植物プランクトンの光合成と物質生産に関する生態学的研究 III

Abstract

1) Assuming the homogeneous vertical distribution of phytoplankton in water, the relationship between chlorophyll concentration in water and depth of euphotic zone was deduced, and the chlorophyll amount in the euphotic zone was estimated for the water with various concentration of chlorophyll. The highest chlorophyll amount was about 900mg/m2 in the range of chlorophyll concentration above 5mg/l. Below this concentration of chlorophyll, chlorophyll amount in euphotic zone decreased with decrease in chlorophyll concentration in water.2) By using photosynthesis-light curves of Scenedesmus sp. and light data, the gross and net primary productivity under most favorable and idealized simple conditions was calculated for the water with various chlorophyll concentration. At 20°, the maximum gross primary productivity of about 24gC/m2/day was obtained above a chlorophyll concentration of 5mg/l and the maximum net primary productivity of about 19.5gC/m2/day was obtained above a chlorophyll concentration of 1mg/l. Below these chlorophyll concentrations, both the gross and net primary productivity under unit water surface decreased with decrease in the chlorophyll concentration.