Harvesting systems

Abstract

Forest harvesting refers to cutting and delivering trees in a productive, save, economic, and ecological process. It includes the conversion of trees into merchantable raw material according to specific industrial or individual requirements and needs. The combination of different technologies, machines, and labor force of the single processing steps of a harvesting operation to a harmonic and efficient production chain is the big challenge of a productive harvesting system. Wood harvesting has become an important science and operational factor all over the world in the last decades. In the framework of sustainable forest management, it is one of the key issues where the human impact on using natural resources like forest ecosystems can be reduced. Specifically in tropical countries, the forest ecosystems are very sensitive to any kind of human intervention. In native tropical forest as well as in tropical and subtropical forest plantations, the principles of reduced impact logging (RIL) are regarded as the most critical factor for economic, ecologic, and social sustainability (FAO 2004). Most of the negative image of tropical forest management comes from inappropriate harvesting methods with catastrophic environmental impact. Conventional logging systems (CL) did not take into consideration any sustainability matter, since the objective was always to make fast money and move on to the next exploitation site. In a long-term careful planning, harvesting operations can reduce costs, avoid environmental degradation, improve the utilization of the natural resources, and prevent the injury to personnel. Selecting the most appropriated harvesting system for a given silvicultural management system, terrain and climate condition, available infrastructure and transport system, technological and social restrictions, and finally available financial resources is a key decision in every wood-producing forest enterprise. The harvesting system contributes in a high proportion to the profitability of the wood production and therefore the costs of the raw material provided to the wood industry. For selecting the most adequate harvesting system, not only the investment costs for machines, training of personnel or staff, as well as maintenance costs should be considered. The important question for harvesting is how much does the cubic meter of wood loaded on the truck in the forest cost. In a broader sense, the total costs of the raw material put in the log yard of the respective wood industry crucial to take the decision of the best harvesting and transport system. The performance and productivity of the system as well as long-term factors like environmental degradation of forest production sites determine if the harvesting operations are conducted with an appropriate system or not. The number of wood-harvesting machines and technologies available at a global level is extremely high, multiplying by the options of putting the single processing steps lead to numberless combinations. The article pretends to classify harvesting systems from different points of view and to present some of the most frequently applied harvesting systems in the tropics on a global level. Since the innovation in harvesting technologies and equipment is very high, new systems and combination of single processing steps are found in harvesting practice every year.