Comparative geochemistries of lignins and carbohydrates in an anoxic fjord

Journal Article · Fri Jan 01 04:00:00 EST 1988 · Geochim. Cosmochim. Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(88)90062-2· OSTI ID:6996754

Hamilton, S E; Hedges, J I

A reducing, varved sediment core and monthly (May-September) plankton and sediment trap samples from Saanich Inlet, B.C., Canada, were analyzed for their elemental, lignin and neutral sugar compositions. Total yields of lignin-derived phenols from both the sediment trap and core samples indicated less than 15% and 30%, respectively, of chemically recognizable vascular plant remains, derived predominantly from gymnosperm wood and nonwoody angiosperm tissues. The elevated vanillyl and syringyl acid/aldehyde ratios of this material compared to fresh plant material indicated that it suffered mild aerobic decomposition prior to introduction to the Inlet. Organic carbon, total nitrogen, and total neutral sugars and lignin phenols all exhibited decreasing concentrations with depth in a region of uniform varving (upper 15 cm) in the sediment core. Neutral sugars were consistently the most reactive chemical class, accounting for roughly 15% of the total organic carbon turnover. Although lignin appeared to be degraded within the sediment core, this degradation was nonselective for different lignin types and did not lead to increased acid/aldehyde ratios as occur during aerobic lignin decomposition. Comparisons of the yields of individual neutral sugars from the sediment and sediment trap samples to those expected from the vascular plant component alone indicated that the vascular plant debris in the upper portion of the sediment core had lost a portion of its initial glucose, lyxose, and mannose. In contrast, rhamnose and fucose were produced by all samples in large excess of total yields expected for chemically intact vascular plant and plankton components and must have additional sources.

• Research Organization: Univ. of Washington, Seattle (USA)
• OSTI ID: 6996754
• Journal Information: Geochim. Cosmochim. Acta; (United States), Journal Name: Geochim. Cosmochim. Acta; (United States) Vol. 52:1; ISSN GCACA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580400* -- Geochemistry-- (-1989)
ALDEHYDES
AQUATIC ORGANISMS
BIOGEOCHEMISTRY
BRITISH COLUMBIA
CANADA
CARBOHYDRATES
CARBON
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CHEMISTRY
COMPARATIVE EVALUATIONS
DECOMPOSITION
DIAGENESIS
ELEMENTS
GEOCHEMISTRY
GLUCOSE
HEXOSES
LIGNIN
MANNOSE
MONOSACCHARIDES
NITROGEN
NONMETALS
NORTH AMERICA
ORGANIC COMPOUNDS
ORGANIC MATTER
PLANKTON
POLYSACCHARIDES
QUANTITATIVE CHEMICAL ANALYSIS
SACCHARIDES
SEDIMENTS