Premium
DYNAMICS OF A PHYTOPLANKTON COMMUNITY IN AN ICE‐COVERED LAKE1
Author(s) -
Wright Richard T.
Publication year - 1964
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1964.9.2.0163
Subject(s) - water column , phytoplankton , snow , algae , environmental science , autotroph , diatom , heterotroph , oceanography , marine snow , ecology , biology , environmental chemistry , atmospheric sciences , chemistry , geology , nutrient , geography , meteorology , genetics , bacteria
Changes in the species populations and plant pigment content of a community of phytoplankton in an ice‐covered lake in eastern Massachusetts were followed closely for three months. During a snow‐free period in January and February, a number of species of flagellated algae showed exponential increase to a maximum standing crop estimated at 31 mg C/100 cm 2 . The various species occupied characteristic levels in the water column, indicating a species‐specific preference of light quantity, quality, or both. The layers of the water column receiving 0.5–20% of incident radiation accounted for over 95% of the phytoplankton. A snowfall caused a mass movement of most species to the uppermost 50 cm, a region previously avoided because of excess light. C 14 measurements indicated adaptation to low light intensities and demonstrated graphically the effect of a snow cover. The community declined rapidly following a series of snowfalls which left 29 cm of snow on the ice and allowed only 0.2% of incident light to penetrate to the water column. Laboratory experiments revealed that two species of cryptomonads isolated from the lake are capable of growing at low temperatures in the dark on acetate but not on glucose and were also able to supplement heterotrophic growth with autotrophic growth in light of as low as 65 lux intensity.