Stabilization of soil organic matter following the impact of selected tree species in temperate climate

The species composition of a forest stand has a significant impact on the biophysicochemical properties of soil. The aim of our research was to determine the relationship between the fractional composition of soil organic matter (SOM) and the composition of leachates from soil influenced by various tree species. In our research, we assumed that the fractions of SOM are strongly positively correlated with dissolved organic carbon (DOC), nitrogen and the ionic composition of leachates. Our study was conducted in a common garden experiment with eight different tree species. The research included the analysis of vertical variability in the composition of SOM fraction in relation to the leachates composition. The research covered the organic horizon (O), humus mineral horizon (A) and enrichment horizon (B). Our findings confirmed the differentiated impact of the studied tree species on the amount of light and the heavy fraction − mineral associated fraction of SOM. The species composition of the forest stand significantly influenced the amount of released DOC, as well as pH values and the content of selected cations and anions in the leachates from various genetic soil horizons. The amounts of C and N in the SOM fraction and the ionic composition of the leachates change with the depth. C and N of the labile and stable fractions were strongly positively correlated with the amount of DOC and N in the leachates. In order to initiate the stabilization of organic matter, it is worth using deciduous species such as Norway maple, sycamore maple and small-leaved lime. The results of our research may find practical application in planning the species composition of a tree stand, especially under changing climate conditions.