LAUSR

The aim of this research was the analysis of the species composition and planktonic algae biomass in the ponds of Habsburg Park in Żywiec. So far, the urban park ponds have been rarely studied (especially in Poland) in this respect. The analyses of the park ponds water in Żywiec were conducted during the vegetation season in 2016, in monthly intervals. The phytoplankton biomass was calculated by comparing the shape of algae to geometrical figures and based on the chlorophyll a concentrations. The chlorophyll a concentrations and values of the planktonic algae biomass remained at a low level. The species composition showed the dominance of diatoms (i.a. Achnanthes lanceolate (Brébisson ex Kützing) Grun. in Cl. & Grun., Encyonema sp. (Kützing) Krammer). The highest values of the planktonic algae biomass were observed in the summer season. The ponds in the Habsburgs Park in Żywiec have great aesthetic and recreational values and therefore more frequent monitoring is necessary.