Review Article Silicon pools and fluxes in soils and landscapes—a review

Silicon (Si) is the second-most abundant element in the earth’s crust. In the pedosphere, however, huge spans of Si contents occur mainly caused by Si redistribution in soil pro-files and landscapes. Here, we summarize the current knowl-edge on the different pools and fluxes of Si in soils and terres-trial biogeosystems. Weathering and subsequent release of soluble Si may lead to (1) secondarily bound Si in newly formed Al silicates, (2) amorphous silica precipitation on sur-faces of other minerals, (3) plant uptake, formation of phyto-genic Si, and subsequent retranslocation to soils, (4) translo-cation within soil profiles and formation of new horizons, or (5) translocation out of soils (desilication). The research car-ried out hitherto focused on the participation of Si in weather-ing processes, especially in clay neoformation, buffering mechanisms for acids in soils or chemical denudation of land-