5 SECTION : Technical aspects

13. Appropriate Forest Harvesting and Transport Technologies for Village-based Production of Bamboo Charcoal in Mountainous Areas of Northern Lao PDR

BERNHARD MOHNS
LAO-GERMAN PROGRAMME ON RURAL DEVELOPMENT IN
MOUNTAIN AREAS OF NORTHERN LAO PDR
BOKEO
LAO PDR

Introduction

With a forest cover of over 60%, Northern Lao People’s Democratic Republic (Lao PDR) has considerable development potential for forest-based industries. This resource is currently being used primarily for swidden agriculture or exploited as round wood to neighboring countries. This is leading to a situation where forest areas consist of remnant forest largely depleted of valuable timber, or heavily degraded secondary vegetation that has undergone several cycles of shifting cultivation. These degraded sites are often dominated by bamboo stands. Thus, any future scenario for forest industry development, and forest rehabilitation for commercial purposes, will have to take into account the sustainable use of the present stock of small-sized woody biomass and bamboo.

In contrast to saw logs, which have a high value to volume (weight) ratio, the financial value of wood (and bamboo) for fuel, charcoal, pulp, particle board, bamboo plywood or other applications is entirely dependent on the cost of extraction from the forest stands and subsequent transport by roads or rivers to processing sites. Northern Lao PDR has very limited road infrastructure. This situation is expected to improve considerably with the ongoing construction of a road linking Thailand (Chiang Mai) with China (Kunming). In conjunction with this axis, a network of rural feeder roads is presently underway in the study area, which will eventually create an economic corridor interlinking the three countries.

The removal of bedrock from the Mekong River over the last 10 years allows for year-round navigation along the river from China to Chiang Saen in northern Thailand. Improved harbors and loading facilities are presently under construction at several points in northern Lao PDR. With improved accessibility by road and water, the forest resources of northern Lao PDR will gain interregional importance in the near future.

Industrial-scale forest harvesting in Lao PDR has been carried out under a system of concession logging, mostly by companies from neighboring countries. Harvesting technologies for such operations have been imported and range from converted agricultural tractors, bulldozers and specialized skidders to cable logging systems. Local community involvement has largely been omitted from this process, and in many cases their traditional access and use of forests has been infringed upon considerably by such concessions.

The present policies on land use in Lao PDR over the next decade focus on the elimination of shifting cultivation and creation of permanent settlements. Within this framework, concepts of community forestry have so far focused only on the utilization of forest products such as non-timber forest products (NTFPs), firewood and construction timber for domestic demand. Strategies for involving communities in more broad-based forest harvesting and processing activities (Lawlor et al. 2004) have so far not been developed for the secondary forests of northern Lao PDR. Experiences from the Finland/ World Bank funded FORMACOP project (1996–2002) in southern Lao PDR have only limited applicability in the secondary forests of the north, since that project focused on community participation in harvesting higher value round wood only. A recently established study site in southern Lao PDR under the FAO-supported regional project, “Enhancing Sustainable Forest Harvesting in Asia,” involved local communities in the harvest of small-sized residual wood from forest concessions. The lack of appropriate technologies for the extraction of such material has already become evident as an issue in this project.

The Lao-German Programme on Rural Development in Mountainous Areas of Northern Lao PDR (RDMA) is presently working on concepts for community-based forest management as a component of both village and regional economic development, covering clusters of villages or complete districts. In this context, the commercial-scale production of bamboo charcoal in several villages along the Namtha river in Pa Oudom District, Bokeo Province, is a first step toward developing sustainable forest utilization as an income generating activity, over and above supplying for local demand. This study focuses on the importance of appropriate forest harvesting technologies for use by local communities.

A recent review by USAID on community forestry projects, oriented towards wood processing and marketing, in six countries, indicates that none of the projects could show conclusive evidence of community control over all stages of the value chain (Lawlor et al. 2004). A major common obstacle is the lack of control over extraction and transport processes. It follows that rural communities can only benefit considerably from woody biomass-based value chains if technologies are available to them which allow their control over the initial stages of tree felling, and transport to the sites of selling, processing or loading for road or river transport (Lux 2005). The lack of appropriate forest harvesting technologies has two additional crucial aspects:

• Commercial-scale harvesting of (low-value) wood biomass components without means for covering greater extraction distances will eventually lead to over-exploitation of resources along access roads or points of processing. It is therefore critical for decision makers to recognize that commercial viability of harvesting needs to be incorporated into sustainable management plans for specific forest areas.
• Due to the lack of appropriate harvesting technologies, reforestation with commercial-scale forest plantations (teak) has so far only been undertaken in areas surrounding roads and navigable rivers, thereby occupying sites that could otherwise be brought under considerably higher value land use due to their accessibility or soil conditions.

Small-scale forest harvesting in the community forestry context

The terms “small-scale forestry” or “small-scale forest harvesting” have been used mainly in European and North American forestry circles. In general, they refer to timber harvesting operations carried out by owners of smaller woodlots in contrast to larger scale government or industrial operations. Harvesting technologies in this context are within the financial reach of individual forest owners or producer groups, and are very often linked to farm machinery such as logging winches mounted on agricultural tractors, these being the standard equipment of most farm forestry operations in Europe.

In recent years, the Forestry Institute of Garpenberg, Sweden, and the UK Forestry Commission have conducted extensive research on the economic and ergonomic performance of a wide range of small- scale forest harvesting equipment (Mitchell 1996). For the special conditions of small-scale harvesting in mountainous areas, the well-documented AUSTROFOMA exhibitions by Austrian manufacturers of forest harvesting equipment is an excellent source of information. Most of the information from these sources is highly applicable to the rural development context of Southeast Asia.

In Southeast Asia, the topic of forest harvesting has in recent years been dominated by the term ‘reduced impact logging,’ which refers to improved methods of pre-harvest tree inventories, directional felling and extraction methods aimed at reducing damage to the “mainly natural” residual forest stands. The harvesting systems promoted under this concept have focused entirely on large- scale forest operations. Involvement of local communities and small-scale forest enterprises has so far been largely left out under the reduced impact logging approaches. This is due largely to the fact that such actors play only a minor role in commercial scale wood-extraction operations. As such, information on the application of appropriate technologies for forest harvesting at levels below state- owned or concession forest enterprises remains very limited in the region.

Project context

During a recent analysis of various value-chain options for non-agricultural income generation, and based on earlier forest resource assessments for Bokeo Province, it became apparent that industrial- scale processing of bamboo was a viable option for the RDMA target areas. Paktha village was selected in 2005 as an initial pilot site for bamboo charcoal manufacturing, storage and loading for transport by both river (Mekong) and road.

Under the RDMA’s private-public partnership concept, a tripartite agreement was drafted between:

• A private Lao enterprise engaged in bamboo-charcoal processing and export, whose role was to introduce special technology for high-quality charcoal production, provision of storage, packaging and loading facilities, and export marketing. The entrepreneur would obtain a bamboo concession, for which he would pay a royalty to the government for raw materials.
• The RDMA and its government counterpart organizations, whose roles were the preparation of forest management plans in the production areas, and introduce appropriate technologies to allow bamboo harvesting in an economically viable and ecologically sustainable way.
• Villages along the Namtha river that would engage in bamboo harvesting, transport and charcoal processing.

Under the agreement, the price for fresh bamboo was calculated at about US$17 per ton when delivered to the processing site at Paktha. The price for bamboo charcoal was estimated at US$110 per ton (including any future royalty payments to the government) at the point of road or river transport to northern Thailand. This price compares well with the present price range of US$90–130 per ton for this product in northern Thailand.

Assessment of forest biomass production and terrain conditions

Preliminary assessments were carried out on the extent of bamboo stands within the designated areas of upland agriculture and production forests within village boundaries and along the lower Namtha river. It was estimated that each charcoal kiln with an annual production of 30 tons of charcoal would require about 150 tons of green bamboo, which in turn could be harvested annually on a sustained basis from about 30 ha of bamboo stands (Dransfield and Eijada 1995). Sufficient bamboo resources could be found in most areas within a radius of 2–3 km around potential processing sites, assuming that subsequent transport of the charcoal was viaall weather access roads or rivers.

It was realized that the anticipated yearly production of 1,000 tons of charcoal could only be realized by either spreading kilns over a wide area, or by bringing green bamboo over greater distances to central processing sites by way of road or river transport. Cartographic assessments of slope class and direction were carried out in a corridor of 2 km on both sides of the Namtha River and over a distance of 180 km. In order to assess the potential bamboo resources in this corridor, aerial photo interpretation and visual assessments of transects were conducted at regular 5-km intervals during a cruise along the river. Both methods revealed that a total of about 55,000 ha would fall into the slope classes and directions that would allow for downhill skidding of bamboo to the river over maximum distances of 2,000 meters. It was estimated that approximately 20% or 11,000 ha of this area, is covered with exploitable bamboo stands.

Suitable bamboo stands were found along all-weather roads, covering a total distance of 35 km, with a maximum distance to processing sites of 22 km. Within these river and road corridors, an area of about 11,000 ha of bamboo stands are found within an accessible range of the proposed central processing site at Paktha. Following these studies, it was decided to carry out further research on the feasibility of harvesting and transporting bamboo under existing stand and terrain conditions.

Felling and bunching along skidding trails

Due to the difficulties in bringing individual bamboo culms to the ground, felling is done in teams of at least two persons. The culms are carried out with axes or straight-bladed machetes at a height of about 0.8 to 1.2 m above ground, due to the dense growth of culms at the base of the clumps. For the trials, culms were selected with a diameter at breast height of between 10 and 15 cm in order to minimize variation due to diameter and length differences and their effect on weight per piece. This diameter range is also most suitable for the construction of bamboo rafts, as used in the subsequent transport trials.

The distance to the skidding trails was kept to a maximum of 20 m to eliminate further variations. The performance of labor in the felling and bucking process was as follows: the time for cutting, dragging to the ground, cutting off branches and delivering the culms to a point of initial stacking along skidding trails took an average of 4.7 minutes per culm, calculated from a total of 180 culms harvested with a variation of between 3.3 minutes and 9.2 minutes. In cases where a group of culms was entangled and had to be brought down together, the time was calculated as an average of such a group of culms. The average culm harvested had a weight of 14.4 kg with 13.5 cm diameter and a length of 13.4 m.

Harvesting time per ton for a two-person team was 326 minutes, or in other words, one person was able to harvest about 0.5 tons in one day. Assuming an average wage of US$2 per day, the operation of felling and stacking at the skidding trail will cost approximately US$4 per ton. These costs for the felling and bunching operation are surprisingly high. Due to the low weight/volume ratio of bamboo, few options are available to improve the felling operation significantly (Efthymiou 2002). The costs might be slightly lower in situations where whole fields may be harvested in clear-felling operations.

Manual transport to loading sites

Manual transport of bamboo culms is presently the most common form of forwarding. This is mainly done for domestic consumption over distances of up to several kilometres. The optimal range for manual transport is between 50 and 150 m. For commercial-scale operations, the maximum range considered economically viable would be around 500 m for downhill transport. Due to the relatively high friction of long bamboo culms, manual transport is most suitable for this terrain condition. For transport over level or uphill terrain, the acceptable range diminishes considerably. Manual uphill transport on slopes steeper than 35–40 % is limited to distances of less than 50 m.

Horse logging

In spite of the extensive use of buffalo and cattle in agricultural operations and horseback transport by certain ethnic groups (Hmong, Yao), animal traction has so far not been applied to forest harvesting operations in the project area. Buffalo and cattle are mostly used in pairs, which makes them unsuitable for forestry operations along relatively narrow foot paths and skidding trails. The slow reaction capability makes these animals also very vulnerable to leg injuries during downhill skidding, where easy manoeuvrability is required. Suitable logging harnesses for these types of draught animals could also not be identified immediately (FAO 1986).

It was therefore decided to concentrate further investigations on horse logging operations. Harnesses, self-locking skidding chains and ropes were imported from Europe. Skidding troughs were manufactured locally from 2-mm tin sheets with two different opening widths (80 and 100 cm). Two horses the size of large ponies (shoulder height of 115 cm) were trained by a traditional Hmong horse-keeper in bamboo logging, using the above equipment. Performance of the horse-logging operations were tested on the two felling sites over level and downhill sloping (10–20%) terrain, and over distances of between 200 and 3,000 m with a total of 180 harvested bamboo culms.

Time for loading the skidding trough (shoe) with 10–15 culms for each trip and tying the bundle with a self-locking chain required an average of 4 to 5 minutes. The mean load per trip was 172 kg (with a range of 145 to 195 kg). During the observation of 21 roundtrips, the self-locking chains failed in only one case. The utilization of this kind of equipment was found to be indispensable, since it was not possible to tie bamboo culms with locally available material into bundles and drag them over larger distances without the slippage of individual culms leading to the loosening of the bundle. The economically viable maximum range for horse logging was found to be about 2500 m, keeping logging costs below US$ 10 per ton.

On steeper downhill sections, a second operator is required to apply tension to the load to prevent it from slipping into the rear legs of the horse or the feet of the front operator. This will increase costs for the operation on these terrain conditions by about 30%. Some preliminary trials to extract bamboo on steeper uphill terrain showed that the performance dropped dramatically. Further tests would be needed to establish accurate performance data, but it is suggested that the economically viable range for uphill skidding with horses on slopes above 20% would be reduced by about 50%. On slopes above 40%, horse logging will not be viable.

Development of a 2-wheel tractor-based mini-skidder

Due to difficulties in introducing horses to ethnic groups without previous experiences in keeping such animals, and the limitations of horse logging in terms of maximum skidding distance and poor performance on steeper slopes, it was decided to explore additional skidding technologies. The conversion of locally available 2-wheel tractors into a pedestrian operated skidding device was identified as the obvious alternative due to the following reasons:

• The basic technology of two-wheel tractors is widely spread in the RDMA target areas. One can easily remove the engine, gear box, and belt-driven device and combine it with other appliances such as water pumps, threshing machines, and small sized 4-wheel trucks.
• Over the last two decades, a variety of wheel- and rubber-tracked pedestrian operated mini-skidders have been developed in Scandinavian countries. They use motors in a power range similar to the 9 to 15 hp 2-wheel tractor. Two models, the Jonsereds Iron Horse (9 and 19 hp) and the Gustafsson Oxen (15 hp, described on www.gosta-gustafsson.se) find widespread application in the forests of northern Europe. An earlier model, the so-called Wheel Horse, was in its design nearly identical to the regionally available 2-wheel tractors, but it is no longer manufactured. (Forest Engineering Research Institute of Canada 1988)

A review of the literature on pedestrian-operated mini-skidders revealed the following data on their performance and operational costs (see also Table 1):

• The maximum loading capacity is in a range of 0.7 to 1.2 tons, whereby part of the load is dragged behind the vehicle.
• Transport speed is determined by the operator’s walking speed, typically around 4 km per hour.
• Up and downhill skidding can be done with sufficient safety on slopes of up to 35%.
• Typical performance rates at skidding distances of between 50 and 150 meters are approximately 2 to 4 tons per hour. Due to the high labor costs under European conditions, the maximum economically viable skidding distances are below 200 m.
• Machine costs include annual depreciation of the purchase price, operation and maintenance of about 400 hrs per year. These costs range from $US 3 to 8 per hour.
• The purchase costs for such machines range from US$ 11,000 to 14,000, which is prohibitively high for the rural community context of Southeast Asia.

A prototype of a mini-skidder is presently under construction at the Faculty of Mechanical Engineering, National University of Laos, Vientiane. Field trials on the machine are expected to commence towards the end of 2006. The prototype uses a 14 hp Yanmar engine and gearbox. The undercarriage consists of six 14-inch-diameter truck wheels and rubber belts with a circumference of 2 m, cut from used excavator or truck tyres of about 1.1 m diameter. The mini-skidder will be designed in a way that the engine is interchangeable with the standard two wheel agricultural tractor and other local agricultural devices. For safety reasons the operator will walk sideways in front of the skidder and control speed, direction and breaks via a handlebar. The skidder will have a clamp bank loading device allowing the dragging of stems or bamboo culms of up to 15 m in length. It is estimated that the undercarriage, control handle bar and loading device can be locally manufactured at a cost of around US$800 to US$1000, thereby totalling about US$2200, a price range affordable to cooperative forest user groups.

• The machine costs are estimated at around $US 9 per day, which is slightly higher than the costs of the 2-wheel tractor, especially due to the wear on the undercarriage, wheels and tracks.
• The costs for harvesting and forwarding bamboo (or timber of equivalent dimensions) on slopes below 30% are estimated in relation to distance according to Table 2. The table assumes a harvesting team of two persons for felling and forwarding to the skidding trail and one person for the operation of the mini-skidder. The daily wages are set at $US 2 per day per person.

The three methods of skidding operations are compared in Figure 1. The following table presents the cost estimates for current manual practices, horse logging and the proposed mini-skidder. For each of the systems an annual operation time of 100 days is assumed. This relatively low figure is due to two main factors: (1) harvesting operations will be restricted to the dry season of only 8 months and (2) due to employment in subsistence agriculture, availability of labour for forestry operations will be rather limited in the target areas.

Lux, M., 2005. On-site processing of timber as a key technology. GFA, Hamburg, Germany, Accessed at www.gfa-group.de