The forest ecosystem is subject to biological, ecological and socio-economical factors that can negatively affect its quality. The diploma work presents the current knowledge of the experience of using wood biomass from energy recovery and the use of wood ash (combustion waste) as a forest fertilizer that has been reusable on an experimental surface in Spruce forest. In the experimental part of the diploma work, the results of the specified nutrition Ca, Mg, K and P and the potentially toxic metals Mn, Cu, Zn, Cr, Cd, and Pb in forest soil samples are evaluated. The application of wood ash has ensured the enrichment of forest soil by these elements that have been deficit-deficiency in these soils before application of the wood ash. The most increased calcium content compared to Mg, P and K. In the monitoring period 2012 – 2017, a gradual reduction in the concentration of these monitored elements has occurred. The most significant changes were in humus and in soil taken from the layer at a depth of 10 – 15 cm. The concentrations of the potentially toxic metals Mn, Cu, Zn, Cr, Cd and Pb in the samples of forest soils from the control and experimental area were low and were not mobilized in the soil. A one-time application of the wood ash used in this experiment has continued to persist. From the results of specified macroelements and potentially toxic metals monitored on the experimental surface and compared to the control area, the possibility to increase the applied dose of wood ash and to revise the time interval of the repetition of this application. The results obtained from the monitoring period show this fact. The increased consumption of wood ash using as a forest fertilizer is also acceptable due to the recovery of wood ash, which is currently still largely landfilled.