Role of phosphorus and nitrogen for bacteria and phytopankton development in a large shallow lake

摘要: Nutrient (P and N) enrichment experiments in small enclosures (20 l) were carried out to determine P and/or N limitation of bacterioplankton Lake Vortsjarv. The specific interest the study was test if it is possible detect nutrient `physiological' or growth (rate) competition for nutrients (N P) with phytoplankton generally rich lake. Thymidine leucine incorporation; aminopeptidase, β-D-glucosidase alkaline phosphatase activity, total count bacteria, chlorophyll a concentration primary production as well concentrations different chemical forms followed during 4–5 days experiment. To address question interactions between nutrients, bacterio- phytoplankton, experimental seasonal data sets included analyses. Phosphorus (P) had positive effect on enclosure June 1997; no effects found September 1996, while May affected mainly phytoplankton. On scale, development connected production, phosphorus temperature. In experiments, related productivity but importance bacterial grazers could be presumed. Thus, evidence P, rather depended organic food supply originating from