As a consequence of immission calamity, large deforested areas had to be reforested in the Ore Mountains, on more then 30,000 ha. On almost 4,400 ha of the forest area, the bulldozer site preparation was used, applying heavy machinery at plot preparation, planting and care for new plantations. Removal of the surface humus represented, in respective site conditions, lethal site devastation and has prevented successful growth and development of tree plantings due to the key role of the humus forms. Restoration of the humus form compartment of the forest ecosystem represents the dominant factor in the revitalisation of functioning forest ecosystems in the area of interest. This presented paper documents the results of 20-years of development of forest soil on a bulldozed plot, where blue (Colorado) spruce (Picea pungens) was planted and birch (Betula verrucosa) was sown. The experiment was established in 1984. The study plot is located on the flat top part of the mountain range, at an altitude of 860 m a.s.l.; bedrock is formed by acid metamorphites (micaschist), and soil type is represented by Cryptopodzols – Podzols. Results confirmed a favourable role of the birch in the new humus form accumulation, and its chemical characteristics (pH, soil adsorption complex, nutrient content and amount). Also the dynamics of heavy metals and trace elements showed the remarkable effects of the humus layer accumulation and transformation.