South Africa is one of the most important mining countries in the world, hosting the world's largest reserves of platinum group metals (PGMs). Even though mining is clearly an important activity in South Africa, contributing approximately US$ 7.4 billion annually to the countries' gross domestic product (GDP), the costs to the environment are not insignificant. One of the most severe environmental aspects associated with mining is the storage of mineral waste on tailings storage facilities due to their impacts on air quality, ground water quality, aesthetics and land use. It is also unknown whether the environmental effects of tailings storage facilities increase or decrease over time. The aim of this study was to determine the ecotoxicity of platinum tailings storage facilities of different ages by means of soil physical and chemical analysis, earthworm ecotoxicological studies, dehydrogenase activity and soil mesofauna studies. Samples were obtained from three platinum tailings storage facilities of different ages of which two were already rehabilitated while the third was still operational at the time this study was performed. The latter was used as a negative control for the purpose of the study. Soil samples were physically and chemically analysed. Earthworm ecotoxicological studies were conducted to determine changes in biomass, reproduction, mortality, neutral red retention times and tissue metal concentrations. Dehydrogenase activity was determined before the introduction of earthworms and manure, after introductions of manure and after introductions of earthworms and manure. Soil mesofauna were extracted and identified in order to determine species richness, diversity, abundance and functional grouping. Soil chemical analysis indicated that concentrations of certain heavy metals, especially chrome (Cr), present in platinum tailings materials could have a potential effect on microorganisms, microbial processes and earthworms. Earthworm ecotoxicological results indicated that earthworms that bioaccumulated higher levels of heavy metals showed poor hatchability of cocoons. Dehydrogenase activity indicated that earthworms play a significant role in increasing the number and biomass of soil microbes because significant increases in dehydrogenase activity were noticed after the addition of earthworms to platinum tailings materials. Results from the earthworm ecotoxicological studies, dehydrogenase activity, and soil mesofauna composition indicated that environmental impacts of tailings storage facilities did not increase with age, but is more likely to be an indication of the rehabilitation measures administered to the different tailings storage facilities. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2009.

South Africa is one of the most important mining countries in the world, hosting the world's largest reserves of platinum group metals (PGMs). Even though mining is clearly an important activity in South Africa, contributing approximately US$ 7.4 billion annually to the countries' gross domestic product (GDP), the costs to the environment are not insignificant. One of the most severe environmental aspects associated with mining is the storage of mineral waste on tailings storage facilities due to their impacts on air quality, ground water quality, aesthetics and land use. It is also unknown whether the environmental effects of tailings storage facilities increase or decrease over time. The aim of this study was to determine the ecotoxicity of platinum tailings storage facilities of different ages by means of soil physical and chemical analysis, earthworm ecotoxicological studies, dehydrogenase activity and soil mesofauna studies. Samples were obtained from three platinum tailings storage facilities of different ages of which two were already rehabilitated while the third was still operational at the time this study was performed. The latter was used as a negative control for the purpose of the study. Soil samples were physically and chemically analysed. Earthworm ecotoxicological studies were conducted to determine changes in biomass, reproduction, mortality, neutral red retention times and tissue metal concentrations. Dehydrogenase activity was determined before the introduction of earthworms and manure, after introductions of manure and after introductions of earthworms and manure. Soil mesofauna were extracted and identified in order to determine species richness, diversity, abundance and functional grouping. Soil chemical analysis indicated that concentrations of certain heavy metals, especially chrome (Cr), present in platinum tailings materials could have a potential effect on microorganisms, microbial processes and earthworms. Earthworm ecotoxicological results indicated that earthworms that bioaccumulated higher levels of heavy metals showed poor hatchability of cocoons. Dehydrogenase activity indicated that earthworms play a significant role in increasing the number and biomass of soil microbes because significant increases in dehydrogenase activity were noticed after the addition of earthworms to platinum tailings materials. Results from the earthworm ecotoxicological studies, dehydrogenase activity, and soil mesofauna composition indicated that environmental impacts of tailings storage facilities did not increase with age, but is more likely to be an indication of the rehabilitation measures administered to the different tailings storage facilities. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2009.

South Africa is one of the most important mining countries in the world, hosting the world's largest reserves of platinum group metals (PGMs). Even though mining is clearly an important activity in South Africa, contributing approximately US$ 7.4 billion annually to the countries' gross domestic product (GDP), the costs to the environment are not insignificant. One of the most severe environmental aspects associated with mining is the storage of mineral waste on tailings storage facilities due to their impacts on air quality, ground water quality, aesthetics and land use. It is also unknown whether the environmental effects of tailings storage facilities increase or decrease over time. The aim of this study was to determine the ecotoxicity of platinum tailings storage facilities of different ages by means of soil physical and chemical analysis, earthworm ecotoxicological studies, dehydrogenase activity and soil mesofauna studies. Samples were obtained from three platinum tailings storage facilities of different ages of which two were already rehabilitated while the third was still operational at the time this study was performed. The latter was used as a negative control for the purpose of the study. Soil samples were physically and chemically analysed. Earthworm ecotoxicological studies were conducted to determine changes in biomass, reproduction, mortality, neutral red retention times and tissue metal concentrations. Dehydrogenase activity was determined before the introduction of earthworms and manure, after introductions of manure and after introductions of earthworms and manure. Soil mesofauna were extracted and identified in order to determine species richness, diversity, abundance and functional grouping. Soil chemical analysis indicated that concentrations of certain heavy metals, especially chrome (Cr), present in platinum tailings materials could have a potential effect on microorganisms, microbial processes and earthworms. Earthworm ecotoxicological results indicated that earthworms that bioaccumulated higher levels of heavy metals showed poor hatchability of cocoons. Dehydrogenase activity indicated that earthworms play a significant role in increasing the number and biomass of soil microbes because significant increases in dehydrogenase activity were noticed after the addition of earthworms to platinum tailings materials. Results from the earthworm ecotoxicological studies, dehydrogenase activity, and soil mesofauna composition indicated that environmental impacts of tailings storage facilities did not increase with age, but is more likely to be an indication of the rehabilitation measures administered to the different tailings storage facilities. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2009.

Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2018-02-08T11:38:37Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese de Doutorado - Ryan Noremberg Schubert.pdf: 1844986 bytes, checksum: 9552c9e13ac46ed98daf9680b0e24734 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2018-02-16T11:17:54Z (GMT) No. of bitstreams: 2 Tese de Doutorado - Ryan Noremberg Schubert.pdf: 1844986 bytes, checksum: 9552c9e13ac46ed98daf9680b0e24734 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-02-16T11:17:54Z (GMT). No. of bitstreams: 2 Tese de Doutorado - Ryan Noremberg Schubert.pdf: 1844986 bytes, checksum: 9552c9e13ac46ed98daf9680b0e24734 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-09-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / O objetivo deste trabalho foi estudar a fauna edáfica ocorrente no processo de vermicompostagem dos resíduos de erva-mate, borra de café, estercos bovino, equino e ovino, assim como, analisar química e fisicamente estes materiais. Estes substratos foram armazenados em vasos plásticos com capacidade de 10 litros, em bancadas horizontais em laboratório, utilizando-se um delineamento inteiramente casualizado, com cinco repetições, onde, após um período de estabilização, inoculou-se 150 minhocas da Califórnia (Eisenia foetida) em cada tratamento. Como ferramenta de análise dos dados, utilizou-se o programa estatístico DivEs® para o cálculo dos índices ecológicos de diversidade, dominância, equitabilidade e riqueza de espécies, utilizados para análises da mesofauna edáfica. Foram realizadas avaliações de macronutrientes, relação C/N, carbono orgânico, pH, densidade, umidade, contagem edáfica da mesofauna (ácaros e colêmbolos), da macrofauna (minhocas e casulos) e microorganismos (fungos totais, bactérias degradadoras de celulose e bactérias diazotróficas) além da respiração microbiana. Os resíduos estudados apresentaram resultados distintos entre si. Foi verificado uma superioridade numérica da mesofauna edáfica nos resíduos vegetais quando comparado com os de origem animal, havendo um predomínio de colêmbolos em todos os tratamentos avaliados (95%). Com relação a macrofauna, observou-se um maior número de casulos (n = 323) e minhocas (n = 236) ao final do processo de vermicompostagem, no esterco ovino. Ao longo da execução do experimento notou-se que somente no tratamento esterco bovino houve uma diminuição no desenvolvimento de bactérias degradadoras de celulose (de 6,6 x 1011 para 2,3 x 109 ), já para as bactérias diazotróficas, apenas no tratamento esterco equino ocorreu um aumento na sua população (de 6,0 x 103 para 9,5 x 107 ). Fungos totais mantiveram uma distribuição homogênea no decorrer das avaliações em todas as unidades experimentais. Na totalidade das amostras houve uma redução da respiração microbiana durante o processo de vermicompostagem, devido a maturação dos resíduos orgânicos. Observou-se uma diminuição da relação C/N, com destaque para os resíduos vegetais que apresentaram os maiores valores da mesma, entretanto, nestes resíduos foram verificados as menores concentrações dos macronutrientes P, K e Mg. Com exceção do esterco equino, o pH ajustou-se para valores recomendáveis ao final do experimento em todos os substratos. Os índices ecológicos de diversidade e equitabilidade mostraram um predomínio de organismos no esterco ovino. Diante dos resultados obtidos neste estudo, pode-se sugerir a utilização destes resíduos para a vermicompostagem, e recomendar o uso de seus vermicompostos como adubo orgânico com precauções. / The objective of this work was to study the edaphic fauna occurring in the vermicompost process of the residues of herb-checkmate, coffee drag, bovine, equine and ovine manure, as well as to analyze chemically and physically these materials. These substrates were stored in 10 liter plastic plots in horizontal laboratory benches, using a completely randomized design with five replications, where, after a stabilization period, 150 California worms (Eisenia foetida) in each treatment. As a tool for data analysis, the statistical software DivEs® were used to calculate the ecological indexes of diversity, dominance, equitability and species richness, used for analysis of the edaphic mesofauna. In this study different evaluations were made such as: macronutrients, C/N ratio, organic carbon, pH, density, humidity, counting of the edaphic mesofauna (mites and collembolans), macrofauna (worms and cocoons) and microorganisms (total fungi, cellulose-degrading bacteria and diazotrophic bacteria) and microbial respiration. The residues studied presented different results among themselves. It was verified a numerical superiority of the edaphic mesofauna in the vegetal residues when compared with the ones of animal origin, being a predominance of collembolans in all the evaluated treatments (n = 121864). With regard to macrofauna, a larger number of cocoons (n = 323) and earthworms (n = 236) were observed at the end of the vermicompost process in ovine manure. During the execution of the experiment it was noticed that only in the bovine manure treatment there was a decrease in the development of cellulose degrading bacteria (from 6.6 x 1011 to 2.3 x 109 ), already for the diazotrophic bacteria, only in the treatment equine manure occurred an increase in its population (from 6.0 x 103 to 9.5 x 107 ). Total fungi maintained a homogeneous distribution throughout the evaluations in all the experimental units. In all the samples there was a reduction of the microbial respiration during the vermicompost process due to the maturation of the organic residues. It was observed a decrease in the C/N ratio, with emphasis on the vegetable residues that presented the highest values of the same, however, in these residues were verified the lowest concentrations of the macronutrients P, K and Mg. With the exception of equine manure, the pH adjusted to values recommended at the end of the experiment on all substrates. The ecological indexes of diversity and equitability showed a predominance of organisms in ovine manure. Considering the results obtained in this study, we can suggest the use of these residues for vermicomposting, and recommend the use of their vermicompost as an organic fertilizer with the precautions.

L'objectif de cette thèse est d'étudier le processus de décomposition des litières en région méditerranéenne et comment ce processus pouvait être affecté par le changement climatique. Dans un premier temps, nous avons abordé le rôle de la qualité et de la diversité des litières sur le processus de décomposition dans deux écosystèmes typiques de la région méditerranéenne française : la forêt à chêne et la garrigue à chêne kermès. Dans un second temps, nous avons étudié l'impact du changement climatique (via un stress hydrique aggravé) sur le processus de décomposition.Nous avons montré des effets de la diversité des litières sur le processus de décomposition et sur la structure des communautés d'organismes décomposeurs. Dans la forêt, les espèces compagnes de Q. pubescens favorisent la diversité et l'abondance des communautés d'organismes décomposeurs ainsi qu'un processus de décomposition plus efficace. A l'opposé, dans la garrigue, c'est l'espèce structurante qui favorise la décomposition et les décomposeurs.En ce qui concerne l'évolution de la relation diversité des litières - processus de décomposition dans un contexte de changement climatique, on observe une forte diminution des interactions synergiques en forêt (excepté à forte diversité végétale), alors qu'à l'opposé, cela entraine, en garrigue, une meilleure complémentarité entre les espèces avec une forte augmentation des effets synergiques.Mes résultats suggèrent que la diversité des communautés végétales joue un rôle important sur le processus de décomposition et mettent en avant que le maintien de cette diversité semble nécessaire dans un contexte de changement climatique. / L'objectif de cette thèse est d'étudier le processus de décomposition des litières en région méditerranéenne et comment ce processus pouvait être affecté par le changement climatique. Dans un premier temps, nous avons abordé le rôle de la qualité et de la diversité des litières sur le processus de décomposition dans deux écosystèmes typiques de la région méditerranéenne française : la forêt à chêne et la garrigue à chêne kermès. Dans un second temps, nous avons étudié l'impact du changement climatique (via un stress hydrique aggravé) sur le processus de décomposition.Nous avons montré des effets de la diversité des litières sur le processus de décomposition et sur la structure des communautés d'organismes décomposeurs. Dans la forêt, les espèces compagnes de Q. pubescens favorisent la diversité et l'abondance des communautés d'organismes décomposeurs ainsi qu'un processus de décomposition plus efficace. A l'opposé, dans la garrigue, c'est l'espèce structurante qui favorise la décomposition et les décomposeurs.En ce qui concerne l'évolution de la relation diversité des litières - processus de décomposition dans un contexte de changement climatique, on observe une forte diminution des interactions synergiques en forêt (excepté à forte diversité végétale), alors qu'à l'opposé, cela entraine, en garrigue, une meilleure complémentarité entre les espèces avec une forte augmentation des effets synergiques.Mes résultats suggèrent que la diversité des communautés végétales joue un rôle important sur le processus de décomposition et mettent en avant que le maintien de cette diversité semble nécessaire dans un contexte de changement climatique.

Submitted by Katiane Souza (katyane.souza@gmail.com) on 2016-05-12T14:09:26Z No. of bitstreams: 1 arquivototal.pdf: 1764591 bytes, checksum: 8c79fbd17f4301ebf5fb2c42a5a71c72 (MD5) / Made available in DSpace on 2016-05-12T14:09:26Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1764591 bytes, checksum: 8c79fbd17f4301ebf5fb2c42a5a71c72 (MD5) Previous issue date: 2006-03-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Nutrient cycling is fundamental to forest maintenance, and involves the deposition of organic material, its decomposition and nutrient release for reabsorption by superior plants. These processes are regulated by biotic and abiotic factors that determine the environmental sustainability. This study had the objectives to determine the monthly litter production and the time necessary to the accumulated litter to disappear, characterize the process of decomposition, evaluate the microbial activity and the effect of climatic and soil conditions on it, determine the fluctuations of the microorganisms and mesofauna communities in a Caatinga forest site, and, finally, analyze liter quality in order to identify the different phases of the process of organic matter decomposition and nutrient enrichment. Field work was carried out at the RPPN of the Fazenda Tamanduá, located in Santa Terezinha (PB), from October 2003 to September 2004 (period 1 = P1) and from October 2004 to September 2005 (period 2 = P2) in seven transects systematically located in the RPPN area. Litter production were estimated from monthly litter collection from 20 1mx1m collector boxes randomly distributes in the transects. The collected litter was fractioned into leaves, stems, reproductive structures and miscellany, and then dried and weighed. Every three months the deposited litter on the soil was collected from 0,5mx0,5m frames, dried and weighed, to calculate the decomposition factor (K) and the time required to 50 and 95% of litter decomposition. The rate of litter decomposition was estimated in nylon bags with 30g of dried litter. These 480 nylon bags were divided equitably and placed around the 20 collector boxes. Every month, one nylon bag from each collector bag was recovered from the field and the litter inside was taken out, cleaned and weighed to determine its weight loss. Diurnal and nocturnal microbial activity was measured by means of soil respiration. Macronutrients composition of the deposited litter and in the litter inside the nylon bag was determined. Litter production during P1 and P2 was 1290.9 kg ha-1 and 1947.5 kg ha-1, respectively, totaling 3238.5 kg ha-1. Leaf, stem, reproductive structure and miscellany fractions corresponded to 64.14, 23.48, 10.9 and 1.46% of total litter production, respectively. More litter deposition was observed in the beginning of the dry season. The values of the coefficient of litter decomposition were 1.1 and 1.4 for P1 and P2, respectively, and mean a fast nutrient transfer from litter to soil. The time required to 50 and 95% litter decomposition was 229.9 and 996.4 days, respectively, in P1, and 178.8 and 770.1 days, respectively, in P2. Initial litter weight loss in nylon bags was fast due to the degradation of labile composts by microorganisms, and decreased afterward due to the more resistant and more lignified materials of the remaining litter. Fungi population was larger than the bacteria population, favored by soil water availability. Mesofauna was mainly represented by Diptera’s 67.24% of the total number of counted mesofauna individuals or of the total biomass of mesofauna individuals and Acarine’s (53.49%), in P1 and P2, respectively. The low values of Shannon (0.38) and Pielou (0.15) indexes denoted the distribution heterogeneity of the mesofauna representatives. The order of macronutrient concentrations in the accumulated litter was as follow: N > Ca > S > K > Mg > P. Litter P content was higher than the expected for dry tropical forests. / A ciclagem de nutrientes, fundamental para a manutenção das florestas, envolve desde a deposição de material orgânico, sua decomposição e disponibilidade de nutrientes para os vegetais superiores. Todos esse processos são regulados por fatores bióticos e abióticos que determinam a sustentabilidade do ambiente. Este trabalho teve como objetivos determinar a produção mensal de serapilheira e o tempo necessário para o desaparecimento da serapilheira acumulada; caracterizar o processo de decomposição; avaliar a atividade microbiana e a influência das condições edafoclimáticas durante esse processo; conhecer as flutuações das comunidades de microrganismos e da mesofauna do solo em área de caatinga e, por último, analisar a qualidade da serapilheira a fim de identificar as diferentes fases do processo de decomposição e concentração de nutrientes. O trabalho foi desenvolvido na RPPN pertencente à Fazenda Tamanduá, localizada no município de Santa Terezinha (PB), durante dois anos, sendo o período 1 compreendido de outubro/2003 a setembro/2004 e o período 2 compreendido de outubro/2004 a setembro/2005. Foram demarcados sete transectos, onde foram realizadas todas as avaliações. Para a produção da serapilheira, foram distribuídas 20 caixas coletoras de 1m x 1m, sendo mensalmente coletado todo o material precipitado, que foi separado nas seguintes frações: folhas, galhos, estruturas reprodutivas e miscelânea; depois foi seco em estufa e pesado. A cada três meses foi coletada a serapilheira acumulada no solo, utilizando-se uma moldura metálica de 0,50 m x 0,50 m. Todo o material acumulado na moldura foi retirado, seco em estufa e pesado, calculando-se assim o fator de decomposição K e o tempo necessário para decompor 50% e 95% da serapilheira. Na avaliação da taxa de decomposição da serapilheira, utilizou-se sacola de náilon contendo cada uma 30g de serapilheira previamente seca. Próximo de cada caixa coletora foram distribuídas 24 sacolas de náilon contendo serapilheira, totalizando 480 sacolas. Mensalmente foram coletadas 20 sacolas, sendo o material retirado, limpo e pesado para avaliar a perda de peso em relação ao inicial. Paralelamente, avaliou-se no campo, a atividade microbiana, medida pela respiração edáfica, nos turnos diurno e noturno. Determinou-se também a qualidade química da serapilheira depositada e a que foi decomposta nas sacolas de náilon, quanto à concentração dos macronutrientes. A produção de serapilheira durante o período 1 de estudo foi de 1290,95 kg ha-1 e 1947,56 kg ha-1 no período 2, totalizando 3.238,51 kg ha-1, sendo a fração folhas predominante na serapilheira devolvida ao solo com 64,14%, seguida da fração galhos (23,48%), estruturas reprodutivas (10,92%) e miscelânea (1,46%). A maior deposição ocorreu no início da estação seca, caracterizando a sazonalidade. Os coeficientes de decomposição (K) de 1,1 para o período 1 e, 1,4 para o período 2, indicam uma transferência mais rápida dos nutrientes contidos na serapilheira para o solo. O tempo necessário para decompor 50% e 95% da serapilheira foi de 229,9 dias e 996,4 dias, respectivamente, período 1. No período 2, o tempo de meia vida foi de 178,8 e 770,15 dias para decompor 95%.A maior perda de peso da serapilheira acondicionada nas sacolas de náilon ocorreram no início do período de exposição, resultado da degradação dos compostos lábeis pelos microrganismos, sendo a velocidade do processo diminuída ao longo do tempo, devido a permanência das partes mais resistentes e lignificadas da serapilheira. Quanto a microbiota, a maior população foi de fungos, em relação à de bactérias, estimulado, principalmente, pelas condições favoráveis na disponibilidade hídrica do solo. Os grupos predominantes da mesofauna foram Díptera com 67,24% no período 1 e Acarine com 53,49% no período 2. Os baixos valores nos índices de Shannon (0,38) e de Pielou (0,15), indicaram uma baixa uniformidade na distribuição dos indivíduos. Quanto à composição química da serapilheira, a serapilheira depositada apresentou concentração de nutrientes na seguinte ordem: N > Ca > > S > K > Mg > P, sendo os teores de P encontrados na serapilheira considerados elevados para florestas tropicais secas.

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