Abstrakt: |
Production and biomass values from phytoplankton populations in four different Swedish lakes were analysed. The production in all lakes was directly proportional to biomass during homothermal periods. When the lakes were stratified there was a strong negative relation between specific growth rate and biomass. The data fitted to a logistic density dependent growth equation of the form: dB/ dt = µmB(1-B · K−1) where B is the biomass, µm the maximum specific growth rate and K the carrying capacity. The equation was used to derive the parameters µ · µm−1 and carrying capacity (the maximum possible biomass). These parameters were then discussed in relation to light climate, phosphorus concentration and humic content. |