Algal biomass was examined on the soil surface and within the soil layer (0 30 cm) under two set a side lands: unmown and mown for the first time after 4 years. The research plots were located on soils of 4 different classes: clay loam, loamy sand, clayey sand and light sand.The relationships on the level P > 0.05 between algal biomass and soil tex-ture on the unmown set a side land were very weak. Lack of fertilization and ploughing caused deterioration of algae. On loamy sand and clayey sand algae changed location to more rich soils. Relationships between algal biomass and soil texture class under the mown set a side land were strong. Algal biomass was low on clay loam and on light sands. The soils of clay loam and light sand texture class were more intensively colonised by algae on the soil surface. However, algae from those soils formed one homogeneous group with algae on clayey sand. On the other hand the soil texture did not have an influence on crop of vascular plants. The differences in algal biomass and in crop of vascular plants between the two set a side lands show that plants win the competition ...
