Concentrations and fluxes of N species in precipitation (direct atmospheric bulk deposition on the lake surface), watershed export (via tributaries), and output from Plešné Lake in the 2011 hydrological year.

Uncertainty (±) of the fluxes was calculated using an error propagation method [27]. 1)Ammonium (NH4+), nitrate (NO3−), dissolved organic N (Norg), particulate organic N (PN = total Norg−Norg), and total nitrogen (TN = NH4++NO3−+Norg+PN). Concentrations of nitrite were <0.1 µmol L−1 and were neglected. 2)Change in storage represents the average change in amount of N species in the lake during study period and was based on differences between their concentrations at 0.5, 4, 9, 14, and 17 m depths on 31 October 2011 and 20 October 2010, and volumes of the respective water layers [21]. 3)Net in-lake production was calculated on an annual basis as described by Kopáček et al. [21] (production = output+change in storage−input by precipitation and tributaries), and then recalculated to daily fluxes given on a lake-area basis. Concentrations and fluxes of N species in precipitation (direct atmospheric bulk deposition on the lake surface), watershed export (via tributaries), and output from Plešné Lake in the 2011 hydrological year.