• Title/Summary/Keyword: origin of organic matter

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Soil properties and molecular compositions of soil organic matter in four different Arctic regions

  • Sujeong, Jeong;Sungjin, Nam;Ji Young, Jung
    • Journal of Ecology and Environment
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    • v.46 no.4
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    • pp.282-291
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    • 2022
  • Background: The Arctic permafrost stores enormous amount of carbon (C), about one third of global C stocks. However, drastically increasing temperature in the Arctic makes the stable frozen C stock vulnerable to microbial decomposition. The released carbon dioxide from permafrost can cause accelerating C feedback to the atmosphere. Soil organic matter (SOM) composition would be the basic information to project the trajectory of C under rapidly changing climate. However, not many studies on SOM characterization have been done compared to quantification of SOM stocks. Thus, the purpose of our study is to determine soil properties and molecular compositions of SOM in four different Arctic regions. We collected soils in different soil layers from 1) Cambridge Bay, Canada, 2) Council, Alaska, USA, 3) Svalbard, Norway, and 4) Zackenberg, Greenland. The basic soil properties were measured, and the molecular composition of SOM was analyzed through pyrolysis-gas chromatography/mass spectrometry (py-GC/MS). Results: The Oi layer of soil in Council, Alaska showed the lowest soil pH and the highest electrical conductivity (EC) and SOM content. All soils in each site showed increasing pH and decreasing SOC and EC values with soil depth. Since the Council site was moist acidic tundra compared to other three dry tundra sites, soil properties were distinct from the others: high SOM and EC, and low pH. Through the py-GC/MS analysis, a total of 117 pyrolysis products were detected from 32 soil samples of four different Arctic soils. The first two-axis of the PCA explained 38% of sample variation. While short- and mid-hydrocarbons were associated with mineral layers, lignins and polysaccharides were linked to organic layers of Alaska and Cambridge Bay soil. Conclusions: We conclude that the py-GC/MS results separated soil samples mainly based on the origin of SOM (plants- or microbially-derived). This molecular characteristics of SOM can play a role of controlling SOM degradation to warming. Thus, it should be further investigated how the SOM molecular characteristics have impacts on SOM dynamics through additional laboratory incubation studies and microbial decomposition measurements in the field.

Isotopic Determination of Terrestrial Food Sources for a Brackish Water Clam Corbicula japonica PRIME in an Estuarine System of Youngil Bay, Korea

  • Lee, Won-Chan;Park, Jin-Il;Choi, Woo-Jeung;Kim, Young-Seop;Lee, Pil-Yong;Kang, Chang-Keun
    • Journal of the korean society of oceanography
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    • v.35 no.1
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    • pp.56-64
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    • 2000
  • The importance of terrestrial organic matter as a food source for a brackish water clam Corbicula japonica was evaluated using stable carbon isotope ratios (${\delta}^{13}$C) in its tissues and potential food resources in an estuarine system of Youngil Bay, Korea. Suspended particulate organic matter (POM) had distinct ${\delta}^{13}$C values from riverine (-31.8 to -27.2%$_o$) to marine waters (-21.0 to -16.6%$_o$). Estuarine macroalgae had a wide ${\delta}^{13}$C range of -22.8 to -15.0%$_o$. The ${\delta}^{13}$C values of riverine POM were more negative than that of riverine phytoplankton (-26.5 to -24.2%$_o$) but similar to that of freshmarsh plant species (-29.1 to -27.5%$_o$ for Phragmites communis and -28.5 to -27.0%$_o$ for Salix gracilistyla), These ${\delta}^{13}$C values suggest that the POM transported by the Hyungsan River is predominantly of terrestrial origin rather than riverine autochthonous sources. The ${\delta}^{13}$C values of Corbicula japonica tissues (-28.7 to -27.2%$_o$) were most similar to values for riverine POM and freshmarsh plants. There was no significant difference in the isotopic composition of the clam individuals. The results indicate a predominant contribution of organic carbon derived from terrestrial and fresmarsh plant detritus to the diet of Corbicula japonica. Our results also confirm previous suggestion that terrestrial organic matter can be incorporated into estuarine food webs although its role is confined to the upper estuarine reaches.

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Pollution Status of Surface Sediment in Jinju Bay, a Spraying Shellfish Farming Area, Korea (살포식 패류양식해역인 진주만 표층 퇴적물의 오염도)

  • Lee, Garam;Hwang, Hyunjin;Kim, Jeong Bae;Hwang, Dong-Woon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.4
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    • pp.392-402
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    • 2020
  • We investigated the concentrations of acid volatile sulfide (AVS), ignition loss (IL), total organic carbon (TOC), total nitrogen (TN), and metallic elements (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn), in August 2015, to determine the spatial distribution and pollution status of organic matter and metals in the surface sediment of Jinju Bay, a spraying shellfish farming area, Korea. The concentrations of organic matter and metallic elements were significantly higher in the southern part of the bay than in the mouth and center of the bay. The C/N ratio (5.7~8.0) in the sediment represents the dominance of organic matter of oceanic origin in the surface sediment of the study area. The concentrations of AVS, TOC, and metals (As, Cd, Cr, Cu, Hg, Pb, and Zn) were much lower than the values of the sediment quality guidelines applied in Korea. Based on the results of the pollution load index (PLI) and ecological risk index (ERI), the metal concentrations in the surface sediment of Jinju Bay have a weakly negative ecological effect on benthic organisms although the sediments with high metal pollution status are distributed in the southern parts of the bay, with high dense shellfish farming areas. Thus, the surface sediments in Jinju Bay are not polluted with organic matter and are slightly polluted with metallic elements.

Studies on Elemental Carbon and Its Origin in Black Surface Layer on Stone Pagoda in Urban Environments (도심에 위치한 석탑 표면 흑색층 내의 원소탄소성분과 그 기원연구)

  • Do, Jin-Young
    • Journal of Conservation Science
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    • v.20
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    • pp.55-65
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    • 2007
  • Black surface layers collected from stone pagodas were analyzed to study the effects of carbon compounds on the blackening of stone surface layer. The total amounts of carbon was measured through elemental analyser. Organic and elemental carbon were measured by combustion ihrornatographic $CO_2$ determination after elimination of carbonates carbon with acid treatment. The elemental carbon concentration in the black surface layer measured 0.52wt.%. This value is not sufficient to explain the complete blackening of stone surface. To trace the origin of carbon in black surface layer on the stone pagoda, aerosol samples for PM 10 were collected at the near sites of the pagoda. The major components of them were soluble ions(42.8wt.%), carbon(38.4 wt.%) and crustal matter(16wt.%). From the high content(13wt.%) of elemental carbon in aerosol ran be deduced that it may be a prime origin for the elemental carbon in the black surface layer on the stone pagoda. The crustal matter in aerosol can be also a origin of silicate mineral in black surface layer and plays a important role in the darkening of black surface layer.

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Polycyclic Aromatic Hydrocarbons in the sediments of Kwangyang Bay on Korea (광양만 유역 퇴적토 중의 다환방향족탄화수소류)

  • Jeong, Heung Ho;Jeong, Ho Seung;Kim, Eun Yeong;Jo, Hwan Ik;Hwang, Ju Chan;Choe, Sang Won
    • Journal of Environmental Science International
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    • v.13 no.6
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    • pp.543-549
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    • 2004
  • Polycyclic aromatic hydrocarbons(PAHs) in sediments of Kwangyang bay on Korea, have been investigated by gas chromatography-mass spectrometery (GC/MS). The average content of total PAHs in all samples was 2,211ppb, and the range was from 36 to 22,699ppb. The higher concentrations were found in sediment sampled near Kwangyang iron processing plant, Taeindo. The resulting distributions of PAHs according to the number of aromatic ring and molecular ratios of specific aromatic compounds (phenanthrene, anthracene, fluoranthene and pyrene) have been discussed in terms of sample location, origin of the organic matter. Four, five and six rings of PAHs were mainly found near to Kwangyang iron processing plant, and three and four rings near to Yeosu chemical kombinat This result typically indicated the local characteristics, depending on the origin of PAHs.

An Application of $^{13}C$ Tracer for the Determination of Primary Productivity and Fatty Acid Production Rate in Shingu Reservoir (신구저수지의 1차 생산 및 지방산 생성속도 결정을 위한 $^{13}C$ 추적자 활용 연구)

  • Lee, Yeon-Jung;Kim, Min-Seob;Shin, Kyung-Hoon;Hwang, Soon-Jin
    • Korean Journal of Ecology and Environment
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    • v.41 no.spc
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    • pp.21-26
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    • 2008
  • The in situ incubation experiment was carried out using $^{13}C$ tracer to determine primary productivity and fatty acid production rate in the shallow, eutrophic Shingu reservoir on 4th July. Particulate organic matter (POM) accounted for 76% in suspended particulate matter (SPM), and average concentration of chlorophyll-${\alpha}$ was $89{\mu}g\;L^{-1}$ in the euphotic layer. Total amount of chlorophyll-${\alpha}$ (Chl-${alpha}$), primary productivity and Chl-${alpha}$ specific productivity in euphotic layer were 112 mg Chl-${alpha}m^{-2}$, 3.53 g C $m^{-2}\;d^{-1}$, 32mg C mg Chl-${\alpha}^{-1}\;d^{-1}$, respectively. The fatty acid composition in newly produced organic matter and suspended organic matter didn't show any significant difference, demonstrating that autochthonous organic matter should be a major source of POM pool. In addition, the fatty acids of bacterial origin were increased through extracellular release of newly photosynthesized DOC, and closely coupled with bacterial assimilation. This result suggests that organic carbon should be actively cycled through the microbial loop in Shingu reservoir in summer.

Gas ebullition associated with biological processes in radioactively contaminated reservoirs could lead to airborne radioactive contamination

  • E.A. Pryakhin;Yu.G. Mokrov;A.V. Trapeznikov;N.I. Atamanyuk;S.S. Andreyev;A.A. Peretykin;K. Yu. Mokrov;M.A. Semenov;A.V. Akleyev
    • Nuclear Engineering and Technology
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    • v.55 no.11
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    • pp.4204-4212
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    • 2023
  • Background: Storage reservoirs of radioactive waste could be the source of atmospheric pollution due to the efflux of aqueous aerosol from their water areas. The main mechanism of formation of aqueous aerosols is the collapse of gas bubbles at the water surface. In this paper, we discuss the potential influence of biological factors on gas ebullition in the water areas of the radioactively contaminated industrial reservoirs R-9 (Lake Karachay) and R-4 (Metlinsky pond) of the Mayak PA. The emission of the released non-dissolved gases captured with gas traps in reservoir R-9 was (88-290) ml/m2 per day (2015) and in reservoir R-4 (270-460) ml/m2 per day (2016). The analysis of gas composition in reservoir R-4 (60% methane, 35% nitrogen, 2.4% oxygen, 1.5% carbon dioxide) confirms their biological origin. It is associated with the processes of organic matter destruction in bottom sediments. The major source of organic matter in bottom sediments is the dying phytoplankton developing in these reservoirs. Conclusion: The obtained results form the basis to set a task to quantify the relationship between the phytoplankton development, gases ebullition and radioactive atmosphere contamination.

The Estimation of Food Sources for Macroinvertebrates as Stenopsyche marmorata in Natory Stream by Fatty Acid (지방산 분석에 의한 나토리 하천 대형 무척추동물인 Stenopsyche marmorata의 먹이원 평가)

  • Shin, Woo-Seok;Kim, Boo-Gil;Lee, Yong-Doo
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.2
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    • pp.97-102
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    • 2012
  • The purpose of this study is to clarify the origin and the variation of essential fatty acid (FA) and food sources of Stenopsyche marmorata at downstream region of Dam. As a result, the water particulate organic matter (POM) is mainly derived from diatom, green algae and bacteria. Moreover, the main food sources of S. marmorata mainly used diatom, green algae and bacteria. ${\omega}3$ essential FA of S. marmorata was higher than ${\omega}6$, and showed about 7 for essential FA ratio.

Distribution of sewage-derived organic matter using fecal sterol in Masan Bay, Korea (마산만의 하수기인 유기물 fecal sterol의 분포)

  • Choi Min-Kyu;Moon Hyo-Bang;Kim Sang-Soo;Lee Yoon
    • Journal of Environmental Science International
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    • v.14 no.5
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    • pp.481-490
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    • 2005
  • Surface sediments and seawater were sampled at Masan and Haengam Bays of Korea, to evaluate contamination by sewage-derived organic matter using fecal sterols, Six stream-water samples into Masan and Haengam Bays were also sampled. Total concentrations of eight sterols (coprostanol, epichloestanol, epicoprostanol, cholesterol, cholestanol, brassicasterol, stigmasterol and $\beta-sitosterol$) were in the range of $1,274\~4,768{\mu}g/g$ dry weight in suspended particulate from the stream-water, $292\~2,244{\mu}g/g$ dry weight in suspended particulate from the seawater and $4.5\~27.2{\mu}g/g$ dry weight in the sediments. Although sterol compositions in sediments, seawater and stream-water were different, cholesterol was the predominant sterol in all samples. The proportion and concentration of coprostanol, a sewage tracer, in stream-water was much higher than those in sediment and seawater. The sterol levels including coprostanol in the sediments and seawater were higher at inner basin than at the outer bay. Some molecular indices and multivariate statistical analysis were used to assess the origin of these sterols and sewage contamination in the study area. The sterol composition patterns in stream-water were mainly associated with contamination by sewage-derived organic matters and those of seawater were associated with the activities of marine-originated organisms. Sterol levels in the sediments were both from the sewage input through stream-water and the marine- originated organisms. This survey suggests that the main source/route of sewage-derived organic matters in Masan Bay is the input of stream-water into the bay.

A Study on the Distributional Characteristic of Organic Matters on the Surface Sediments and Its Origin in Keogeum-sudo, Southern Part of Korean Peninsula (거금수도(居金水道) 표층퇴적물 중의 유기물 분포 및 기원에 관한 연구)

  • 윤양호
    • Journal of Environmental Science International
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    • v.9 no.2
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    • pp.137-144
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    • 2000
  • The observations on the seasonal fluctuation and distributional characteristic of organic matters on surface sediments and its origin were carried out at the 25 stations in Keogeum-sudo, southern coast of Korean Peninsula from February to October in 1993. I made an analysis on the environmental factors for surface sediments such as temperature, ignition loss, chemical oxygen demand, pheopigment, total sulphide, water content, mud content in grain size, COD/IL ratio and COD/sulphide ratio. The results are as follows ; 1) The range of temperature on the surface sediments was between 6.2${\circ}C$ and 24.6${\circ}C$. The highest mean temperatuer of mud was 24.0${\circ}C$ in summer, the lowest 6.6${\circ}C$ in winter. 2) Ignition loss(IL) fluctuated between 1.2% in winter and 16.8% in spring, that is to say, the seasons of increasing in temperature were very high ignition loss. 3) Chemical oxygen demand(COD) showed the highest mean value of 20.52 mg/g dry in summer within the range of 15/46~32.78 mg/g dry, while showed the lowest of 5.79 mg/g dry in winter within the range of 7.4~17.39 mg/g dry. 4) Pheopigment concentrations showed the highest mean value of 4.85 $\mu\textrm{g}$/g dry in autumn within the range of 0.84~9.21 $\mu\textrm{g}$/g dry, while it did the lowest mean value of 1.97 $\mu\textrm{g}$/g dry in summer within the range of 0.23~4.83 $\mu\textrm{g}$/g dry. 5) Total sulphide (H2S) fluctuated between no detect(ND) in spring, and 2.43 mg/g dry in sutumn. The highest mean value was 0.68 mg/g dry in sutumn, the lowest was 0.16 mg/g dry in spring. 6) Water content(WC) and mud content in grain size showed the mean value of 43.2% within the range of 26.5~59.7% and 91.0% within the range of 57.8~99.2%, respectively. 7) By the analytical results on the source of organic matter, it had been dumped from the seaweed farms in Keogeum-sudo coastal waters.

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