Unit costs of forest seedling production in the State Forests National Forest Holding

Seedling production in forest nurseries constitutes a fundamental component of forest management, determining the implementation of reforestation and afforestation as well as influencing the quality of future forest stands. The aim of the study was to analyse unit seedling production costs of major forest−forming species in the State Forests National Forest Holding (Poland) and to assess their variation depending on production technology, species, and regional conditions. The study was based on accounting data from the State Forests Information System (SILP) for the years 2020−2024, and costs were calculated using the full−cost accumulation (process costing) method. Statistical significance of differences was assessed using the Kruskal−Wallis test with Dunn’s post−hoc comparisons. The results indicate significant variation in unit production costs depending on the applied production technology. The highest costs were recorded in containerized production, while the lowest occurred in bare−root (field) production; tunnel production was characterized by the greatest variability. Production costs also differed by species, with the highest values observed for oak and beech and the lowest for pine. In most cases, an increase in production costs was observed over the period 2020−2024. In several comparisons, production technology significantly differentiated cost levels, whereas in containerized production a higher degree of cost standardization among species was observed. Regional analysis revealed variability in production costs among Regional Directorates of the State Forests. These differences were not statistically significant in the bare−root system, whereas significant regional differences were identified in the container system. The results confirm that unit seedling production costs are primarily determined by production technology and species, while regional variation is more pronounced in container production.