Main content area

Oxygen stable isotope composition of carbonate encrustations of two modern, widely distributed, morphologically different charophyte species

Pronin, Eugeniusz, Pełechaty, Mariusz, Apolinarska, Karina, Pukacz, Andrzej
Hydrobiologia 2018 v.809 no.1 pp. 41-52
Chara globularis, carbon, carbonates, climate, lacustrine sediments, lakes, oxygen, stable isotopes, Poland
Oxygen (δ¹⁸O) and carbon (δ¹³C) stable isotope analyses are among the standard methods applied in the studies of past environment, including climate. In lacustrine sediments, δ¹⁸O and δ¹³C values can be measured in various carbonates including charophyte encrustations. Application of the stable isotope record of lacustrine carbonates requires knowledge about the possibilities and limitations of the method. Thus, this study presents the oxygen stable isotope composition of carbonate encrustations precipitated by modern charophytes (δ¹⁸OCARB) and of ambient waters (δ¹⁸OWATER). The study objects were widely distributed and morphologically different charophyte species, large and branchy Chara tomentosa L. and small and slender Chara globularis Thuill. Each species was studied in five lakes located in western Poland, at three sites per lake. The study demonstrated that δ¹⁸OCARB values were similar for the two charophyte species and were lake-dependent. δ¹⁸OCARB and δ¹⁸OWATER relationships were also similar for the studied charophytes with carbonate encrustations ¹⁸O-depleted compared to ambient waters. The shift of mean δ¹⁸O values between C. tomentosa and C. globularis encrustations and ambient waters, 2‰ and 3.2‰, respectively, was evidenced in all studied lakes which may indicate potential applicability of δ¹⁸OCARB of the two species in paleolimnological studies.