Changes in climate, atmospheric carbon dioxide concentration and disturbance regimes have been occurring for decades in the global boreal forest. Disturbances are an important factor influencing forest structure formation and changes in it. It is expected, that with future climate change the frequencies, intensities and severities of disturbances will change and with that also natural disturbance processes and the responses of ecosystems to disturbances. Fire is one of the most important natural disturbance in boreal forest. Forest fires and the recovery from there are important regional carbon storage because carbon lost in fires has a substantial contribution to regional carbon budgets. The main aim of the study is to evaluate the changes in the size and quality of soil carbon and nitrogen pools after forest fires. The topic is very timely since deeper understanding on soil carbon stocks and its underlying processes is urgently needed to fill our gaps of understanding on the ecosystem carbon cycle in the changing climate. Soil is the largest stock of organic carbon, but the related processes changing soil organic matter quality and its pool distribution are still poorly understood. Simulations with the model MicroForest, that combines a process based forest photosynthesis and growth model to below-ground processes such as: soil organic matter decomposition, turnover of carbon compounds of different chemical fractions, soil nitrogen/protein pools, root and rhizosphere respiration and exudation of recent photosynthates through roots, will be carried through and the simulation results will be compared to actual field measurements. With help of field measurements data the model will be improved.