Seasonality of chlorophyll and nutrients in Lake Erken – effects of weather conditions
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The seasonality of nutrients and chlorophyll a in Lake Erken (Sweden) was monitored during 1994 to 2001 (warm period) and compared to the time period 1975 to 1979 (cold period). The coupling to weather conditions and potentially influencing factors, such as water temperature, light conditions, and stratification were evaluated. During the warm period the ice cover period was considerably shorter and the ice breakup about one month earlier than in the cold period. The decrease in thickness and duration of snow cover resulted in considerably better light conditions during winter, favouring phytoplankton growth under the ice. The nitrate concentrations were much lower in late winter during the warm period. There were elevated phosphate and ammonium concentrations in the hypolimnion during August. Significantly higher phosphate and chlorophyll a levels were noticed in autumn during the warm period, compared to the cold period.
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- Ahlgren, I. & G. Ahlgren, 1976. Analytical methods for water chemistry. Institute of Limnology, Uppsala University: 80 pp.Google Scholar
- Carvalho, L. & A. Kirika, 2003. Changes in shallow lake functioning: Response to climate change and nutrient reduction. Hydrobiologia 506–509: 789–796.Google Scholar
- Kamp-Nielsen, L., 1975. A kinetic approach to the aerobic sediment–water exchange of phosphorus in Lake Esrom. Ecol. Modell. 1: 153–160.Google Scholar
- Mortimer, C. H., 1941. The exchange of dissolved substances between mud and water in lakes I. J. Ecol. 29: 280–329.Google Scholar
- Mortimer, C. H., 1942. The exchange of dissolved substances between mud and water in lakes II. J. Ecol. 30: 147–201.Google Scholar
- Nõges, T., P. Nõges & R. Laugaste, 2003. Water level as mediator between climate change and phytoplankton composition in a large shallow temperate lake. Hydrobiologia 506–509: 257–263.Google Scholar
- Pettersson, K., 1980. Alkaline phosphatase activity and algal surpluslinebreak phosphorus as phosphorus-deficiency indicators in Lake Erken. Arch. Hydrobiol. 89: 54–87.Google Scholar
- Rydin, E. & A.-K. Brunberg, 1998. Seasonal dynamics of phosphorus in Lake Erken surface sediments. Arch. Hydrobiol. Spec. Issues Adv. Limnol. 51: 157–167.Google Scholar
- Pierson, D. & G. A. Weyhenmeyer, 1994. High resolution measurements of sediment resuspension above an accumulation bottom in a stratified lake. Hydrobiologia 284: 43–57.Google Scholar
- Törnblom, E. & K. Pettersson, 1998. Bacterial production and total sediment metabolism in profundal Lake Erken sediments. Arch. Hydrobiol. Spec. Issues Adv. Limnol. 51: 177–183.Google Scholar
- Törnblom, E. & E. Rydin, 1998. Bacterial and phosphorus dynamics in profundal Lake Erken sediments following the deposition of diatoms: a laboratory study. Hydrobiologia 364: 55–63.Google Scholar
- Vrede, K., 1997. Bacterioplankton production and biomass in two lakes of different trophic status. Acta Universitatis Upsaliensis 282: 33 pp.Google Scholar