Contribution
Nitrogen fixation, ammonium and nitrate uptake during a bloom of Cylindrospermopsis raciborskii in Lake Balaton
Présing, Mátyás; Herodek, Sándor; Vörös, Lajos; Kóbor, István
Archiv für Hydrobiologie Volume 136 Number 4 (1996), p. 553 - 562
34 références bibliographiques
publié: Jun 10, 1996
DOI: 10.1127/archiv-hydrobiol/136/1996/553
ArtNo. ESP141013604006, Prix: 29.00 €
Abstract
N2-fixation and 15N-labelled ammonium and nitrate uptake were measured during a bloom of C. raciborskii in two basins of Lake Balaton. In the eastern basin when the chlorophyll-a content reached 70 µg/l the N2-fixation was low (59 mg N m-2 day-1) and the N uptake was dominated by ammonium (393 mg N m-2 day-1). The nitrate uptake was of minor importance in both basins (43 and 55 mg N m-2 day- respectively). In the western basin, the chlorophyll-a content was 160 µg/l and recirculation of regenerated forms of nitrogen could not support the demand. Although the ammonium uptake was high (357mg N m-2day-1), the fixed nitrogen (407mg N m-2day-1) exceeded it. The daily integrated carbon and nitrogen uptake ratios were 5.2 (weight/weight) in both basins.
Mots-clefs
ammonium • nitrate • chlorophyll-a • carbon • recirculation • Lake Balaton • Hungary