scholarly journals Dissolved and Particulate Organic Carbon in Icelandic Proglacial Streams: A First Estimate

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 748 ◽  
Author(s):  
Peter Chifflard ◽  
Christina Fasching ◽  
Martin Reiss ◽  
Lukas Ditzel ◽  
Kyle S. Boodoo
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Ice Cap ◽  
Glacier Terminus ◽  
Fluorescence Measurements ◽  
Sampling Locations ◽  
Carbon Release ◽  
Annual Carbon ◽  
Spatio Temporal

Here for the first time, we analyze the concentration of dissolved (DOC) and particulate organic carbon (POC), as well as its optical properties (absorbance and fluorescence) from several proglacial streams across Iceland, the location of Europe’s largest non-polar ice cap. We found high spatial variability of DOC concentrations and dissolved organic matter (DOM) composition during peak melt, sampling 13 proglacial streams draining the 5 main Icelandic glaciers. Although glacial-derived organic matter (OM) was dominated by proteinaceous florescence, organic matter composition was variable among glaciers, often exhibiting relatively higher aromatic content and increased humification (based on absorbance and fluorescence measurements) closer to the glacier terminus, modulated by the presence of glacial lakes. Additional sampling locations the in flow path of the river Hvitá revealed that while POC concentrations decreased downstream, DOC concentrations and the autochthonous fraction of OM increased, suggesting the reworking of the organic carbon by microbial communities, with likely implications for downstream ecosystems as glaciers continue to melt. Based on our measured DOC concentrations ranging from 0.11 mg·L−1 to 0.94 mg·L−1, we estimate a potential annual carbon release of 0.008 ± 0.002 Tg·C·yr−1 from Icelandic glaciers. This non-conservative first estimate serves to highlight the potentially significant contribution of Icelandic pro-glacial streams to the global carbon cycle and the need for the quantification and determination of the spatio-temporal variation of DOC and POC fluxes and their respective drivers, particularly in light of increased rates of melting due to recent trends in climatic warming.

scholarly journals Dissolved and particulate organic carbon in Icelandic proglacial streams

2018 ◽  
Author(s):  
Peter Chifflard ◽  
Christina Fasching ◽  
Martin Reiss ◽  
Lukas Ditzel
Keyword(s):  
Organic Matter ◽  
Optical Properties ◽  
Organic Carbon ◽  
Microbial Communities ◽  
Particulate Organic Carbon ◽  
Ice Cap ◽  
Glacier Terminus ◽  
Aromatic Content ◽  
Doc Concentration ◽  
First Time

Abstract. Here for the first time, we analyze the concentration of dissolved (DOC) and particulate organic carbon (POC), as well as its optical properties (absorbance and fluorescence) in proglacial streams of Iceland, location of Europe's largest nonpolar ice cap. DOC and POC concentrations range from 0.11 mg L−1 to 0.94 mg L−1 and from 0.67 mg L−1 to 173.33 mg L−1, respectively. We estimate an annual release of 0.008 Tg C yr−1 (DOC) and 1.72 Tg C yr−1 (POC) from Icelandic glaciers. Compared to the global release of 1.97 Tg C yr−1 POC, these first calculations underline the necessity to include the Icelandic glaciers in global organic carbon budgets. Based on optical properties, we found that although glacial derived organic matter (OM) was dominated by proteinaceous florescence, organic matter composition was variable among glaciers, often exhibiting relatively higher aromatic content and increased humification closer to the glacier terminus, modulated by the presence of glacial lakes. While POC concentration decreased downstream, DOC concentration as well as the autochthonous fraction of OM increased suggesting the reworking of the OC by microbial communities, which has implications for downstream ecosystems as glaciers continue to melt.

Spatio-temporal variability of natural organic matter in Lancang River: concentration, sources and destination

2020 ◽  
Author(s):  
Ting Wang
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Natural Organic Matter ◽  
Temporal Variability ◽  
Anthropogenic Activities ◽  
Sharp Decrease ◽  
C3 Plants ◽  
Lancang River ◽  
Spatio Temporal ◽  
The Impact

<p>Natural organic matter (NOM) played an important role in the riverine and global carbon cycle. In order to evaluate the impact of river discharge and anthropogenic activities on the spatio-temporal variability of NOM content and sources in Lancang River, China, a comprehensive study was conducted in two years from the head to the leave-boundary section. As results, the DOC value ranged among 0.91-2.80 mg/L, with sharp decrease in the middle reaches and downstream. While the SOC value significantly enhanced along the water flow, varied from 0.06% to 3.54%. The isotopic composition of organic carbon (δ13C) suggested that predominant contribution of NOM is C3 plants in the upper reach, algae and soil organic matter in the middle reach, and aquatic plants in the downstream. EEM-PARAFAC results proved that NOM in Lancang River is mainly terrestrial organic carbon, while in situ microbial transformed NOM is very low. Moreover, the sharp increase of dissolved CO2 concentration in the lower reaches confirmed the strong respiration of microorganisms due to the higher DO and water temperature, thus resulted in the significantly different fluctuations of DOC and SOC.</p>

Rates of carbon fixation, organic carbon release and translocation in a reef-building foraminifer, Marginopora vertebralis

1977 ◽  
Vol 28 (3) ◽  
pp. 311 ◽  
Author(s):  
DF Smith ◽  
WJ Wiebe
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Particulate Organic Carbon ◽  
Carbon Fixation ◽  
Turnover Time ◽  
In Situ Incubation ◽  
Carbon Release ◽  
Hermatypic Corals ◽  
Shell Carbonate

Rate measurements obtained in this study and the population densities of foraminifera reported elsewhere suggest that such organisms may well exceed the hermatypic corals in their contribution to reef biogensis and energy fluxes. The average rates at which M. vertebralis photosynthetically fixes carbon into particulate organic carbon, dissolved organic carbon, and shell carbonate, per square centimetre of organism, were estimated to be 50, 1 .5, and 26 ng C min-1 respectively. Exogenously supplied dissolved organic carbon was taken up by M. vertebralis at a rate of 0.05 ng C min-1 in the light, and 0.09 ng C min-1 in the dark per square centimetre of organism. The turnover time of particulate organic carbon (91 h) was measured in a long-term in situ incubation during which 19% of the radioactivity lost from the particulate organic carbon entered the calcareous foraminiferal shell.

Proteins: Amino Acids and Amines

2011 ◽  
Author(s):  
Thomas S. Bianchi ◽  
Elizabeth A. Canuel
Keyword(s):  
Amino Acids ◽  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Particulate Organic Carbon ◽  
Nitrogen Cycle ◽  
Organic Nitrogen ◽  
Building Blocks ◽  
Marine Organisms ◽  
Carbon And Nitrogen

This chapter discusses proteins, which make up approximately 50% of organic matter and contain about 85% of the organic nitrogen in marine organisms. Peptides and proteins comprise an important fraction of the particulate organic carbon (13–37%) and particulate organic nitrogen (30–81%), as well as dissolved organic nitrogen (5–20%) and dissolved organic carbon (3–4%) in oceanic and coastal waters. In sediments, proteins account for approximately 7 to 25% of organic carbon and an estimated 30 to 90% of total nitrogen. Amino acids are the basic building blocks of proteins. This class of compounds is essential to all organisms and represents one of the most important components in the organic nitrogen cycle. Amino acids represent one of the most labile pools of organic carbon and nitrogen.

scholarly journals Organic matter sources, fluxes and greenhouse gas exchange in the Oubangui River (Congo River basin)

2012 ◽  
Vol 9 (6) ◽  
pp. 2045-2062 ◽  
Author(s):  
S. Bouillon ◽  
A. Yambélé ◽  
R. G. M. Spencer ◽  
D. P. Gillikin ◽  
P. J. Hernes ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Seasonal Variations ◽  
Dissolved Inorganic Carbon ◽  
Low Flow ◽  
Tropical Rivers ◽  
Particulate Nitrogen ◽  
Congo River

Abstract. The Oubangui is a major tributary of the Congo River, draining an area of ~500 000 km2 mainly consisting of wooded savannahs. Here, we report results of a one year long, 2-weekly sampling campaign in Bangui (Central African Republic) since March 2010 for a suite of physico-chemical and biogeochemical characteristics, including total suspended matter (TSM), bulk concentration and stable isotope composition of particulate organic carbon (POC and δ13CPOC), particulate nitrogen (PN and δ15NPN), dissolved organic carbon (DOC and δ13CDOC), dissolved inorganic carbon (DIC and δ13CDIC), dissolved greenhouse gases (CO2, CH4 and N2O), and dissolved lignin composition. δ13C signatures of both POC and DOC showed strong seasonal variations (−30.6 to −25.8‰, and −31.8 to −27.1‰, respectively), but their different timing indicates that the origins of POC and DOC may vary strongly over the hydrograph and are largely uncoupled, differing up to 6‰ in δ13C signatures. Dissolved lignin characteristics (carbon-normalised yields, cinnamyl:vanillyl phenol ratios, and vanillic acid to vanillin ratios) showed marked differences between high and low discharge conditions, consistent with major seasonal variations in the sources of dissolved organic matter. We observed a strong seasonality in pCO2, ranging between 470 ± 203 ppm for Q < 1000 m3 s−1 (n=10) to a maximum of 3750 ppm during the first stage of the rising discharge. The low POC/PN ratios, high %POC and low and variable δ13CPOC signatures during low flow conditions suggest that the majority of the POC pool during this period consists of in situ produced phytoplankton, consistent with concurrent pCO2 (partial pressure of CO2) values only slightly above and, occasionally, below atmospheric equilibrium. Water-atmosphere CO2 fluxes estimated using two independent approaches averaged 105 and 204 g C m−2 yr−1, i.e. more than an order of magnitude lower than current estimates for large tropical rivers globally. Although tropical rivers are often assumed to show much higher CO2 effluxes compared to temperate systems, we show that in situ production may be high enough to dominate the particulate organic carbon pool, and lower pCO2 values to near equilibrium values during low discharge conditions. The total annual flux of TSM, POC, PN, DOC and DIC are 2.33 Tg yr−1, 0.14 Tg C yr−1, 0.014 Tg N yr−1, 0.70 Tg C yr−1, and 0.49 Tg C yr−1, respectively. While our TSM and POC fluxes are similar to previous estimates for the Oubangui, DOC fluxes were ~30% higher and bicarbonate fluxes were ~35% lower than previous reports. DIC represented 58% of the total annual C flux, and under the assumptions that carbonate weathering represents 25% of the DIC flux and that CO2 from respiration drives chemical weathering, this flux is equivalent to ~50% of terrestrial-derived riverine C transport.

Seasonal Transport Characteristics of Suspended Particulate Organic Carbon in the Middle and Lower Yangtze River and the Relationship with Three Georges Reservoir

2013 ◽  
Vol 663 ◽  
pp. 1058-1063 ◽  
Author(s):  
Xiao Li Liu ◽  
Shou Ye Yang ◽  
Wen Rui Huang ◽  
Lin Lu Li ◽  
Chen Zeng ◽  
...  
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Particulate Matter ◽  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Suspended Matter ◽  
Yangtze River ◽  
Three Gorges ◽  
The Three Gorges ◽  
Suspended Particulate

The suspended matter samples collected about 2 times every month in Datong of Yangtze River from May to November 2010 were used for determination of grain size and particulate organic carbon (POC) component. The results indicated that the size composition and organic carbon concentrations of Datong showed obvious seasonal characteristics. The median grain size of the suspended particulate matter ranged from 5.8 to 7.8Φ, decreased in summer (July to September) and increased in autumn (October to November). The POC% of the suspended particulate matter ranged from 0.87% to 1.18%, and was lower in summer, because high sediment discharge had dilution effect for organic carbon. The increase of the turbidity of water reduced the production capacity, and the organic matter correspondingly decreased. POC% decreased with the reduction of median grain size, which suggested that organic matter into the river in summer is mainly organic debris, but not mainly absorbed by the fine particles of clay. CaCO3 content ranged 3.7% to 7.6% and was higher in summer, which reflected the increased source contribution of the upper stream. It decreased in autumn, which reflected the increased source contribution of the middle and lower stream. Since the impoundment of the Three Gorges Reservoir, POC% in Datong were significantly higher than before, which showed the rise of fine particulate matter component and its stronger adsorption of organic matter. The Three Gorges Dam had significant influence on the grain size and organic composition of suspended matter of theYangtze River into the sea. Its potential environmental impact of bio-geochemical effects deserves more research attention.

scholarly journals Spatiotemporal Characterization of Chromophoric Dissolved Organic Matter (CDOM) and CDOM-DOC Relationships for Highly-Polluted River

2016 ◽  
Author(s):  
Sijia Li ◽  
Jiquan Zhang ◽  
Guangyi Mu ◽  
Hanyu Ju ◽  
Rui Wang ◽  
...  
Keyword(s):  
Water Quality ◽  
Molecular Weight ◽  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Matter ◽  
Ternary Phase Diagram ◽  
Spectral Characteristics ◽  
River Watershed ◽  
Sampling Locations ◽  
Polluted Waters

Spectral characteristics of CDOM in water column are a key parameter for bio-optical modeling. Knowledge of CDOM optical properties and spatial discrepancy based on the relationship between water quality and spectral parameters in Yinma River watershed with in situ data collected highly-polluted waters are exhibited in this study. Seasonal field data sets collected over a period of 2 months in 2015 in Yinma River Watershed. Based on the comprehensive index method, the riverine waters showed serious contamination, especially the COD, Fe, Mn, Hg and DO were out of range contamination warning. Dissolved organic carbon (DOC) and total suspended matter (TSM) with prominent non-homogenizing were significantly high in the riverine waters, but chlorophyll-a (Chl-a) was opposite. Ternary phase diagram showed that non-algal paritcles absorption played an important role in total non-water light absorption (&gt;50%) in most sampling locations, and mean contribution of CDOM were 13% and 22% in summer and autumn respectively. Analysis of ratio of absorption at 250-365 nm (E250:365) and spectral slope (S275-295) indicated that CDOM had higher aromaticity and molecular weight in autumn than in summer, is consistent with the results of water quality and relative contribution. Redundancy analysis (RDA) indicated that the environmental variables OSM had a strong correlation with CDOM absorption, followed by heavy metal, e.g., Mn, Hg and Cr6+. However, for the specific UV absorbance (SUVA254), the seasonal values showed opposite results compared with the reported literature. The potential reasons were the more UDOM (uncolored Dissolved Organic Matter) from human source (wastewater effluent) existed in waters. Terrigenous inputs simultaneously are in relation to the aCDOM(440)-DOC relationship with the correlation coefficient was 0.90 in summer (2-tailed, p&lt;0.01), and 0.58 in autumn (2-tailed, p&lt;0.05). Spatial distribution of CDOM parameters exhibited that the downstream regions focused on dry land have high CDOM molecular weight and aromatic hydrocarbon. Partial sampling locations around the cities or countries generally showed abnormal values due to terrigenous inputs. As a bio-optical model parameter, spectral characteristic of CDOM is helpful in adjusting the derived algorithms in highly-polluted environments. The study on organic carbon and pollutants in highly-polluted waters had an important contribution to global carbon balance estimation and water environment protection.

scholarly journals TOTAL AND PARTICULATE CONTENTS AND VERTICAL STRATIFICATION OF ORGANIC CARBON IN AGROFORESTRY SYSTEM IN CAATINGA

2021 ◽  
Vol 34 (2) ◽  
pp. 443-451
Author(s):  
BRUNA DE FREITAS IWATA ◽  
MARIA LETÍCIA STEFANY MONTEIRO BRANDÃO ◽  
REGIS DOS SANTOS BRAZ ◽  
LUIZ FERNANDO CARVALHO LEITE ◽  
MIRIAN CRISTINA GOMES COSTA
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Organic Matter Content ◽  
Gliricidia Sepium ◽  
Agroforestry System ◽  
Matter Content ◽  
Vertical Stratification ◽  
Sensitivity Index ◽  
Organic Residues

ABSTRACT The objective of this work was to evaluate the variation in total and particulate organic carbon contents, carbon vertical stratification, and sensitivity index of organic matter fractions in soils with organic residues arranged in alleys in an agroforestry system, with and without use of fire, in the Caatinga biome, in Brazil. The experiment was conducted in a split-plot arrangement with four replications, with the factor fire in the plots, and the factor organic residues in the subplots. The organic residues used consisted of Gliricidia sepium plants; G. sepium plants and carnauba processing residue; G. sepium plants and bio-compost; and G. sepium plants, carnauba processing residue, and bio-compost, which were evaluated in three soil layers. The alleys with carnauba processing residue, G. sepium plants, and bio-compost presented a better maintenance of particulate, and mineral-associated organic carbon contents. Thus, the agroforestry management in alleys using these three residues was efficient for the maintenance of labile and recalcitrant organic matter compartments. Particulate organic carbon was more sensitive to changes in soil management than total organic matter content, in all alleys, presenting higher sensitivity indexes.

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