EN
Forming of site index class of Scots pine (Pinus sylvestris L.) stands in relation to forest site types (including their moisture variants) and soil units (type/subtype and also – in minor extent – geological genesis of soil parent material) was investigated. The research was conducted in the Bolesławiec, Głogów and Oława forest districts (SW Poland) in 348 Scots pine stands. The values of the pine site index got higher with increasing fertility of soil units and better forest site type, but only when plots of sandy soils where concerned. Site index was found to differ significantly between fresh than moisture forest sites and soil units. The study results demonstrated that on fresh soils of sandy texture site index of Scots pine was distinctly related even to minor differences of site properties that concerned both its moisture and fertility. Scots pine, by height growth, does not fully utilize the great nutrient retention of fine textured soils that concerned both fresh and moisture pedons. Fine textured soils should be designed for eutrophic broadleaved tree species planting only, which would enable to fully utilize the trophic potential of such soils. The relation between the site index and geological genesis of sand forming parent material of soils was found. The differences in pine growth on sands of other genesis were assumed to be a result of different sorting and mineral composition of these materials.