The role of two submerged macrophyte species (Ceratophyllum demersum and Potamogeton pectinatus) as biological factor affecting concentrations of P and chlorophyll a concentrations was tested under laboratory conditions. In general, after four weeks exposition, the significant reduction of TP, P-PO4 and chlorophyll a was observed in all experimental variants (aquaria with P. pectinatus, C. demersum and P. pecinatus + C. demersum), but the highest decrease of phosphorous compounds (TP, P-PO4) was noted in aquarium with C. demersum, whereas the highest decline of chlorophyll a concentration (biomass of phytoplankton) was observed in aquarium with C. demersum + P. pectinatus. Together with the reduction of chemical parameters the biomass of macrophytes as well mean length of plant shoots significantly increases. The highest growth of shoots and biomass showed C. demersum.
Due to the significant role of macrophytes in the functioning of lake ecosystems studies have been undertaken to examine whether mutual dependence is present within emergent, floating-leaved, and submerged aquatic macrophytes. The study included 5 small lakes from Polesie Lubelskie region. The research included: qualitative analysis of macrophytes (area occupied by macrophytes, composition, range of individual plant groups of occurrence), quantitative analysis of macrophytes (biomass of macrophytes inhabiting the lake), analysis of distribution as well as characteristics diversity of shoreline and surrounding land use. Because of differences in the environmental conditions, mostly light availability, usage of buffer zone, among the three macrophyte groups, changes in biomass were analyzed in this work suggests that complementarity not competition drive the community. This phenomenon seems to occur only in macrophyte lakes where all three groups are present and the surrounding buffer zones remain natural. In lakes where one of the three groups of macrophytes were missing, it is likely that the ecological roles are fulfilled by other plant groups, such as phytoplankton. The studied lakes represent both phytoplanton and macrophyte type of lakes.