EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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18 resultados
Resultados da Pesquisa
Item Metabarcoding of soil fungal communities in rupestrian grassland areas preserved and degraded by mining : implications for restoration.(2023) Figueiredo, Maurílio Assis; Silva, Thamar Holanda da; Pinto, Otavio Henrique Bezerra; Leite, Mariangela Garcia Praça; Oliveira, Fábio Soares de; Messias, Maria Cristina Teixeira Braga; Rosa, Luiz Henrique; Câmara, Eduardo Aguiar Saraiva; Lopes, Fabyano Alvares Cardoso; Kozovits, Alessandra RodriguesRupestrian grasslands are vegetation complexes of the Cerrado biome (Brazilian savanna), exhibiting simultaneously great biodiversity and important open-pit mining areas. There is a strong demand for the conservation of remaining areas and restoration of degraded. This study evaluated, using next-generation sequencing, the diversity and ecological aspects of soil fungal communities in ferruginous rupestrian grassland areas preserved and degraded by bauxite mining in Brazil. In the preserved and degraded area, respectively, 565 and 478 amplicon sequence variants (ASVs) were detected. Basidiomycota and Ascomycota comprised nearly 72% of the DNA, but Ascomycota showed greater abundance than Basidiomycota in the degraded area (64% and 10%, respectively). In the preserved area, taxa of different hierarchical levels (Agaromycetes, Agaricales, Mortierelaceae, and Mortierella) associated with symbiosis and decomposition were predominant. However, taxa that colonize environments under extreme conditions and pathogens (Dothideomycetes, Pleoporales, Pleosporaceae, and Curvularia) prevailed in the degraded area. The degradation reduced the diversity, and modified the composition of taxa and predominant ecological functions in the community. The lack of fungi that facilitate plant establishment and development in the degraded area suggests the importance of seeking the restoration of this community to ensure the success of the ecological restoration of the environment. The topsoil of preserved area can be a source of inocula of several groups of fungi important for the restoration process but which occur in low abundance or are absent in the degraded area.Item Native grass sod and plug production as an alternative technique to restore neotropical rupestrian grassland after mining.(2023) Figueiredo, Maurílio Assis; Messias, Maria Cristina Teixeira Braga; Leite, Mariangela Garcia Praça; Kozovits, Alessandra RodriguesDespite the importance of grasses in the structure and functioning of tropical grasslands, there is still a lack of efficient and economically viable techniques to produce and introduce grasses in restoration projects. Here, we evaluated the sod and plug-plant production and planting of a native grass from Brazilian rupestrian grasslands, Sporobolus metallicolus, in a post-bauxite mining. To produce the sod, we used post-mining substrate and its mixture with commercial substrate. Then, we sowed 270 seeds of S. metallicolus on a 4-cm layer of substrate in 144-cm2 trays. Eighty days after sowing, we subdivided the contents of each tray (substrate + plant) into 4 × 3–cm plug-plants. Plug-plants were planted in the degraded area with and without the incorporation of litter from an adjacent conserved rupestrian grassland. We also evaluated the cost of production of each plug-plant. The mixture of substrates provided greater plant growth and rooting, obtaining plug-plants with an average of 13 individuals, dry mass of 270 mg, and estimated cost of US$ 0.0045. In the degraded area, the addition of litter increased shoot biomass gain. Plant survival was 100% with and without litter addition and the plants started seed dispersal at 7 months after planting. The production of S. metallicolus plugs with the mixed substrate and the growth of plants in the post-mined area showed promising results and reduced costs, indicating technical and financial feasibility. The presented techniques can be an option for introducing grasses in degraded areas and optimize the use of seeds.Item Seed covering and dry periods in the rainy season interfere with direct seeding success in the restoration of post-mined grasslands.(2021) Figueiredo, Maurílio Assis; Messias, Maria Cristina Teixeira Braga; Leite, Mariangela Garcia Praça; Kozovits, Alessandra RodriguesAmong the limitations for the use of direct seeding in the ecological restoration of severely degraded areas in tropical grasslands, the association between dry periods and an inhospitable substrate stands out. This work evaluated whether covering seed with a soil layer and the addition of a thin topsoil layer to the degraded substrate interferes with native plant establishment in degraded areas. The effect of rainfall variations on direct seeding results was also measured. The establishment of seven native species was evaluated under four different conditions: 1) seeding on degraded substrate, 2) seeding covered by 1 cm degraded substrate layer, 3) seeding on 1cm topsoil layer, and 4) seeding covered by 1 cm topsoil layer. In general, species with smaller seeds showed higher establishment percentages in treatments in which seeds were deposited on the substrate. Legume species, which have larger seeds, achieved better establishment percentage when seeds were covered by the substrate. The addition of topsoil was beneficial for Bulbostylis fimbriata (Cyperaceae), while for the other species, the effect was null or harmful. Data also showed that rainfall amount and distribution affected the establishment rate. Direct seeding is an advantageous alternative for the ecological restoration of tropical grassland degraded by mining. Better knowledge on sowing management and behavior of native species can contribute to improving the efficiency of this technique.Item Traditional ecological knowledge in a ferruginous ecosystem management : lessons for diversifying land use.(2020) Urriago Ospina, Lina Marcela; Jardim, Clarice Morais; Rivera Fernández, Germán Marino; Kozovits, Alessandra Rodrigues; Leite, Mariangela Garcia Praça; Messias, Maria Cristina Teixeira BragaSoils developed on banded iron formations (BIFs) present severe physical and chemical limitations to the establishment and growth of non-native cultivated plants. In Brazil, these areas are extensively exploited by Fe and Al mining, causing impacts that further hamper the growth of plant species for the purpose of ecological restoration or rehabilitation. However, traditional communities have historically managed this type of environment successfully for subsistence crops. An understanding of the methods used for such purpose will help future studies of land-use diversifcation and rehabilitation in these ferruginous soils. The aim of this study was to investigate the traditional ecological knowledge (TEK) of a community with great cultural richness inhabiting areas on BIFs in Ouro Preto, Brazil. Interviewees were selected by the snowball technique. Ethnoecological methods (interviews, free lists and guided visits) were used to record the types of soil management, cultivated species and socioeconomic profle of specialists. Specialists are mainly women over 45 years old, low schooling, born and living in the area for a long period. Trial and error and vertical transmission represent the main forms of TEK acquisition. There was high diversity of praxis in the ecological soil management, as well as of cultivated species (183). The methods used are efcient for the physical and chemical soil improvement, allowing the establishment of species, increasing agrobiodiversity and diversifying land use. The used techniques can provide technologies for the rehabilitation of mined areas, confrming the importance of ethnoecological studies for this purpose.Item Chemical and microstructural behaviour of ferruginous rocky outcrops topsoils applied to degraded mining areas.(2020) Rocha, Fernanda Carolina Gomes; Oliveira, Fábio Soares de; Leite, Mariangela Garcia Praça; Dias, Diego Dayvison; Messias, Maria Cristina Teixeira Braga; Kozovits, Alessandra RodriguesTopsoil transposition is an efficient technique for recovering miningdegraded areas. However, storage time may reduce its functionality. To evaluate the effect of storage and litter addition, physical (microstructure) and chemical (fertility) properties were assessed in stored (3-months) and non-stored topsoils. Twelve months after transposition, regardless of the storage time, soil fertility and microstructure were improved, due to the mechanical work of plant roots recruited from topsoil seed bank or rain, and decomposition of pre-existing plant fragments. Litter addition did not affect chemical attributes but influenced microstructure transformations. Paedogenetic evolution was clearly fed by revegetation establishing a sustainable feedback system.Item Direct seeding in the restoration of post-mined campo rupestre : germination and establishment of 14 native species.(2021) Figueiredo, Maurílio Assis; Messias, Maria Cristina Teixeira Braga; Leite, Mariangela Garcia Praça; Kozovits, Alessandra RodriguesDirect seeding in the restoration of degraded areas requires less financial investment and facilitates the use of greater diversity of species from different functional groups than traditional planting of seedlings. However, the application of this technique in the ecological restoration of post-mined areas in grassland environments is still poorly investigated. This study evaluated seed germination under controlled conditions, seedling establishment and associated costs of 14 species native to the Brazilian campos rupestres through direct seeding in a post-mined area. The effects of the incorporation of plant material (litter) to the degraded substrate on plant establishment were also measured. Under controlled conditions, 64% (9 out of 14) of the evaluated species showed germinability between 30 and 77%. Under field conditions, one year after, it was observed that the incorporation of plant litter to the substrate allowed the establishment of 49 individuals m− 2 of nine species, four of which with establishment percentage and cost per seedling of, respectively, 1.4–6.2% and US$ 0.006–0.09. In the other treatments, no significant plant establishment was observed. Despite the low percentage of establishment, direct seeding combined with the incorporation of plant litter to the substrate allowed the revegetation of a post-mined area with viable cost. The use of suitable species for direct seeding combined with techniques that promote improvements in substrate conditions is critical to increase establishment success using direct seeding in the ecological restoration of campos rupestres post-mined areas. Further studies on techniques to improve substrate quality and seed germination of native species of campos rupestres are requiredItem Quantitative analysis of plant leaf elements using the LA-ICP-MS technique.(2019) Diniz, Adriana Pedrosa; Kozovits, Alessandra Rodrigues; Lana, Cristiano de Carvalho; Abreu, Adriana Trópia de; Leite, Mariangela Garcia PraçaThe use of Laser Ablation coupled to Mass Spectrometry is a promising technique for analysis of plant tissue elements because it has advantages over conventional digestion techniques such as reduced levels of contamination and sample preparation time, possibility of spatial distribution analysis of elements, high number of repetitions, among others. This technique still has some limitations, especially with regard to calibration, which may result in inaccurate chemical analyses. The present study aims to compare two types of analyzers (quadrupole and magnetic sector field) regarding precision and accuracy. Certified material was examined, and also plant material analyzed by both solution in inductively coupled plasma optical emission spectrometry (ICP OES) and by laser ablation methods. It was observed that the magnetic sector field analyzer gave better results in relation to precision (relative standard deviation - RSD) and accuracy (recovery). An elemental composition pattern similar to that of the sample to be analyzed is relevant to validate the methodology for the analysis of leaves collected under different environmental conditions. Thus, pulverized Eremanthus erytropappus leaves were suggested as a second type of validation standard to be used in analyzes of plants belonging to the Atlantic and Cerrado Forest biomes.Item Germinação de sementes nativas dos campos sulinos após armazenamento e choque de temperatura.(2015) Marchiori, Nidia Mara; Fidelis, Alessandra Tomaselli; Kozovits, Alessandra Rodrigues; Garcia, Queila de SouzaEstudos que avaliam efeitos de armazenamento e de choques térmicos permitem um maior conhecimento da fisiologia da espécie e possíveis inferências sobre a regeneração natural, manejo ou recuperação de áreas degradadas. Nesse estudo analisou-se a influência das altas temperaturas e do armazenamento na germinação de espécies nativas dos Campos Sulinos (Eupatorium tanacetifolium, Vernonia flexuosa, Schlechtendalia luzulifolia e Desmanthus tatuhyensis). Sementes armazenadas por 36 meses foram submetidas a cinco tratamentos (choques térmicos de 60oC, 80oC e 100oC por 1 minuto e controles sob luz e escuro) e mantidas por 60 dias em câmaras de germinação (12/12h, 20/30°C), tendo sido realizado o teste de tetrazólio naquelas não germinadas. Sementes de todas as espécies apresentaram baixa germinabilidade, não havendo diferença significativa entre os tratamentos e controles e choques de temperatura. O fato dos choques térmicos não interferirem na germinação indica que estas espécies são adaptadas ao fogo. O armazenamento reduziu o porcentual de germinação de E. tanacetifolium e de S. luzulifolia, espécie que se encontra na lista de espécies ameaçadas de extinção. As outras espécies não foram afetadas pelo tempo de estocagem, indicando que podem ser armazenadas nas condições do experimento. As espécies apresentaram diferentes tempos médios necessários para a germinação e índice de velocidade de germinação, com pouca influência dos tratamentos nesses parâmetros.Item Exploring Al, Mn and Fe phytoextraction in 27 ferruginous rockyoutcrops plant species.(2017) Schettini, Antonella Tonidandel; Leite, Mariangela Garcia Praça; Messias, Maria Cristina Teixeira Braga; Gauthier, Arnaud; Li, Haixiao; Kozovits, Alessandra RodriguesWorldwide, substrates naturally rich in Al, Fe and Mn are the subject of mining, generating degradation oflarge areas and producing wastes with high pollution potential for water resources, soil and atmosphere,causing harm to human health and ecosystems. The present study investigated the total and phytoavail-able concentration of these elements in soils and leaves of 27 native plant species from ferruginous rockyoutcrops, finding values above the toxic limits described in literature and environmental legislation.Foliar levels of metals varied widely among species, demonstrating different phytoextraction or exclu-sion potentials, which were not explained by the total concentration of elements or available soil fractions.Although most species are not considered hyperaccumulators, the results indicate the existence of speciesrelated to sites of greater availability of certain metals or that can modify soil quality through their dif-ferent phytoextraction skills, with potential future uses in decontamination, stabilization, phytominingand ecological restoration projects.Item Plant defense against leaf herbivory based on metal accumulation : examples from a tropical high altitude ecosystem.(2016) Ribeiro, Sérvio Pontes; Londe, Vinícius; Bueno, Amauri Pires; Barbosa, Juliana Silveira; Corrêa, Tatiana Lopez; Soeltl, Tatiana Maria; Maia, Márcia; Pinto, Victor D.; Dueli, Grazieli de França; Sousa, Hildeberto Caldas de; Kozovits, Alessandra Rodrigues; Nalini Júnior, Hermínio AriasSpecies that evolved in high-altitude grasslands, where soils are dystrophic and metal rich, developed adaptations for these extreme conditions, such as metal accumulation and sclerophyllous leaves, and these adaptations may secondarily affect insect herbivory activity. The present study investigates the hypothesis that costs related to accumulation of certain metals may be evolutionarily compensated for by decreasing leaf herbivory in some plant species from rupestrian fields. Studies were conducted in different locations at the Ferriferous Quadrangle, a metal-rich region in south-east Brazil, with four species adapted to high-altitude grasslands: Eremanthus erythropappus, Eremanthus incanus, Lychnophora ericoides and Byrsonima variabilis. Sample design varied according to population sizes and spatial distribution of individuals. We found that concentrations of manganese (Mn) and iron (Fe) significantly reduced the herbivory in the leaves of E. erythroppapus and E. incanus, whereas aluminum (Al) reduced herbivory in L. ericoides, and Mn affected negatively the herbivory in B. variabilis. These results support the hypothesis that metal-accumulating plants, as a response to the harsh environment in which they evolved, are protected against foliar damage caused by insect herbivores in rupestrian fields.