SPECIES COMPOSITION EFFECTS OF FOREST STANDS ON AFFORESTED AGRICULTURAL LAND ON THE SOIL PROPERTIES

Afforestation of agricultural lands took place on different sites and ecological conditions, including lower and medium elevated localities, and continues to present. On the other side, low attention is paid to ongoing soil changes. The study is aiming to fill this gap and documents effects of species composition in stands of Scots pine (Pinus sylvestris), Norway spruce (Picea abies), birch (Betula verrucosa) and Douglas fir (Pseudotsuga menziesii). These stands are in the territory of the School Training Forest Kostelec nad Černými lesy, in the altitude 430 m a.s.l., on the site of forest type 4Q1. The plots were compared with the neighboring locality with arable land. During the first roughly 40 years, considerable changes were documented on the afforested plots. The surface humus layers in the coniferous stands were formed, fixing relatively high amounts of carbon. Also the favorable effects on the upper mineral horizons were observed, consisting in the shifts of the soil physical characteristics and in the increased sequestration of carbon. Afforestation increased the carbon fixation not only due to stand biomass and litter necromass accumulation, but also due to increased sequestration in the upper mineral soil