Estudo da matéria orgânica e composição elementar de solos arenosos de regiões próximas a São Gabriel da Cachoeira no Amazonas

Santos, Cléber Hilario dos

doi:10.11606/t.75.2014.tde-04072014-105024

Cited by 3 publications

(5 citation statements)

References 137 publications

(232 reference statements)

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“…The results obtained in this study were in agreement with the findings of Ishida [25] and Santos [22] for a Latosol-Spodosol system in the Amazon region. It was reported that there was accumulation of Al and Fe in the Bh horizons, with the highest value obtained for Al.…”

Section: Samples Carbon (%) Concentration Of Metals (G/kg) Metals Aresupporting

confidence: 92%

Evaluation of the roles of metals and humic fractions in the podzolization of soils from the Amazon region using two analytical spectroscopy techniques

Tadini

Nicolodelli

Marangoni

et al. 2019

Microchemical Journal

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Soil organic matter (SOM) plays an important role in environmental sustainability, since it is involved in carbon and nutrient cycling. Consequently, it is a key factor to consider in studies concerning global climate change and agronomy.Among the main components of SOM are humic substances (HS), which are divided, according to their solubility, into humic acid (HA), fulvic acid (FA), and humin (HU) fractions. Study of the chemical properties of this organic matter is important for understanding the biogeochemical processes occurring in the soil. The aim of this work was to determine the metals iron (Fe) and aluminum (Al), using flame atomic absorption spectrometry (FAAS) and laser-induced breakdown spectroscopy (LIBS), in order to elucidate the role of organic matter in the transport of these metals in Amazonian soils. The results showed that FA was important for Al, while the HA fraction was more selective towards Fe. The translocations of these metals to deeper profiles in two different soils involved either young and less humified organic matter, or older organic matter with a low degree of humification. Therefore, these two humic fractions were involved in the process of soil podzolization, with FA having a predominant role in the transport of Al, while HA was mainly responsible for the transport of Fe.

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Section: Samples Carbon (%) Concentration Of Metals (G/kg) Metals Aresupporting

confidence: 92%

Evaluation of the roles of metals and humic fractions in the podzolization of soils from the Amazon region using two analytical spectroscopy techniques

Tadini

Nicolodelli

Marangoni

et al. 2019

Microchemical Journal

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“…The trees on the Hill of Six Lakes have a canopy height of about 8–10 m and have relatively small diameters compared with 20–30 m individuals at the foot of the hill. The thin (almost non‐existent) soils are unlikely to offer any buffering against drought, and contrast with the typical Latosol clays at the foot of the hill (Santos, ). The sum of edaphically controlled vegetation (local) compared with the sum of non‐edaphically controlled vegetation (regional) in our record, shows that the contribution of regional taxa was more or less the same over time (Figure , SI5), indicating that both the trees of the hill and of the lowland forest were resilient to the MHDE drought.…”

Section: Discussionmentioning

confidence: 99%

Vegetation response to climatic changes in western Amazonia over the last 7,600 years

Nascimento

Martins

Cordeiro

et al. 2019

Journal of Biogeography

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Aim Ongoing and future anthropogenic climate change poses one of the greatest threats to biodiversity, affecting species distributions and ecological interactions. In the Amazon, climatic changes are expected to induce warming, disrupt precipitation patterns and of particular concern, to increase the intensity and frequency of droughts. Yet the response of ecosystems to intense warm, dry events is not well understood. In the Andes the mid‐Holocene dry event (MHDE), c. 9,000 to 4,000 years ago, was the warmest and driest period of the last 100,000 years which coincided with changes in evaporation and precipitation that caused lake levels to drop over most of tropical South America. This event probably approximates our near‐climatic future, and a critical question is: How much did vegetation change in response to this forcing? Location Lake Pata, Brazilian Western Amazonia. Taxon Terrestrial and aquatic plants. Methods We used pollen, charcoal, total organic carbon (TOC), total nitrogen (TN), δ13C and δ15N data from a new high‐resolution core that spans the last c. 7,600 years history of Lake Pata. Results We found that in the wettest section of Amazonia changes associated with the MHDE were detected in the geochemistry analysis but that vegetation changed very little in response to drought during the Holocene. This is the first high‐resolution core without apparent hiatuses that spans most of the Holocene (last 7,600 cal yr bp) from Lake Pata, Brazil. Changes in the organic geochemistry of sediments indicated that between c. 6,500 and 3,600 cal yr bp lake levels dropped. Vegetation, however, showed little change as near‐modern forests were seen throughout the record, evidencing the substantial resilience of this system. Only a few species replacements and minor fluctuations in abundance were observed in the pollen record. Main conclusions The mid‐Holocene warming and reduced precipitation had a limited impact on western Amazonian forests. We attribute much of the resilience to a lack of fire in this system, and that if human‐set fires were to be introduced, the forest destruction from that cause would override that induced by climate alone.

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“…As medidas foram realizadas em triplicata para as amostras pastilhadas presente na amostra de solo inteiro (Milori et al, 2004(Milori et al, , 2006SANTOS, 2014), ou seja:…”

Section: Fluorescence (Lif)unclassified

“…As soluções contendo AH em tampão na presença ou não de OTC, após o período de agitação, foram analisadas de modo a investigar as diferenças proporcionadas pelas interações AH-OTC nas amostras estudadas. Para tal, utilizou-se um espectrômetro modelo LS50B PERKIN ELMER, com largura de fenda para todos os monocromadores de 10 nm e velocidade de varredura de 120 nm min -1 (SWIFT, 1996;SANTOS, 2014).…”

Section: Espectroscopia De Fluorescência Na Região Do Uv-visunclassified

“…Os espectros de fluorescência das substâncias húmicas são constituídos pela soma dos espectros dos diferentes tipos de fluoróforos, consequência da complexidade molecular e da heterogeneidade dessas substâncias (NARIMOTO, 2006). Assim, os espectros apresentam bandas que são avaliadas de acordo com suas intensidades e deslocamento para maiores ou menores comprimentos de onda (SANTOS, 2014). A intensidade da fluorescência também é afetada pelo pH do meio, além da presença de eletrólitos e outras estruturas orgânicas (STEVENSON, 1994).…”

Section: Espectroscopia De Fluorescência Na Região Do Uv/vísunclassified

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Oxitetraciclina como antibiótico promotor de crescimento: comportamento com substâncias húmicas e no solo empregando-se métodos espectroscópicos e LC-MS

Martelli¹

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, pela orientação, confiança na realização deste trabalho e aprendizado ao longo de todos esses anos; À minha família...meu irmão, meus avós e meus pais; meus grandes exemplos, por todo o incentivo; Ao Fabricio, por ser meu companheiro de todas as horas, por dividir comigo seus dias, suas conquistas e anseios, e seus sonhos e planos; À minha Helena, tão pequenina e tão grandiosa, pela sua chegada em minha vida; por ter me dividido entre o acadêmico e a maternidade...você é razão de alegria e minha inspiração para apreciar mais os pequenos detalhes do caminho, para ser forte, para sonhar, para acreditar em ser melhor a cada dia que passa. Agradeço por muitas vezes, mais nos ensinar que aprender; Aos amigos e colegas que fiz na Embrapa nestes anos, o meu "muito obrigada" pelo convívio e pelos aprendizados, eu seria até injusta ao tentar listá-los, em meio a tantos nomes Aos funcionários da Embrapa Instrumentação, pela prontidão e boa vontade em ajudar, por todo o suporte e auxílio prestado, em especial àqueles que levarei principalmente como exemplos, entre os quais: Joana,

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Estudo da matéria orgânica e composição elementar de solos arenosos de regiões próximas a São Gabriel da Cachoeira no Amazonas

Cited by 3 publications

References 137 publications

Evaluation of the roles of metals and humic fractions in the podzolization of soils from the Amazon region using two analytical spectroscopy techniques

Evaluation of the roles of metals and humic fractions in the podzolization of soils from the Amazon region using two analytical spectroscopy techniques

Vegetation response to climatic changes in western Amazonia over the last 7,600 years

Oxitetraciclina como antibiótico promotor de crescimento: comportamento com substâncias húmicas e no solo empregando-se métodos espectroscópicos e LC-MS

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