Productivity and cost of harvesting roadside brushwood and small trees in Sweden: a simulation study

Abstract

ABSTRACT There is a large biomass potential in harvesting brushwood and young trees on roadsides in Sweden (about 3 PJ yr−1). In this study, a simulation model for analyzing time consumption and profitability of strip-harvesting brushwood and young trees under different conditions was developed and validated. A simple stand generator was used to generate twenty-nine stand types with an average diameter at breast height (DBH) ranging from 4–10 cm and stand density from 2,500 to 20,000 stems ha−1. Thereafter, harvest of these stands was simulated and analyzed. The results showed a positive correlation between harvester performance, DBH, and stand density. At approx. 10,000 stems ha−1, however, the performance flattened out. There was a clear relationship between costs and the number of stems felled. In contrast, the cost per tonne of dry matter was governed by a combination of tree size and number of trees felled (lowest cost when felling many thicker stems and vice versa). It was concluded that this simulation model, using data that was quite easy to obtain, can address one of the main challenges for brushwood harvesting, i.e. identifying areas where operations will be profitable.