Études de cas

Click to view report FAO. 2008. Étude de cas sur l'exploitation forestière - 24.
Gestion durable des produits non ligneux dans la concession forestire de Pallisco . FR
  Au Cameroun, les concessions forestières attribuées couvrent 42,95% des 14 millions d’ha qui font l’objet du plan d’affectation des terres forestières. L’objectif principal de ces concessions est la production de bois d’oeuvre. Celles-ci sont aussi utilisées par les populations locales pour satisfaire leurs besoins de subsistance et pour améliorer leurs revenus à travers l’exploitation des produits forestiers non ligneux (PFNL) qui s’y trouvent. Parmi les essences exploitées par le concessionnaire, certaines sont des PFNL qui sont aussi prisées par les communautés riveraines.

Click to view report FAO. 2007. Étude de cas sur l'exploitation forestière - 23.
The impact of timber harvesting on the availability of non-wood forest products in the congo basin . EN FR

This study seeks to examine the impact of timber harvesting in two villages, one in Cameroon and one in the Central African Republic. It documents many plant-based and animal-based NWFPs of great signifi cance to the livelihoods of the local populations in terms of food security, income generation and health.

With regard to the impact of logging on NWFP availability, the study fi nds that the greatest impacts have been on tree species with NWFP values that are extracted by the timber companies. Timber exploitation also leads to the destruction of secondary trees and understorey species that furnish NWFPs. Damage is associated with tree falls and the passage of heavy machines that also destroy NWFPs. Apart from a few NWFPs that benefi t from logging-induced microclimate changes at the forest fl oor, most plant-based NWFPs decrease in availability following logging. With regard to the availability of animal-based NWFPs, the overall trend is also one of decline after logging.

The forest of the Congo Basin is a major economic asset for national governments, local communities and economic operators. With the drive towards sustainable forest management, it would be ethical to take into consideration all stakeholders in designing policy, management and control tools that minimize the negative impacts of logging and encourage multiple benefits from a greater array of forest products. The study recommends that policies governing forest exploitation should: • ensure that timber companies establish a platform where local communities’ voices can be heard;
• arrange for the local population, the administration and the logging company to work together to draw up social responsibility contracts and clarify the role of NWFPs in management plans;
• create agroforestry zones that would enable local people to operate in their own domain while the logging company operates on its own area, thereby reducing conflict;
• ensure systematic multi-resource inventories especially of timber species with NWFP values;
• help develop alternative activities of interest to the local population;
• involve local non-governmental organizations in the overall strategy of education and information dissemination on the rights of all stakeholders;
• ensure proper monitoring of logging activities;
• improve forest governance and reduce illegal logging;
• minimize disparities in the forest policies of the Congo Basin countries.

Click to view report FAO. 2005. Étude de cas sur l'exploitation forestière - 22.
Pitsawn timber production in natural forests of Uganda. EN

The case study was conducted to highlight the impacts of pitsawing in Uganda and the approach of policy-makers to this industry. This report provides an assessment of current forest management practices, forest policies and laws with regard to pitsawing.

The report also analyses the prevailing policies that have indirectly encouraged the emergence of the industry. The management policy has favoured the promotion of pitsawing in Natural Forest Reserves, with licences to operate up to four saws per sawyer under a strict zoning policy. There are many mobile sawmills, but all are licensed and working in the softwood plantations. However, there is a ban on the use of chainsaw and any motorized tool in timber production in natural forests.

The report provides an analysis of the local and export timber markets. The supply of timber from natural forests is declining and forest continues to be lost at an alarming rate. Uganda’s forests have a total economic value of about US$1070 million. Of this, only 7 percent (US$75 million) is derived from sawn timber with pitsawing providing about 90 percent of the sawn timber on the local market. The size of the local timber market is estimated at 240 000 m3 from current harvesting of roundwood, which is twice the sustainable annual allowable cut. The domestic market has been the major market for Ugandan timber for the last 50 years. Despite a ban on timber exports, Kenya is main market for Ugandan hardwoods. The forest resource is too small to sustain a large export trade in timber and other primary wood products. However, there are possibilities for a lucrative trade in secondary wood products.

The study evaluates the effect of pitsawing operations on the community adjacent to the Kalinzu Central Forest Reserve in western Uganda. It examines the livelihood systems of the pitsawyers and the target community, and also analyses changes, opportunities and constraints to livelihood systems if pitsawing activities were to be stopped. Farming and pitsawing are the main sources of livelihood for the local community. The community allocates most of its income to basic daily needs, investing little in other enterprises. Pitsawing sustains livelihoods for several categories of people (e.g. supervisors, sawyers, carriers, sellers and buyers).

This report contains recommendations for follow-up on pitsawing. It concludes that support is required to identify and develop alternative livelihood options to offset any short-term drop in income felt by poorer households.

Click to view report FAO. 2005. Étude de cas sur l'exploitation forestière - 21.
Chainsawing in the natural forests of Ghana. EN

Chainsawing in Ghana is a subset of illegal forest activities. Therefore, the report examines the past actions or inaction that have encouraged illegal timber harvesting activities as well as the capacity of the Forestry Commission (FC) to deal with them. Law enforcement and governance are important with regard to the control of illegal forest activities. Hence, the various elements of governance in practice in Ghana have been reviewed in order to determine how chainsawing can be minimized and how transparency, accountability, civil society participation, law enforcement, and the tracking of chainsawn lumber improved.

Among its findings, the study highlights the fact that about 60–80 percent of the chainsaws used in chainsawing belong to lumber dealers located far from the source of the timber. Hence, focusing on the operators alone with regard to alternative livelihood schemes would not be effective as the dealers would find other means to reconnect the chain. Measures to make the trade in chainsawn lumber less profitable, so affecting all categories of ownership, e.g. through the payment of the real prices for logs to the farmers and the payment of the appropriate forest fees, may be more effective.

The study concludes that the three main factors driving chainsaw lumbering are:
• an inadequate supply of legal lumber to the local market;
• weak law enforcement and governance structures;
• rural economic decline.

Of these, first two have been identified as the driving forces that will determine the future of chainsawing in Ghana. The two forces have been used to derive possible scenarios for the future of the trade in Ghana. Recommendations have consequently been made with regard to the realization of a selected scenario (Green Ghana) that would facilitate the regularization of chainsawn lumber production as well as possible alternative livelihood schemes. Owing to the extent of the study area and the mode of choice of respondents (i.e. the use of the criteria of cooperativeness and of intermediaries at times), the recommendations should be regarded as “flags” on issues that require further attention.

Click to view report FAO. 2005. Étude de cas sur l'exploitation forestière - 20.
Forest operation improvements in farm forestry in Slovenia. EN

Click to view report FAO. 2002. Étude de cas sur l'exploitation forestière - 19.
Environmentally sound forest harvesting in Brazil. EN

This study is a follow-up to a previous study in this series (Winkler 1997). Both studies were undertaken in a managed natural forest near Itacoatiara in the Amazon region of Brazil. The two studies were conducted in collaboration with Precious Woods Amazon (PWA). The purpose of this reexamination was to assess the condition of the forest four years after logging had been completed. For this purpose, assessments were undertaken on regeneration within felling gaps and on skid trails, water infiltration rates on skid trails, the current status of potential crop trees and the condition of residual trees of commercial species.

Two plots, one treated with "conventional" logging techniques and the other with "environmentally sound" harvesting system were examined. Regeneration of seedlings, saplings and poles of both commercial and non-commercial tree species was generally satisfactory and appeared adequate to permit full recovery of the forest ecosystem over time. In addition, there was no significant difference in the numbers or sizes of tree regeneration, or in the numbers of tree species regenerating, between the two treatment areas. Regeneration on skid trail ruts was significantly less when compared to the less deeply disturbed side strips or centre strips on skid trails. There was no significant difference in regeneration in skid trails or in water infiltration rates on skid trails between the two treatment areas.

Click to view report FAO. 2002. Étude de cas sur l'exploitation forestière - 18.
Commercial timber harvesting in the natural forests of Mozambique. EN

The present study analyses five enterprises in northern, central, and southern Mozambique. Efficiency is evaluated by means of operational, organizational, energy, and financial indicators. Operational data were collected through time studies with continuous timing. Costs per machine-hour were calculated with the "Production and Cost Evaluation Programme - PACE" (FAO 1992). Intermediate results on output were then related to those on input, yielding indicators for operational efficiency, organizational efficiency as well as energy and financial efficiency.

As a consequence of operational and organizational impediments, production was extensive in terms of extraction volume and intensive in terms of workforce, energy, and capital. Results suggest that the efficiency of commercial timber harvesting as practised under the conditions observed during this study, generates little or no benefit and hardly justifies extracting resources which should be considered precious and polyvalent assets for rural communities, the national economy, and the global biosphere. Recommendations from the study focus on raising extraction intensity through harvest preparoptimised use of all available commercial species, and on reducing production costs by restricting transport distances and by allocating processing units as close as possible to logging areas.

Click to view report FAO. 2002. Étude de cas sur l'exploitation forestière - 17.
Financial and economic assessment of timber harvesting operations in Sarawak, Malaysia. EN

Timber harvesting with tractors is the standard extraction method in the Mixed Hill Dipterocarp Forests of Sarawak, Malaysia. Conventional Logging (CL) systems cause substantial disturbance and damage to forest stands and the environment. This is why over the last few years, Codes of Practice on Reduced Impact Logging (RIL) have been developed and implemented in many trial areas of tropical natural forests. A Cost-Benefit-Analysis (CBA) reported in this study compares the project worth of two timber harvesting systems: (1) Conventional Logging (CL) and (2) Reduced Impact Logging (RIL). Two time frames are included in the analysis: (1) One-year calculation period; the financial costs and revenues of CL and RIL are calculated for the year of harvest in a primary forest; (2) 40-year calculation period; the financial and economic project value is analysed until year 40 after logging, which includes timber production from a second harvesting operation. Data on cost, productivity, and damage to the residual stand as well as data on soil compaction were obtained from RIL and CL trial blocks in the FOMISS-Sampling Pilot Area (FSPA). In addition, timber wastes due to poor utilization and lost logs are estimated based on data collected in the area. Figures on forest growth are predicted with the Dipterocarp Forest Growth Simulation Model (DIPSIM).

From the concessionaire's point of view the CL system is more profitable. But, it should be emphasized that the application of RIL techniques in the FSPA is still in its infant stage. In other words, there are ample opportunities for further improvements in cost cutting, harvesting intensity and sales revenues, as well as skills and efficiency of forest workers and machineries.

Click to view report FAO. 2001. Étude de cas sur l'exploitation forestière - 16.
Forest harvesting practice in Concessions in Suriname. EN

The study was carried out in a tropical natural forest of the Guyana Shield in the Forest Belt of Suriname close to Kabo, district of Para. One of the numerous small concession holders serving the local timber market was identified and proved willing to host this study, which required the application of "planned" harvesting on the cooperator's timber concession number 387. The objective was to provide a comprehensive analysis of planned harvesting as an alternative to the conventional way of logging as usually carried out in Suriname. The study documents each phase of the conventional logging system, which is used almost exclusively in Suriname's small timber concessions and was applied on one sample plot at the study site. The productivity and environmental impacts associated with this system are compared with those of planned harvesting as applied on the other sample plot in concession 387. Data on the two harvesting operations were collected under almost identical conditions. Work and time studies on harvesting activities in both systems and post-harvest assessments of environmental impacts, were carried out in the adjacent sample plots at the study site.

Perhaps the most important finding of this study is that planned timber harvesting can reduce costs significantly in comparison to conventional logging, in contrast to the strongly held belief that "reduced impact" logging must necessarily cost more than "high impact" logging. The results of this study suggest a labour-cost advantage of more than 20 percent for planned harvesting as compared to conventional logging. This result is of course specific to the conditions under which this study was conducted and cannot easily be generalized.

Click to view report FAO. 1998. Étude de cas sur l'exploitation forestière - 15.
Forest harvesting operations in Papua New Guinea; The PNG Logging Code of Practice. EN

The study was carried out in tropical natural forest of Sandaun Province and on New Britain Island, both Papua New Guinea (PNG). Two timber permit holders, namely Vanimo Forest Products Pty Ltd. (VFP) and Stettin Bay Lumber Company Ltd. (SBLC), agreed to host this study on forest harvesting operations in Papua New Guinea. The study documents each phase of the forest harvesting system currently applied by the above-mentioned companies and compares planning and implementation of harvesting operations in the field against relevant regulations as published in the Papua New Guinea Logging Code of Practice. Data on felling operations were collected through work and time studies at both study sites, whereas data on extraction was collected only at the VFP site in Sandaun Province. As one part of a post-harvest assessment of environmental impacts, a survey of skidtrails was carried out at the study site in the Sandaun Province.

The results of this case study show that, although major steps are already being taken to foster environmentally sound forest harvesting through the introduction of the "Planning, Monitoring and Control Procedures for Natural Forest Logging Operations" under Papua New Guinea's Timber Permit system and by implementing the PNG Logging Code of Practice, much remains to be done.

Click to view report FAO. 1998. Étude de cas sur l'exploitation forestière - 12.
Environmentally sound forest infrastructure development and harvesting in Bhutan. EN

The study was carried out in natural forests of the Himalayan range in Bhutan in the spring of 1998. The Third Forestry Development Project (TFDP) in Eastern Bhutan was selected to demonstrate that ¿Environmentally Friendly Forest Engineering¿ considerably reduces the effect of damaging elements of forest road construction. The study documents each phase of both environmentally sound road construction by excavators and traditional road construction by bulldozers and compares environmental impacts of both construction techniques. Another objective was to provide information on ¿long-distance cable crane logging¿ which will probably continue to be the most common harvesting system applied throughout Bhutan in the near future. The traditional clear-felling practices as well as a modified technique both with subsequent cable logging were studied. Data on road construction were collected for both construction techniques under similar formation conditions in forest management units (FMU) of the TFDP. Work and time studies on construction operations by excavators were carried out in the Kharungla unit and on construction operations by bulldozers in the Korila unit. The work and time studies on long-distance cable logging were carried out in the Korila unit for the traditional way of harvesting and in the Chamgang-Helela unit, which is not part of TFDP.

The results of this case study show that environmentally sound road construction, as applied in the Kharungla road project, is superior to road construction in the traditional way by bulldozers as applied at the Korila construction site from the environmental point of view. The short-term economic benefits from use of bulldozers in forest road construction in mountainous terrain are likely in the longer run to create environmental damage on a considerable scale as side slopes increase.

Click to view report FAO. 1998. Étude de cas sur l'exploitation forestière - 11.
Reduced impact timber harvesting in the tropical natural forest in Indonesia. EN

The study was carried out in the tropical natural forest, concession area of PT. Sumalindo Lestari Jaya IV in Berau Regency, East Kalimantan, Indonesia. This study analyses productivity, costs and environmental impacts of conventional and reduced impact timber harvesting of the Indonesian Selective Cutting and Planting (Tebang Pilih Tanam Indonesia/TPTI) system. Both methods of harvesting used the same equipment and operators and were conducted in almost the same area. Felling was done with heavy chainsaw and skidding with crawler tractor (bulldozer). Time studies were elaborated for felling, skidding, bucking, loading, hauling and unloading activities to assess timber harvesting performances, productivity and costs under comparable conditions of conventional and reduced impact timber harvesting. Environmental impact assessments were carried out only for the felling and skidding operations.

These research results indicate that conventional timber harvesting with the TPTI System in the tropical natural forests of Indonesia caused heavier damage to soil and residual stands when compared with a reduced impact timber harvesting system. The application costs of reduced impact timber harvesting are not greater than conventional timber harvesting in either short or long periods because the value of wood damages caused by conventional timber harvesting is twice as great as that caused by reduced impact timber harvesting. Also, reduced timber harvesting will enhance future forest productivity and reduce the costs associated with potentially adverse side-effects of timber harvesting.

Click to view report FAO. 1998. Étude de cas sur l'exploitation forestière - 10.
Environmentally sound forest road construction in mountainous terrain. EN

The study was carried out in semi-natural forests of the Alps in the province of Salzburg, Austria and documents each phase of environmentally sound road construction by excavators and advanced blasting technique as applied in the road projects under review and compares its environmental impacts with those of the traditional road construction by bulldozers. Data on road construction was collected under different terrain and formation conditions. Work and time studies on construction operations by excavators were carried out at all construction sites and blasting operations where observed in one road project where substantial rock blasting was specified.

The marked superiority of road construction by excavators, including the use of advanced blasting technique, over the traditional road construction techniques by bulldozers is underscored by the results of the qualitative assessment of environmental impacts in the environmentally sound road construction practice under review. This practice encourages a reduced area dedicated to permanent forest infrastructure, reduced disturbance of the landscape, satisfactory water drainage, effective erosion control and negligible damage to forest stands alongside roads.

Click to view report FAO. 1997. Étude de cas sur l'exploitation forestière - 9.
Labour-intensive harvesting of tree plantations in the southern Philippines. EN

This publication presents the experiences of simple, labour-intensive harvesting of timber from tree plantations in the southern Philippines. The case study illustrates the potential for supplying large volumes of industrial wood to modern processing mills using simple tools and techniques in a cost efficient and environmentally sound manner. In the process, jobs are provided to thousands of people, helping to satisfy social objectives in areas of few alternative livelihood opportunities. It is hoped that by increasing awareness of the experiences in the southern Philippines, foresters and development officials in other areas will recognize the potential of simple, labour-intensive systems as viable options for timber harvesting and job creation.

Click to view report FAO. 1997. Étude de cas sur l'exploitation forestière - 8.
Environmentally sound forest harvesting: testing the applicability of the FAO Model Code in the Amazon Basin in Brazil. EN ES

The study was carried out in the tropical natural forest of the Amazon near Manaus, Amazonas, Brazil. Precious Woods Company Ltd. initiated the project to demonstrate the economic viability of sustainable forest management integrated with a wood-processing industry. This, as an alternative to the timber exploitation usually carried out in the Amazon region of Brazil. The study documents each phase of the environmentally sound forest harvesting system as applied by Precious Woods and compares its efficiency and environmental impacts with those of the traditional logging systems generally used in the Amazon region. Comparable data on harvesting operations were collected under almost identical conditions. Work and time studies on harvesting activities in both systems and post-harvest assessments of environmental impacts were carried out in adjacent cutting units of the project area.

The results of the study show that environmentally sound timber harvesting is not necessarily more expensive than timber harvesting done in the traditional way. The advantage easily goes to the environmentally sound forest harvesting system when it comes to meeting other economic, social, and environmental objectives.

Click to view report FAO. 1997. Étude de cas sur l'exploitation forestière - 7.
Forest harvesting in natural forests of the Republic of Congo. EN FR

The report presents findings of a case study on forest harvesting in natural forests of the Republic of the Congo and was carried out in collaboration with a private industrial enterprise operating a concession there. The concession consists of approximately 150 000 ha of closed canopy, broad-leaved forest located in the Chaillu Massif in southern Congo, at the border to Gabon. The aim was to establish a reliable database on a ground harvesting system in the tropics using power saws, crawler tractors and wheeled skidders. The case study consisted of a study inventory, a harvesting performance study and a harvesting impact assessment. The size of the study area was 150 ha, subdivided into three harvesting compartments of 50 ha each. The low concentration of harvestable trees played an important role in harvesting efficiency and site impact.

Click to view report FAO. 1995. Étude de cas sur l'exploitation forestière - 6.
Impacto ambiental de las prácticas de cosecha forestal y construccion de caminos en bosques nativos siempreverdes de la X región de Chile. ES

Este trabajo comprende dos aspectos principales. Primero recoge lo esencial de las actuales practicas de cosecha forestal y construcción de caminos en bosques siempreverdes de la X Región de Chile, describiendo los métodos, la organización del trabajo, la productividad de los sistemas y costos referenciales. Una segunda parte presenta una evaluación cualitativa del impacto ambiental de estas faenas de cosecha sobre los diferentes componentes del medio ambiente natural e incluye una proposición de medidas y tecnologías mejoradas para mitigar los impactos negativos de las operaciones de cosecha y construcción de caminos forestales sobre el medio ambiente. Esto, sobre la base de un análisis descriptivo, una revisión bibliográfica, información de empresas, la observación de operaciones y la experiencia del autor en estudios de casos. Además el análisis general hace referencia a las regulaciones a las que están sometidos en Chile este tipo de proyectos de cosecha forestal y comprende una descripción general del ambiente afectado en el área de estudio.

Click to view report FAO. 1995. Étude de cas sur l'exploitation forestière - 5.
Elephants in logging operations in Sri Lanka. EN

The elephant was used for hauling logs in forest operations for hundreds of years before the mechanization of forest harvesting technology. However, with technological development, man gradually replaced the elephant with the motorized tractor, with greed driving the need to produce more and more in an industrialized world. Higher productivity was gained, but at the cost of heavy and permanent damage to the forest ecosystem, especially in rain forests, with consequent negative environmental impacts. There is now much concern globally to stop such destruction and even to stop trade in tropical hardwoods. It was in the context of environmental responsibility that a review of the advantages and disadvantages of using elephants in logging operations was carried out in Sri Lanka.

Click to view report FAO. 1995. Étude de cas sur l'exploitation forestière - 4.
Use of construction crane for wood extraction on mountainous terrain. EN

The case study was carried out in the Republic of Austria at two harvesting areas with 105-year-old and 75-year-old stands of spruce, amply supplied with natural regeneration in the understorey. The purpose of this case study was to assess the productivity and costs of a wood harvesting system appropriate to silvicultural systems that provide natural regeneration. Two harvesting methods were observed: the modified full-length method and the whole-tree method. Modified full-length method means that delimbing and topping of the trees take place at the felling site and that bucking (or cross-cutting) is carried out after transfer to the forest road. With the whole-tree method, felling and trimming are done in the stand. Time studies were carried out only for the logging phase to assess logging performances which can be expected under particular conditions.

Click to view report FAO. 1995. Étude de cas sur l'exploitation forestière - 3.
Uso de bueyes en operaciones de aprovechamiento forestal en areas rurales de Costa Rica. ES

El objetivo principal de este informe es presentar un panorama general sobre la utilización de bueyes en las áreas rurales de Costa Rica. La información contenida permite hacerse una idea sobre las limitaciones existentes y la utilización actual y potencial de bueyes en actividades forestales en áreas rurales de Costa Rica y Centro América. Se incluye información sobre las condiciones que deben existir para obtener los mejores resultados del uso de los animales, sobre los costos y rendimientos de los animales en las labores de extracción y se comparan estos costos con los de la utilización de tractores de oruga. En base a la información analizada se presentan las conclusiones sobre las ventajas sociales y económicas que puede representar el uso de bueyes y las limitaciones que impone su empleo para el desempeño apropiado de las operaciones en algunos bosques tropicales, debido principalmente al gran tamaño de los árboles y a lo escarpado del terreno.

Aparte de la ventaja del bajo costo de producción que implica el uso de los bueyes, se considera como uno de sus principales beneficios el empleo intensivo de mano de obra que implica. Mientras que en el uso del tractor de oruga sólo el 14% de los costos totales corresponde a mano de obra, en el uso de los bueyes el 82.64% del total de costos, corresponde a costos de mano de obra.

Click to view report FAO. 1993. Étude de cas sur l'exploitation forestière - 2.
Cosecha de hongos en la VII región de Chile. AE

Pour analyser la récolte de champignons dans la VIIe région du Chili, est présentée une étude analytique qui concerne une commune (Empedrado) de cette région. L'auteur examine les différentes étapes de cette activité et les acteurs qui y participent, activité qui revêt chaque année plus d¿importance dans le cadre des ressources forestières non ligneuses. Il identifie des caractéristiques qui sont normalement communes à la majorité des pays latino-américains, à savoir le régime de propriété de la terre et la situation économique, sociale et culturelle marginale de la population dans le secteur rural de ces zones forestières. Chaque aspect est analysé, et cette étude décrit pour conclure des activités déterminées qui exigent une solution.

Click to view report FAO. 1992. Étude de cas sur l'exploitation forestière - 1.
Reduction of wood waste by small-scale log production and conversion in tropical high forests.

Une scierie portable, appelée Wokabout Somil en pidgin mélanésien, a été mise à l'essai en Papouasie-Nouvelle-Guinée en mai et juin 1990. L'étude de cas visait à mesurer et analyser la productivité, le taux de récupération et la qualité des sciages de la scierie, afin de réduire davantage les déchets et d'améliorer l'utilisation du bois rond dans les opérations d'exploitation commerciale en Papouasie-Nouvelle-Guinée.

Les données techniques concernant la scierie ont été recueillies pendant un essai de terrain mené au chantier d'exploitation de Kui, à environ 120 km au sud de Lae. Dix échantillons de billes ont été sciés et le temps employé et les données sur la récupération ont été enregistrés. On a observé que la consommation de bois rond par heure de la scierie variait entre 0,5 et 2,5m3/h en période de travail. Si l'on tient compte du transport et du temps de déplacement de chaque bille, la taille de la bille représente un facteur clé dans la détermination de la productivité. Sur la base du temps effectif, on peut affirmer que la longueur de la bille exerce un effet important sur la productivité de la scierie. Le taux de récupération variait entre 45 pour cent et 56 pour cent. Le taux de récupération d'une Wokabout Somil dépend dans une très large mesure du modèle de sciage adopté. La production journalière de sciages variait entre 1,0 m3/jour et 2,0 m3/jour en fonction de la compétence des scieurs.

lastUpdate  mercredi 26 novembre 2008