Role of Soil Algae on the Initial Stages of Soil Formation in Sandy Polluted Areas

Research to evaluate the role of the soil algae in the initiation of pedogenesis in sandy areas and to establish the mineral, chemical and organic composition of soil-algal crusts was done. The investigations area is located in southern Poland in a landscape of drift sand (Bledowska Desert) formed as a result of medieval deforestation related to Ag, Pb and Fe mining activities. Fifteen species of algae (Cyanophyta, Chlorophyta and Heterokontophyta) were identified. In the soil-algal crusts, C_org contents ranged from 0.35-2.23%, P_avail from 9-34 mg · kg⁻¹ and Nt was variable. In investigated area the ground on which soil algae developed was acidic (pH 4.4-5.7 in KCl). Among mineral components in the crust, phases rich in Fe and K dominated (776.5(±2.3) - 2803(±31) mg · kg⁻¹ and 230.5(±3.7) - 696(±22) mg · kg⁻¹, respectively) and elevated concentrations of Zn, Mn and Pb occurred. Soil-crust organic matter includes aliphatic and aromatic compounds, carbohydrate derivatives, phenols, furan and pyrene structures. N compounds have significant contribution in composition of soil-algal crusts - the algae are main source of organic matter in this stage of soil formation. It could accelerate the regeneration of disturbed ecological systems.