Non‐Redfield carbon and nitrogen cycling in the Arctic: Effects of ecosystem structure and dynamics
Kendra L. Daly
Douglas W. R. Wallace
Walker O. Smith
Annelie Skoog
Rubén Lara
Michel Gosselin
Eva Falck
Patricia L. Yager
Abstract
The C:N ratio is a critical parameter used in both global ocean carbon models and field studies to understand carbon and nutrient cycling as well as to estimate exported carbon from the euphotic zone. The so-called Redfield ratio (C:N = 6.6 by atoms) [Redfield et al., 1963] is widely used for such calculations. Here we present data from the NE Greenland continental shelf that show that most of the C:N ratios for particulate (autotrophic and heterotrophic) and dissolved pools and rates of transformation among them exceed Redfield proportions from June to August, owing to species composition, size, and biological interactions. The ecosystem components that likely comprised sinking particles and had relatively high C:N ratios (geometric means) included (1) the particulate organic matter (C:N = 8.9) dominated by nutrient-deficient diatoms, resulting from low initial nitrate concentrations (approximately 4 μM) in Arctic surface waters; (2) the dominant zooplankton, herbivorous copepods (C:N = 9.6), having lipid storage typical of Arctic copepods; and (3) copepod fecal pellets (C:N = 33.2). Relatively high dissolved organic carbon concentrations (median 105 μM) were approximately 25 to 45 μM higher than reported for other systems and may be broadly characteristic of Arctic waters. A carbon-rich dissolved organic carbon pool also was generated during summer. Since the magnitude of carbon and nitrogen uncoupling in the surface mixed layer appeared to be greater than in other regions and occurred throughout the productive season, the C:N ratio of particulate organic matter may be a better conversion factor than the Redfield ratio to estimate carbon export for broad application in northern high-latitude systems.
Daly K.L., Wallace D.W.R., Smith W.O., Skoog A., Lara R., Gosselin M., Falck E. and Yager P.L. (1999) Non‐Redfield carbon and nitrogen cycling in the Arctic: Effects of ecosystem structure and dynamics. Journal of Geophysical Research Atmospheres 104(C2): 3185-3199. 10.1029/1998JC900071
@article{Daly1999,
Title = {Non‐Redfield carbon and nitrogen cycling in the Arctic: Effects of ecosystem structure and dynamics},
Author = {Daly, Kendra L. and Wallace, Douglas W. R. and Smith, Walker O. and Skoog, Annelie and Lara, Rubén and Gosselin, Michel and Falck, Eva and Yager, Patricia L.},
Editor = {},
Journal = {Journal of Geophysical Research Atmospheres},
Year = {1999},
Pages = {3185-3199},
Volume = {104},
Doi = {10.1029/1998JC900071},
Abstract = {The C:N ratio is a critical parameter used in both global ocean carbon models and field studies to understand carbon and nutrient cycling as well as to estimate exported carbon from the euphotic zone. The so-called Redfield ratio (C:N = 6.6 by atoms) [Redfield et al., 1963] is widely used for such calculations. Here we present data from the NE Greenland continental shelf that show that most of the C:N ratios for particulate (autotrophic and heterotrophic) and dissolved pools and rates of transformation among them exceed Redfield proportions from June to August, owing to species composition, size, and biological interactions. The ecosystem components that likely comprised sinking particles and had relatively high C:N ratios (geometric means) included (1) the particulate organic matter (C:N = 8.9) dominated by nutrient-deficient diatoms, resulting from low initial nitrate concentrations (approximately 4 μM) in Arctic surface waters; (2) the dominant zooplankton, herbivorous copepods (C:N = 9.6), having lipid storage typical of Arctic copepods; and (3) copepod fecal pellets (C:N = 33.2). Relatively high dissolved organic carbon concentrations (median 105 μM) were approximately 25 to 45 μM higher than reported for other systems and may be broadly characteristic of Arctic waters. A carbon-rich dissolved organic carbon pool also was generated during summer. Since the magnitude of carbon and nitrogen uncoupling in the surface mixed layer appeared to be greater than in other regions and occurred throughout the productive season, the C:N ratio of particulate organic matter may be a better conversion factor than the Redfield ratio to estimate carbon export for broad application in northern high-latitude systems.},
}
TY - JOUR
AU - Daly, Kendra L.
AU - Wallace, Douglas W. R.
AU - Smith, Walker O.
AU - Skoog, Annelie
AU - Lara, Rubén
AU - Gosselin, Michel
AU - Falck, Eva
AU - Yager, Patricia L.
TI - Non‐Redfield carbon and nitrogen cycling in the Arctic: Effects of ecosystem structure and dynamics
T2 - Journal of Geophysical Research Atmospheres
PY - 1999
SP - 3185-3199
VL - 104
DO - 10.1029/1998JC900071
AB - The C:N ratio is a critical parameter used in both global ocean carbon models and field studies to understand carbon and nutrient cycling as well as to estimate exported carbon from the euphotic zone. The so-called Redfield ratio (C:N = 6.6 by atoms) [Redfield et al., 1963] is widely used for such calculations. Here we present data from the NE Greenland continental shelf that show that most of the C:N ratios for particulate (autotrophic and heterotrophic) and dissolved pools and rates of transformation among them exceed Redfield proportions from June to August, owing to species composition, size, and biological interactions. The ecosystem components that likely comprised sinking particles and had relatively high C:N ratios (geometric means) included (1) the particulate organic matter (C:N = 8.9) dominated by nutrient-deficient diatoms, resulting from low initial nitrate concentrations (approximately 4 μM) in Arctic surface waters; (2) the dominant zooplankton, herbivorous copepods (C:N = 9.6), having lipid storage typical of Arctic copepods; and (3) copepod fecal pellets (C:N = 33.2). Relatively high dissolved organic carbon concentrations (median 105 μM) were approximately 25 to 45 μM higher than reported for other systems and may be broadly characteristic of Arctic waters. A carbon-rich dissolved organic carbon pool also was generated during summer. Since the magnitude of carbon and nitrogen uncoupling in the surface mixed layer appeared to be greater than in other regions and occurred throughout the productive season, the C:N ratio of particulate organic matter may be a better conversion factor than the Redfield ratio to estimate carbon export for broad application in northern high-latitude systems.
ER -
Details
Datum15.02.1999
JournalJournal of Geophysical Research Atmospheres