Acta Scientiarum Polonorum
Silvarum Colendarum Ratio et Industria Lignaria

The aim of the study is to identify the level, structure and rate of changes of costs incurred for crops tending and to assess their differentiation depending on the forest habitat type and age of crop.For the study, 30 plots were randomly selected, which were located on three habitat types: fresh mixed coniferous forest (FMCF), fresh mixed broadleaved forest (FMBF) and fresh broadleaved forest (FBF).The structure and dynamics of total crops forest tending costs were analyzed. The area and repeatability factor of tending operations  were determined. Unit costs of tending operations and unit costs of forest crops tending up to the 6th year of crop were determined. The variability index (V) was used to study the differentiation of unit costs of forest crops tending in relation to the forest habitat type and crop age. The conducted research confirmed an upward trend in unit costs of tending with the increase in habitat fertility and their decrease with the growing age of crop. Compared to the areas located in the FMCF,  the total unit cost of crop tending in the FMBF was higher by 130%, and in comparison of FBF the difference was 151%. The differentiation of the unit costs of crops tending  in relation to the forest habitat type and crop age was influenced by the the repeatability factor of tending operations and  unit costs of tending operations.  Costs of tending operations in FMBF were higher by 21%, and in FBF by 23%, than in FMCF. This differentiation was confirmed by the high values of the V variability index (FMCF: V = 82.9%, FMBF: V= 59% and FBF: V= 55%). The research also confirmed the variability of costs depending on the age of crop. The greatest changes being the cost on forest crops in the sixth year, where the V index indicated a very strong (FMCF: V = 175.8%, FMBF: V = 101.7%) and strong variability (FBF: V = 84%).