Navegando por Assunto "Solos"

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Acesso aberto (Open Access)
Adequação de método para avaliação de risco de contaminação ambiental em áreas de estocagem de combustíveis
(Universidade Federal do Pará, 2002-02-28) CHAVES, Cláudio Cezar Cunha de Vasconcelos; CORRÊA, José Augusto Martins; http://lattes.cnpq.br/6527800269860568
Acesso aberto (Open Access)
Aplicação da RUSLE a uma pequena bacia hidrográfica da Amazônia
(Universidade Federal do Pará, 2013-09-26) SANTOS, Diego Benvindo Oliveira; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808
The Amazon is experiencing severe changes due to anthropogenic activities, among which the transformation of forested land into areas for agricultural use stand out, intensifying erosion processes. Erosion, especially the drag of particles by runoff, causes a reduction of soil fertility impairing agricultural productivity and impacting the quality and quantity of surface water resources, a fact compounded by strong rainfall and naturally poor soils in the region. In this context, knowledge of erosion processes, such as through the use of mathematical models for predicting soil loss helps in determining management practices for sustainable use of natural resources. This study aimed to evaluate the applicability of the empirical model RUSLE (Revised Universal Soil Loss Equation) in the region, which considers the interaction between the rain energy, soil and topography characteristics, as well as the uses and management practiced. This research applied the RUSLE in the upper basin of the Igarapé da Prata stream, with an approximate area of 37 km², located in the municipality of Capitão Poço, Pará, Brazil, approximately 160 km from the capital Belém, in Pará Northeast region. This research also consisted in the construction of a geo-referenced database made from public sources; such data passed through adaptations for insertion into the environment of the ArcGIS to quantify the parameters of RUSLE, which when combined allowed the generation of a map of soil loss for the study area. The small upper basin of Igarapé da Prata presented soil loss values ranging between 0.004 and 72.48 t/ha year, with an average value of 5.12 and a standard deviation of 6.97, where approximately 12% of its total area presents environmental risks due to erosive processes.
Acesso aberto (Open Access)
Aplicação de dados multisensor (SAR e ETM+) no reconhecimento de padrões de uso e ocupação do solo em costas tropicais: Costa Amazônica, Amapá, Brasil
(2009) SANTOS, Valdenira Ferreira dos; POLIDORI, Laurent; SILVEIRA, Odete Fátima Machado da; FIGUEIREDO JÚNIOR, Alberto Garcia de
Environmental studies require information on land use and land cover. This paper presents the applicability of multi-sensor satellite data (optical and radar) for land use and land cover on the Amapá coastal plain for mapping and recognition of natural and anthropogenic dynamics. This area is influenced by the Amazon River, by tides (tidal bore) and by the Intertropical Convergence Zone (ITCZ). Anthropogenic processes are associated with water buffalo ranching. The environmental information was acquired from previous data and field observation and was correlated with remote sensing data (JERS-1, RADARSAT-1, image from ETM+ sensor from Landsat 7 and DEM SRTM), digitally processed for multi-sensor, multi-scale and multi-date approach. Eight patterns of land use and land cover were identified (mangrove, "várzea" forest, arbustive vegetation area, freshwater marsh, anthropic field, intertidal plain, estuarine channel and lakes) as well with indication of natural and anthropogenic geomorphic features. The results from the evaluation of remote sensing data and the techniques applied demonstrated the potential of the remote sensing tool for studying environments in highly dynamic tropical coastal areas of difficult access. However, these tools may present some limitations once applied to application to the Amazon coast, which is a region under strong dynamic natural and anthropogenic processes.
Acesso aberto (Open Access)
Atributos químicos do solo e composição química de folhas de mangue vermelho (Rhizophora mangle L.) em um manguezal e área transicional em São João de Pirabas, Pará
(Universidade Federal do Pará, 2015) NASCIMENTO, Bruno Delano Chaves do; RUIVO, Maria de Lourdes Pinheiro; http://lattes.cnpq.br/9419564604488031
Mangroves are characteristic coastal ecosystems of tropical and subtropical regions of great social and ecological importance. At Amazon these ecosystems represent more than half of mangrove areas of Brazil (about 70%) and are renowned for their great exuberance and magnitude related to regular distribution of rainfall, high temperatures, the large tidal range (> 4m) and the supply of sediments from the rivers of this region. Changes in water characteristics and physic-chemical soil properties can cause changes in nutrient dynamics in these ecosystems. In transitional environments these characteristics are altered and may have effects on the concentration of nutrients in the ecosystem compartments. In order to differentiate these transitional environments and the actual mangrove environments for the concentration of nutrients, this study aims to determine the nutrient content in the soil, in Rhizophora mangle L. leaves and leaf litter in these two types of environments in two seasonal periods, in a mangrove of the Amazon coast. Samples were collected in the drier month (September 2011) and in the rainy month (April 2012) in the two areas and subjected to chemical analysis for the concentration of macro (Ca, Mg, Na, K, Al, S, P, N, C) and micro nutrients (Cu, Zn, Mn, Fe). We also analyzed the physico-chemical properties of the soil (Eh, pH and salinity) and the granulometry of the ground. The results show higher nutrient concentrations in the fringe mangrove soil when compared to the transition zone (mangrove x secondary forest), indicating that the Eh, which is lower in the first influenced by the proximity to the sea and the highest frequency of flooding by tides, is the main differentiating factor in the concentration of soil nutrients. The nutrients in the Rhizophora mangle L. leaves not differ significantly from one environment to another and do not follow the same pattern of soil concentration on the two areas studied, however, the leaves nutrients are more influenced by the difference of a climatic period for other. Thus, the red mangrove trees of the transition zone can maintain a concentration of nutrients similar to the fringe of the forest, and the structural difference of the woods is more related to soil particle size than the nutritional relationship, since these trees have physiological mechanisms for the maintenance and selection of nutrients, such as N which could be a limiting nutrient in these environments.
Acesso aberto (Open Access)
Atributos químicos do solo e interação com folhas de serapilheira em manguezais da ilha de Itarana e comunidade Caranã, São João de Pirabas, Pará, Brasil
(Universidade Federal do Pará, 2013-04-26) SOUZA, Marina Lopes de; MOTA, Maria Aurora Santos da; http://lattes.cnpq.br/5817549281617240; RUIVO, Maria de Lourdes Pinheiro; http://lattes.cnpq.br/9419564604488031
Mangroves are coastal ecosystems situated in the land-sea interface, under constant influence of the dynamics of the tides. It is known that this ecosystem is considered one of the most productive in the world, due to the large amount of organic matter that is produced and fed into other environments. This productivity, in turn, has its origin both in litterfall produced within the system itself, the inputs of nutrients arising tidal and storm water. The nutrient dynamics in mangroves is linked to factors such as the frequency of flooding by tides, the seasonal period, the topography and biogeochemical processes. In this context, this study aims to evaluate the soil chemical properties and verify the interaction between soil and leaf litterfall in mangroves in northeast Pará, in the rainy and less rainy season. For this, samples of soil and leaf litterfall were collected in different seasonal periods, for analyses of pH, Eh, interstitial salinity, C, N, S, P, Fe, Na +, K +, Ca + 2, Mg + 2 and Al + 3. The results of soil chemical properties show that seasonality exerted greater influence on the results of Na +, K + and interstitial salinity. The intertidal mangrove presented nutrient content of higher soil when compared to the supramaré mangrove. In general, there was a relation to the concentration of the soil nutrients with the concentration of nutrients in leaf litterfall, more evident in the high carbon concentration, as well as the lifting conditions content of some nutrients in leaf litterfall of supramaré mangrove during the rainy season.
Acesso aberto (Open Access)
Avaliação ambiental dos recursos hídricos, solos e sedimentos na área de abrangência do depósito de resíduos sólidos do Aurá - Belém-PA
(Universidade Federal do Pará, 2002-03-27) PIRATOBA MORALES, Gundisalvo; FENZL, Norbert; http://lattes.cnpq.br/6834981018643186
With 1.754.099 inhabitants, the municipality of Belém produces roughly 1,200 tons per day of all kinds of waste, which are deposited in a landfill known as Lixão do Aurá, bordering the municipality of Ananindeua. During the past 11 years, this area has been accumulating approximately three million and two-hundred thousand tons of solid waste, transforming that place into a permanent local source of anthropogenic pollution, altering environmental conditions and resources around the whole area surrounding it. A Vertical Electrical Resistivity Sounding (VERS) procedure, conducted in the area before it was transformed into the landfill (1991), compared with the measures taken eight years later (1998), show that the land resistance has considerably dropped, with values in some cases — 109 times smaller than the original ones, thus indicating that the layers have been affected by the leach from waste decay. Fifteen profiles were conducted in the area, using the electrical imaging system, allowing us to confirm the (VERS) results, with evidences that the underground water has been affected by the infiltration and by the leachate vertical and horizontal movements. The hydro geological characteristics in the area show that the local predominant type of aquifer is of the free kind, locally confined, with hydraulic gradient of approximately 0.695%, effective porosity of 28%, permeability coefficient ranging from 1.1 x 10-3 to 0.9 x 10-4 cm/s, and underground flows running north/south towards the Guamá River, at approximately 14.79 m/year. A multivariate statistical analysis has shown that superficial water samples, collected simultaneously at three control points, during one tide cycle, regardless of the season, portray totaily different behaviors, indicating that superficial water resources are being affected by the superficial movement of leachate. With the concentration value figures for each of the leachate parameters (pH, conductivity, alkalinity, ammonia, total organic carbon, chloride, sodium, potassium, calcium, and magnesia), plus the flow of the Aurá River at the control point near the Guamá River, it is possible to estimate the quantity of pollutants that the solid waste landfill sends into the water system. During one tide cycle, in the dry season, the solid waste landfill deposits approximately 13,115 kg of chloride, 417 kg of ammonia, and 129,767 kg of salts in the local water system. For the underground waters, the multivariate statistics showed that the samples collected In the monitoring wells in the area show significant differences, indicating that the wells located downstream have been affected by the leachate. The presence of sand layers right in the area where solid waste is deposited allows for the vertical and horizontal movement of the different pollutants originated by the leachate. The heavy metais anaiyses, conducted under the sequential extraction methodology, showed percentages in the geochemical phases potentially bio-available in the studied soil and sediment samples. In the soil samples, the potentially bio-available fraction (replace, reduce, and organic geochemistry phases) contained an average of 32% of the total Cadmium (Cd), 11.8% of the total Chromium (Cr), 23% of the total Copper (Cu), 12.32% of the total Nickel (Ni), 43.1% of the total Lead (Pb), and 31.01% of the total Zinc. The potentially bio-available phases percentage in the sediments of the area was greater than the ones found in the soil samples. In these sediments, the quantity of heavy metais in the potentially bio-available fraction, shown higher values during the dry season than during the rainy season; for instance, 33% of the total Cd measured during the rainy season increased to 37% in the dry season; Pb increased from 61 to 70%; Zn, from 51 to 54%, among others. The metais analyzed by total attack in the soil samples, compared with the sandstone backgrounds, indicate that the Fe (3.1%), Cu (18.5 ppm), Ni (10.1 ppm), Pb (69.5 ppm), Cr (76 ppm), and Cd (>1 ppm) are above normal standards. In the case of sediment samples, the EPA background values (total concentration) would be moderately polluted by Cr (average 64.6 ppm) and heavily polluted by Fe (3.8%) and Mn (600 ppm). These results show that the sediments were not polluted by Pb and Zn. Considering the potentially bio-available phase and using the tool provided by a Geographic Information System (GIS), we can say that, during the rainy season, the sediment samples were not polluted by Cr (potentially bio-available fraction smaller than 20% of the total) were highly polluted by Pb and Zn (PBD higher than 50%), and moderately polluted by Cu, Ni, and Cd (PBD between 20 and 50%).
Acesso aberto (Open Access)
Avaliação da exploração florestal de impacto reduzido em atributos físicos e químicos do solo e na regeneração natural em Paragominas, PA
(Universidade Federal do Pará, 2008) HIRAI, Eliana Harumi; SILVA, José Natalino Macedo; http://lattes.cnpq.br/0479038232182214; CARVALHO, Cláudio José Reis de; http://lattes.cnpq.br/5976057799163293
This work was carried out at Fazenda Rio Capim, property of the Cikel Brasil Verde Madeiras Ltda., in the municipality of Paragominas, State of Pará, Brazil. The main objective was to study the effect of logging on the physical and chemical properties of the soil and on natural regeneration in three Working Units logged in 2000, 2003 and 2006., The treatments were gap center, primary and secondary skid trails, logging landing and one control plot. The diameter of each individual was measured at approximately 1,30 m of the ground; all species were identified and calculated the species richness, abundance, diversity Index, evenness and floristic similarity. Samples of litterfall were collected in same the locations of soil plots. For physical analysis (granulometry, texture, soil bulk density, resistance to the penetration, porosity and volumetric humidity) soil samples were collected at 0-5, 5-10, 10-20, 20-30 cm depth, and for the chemical analysis (pH, carbon stock and nitrogen, C/N) the samples were at 0-10 cm depth. In the primary skid trails it was considered its beginning, middle and end of the extension, and both for primary and secondary skid trails, the marks of the wheels of the machinery (RM), the place between the wheels (ER), and the edges of the trail (BT). Felling gaps were randomly measured and classified with areas <600m2 and> 600m2. The soil of the study areas is Yellow Latosol with very clay texture. The soil bulk density and porosity varied significantly among years and between treatments (p <0,001); no significant differences were found at 20-30 cm depth. Main and secondary skid trails and logging landings were the most affected treatments. Gaps had no influence on bulk density. It was verified that ER and BT did not differ statistically. The comparison among beginning, middle and end of the skid trails showed ere no significant differences for any of the comparisons. Results for to resistance to penetration were very similar to the bulk density and porosity. Volumetric humidity varied according to the combination year x treatment (p <0,001). Average pH values varied between 4,72 to 5,92. Litterfall decreased as time elapsed since logging. Average contents of C varied between 25,94 to 42,59 g.kg-1 and the contents of N between 2,23 to 3,35 g.kg-1, both considered as high values. For carbon stock of (Mg.ha-1) it was not found significant difference for any of the interactions (year, season and treatment). The relationship C/N for logged forest showed values between 10,37 and 15,42, indicating mineralization of the soil inorganic nitrogen. The three studied WUs presented high diversity and evenness. WUs logged in 2000 and 2003 showed the highest similarity (35,93%), followed by the WUs logged in in 2003 and 2006 (33,46%), and WUs logged in 2000 and 2006 (26,93%). It has been concluded that it is necessary a long observation period for evaluation of the effects of soil compaction on the growth of the regeneration. Indicators for good forest management practices should consider soil attributes (physical, chemical and biological) for a better understanding of the system and choice of other indicators that can give answers on the equilibrium of the forest ecosystem. The studied parameters can be used as indicators of environmental quality.
Acesso aberto (Open Access)
Avaliação do processo de cobertura da terra no entorno de usinas hidrelétricas na Amazônia brasileira: a evolução da UHE de Tucuruí
(Universidade Federal do Pará, 2018-05-16) MONTOYA, Andrés Danilo Velástegui; LIMA, Aline Maria Meiguins de; http://lattes.cnpq.br/6572852379381594
The analysis of the environmental impacts produced by the construction of megaprojects in the Amazonia has been the field of study of several researches. In this work, the object of study was the Tucuruí hydroelectric power plant, built in the state of Pará. Since it is a strategic region for the expansion of the capacity of hydroelectric power generation of Brazil, it has been the focus of several analysis approaches aimed at subsidizing the best characterization of future scenarios. The model of land cover change was discussed in the riparian areas and in the surroundings of the reservoirs, motivated by the modification of the dynamics of the natural ecosystems. This phenomenon is caused by the extensive reservoirs and migratory aspects, in an already consolidated situation. It was carried out a multitemporal mapping and analysis of Landsat satellite images of the representative dates of the different stages of construction, inauguration, expansion and current scenario of the hydroelectric power plant. It was also sought to verify if the increase of the anthropic areas, in the municipalities directly affected by the reservoir, have a compensatory role in the improvement of the socioeconomic conditions in the region. In fact, these regions absorb the social, economic and environmental costs associated with the construction and operation of the plants, while the energy benefits are distributed to other regions of the country. It is hoped, therefore, to contribute with a critical evaluation of the new hydroelectric plans, predicting the possible environmental and social impacts of the project, given the history of events already observed in the Tucuruí hydroelectric power plant. Also, to contribute to the debate on elements that induce "regional development", thus subsidizing public management, the private sector and the academic community, regarding the formulation and implementation of actions aimed at the improvement of life quality in these localities.
Acesso aberto (Open Access)
Avaliação econômica de sistemas agroflorestais no nordeste paraense: os sistemas agroflorestais como instrumento de política pública de desenvolvimento socioeconômico e ambiental regional
(Universidade Federal do Pará, 2013-01-08) OLIVEIRA, Dimitri Maurício Queiroz de; ALMEIDA, Oriana Trindade de; http://lattes.cnpq.br/0325909843645279
This study aims to evaluate the economic viability of two agroforestry (SAF) in the municipality of Tomé First proceeded to the literature of the legal requirements for the use of specially protected areas, then sought to frame the agroforestry systems over an optical environmental and socio- economic, as an instrument of use and recovery of these areas by evaluating the economic returns from two models of SAF observed in Tomé-Açú. For the progress and completion of this study utilize is a documentary research, bibliographical and field research through interviews with local actors production chain in the city of Tome - Açú. The methodology des survey data used for this study was the semi-structured interviews with local stakeholders. The tabulation of this date, as well as the results of analyzes was performed with concepts economic-mathematical engineering economic evaluation of investment projects through cash flow, NPV, IRR and Rb/c of arrangements. The conclusion discusses the concept of viability-studied arrangements for the current economic scenario of cultures composing the models studied as an alternative source of investment.
Acesso aberto (Open Access)
Avaliação geoquímica da contaminação por mercúrio dos sedimentos de correntes e solos do distrito mineiro de Zaruma-Portovelo, república do Equador
(Universidade Federal do Pará, 1996-05-31) MALDONADO RAMIREZ, Roque Vicente; RAMOS, José Francisco da Fonseca; http://lattes.cnpq.br/8189651755374537
Auriferous occurrences are known in the area of Zaruma-Portovelo, Ecuador, since the pre-Columbian period, but it was only from the end of the 70's that a very intense mining activity started to be developed. Miners in the sector carry out the activities of exploration, exploitation and processing of polymetallic ore using rudimentary techniques, which causes contamination of rivers, soil and atmosphere by mercury and other heavy metals, in addition to cyanide. They still deforest the area, as they use wood in the security structures of the mineral galleries. The deposit in the mining district of Zaruma-Portovelo is of hydrothermal, polymetallic origin, occurring in a complex of andesitic volcanic rocks of the Celíca Formation. The ore is composed of the sulphides pyrite, chalcopyrite, galena, sphalerite and bornite, among others, in addition to the gangue minerals quartz and calcite. The metals Cd, Zn, Pb and Cu are released from these minerals. Mercury is of anthropogenic origin, as it is used in the extractive metallurgy of gold, as is cyanide, which is used in a second phase of the gold recovery process. The present work had as objective the identification and geochemical evaluation and the description of the activities of the sources of pollutants, especially mercury, through the collection and analysis of samples of bottom sediments, soils and mining tailings, in addition to making a brief description of the activities from the mine. A sampling campaign was carried out at the end of the dry season, having collected 26 samples of bottom sediments, 23 of soil and 4 of tailings. At 5 points soil samples were taken in profiles with intervals of 2 cm to a depth of 14 cm. A study of the distribution of metals in the different granulometric fractions of the sediments was also carried out. Samples were collected in triplicate at three points to determine the variability of the results. The concentrations of Hg(total) in soils indicate that 83% of the samples are above the background (103ppb) with minimum and maximum values of 109 and 9,546 ppb and an average of 662 ppb, with the highest concentrations occurring in samples close to the emission sources, which are the mills (processing plants). In all profiles, it was found that the highest levels occur in the upper part, gradually decreasing with depth. In the bottom sediments, in addition to Hg(total), the elements Pb, Zn, Cd and Cu were analyzed in the exchangeable fraction, observing anomalous values for all these anomalous values concentrated mainly in the drainages of the Calera and Amarillo rivers, after the junction with the Calera River, which has most of the area's processing plants on its banks. High levels of Hg, Zn, Pb, Cd and Cu were observed in the mining tailings samples, confirming that artisanal beneficiation processes, in addition to generating pollution, cause economic losses due to the low recovery of metals. Tests to verify the amounts of mercury used by miners for amalgamation show that 95 to 97% of the mercury is released into the atmosphere in the amalgam burning stage. The rest is released in liquid form in the soils and drainages of the area. This shows the importance of developing an education policy for prospectors, offering new alternatives and technologies to avoid the burning of amalgam in the open air, which would greatly contribute to the reduction of mercury contamination.
Acesso aberto (Open Access)
Caracterização dos atributos físicos e químicos de solos em áreas ex situ e in situ da ilha de germoplasma, uma reserva ambiental em Tucuruí, Pará
(Universidade Federal do Pará, 2020-03-09) NERI, Pablo Paulo Souza; VILHENA, Karyme do Socorro de Souza; http://lattes.cnpq.br/3071495983880548; https://orcid.org/0000-0001-9661-6683
The construction of hydroelectric power plants in the world is based on increasing demand for energy and river flood control. At the national level they are alternatives due to the great Brazilian hydroelectric potential. The Tucuruí Hydro-Power Complex is located in the Tocantins-Araguaia Basin and over 1,100 islands have been formed from the filling of the reservoir, inhabited by some 6,500 people, most of whom have vegetable extraction and animal husbandry as their source of income. Among these islands, one can highlight the Germoplasma Island, which is a permanent preservation area (APP) and is located 3 km from the Tucuruí dam. This island was created in order to guarantee the conservation of the plant genetic material of the region flooded by the dam. On the island of germplasm, some forest matrices planted on the courts are perishing. In other courts the productivity of the forest species is decreasing. This problem can hinder the extraction of seeds for seedling production and propagation. The purpose of this research was to determine the physical and chemical attributes of the soil and characterize the area in situ (PC3), shade planting (Q18) and full sun planting (Q17) ex situ area of the germplasm island located in the lake of the Tucuruí hydroelectric power station. Deformed composite samples were collected from 10 to 30 sub-samples in each area at depths of 0-10cm and 10-20cm. The samples were then prepared and analyzed in the Civil Engineering Laboratory of the Federal University of Pará at the Tucuruí University Campus. The chemical and physical results of the soils were submitted to the Tukey statistical test at 5% probability, Hierarchical Grouping Analysis (HCA) and Principal Component Analysis (PCA). The results of the soil chemical and physical analyses made it possible to understand the characteristics of the germplasm island areas. The highest levels of calcium and magnesium were found in Q17, due to the management performed in the plantation. Moreover, it presents high weathering and low organic matter content, and therefore, low Cation Exchange Capacity. In relation to the Q17 and Q18 planting areas, the shading planting provides the best conditions for the development of plant species and maintenance of soil quality, as it showed similarity between the chemical attributes of the natural vegetation area. From the data obtained and statistical analysis, there was greater similarity between the areas PC3 and Q18. Through the results of the Principal Component Analysis (PCA) it was possible to visualize the contribution of soil chemical attributes in the characterization of the studied areas. The soil chemical attributes that contributed the most were: ∆pH (-0.333), Al3+ (-0.332) and pH H2O (0.323), H+ (-0.534), Fe2+ (0.410) and AP (-0.379). Hierarchical Component Analysis (HCA) confirmed the results obtained in Principal Component Analysis (PCA).
Acesso aberto (Open Access)
Carbon content in Amazonian Oxisols after forest conversion to pasture
(2009-12) SILVA JÚNIOR, Mário Lopes da; DESJARDINS, Thierry; SARRAZIN, Max; MELO, Vânia Silva de; MARTINS, Paulo Fernando da Silva; SANTOS, Elaine Rodrigues; CARVALHO, Claudio Jose Reis de
Soil plays an important role in the C cycle, and substitution of tropical forest by cultivated land affects C dynamic and stock. This study was developed in an area of expansion of human settlement in the Eastern Amazon, in Itupiranga, State of Pará, to evaluate the effects of native forest conversion to Brachiaria brizantha pasture on C contents of a dystrophic Oxisol. Soil samples were collected in areas of native forest (NF), of 8 to 10 year old secondary forest (SF), 1 to 2 year old SF (P1–2), 5 to 7 year old SF (P5–7), and of 10 to 12 year old SF (P10–12), and from under pastures, in the layers 0–2, 2–5 and 5–10 cm, to evaluate C levels and stocks and carry out separation of OM based on particle size. After deforestation, soil density increased to a depth of 5 cm, with greater increase in older pastures. Variation in C levels was greatest in the top soil layer; C contents increased with increasing pasture age. In the layers 2–5 and 5–10 cm, C content proved to be stable for the types of plant cover evaluated. Highest C concentrations were found in the silt fraction; however, C contents were highest in the clay fraction, independent of the plant cover. An increase in C associated with the sand fraction in the form of little decomposed organic residues was observed in pastures, confirming greater sensitivity of this fraction to change in soil use.
Acesso aberto (Open Access)
The ceramic artifacts in archaeological black earth (terra preta) from Lower Amazon Region, Brazil: chemistry and geochemical evolution
(Instituto Nacional de Pesquisas da Amazônia, 2004-09) COSTA, Marcondes Lima da; KERN, Dirse Clara; PINTO, Alice Helena Eleotério; SOUZA, Jorge Raimundo da Trindade
This paper carried out a chemical investigation of archaeological ceramic artifacts found in archaeological sites with Black Earth (ABE) in the Lower Amazon Region at Cachoeira-Porteira, State of Pará, Brazil. The ceramic artifacts, mostly of daily use, belong to Konduri culture (from 900 to 400 years BP). They are constituted of SiO2, Al2O3, Fe2O,3, Na2O and P2O5; SiO2 and Al2O3 together add up to 80 % and indicate influence of acid rocks, transformed into clay minerals basically kaolinite. The relative high contents of P2O5 (2.37 % in average) come out as (Al,Fe)-phosphate, an uncommon fact in primitive red ceramics, but found in some roman and egyptian archaeological sites. The contents of the trace elements are similar or below the Earth's crust average. This chemical composition (except P2O5) detaches saprolite material derived acid igneous rocks or sedimentary ones as the main raw material of the ceramics. The contents of K, Na and Ca represent the feldspars and rock fragments possibly introduced into saprolitic groundmass, indicated by mineralogical studies. The presence of cauixi and cariapé as well as quartz sand was confirmed by optical microscope, SEM analyses and by the high silica contents of ceramic fragments. Phosphorus was possibly incorporated into groundmass during cooking of foods, and ABE soil profile formation developed on yellow Latosols. The raw materials and its tempers (cauixi, or cariapé, feldspar, crushed rocks, old ceramic artifacts and quartz fragments) are found close to the sites and therefore and certainly came from them.
Acesso aberto (Open Access)
Dispersão geoquímica dos elementos Si, Al, Fe, Mn, Na, K, Cu e Zn nos solos e sua aplicação na caracterização de áreas geoquimicamente homogêneas
(Universidade Federal do Pará, 1980-05-13) SILVA, Waldise Rossycléa Lima da; RONCAL, Juan Rolando Zuleta
Variations in the chemical composition of soils are used to characterize sub-areas geochemitally homogenous. The aplication of this methodology in a tropical humid region of accentuated topography constitute the principal objective of the present research. Samples of red latosols (Horizon B) developed over gravite, sandstone and basalt occurring in the Central Granite Region of the Serra dos Carajás, Pará State, Brasil were analized for the elements Si, AL., Fe, 40Mn, Na, K, Cu e Zn, by atomic absorption spectrophotometry. Based on the criterion of similarity in the chemical composition (Cluster Analysis, Factor Analysis) the soils were separeted in to different groups. The geographical distribution of the different groups permit the establishment of a Glose relationship between the different parent lithologies and their corresponding soils.
Acesso aberto (Open Access)
Efluxo de CO₂ do solo e biomassa de raízes finas ao longo de um gradiente topográfico na Floresta de Caxiuanã-PA
(Universidade Federal do Pará, 2013-05-07) CASTRO, Sirlene de Lima; CATTANIO, José Henrique; http://lattes.cnpq.br/1518769773387350
The objective of this research was to understand the role of small topographic elevations in the soil carbon dioxide (CO2) efflux comparing different seasonal period in the National Forest of Caxiuanã, oriental Amazon. Were selected two transects with about 17m topographic gradient, the first initiated near the border of a permanent stream and the second standing near an intermittent stream, denominate in this work as Transect1 and Transect2, respectively. In each transect were selected four locations for the collection and measurement of data called lowland, middle lowland, middle plateau and plateau. At these sites were conducted CO2 efflux and soil temperature analysis, and soil samples for organic carbon analysis and fine root (<2 mm) biomass studies at different depth intervals. It was observed a significant difference in the soil organic carbon concentration compared in the soil surface layer (0-10 cm) in lowland topography, where the transect that begins in the board of the intermittent stream had the significantly higher organic carbon content. It was also observed a soil organic carbon reduction with depth, but there were no differences in organic carbon content with topographic variation. Bringing together both transects, the results related to superficial fine root biomass, it was found mean values of 382.47 ± 25.46 g m-2 for the dry months and 298.24 ± 23.50 g m-2 for the rainy months. In general there was a reduction in fine root biomass by increasing the soil depth, and in the surface layer (0-30 cm) is concentrated to greater root biomass with more than 80% of total root biomass for both transects. There were significant differences in root biomass among and within transects. For the same time, it was founded higher CO2 efflux in the lowland topography compared to the plateau. Seasonal variation also has effect on soil CO2 efflux, with the month of August (transitional month) having the highest CO2 effluxes and March (rainy month) the lowest CO2 efflux, independent of topographic position.
Acesso aberto (Open Access)
Efluxo de dióxido de carbono do solo na transição floresta-sistema agroflorestal no município de Tomé Açu, Pará
(Universidade Federal do Pará, 2015-08-31) PINHEIRO, Larissa Paulina Souza; VASCONCELOS, Steel Silva; http://lattes.cnpq.br/0719395243841543
The soil carbon dioxide (CO2) efflux corresponds to the principal flow of carbon from the biosphere to the atmosphere. Tropical soils, which usually show high moisture and temperature, offer very favorable conditions for the production of CO2 resulting from, the decomposition of organic matter, root respiration and microbial respiration, increasing soil CO2 emission to the atmosphere. Soil management practices influence the controlling factors of the soil carbon stock and CO2 emission. A greater understanding of this influence has stimulated studies on all ecosystems, which, among other things, seek to identify and/or develop practices that increase carbon storage and reduce the emission of soil CO2, as is the case of agroforestry. Due to the large global scientific interest in understanding the physical and biological processes involving CO2 fluxes between the surface and the atmosphere, the aim of this research was to evaluate the effects of the transition from secondary forest to oil palm-based agroforestry systems on the soil CO2 efflux and soil biotic and abiotic factors. The experiment was conducted in the municipality of Tomé Açu, northeast Pará, in a project which has been investigating models of palm oil production systems in agrosilvicultural arrangements in the context of smallholder agriculture. The soil CO2 efflux was measured with a portable photosynthesis measurement system (LI-6400) coupled to a soil respiration chamber. We also measured soil gravimetric moisture and temperature, soil respiration (SR), microbial biomass carbon (MBC), soil organic carbon, fine roots stock and litter stock in two AFS and a remaining secondary forest. Measurements of CO2 efflux and soil and plant sampling were taken between January and April 2015 and were carried out fortnightly. The soil CO2 efflux was mainly influenced by soil temperature and moisture in both agroforestry systems. The forest-AFS transition significantly affected the soil CO2 efflux, fine roots, MBC and SR. The transition from secondary forest to AFS with oil palm and the spatial variability of the species or arrangement of the systems affected the soil quality. These changes may be linked to impacts of changes in the structure and species composition of the systems and the management of soil organic matter.
Acesso aberto (Open Access)
Estudo em laboratório de anomalias de potencial espontâneo
(Universidade Federal do Pará, 1978-11) FERREIRA, Lindalva do Carmo; ALVAREZ BEJAR, Román
This work is an application in the laboratory of the Spontaneous or Self Potential method of field geophysics. Pairs of differente rocks and residual soils were placed in contact in the laboratory to determine whether they could produce a difference in potential, as had been occasionally observed during field investigations. The samples of rock used are limestones, basalts, and rhyolite from the area of "Caldera de Los Humeros" in Mexico. The residual soils are from the area MM1 of "Serra dos Carajás", Pará, Brasil. The measurements were carried out using dry systems (room humidity) and humid systems (water added). The changes of measured potential for rocks and soils in the laboratory show differences in average values ranging from 5mv to 50 mv from one side of a contact to the other. Thus, the result of this investigation in positive and indicates that changes in Self Potential values can originate from changes in superficial soil type or by contacts between different types of rocks.
Acesso aberto (Open Access)
Evolução mineralógica e geoquímica multi-elementar de perfis de solos sobre lateritos e gossans na Amazônia
(Universidade Federal do Pará, 1995-07-31) HORBE, Adriana Maria Coimbra; COSTA, Marcondes Lima da; http://lattes.cnpq.br/1639498384851302
With the aim of studying the genesis of soils developed on lateritic crusts, five profiles located in the region of Carajás (N5 and Igarapé Bahia procpects) as well as in Paragominas (Camoaí Mine) and Belém (Mosqueiro and Outeiro Beaches) municipalities all them located in Pará State, Brazil - have been selected. Based on the structures described in the profiles (N5, igarapé Bahia, Camoaí, Outeiro and Mosqueiro), it has been Possible to distinguish four differents horizons: fresh crust, partially-weathered crust, weathered crust and soil. The fresh crust is compact, vacuolar and composed of iron and aluminium oxyhydroxides. The partially-weathered crust is made up of fresh-crust relicts enclosed in yellowish or reddish clayey matrix, depending on the mineralogical composition of the fresh crust. The weathered crust is characterized by dominance of clayey matrix in relation to relicts, while the soil is composed exclusively of clayey material. The structures of the profiles show that the change from fresh crust to the overlying soil is gradual with volume expansion at the beginning of the fragmentat ion processes. This expansion is followed by the collapse of the profile as the relicts are entirely transformed into an earthy micro-aggregated material. The profiles of N5 and Igarapé Bahia prospects have been derived from a mature iron-aluminous crust, being characterized by the highest contents of kaolinite and hematite either in the crust or in the relícts. Gibbsite Al-goethite, anatasse and quartz are concentrated in the soil, which tends to be initially bauxitic, at the base of the profile, and to become kaolinite-rich toward the top. The mineralogical changes led to chemical modifications such as decrease in Fe2O3 and 8iO2 and increase in Al2O3, TiO2 and PF. The trace elements (V, Cr, Ni, R, Mo, Zr, Ga, Sc, Y, Mn, Cu and Pb besides Au in the profile of Igarapé Bahia) and REE's exhibit concentrations of 8 and Zr whereas the remaining ones tend to be progressively diluted from the crust toward the soil. The TiO2-mass balance shows that the transformation of the crust into soil took place by means of leaching of SiO2 and Fe2O3 in two profiles above mentioned, while Al2O2 underwent enrichment in the profile of N5 and leaching in the profile of igarapé Bahia. The soil formation from a mature aluminous crust in Camoaí differs from those described in the profile of Igarapé Bahia and of N5 in that it shows a decrease in gibbsite contents and an increase in kaolinite and quartz, whereas the verey low contents of ,hematite, goethite, and anatase do not present a characteristic distribution. The trace elements and the REE's, with contents much lower than those observed in the others profiles, show an increase in Zr and Mn toward the soil horizon and a dilution of the remaining ones. In the Camoaí, the transformation of the aluminous crust into soil, based on the TiO2-mass balance, took place through leaching of Al2O3 and enrichment in SiO2 and Fe2O3. In the profiles of Outeiro and Mosqueiro, deriveci from immature silicoferruginous lateritic crust the soil formation occurred by means of decreasing in hematite+goethite so that, in the resulting soil, quartz and kaolinite predominate. In consequence of this, a decrese in the Fe2O3 contents and an increase in SiO2 and Al2O3 have been observed in those profiles. The trace elements distribution presents, as in igarapé concentration of Zr and dilution of the remaining ones. Based on TiO2-mass balance, it could be noticed that the transformation of the crust in the profiles of Mosqueiro and Outeiro took place through leaching of Fe2O3, whereas SiO2 and Al2O3 underwent enrichment in the profile of Outeiro and Leaching in the one of Mosqueiro. On the basis of structures, mineralogical composition and geochemical data of the profiles, it has been possible to characterize an accentuated process of Fe loss in the iron-aluminous and in the silicoferruginous crust as well as Ai removal in the aluminous ones what led to soil generation. In the profiles derived from the iron-aluminous and the silicoferruginous crust, it has been observed substitution of hematite by Al-goethite, an intermediated segment - where there is predominance of gibbsite in the iron-aluminous profiles -- and presence of kaolinite at the top of both profiles. In every profiles, it has been reported quartz acumulation. The enrichment in quartz and the S1O2 being the latter likely come from externai sources -via vegetable-material decay - caused the neoformation of kaolinite from gibbsite in the profiles of N5, igarapé Bahia, and Camoaí. In the profiles of Mosqueiro and Outeiro the kaolinite presence in the soil is a consequence of its relative enrichment in the relation to the crust from which it has been derived. As a consequence of the mineralogical transformation, Fe has been leached from the profiles of N5, Igarapé Bahia, Mosqueiro, and Outeiro and Al from those of the Camoaí, as well as V, Cr, Mo, Ga, Sc, Cu, Pb and REErs. On the other hand, a strong enrichment in Zr and, in part, in 8 and Mn has been reported in every stud ied profiles. The transformations that caused the break down of the balance of the crusts, their desmantlement and comminution, forming relicts and a new clayey mineral phase, are consequence of organic matter influence which turns the environments conditions more acid and less oxidizing, in a process similar to that of weathering-profiles formation in humid tropical environments. The mineral and chemical difference observed between the profiles are consequence of compositional variation of the crusts which, in part, also reflect the degree of maturity of theirs. The mineralogical and geochemical characteristics of the soils in the investigated profiles allow us to correlate them to the Belterra Clay and, in consequence of this, to admit that Belterra Clay had an autochthonous origin in relation to the underlying lateritic crusts.
Acesso aberto (Open Access)
Fluxo de óxido nitroso (N2O) do solo em um sistema agroflorestal em Tomé Açu, nordeste do Pará
(Universidade Federal do Pará, 2013-08-14) SOUZA, Gisele Nerino Brito de; VASCONCELOS, Steel Silva; http://lattes.cnpq.br/0719395243841543
The study on the emission of nitrous oxide (N2O) from soil in agricultural systems contributes to the understanding of global climate change, which could aid in minimizing negative impacts on the environment. The importance of this gas due to its direct relationship with the global greenhouse effect and to stratospheric ozone depletion. Some agricultural practices performed in agroforestry systems, when managed correctly can help curb these negative impacts. The use of legumes in these systems has become increasingly common, but its relationship with N2O emissions is still not well understood. Given the importance of processes and factors contributing to the increase in N2O emissions, this study aimed to examine the contribution of legume species (Inga edulis Mart.) And non-legume (Theobroma cacao) in nitrous oxide emissions from soil to the atmosphere through the use of static cameras and different climatic characteristics in an agroforestry system in the city of Tome Açu northeastern state of Para the experiment was conducted in an area of agroforestry (SAF) located in Tome Acu ( PA ) ( 02 ° 33'38 , 5 " S , 48 ° 21'36 , 1 " W ) within the February/2013 August/2012, totaling 11 field campaigns, a fortnightly basis. Static chambers of circular type (diameter = 300 mm ) and rectangular ( 37.5 cm x 57 cm ) were used to determine the emission of N2O from the soil, with the aid of polypropylene syringes with a volume of 20 ml and transferred to flasks borosilicate. The N2O concentration was determined by gas chromatography using a gas chromatograph Varian CP 3800 gas model with an electron capture detector. The variation of N2O emissions were 2.74 to 42.54 mg N m-2 h-1 pulses to and from 1.65 to 30.46 mg N m-2 h- 1 for non-legumes. Higher emissions were observed in the wet season compared to the dry season. The gravimetric soil moisture, soil temperature and inventory of plant residues on the soil were the factors that most N2O emissions from the soil.
Acesso aberto (Open Access)
Fluxos de CO2 do solo na Floresta Nacional de Caxiuanã, Pará, durante o experimento ESECAFLOR/LBA
(2013-03) SILVA JUNIOR, João de Athaydes; COSTA, Antonio Carlos Lôla da; AZEVEDO, Pedro Vieira de; COSTA, Rafael Ferreira da; METCALFE, Daniel B.; GONÇALVES, Paulo Henrique Lopes; BRAGA, Alan Pantoja; MALHI, Yadvinder Singh; ARAGÃO, Luiz Eduardo Oliveira e Cruz de; MEIR, Patrick
The ESECAFLOR/LBA experiment was carried out at the Caxiuanã National Forest, Pará State, and this article intends to investigate the effect of hydrological stress on the total soil respiration. Two adjacent 1 hectare plots were defined in January 2002. One plot remained in its natural conditions and was used as a control (A), while in the exclusion plot (B) plastic cover panels were installed in order to drain about 70% of the total rainfall to outside of the plot. Accumulated monthly rainfall was recorded from 2005 January to December. During 2005 the rainfall over the ECFPn was 2,211.6 mm, or 9.96% above the mean of 2,011.2 mm. The average soil moisture was 15.6±9.2 and 9.5±3.4% in the plots A and B, respectively. The average soil temperature was 25.6±0.4 and 25.7±0.5 ºC, for the A and B plots, respectively. The average soil CO2 flux was 3.46±0.44 and 3.21±0.84 μmolCO2 m-2s-1 in the A and B plots, respectively. With the exclusion of part of rain in plot B, it had a reduction of 7.23% in the soil CO2 flux (0.25 μmolCO2 m-2s-1), 39.1% in the soil humidity (6.1p.p.), and an increase of 0.39% in the soil temperature (0.1ºC). The soil moisture in parcel B was lesser than in the parcel A, due to the exclusion system of rain. However at the beginning of the year, site B undergone some changes causing the measuring values to be about the same on both areas.