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All publications of “Alexandre Christófaro Silva”

21 results

Chemical-Mineralogical Characterization of Magnetic Materials from Magnetic Soils of the Southern Espinhaço Mountain Chain and of the Upper Jequitinhonha Valley, State of Minas Gerais, Brazil

Alexandre Christófaro Silva, Solange de Souza, José Domingos Fabris, Maurício Soares Barbosa, Uidemar Morais Barral, Roberto Vial Costa

09/Mar/2017

ABSTRACT In the Southern Espinhaço Mountain Chain and in the Upper Jequitinhonha Valley, magnetic soils, in different pedogenetic stages, are found to be forming over intrusions of basic lithology. The essential chemical and mineralogical properties of samples from magnetic soil profiles from those two physiographic environments in the state of Minas Gerais, Brazil, are reported. Three of the pedons (Rhodic Kandiustox – RKox, Rhodic Haplustox – RHox, and Typic Argiustoll – TAoll) were identified as being indeed developed over basic […]

CHARACTERIZATION OF HEADWATERS PEATS OF THE RIO ARAÇUAÍ, MINAS GERAIS STATE, BRAZIL

Diêgo Faustolo Alves Bispo, Alexandre Christofaro Silva, Cristiano Christofaro, Max Leandro Naves Silva, Maurício Soares Barbosa, Bárbara Pereira Christofaro Silva, [...]

01/Mar/2015

Peatlands are soil environments that accumulate water and organic carbon and function as records of paleo-environmental changes. The variability in the composition of organic matter is reflected in their morphological, physical, and chemical properties. The aim of this study was to characterize these properties in peatlands from the headwaters of the Rio Araçuaí (Araçuaí River) in different stages of preservation. Two cores from peatlands with different vegetation types (moist grassland and semideciduous seasonal forest) from the Rio Preto [Preto River] […]

Surface mapping, organic matter and water stocks in peatlands of the Serra do Espinhaço meridional – Brazil

Márcio Luiz da Silva, Alexandre Christófaro Silva, Bárbara Pereira Christófaro Silva, Uidemar Morais Barral, Pablo Gomes e Souza Soares, Pablo Vidal-Torrado

01/Oct/2013

Peatlands are soil environments that store carbon and large amounts of water, due to their composition (90 % water), low hydraulic conductivity and a sponge-like behavior. It is estimated that peat bogs cover approximately 4.2 % of the Earth’s surface and stock 28.4 % of the soil carbon of the planet. Approximately 612 000 ha of peatlands have been mapped in Brazil, but the peat bogs in the Serra do Espinhaço Meridional (SdEM) were not included. The objective of this […]

Lignocellulosic and isotopic composition of vegetation and soil organic matter of a tropical peat. I floristic composition, biomass and carbon stock

Vinicius Evangelista Silva, Alexandre Christofaro Silva, Rosana Cristina Pereira, Plínio Barbosa de Camargo, Bárbara Pereira Christofaro Silva, Uidemar Morais Barral, [...]

01/Feb/2013

Soil organic matter (SOM) is one of the major reservoirs of carbon on Earth and is one of the key contributors to the carbon cycle. Peatlands are natural accumulators of organic matter commonly derived from decomposing plant residues in water-saturated environments, and represent an initial stage of a much longer pedogenic pathway leading to carbonification. The soil biomass markedly influences the global carbon cycle, accounting for approximately 85 % of all carbon on the Earth’s surface. Plant tissues are mainly […]

Lignocellulosic and isotopic composition of vegetation and soil organic matter of a tropical peat. II humic substances and humification processes

Alexandre Christofaro Silva, Vinicius Evangelista Silva, Bárbara Pereira Christofaro Silva, Plínio Barbosa de Camargo, Rosana Cristina Pereira, Uidemar Morais Barral, [...]

01/Feb/2013

Much of the organic matter of a typical peat consists of humic substances, mainly formed via humification of organic residues, decomposed by soil microorganisms, and by the polymerization of organic compounds to functional macromolecules, which are normally more resistant to degradation. The fundamental pathways governing the humification of soil organic matter (SOM) are not well understood so far, and most available data about the identified chemical precursors of humic substances and the main chemical routes by which they are transformed […]

Soil organic carbon profiles in the South and Southern Espinhaço Mountain Regions, Minas Gerais: modelling of deeper layers

Yuri Lopes Zinn, Adriano Ribeiro Guerra, Alexandre Christofaro Silva, João José Marques, Geraldo César de Oliveira, Nilton Curi

01/Nov/2012

Despite the interest in the spatial variability of key soil properties, depth-related variations have only recently received more attention in the literature. Of all soil properties, soil organic carbon (SOC) is perhaps the most depth-related and difficult to understand. Soil data from two regions in the State of Minas Gerais, Brazil, were used to model SOC profiles and identify factors of influence. In both the South and Southern Espinhaço regions, SOC profiles were best described by log functions. Oxisols had […]

Mapping, organic matter mass and water volume of a peatland in serra do espinhaço meridional

José Ricardo da Rocha Campos, Alexandre Christófaro Silva, Pablo Vidal-Torrado

01/Jun/2012

Peatlands form in areas where net primary of organic matter production exceeds losses due to the decomposition, leaching or disturbance. Due to their chemical and physical characteristics, bogs can influence water dynamics because they can store large volumes of water in the rainy season and gradually release this water during the other months of the year. In Diamantina, Minas Gerais, Brazil, a peatland in the environmental protection area of Pau-de-Fruta ensures the water supply of 40,000 inhabitants. The hypothesis of […]

Microbial and soil properties in restoration areas in the jequitinhonha valley, Minas Gerais

Danielle Cristina Fonseca Santos, Paulo Henrique Grazziotti, Alexandre Christófaro Silva, Aldo Vilar Trindade, Enilson de Barros Silva, Lidiomar Soares da Costa, [...]

01/Dec/2011

To mitigate the impacts of eucalypt monoculture, forestry companies in the Upper Jequitinhonha Valley (MG) have adopted the insertion of strips of native vegetation in-between the commercial plantations. The method used for the creation of these corridors is to allow spontaneous regrowth of native vegetation in areas previously under eucalypt. The objective of this study was to evaluate the effect of cover crops on microbial and soil properties for a detailed description of the restoration process of native vegetation in […]

Root growth of tomato seedlings intensified by humic substances from peat bogs

Alexandre Christofaro Silva, Luciano Pasqualoto Canellas, Fábio Lopes Olivares, Leonardo Barros Dobbss, Natalia Oliveira Aguiar, Daniele Ângela Rossinol Frade, [...]

01/Oct/2011

Peats are an important reserve of humified carbon in terrestrial ecosystems. The interest in the use of humic substances as plant growth promoters is continuously increasing. The objective of this study was to evaluate the bioactivity of alkaline soluble humic substances (HS), humic (HA) and fulvic acids (FA) isolated from peats with different decomposition stages of organic matter (sapric, fibric and hemic) in the Serra do Espinhaço Meridional, state of Minas Gerais. Dose-response curves were established for the number of […]

Highlands of the upper Jequitinhonha valley, Brazil. I – characterization and classification

Fábio Henrique Alves Bispo, Alexandre Christofaro Silva, Pablo Vidal Torrado

01/Aug/2011

In the upper Jequitinhonha valley, state of Minas Gerais, Brazi, there are large plane areas known as “chapadas”, which are separated by areas dissected by tributaries of the Jequitinhonha and Araçuaí rivers. These dissected areas have a surface drainage system with tree, shrub, and grass vegetation, more commonly known as “veredas”, i.e., palm swamps. The main purpose of this study was to characterize soil physical, chemical and morphological properties of a representative toposequence in the watershed of the Vereda Lagoa […]

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