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Relation between the sedimentary organic record and the climatic oscilations in the Holocene attested by palynofacies and organic geochemical analyses from a pond of altitude in southern Brazil Anais da ABC (AABC)
GADENS-MARCON,GABRIELLI T.; MENDONÇA-FILHO,JOÃO G.; GUERRA-SOMMER,MARGOT; CARVALHO,MARCELO A.; PIRES,ETIENE F.; HARTMANN,LÉO A..
This paper presents the quantitative and qualitative results obtained from palynofacies and geochemistry analyses carried out on a core covering approximately 8000 years of sedimentation of a pond of altitude located at the mining district of Ametista do Sul, southernmost Brazil. The main objective of this paper is to consider the paleoclimatic and paleoenvironmental significance of these analyses. The hydrological isolation renders this pond climatically sensitive to variations in pluviometric regime and this enabled infer rainfall events during the early Holocene, which was responsible for the beginning of the processes of water accumulation in the gossan and the sedimentation of the pond. Changes in the pattern of moisture over the time become the drier...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Continental environment; Pond; Organic matter; Palynofacies analysis; Total organic carbon; Total sulfur.
Ano: 2014 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000301077
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La materia orgánica del suelo en seis agroecosistemas de la sabana de Huimanguillo, Tabasco. Colegio de Postgraduados
Murillo de la Rosa, Arnulfo.
Los suelos de la sabana de Huimanguillo, se localizan en lomeríos con pendientes ligeras, son de baja fertilidad, presentan alta acidez con pH que oscilan entre 4.0 a 5.5 y contenidos de materia orgánica de 1 a 4 %, a veces hasta de 20 %. La materia orgánica desempeña un papel importante en el suelo ya que aporta una gran variedad de elementos nutritivos para las plantas, y modifica la estructura del mismo, el conocimiento sobre su aporte de nutrientes es escaso, por lo que, las estimaciones del suministro al suelo se basan más bien en el rendimiento. El presente trabajo tuvo como objetivo estimar la densidad aparente (Dap), las reservas de carbono orgánico total (COT), nitrógeno total (Nt), la relación carbono nitrógeno (C/N), el carbono orgánico soluble...
Palavras-chave: Acrisol; Agroecosistemas; Densidad aparente; Carbono orgánico total; Nitrógeno total; Carbono orgánico soluble; Indice óptico y relación C/N; Agroecosystems; Bulk density; Total organic carbon; Total nitrogen; Soluble organic carbon; Optical index and C/N; Maestría; Producción Agroalimentaria en el Trópico.
Ano: 2010 URL: http://hdl.handle.net/10521/254
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Sea surface temperature, productivity, and terrestrial flux variations of the southeastern South China Sea over the past 800000 years (IMAGES MD972142) ArchiMer
Shiau, Liang-jian; Yu, Pai-sen; Wei, Kuo-yen; Yamamoto, Masanobu; Lee, Teh-quei; Yu, Ein-fen; Fang, Tien-hsi; Chen, Min-te.
Variations in sea surface temperature (SST), productivity, and biogenic components such as total organic carbon (TOC), carbonate, and opal contents measured from IMAGES (International Marine Global Changes Study) core MD972142 provide information about long-term paleoceanographic changes during the past similar to 870000 years in the southeastern South China Sea (SCS). MD972142 U-37(k)-SSTs varied from 25 to 29 degrees C, paralleling the glacial to interglacial changes. MD972142 biogenic components show relatively high carbonate and opal, and low TOC contents in interglacial stages, and low carbonate and opal and high TOC contents in glacial stages, and these variations appear to be sensitive to regional terrestrial sediment input and productivity. Our...
Tipo: Text Palavras-chave: Total organic carbon; Carbonate; Opal; Productivity; Sea surface temperature; South China Sea; Monsoon; IMAGES.
Ano: 2008 URL: https://archimer.ifremer.fr/doc/00237/34817/33682.pdf
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Isotopic composition and speciation of sedimentary nitrogen and carbon in the Okinawa Trough over the past 30 ka ArchiMer
Zheng, Li-wei; Hsiao, Silver Sung-yun; Ding, Xiao-dong; Li, Dawei; Chang, Yuan-pin; Kao, Shuh-ji.
Total organic carbon to total nitrogen ratios (C/N) and their isotopic compositions (δ13CTOC and δ15NTN) are oft-applied proxies to discern terrigenous from marine-sourced organics and to unravel ancient environmental information. In high depositional Asian marginal seas, the inclusion of N-bearing minerals in the bulk sediment dilutes or masks signals sought after in δ15N and δ13C analyses, thus leading to incorrect and even contradictory interpretations. We used KOH-KOBr to separate operationally defined total organic matter into oxidizable (labile) and residual fractions for content and isotope measurements. In a sediment core in the Okinawa Trough, significant amounts of carbon and nitrogen existed in the residual phase, in which the C/N ratio was ~9,...
Tipo: Text Palavras-chave: Carbon; Nitrogen; Isotope; Okinawa Trough; Sediment; Total organic carbon.
Ano: 2015 URL: https://archimer.ifremer.fr/doc/00295/40584/39503.pdf
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Foraminiferal oxygen isotope stratigraphy and high-resolution organic carbon, carbonate records from the Okinawa Trough - (IMAGES MD012404 and ODP site 1202) ArchiMer
Chang, Yp; Wu, Sm; Wei, Ky; Murayama, M; Kawahata, H; Chen, Mt.
Biogenic carbonate and organic carbon content of two deep sea cores (MD012404 and ODP site 1202) are measured to reconstruct surface ocean productivity variations in areas of the Okinawa Trough in the Western Pacific where the modern climate is highly sensitive to the East Asian monsoon and precipitation/river runoff. Based on foraminiferal isotope stratigraphy and AMS C-14 dating, the age models of the cores indicate that core MD012404 shows relatively low sedimentation rates with 50 cm ky(-1) on average, and that the sedimentation rates in core ODP 1202 are extremely high with an average of 500 cm ky(-1). Total organic carbon (TOC) and carbonate contents in core ODP 1202 are 0.56% and 6.80% on average, respectively, and are 0.62% and 15.86%,...
Tipo: Text Palavras-chave: IMAGES; ODP; Total organic carbon; Calcium carbonate; Okinawa Trough; Paleoceanography; Climate change; East Asian monsoon.
Ano: 2005 URL: https://archimer.ifremer.fr/doc/00229/34064/32627.pdf
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Reconstruction of productivity signal and deep-water conditions in Moroccan Atlantic margin (similar to 35 degrees N) from the last glacial to the Holocene ArchiMer
El Frihmat, Yassine; Hebbeln, Dierk; Jaaidi, E. L. Bachir; Mhammdi, Nadia.
In order to assess the changes in sea-surface hydrology and productivity signal from the last glacial to the Holocene; a set of isotopic, geochemical and microgranulometric proxies was used for this study. Former studies revealed that the reconstruction of paleoproductivity from ocean sediment gives different results depending the measurement used. The comparison between our productivity proxies (total organic carbon, carbonate and planktonic delta C-13) as well as previous results in nearby location indicates that the planktonic delta C-13 responds better to marine productivity changes and represents therefore a suitable proxy for paleoproductivity reconstruction in our studied area. The productivity signal reveals two main enrichments during the Young...
Tipo: Text Palavras-chave: Paleoproductivity; Larache margin; Late quaternary; Total organic carbon; Carbonate; Planktonic delta C-13.
Ano: 2015 URL: https://archimer.ifremer.fr/doc/00352/46274/46045.pdf
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Soil aggregation under different management systems Rev. Bras. Ciênc. Solo
Portella,Cibele Mascioli Rebello; Guimarães,Maria de Fátima; Feller,Christian; Fonseca,Inês Cristina de Batista; Tavares Filho,João.
Considering that the soil aggregation reflects the interaction of chemical, physical and biological soil factors, the aim of this study was evaluate alterations in aggregation, in an Oxisol under no-tillage (NT) and conventional tillage (CT), since over 20 years, using as reference a native forest soil in natural state. After analysis of the soil profile (cultural profile) in areas under forest management, samples were collected from the layers 0-5, 5-10, 10-20 and 20-40 cm, with six repetitions. These samples were analyzed for the aggregate stability index (ASI), mean weighted diameter (MWD), mean geometric diameter (MGD) in the classes &gt; 8, 8-4, 4-2, 2-1, 1-0.5, 0.5-0.25, and < 0.25 mm, and for physical properties (soil texture, water...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Aggregation indices; Aggregate size classes; Total organic carbon.
Ano: 2012 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000600021
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Carbon dynamics in no-till soil due to the use of industrial organic waste and mineral fertilizer Rev. Ciênc. Agron.
Romaniw,Jucimare; Sá,João Carlos de Moraes; Padilha,Alessandra Aparecida; Ramos,Fabrícia da Silva; Eurich,Guilherme; Bressan,Pamela Thaísa.
ABSTRACTThe use of organic waste from industrial processes in agriculture is a strategy not only for improving soil properties but also for promoting the utilization of recycled nutrients by market crops and for reducing environmental impact. The aim of this study was to evaluate the effects of using organic waste from pork and poultry slaughterhouses (OWS) applied alone or in combination with mineral fertilizer (MF) on the dynamics of soil organic matter (SOM) compartments. The experimental design adopted was that of completely randomized blocks with six treatments and three replicates. The treatments consisted of a general control (T1) without the addition of MF and OWS, the application of MF alone at 100% of the recommended fertilizer levels for the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Organic matter compartments; Total organic carbon.
Ano: 2015 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902015000300477
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