New observations and perspectives from organic geochemistry - PDF document

is not in living Rice, 1980). researchers proposed that the nitrogen enrichment non-living material e. in matrix, not Lee (1980) hypothesized that microbes might contribute nitrogen increase, this contribution is plant-derived detritus (may reducing carbohydrates carbohydrates and Bostock, 1958; a significant detrital nitro- as protein-carbohydrate 1979; Rice, in modem ancient sediments (Degens Reuter, 1962; complement recent detritus derived a variety have attempted to relate macrophyte detritus to detrital protein, reactive phenolic, alkali-soluble, polycondensed organic) contents. detritus selected this study a variety sources (2 macroalgae, marsh grass, nitrogen. Drawing on propose a nitrogen accumulation further study detritus nitrogen (C. Agardh) turtle grass Spartina alterniflora red mangrove Linnaeus were lyophilized were placed mouth 6.2 brim capac- and submerged tank receiv- detritus types the absence 50, 100, the residual detritus was carbon, nitrogen, protein, carbohydrate, reactive phenol, and as described below. the experimental equipment have Carbon, Nitrogen Percent carbon detritus samples each detritus-age combination) using kin-Elmer Model detritus samples untreated samples indicated that carbonate-carbon carbon contents percent ash-free Preteatment for Biochemical Assays protein, reactive reactive phenol, humic content, were extracted interfering lipids vacuum filtration were added in the away residual extracted detritus excess solvent was drawn The extracted detritus was were less a laboratory analyses described dilute alkaline et al. based on the ability amino acids tryptophan Ecol. Prog. 153-162, 1982 protein during decomposi- each detritus, protein r (Gracilaria foliifera) final (t reactive carbohydrate, reactive material in 3. Final carbohydrate contents significantly different CHANGE IN NITROGEN CONTENT 5. Linear stance and nitrogen content of decomposition. substance and gen (ash-free are calculated in the slope and intercept the regression material to to 1501 - % Humics [t=O]) decreased somewhat differently: S. schroederi (+2.42%) �R. mangle(f0.90) � G. foliifera (+0.33%) � S, alterniflora (-0.25%) � T. testudinum (0.51%). The change in humic content of the detritus between D 0 and D 150 was positively and significantly related to the change in % N (Fig. 5). Estimates of the uncer- tainties in the slope and intercept of the least-squares regression line (Bevington, 1969) of Fig. 5 indicate that the line is not significantly different from the straight line of unit slope rials. Correlation demonstrated that nitrogen enrichment macrophyte detritus synonymous with protein enrichment plant mate- rial, nitrogen enrichment arises because microbial biomass cannot account increase, nitrogen sequestered in the Odum et Rice, 1980; references cited reactive carbohydrates phenols which in the matrix (discussed below) that there substantial build-up synthesized humic is strong positive correlation humic material in macrophyte detritus. this strong the central below), and (3) the nitrogen problem that mature humic substances lacustrine sediments in organic detrital nitrogen enrichment nitrogenous humic substances detritus-microbe complex. the perspective organic geochemistry, the beginning humification process. organic nitrogen monomeric precursors to form substances (kerogens, humic acids weights usually much greater have higher substances (e. g. acids) (Schnitzer, detritus contained (ash-free basis) humic acid acid extracts contained Laminaria digitata detritus contained humic acids contained marine sediment samples, found that components was significantly fractions. Analogous results humus (Durbach nitrogen extracted amino acid nitrogen was non-amino humic nitrogen; alkaline-insoluble residue, amino acid nitrogen and at non-amino humic nitrogen rochova, 1972). becomes structurally nitrogen becomes incorporated into progressively heterocyclic configurations, increase substantially although microbial assimilation decreases (Flaig, mangrove detritus reactive phenols carbohydrates, indicating increased capacity bind proteins bial exudates) fact, microbial these reactive plant decomposition products Feeney, 1970). Consequently, proteinaceous matter can easily provide the nitrogen which accumulates humifying detritus matrix. Because is gradually correlate well as aging proceeds. Con- nitrogen increase living microbial mass the degree humification (Fig. humic nitrogen during in assessing detritus. However, decomposed that the case may still noted that than sedimentary similar molecular weight because the condensed, aromatic character nitrogen only after in a non-humic marsh grass detritus has aged several months version factor dilute alkali 1959) may living plant material; however, this tech- be confidently used to assess because dilute alkaline hydrolysis also extracts nitrogen-rich humic acids. Treatment acid extrac- also removes hydrolysable amino-sugar amino-phenol condensation products. Applications detritus derived salt marsh plants (Haines Odum et al., overestimate 'protein enrichment'. Some gen in protein molecules could persist temporarily sedimentary humic relic 'polypeptide' regions romolecular structure (Kemp technique developed show that detritus nitrogen problem related substances. Anal. Durbach, P., (1963). The chemistry Soils Fertil. (1970). Seasonal a cause the tannin W., Cefalu, S. (1975). Microbial activities the mangrove Proc. Int. Fenchel, T. (1972). Aspects chains in marine benthos. stances: aspects chemical properties, In: Povoldeo, (eds.) Humic Wageningen, pp. and Juncus Biol. Ecol. 40: phenolic compounds, Press, New amphipods on azteca (Amphipoda). T. (1976). The central decomposition. In: isms in decomposition processes. H. (1975). Detritus formation eelgrasss (Zostera marina the relative leaching, and Microbial production lular material: importance benthic ecology. C. (eds.) Marine benthic dynamics. Univ, ition in the terrestrial nitrogen Golterman, H. (eds.) Humic substances. gen, pp. W., Mudrochova, A. (1972). Nitrogen in sedimented organic Humic substances. Agricultural Publishing King, H. chemical analysis and the between disappearance synthetic phenolic mers incorporating amino derivatives. phenol rea- the nutrition prosobranch Hydrobia ulvae the bivalve (in press). alterniflora. Estuaries E., Kirk, (1979). Non-protein nitrogen compounds associated with particles detritus. Oikos Phenolic compounds phycological methods. humic acids associated with marine sedi- compounds isolated some decomposed Fish. Res. Trace element detritus derived coastal macrophytes. tation. Georgia Institute Technology, Atlanta (1981). Dynamics detritus. Mar. Carolina salt marsh: Carolina Sea (1970). Aquatic productivity, substances. Centre Agricultural Publishing Wageningen, pp. University Park A. (1969). Studies on algal substances (humic material) Biol. Ecol. A practical analysis. Fisheries Research Godshalk, G. leaves during a woodland caloric content deposit-feeding polychaete, Sci. 12: 153-162, 1982 was submitted