Charophytes (Characeae), macroscopic green algae, are one of the macrophytes occurring mainly in ... more Charophytes (Characeae), macroscopic green algae, are one of the macrophytes occurring mainly in the littoral zone of lakes. Their occurrence in a lake is considered as indicative of low trophy and high ecological status. Photosynthetic activity of charophytes leads to precipitation of autochthonous carbonates, that substantially contribute to lacustrine sedimentation. Calcified parts of their thalli can be preserved in sediments as thalli encrustations and calcified female fructifications called gyrogonites. The oldest charophyte fossils are Upper Silurian in age thus these macroalgae are a potential archive of palaeonvironmental information back to the middle Palaeozoic. Ability to recognize genera or even species of the fossil gyrogonites allows to use them as lacustrine biomarkers when contemporary ecological requirements of the taxa are known. Both gyrogonites and encrustations are frequently used in isotope investigations of lake sediments. However, in order to carry out correct, reliable palaeolimnological reconstructions using stable isotope record of the charophyte carbonates it is essential to know the relation between δ 13 C and δ 18 O of recent encrustations and gyrogonites and δ 13 C of DIC (dissolved inorganic carbon) and δ 18 O of ambient water, respectively. The main aim of the paper is to present the importance of charophytes in carbonate lacustrine sedimentation and to describe the possibilities to use their remains as biomarkers of current ecological state of lakes, potentially useful in palaeolimnological studies.
Charophytes (Characeae), macroscopic green algae, are one of the macrophytes occurring mainly in ... more Charophytes (Characeae), macroscopic green algae, are one of the macrophytes occurring mainly in the littoral zone of lakes. Their occurrence in a lake is considered as indicative of low trophy and high ecological status. Photosynthetic activity of charophytes leads to precipitation of autochthonous carbonates, that substantially contribute to lacustrine sedimentation. Calcified parts of their thalli can be preserved in sediments as thalli encrustations and calcified female fructifications called gyrogonites. The oldest charophyte fossils are Upper Silurian in age thus these macroalgae are a potential archive of palaeonvironmental information back to the middle Palaeozoic. Ability to recognize genera or even species of the fossil gyrogonites allows to use them as lacustrine biomarkers when contemporary ecological requirements of the taxa are known. Both gyrogonites and encrustations are frequently used in isotope investigations of lake sediments. However, in order to carry out correct, reliable palaeolimnological reconstructions using stable isotope record of the charophyte carbonates it is essential to know the relation between δ 13 C and δ 18 O of recent encrustations and gyrogonites and δ 13 C of DIC (dissolved inorganic carbon) and δ 18 O of ambient water, respectively. The main aim of the paper is to present the importance of charophytes in carbonate lacustrine sedimentation and to describe the possibilities to use their remains as biomarkers of current ecological state of lakes, potentially useful in palaeolimnological studies.
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Papers by Andrzej Pukacz