Changes in phosphorus and silicon fluxes and pools at the sediment surface following an experimental spring bloom deposition

摘要

Both silicon (Si) and phosphate (P) can specifically adsorb to the surface of iron and aluminium oxides (Carritt Goodgal 1954, Gehlen Van Raaphorst 2002). Since (de)sorption is one of the main factors which regulate the availability of dissolved P in sediment under aerobic conditions (Jensen et al. 1995), competition by Si may influence the cycling of P in surface sediment (Hartikainen et al. 1996, Tuominen et al. 1998), e.g. after the deposition of a diatom-dominated spring bloom rich in easily released Si (Tallberg Koski-Vaehaelae 2001). In this study, the impact of the sedimentation of a diatom-dominated spring bloom on dissolved P and Si fluxes and pools was studied in a five-week flow-through laboratory experiment with the aid of a sedimentary P-fractionation scheme applied to both P and Si.