Indexed on: 01 Sep '92Published on: 01 Sep '92Published in: Hydrobiologia
The cycling of dissolved reactive silicate (DRS) and sedimentary biogenic SiO2 has been examined in ultraoligotrophic Toolik Lake, Alaska. Watershed output of DRS (∼ 7 mmol m − 2 yr −1) is similar to other arctic study sites, but a short water residence time results in the poor retention of DRS (∼17%) within the lake. Biogenic SiO2 concentrations in surficial sediments average 123 mg g−1 with the highest concentrations arising from the production of benthic diatoms in the littoral zone. Lake water DRS concentrations are highest prior to spring flow and photic zone concentrations exceed 23 µmol 1−1 at the time of greatest primary production. Wintertime increases in watercolumn DRS concentrations and spring and summer pore water DRS flux estimates indicate that internal cycling within the lake may supply an amount of DRS equivalent to that which biologically utilized.