Forest road density in flat and sloping site conditions in Brazil

Abstract

ABSTRACT Forest road densities which are too high increase production costs, planting area loss, and environmental impacts. To solve this problem and plan an adequate forest road density, it is necessary to analyze and consider the topography, road network-related costs, and the type and number of machines to meet the required wood production. The aim of this study was to determine the current road density (RD), the optimal economic road density (ORD) and operational road density (OD) in flat and sloping site conditions for the full tree harvesting system in Southern Brazil. The RD was determined by the ratio of total road lengthand the total productive area. ORD was determined based on the transport geometry model, considering the minimization of the sum of unit costs of road construction and maintenance, loss of productive area, mitigation of road impacts, and wood extraction. The OD was determined considering the minimum number of extraction machines necessary to meet the annual demand for wood. All forest road densities were lower in flat site conditions than in sloping areas. In both conditions (flat and sloping), RDs (126 and 180 m ha−1, respectively) were higher than ORDs (53 and 65 m ha−1, respectively), which were lower than ODs (92 and 123 m ha−1, respectively). Therefore, OD can be an alternative parameter for managers to use in forest road network planning, mainly in conditions where ORD is not feasible to adopt.