Economic and environmental performances of foresty mechanization: an innovative approach

Selecting the most suitable machines for forestry operations (FO) is crucial to evaluate the economic (Peco) and the environmental (Penv) performances of the whole forestry machinery chain (FMC). Nevertheless, there is still a lack of a generalized method to make this selection feasible. To fill this gap, an innovative approach based on two linked models operating at the forest stand level was developed to support the stakeholders, such as Local Authorities (e.g. mountain communities, municipalities) and supply chain operators (e.g. logging companies), in awarding public grants/subsidies and setting transparent FO tariffs, respectively. In the first model (FOREstry MAchinery chain selection, FOREMA v1) the feasible FMCs are defined by combining the categories that compose seven technical parameters (i.e.: stand’s management, commercial woody assortment, harvesting system, mechanization level, forest roads transitability, stand’s accessibility, mass of harvested wood). For each FMC, the model defines the FOs sequence and the types of usable machines. Through a second model (ENVironmental Inventory of Agricultural Machinery operations, ENVIAM v3), the mechanical parameters of the selected machines are uploaded from a machinery database, and Peco and Penv of each FO are computed. Peco (€∙h-1) are subdivided into: (i) fixed costs (financial depreciation, insurance and permanent workers) and (ii) variable costs (maintenance, total consuming inputs and temporary workers). Penv (kg∙h-1) are subdivided into: (i) total consuming inputs (fuel, lubricant, AdBlue®), (ii) partial consuming inputs (FM required materials for production, maintenance&repair work), (iii) exhaust gases emissions into the atmosphere (i.c. Diesel engines) and (iv) heavy metals released into the soil (tire abrasion). The simultaneous calculation of Peco and Penv allows to better define the sustainability of the selected forestry machinery chain.