Macro- and Trace Elements in Freshwater Lake Sediments in the South of West Siberia

Abstract

Aim: Recently lake sediments and their studies have been drawing increasing attention due to organic farming and environmental engineering. This pilot study was carried out to examine chemical element content in sediments of several shallow freshwater lakes in the forest-steppe zone in the south of West Siberia, Russia. Study Design: Lake bottom sediments were collected at random by corer at 5-cm increments down to 75 cm deep, then stored at field moisture in anaerobic conditions at +4°C until analysed.   Place and Duration of Study: Institute of Soil Science and Agrochemistry and Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia, between June 2013 and September 2014. Methodology: Sediments of shallow freshwater lakes were studied by measuring macro- and trace elements contents and performing principal components analysis with the data obtained. Results: The studied lakes were found to store substantial amounts of carbon and nitrogen in their sediment organic matter, namely 2.2 Tg C and 0.2 Tg N in the top 40-cm layer. The PCA analysis of the elemental composition of lake sediments discriminated them from each other, revealing the unique biogeochemical nature of lake sediments even within one and the same biome. Conclusion: The estimates underscore the importance of lake sediments in the carbon budget of the Novosibirsk region and West Siberia with ca. 3,000 and 22,000 lakes, respectively. Unique chemical nature of lake sediments questions their potential as fertilizer and soil conditioners in agriculture and bioremediation, requires standardization and development of the adequate technologies.