Revitalization and preservation of biodiversity. Focus on water bodies in the Cracow region

The studies included 2 water bodies in Cracow (Kraków), 6 water bodies in the commune of Zabierzów (Cracow County) and 4 in the commune of Niepołomice (Wieliczka County). The studies were carried out in June 2018 and May 2019. The ways on management of the water bodies were compared. Problems related to revitalization were identified. One of these problems is the preservation of biodiversity. In some cases revitalization reduces biodiversity. This can happen due to the liquidation or limitation of the reed bed zone. Such a situation was observed in the water bodied of Zelków and Karniowice (com. Zabierzów). Both have ornamental functions now. Removal of most of reed does not disturb mallards (Anas platyrhynchos), but makes it impossible to nest for other birds such as moorhen (Galinula chloropus). Moorhens were observed in two former fish ponds in Staniątki (com. Niepołomice) and in the pond of the Kaczeńcowa street. In one of them revitalization caused the diminishing of the water area, but did not change the character of the water body. Bird species were recorded at water bodies.