cyanobacteria and cyanotoxins the influence of nitrogen versus phosphorus蓝藻和微囊藻毒素的氮和磷的影响.pdf

Cyanobacteria and Cyanotoxins: The Influence of Nitrogen versus Phosphorus 1 ¨ 1 2 3 4 Andrew M. Dolman *, Jacqueline Rucker , Frances R. Pick , Jutta Fastner , Thomas Rohrlack , Ute Mischke5, Claudia Wiedner1 1 Chair of Freshwater Conservation, Brandenburg University of Technology, Bad Saarow, Germany, 2 Department of Biology, University of Ottawa, Ottawa, Canada, ˚ 3 Federal Environmental Agency, Berlin, Germany, 4 Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, As, Norway, 5 Department of Shallow Lakes and Lowland Rivers, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany Abstract The importance of nitrogen (N) versus phosphorus (P) in explaining total cyanobacterial biovolume, the biovolume of specific cyanobacterial taxa, and the incidence of cyanotoxins was determined for 102 north German lakes, using methods to separate the effects of joint variation in N and P concentration from those of differential variation in N versus P. While the positive relationship between total cyanobacteria biovolume and P concentration disappeared at high P concentrations, cyanobacteria biovolume increased continually with N concentration, indicating potential N limitation in highly P enriched lakes. The biovolumes of all cyanobacterial taxa were higher in lakes with above average joint NP concentrations, although the relative biovolumes of some Nostocales were higher in less enriched lakes. Taxa were found to have diverse responses to differential N versus P concentration, and the differences between taxa were not consistent with