Influence of mineral and bio oil on the germination of acorn and the growth of pedunculate oak (Quercus robur l.) seedlings

The purpose of this study is to research the effects of different concentrations of mineral and biodegradable lubricants for chainsaws upon seedling growth and the initial growth of pedunculate oak (Quercus robur L.), the most significant forest tree species in the region of the lowland Croatia. Tests were carried out in two nurseries upon 1-m2-plots (altogether 28 test plots and two control ones) by spilling biodegradable oil and mineral oil, each in three concentrations (0.1 l/m2, 0.2 l/m2, 0.5 l/m2). The analysis showed that the increased concentration of mineral oil may decrease seedling germination ; on the contrary, the bio-decomposable oil can increase it. Due to the insufficiently expressed dependence between the root collar diameter and the oil concentration, the analysis should include the research on other factors. Based on pedological research, we may conclude that the soil of weedy plots is biologically more active, which results in faster oil degradation