What are the operational challenges and costs for forestry forwarders under different site conditions in Southern Bahia, Northeastern Brazil?

The Brazilian planted forest sector plays a vital role in economic and environmental sustainability, favouring mechanisation to meet market demands. However, studies addressing operational performance in the northeastern region remain scarce, particularly under varying site and stand conditions. Moreover, there is a lack of predictive models that link forestry forwarder productivity to operational costs and extraction strategies adapted to local site variability. It is noteworthy that forest extraction in Brazil faces challenges due to the variability of edaphoclimatic conditions, impacting forestry forwarder productivity and operational costs. This study aimed to evaluate how specific operational factors (such as extraction distance, forestry forwarder load capacity, forest productivity, and time allocation within the machine's operational cycle) influence the efficiency and costs of timber extraction. Field data were collected in southern Bahia, a strategic area for the pulp and paper industry, across stands with distinct productivity levels and forest rotations. Time and motion studies, linear regression, and cost analysis revealed that predictive models explained up to 92% of forestry forwarder productivity. A strong inverse correlation was found between productivity and extraction distance. This result highlights the importance of minimising long hauls to reduce costs. Productivity was directly proportional to forest yield, with the forestry forwarder loading process representing up to 42% of the operational cycle. The use of higher-capacity forestry forwarders has optimised extraction, with an average of 21 m³ per trip. Cost analysis showed a 26% increase in cost per cubic metre with decreased forest yield and a 61% increase with longer extraction distances. These findings define optimal operational parameters for Southern Bahia, Northeastern Brazil, emphasising cost-efficiency and performance improvements.