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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Essays on land-use change, carbon sequestration and emissions in China /

Li, Man. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2011. / Printout. Includes bibliographical references (leaves 126-132). Also available on the World Wide Web.
152

Individual tree detection and modelling above-ground biomass and forest parameters using discrete return airborne LiDAR data

Wan Mohd Jaafar, Wan Shafrina Binti January 2018 (has links)
Individual tree detection and modelling forest parameters using Airborne Laser Scanner data (Light Detection and Ranging (LiDAR) is becoming increasingly important for the monitoring and sustainable management of forests. Remote sensing has been a useful tool for individual tree analysis in the past decade, although inadequate spatial resolution from satellites means that only airborne systems have sufficient spatial resolution to conduct individual tree analysis. Moreover, recent advances in airborne LiDAR now provide high horizontal resolution as well as information in the vertical dimension. However, it is challenging to fully exploit and utilize small-footprint LiDAR data for detailed tree analysis. Procedures for forest biomass quantification and forest attributes measurement using LiDAR data have improved at a rapid pace as more robust and sophisticated modelling used to improve the studies. This thesis contains an evaluation of three approaches of utilizing LiDAR data for individual tree forest measurement. The first explores the relationship between LiDAR metrics and field reference to assess the correlation between LiDAR and field data at the individual-tree level. The intention was not to detect trees automatically, but to develop a LiDAR-AGB model based on trees that were mapped in the field so as to evaluate the relationships between LiDAR-type metrics under controlled conditions for the study sites, and field-derived AGB. A non-linear AGB model based on field data and LiDAR data was developed and LiDAR height percentile h80 and crown width measurement (CW) was found to best fit the data as evidenced by and Adj-R2 value of 0.63, the root mean squared error of the model of 14.8% and analysis of the residuals. This paper provides the foundation for a predictive LiDAR-AGB model at tree level over two study sites, Pasoh Forest Reserve and FRIM Forest Reserve. The second part of the thesis then takes this AGB-LiDAR relationship and combines it with individual tree crown delineation. This chapter shows the contribution of performing an automatic individual tree crown delineation over the wider forest areas. The individual tree crown delineation is composed of a five-step framework, which is unique in its automated determination of dominant crown sizes in a forest area and its adaption of the LiDAR-AGB model developed for the purpose of validation the method. This framework correctly delineated 84% and 88% of the tree crowns in the two forest study areas which is mostly dominated with lowland dipterocarp trees. Thirdly, parametric and non-parametric modelling approaches are proposed for modelling forest structural attributes. Selected modelling methods are compared for predicting 4 forest attributes, volume (V), basal area (BA), height (Ht) and aboveground biomass (AGB) at the species level. The AGB modelling in this paper is extracted using the LiDAR derived variables from the automated individual tree crown delineation, in contrast to the earlier AGB modelling where it is derived based on the trees that were mapped in the field. The selected non-parametric method included, k-nearest neighbour (k-NN) imputation methods: Most Similar Neighbour (MSN) and Gradient Nearest Neighbour (GNN), Random Forest (RF) and parametric approach: Ordinary Least Square (OLS) regression. To compare and evaluate these approaches a scaled root mean squared error (RMSE) between observed and predicted forest attribute sampled from both forest site was computed. The best method varied according to response variable and performance measure. OLS regression was to found to be the best performance method overall evidenced by RMSE after cross validation for BA (1.40 m2), V (1.03 m3), Ht (2.22 m) and AGB (96 Kg/tree) respectively, showed its applicability to wider conditions, while RF produced best overall results among the non-parametric methods tested. This thesis concludes with a discussion of the potential of LiDAR data as an independent source of important forest inventory data source when combined with appropriate designed sample plots in the field, and with appropriate modelling tools.
153

The potential for root trait selection to enhance soil carbon storage and sustainable nutrient supply

Mwafulirwa, Lumbani January 2017 (has links)
Plant roots are central to C- and N-cycling in soil. However, (i) plants differ strongly in tissue recalcitrance (e.g. lignin content) affecting their mineralization in soil, and (ii) rhizodeposits also vary strongly in terms of the metabolites that they contain. Therefore, (i) we used 13C labelled ryegrass root and shoot residues as substrates to investigate the impact of tissue recalcitrance on soil processes through controlled incubation of soil, (ii) we assessed variations in root C-deposition between barley genotypes and their respective impacts on soil processes using 13CO2 labelled plants, (iii) using 13C/15N enriched ryegrass root residues as tracer material, we investigated the impacts of barley genotypes on mineralization of recently incorporated plant residues in soil and plant uptake of the residue-derived N, and (iv) we applied a quantitative trait loci analysis approach to identify barley chromosome regions affecting soil microbial biomass and other soil and root related traits. In the first study, addition of root residues resulted in reduced C-mineralization rates, soil microbial activity and soil organic matter (SOM) priming relative to shoot residues. Planted experiments revealed (i) genotype effects on plant-, SOM- and residuederived surface soil CO2-C efflux and showed that incorporation of plant derived-C to the silt-and-clay soil fraction varied between genotypes, indicating relative stabilization of root derived-C as a result of barley genotype, (ii) that plant uptake of residue released N between genotypes was linked to genotype impacts on residue mineralization, and (iii) barley chromosome regions that influence plant-derived microbial biomass C. These results (i) suggest that greater plant tissue recalcitrance can lower soil C-emissions and increase C-storage in soil, and (ii) demonstrate the barley genetic influence on soil microbial communities and C- and N-cycling, which could be useful in crop breeding to improve soil microbial interactions, and thus promote sustainable crop production systems.
154

Geoprocessamento aplicado ? identifica??o, an?lise espacial e temporal de usos da terra em ?reas adjacentes ?s turfeiras da serra do espinha?o meridional / Geoprocessing applied to identification, spatial and temporal analysis of land use in peat bogs neighboring ?reas of the Southern Espinha?o

Fonseca, Samuel Ferreira da January 2016 (has links)
Submitted by M?rden L?les (marden.inacio@ufvjm.edu.br) on 2016-07-22T19:01:32Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Samuel_ Ferreira_ da_ Fonseca.pdf: 8804827 bytes, checksum: 34fb407113470f09d15f17a427597e1a (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2016-07-25T17:41:51Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Samuel_ Ferreira_ da_ Fonseca.pdf: 8804827 bytes, checksum: 34fb407113470f09d15f17a427597e1a (MD5) / Made available in DSpace on 2016-07-25T17:41:51Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Samuel_ Ferreira_ da_ Fonseca.pdf: 8804827 bytes, checksum: 34fb407113470f09d15f17a427597e1a (MD5) Previous issue date: 2016 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Turfeiras s?o produto da lenta decomposi??o de vegetais em ambientes saturados com ?gua. S?o ecossistemas particulares por acumularem grandes volumes de ?gua e mat?ria org?nica e atuam como registros cronol?gicos de mudan?as clim?ticas e ambientais. O objetivo deste trabalho foi: cartografar ?reas adjacentes ? turfeiras da Serra do Espinha?o Meridional ? SdEM cronologicamente (1964 ? 2014), para identificar e quantificar atividades antr?picas nos ?ltimos 50 anos, por meio de t?cnicas do geoprocessamento. Foram utilizadas fotografias a?reas de 1964 (1:60.000), e de 1979 (1:25.000). Tamb?m foram utilizadas imagens orbitais, dos sat?lites Landsat TM/5 dos anos 1984, 1995 e 2005, Landsat OLI/8 de 2014 e RapdEye de 2011. As cartas topogr?ficas do IBGE (1:100.000) formaram a base cartogr?fica. Todos os dados foram processados nas seguintes plataformas: Google earth? pro, ArcGIS? 9.3., ENVI? 4.5 e Quantum GIS? 2.10. O geoprocessamento ocorreu suportado pelas seguintes t?cnicas: georreferenciamento, mosaicagem, classifica??o supervisionada (MaxVer) e vetoriza??o. Os dados gerados foram utilizados para identifica??o dos tipos de atividades do uso da terra, como pastagem, eucalipto e outras culturas. A atividade agr?cola mais intensa nas ?reas adjacentes ?s turfeiras foi o cultivo de eucalipto, que n?o era cultivado em 1964, mas em 2014 ocupou 341,37 ha (2,07%). Outras culturas (milho, caf? e morango), que n?o eram cultivadas nas adjac?ncias das turfeiras em 1964, passaram a ocupar 312,46 ha (1,90%) em 2014. A ?rea ocupada com pastagens passou de 378,57 ha em 1964 para 1.176,40 ha em 2014, o que corresponde a um avan?o de 2,30 para 7,14% da ?rea adjacente total. As ?reas adjacentes ?s turfeiras n?o eram utilizadas de forma sistem?tica at? 1995. O avan?o das atividades antr?picas nas ?reas adjacentes ?s turfeiras nas ?ltimas d?cadas foi substancial. A decad?ncia da minera??o de diamante na regi?o de Diamantina coincide com a intensifica??o do uso da terra. Este cen?rio sinaliza a necessidade de cria??o de mecanismos legais para prote??o desses ecossistemas. Al?m disso, ? necess?rio estabelecer diretrizes para o planejamento da ocupa??o das ?reas no entorno das turfeiras da SdEM. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / ABSTRACT Peat bogs are outcome of slow plant decomposition in environments saturated by water. Theyare particular ecosystems that accumulate large amounts of water and organic matter and act as chronological records of climatic and environmental changes. This study aims to map peat bogs adjacent ?reas of the Southern Espinha?o - SdE chronologically (1964 - 2014), to identify and quantify anthropic activities over the past 50 years, through geoprocessing techniques. Aerial photographs from 1964 were used (1: 60,000) and 1979 (1: 25,000). Space-based images were also used Satellite Landsat TM/5 years 1984, 1995 and 2005, Landsat OLI/8 RapidEye 2014 and 2011. IBGE topographic maps (1:100,000) made up the cartographic base. All data were processed on platforms: Google earth ? pro, ArcGIS ? 9.3, 4.5 and ENVI ? Quantum GIS? 2.10. Geoprocessing was supported by these techniques: georeferencing, mosaicing, supervised classification (MaxVer) and vectorization. Data generated were used to identify types of land use activities such as grazing, eucalyptus and other crops. The most intense agricultural activity in adjacent ?reas to peat bogs was eucalyptus cultivation, which was not cultivated in 1964, but in 2014, it held 341.37 ha (2.07%). Other crops (corn, coffee and strawberry), which were not cultivated in peat lands vicinity in 1964, came to occupy 312.46 ha (1.90%) in 2014. The ?rea occupied by pastures increased from 378.57 ha in 1964 to 1176.40 ha in 2014, which corresponds to an advance of 2.30 to 7.14% of the total adjacent ?rea. Adjacent ?reas to peat bogs were not used systematically until 1995. Human activities advance in adjacent ?reas to peat bogs in recent decades has been extensive. Diamond mining decay in Diamantina region coincides with the intensification of land use. This scenario shows the necessity to establish legal mechanisms to protect these ecosystems. Moreover, it is necessary to establish guidelines for planning o ?reas occupation surrounding the Southern Espinha?o peat bogs.
155

Assessment of nutrient emission factors for different manure and digestate management systems

Ryding, Caroline January 2018 (has links)
An efficient management of organic fertilizers (here animal manure and digestate) is of large concern in today´s agriculture. When evaluating the efficiency of alternative management systems, differences in nutrient losses (emissions) must be taken into consideration. Those can be rather specific for e.g. a geographical region and agricultural system. This literature study aimed at identifying emission factors and uncertainty ranges, that are relevant to use in comparative system studies of different organic fertilizer management systems in South Swedish climate. Emissions from manure and digestate storage, application and field losses were considered. For carbon, the sequestration of organic carbon in the soil was considered instead of the carbon dioxide emissions from manure/digestate decomposition in soils. The values were very variable, and the median value was used as the selected emission factor. From storage of liquid cow manure, the ammonia emission for storage with cover was 3 % of the ammonium content, and 10 % without cover. It was about the same for both liquid pig manure (8 %) and solid cattle manure (10 %). The methane emissions during storage were 10 % of the maximum methane potential. Ammonia emissions during application ranged from 10-20 % of ammonium-nitrogen. Two studies of manure carbon sequestration were found that was applicable for the Swedish climate. They indicated that about 8-11 % of the carbon applied as solid manure was sequestered, compared to about 4 % for liquid manure.
156

Impact of land-use change for lignocellulosic biomass crop production on soil organic carbon stocks in Britain

McClean, Gary James January 2016 (has links)
The contribution of energy from biomass sources is projected to increase in Britain to assist in meeting renewable energy targets and reducing anthropogenic CO2 emissions. With increasing concerns over the sustainability of food crop-based biofuels, purpose-grown lignocellulosic biomass crops such as Miscanthus and short rotation coppice (SRC) willow have been promoted as more sustainable feedstocks for the production of heat and electricity as well as for the future production of liquid biofuels. With the introduction of the Energy Crops Scheme, land-use change (LUC) for lignocellulosic biomass crop production has become increasingly common in Britain in recent decades. However, there is limited understanding of the impact this has on soil organic carbon (SOC) stocks and limited predictability concerning the overall trajectory, magnitude and rate of SOC changes under a range of different conditions. Using a chronosequence of 93 biomass crop plantations in England and Wales, mainly of 1 to 14 years age, empirical models were developed to determine the short term trajectory of SOC stocks following LUC from arable and grassland to SRC willow and Miscanthus production. SOC stocks were calculated for each site using a fixed sampling depth of 30 cm and estimated changes were inferred by comparing with typical pre-change SOC stocks. These results indicate that only LUC from arable crops to SRC willow demonstrated an overall increase in SOC stocks, by an estimated 15.3 ± 2.2 t C ha-1 (± 95% confidence intervals) after 14 years and 68.8 ± 49.4 t C ha-1 after 22 years. LUC from arable crops to Miscanthus and from both arable crops and grassland to SRC willow and Miscanthus demonstrated no overall net effect on SOC stocks. Soil texture and climate data were measured for each site and multivariable models were created to assess the influence of different environmental conditions on SOC trajectory. In most cases the addition of these explanatory variables improved the model fit, and the models provide some preliminary estimates of more region-specific changes in SOC following LUC. Since LUC to biomass crops often causes a loss of SOC, at least in the short term, the potential for pyrogenic carbon (PyC) to ameliorate this effect was investigated. Studies indicate that PyC can interact with and stabilise native SOC, a process termed negative priming, although the potential for PyC to reduce LUC-induced losses of SOC by negative priming has not yet been assessed. Although negative priming has been observed in many studies, most of these are long term incubation experiments which do not account for the impact of environmental weathering of PyC on interactions with native SOC. Here the aim was to assess the impact of environmentally weathered PyC on native SOC mineralisation at different points in LUC from arable crops to SRC willow. Soil was sampled to a 5 cm depth from multiple recently established SRC willow plantations approximately 2 years after amendment with PyC. Cumulative CO2 flux was measured weekly from incubated soil and soil-surface CO2 flux was also measured in the field. The results demonstrate a PyC-induced increase in CO2 flux for the surface 5 cm of soil. However, no net effect on soil-surface CO2 flux was observed in the field. Although the mechanisms for these contrasting effects remain unclear, they do not suggest that PyC can reduce LUC-induced SOC losses through negative priming.
157

Introducing a terrestrial carbon pool in desert bedrock mountains

January 2013 (has links)
abstract: Growth of the Phoenix metropolitan area led to exposures of the internal bedrock structure of surrounding semi-arid mountain ranges as housing platforms or road cuts. Such exposures in the Sonoran and Mojave deserts reveal the presence of sedimentary calcium carbonate infilling the pre-existing fracture matrix of the bedrock. Field surveys of bedrock fractures filled with carbonate (BFFC) reveal an average of 0.079 +/- 0.024 mT C/m2 stored in the upper 2 m of analyzed bedrock exposures. Back-scattered electron microscopy images indicate the presence of carbonate at the micron scale, not included in this estimation. Analysis of the spatial extent of bedrock landforms in arid and semi-arid regions worldwide suggests that ~1485 GtC could potentially be stored in the upper 2 m horizon of BFFCs. Radiocarbon dating obtained at one of the sites indicates it is likely that some of the carbonate was flushed into the bedrock system during glacial wet pulses, and is stored on Pleistocene timescales or longer. Strontium isotope analysis at the same site suggest the potential for a substantial cation contribution from weathering of the local bedrock, indicating the potential exists for sequestration of atmospheric carbon in BFFCs. Rates of carbon release from BFFCs are tied to rates of erosion of bedrock ranges in desert climates. / Dissertation/Thesis / M.A. Geography 2013
158

Effect of land use on soil fertility and carbon sequestration

Maharjan, Menuka 20 March 2018 (has links)
No description available.
159

A cana-de-açucar e as mudanças climaticas : efeitos de uma atmosfera enriquecida em 'CO IND. 2' sobre o crescimento, desenvolvimento e metabolismo de carboidratos de Saccharum ssp / Sugarcane and climate changes : effects of 'CO IND. 2 enrichment atmosphere in growth, development and carbohydrate metabolism in Saccharum ss

Souza, Amanda Pereira de 20 April 2007 (has links)
Orientadores: Marcos Silveira Buckeridge, Marilia Gaspar / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-09T03:07:16Z (GMT). No. of bitstreams: 1 Souza_AmandaPereirade_M.pdf: 752519 bytes, checksum: 0abdf68fd1d19b70a0af931741ccf052 (MD5) Previous issue date: 2007 / Resumo: Desde o início da Revolução Industrial as concentrações de CO2 atmosférico aumentaram em cerca de 30% e estimativas apontam que esta concentração poderá atingir aproximadamente 720 ppm até a metade deste século. Estudos sobre o efeito do alto CO2 no desenvolvimento de diversas espécies vegetais já foram realizados, porém poucos com espécies de gramíneas tropicais do tipo C4, como é o caso da cana-de-açúcar. Considerando a importância econômica da cana e seu potencial na obtenção de biocombustíveis é importante saber como esta cultura irá responder ao aumento previsto na concentração de CO2 atmosférico. Sendo assim, o objetivo deste trabalho foi estudar o efeito do aumento do CO2 atmosférico sobre o crescimento, desenvolvimento e metabolismo de carboidratos da cana-de-açúcar visando avaliar o potencial de seqüestro de carbono e o impacto das mudanças climáticas sobre a produtividade. Parâmetros fisiológicos, bioquímicos e moleculares foram analisados em plantas cultivadas em câmaras de topo aberto durante 50 semanas com atmosfera de CO2 ambiente (~370 ppm) e elevada (~720 ppm). Os principais resultados obtidos indicam incremento em altura, na taxa fotossintética e em biomassa de colmo e folhas das plantas cultivadas sob elevado CO2. Ao final das 50 semanas foi detectado no colmo das plantas crescidas em tais condições, um aumento no teor de sacarose, de fibras e no conteúdo de celulose. A análise do perfil de transcritos de folhas após 9 e 22 semanas de cultivo usando microarranjos revelou expressão diferencial de 37 genes, sendo que 14 foram reprimidos e 23 foram induzidos e correspondem principalmente a genes de fotossíntese e desenvolvimento. Nossos resultados indicam que a cultura da cana-de-açúcar tem capacidade para seqüestro de carbono e potencial para aumento na produtividade em condições de alta concentração de CO2 / Abstract: Since the beginning of the Industrial Revolution, the concentrations of CO2 in the atmosphere increased about 30% and the current forecasts point out that this concentration will reach approximately 720 ppm until the middle of this century. Studies about the effect of CO2 on the development of several plant species have been performed. However, few studies have been performed with tropical grass species having photosynthesis C4, as is the case of sugar cane. Due to the economic importance of sugar cane and its high potential to obtain biofuel, it is important to known how this crop will respond to the forecasted increase in the CO2 concentration in the atmosphere. Therefore, the goal of this work was to study the effects of increased CO2 concentration on growth, development and carbohydrate metabolism of sugar cane aiming the evaluation of the potential of this specie for carbon sequestration and the impact of the global climatic change on its productivity. Physiological, biochemical and molecular features of these plants have been analyzed during 50 weeks of growth in Open-Top-Chambers (OTCs) with ambient (~370 ppm) and elevated (~720 ppm) CO2 concentrations. After 50 weeks of growth under these conditions, we observed an increase of sucrose content, fiber an also in cellulose contents in stems of plants grown under elevated CO2. The microarray analysis of the transcriptome of leaves was obtained after 9 and 22 weeks and revealed differential expression of 37 genes. Fourteen genes were repressed and 23 induced by elevated CO2. The latter correspond mainly to the processes of photosynthesis and development. Our results indicate that the sugar cane crop has a high potential for carbon sequestration and increase of productivity under elevated CO2 concentrations / Mestrado / Biologia Celular / Mestre em Biologia Celular e Estrutural
160

O seqüestro de carbono e as substâncias húmicas na área de influência da BR-163 - Cuiabá-Santarém / Carbon sequestration and humic substances in BR-163 influences area - Cuiabá-Santarém

Orlando Paulino da Silva 26 September 2008 (has links)
Compreender os ciclos de nutrientes e a dinâmica da matéria orgânica no ecossistema da Amazônia é essencial para o domínio do manejo eficiente da floresta e do solo. O desaparecimento de florestas tropicais, acompanhada de acelerados processos de perda de solo e de matéria orgânica, pelo desmatamento, queimadas e avanço da fronteira agrícola despertam preocupações. As características das substâncias húmicas remetem aos processos de gênese da matéria orgânica, à capacidade de sustentabilidade para os usos múltiplos em cultivos e aparece como indicador da qualidade do solo. O objetivo deste trabalho foi relacionar as características das substâncias húmicas do solo com o seqüestro de carbono em sítios de floresta em clímax, em área moderadamente e intensamente antropizada, ambientes de influência da Rodovia BR-163 - Cuiabá-Santarém, região que experimenta um incremento das ações antrópicas em função do anúncio da pavimentação desta rodovia. Foram determinadas as características das substâncias húmicas pelas técnicas de espectroscopia no infravermelho com transformada de Fourier (FTIR), análise elementar, espectroscopia de fluorescência de luz no UV/Visível, espectroscopia de absorção de luz no UV/Visível, espectroscopia de ressonância magnética nuclear (RMN) e espectroscopia de ressonância paramagnética eletrônica nuclear (EPR). Os resultados de infravermelho das substâncias húmicas do solo do sítio de floresta em clímax, indicam alta complexidade no arranjo conformacional, denotando-se a presença de elevada humificação do material orgânico, o que é corroborado pelos resultados de fluorescência, onde as características das substâncias húmicas deste ambiente apresentaram maior policondensação e grau de humificação. Utilizando-se a espectroscopia de absorção de luz no UV/Visível, constatou-se que a razão E4/E6 é de 2,27 para solo do ambiente de floresta em clímax. Esse é o menor valor das três frações, o que demonstra que as substâncias húmicas deste sítio estão em estágio elevado de policondensação e apresentam maior quantidade de estruturas aromáticas. Os resultados de RMN indicam que a maior percentagem de carbono aromático está exatamente nas substâncias húmicas do solo do sítio de floresta em clímax. Os resultados de EPR demonstram também que as substâncias húmicas dos solos dos sítios em clímax apresentam maiores números de radicais livres do tipo semiquinona (7,52) dos três ambientes estudados. As substâncias húmicas provenientes dos solos dos sítios com intensa atividade antrópica indicam a presença de menor grau de humificação, pelo número de radicais livres do tipo semiquinona (4,68), menor valor dos três ambientes estudados. Desta forma, as características das substâncias húmicas do solo de ambientes em clímax, pela elevada aromaticidade, policondensação e grau de humificação, proporcionam aumento da biodiversidade, incremento da produtividade, melhoria da estrutura deste solo, contribuindo junto à formação de fração húmica não lábil, bem como maior estabilidade dos complexos organominerais, condições favoráveis para o seqüestro de carbono e mitigação do aumento do efeito estufa. / Understanding the cycles of nutrients and organic matter dynamics in Amazons ecosystem is essential for the domain of efficient management of the forest and soil. The disappearance of tropical forests, accompanied by processes of accelerated loss of soil and organic matter, for the deforestation, forest fires and advancement of agricultural frontier arouse concerns. The characteristics of humic substances refer processes of genesis organic matter, capacity of sustainability for multiple uses in cultures appears as indicator the quality of the organic matter. The objective of this work was to relate the characteristics of humics substances in the soil, with the carbon sequestration in sites of forest in climax, in moderately and intensely area in humans use, environments in Influence of highway BR-163 - Cuiaba-Santarem, a region experiencing an increase in action of the human being according to the announcement of paving the road. There were certain characteristics of humic substances by the Fourier transform infrared (FTIR) spectroscopy, elemental analysis, ultraviolet-visible fluorescence spectroscopy, ultraviolet-visible absorption spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and electronic paramagnetic resonance (EPR) spectroscopy. The results of infrared of humic substances in soil site of a climax forest, show high complexity in conformal arrangement, showing up the presence of high humification of organic material, which is corroborated by the results of fluorescence, where the characteristics of humic substances this environment polycondensation and had greater degree of humification. Using ultraviolet-visible absorption spectroscopy, it was found that the reason E4/E6 is 2.27 for the environment of forest in climax. This is the lowest of the three fractions, which shows that the humic substances from this site are in high stage of polycondensation and the greatest amount of aromatic structures. The results of NMR indicate that the highest percentage of carbon aromatic is exactly humic substances in soil from site of forest in climax. The results of EPR also demonstrate that the soil humic substances in climax\'s sites show the highest numbers of free radicals semiquinonas type (7.52) in the three kinds of environments studied. The humic substances from the soil of sites with intense human activity indicate the lesser presence of degree humification, for the number of free radicals semiquinona\'s type (4.68), lower value of the three environments studied. Thus, the characteristics of humic substances in soil from environments in the climax for the high aromaticity, polycondensation and degree of humification, provide an increase of biodiversity, increasing productivity, improving the structure of the soil, contributing next to the formation of humic fraction not labile, greater stability of organic minerals complexes, favourable conditions for carbon sequestration and mitigation of increased greenhouse effect.

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