Silicon Load and the Development of Diatoms in Three River-Lake Systems in Countries Surrounding the Baltic Sea

• Published in: Hydrobiologia
• Main Authors: NOGES Peeter, NOGES Tiina, ADRIAN Rita, WEYHENMEYER Gesa
• Language: English
• Published: SPRINGER 2008
• Subjects: North Atlantic; North Atlantic oscillation
• Online Access: https://publications.jrc.ec.europa.eu/repository/handle/JRC35016; https://doi.org/10.1007/s10750-007-9194-y

We studied coherence in dissolved silicon loads from rivers into lakes, the development of diatoms in lakes, and the role of climatic forcing on the Si cycle in three river-lake systems in Sweden, Estonia, and Germany. We found coherent seasonality in the silicon loads of the two northern rivers, which was probably caused by the common snow type hydrology of the catchments as compared to the rain type hydrology of the catchment further south. The coherence of the studied Si-related variables between lakes was rather based on similarities in lake morphometry than on the climatic region. Among measured variables at the three sites, river water discharge responded most coherently to climatic forcing as synchronized by the North Atlantic Oscillation winter index (NAOw). Water discharge and Si load as strongly linked variables, showed coherent pattern among the river systems. We found significant seasonal specific correlations of the NAOw either with the biomass or the share of diatoms for each lake but no coherent pattern among the lakes. Our results indicate that water discharge driven processes are more coherent across regions than are lake-internal processes. JRC.H.5 - Rural, water and ecosystem resources