Machinery and equipment in harvesting

Abstract

Forest harvesting is one of the most important and cost-intensive operations in forest management. The different process steps of harvesting operations are felling, delimbing, debarking, bucking, off-road transport of the wood, and loading. Specifically in tropical countries, the resources, equipment, and machines that can be used are manifold and can be composed in complex systems. The climate conditions, soil properties, and human resources have to be considered in the choice of the equipment or machine used in each single process step of harvesting operations. Many tropical countries are even today facing a lack of financial resources for using their forests in a competitive and sustainable way. Harvesting in native tropical forests faces the following problems: trees of big dimension, low volume per ha, diversified assortments in species, length and diameter, sensitive soils where no mechanical or chemical corrections are possible, many environmental restrictions, and difficult access. The financial situation, technical know-how, and machine availability have impact on the volume and assortments that can be produced in harvesting operations. Logging companies with better financial background are able to mechanize many harvesting processes and increase productivity and working safety this way. They are able to create a net of forest roads to facilitate forest operations and to use adequate machines and equipment that allow also to extract big and heavy logs of high value. Smallholders or communities on the other hand are still relying on simple tools and equipment, animal-assisted skidding, and manual or motor-manual work in wood harvesting operations. In general they face strict limitations concerning the size of the trees that can be felled and the logs that can be skidded. In tropical forest plantations, the conditions found are quite different. In general only one or two species are planted, the stands are homogeneous in height and diameter, dimensions of the trees are smaller, the forest is planned and provides good access, and high volumes per hectare are harvested in clear-cut systems. All these utilization conditions are favorable to a higher degree of mechanization, since the economic returns are higher and faster in short rotation plantations. Smaller properties as well as industrial plantation owner work with adapted agricultural tractors or specific forestry machines, which allow high productivity with acceptable environmental impact. The present chapter gives an overview on the existing methods, equipment, and machines that are available for harvesting operations in tropical countries. It focuses on the description of the use and suitability of the equipment for the different process steps of harvesting operations. The permanent technical innovation in the sector makes it difficult to present always the technical specification of the newest existing machines on the markets. Detailed information about chainsaws, harvester, forwarder, skidder, feller buncher, loader, and additional tools available for harvesting operations should always be evaluated in the respective country for the specific working conditions.