Nowe stanowiska Didymosphenia geminata w Ropie i Białej Tarnowskiej (Polska Południowa)

W latach 2010-2011 badano zbiorowiska okrzemek w wodach Białej Tarnowskiej i Ropy. Stwierdzono obecność Didymosphenia geminata (Lyngbe) M. Schmidt na nowych stanowiskach na terenie Polski południowej. Na terenie Europy do niedawna występowała bardzo rzadko, zwłaszcza w zimnych, oligotroficznych wodach w górnych biegach potoków. Pojedyncze okazy tego gatunku występują w rzekach - Ropie i Białej. W sezonie wiosennym obserwowano go licznie w rzece Ropie poniżej zbiornika zaporowego "Klimkówka", gdzie tworzył maty i galaretowate styliki.

Studied territory involved two rivers: the Ropa River and the Biała River, both having its sources in the Low Beskid. The Ropa River is the biggest left-bank inflow of the Wisłoka River, running on its all length through two mesoregions (the Low Beskid and the Gorlickie Depression, few geographical regions and two Provinces (the Małopolska Province and the Podkarpacie Province). The valley of the Biała Tarnowska River is the right-bank inflow of the Dunajec River, which spreads through the Central Beskidian Piedmont. Materials to researches were taken in 2010-2011, from waters of the Biała Tarnowska River and the Ropa River. The aim of the work was to indicate new studying posts on both rivers, on which the existence of D. geminata was stated and to carry out a taxonomic analysis of populations with a determination of environmental conditions in studied liquids. Didymosphenia geminata was stated in all studying post with an exception of the last one located on the Biała River. It existed in forms of individual specimen, mainly on rocks. It formed bigger populations only on the Ropa River below the dammed reservoir "Klimkówka" - was observed on stalks in the Spring and Autumn seasons, it also formed mats in the Spring season.