The effects of artificial ammonium enhancement on riverine periphytic diatom communities

摘要: An experiment to ascertain the influence of artificially enhanced ammonium concentrations on riverine periphytic diatom communities was conducted during an 80 day period in winter 1988/89 (temperature: 5°C). During initial 47 enrichment phase, chloride at different added O2-saturated river water experimental channels. Compared a control, addition 1.2 mg NH 4 + -N·l−1 resulted only slight changes species composition community. The 5.1 and more (≥60 µg NH3-N·l−1) decrease biomass drastic change composition. After 42 period, speciesFragilaria capucina var.vaucheriae, Navicula saprophila, atomus andGomphonema parvulum, all which are known be tolerant organic pollution, were found with relative abundances 44.8%, 35.6%, 2.3% 1.5%, respectively. Changes occurred within first two weeks subsequent recovery phase. month recovery, exhibited high degree structural similarity control.