Enzymatic activity of soils and soil organic matter stabilization as an effect of components released from the decomposition of litter

Abstract

The processes associated with litter decomposition are closely related to nutrient circulation in forest ecosystems. This study attempted to determine the role of nutrients, especially C and N, released by the decomposition of litter of different tree species in enzymatic activity and soil organic matter stabilization. In the study, we attempted to exclude the influence of soil properties, especially texture, on enzymatic activity and soil organic matter stabilization. Four areas covered by ash (Fraxinus excelsior L.), oak (Quercus robur L.), beech (Fagus sylvatica L.) and pine (Pinus sylvestris L.) stands were selected. Throughout the study period, the litter properties of four tree species and the chemical composition of the filtrate released during litter decomposition were determined. The activity of enzymes involved in C, N, P and S cycles, as well as soil organic matter fractions, were recorded. The activity of the enzymes was determined specifically by the carbon substrates released during the process of litter decomposition. A strong correlation between enzymatic activity and the amount of dissolved organic carbon (DOC) released from the decomposing litter was demonstrated. The effect of tree species could be observed in the amount of carbon and nitrogen of the light and heavy fractions of soil organic matter. The lowest C/N ratio in all fractions of organic matter was determined for ash stand soils that were characterized by having the highest amount of the heavy fraction of soil organic matter.