Concentrations of phosphate phosphorus and total phosphorus in the water in different biotopes of the Nature Reserve Alúvium Žitavy

Abstract

Over the years 2006-2008 the concentrations of P-PO₄^3- and PTot. were evaluated as dependent on the time and site of sampling in the water of the Nature Reserve (NR) Alúvium Žitavy which is situated in the southwestern part of the Slovak Republic. According to the results obtained, we can calculate the concentration of phosphate phosphorus over the whole monitored period in water of the Nature Reserve was 0.44 mg dm-3. It represented 60.27% of total phosphorus, other forms of phosphorus represented the rest of total phosphorus. Dependent on the sampling site we found out the highest mean P-PO₄^3- concentrations over the whole monitored period in summer with the maximum being in August and the lowest in February and March. As dependent on the sampling site mean P-PO₄^3- concentrations slightly decreased from the first to the last sampling site. We found out statistically significant influence of all three qualitative factors (sampling year, sampling month, sampling site) in value changes of this form of phosphorus by analysis of variance. The total phosphorus over the whole monitored period was 0.73 mg dm-3. Generally, the lowest mean values over the whole monitored period were in the winter season with minimum being in February. Absolutely, the lowest mean PTot. concentration was measured in this month in 2008. Analogous to P-PO₄^3-, mean PTot. concentrations in the water generally slightly decreased from the first to the last sampling site. Influence of sampling site was also confirmed statistically. That finding demonstrates the purifying ability of wetland habitats being situated in the nature reserve.