The primary productivity of submerged macrophytes in West Blue Lake, Manitoba

摘要

The productivity ofPotamogeton Richardsonii, P. pectinatus, Myriophyllum alterniflorum, Megalodonta Beckii, andChara vulgarisin West Blue Lake, Manitoba, is reported. Measurements of changes in biomass and assimilation of14CO2in random and non-random samples throughout the growing season of 1973 were used. Changes in biomass ofP. Richardsonii, M. alterniflorum, M. Beckii, andC. vulgarisdetermined from random samples compared favourably with those determined from non-random samples. This was not the case forP. pectinatusbecause of its restricted occurrence. Similarly, measurements of14CO2assimilation in random samples ofP. Richardsonii, M. alterniflorum, andM. Beckiicompared well with non-random samples. Productivity values derived from14CO2uptake were far in excess of those attained from biomass changes. Seasonal trends of production and the depth distribution of production are discussed, and macrophyte production is compared with phytoplankton production.