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A detailed organic carbon budget as an ecosystem‐level calibration of bacterial respiration in an oligotrophic lake during midsummer
Author(s) -
Cole Jonathan J.,
Caraco Nina F.,
Strayer David L.,
Ochs Clifford,
Nolan Scott
Publication year - 1989
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.1989.34.2.0286
Subject(s) - respiration , thymidine , bacterial growth , ecosystem , chemistry , environmental science , environmental chemistry , atmospheric sciences , biology , ecology , bacteria , botany , biochemistry , physics , dna , genetics
During a 1‐month period at the peak of summer stratification, we made intensive measurements of the major inputs and outputs of organic carbon to and from the epilimnetic water column of oligotrophic Mirror Lake, New Hampshire. These measurements included allochthonous and autochthonous components, as well as changes in storage, and were designed to construct a complete carbon budget. Bacterial respiration was compared directly to our budget in an effort to use ecosystem‐level constraints to test the major assumptions used to estimate bacterial production and respiration. On the basis of the difference between all other inputs and outputs, bacterial respiration must lie between 0.4 and 6 nmol C m −2 d −1 . With measured rates of thymidine incorporation and measured bacterial cell sizes, this organic‐C budget constrains the thymidine conversion factor (cell nM −1 thymidine) to be between 1 and 6 × 10 9 cells nM −1 thymidine for growth yields between 10 and 80%. If the thymidine conversion factor were > 10 × 10 9 cells nmol −1 , bacterial respiration alone would exceed the total input of C to the system, even at assumed growth yields of 80%. The same analysis indicates that the carbon conversion factor cannot exceed 3 × 10 −7 µ g µ m −3 for any reasonable values of growth yield and thymidine conversion factor. On the basis of our best estimates for all parameters, bacterial production was equal to 16% of primary production and bacterial respiration was about 40% as large as the respiration of macrozooplankton. The respiration of nanoflagellate microzooplankton was <10% as large as the respiration of macrozooplankton and could account for the remineralization of only 25 % of bacterial production.