scholarly journals Supplementary material to "Distinctive effects of allochthonous and autochthonous organic matter on CDOM spectra in a tropical lake"

2018 ◽  
Author(s):  
Luciana Pena Mello Brandão ◽  
Ludmila Silva Brighenti ◽  
Peter Anton Staehr ◽  
Eero Asmala ◽  
Philippe Massicotte ◽  
...  
Keyword(s):  
Organic Matter ◽  
Tropical Lake ◽  
Autochthonous Organic Matter ◽  
Supplementary Material

scholarly journals Distinctive effects of allochthonous and autochthonous organic matter on CDOM spectra in a tropical lake

2018 ◽  
Author(s):  
Luciana Pena Mello Brandão ◽  
Ludmila Silva Brighenti ◽  
Peter Anton Staehr ◽  
Eero Asmala ◽  
Philippe Massicotte ◽  
...  
Keyword(s):  
Organic Matter ◽  
Light Absorption ◽  
Spectral Characteristics ◽  
Light Availability ◽  
Principal Component ◽  
Tropical Lake ◽  
Tropical Lakes ◽  
Spectral Indices ◽  
Chl A ◽  
Autochthonous Organic Matter

Abstract. Despite the increasing understanding about differences in carbon cycling between temperate and tropical freshwater systems, our knowledge on the importance of organic matter (OM) pools on light absorption properties in tropical lakes is very scarce. We performed a factorial mesocosm experiment in a tropical lake (Minas Gerais, Brazil) to evaluate the effects of increased concentrations of allochthonous and autochthonous OM on the light absorption characteristics of colored dissolved organic matter (CDOM), in addition to differences in light availability. We added inorganic nutrients (to stimulate OM autochthonous production by phytoplankton growth) and allochthonous OM, and also introduced shading. Dissolved organic carbon (DOC), Chl-a, nutrients, total suspended solid concentrations (TSM) and spectral CDOM absorption were measured every three days to evaluate how they responded to these treatments. CDOM quality was characterized by spectral indices (S250–450, S275–295, S350–450, SR and SUVA254). The effect of carbon sources on the spectral CDOM absorption was investigated through principal component (PCA) and redundancy (RDA) analyses. The two different OM sources affected CDOM quality differently. Spectral indices (S250–450 and SR) were mostly affected by allochthonous OM addition. The PCA showed that enrichment by allochthonous carbon had a strong effect on the CDOM spectra in the range between 300 and 400 nm, while the increase of autochthonous carbon increased absorption at wavelengths below 350 nm. Our results show that small inputs of allochthonous OM have much larger effects on the spectral characteristics on the lake CDOM, compared to large production of autochthonous OM.

scholarly journals Distinctive effects of allochthonous and autochthonous organic matter on CDOM spectra in a tropical lake

2018 ◽  
Vol 15 (9) ◽  
pp. 2931-2943 ◽  
Author(s):  
Luciana Pena Mello Brandão ◽  
Ludmila Silva Brighenti ◽  
Peter Anton Staehr ◽  
Eero Asmala ◽  
Philippe Massicotte ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carbon Cycling ◽  
Light Absorption ◽  
Light Availability ◽  
Principal Component ◽  
Tropical Lake ◽  
Tropical Lakes ◽  
Spectral Indices ◽  
Chl A ◽  
Autochthonous Organic Matter

Abstract. Despite the increasing understanding about differences in carbon cycling between temperate and tropical freshwater systems, our knowledge on the importance of organic matter (OM) pools on light absorption properties in tropical lakes is very scarce. We performed a factorial mesocosm experiment in a tropical lake (Minas Gerais, Brazil) to evaluate the effects of increased concentrations of allochthonous and autochthonous OM, and differences in light availability on the light absorption characteristics of chromophoric dissolved organic matter (CDOM). Autochthonous OM deriving from phytoplankton ( ∼  Chl a) was stimulated by addition of nutrients, while OM from degradation of terrestrial leaves increased allochthonous OM, and neutral shading was used to manipulate light availability. Effects of the additions and shading on DOC, Chl a, nutrients, total suspended solid concentrations (TSM) and spectral CDOM absorption were monitored every 3 days. CDOM quality was characterized by spectral indices (S250–450, S275–295, S350–450, SR and SUVA254). Effects of carbon sources and shading on the spectral CDOM absorption was investigated through principal component (PCA) and redundancy (RDA) analyses. The two different OM sources affected CDOM quality very differently and shading had minor effects on OM levels, but significant effects on OM quality, especially in combination with nutrient additions. Spectral indices (S250–450 and SR) were mostly affected by allochthonous OM addition. The PCA showed that enrichment by allochthonous carbon had a strong effect on the CDOM spectra in the range between 300 and 400 nm, while the increase in autochthonous carbon increased absorption at wavelengths below 350 nm. Our study shows that small inputs of allochthonous OM can have large effects on the spectral light absorption compared to large production of autochthonous OM, with important implications for carbon cycling in tropical lakes.

scholarly journals Supplementary material to "Organic matter across subsea permafrost thaw horizons on the East Siberian Arctic Shelf"

2018 ◽  
Author(s):  
Birgit Wild ◽  
Natalia Shakhova ◽  
Oleg Dudarev ◽  
Alexey Ruban ◽  
Denis Kosmach ◽  
...  
Keyword(s):  
Organic Matter ◽  
Arctic Shelf ◽  
Permafrost Thaw ◽  
Siberian Arctic ◽  
Supplementary Material ◽  
Subsea Permafrost

scholarly journals Supplementary material to "A 21,000 year record of organic matter quality in the WAIS Divide ice core"

2016 ◽  
Author(s):  
Juliana D'Andrilli ◽  
Christine M. Foreman ◽  
Michael Sigl ◽  
John C. Priscu ◽  
Joseph R. McConnell
Keyword(s):  
Organic Matter ◽  
Ice Core ◽  
Organic Matter Quality ◽  
Supplementary Material

Molecular and petrographical evidence for lacustrine environmental and biotic change in the palaeo-Sichuan mega-lake (China) during the Toarcian Oceanic Anoxic Event

2021 ◽  
pp. SP514-2021-2
Author(s):  
Weimu Xu ◽  
Johan W. H. Weijers ◽  
Micha Ruhl ◽  
Erdem F. Idiz ◽  
Hugh C. Jenkyns ◽  
...  
Keyword(s):  
Organic Matter ◽  
Sichuan Basin ◽  
Large Scale ◽  
Algal Growth ◽  
Black Shales ◽  
Content Type ◽  
Oceanic Anoxic Event ◽  
Anoxic Event ◽  
Supplementary Material ◽  
The Sichuan Basin

AbstractThe organic-rich upper Lower Jurassic Da'anzhai Member (Ziliujing Formation) of the Sichuan Basin, China is the first stratigraphically well-constrained lacustrine succession associated with the Toarcian Oceanic Anoxic Event (T-OAE; ∼183 Ma). The formation and/or expansion of the Sichuan mega-lake, likely one of the most extensive fresh-water systems to have existed on the planet, is marked by large-scale lacustrine organic productivity and carbon burial during the T-OAE, possibly due to intensified hydrological cycling and nutrient supply. New molecular biomarker and organic petrographical analyses, combined with bulk organic and inorganic geochemical and palynological data, are presented here, providing insight into aquatic productivity, land-plant biodiversity, and terrestrial ecosystem evolution in continental interiors during the T-OAE. We show that lacustrine algal growth during the T-OAE accounted for a significant organic-matter flux to the lakebed in the palaeo-Sichuan mega-lake. Lacustrine water-column stratification during the T-OAE facilitated the formation of dysoxic-anoxic conditions at the lake bottom, favouring organic-matter preservation and carbon sequestration into organic-rich black shales in the Sichuan Basin. We attribute the palaeo-Sichuan mega-lake expansion to enhanced hydrological cycling in a more vigorous monsoonal climate in the hinterland during the T-OAE greenhouse.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5433544

Lead, zinc and arsenic contamination of pit lake waters in the Zeida abandoned mine (High Moulouya, Morocco)

2021 ◽  
pp. geochem2021-009
Author(s):  
Lamiae EL ALAOUI ◽  
Abdelilah Dekayir ◽  
Mohammed Rouai ◽  
EL Mehdi Benyassine
Keyword(s):  
Organic Matter ◽  
Iron Oxides ◽  
Environmental Issues ◽  
Abandoned Mine ◽  
Equal Proportion ◽  
Pit Lake ◽  
Content Type ◽  
Link Type ◽  
Supplementary Material ◽  
Lake Waters

In the Zeida abandoned mine, pit lake waters exhibit alkaline pH and high conductivity. The concentrations of the total dissolved lead and zinc are very low due to their adsorption on clay minerals and iron oxyhydroxides. Conversely, arsenic concentrations in two lakes (ZL1 and ZA) exceeded WHO water quality guidelines. The As content is relatively high in ZL1 lake and exists mainly as As(V). In ZA lake, As(III) occurs in low concentration compared to the total dissolved arsenic, while dimethylarsenic acid [H2AsO2(CH3)2, DMA) prevails. This means that arsenic was methylated by organic matter produced by microorganisms such as chlorella. The sequential extraction of floor sediments in two lakes shows that the bioavailable arsenic contents change between the two lakes. In ZA lake, the sediments show high concentrations of lead and arsenic compared to ZL1 sediment since it is surrounded by mining waste tailings, which are rich in such chemical elements. An arsenic leaching test of ZA sediment shows that bioavailable arsenic is distributed in equal proportion between clay/carbonates, sulfide-organic matter, and iron oxides (HFO) phases, while in ZL1, most of the arsenic is linked to hydrous iron oxides (HFO).Thematic collection: This article is part of the Hydrochemistry related to exploration and environmental issues collection available at: https://www.lyellcollection.org/cc/hydrochemistry-related-to-exploration-and-environmental-issuesSupplementary material:https://doi.org/10.6084/m9.figshare.c.5545316

An integrated organic–inorganic geochemical characterization of Paleogene sediments in No.1 Structural Belt of the Nanpu Sag, Bohai Bay Basin, eastern China: implications for the origin of organic matter

2020 ◽  
Vol 21 (1) ◽  
pp. geochem2019-060
Author(s):  
Yu Guo ◽  
Wenzhe Gang ◽  
Gang Gao ◽  
Shangru Yang ◽  
Chong Jiang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Higher Plants ◽  
Eastern China ◽  
Source Rocks ◽  
Bohai Bay ◽  
Type Ii ◽  
Lacustrine Environment ◽  
Anoxic Conditions ◽  
Supplementary Material ◽  
Nanpu Sag

Paleogene sediments, especially the third member of the Dongying Formation (Ed3) and the first and third members of the Shahejie Formation (Es1 and Es3), have been regarded as the most important source rocks in the Nanpu Sag. Organic and inorganic analyses, including Rock-Eval pyrolysis, gas chromatography-mass spectrometry, and element geochemistry, in 91 mudstone samples, were used to reconstruct the palaeoenvironmental conditions, such as palaeoclimate, palaeo-salinity and palaeo-redox conditions, and to recognize the origin of organic matter. The results show that Es3 has a higher TOC content than Es1 and Ed3. Hydrocarbon genetic potential (S1 + S2) of the samples indicate fair to good hydrocarbon potential. The kerogen type of Ed3 and Es1 source rocks are Type II1–II2, while Es3 source rocks are dominated by Type II2–III kerogens. Biomarkers and inorganic geochemical indicatives of source rocks, such as Pr/Ph, V/(V + Ni) and Cu/Zn, indicate a lacustrine environment with fresh to brackish water under suboxic to anoxic conditions during deposition. Ed3 source rocks are characterized by low G/C30H (gamacerane/C30hopane) (<0.1), TT/C30H (tricyclic terpane/C30hopane) and S/H (serane/hopane), high Pr/Ph (pristane/phytane) and C24TeT/C23TT (C24tetracyclic terpane/C23tricyclic terpane), indicating mixed input of both algae and terrestrial higher plants, dominated by terrestrial higher plants. Es1 source rocks display medium G/C30H, TT/C30H, S/H, Pr/Ph and C24TeT/C23TT, indicative of a mixed input of both algae and terrestrial higher plants. Es3 source rocks are characterized by high G/C30H (>0.1), TT/C30H and S/H, low Pr/Ph and C24TeT/C23TT, typical of a mixed input of algae and terrestrial higher plants, with algal dominance. Ed3, Es1 and Es3 source rocks were mostly deposited in semi-arid to humid-warm climate conditions, with an average temperature higher than 15°C. This study suggests that suitable temperatures, a fresh to brackish lacustrine environment and suboxic to anoxic conditions could result in a high organic matter concentration and preservation, thus providing prerequisites for the formation of high-quality source rocks.Supplementary material: Tables S1–S3 are available at https://doi.org/10.6084/m9.figshare.c.5227684

scholarly journals Organo-Mineral Interactions Are More Important for Organic Matter Retention in Subsoil Than Topsoil

Soil Systems ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 4 ◽  
Author(s):  
Vincent Poirier ◽  
Isabelle Basile-Doelsch ◽  
Jérôme Balesdent ◽  
Daniel Borschneck ◽  
Joann K. Whalen ◽  
...  
Keyword(s):  
Organic Matter ◽  
Crop Residue ◽  
Crop Residues ◽  
Clay Content ◽  
X Ray Diffraction ◽  
Density Fractions ◽  
Organic Matter Concentration ◽  
Fractionation Procedure ◽  
Autochthonous Organic Matter ◽  
C And N

Decomposing crop residues contribute to soil organic matter (SOM) accrual; however, the factors driving the fate of carbon (C) and nitrogen (N) in soil fractions are still largely unknown, especially the influence of soil mineralogy and autochthonous organic matter concentration. The objectives of this work were (1) to evaluate the retention of C and N from crop residue in the form of occluded and mineral-associated SOM in topsoil (0–20 cm) and subsoil (30–70 cm) previously incubated for 51 days with 13C-15N-labelled corn residues, and (2) to explore if specific minerals preferentially control the retention of residue-derived C and N in topsoil and subsoil. We used topsoil and subsoil having similar texture and mineralogy as proxies for soils being rich (i.e., topsoil) and poor (i.e., subsoil) in autochthonous organic matter. We performed a sequential density fractionation procedure and measured residue-derived C and N in occluded and mineral-associated SOM fractions, and used X-ray diffraction analysis of soil density fractions to investigate their mineralogy. In accordance with our hypothesis, the retention of C and N from crop residue through organo-mineral interactions was greater in subsoil than topsoil. The same minerals were involved in the retention of residue-derived organic matter in topsoil and subsoil, but the residue-derived organic matter was associated with a denser fraction in the subsoil (i.e., 2.5–2.6 g cm−3) than in the topsoil (i.e., 2.3–2.5 g cm−3). In soils and soil horizons with high clay content and reactive minerals, we find that a low SOM concentration leads to the rapid stabilization of C and N from newly added crop residues.

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