systems are being introduced. Felling aids (wedges, levers, jacks, or line-pulling) are not typically utilized and felling is often done in haphazard directions. This can result in high levels of breakage and reduced extraction productivity. Suitable felling aids as well as worker training and monitoring for the use of correct and safe techniques are necessary. Expensive modern equipment, e.g., feller-bunchers and single-grip harvesters, also requires carefully selected and trained operators (Warkotsch, 1988). Workforce training is a significant forestry issue in South Africa that will affect growth and development of the industry in the new millennium. This paper reports a comparison study of felling with conventional chainsaws and mechanical fellerbunchers. Two pine species (Pinus elliottii and P. taeda) are commercially grown softwood sawtimber that are particularly susceptible to breakage in South Africa. The field study was designed to specifically compare timber value recovery because this factor most affects monetary returns to the forestry enterprise. STUDY AREA AND METHODS The study was conducted in September and October of 1998, on SAFCOLs (South African Forestry Company Ltd.) Wilgeboom plantation, Mpumalanga province (Figure 1). Stand details for the two compartments selected as most representative are found in Table 1. Three methods of felling were considered: 1. Mechanical feller-buncher felling: trees felled in the direction most suitable for aiding extraction and reducing timber breakage. Trees were CWFI 3506 FDC 302 1

2 bunched for grapple-skidder extraction. 2. Conventional chainsaw felling: trees felled in the direction the operator determined most suitable. No directional felling aids were used. 3. Directional chainsaw felling, with the aid of directional felling levers or wedges. For mechanical felling, a Timbco T445B fellerbuncher was equipped with an 84-cm bar and a chain felling head that included a four-bar link for felling downhill. Its leveling capabilities allowed it to operate on slopes up to approximately 45%. Trees were felled and placed in Stand Characteristics bunches for collection by a grapple skidder. The Timbco operator had three years experience on the machine; previously, he was a skidder operator. The manual portion of the study utilized a Stihl 040 chainsaw. The operator had six years of experience. Felling Method 3 was not completed because felling aids were not available on the plantation, and knowledge was lacking for their proper use by both chainsaw operators and forest management personnel. Although operators attempted to reduce breakage, normal logging production conditions prevailed and felling times were restricted. Compartment 1 2 Area (ha) Species Pinus elliottii Pinus taeda Age (yrs.) Mean DBH (cm) Mean tree vol. (m 3 ) Mean annual increment (m 3 /ha/yr) Stems per ha Ground slope moderate (25-27%) moderate (24-26%) Ground roughness 1 class 1 (smooth) class 1 (smooth) Undergrowth severe moderate 1 South Africa Terrain classification (Erasmus, 1994). Trials were laid out in a randomized block design, with one block per compartment. Within each block, treatments were replicated in five plots of 10 trees each. Each tree was numbered and breast height marked with white paint. DBH (130 cm above the ground) then was measured. Each operator felled five strip plots randomly in both blocks (50 trees per block). These plots represented the normal felling patterns used when clearfelling a compartment. All felled trees were scaled and measured in a particular plot after they were de-branched and topped, but before they were extracted. The recorded data included tree number, distance from DBH mark to base of tree after felling, butt diameter, number of logs, log class, log length, small-end diameter, amount of breakage in utilizable timber (>9 cm tree diameter), and bole diameter at breaks. Log-class characteristics are shown in Table 2. Timber value recovery represented the monetary value of the logs that theoretically could be manufactured from the felled stems, prior to their extraction. Value recovery was affected by the occurrence of breakage. The amount, extent, and the position of the breakage also affected the number of logs that could be bucked from a tree. Log volumes (m 3 ) for each tree were based on log lengths and small-end diameters, as measured off the marked tree stem. Values were then calculated for each log, using the calculated log volumes and the recorded log classes (Kewley, 1999). Because it was directly related to tree volume and log classes that could be bucked from a stem, diameter directly affected CWFI 3506 FDC 302 2

3 Table 2. Sawtimber and pulpwood log classes. Log class Product Length (m) Dia. inside bark (cm) Price ($/m 3 ) D1 Veneer 2.55 > C1 Veneer D2 Saw timber 4 > C2 Saw timber B2 Saw timber Pulpwood 2.4 > ($/ton) the value recovery from the felled trees. Therefore, it was used as a covariant. Timber loss due to stump height was calculated using the effective stump height, i.e., the length of tree stem that remained below the butt-log cut. This represented the amount of timber that was lost due to both stump height and butt-log end-cutting. SAS (Statistical Analysis Systems) software was used to run a GLM (General Linear Models) procedure to analyze timber value recovery, volume recovery, and stump height. The level of significance was 95% (p = 0.05). An analysis of covariance compared tree value recovery among felling methods and species. The GLM procedure was used to adjust the mean tree values in relation to their DBH (covariants) so they could be compared by felling method. Volume recovery comparisons between the two felling methods were analyzed with the same process. An analysis of variance was run to compare the effective stump heights between felling methods and compartments (species). This ANOVA included the effects of compartment, felling method, and the interaction between compartment and method. STUDY RESULTS Significant differences (p = 0.05) were found between stump heights in the two compartments and between felling methods. However, no statistically significant interaction was seen between felling method and compartment for stump height. Mean stump height for chainsaw felling was 27.9 cm; 12.6 cm for the feller-buncher. Conventional chainsaw-felled trees had effective stump heights 121% higher than for trees felled mechanically. In comparing the two compartments (species difference) for both felling methods separately and simultaneously, the null hypothesis of equal adjusted mean value recoveries could not be rejected (p = 0.05), i.e., value recovery was not affected by species. When felling methods were compared, the null hypothesis of equal adjusted mean value recoveries was rejected (p = 0.05), indicating that the treatments had different effects. The value recoveries for the two felling methods differed significantly; mechanical feller-buncher felling yielded 6.8% higher tree value recovery than chainsaw felling. In contrast, the null hypothesis of equal adjusted mean volume recoveries was not rejected (p = 0.05). This indicated that the treatments had the same effects, with no significant difference between felling methods. Overall, feller-buncher felling yielded 2.4% higher volume recovery than chainsaw felling. Differences in value recovery could not be attributed to differences in volume recovery, but rather to characteristics of the breakage. The number of breaks per tree for each felling method is shown in Table 3. Likewise, trees not damaged during felling had maximum recovery of timber. A single incidence of breakage within a tree automatically decreased its useful volume, thereby reducing further tree value optimization options. A second break had an additional negative effect. Position of the breaks also affected value recovery by limiting log-making options. The number of breaks per small-end diameter class is shown in Table 4. Chainsaw operations caused 13% more breakage in the sawlog-class diameters (>20 cm) than did the feller-buncher. This had a large impact on value recovery because of the higher value of the sawlogs. First, the potential tree length that could be utilized for sawlogs was reduced. Second, length specifications (4 m) sometimes made the timber length insufficient for obtaining a sawlog from the last section of the tree. Therefore, the log scaler had to produce a lower-value pulpwood log from that section, which resulted in lower overall tree value. DISCUSSION The variation in effective stump height between the two compartments was not explained by tree species. Physically, the trees were similar and neither species had excessive buttressing that affected stump height. Compartment 1, however, did have thicker undergrowth than in Compartment CWFI 3506 FDC 302 3

4 2. This factor influenced both felling operations, so that actual stump heights were higher in Compartment 1. In addition, effective stump heights were lower with fellerbuncher felling, for two reasons. First, by using the fellerbuncher felling head, the operator could sever the tree closer to the ground than with a chainsaw. Likewise, the thick undergrowth somewhat obstructed the chainsaw operator during felling. Second, a portion of the tree butt was wasted because of damage from the chainsaw-felling cuts. All the chainsaw-felled trees had uneven butts due to the scarf that was cut to guide the direction of the tree fall. Because the butt was not cut level, a piece of the tree butt (sloven) had to be removed in order to square off the butt before logs could be produced. Butt damage also occurred from chainsaw felling due to draw wood caused by a large uncut section (hinge) left to guide the tree when it was felled. Table 3. Number of breaks per tree, by felling method. Breaks per tree Chainsaw (%) Feller-buncher (%) None One Two 15 6 Total Table 4. Number of breaks per diameter class, by felling method. Diameter class Chainsaw Feller-buncher Breaks % Breaks % 9-19 cm cm cm Total Average break diameter (cm) Timber breakage resulted from a trees impact with the ground; felling across timber already on the ground (breakage to both the tree being felled and/or to those already on the ground); felling trees into standing timber; and the feller-buncher operator handling the trees after they had been cut but before they had fallen. In the feller-buncher operation, felling direction ranged from up-slope to traversing the slope. Trees were severed and moved into the correct position to fall. The feller-buncher head partially lowered the trees before dropping them, thereby reducing their impact with the ground. In contrast, the chainsaw operator had little control over the direction of fall, particularly with the larger-diameter trees and in the absence of directional felling aids. Trees were felled haphazardly, depending on their lean, crown structure, and wind direction. On a per-tree basis, the improved value recovery associated with feller-buncher felling does not seem significant. However, applied to a whole compartment or over the entire annual harvest of a forest company, the economics become more important. For example, a forest enterprise may be harvesting 1000 ha of P. elliottii, with a stocking level of 300 stems per ha and a mean DBH of 50 cm. Based on our results, if the trees were felled with conventional chainsaw practices, value recovery would be $23.95 million (not considering harvesting, transport, and management costs). For trees harvested with a fellerbuncher, however, value recovery would be $25.41 million, an increase of $1.46 million. Therefore, if breakage is reduced during the felling operation, the total production of higher-value timber is increased and timber resources are CWFI 3506 FDC 302 4

5 better utilized. CONCLUSION AND MANAGEMENT IMPLICATIONS Because tree volume recovery rates differed little between felling methods, we could not attribute the higher value recovery from feller-buncher felling to improved volume yield. Therefore, any improvements must have been due to lower effective stump heights; better log-class availability because of less breakage (i.e., more and highervalue sawlogs optimized from the stem); and a difference in breakage characteristics (i.e. breaks occurring in the pulpclass diameters, where timber is of lower value). In South Africa, forest companies invest heavily in pruning to produce high-value, knot-free timber. This clear, large-diameter timber at the butt end must be fully utilized, which means minimizing stump heights, regardless of felling method. Although feller-buncher harvesting usually results in lower effective stump heights, these can be further reduced if undergrowth is cleared before felling. Likewise, effective stump heights as well as tree damage can be reduced during chainsaw felling if undergrowth is removed and operators minimize breakage. Our study conditions involved only a moderate slope with smooth-ground roughness. The difference in value recovery between the two felling methods should be greater when slope and roughness increase. Feller-bunchers have greater control of the trees and better directional-felling capabilities compared with chainsaw felling. However, the feller-buncher is limited more by extreme slope and groundroughness conditions than is the chainsaw operator, so that chainsaw felling sometimes is the only option. When selecting a harvesting system, managers must consider value recovery as well as typical factors of productivity and harvesting cost. In addition, the availability of proper equipment and worker training needs must be addressed. Directional felling aids are simple tools that are inadequately utilized within the South African forest industry. Management principles apparently target daily production more than timber volume and value utilization. Operators, therefore, are more concerned with the number of trees they must fell within a shift rather than with the benefits derived from felling aids. Directional, rather than conventional, chainsaw felling should enhance value recovery, particularly in rough terrain. Productivity probably also increases when larger pieces (i.e., fewer small sections) can be extracted. Likewise, a better lay of timber contributes to shorter extraction distances and easier load-pickup with grapple skidders. Management decisions and worker training efforts must introduce a culture of directional felling in stands where it will be beneficial. In older stands with large trees, the main objective should be breakage reduction; in stands with smaller trees, the focus should be on directional felling to improve extraction. To help fulfill wider-scale workforce training needs in South Africa, the government introduced the Skills- Development Act in 1998, which outlines a new national training strategy. Efforts are underway in forestry to develop training-unit standards and accredited training programs for its workforce. FESA (Forest Engineering South Africa) is an industry-sponsored organization that is setting training-unit standards for a National Qualifications Framework (Conradie, 1999). For example, the unit standards being set for mechanized harvesting will help identify and improve training requirements for equipment operators. Education in safety and productivity will help improve performance and it should include an awareness of how an operators actions affect tree volume and value recovery. This will go a long way toward improved felling and resultant wood value recovery. REFERENCES Anon Economic significance of high stumps. Silvicultural Leaflet No. 8. Department of Mines and Resources, Canada. 1 p. Conradie, I Forest engineering skills training in the new millennium A South African perspective. In: Conference Proceedings Timber Harvesting and Transportation Technologies for Forestry in the New Millennium. Pietermaritzburg, South Africa, L. Kellogg and P. Licht (eds), Oregon State University, Department of Forest Engineering, Corvallis, USA. 206 p. Conway, S Timber Cutting Practices, A Manual on Felling and Bucking. Miller Freeman Publications, Inc., USA. Erasmus, D National terrain classification system for forestry, National Terrain Classification Co-operative. Institute for Forestry Research, Pietermaritzburg, ICFR Bulletin Series 11/94:1-11. Fraser, D., Palmer, D., McConchie, M., and Evason, T Breakage in manually-felled clearfell Radiata pine. LIRO Limited, Rotorua, New Zealand, Project Report 63. Guimier, D.Y Directional felling of large old-growth cedar trees. FERIC, Canada, Technical Report No. TR- 43:1-4. Kewley, S Timber value recovery: A case study of motor manual and mechanised feller buncher felling. Forest Engineering Honours Thesis, University of Stellenbosch, South Africa. 104 p. CWFI 3506 FDC 302 5

6 Murphy, G Directional felling of old crop Radiata pine on steep country. New Zealand Journal of Forestry 27(1): Murphy, G Felling breakage and stump heights of a P. radiata stand in Tairua State Forest. New Zealand Forest Service, Forest Research Institute Bulletin No. 57:1-9. Murphy, G. and Gaskin, J.E Directional felling second crop P. radiata on steep country. LIRA, New Zealand, Report 7(1):1-4. Murphy, G., Twaddle, A.A., and Cossens, P How to improve value recovery from plantation forests: Research and practical experience in New Zealand. Proceedings: COFE 1991 Annual Meeting: Canada. Nixon, G.R.W Breakage and other losses in logging on the British Columbia coast. Forest Products Laboratories of Canada, Department of Northern Affairs and National Resources, Canada, p Warkotsch, P.W Harvesting of pine and eucalypt in South Africa. South African Forestry Journal 147: Warkotsch, P.W The Relevance of Harvesting in Forestry Handbook, The Southern African Institute of Forestry, p Warkotsch, P.W The impact of harvesting operations on timber quality: Causes and remedies. South African Forestry Journal 169: Wirz, R Who Can Afford This? (Report by a German forestry student working for Mondi Forests, Sabie.) Zaremba, W Logging Reference Manual, Vol. 1. Bulletin 52, Department of Forestry, South Africa. p CWFI 3506 FDC 302 6