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Evaluating soil organic carbon and nutrient storage in a sustainable forest chestnut management context

Patrício, Maria do Sameiro; Nunes, Luís; Pereira, Ermelinda
Fonte: II European Congress on Chestnut Publicador: II European Congress on Chestnut
Tipo: Conferência ou Objeto de Conferência
ENG
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Forests fix carbon dioxide from the atmosphere and sequester it in biomass, timber products and soils (stock effect). Soil organic carbon (SOC) is the major stock of the terrestrial biosphere with great importance for the balance of carbon at the global scale. Nowadays, a reliable estimate of the stored C, in the mineral soil pool of forest ecosystems, is of great importance in helping Governments to make decisions in carrying out the Kyoto Protocol. In this study the quantification of C and nutrients stocks in the mineral-soil compartment for old high-forest Chestnut (Castanea sativa) stands was done. The study was developed in Northern Portugal in the mountains of Bornes and Marão (Regional level), from a more-Atlantic-to-less-maritime influence, where the species occupy a considerable area. In Portugal, the species is located essentially in the North from 400-1100 m above sea level. In the mountain areas, the coppices and high forest are particularly relevant, especially in deep forest soils. These chestnut ecosystems constitute discontinuities between conifer forests and are important for forest fire prevention, biodiversity, environmental protection as well as for timber production. Inventory information on SOC stocks is very scattered...

Dissolved organic carbon in rainwater from areas heavily impacted by sugar cane burning

COELHO, C. H.; FRANCISCO, J. G.; NOGUEIRA, R. F. P.; CAMPOS, M. L. A. M.
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
ENG
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This work reports on rainwater dissolved organic carbon (DOC) from Ribeirao Preto (RP) and Araraquara over a period of 3 years. The economies of these two cities, located in Sao Paulo state (Brazil), are based on agriculture and related industries, and the region is strongly impacted by the burning of sugar cane foliage before harvesting. Highest DOC concentrations were obtained when air masses traversed sugar cane fields burned on the same day as the rain event. Significant increases in the DOC volume weighted means (VWM) during the harvest period, for both sites, and a good linear correlation (r=0.83) between DOC and K (a biomass burning marker) suggest that regional scale organic carbon emissions prevail over long-range transport. The DOC VWMs and standard deviations were 272 +/- 22 mu mol L-1 (n=193) and 338 +/- 40 mu mol L-1 (n=80) for RP and Araraquara, respectively, values which are at least two times higher than those reported for other regions influenced by biomass burning, such as the Amazon. These high DOC levels are discussed in terms of agricultural activities, particularly the large usage of biogenic fuels in Brazil, as well as the analytical method used in this work, which includes volatile organic carbon when reporting DOC values. Taking into account rainfall volume...

Soil organic carbon dynamics in sugarcane crop in south-central Brazil; Dinâmica do carbono orgânico do solo na cultura da cana-de-açúcar na região centro-sul do Brasil

Olaya, Adriana Marcela Silva
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 17/07/2014 EN
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Sugarcane cropping is an important component of the Brazil´s economy. As the main feedstock used to produce ethanol, the area occupied with this crop has meaningfully increased in the last years and continues to expand in order to attend to the national and international demand of this biofuel. Despite that it has been demonstrated that land-use transition into sugarcane can negatively impact the soil carbon (C) dynamics, little is known about the effect of those land use changes (LUC) processes on the distribution of soil organic carbon (SOC) within particle-size classes, and how management practices in sugarcane can contribute to the C restoration. In this sense the main objective of this study was to evaluate through a modelling application the SOC dynamics in the sugarcane crop in response to LUC and different management scenarios. For a better understanding of LUC impact on C content in both particulate organic matter and mineral-associated fraction, we performed physical soil C fractionation in 34 study areas involving the three major land-use systems affected by sugarcane expansion. Also, biometric measurements were executed in sugarcane plant and ratoon crop in order to use those data in the model parameterization as well as to recalculate the payback time of the C debt through C conversion ratio reported in the literature. Finally...

Dissolved organic carbon in rainwater from areas heavily impacted by sugar cane burning

Coelho, C. H.; Francisco, J. G.; Nogueira, R. F. P.; Campos, M. L. A. M.
Fonte: Pergamon-Elsevier B.V. Ltd Publicador: Pergamon-Elsevier B.V. Ltd
Tipo: Artigo de Revista Científica Formato: 7115-7121
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Processo FAPESP: 03/01532-4; This work reports on rainwater dissolved organic carbon (DOC) from Ribeirao Preto (RP) and Araraquara over a period of 3 years. The economies of these two cities, located in São Paulo state (Brazil), are based on agriculture and related industries, and the region is strongly impacted by the burning of sugar cane foliage before harvesting. Highest DOC concentrations were obtained when air masses traversed sugar cane fields burned on the same day as the rain event. Significant increases in the DOC volume weighted means (VWM) during the harvest period, for both sites, and a good linear correlation (r=0.83) between DOC and K (a biomass burning marker) suggest that regional scale organic carbon emissions prevail over long-range transport. The DOC VWMs and standard deviations were 272 +/- 22 mu mol L-1 (n=193) and 338 +/- 40 mu mol L-1 (n=80) for RP and Araraquara, respectively, values which are at least two times higher than those reported for other regions influenced by biomass burning, such as the Amazon. These high DOC levels are discussed in terms of agricultural activities...

Dissolved organic carbon in rainwater: Glassware decontamination and sample preservation and volatile organic carbon

Campos, M. L. A. M.; Nogueira, R. F. P.; Dametto, P. R.; Francisco, J. G.; Coelho, C. H.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 8924-8931
ENG
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The efficiency of different methods for the decontamination of glassware used for the analysis of dissolved organic carbon (DOC) was tested using reported procedures as well as new ones proposed in this work. A Fenton solution bath (1.0 mmol L-1 Fe2+ and 100 mmol L-1 H2O2) for 1 h or for 30 min employing UV irradiation showed to combine simplicity, low cost and high efficiency. Using the optimized cleaning procedure, the DOC for stored UV-irradiated ultrapure water reached concentrations below the limit of detection (0.19 mu mol C L-1). Filtered (0.7 mu m) rain samples maintained the DOC integrity for at least 7 days when stored at 4 degrees C. The volatile organic carbon (VOC) fraction in the rain samples collected at two sites in São Paulo state (Brazil) ranged from 0% to 56% of their total DOC content. Although these high-VOC concentrations may be derived from the large use of ethanol fuel in Brazil, our results showed that when using the high-temperature catalytic oxidation technique, it is essential to measure DOC rather than non-purgeble organic carbon to estimate organic carbon, since rainwater composition can be quite variable, both geographically and temporally. (C) 2007 Elsevier Ltd. All rights reserved.

Nitrifying and heterotrophic population dynamics in biofilm reactors : effects of hydraulic retention time and the presence of organic carbon

Nogueira, R.; Melo, L. F.; Purkhold, Ulrike; Wuertz, Stefan; Wagner, Michael
Fonte: Elsevier Science Publicador: Elsevier Science
Tipo: Artigo de Revista Científica
Publicado em //2002 ENG
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Two biofilmreactors operated with hydraulic retention times of 0.8 and 5.0 h were used to study the links between population dynamics and reactor operation performance during a shift in process operation from pure nitrification to combined nitrification and organic carbon removal. The ammonium and the organic carbon loads were identical for both reactors. The composition and dynamics of the microbial consortia were quantified by fluorescence in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes combined with confocal laser scanning microscopy, and digital image analysis. In contrast to past research, after addition of acetate as organic carbon nitrification performance decreased more drastically in the reactor with longer hydraulic retention time. FISH analysis showed that this effect was caused by the unexpected formation of a heterotrophic microorganism layer on top of the nitrifying biofilm that limited nitrifiers oxygen supply. Our results demonstrate that extension of the hydraulic retention time might be insufficient to improve combined nitrification and organic carbon removal in biofilm reactors.; Ministério da Ciência, Tecnologia e Ensino Superior. Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS XXI BD/15943/98). Deutscher Akademischer Austauschdienst (A/99/06961). European Comission - T.M.R. BioToBio project. Deutsche Forschungsgemeinschaft .

Migration of dissolved organic carbon in biochars and biochar-mineral complexes

Lin,Yun; Munroe,Paul; Joseph,Stephen; Henderson,Rita
Fonte: Embrapa Informação Tecnológica; Pesquisa Agropecuária Brasileira Publicador: Embrapa Informação Tecnológica; Pesquisa Agropecuária Brasileira
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2012 EN
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677.3857%
The objective of this work was to determine the contribution of dissolved organic carbon (DOC) from a biochar mineral complex (BMC), so as to better understand the interactions between DOC, biochar, clay, and minerals during thermal treatment, and the effects of BMC on amended soils. The BMC was prepared by heating a mixture of a H3PO4-treated saligna biochar from Acacia saligna, clays, other minerals, and chicken manure. The BMC was applied to a sandy loam soil in Western Australia, where wheat was grown. Liquid chromatography-organic carbon detection (LC-OCD) tests were carried out on water extracts from the untreated biochar, the BMC, the BMC-amended soil, and on a control soil to measure the DOC concentration. LC-OCD tests provide a fingerprint of the DOC, which allows the fractions of DOC to be determined. Thermal processing enhanced the reaction of the A. saligna biochar with manure, clays and minerals, and affected the distribution of the DOC fractions. Notably, the process leads to immobilization of hydrophobic DOC and to an increase in the concentration of low-molecular-weight neutrals in the BMC. The application of the BMC to soil increases the DOC in the amended soil, especially the biopolymer fraction.

Dissolved Organic Carbon Determination Using FIA and Photo-Fenton Reaction

Kondo,Márcia M.; Arcos,Maria A. S. V.; Grassi,Marco T.
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2002 EN
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The FIA-photo-Fenton system is based on the flow oxidation of the organic matter. A small amount of the sample containing H2O2 is injected into the acidic flow solution of Fe2+, which passes through a tubular PTFE reactor irradiated with UV light. The generated CO2 is quantified by a conductometric detector and is directly proportional to the dissolved organic carbon concentration in the sample. The optimization studies were performed using EDTA solutions. The average recovery of organic carbon was 83% with a relative standard deviation of 3.7% using a 1:5 molar ratio of Fe2+:H2O2, pH 2.0, 100 muL of sample injection and a liquid flow of 1 mL min-1. After optimization, the DOC concentration was quantified using 13 different organic compounds, where the average recovery was 90%. The rate of the analysis was in average 50 samples hour-1.

Dial organic carbon fluctuations in a mangrove tidal creek in Sepetiba bay, Southeast Brazil

Rezende,CE.; Lacerda,LD.; Ovalle,ARC.; Silva,LFF.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2007 EN
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682.22266%
The carbon (C) concentration and flux, as dissolved organic carbon (DOC), particulate organic carbon (POC) and macrodetritus (MD), were quantified through 4 tidal cycles in a mangrove tidal creek in Southeastern Brazil. DOC was the major fraction of the total C concentration, accounting for 68 and 61% of the total C concentration during ebb and flood periods respectively. Concentrations of DOC (Ebb = 3,41 ± 0,57 mgC.L-1 and Flood = 3,55 ± 0,76 mgC.L-1) and POC (Ebb = 1,73 ± 0,99 mgC.L-1 and Flood = 1,28 ± 0,45 mgC.L-1) were relatively similar during the four tidal cycles. Macrodetritus presented a wide variation with concentration peaks probably related to external forces, such as winds, which enrich the ebb flow with leaf litter. DOC and POC fluxes depended primarily on tidal and net water fluxes, whereas MD fluxes were not. The magnitude of the DOC and POC fluxes varied with the area flooded at high tide, but not the MD fluxes. DOC was the major form of carbon export to Sepetiba Bay. During the four tidal cycles, the forest exported a total of 1,2 kg of organic carbon per ha, mostly as DOC (60%), followed by POC (22%) and MD (18%).

Migration of dissolved organic carbon in biochars and biochar-mineral complexes.

LIN, Y.; MUNROE, P.; JOSEPH, S.; HENDERSON, R.
Fonte: Pesquisa Agropecuária Brasileira, Brasília, DF, v.47, n.5, p.677-686, maio 2012. Publicador: Pesquisa Agropecuária Brasileira, Brasília, DF, v.47, n.5, p.677-686, maio 2012.
Tipo: Artigo em periódico indexado (ALICE)
EN
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The objective of this work was to determine the contribution of dissolved organic carbon (DOC) from a biochar mineral complex (BMC), so as to better understand the interactions between DOC, biochar, clay, and minerals during thermal treatment, and the effects of BMC on amended soils. The BMC was prepared by heating a mixture of a H3PO4‑treated saligna biochar from Acacia saligna, clays, other minerals, and chicken manure. The BMC was applied to a sandy loam soil in Western Australia, where wheat was grown. Liquid chromatography‑organic carbon detection (LC‑OCD) tests were carried out on water extracts from the untreated biochar, the BMC, the BMC‑amended soil, and on a control soil to measure the DOC concentration. LC‑OCD tests provide a fingerprint of the DOC, which allows the fractions of DOC to be determined. Thermal processing enhanced the reaction of the A. saligna biochar with manure, clays and minerals, and affected the distribution of the DOC fractions. Notably, the process leads to immobilization of hydrophobic DOC and to an increase in the concentration of low‑molecular‑weight neutrals in the BMC. The application of the BMC to soil increases the DOC in the amended soil, especially the biopolymer fraction.; 2012

Modelling and digital soil mapping of the organic carbon stock in the topsoil (0-10 cm) of Rio de Janeiro State, Brazil.

MENDONÇA-SANTOS, M. L.; SANTOS, H. G.; COELHO, M. R.
Fonte: In: GLOBAL WORKSHOP ON DIGITAL SOIL MAPPING, 3, 30 Sept. - Oct. 3, 2008, Logan, Utah. Bridging research, production, and environmental applications: papers. Publicador: In: GLOBAL WORKSHOP ON DIGITAL SOIL MAPPING, 3, 30 Sept. - Oct. 3, 2008, Logan, Utah. Bridging research, production, and environmental applications: papers.
Tipo: Artigo em anais de congresso (ALICE) Formato: 10 p.
EN
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A soil database with 431 soil profiles of Rio de Janeiro State was used in the scope of a research project entitled ?Quantifying the magnitude, spatial distribution and organic carbon in soils of Rio de Janeiro State, using quantitative modeling, GIS and database technologies? (Projeto Carbono_RJ, funded by FAPERJ - Carlos Chagas Filho Foundation for Research Support in Rio de Janeiro State). Considering that these soil data were collected to other purpose, there was only a few sparse data to soil bulk density, which is essential to estimate of soil organic carbon (SOC) stock. To face this problem, pedotransfer functions (PTFs) were estimated to be used in the modeling of organic soil carbon of topsoil (0-10 cm), using s.c.o.r.p.a.n model. The following environmental correlates were used as predictor variables: satellite data, lithology and soil maps, DEM (Digital Elevation Model) and its derivatives as source of information for these variables. This dataset, that represents the best organized soil dataset in Brazil, is working as a trial for learning/teaching of Digital Soil Mapping (DSM) using a variety of methods for predicting soil classes and their properties. The "f" of the equation was modeled by means of multilinear analysis and regression-kriging. Seven different models were built and compared through statistical methods. In a general way...

The hydrological flux of organic carbon at the catchment scale: a case study in the Cotter River catchment, Australia

Sabetraftar, Karim
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Thesis (Other)
EN
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688.99125%
Existing terrestrial carbon accounting models have mainly investigated atmosphere-vegetationsoil stocks and fluxes but have largely ignored the hydrological flux of organic carbon. It is generally assumed that biomass and soil carbon are the only relevant pools in a landscape ecosystem. However, recent findings have suggested that significant amounts of organic carbon can dissolve (dissolved organic carbon or DOC) or particulate (particulate organic carbon or POC) in water and enter the hydrological flux at the catchment scale. A significant quantity of total organic carbon (TOC) sequestered through photosynthesis may be exported from the landscape through the hydrological flux and stored in downstream stocks.¶ This thesis presents a catchment-scale case study investigation into the export of organic carbon through a river system in comparison with carbon that is produced by vegetation through photosynthesis. The Cotter River Catchment was selected as the case study. It is a forested catchment that experienced a major wildfire event in January 2003. The approach is based on an integration of a number of models. The main input data were time series of in-stream carbon measurements and remotely sensed vegetation greenness. The application of models to investigate diffuse chemical substances has dramatically increased in the past few years because of the significant role of hydrology in controlling ecosystem exchange. The research firstly discusses the use of a hydrological simulation model (IHACRES) to analyse organic carbon samples from stream and tributaries in the Cotter River Catchment case study. The IHACRES rainfall-runoff model and a regionalization method are used to estimate stream-flow for the 75 sub-catchments. The simulated streamflow data were used to calculate organic carbon loads from concentrations sampled at five locations in the catchment.¶ ...

Mercury and organic carbon distribution in six lakes from the North of Rio de Janeiro State

Sousa,Wanderson Primo de; Carvalho,Carlos Eduardo Veiga de; Carvalho,Claudia Calasans Veiga de; Suzuki,Marina Satika
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2004 EN
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677.8687%
The objectives of the study was to evaluate the mercury contamination in sediments of six lagoons located in the north region of Rio de Janeiro State, trying to relate the Hg concentrations with factors that could influence it's mobility, such as organic carbon. The highest values observed in the superficial sediments in lakes like Campelo (349,6 µg.kg -1) suggested a recent Hg input into the system. The correlation Hg/Organic carbon was positive for most areas, indicating that the organic carbon was a significant parameter for Hg retention in this region. The obtained results suggested that the mercury used as fungicide in agriculture lands and in gold mining areas in the past were probably responsible for the contamination of this environment.

Dissolved and suspended organic carbon in the Atlantic sector of the Southern Ocean. Stock dynamics in upper ocean waters

Doval, M. Dolores; Álvarez-Salgado, Xosé Antón; Gasol, Josep M.; Lorenzo, Luisa M.; Mirón, Iván; Figueiras, F. G.; Pedrós-Alió, Carlos
Fonte: Inter Research Publicador: Inter Research
Tipo: Artículo Formato: 918459 bytes; application/pdf
ENG
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12 pages, 6 figures, 3 tables.; Dissolved and suspended organic carbon (DOC and POC) distributions were studied in the undersampled Atlantic sector of the Southern Ocean during Cruise HE052 of the ŒBio Hespérides¹ in December 1998. The coastal waters of the ice edge, the Gerlache Strait, and the open-ocean waters of the Weddell Sea and the Drake Passage were sampled. The high correlation between chlorophyll a (chl a), DOC and POC suggest that a considerable fraction (estimated at 15 to 30%) of the organic matter available in the upper mixed layer of the different study regions is the product of synthesis and early degradation of planktonic primary production. Relatively low renewal times (≤2 wk) of this material, except in the Polar Front Zone (>5 were deduced from measured primary/bacterial production rates. Maximum contributions of this potentially bioreactive organic carbon pool (TOCB) to the total organic carbon (TOC) were observed in the highly productive waters of the ice edge (24%) and Gerlache Strait (30%) regions, where high chl a levels and shallow upper mixed layers (due to marked salinity gradients) occurred. DOC represented 42 and 56% of TOCB, in these regions, respectively. In contrast, TOCB comprised ≤20% of TOC in the less productive open-ocean waters of the Weddell Sea and Drake Passage...

Organic carbon and nitrogen losses influenced by vegetation removal in a semiarid mediterranean soil

Martínez-Mena García, M. Dolores; Álvarez-Rogel, José; Castillo Sánchez, Victor Manuel; Albaladejo Montoro, Juan
Fonte: Springer Publicador: Springer
Tipo: Artículo Formato: 579917 bytes; image/jpeg
ENG
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A reduction in plant cover can lead to an increase in the erosionprocesses that diminish soil quality. Any rise in temperature resulting frompredicted climate changes may aggravate this effect, particularly in semiaridMediterranean areas. Bearing this in mind, the capacity of a soil to preserveorganic matter becomes very important if the soil is to maintain its physicaland chemical properties. Soil organic carbon and nitrogen changes wereevaluatedin a non-disturbed (with natural vegetation) and a disturbed (all vegetationmanually clipped to ground level) pine system. Nine years after vegetationremoval significant differences (p < 0.01) were found in the soil organiccarbon content between plots (top 20 cm), but not in totalnitrogen. In the disturbed plot 0.0232 Mg ha–1y–1 of soil organic carbon were lost through erosionand4.30 Mg ha–1 y–1 throughmineralization. In the first 48 months after vegetation removal the soilorganiccarbon content fell from 40.3 to 28.0 g kg–1. Inthe last 60 months of the experiment the amount of organic carbon in the soilfell from 28.0 to 27.7 g kg–1. This result wasmainly attributable to the intense oxidization, which took place during thefirst 60 months, of organic matter linked to the coarse soil mineral fraction.Up to the 72nd month the losses by erosion were a total of 532.7g...

Organic carbon distribution and water column respiration in the NW Africa-Canaries Coastal Transition Zone

Arístegui, Javier; Barton, Eric D.; Montero, María F.; García-Muñoz, Mercedes; Escánez, José
Fonte: Inter Research Publicador: Inter Research
Tipo: Artículo Formato: 833898 bytes; application/pdf
ENG
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13 pages, 8 figures, 2 tables.; The Canary Current (CC) is characterised by strong disruption of its flow by the Canaries Archipelago, which extends across the prevailing flow. In the Coastal Transition Zone (CTZ) downstream of the islands, a region of high mesoscale activity connects the eutrophic waters of the NW Africa coastal upwelling (UW) system with the oligotrophic open ocean waters of the eastern subtropical North Atlantic gyre (ESNA). We studied the distribution of particulate (POC) and dissolved organic carbon (DOC) and carbon remineralization rates in the 0 to 1000 m water column of this transitional region to assess its role in horizontal and vertical export of organic matter. The epipelagic waters (0 to 200 m) of the CTZ are characterised by higher mean surface integrated concentrations of POC (0.8 ± 0.4 mol C m-2) and DOC (17 ± 7 mol C m-2), and by higher community respiration (R >100 mmol C m-2 d-1) than the ESNA or UW waters. Integrated R was much lower (7 ± 3 mmol C m-2 d-1) in the mesopelagic zone (200 to 1000 m), indicating that most of the organic matter was respired in the upper 200 m, with little being transported downwards. Nevertheless, peaks in DOC and R were observed at 300 to 600 m depth, coinciding with the depth of the deep scattering layer. These relative maxima were particularly important in the case of DOC...

Monitoring the natural processing of organic carbon and phenols in selective wetlands within Monroe County, NY

Rubaiyat, Muhammad
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
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Dissolved Organic Carbon (DOC) is one of the largest active organic carbon reservoirs formed from processes that break down terrestrial/aquatic matter and released from plant roots as exudates. In watersheds, DOC is continuously transported and processed through rivers, streams and lakes. DOC is present in wetlands around Monroe County, New York; in areas that function as groundwater recharge, stormwater retention, nutrient retention and habitats for wildlife. The conducted research was an initial step towards a more thorough understanding of DOC's processing, especially in regard to its phenolic content, in small urban/sub-urban wetlands in Monroe County, NY. DOC and phenol concentrations were assessed primarily through utilizing a Total Organic Carbon (TOC) analyzer and the Folin-Ciocalteau Reagent method. Ultimately, samples of influent flow to, and effluent flow from, natural, man-made and retention pond wetlands were collected and analyzed to help understand how DOC might be processed through these local wetlands. Results show that there was no statistical difference in the DOC and Phenol Net Concentration difference among wetland types and seasons but statistical significance existed only in the comparison of the total overall DOC and Phenol concentrations among Seasons...

Processo sedimentar atual e a distribuição de carbono e nitrogênio orgânicos no Canal de São Sebastião (SP) e plataforma continental interna adjacente; Modern sedimentary processes and the distribution of organic carbon and nitrogen in São Sebastião Channel (SP) and adjacent inner shelt

Barcellos, Roberto Lima; Furtado, Valdenir Veronese
Fonte: Universidade de São Paulo. Instituto Oceanográfico Publicador: Universidade de São Paulo. Instituto Oceanográfico
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 01/01/1999 POR
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As distribuições sedimentares no Canal de São Sebastião e na plataforma interna adjacente, avaliadas através da granulometria e das concentrações de matéria orgânica sedimentar, indicaram a presença de baixos teores de carbono e nitrogênio orgânicos, associados ao pequeno aporte de material e à hidrodinâmica da área. Os maiores teores no Canal de São Sebastião decorrem de aportes pontuais de origem antrópica, associados à efluentes de emissários submarinos e atividades de portos na sua região central e da dinâmica e topografia de fundo do canal, que criam áreas de baixa energia, permitindo a deposição de pelitos e a retenção de matéria orgânica. Na plataforma continental a sudoeste da Ilha de São Sebastião, os baixos teores de matéria orgânica estão associados à ação de ondas sobre o fundo, que retrabalham os sedimentos impedindo a preservação da mesma e ao baixo aporte orgânico, decorrente de drenagens costeiras incipientes e da presença de massas d'água oligotróficas. A leste e sudeste da ilha, que atua como barreira à ação de ondas e como fonte de material, observa-se a presença de finos e de maiores teores de matéria orgânica. A ingressão da Água Central do Atlântico Sul (ACAS) pode ocasionar o aumento localizado de nitrogênio orgânico na área.; The sedimentary distribution in São Sebastião Channel and adjacent inner shelf...

Influence of land crabs Gecarcinus quadratus (Gecarcinidae) on distributions of organic carbon and roots in a Costa Rican rain forest

Sherman,Peter M
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2006 EN
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In Costa Rica’s Corcovado National Park,the fossorial land crab, Gecarcinus quadratus (Gecarcinidae), densely populates (1-6 m-2) a region of forest extending from the Park’s Pacific coastline inland to ca.600 m. Throughout this coastal forest (‘crabzone’), crabs selectively forage for fallen leaves and relocate them to subterranean burrow chambers. Comparisons between surface soils (0 -15 cm) sampled from the crabzone and forest lying immediately inland that is naturally devoid of crabs (‘crabless zone’) suggest that crabzone top soils contained less organic carbon and fewer fine and very fine roots. In contrast, soils sampled from 70 -100 cm depths in the crabzone contained twice the carbon of the crabless zone during the dry season but similar values during the wet season. Two years of experimental crab exclusion from 25 m² replicates established in the crabzone resulted in 16% more organic carbon content in surface soils relative to baseline conditions (n.s.) and 22% more carbon than final control values (P <0.05).Excavations of burrow chambers, with an average (±SD) depth of 48 ±12 cm, indicated localized, subterranean pockets of elevated (+60 %) organic carbon and increased densities of fine and very fine roots relative to same-depth samples from the crabzone unassociated with burrows chambers. Rev. Biol. Trop. 54 (1): 149-161. Epub 2006 Mar 31.

Black carbon and organic carbon emissions from wildfires in Mexico

CRUZ NÚÑEZ,XÓCHITL; VILLERS RUIZ,LOURDES; GAY GARCÍA,CARLOS
Fonte: Centro de Ciencias de la Atmósfera, UNAM Publicador: Centro de Ciencias de la Atmósfera, UNAM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2014 EN
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In Mexico, approximately 7650 wildfires occur annually, affecting 263 115 hectares of land. In addition to their impact on land degradation, wildfires cause deforestation, damage to ecosystems and promote land use change; apart from being the source of emissions of toxic substances to the environment (i.e., hydrogen cyanide, black carbon and organic carbon). Black carbon is a short-lived greenhouse pollutant that also promotes snow and ice melting and decreased rainfall; it has an estimated global warming potential close to 5000.¹ We present an estimate of the black carbon and organic carbon emissions from wildfires in Mexico from 2000 to 2012 using selected emission factors from the literature and activity data from local agencies. The results show average emissions of 5955 Mg/yr for black carbon and 62 085 Mg/yr for organic carbon. Black carbon emissions are estimated to be 14 888 Gg CO2 equivalent (CO2 eq) per year on average. With proper management of wildfires, such emissions can be mitigated. Moreover, improved air quality, conservation of ecosystems, improvement of visibility and maintenance of land use are a subset of the related co-benefits. Mitigating forest organic carbon emissions, which are ten times higher than black carbon emissions...