| Title |
Determination of Primary Productivity of Phytoplankton in Kyeongan Stream with Photosynthesis-Irradiance Curve |
| Authors |
한명수(Myung Soo Han),이동석(Dong Seok Yi),박갑성(Kap Song Park) |
| Abstract |
Chlorophyll a standing crops of phytoplankton, photosynthesis-irradiance curve (P-I curve). primary productivity, and physico-chemical environmental factors were measured at Kwangdong bridge of Kyeongan Stream from April 3 to November 21 in 1997. The studied area was characterized as a stream-lake system where the physico-chemical environmental factors had abruptly fluctuated depending on precipitation. Variations in environmental factors except for water temperature showed little seasonal trend. Kyeongan Stream was a strongly eutrophicated, often showing high concentration of nutrient and chl-a. Standing crops of phytoplankton ranged from 628-144,500 cells/ml. The highest values of standing crops were 10^5 cells/㎖ when Cyanophyceae, Microcystis sp. and Aphanizomenon flos-aquae were bursting in the fall. Daily productivity was changed from 384 to 3.713 ㎎ C/㎡/d, which were almost similar to that of Nakdong River which was well known as a eutrophicated area. The monthly readings of P-I curve were divided into four types based on the values of P-max (maximum photosynthesis rate) and a (photoadaptive rate). These four types of P-I curve were a reflective of a change of dominant species, which were effected by seasonal variations of environmental factors such as irradiance. water temperature, nutrients and hydrodynamics. High primary productivity of dominant species such as Stephanodiscus sp., Cryptomonas erosa. Micractinium pursillum var. elegans and Aphanizomenon flos-aquae was maintained seasonally in Kyeongan Stream. |