Machine utilization rates, energy requirements and greenhouse gas emissions of forest road construction and maintenance in romanian mountain forests

Abstract

The FAO and EU forest strategies advocate the use of forest resources in ways which minimize the impact on the environment and climate. However, in forests with poor accessibility, the environmental footprint of forest operations is significant due to the long timber extraction distances. Thus, improving the environmental performance of forest operations requires a well-developed forest infrastructure, specifically the density and quality of roads. The aim of this paper was to assess the environmental footprint of forest roads in terms of embodied energy and greenhouse gas emissions due to construction and maintenance. In this respect, life cycle assessment approach was used to develop an input-output model for benchmarking two case study areas, considering real machine utilization rates, fuel consumption and labor requirements. The forest road life cycle was set to 30 years. Direct energy requirements derived from the fuel consumed by the machinery were considered. Construction and maintenance required energy inputs of 490.9 MJ m -1 and 580.4 MJ m -1 , respectively about 36.6 kg CO 2eq m -1 and 43.1 kg CO 2eq m -1 emission rates in the two case study areas, while occupying productive land with forest roads triggered a loss of 3.95 kg CO 2eq m -1 y -1 and 4.40 kg CO 2eq m -1 y -1 during the life cycle of the forest road. However, the CO 2eq loss due to road construction and maintenance is insignificant when compared to the CO 2eq stored in the growing stock of the opened forest area. Terrain characteristics showed a strong influence on the amount of fuel consumption, required energy input and GHG emissions, leading to higher environmental burden and higher road construction costs.