Navegando por Autor "Diniz, Adriana Pedrosa"
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Item Fitoextração de metais de espécies florestais nativas plantadas sobre rejeito de mineração de ferro.(2018) Diniz, Adriana Pedrosa; Kozovits, Alessandra Rodrigues; Lana, Cristiano de Carvalho; Leite, Mariangela Garcia Praça; Afonso, Robson José de Cássia Franco; França, Marcel Giovanni Costa; Kozovits, Alessandra RodriguesO Brasil presenciou em novembro de 2015 um dos seus maiores impactos ambientais ocasionado pelo rompimento de uma das barragens de rejeitos de minério de ferro da empresa Samarco. Cerca de 43 milhões de m3 de rejeito foram depositados na bacia do Rio Doce, exigindo a adoção de medidas para a mitigação da contaminação ambiental e recuperação das áreas afetadas, incluindo esforços de revegetação. Grande parte das formações vegetacionais atingidas é composta por espécies da Mata Atlântica e pouco se sabe sobre o desenvolvimento dessas espécies em rejeitos de minério de ferro. No presente estudo, avaliou-se o estado nutricional de plantas jovens de espécies nativas cultivadas sobre tal rejeito as margens do rio Gualaxo. A análise dos elementos no tecido foliar das plantas antes e após um ano de plantio sobre o rejeito foi realizada por meio da técnica de Laser Ablation acoplado a espectrometria de massa (LA-ICP-MS). Além da comparação das concentrações desses elementos no tecido foliar nas espécies antes e após o plantio, o presente estudo visou também comparar a efetividade da metodologia desenvolvida em dois tipos de espectrômetros: quadrupolo (QMS)e campo de setor magnético (SF). Constatou-se que o LA-SF-ICP-MS atende melhor aos quesitos precisão e acurácia; entretanto, a técnica ainda sofre limitações principalmente em relação a falta de um padrão que cubra a extensão de analitos da amostra. Nesse sentido, o uso de folhas pulverizadas e prensadas de candeia foi apresentado como um padrão potencial para ser utilizado no ajuste da metodologia. As concentrações médias de Mg, Ca e Zn nas folhas foram menores um ano após o plantio, o que pode estar relacionado a baixa concentração desses nutrientes no substratos (Mg e Zn) e também a alta concentração de íons de Mn. As espécies mais vulneráveis a contaminação foram: Eugenia pyriformis, Zeyheria tuberculosa, Copaifera langsdorfii e Apuleia leiocarpa. Já Dendropanax cuneatus, Cariniana estrellensis, Platypodium elegans e Lafoensia pacari apresentam potencial para o uso na restauração dessas áreas por apresentaram o mesmo padrão de concentração de elementos antes e após plantio.Item Growing Periandra mediterranea on post-mining substrate : native Fabaceae with potential for revegetation of degraded rupestrian grasslands in Brazil.(2018) Figueiredo, Maurílio Assis; Diniz, Adriana Pedrosa; Abreu, Adriana Trópia de; Messias, Maria Cristina Teixeira Braga; Kozovits, Alessandra RodriguesRecovery of degraded areas of rupestrian grasslands is hampered mainly by the limited knowledge regarding substrate management and the biology of native species suitable for revegetation of these areas. Th e aim of our study was to examine the establishment and growth of Periandra mediterranea in diff erent textures of lateritic substrate from a mining-degraded area. Th e growth of P. mediterranea was evaluated using fi ne and coarse laterite, both with and without the addition of topsoil. Survival, dry biomass, content of chemical elements and nodulation were evaluated in ten individuals per treatment sixteen months after planting. Although the substrate has low nutrient content, yet high metal concentrations, all plants survived. Plants growing on coarse laterite had 140 % greater biomass than those growing on fi ne laterite. Th e addition of topsoil increased biomass in coarse and fi ne laterite by 46 and 151 %, respectively, and doubled the number of nodulated plants, regardless of grain size. Th e biomass accumulation of P. mediterranea to a dystrophic substrate revealed its potential for use in the revegetation of degraded areas of rupestrian grasslands. Furthermore, the addition of topsoil facilitated the association of P. mediterranea with nitrogen-fi xing bacteria, and increased its growth and capacity to improve substrate fertility.Item Oxidant-antioxidant balance and tolerance against oxidative stress in pioneer and non-pioneer tree species from the remaining Atlantic Forest.(2018) Esposito, Marisia Pannia; Nakazato, Ricardo Keiichi; Pedroso, Andrea Nunes Vaz; Lima, Marcos Enoque Leite; Figueiredo, Maurílio Assis; Diniz, Adriana Pedrosa; Kozovits, Alessandra Rodrigues; Domingos, MarisaThe extensive land occupation in Southeast Brazil has resulted in climatic disturbances and environmental contamination by air pollutants, threatening the Atlantic forest remnants that still exist in that region. Based on previous results, we assumed that pioneer tree species are potentially more tolerant against environmental oxidative stress than non-pioneer tree species from that Brazilian biome. We also assumed that reactive oxygen species (ROS) are accumulated in higher proportions in leaves of non-pioneer trees, resulting in changes in the oxidant-antioxidant balance and inmore severe oxidative damage at the cellular level than in the leaves of pioneer trees. We tested these hypotheses by establishing the relationship between oxidants (ROS), changes in key antioxidants (among enzymatic and non-enzymatic compounds) and in a lipid peroxidation derivative in their leaves, aswell as between ROS accumulation and oscillations in environmental stressors, thus permitting to discuss comparatively for the first time the oxidant-antioxidant balance and the tolerance capacity of tree species of the Atlantic Forest in SE Brazil.We confirmed that the non-pioneer tree species accumulated higher amounts of superoxide and hydrogen peroxide in palisade parenchyma and epidermis, showing a less effective antioxidant metabolism than the pioneer species. However, the non-pioneer species showed differing capacities to compensate the oxidative stress in both years of study, which appeared to be associated with the level of ROS accumulation, which was evidently higher in 2015 than in 2016. We also applied exploratory multivariate statistics, which revealed that the oscillations in these biochemical leaf responses in both functional groups coincided with the oscillations in both climatic conditions and air pollutants, seemingly showing that they had acclimated already carried out, including Bussotti (2008) that concluded that early successional species in Mediterranean forests have a lower tolerance against oxidative stress than late secondary species and Favaretto et al. (2011) that classified native tree species of the Atlantic Forest into two major functional groups based on their tolerance against solar radiation exposure. Brandão et al. (2017) assumed that pioneer species from disturbed remnants of the Atlantic Forest in São Paulo (Brazil) are potentially more tolerant against oxidative stress than non-pioneer species based on the levels of antioxidants. However, this hypothesis would be definitely confirmed only if the lower antioxidative capacity in nonpioneer trees occurred in parallel with increased levels of ROS in the leaves, resulting in loss of the oxidant-antioxidant equilibrium, severe oxidative damage at the cellular level and consequently decreased tolerance against oxidative stress. The present study brought a new contribution to this broader issue, permitting to discuss comparatively the oxidant-antioxidant balance and the tolerance capacity of pioneer and non-pioneer tree species of Atlantic Forest remnants affected by multiple environmental stressors in SE Brazil.We achieved this goal by establishing the relationship between oxidants (ROS), changes in key antioxidants (among enzymatic and non-enzymatic compounds) and in a lipid peroxidation derivative in their leaves, as well as between ROS accumulation and oscillations in environmental stressors.Item Propagation and establishment of rupestrian grassland grasses for restoration of degraded areas by mining.(2018) Figueiredo, Maurílio Assis; Diniz, Adriana Pedrosa; Messias, Maria Cristina Teixeira Braga; Kozovits, Alessandra RodriguesInvestigations on the propagation and establishment of native grasses of rupestrian grassland on degraded substrates are essential to enable their use in the restoration of degraded areas, thus reducing the use of exotic species. This study aimed to evaluate the sexual and asexual propagation, establishment and growth of Axonopus laxiflorus (Trin.) Chase and Sporobolus metallicolus Longhi-Wagner & Boechat, two native grasses from rupestrian grassland developed on laterite substrate of an area degraded by bauxite mining. In greenhouse experiments, A. laxiflorus was propagated by tillers and S. metallicolus by seeds and tillers. Both species were also evaluated for germination in a germination chamber on the treatments: control, addition of potassium nitrate and heating at 80 °C for 2 min. In these evaluations, success of S. metallicolus germination was between 77 and 90%, without significative difference among treatments, whereas A. laxiflorus did not germinate. In the laterite substrate, S. metallicolous, propagated by seeds, showed 29% of survival, whereas in the vegetative propagation all plants of the two species survived. Eight months after starting the tiller experiment, S. metallicolus and A. laxiflorus presented a biomass increase of 239 and 75%, respectively. Although A. laxiflorus showed root biomass approximately seven times higher than S. metallicolus, the two species presented similar root length, that is, S. metallicolus contained more fine roots. The results show that the species can efficiently propagate vegetatively and, in the case of S. metallicolus, sexually. The success of the species in a substrate poor in nutrients and rich in Al, Fe and Mn indicates that they can be used in the restoration of areas degraded by bauxite and iron mining, which are important mining activities in Brazil.Item 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.