Open AccessThe importance of bacterial utilization of released phytoplankton photosynthate in two humic forest lakes in southern Finland
Author(s) -
Jones Roger I.,
Salonen Kalevi
Publication year - 1985
Publication title -
ecography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.973
H-Index - 128
eISSN - 1600-0587
pISSN - 0906-7590
DOI - 10.1111/j.1600-0587.1985.tb01163.x
Subject(s) - phytoplankton , photosynthesis , dissolved organic carbon , ecology , carbon fixation , environmental chemistry , botany , environmental science , biology , chemistry , nutrient
Bacterial utilization of photosynthetically fixed dissolved organic carbon (PDOC) released from natural phytoplankton assemblages was studied in two small, extremely humic, forest lakes in southern Finland. Bacterial activity (measured as uptake of 14 C‐glucose) and phytoplankton photosynthesis (measured as light uptake of 14 CO 2 ) could be most effectively separated using Nuclepore filters of pore size 1–2 μm. Released PDOC was 10–67% of total phytoplankton carbon fixation during in situ experiments, and represented about 0.1% of total DOC. Net uptake of PDOC by bacteria was found to be about 20% during 24 hour laboratory incubations, although about 40% of PDOC present at the start of an experiment could be utilized by bacteria during a 24 hour period. PDOC does not provide a quantitatively important substrate supply for bacterial respiration in humic forest lakes.