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1
Coulibaly, Sekou Fanta Mady. "Effets des changements de pratiques agronomiques sur la diversité des vers de terre et collemboles- conséquences sur leurs fonctions associées." Thesis, Normandie, 2018. http://www.theses.fr/2018NORMR005/document.
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Le sol est une des composantes essentielles au soutien du fonctionnement de l’écosystème. Il est lesupport de la production primaire, un habitat pour la diversité biologique et remplit de nombreux processus écologiques. Les activités anthropiques, et parmi elles, les pratiques agricoles intensives, ont conduit à des déséquilibres au sein du sol causant un fort déclin de leur biodiversité. En réponse à ces effets, de nouvelles pratiques agricoles ont été développées pour préserver les sols et les services écosystémiques qu’ils fournissent. Ces pratiques dites innovantes s’appuient principalement sur la réduction du travail du sol, une gestion intégrée des résidus de culture, l’installation d’un couvert végétal permanent ou encore l’introduction de légumineuses dans les rotations de culture. C’est dans ce contexte de mutation des pratiques agricoles que s’inscrit ce sujet de thèse qui vise à mieux comprendre les effets de l’adoption de ces gestions innovantes sur (i) la diversité des communautés de la macro- et de la mésofaune du sol et (ii) sur le fonctionnement du sol en termes de stockage ducarbone organique (source de nourriture de base), de structure du sol et de distribution de la taille des pores (milieu de vie). Au cours des différents chapitres de ce travail, nous avons mis en évidence trois actions liées à des pratiques agricoles innovantes combinant des approches expérimentales in et ex situ. L’objectif de la première action visait à étudier l’effet combiné de l’introduction de légumineuse (féverole) et de la réduction du travail du sol sur le compartiment endogé. Pour y répondre, nous avons développé une conception expérimentale empirique faite avec la combinaison des situations rencontrées dans les fermes. Nos résultats ont montré que l’interaction entre les deux pratiques innovantes n’a pas entrainé d'augmentation significative de la diversité de la faune du sol. Les fonctions microbiennes ainsi que la dynamique du carbone (C) et de l’azote (N) ne semblent pas non plus être affectées par ces pratiques. Il s’avère que les effets bénéfiques de ces pratiques innovantes ne peuvent être envisagés sans prendre en compte la manière dont elles sont mises en oeuvre à l’échelle des rotations culturales et des itinéraires techniques. Cela nous a permis de valoriser une seconde action dont l’objectif était de suivre dans les mêmes conditions pédoclimatiques et mêmes itinéraires techniques, l'effet à long terme (quatre ans) de cinq régimes de gestion différents sur les communautés de faune du sol. Les traitements comprenaient des combinaisons de différentes cultures (annuelles, vivaces), de différents taux de fertilisation azotée (ajout d'azote, azote réduit),incorporation ou élimination de résidus de culture et différentes intensités de labour (labour vs. travail superficiel). Les résultats ont montré que la réduction de l’intensité du travail du sol a favorisé la diversité des collemboles et ses groupes fonctionnels grâce à l’amélioration des conditions de l’habitat à travers l’augmentation de la biomasse microbienne de carbone (source trophique). Par ailleurs, les autres composantes de la gestion, soit la « réduction des apports d’azote » et la « restitution / exportation des résidus de culture», n’ont pas eu d’effet sur les collemboles (abondance et richesse), notamment sur ceux vivants dans le sol, qu'ils soient hémi ou euédaphiques. Toutefois, cette étude démontre que la dissemblance dans la composition des assemblages de collemboles augmente avec la différenciation temporelle des pratiques agricoles et le travail du sol est le premier facteur responsable de cette trajectoire. Cette assertion a donné lieu à une troisième action dont l’objectif était de suivre sur une saison de végétation la conversion de la perturbation mécanique résultant du travail du sol sur la résistance et résilience fonctionnelle des assemblages biotiques édaphiquesSoil is one of the essential components supporting the functioning of the ecosystem. It is the support of primary production; an habitat for biodiversity, and it fulfills many ecological processes. Human activities, including intensive agricultural practices, have led to impaired the soil causing a sharp decline in their biodiversity. In response to these effects, new agricultural practices have been developed to preserve the soils and the ecosystem services they provide. These so-called innovative practices rely mainly on the reduction of tillage, integrated management of crop residues, the installation of permanent plant cover or the introduction of legumes into crop rotations. It is in this context of changes in agricultural practices that this thesis topic lays. This thesis aims to better understand the effects of the adoption of these innovative management practices on (i) the diversity of the macro and mesofauna communities soil and (ii) soil functioning in terms of organic carbon storage (basic food source), soil structure and pore size distribution (living environment). During the different chapters of this work, we highlighted three actions related to innovative agricultural practices combining in situ and ex situ experimental approaches. The aim of the first action was to study the combined effect of the introduction of legume (faba bean) and the reduction of tillage on the endogenous compartment. To answer this question, we developed an empirical experimental design made with the combination of situations encountered on farms. Our results showed that theinteraction between the two innovative practices did not result in a significant increase in the diversity of soil fauna. Microbial functions and the dynamics of carbon (C) and nitrogen (N) also do not seem to be affected by these practices. It turns out that the beneficial effects of these innovative practices cannot be considered without taking into account how they are implemented at the scale of crop rotations and technical itineraries. This allowed us to promote a second action whose objective was to follow, under the same pedoclimatic conditions and the same technical itineraries, the long-term effect (four years) of five different management regimes on the communities of soil fauna. Treatments included combinations of different crops, different rates of nitrogen fertilization, incorporation or removal of crop residues and different plowing intensities. The results showed that the reduction of tillage intensity favored the diversity of Collembola and its functional groups by improving habitatconditions through the increase of microbial carbon biomass (trophic source). In addition, the other components of management, namely the "reduction of nitrogen inputs" and the "restitution / export of crop residues", had no effect on springtails (abundance and wealth), in particular on those living in the soil, whether hemi or euedaphic. However, this study demonstrates that the dissimilarity in the composition of Collembola assemblages increases with the temporal differentiation of agricultural practices, and tillage was the main factor responsible for this trajectory
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Krolow, Daniela da Rocha Vitória. "Estudo da macro e mesofauna do solo em um sistema de produção de base ecológica." Universidade Federal de Pelotas, 2009. http://repositorio.ufpel.edu.br/handle/ri/1161.
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Previous issue date: 2009-03-27The present work was carried through in a property of familiar agriculture of situated ecological base, in the locality Colônia Maciel, Pelotas, RS, Brazil. The objective of the work was to characterize quantitatively and qualitatively some groups of organisms to mesofauna (Acari, Collembola, Diplura and Protura) and the macrofauna (Formicidae, Larvae of Coleopter and Díptera and Isopoda) of soil in ecological system base in the culture of the grapevine, in which, received applications of Calda Bordalesa and the biofertilizer Supermagro are carried through. An area of grapevine orchard (ecological handling) and another one with native bush at two moments of collection had been studied two distinct areas. The first collect was in 03/10/2006 and second in 14/03/2007. Two methodologie of collect of soilborne of were used the Trap of Tretzel and the Funnel of Tüllgren. It was analyzed for the two areas, the two moments of collection and both the methodologies some physical parameters (temperature and humidity of the ground), chemical parameters (Carbon of the ground, H + Al, macronutrients and micronutrients) and biological parameters as: frequency and constancy of the soilborne. For both methods collected, the biggest population of organisms found in the orchard/grapevine in the first collect revealing more frequent the groups Formicidae and Diplura through the method of the Trap of Tretzel. The Acari and Formicidae groups are more frequent in the orchard/grapevine, in the two collections through the method of the funnel of Tüllgren and in the second collection the groups Acari and Collembola through the method of the Trap of Tretzel had revealed more frequent. The Acari group presented the biggest index of constancy for both the areas and collections through the method of the Funnel of Tüllgren, being that, Acari and Collembola had always revealed constant with the use of the Trap of Tretzel. The capacity of exchange of cátions presented the same values in both the collections in the orchard/grapevine not showing interference in the edafic 8 fauna. The application of bordalesa Calda intervened in the frequency of the Acaris and Collembolas groups in the soil surface. The alimentary habit of the Acari and Formicidae groups favored these organisms.
O presente trabalho foi realizado em uma propriedade de agricultura familiar de base ecológica situada no município de Pelotas, na localidade Colônia São Manuel, RS, Brasil, cujo objetivo foi caracterizar quantitativamente e qualitativamente alguns grupos de organismos pertencentes à mesofauna (Acari, Collembola, Diplura e Protura) e a macrofauna (Formicidae, Larvas de Coleóptera e de Díptera e Isopoda) do solo em um sistema de produção de base ecológica. Foram estudadas duas áreas distintas uma área de pomar de videira (manejo ecológico) e outra com mata nativa em dois momentos de coleta. A primeira coleta se deu em 03/10/2006 e a segunda em 14/03/2007. Utilizou-se duas metodologias de coleta de organismos edáficos a Armadilha de Tretzel e o Funil de Tüllgren. Analisou-se para as duas áreas, nos dois momentos de coleta e ambas as metodologias alguns parâmetros físicos (temperatura e umidade do solo), parâmetros químicos (Carbono do solo, H + Al, macronutrientes e micronutrientes). E por fim parâmetros biológicos como: freqüência e constância dos grupos faunísticos selecionados. Para ambos os métodos de coleta, a maior população de organismos encontrados no pomar/videira foi na primeira coleta mostrando-se mais freqüente os grupos Formicidae e Diplura através do método da Armadilha de Tretzel. Os grupos Acari e Formicidae são mais freqüentes no pomar/videira, nas duas coletas através do método do funil de Tüllgren e na segunda coleta mostraram-se mais freqüentes os grupos Acari e Collembola através do método da Armadilha de Tretzel. O grupo Acari apresentou o maior índice de constância para ambas as áreas e coletas através do método do Funil de Tüllgren, sendo que, Acari e Collembola mostraram-se sempre constantes com a utilização da Armadilha de Tretzel. A capacidade de troca de cátions apresentou os mesmos valores em ambas as coletas no pomar/videira não mostrando interferência na fauna 6 edáfica. A aplicação da calda bordalesa interferiu na freqüência dos grupos Acaris e Collembolas na superfície do solo. O hábito alimentar dos grupos Acari e Formicidae favoreceu esses organismos.
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Wahl, Jurie Johannes. "Soil mesofauna as bioindicators to assess environmental disturbance at a platinum mine / Jurie J. Wahl." Thesis, North-West University, 2007. http://hdl.handle.net/10394/2042.
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Machado, Julia da Silva. "Diversidade morfológica de colêmbolos (Hexapoda: Collembola) em sistemas de manejo do solo." Universidade do Estado de Santa Catarina, 2015. http://tede.udesc.br/handle/handle/2309.
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Capes
Any inappropriate soil management, cause negative environmental impact on the diversity of soil fauna. This dissertation aimed to evaluate the influence of land use systems (LUS) on the morphological diversity of springtails, as well as its relationship with physical and chemical soil attributes. Were studied five LUS on the Plateau of Santa Catarina, Brazil: native forest (F), Eucalyptus plantation (Reu), perennial pasture (P), integrated crop-livestock (ILP) and no-tillage (PD), in two different seasons (winter and summer). The evaluation was performed by installing traps of type Pitfall traps per sampling grid (3 x 3). The same points were evaluated physical and chemical soil attributes. The morphotyping of the springtails consisted in observing five characteristics and each feature has been assigned a partial value of Eco-morphological index (EMI) for Biological Quality of Soil Index (QBS) modified. The data were subjected to multivariate analysis. In winter, the LUS (F) presented the highest abundance of morphotypes due the best values of Ca/Mg ratio, total organic carbon (TOC), bioporos, micropores and soil moisture in comparison to other LUS. ILP systems and PD already correlated with the Macropores. In the summer, again the F showed the highest abundance of morphotypes, however, the greatest diversity of levels of adaptation was found in PD. In summer, the F presented related to the TOC and micropores, while ILP and PD correlated with pH, bioporos and soil density. In winter, the value of QBS was greater in F, followed by Reu, P, PD and ILP, respectively, being smaller the higher the intensification of the LUS. In the summer, the QBS values were higher in F, followed by ILP, Reu, PD and P, respectively. The separation to the level of morphotypes proved an efficient alternative to indicate the level of intensification of land use, especially in combination with other explanatory environmental variables
Todo e qualquer manejo inadequado do solo, causa impacto ambiental negativo sobre a diversidade da fauna edáfica. A presente dissertação objetivou avaliar a influência de sistemas de uso e manejo do solo (SUS) sobre a diversidade morfológica de colêmbolos, bem como sua relação com atributos físicos e químicos do solo. Foram estudados cinco SUS no Planalto Catarinense, Brasil: floresta nativa (F), reflorestamento de eucalipto (Reu), pastagem perene (P), integração lavoura-pecuária (ILP) e plantio direto (PD), em duas épocas distintas (inverno e verão). A avaliação dos colêmbolos foi realizada instalando-se armadilhas do tipo Pitfall traps em um grid amostral (3 x 3). Nos mesmos pontos foram avaliados atributos físicos e químicos do solo. A morfotipagem dos colêmbolos consistiu na observação de cinco características e para cada característica foi atribuído um valor parcial do índice ecomorfológico (EMI) para a obtenção do Índice de Qualidade do Solo (QBS) modificado. Os dados foram submetidos a análises multivariadas. No inverno, o SUS F apresentou a maior abundância de morfotipos devido a melhores valores de relação Ca/Mg, carbono orgânico total (COT), bioporos, microporos e umidade do solo em comparação aos demais SUS. Já os sistemas ILP e PD se correlacionaram com o atributo macroporos. No verão, novamente a F apresentou maior abundância de morfotipos, porém, a maior diversidade de níveis de adaptação foi encontrada em PD. No verão, a F apresentou relação com o COT e microporos, enquanto ILP e PD se correlacionaram com pH, bioporos e densidade do solo. No inverno, o valor de QBS foi maior em F, seguido por Reu, P, PD e ILP, respectivamente, sendo menor quanto maior a intensificação do SUS. Já no verão, os valores de QBS foram maiores em F, seguido por ILP, Reu, PD e P, respectivamente. A separação ao nível de morfotipos se mostrou uma eficiente alternativa para indicar o nível de intensificação de uso do solo, principalmente em conjunto com outras variáveis ambientais explicativas
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Zagatto, Maurício Rumenos Guidetti. "Mesofauna edáfica em plantios puros e mistos de Eucalyptus grandis e Acacia mangium." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-25072018-175726/.
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A mesofauna edáfica compreende pequenos invertebrados que vivem nos primeiros centímetros do solo e na serapilheira. Sabe-se que o plantio de leguminosas com espécies arbóreas não fixadoras de nitrogênio melhora a fertilidade do solo, porém não se conhece o efeito desses plantios nos invertebrados edáficos. Diante disso, objetivou-se, com este estudo, avaliar o efeito de plantios puros e mistos de Eucalyptus grandis e Acacia mangium na mesofauna edáfica e estabelecer relações da mesofauna com os atributos químicos do solo e da serapilheira e os microbiológicos do solo, a fim de se construir um novo indicador de qualidade do solo. Para tanto, em outubro de 2015 (estação seca) e março de 2016 (estação chuvosa) foram avaliados os atributos físico-químicos da serapilheira (Ca, Mg, N, P, C, C/N, C/P, Mn, Cu, Fe, Zn, umidade), microbiológicos do solo (C mic, respiração do solo e atividade da desidrogenase), a umidade do solo e a mesofauna do solo e da serapilheira (riqueza, densidade e diversidade de mesofauna). Já os atributos químicos do solo (pH, Ca, Mg, C, N, P, Al, H+Al, Na, K) foram avaliados apenas em outubro. A média dos atributos foi comparada pelo teste de Tukey a 5%, enquanto que correlações, regressões e análises multivariadas foram feitas para estabelecer relações entre a mesofauna e os atributos do solo e da serapilheira e, posteriormente, construir um indicador geral de qualidade do solo. A fauna que habita a serapilheira, os atributos microbiológicos do solo e o indicador geral de qualidade do solo apresentaram maiores valores na estação chuvosa. A umidade foi muito correlacionada com os atributos biológicos do solo e da serapilheira. Foram também constatadas diferenças entre tratamentos, sendo que na estação seca há preferência da mesofauna pelo hábitat solo, possivelmente com a prevalência de relações mutualísticas entre microrganismos e mesofauna, enquanto há uma expressiva preferência da mesofauna pela serapilheira durante a estação úmida.Soil mesofauna comprises small invertebrates that live in the first centimeters of the soil and in the litter. The consortium between leguminous trees and non-nitrogen-fixing tree species improves soil fertility, but the effect of these plantations on edaphic invertebrates is not known yet. Thus, we aimed at evaluating the effect of pure and mixed plantation of Eucalyptus grandis and Acacia mangium on the invertebrates that inhabit the soil and litter. We looked for correlations between those plantations, soil and litter chemical attributes and soil microbiological attributes to create a general indicator of soil quality in Acacia mangium (AC), Eucalyptus grandis (EU) and mixed plantations of Acacia and Eucalyptus (M). The chemical litter attributes evaluated were Ca, Mg, N, P, C, C/N, C/P, Mn, Cu, Fe, Zn, besides soil and litter moisture, soil microbiology (microbial carbon, soil respiration and dehydrogenase activity) and soil and litter mesofauna (richness, density and diversity) in two seasons: October 2015 (dry season) and March 2016 (rainy season). Soil chemical analyses (pH, Ca, Mg, C, N, P, Al, H+Al, Na, and K) were from samples collected in October. We made comparisons of the means between forest systems, and established a general indicator of soil quality based on regressions and multivariate analyses, to identify correlations between mesofaunaand chemical and microbiological attributes. Litter mesofauna, microbial activity and the general indicator of soil quality presented much higher values in the rainy season than in the dry season. Moisture correlated positively with most of the soil and litter biological attributes. There were few differences between the forest systems; although we observed a clear mesofauna preference for soil as habitat in the dry season, possibly linked to the prevailance of mutualistic interactions between soil mesofauna and microorganisms, while the mesofauna showed great preference for the litter as habitat during the moist season.
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Krolow, Ivan Renato Cardoso. "Efeito de fertilizantes mineral, organomineral e orgânico sobre a macrofauna e mesofauna do solo." Universidade Federal de Pelotas, 2011. http://repositorio.ufpel.edu.br/handle/ri/2431.
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Previous issue date: 2011-04-15The study was performed on a rural property in the locality the Hidraulica city of Capão do Leão - Rio Grande do Sul, Brazil, to evaluate the influence of mineral fertilizers, organo-mineral and organic on macrofauna and mesofauna the soil. We used the following succession crops: Zea mays L.-forage Consortium (Trifolium repens L., Trifolium pratense L., Lotus corniculatus L. and Lolium multiflorum Lam), Sorghum bicolor L., Brassica napus L., Panicum maximum-Lolium multiflorum Lam, Helianthus annuus L.-Triticum aestivum L. Investigated the following treatments: T1-Control, T2-fertilizer mineral , T3- organo-mineral fertilizer, T4-compost fertilizer and T5-organic fertilizer turkey litter. The variables were: precipitation, soil properties (pHágua, pHSMP, electrical conductivity, organic carbon, nitrogen, carbon / nitrogen, phosphorus, potassium, calcium, magnesium, iron, aluminum, sodium, manganese, copper and zinc), attributes Soil physical (moisture and temperature), agronomic responses (yield and biomass) and soil macrofauna and mesofauna. Sowing of summer species occurred in December 2007, while those of winter, in May 2008. Grain crops were harvested at the end of their cycle, while forage in summer and winter amounted to seven six cuts successive, respectively. The results of soil temperature, soil moisture, yield, agronomic and representatives of the fauna were subjected to analysis of variance, mean test (Duncan 5%) probability. The fauna found was also analyzed for density, richness, relative frequency, classification by Abundance, diversity index and evenness index. Results related to soil fauna, macronutrients, micronutrients and soil conductivity were also submitted to multivariate analysis. The Fertilizers compost and organic-mineral was associated more effectively the majority of taxos, justifying larger the variation of data the exception of the catch of the soil inner in the culture of aruana. In experiment 1 the groups Acari, Lepidoptera, Diptera, Coleoptera, Oligochaeta and Nematoda and nitrogen content, zinc, magnesium, manganese, phosphorus and calcium were those who 9 had contributed more in variation of the data. In experiment 2 the groups Isopoda, Diplura, Myriapoda, Acari and Dermaptera and the magnesium, nitrogen, phosphorus, zinc, copper, sodium, aluminum and iron were those who had contributed more in variation of the data. In experiment 3 the groups Lepidoptera, Hymenoptera, Diplura, Myriapoda, Protura and the magnesium, nitrogen, iron and manganese were those who had contributed more in variation of the data. In experiment 4 the groups Acari, Nematoda, Dermaptera, Protura, Diplura, Coleoptera and Oligochaeta and the contents of potassium, iron, copper and calcium were those who had contributed more in variation of the data.
O estudo foi realizado em uma propriedade rural, na localidade da Hidráulica no município de Capão do Leão - Rio Grande do Sul, Brasil, com objetivo de avaliar a influência dos fertilizantes mineral, organo-mineral e orgânico sobre a macrofauna e mesofauna do solo. Foram dispostos quatro experimentos individualizados em delineamento estatístico blocos casualizados com cinco tratamentos e seis repetições cada, em um ARGISSOLO AMARELO Distrófico típico, franco arenoso. Utilizou-se as seguintes culturas em sucessão: Zea mays L.-Consórcio forrageiro (Trifolium repens L., Trifolium pratense L., Lotus corniculatus L. e Lolium multiflorum Lam.); Sorghum bicolor L.-Brassica napus L.; Panicum maximum-Lolium multiflorum Lam.; Helianthus annuus L.-Triticum aestivum L. Investigaram-se os seguintes tratamentos: T1-Testemunha, T2-Fertilizante mineral, T3-Fertilizante organo-mineral, T4-Fertilizante-composto e T5-Fertilizante orgânico cama de peru . As variáveis analisadas foram: precipitação, propriedades químicas do solo (pHágua, pHSMP, condutividade elétrica, carbono orgânico, nitrogênio, carbono/nitrogênio, fósforo, potássio, cálcio, magnésio, ferro, alumínio, manganês, sódio, cobre e zinco), atributos físicos do solo (umidade e temperatura), respostas agronômicas (rendimento de grãos e de fitomassa) e a macrofauna e mesofauna do solo. A semeadura das espécies de verão se deu no mês de dezembro de 2007, enquanto as de inverno, foram a partir de maio de 2008. As colheitas foram realizadas nas culturas de grãos no final do respectivo ciclo, enquanto, nas forrageiras de verão e de inverno totalizaram-se sete e seis cortes sucessivos, respectivamente. Os resultados de temperatura do solo, umidade do solo e rendimento agronômico e representantes da fauna foram submetidos à análise de variância, teste de médias (Duncan 5%) de probabilidade. A fauna encontrada também foi submetida à análise de Densidade, Riqueza, Freqüência relativa, classificação por categoria de Abundância, índice de diversidade, índice de equitabilidade. Os resultados referentes à fauna edáfica, macronutrientes, micronutrientes e condutividade elétrica do solo foram submetidos também a análise multivariada. Conclui- se que: a menor diversidade e equitabilidade foram encontradas no Fertilizante mineral nas coletas realizadas no interior do solo do consórcio forrageiro, da canola, da aruana e do trigo. Assim como, nas coletas de superfície que mostram no milho, no consórcio forrageiro, na canola e na aruana e azevém os menores índices ecológicos. Os grupos Collembola, Acari, Hymenoptera e Coleoptera mostraram as maiores densidades entre os experimentos. O rendimento agronômico do milho e da aruana e azevém influenciaram mais na disposição da fauna edáfica nas coletas de interior do solo, enquanto que, nas coletas de superfície a maior contribuição foi no consórcio forrageiro no sorgo e no trigo. Aos Fertilizantes, composto e organo-mineral associaram-se mais efetivamente a maioria dos táxons, justificando-se a maior variação dos dados levantados nas coletas de interior e superfície do solo a exceção das coletas de interior do solo na cultura da aruana. No experimento 1 os grupos Acari, Lepidoptera, Diptera, Coleoptera, Oligochaeta e Nematoda e os teores de nitrogênio, zinco, magnésio, manganês, fósforo e cálcio contribuíram mais efetivamente com a variação dos dados. No experimento 2 os grupos Isopoda, Diplura, Myriapoda, Acari e Dermaptera e os teores de magnésio, nitrogênio, fósforo, zinco, cobre, sódio, alumínio e ferro contribuíram mais efetivamente com a variação dos dados. No experimento 3 os grupos Lepidoptera, Hymenoptera, Diplura, Myriapoda, Protura e os teores de magnésio, nitrogênio, manganês e ferro contribuíram mais efetivamente com a variação dos dados. No experimento 4 os grupos Acari, Nematoda, Dermaptera, Protura, Diplura, Coleoptera, e Oligochaeta e os teores de potássio, ferro, cobre e cálcio contribuíram mais efetivamente com a variação dos dados.
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Jubileus, Mandy Theresa. "Assessment of platinum mine tailings storage facilities : an ecotoxicological perspective / Mandy T. Jubileus." Thesis, North-West University, 2008. http://hdl.handle.net/10394/3729.
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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.
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Strecker, Tanja [Verfasser]. "The role of plant diversity, plant functional groups, and mineral nitrogen for soil microbial functioning and soil mesofauna in temperate grassland / Tanja Strecker." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2021. http://d-nb.info/1234236095/34.
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Carniel, Leticia Scopel Camargo. "Avaliação do risco ecológico de Mancozebe e Clorpirifós para representantes da macro e mesofauna do solo e eficiência de leitos biológicos de descarte." Universidade do Estado de Santa Catarina, 2015. http://tede.udesc.br/handle/handle/2440.
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Capes
Apple crops have huge importance to South Brazil economic, which concentrate more than 95% production in country. There are use of many pesticides in apples, with emphasis to fungicide Mancozeb and insecticide Chlorpyrifos. Although these substances have been developed to acting in a specific group of organisms, they are potentially dangerous to all alive organisms direct or indirectly exposed. Depending on persistence and toxicity, pesticides could interfering in soil basics process, how respiration and fauna soils activity, that directly influence nutrients cycling, organic matter decomposition and improvement physical chemical characteristics, being this products a risk to soil. Not application only, but handle and cleaning of machines with residues are dangerous to environmental too, and could induce punctual contamination. In some countries, to complete degradation of this waste, there is a bed for biological degradation, called Biobeds. Ecotoxicoly is a tool that could be used to measure pesticide risks and from their wastes to environmental receptor – since microorganisms until superiors vertebrates, having international protocols to application of assays. The aim of this study, was investigate toxicity caused by Mancozeb and Chlorpyrifos in two different Oxisols, representatives to apple crops, and effluent of pulverizer tank with wastes, to establish risks doses to three organisms from soil - Folsomia candida (Colembolla), Enchytraeus crypticus (Enchytraedae) e Eisenia andrei (Lumbricidae), using ISO protocols, and analyses Biobeds about its toxicity to organisms after contamination, comparing to natural soils, observing use possibility in handle of pesticides with spill simulation. Chlorpyrifos show higher toxic than Mancozeb, especially to Collembola (LC < 1 mg kg-1). Earthworm, organism used in Brazil’s law to approve pesticides was less sensible than other 18 19 for both products. Lethal and reproduction assays showed different risk doses in soils. Biobeds reduced waste pesticide risks during time and this not happen in one natural soil, that indicate dissolving products its not enough to reduce or eliminate the risks for soil organisms. In spill simulation, Biobeds was efficient in eliminate toxicity to earthworms and enchytraeids, although, not to Collembola and long time assays are necessary to reduce Chlorpyrifos toxicity to this organism. Due to large number of active ingredients using in agriculture actually, deep impact pesticide studies in soil organisms are necessary and alternatives of this wastes discharge
O cultivo de maçã tem grande representatividade na economia da região Sul do Brasil e uma série de agrotóxicos é utilizada, destacando-se o fungicida Mancozebe e o inseticida Clorpirifós. Apesar de essas substâncias serem desenvolvidas para atuar em um conjunto de organismos alvo, são potencialmente danosas para todos os organismos vivos expostos aos produtos. Dependendo de sua persistência e toxicidade, os agrotóxicos podem interferir em processos básicos do solo, tais como a respiração e a atividade da fauna edáfica que reflete diretamente na ciclagem de nutrientes, decomposição da matéria orgânica e melhoria de atributos químicos e físicos, representando estes compostos um risco para o solo. O manuseio e limpeza de maquinário com resíduos o produto também são potencialmente perigosas ao ambiente, podendo causar contaminações pontuais. Em alguns países para a completa degradação deste resíduo, são utilizados leitos biológicos de descarte (Biobeds). A ecotoxicologia é uma ferramenta que pode ser utilizada para mensurar o risco dos agrotóxicos e seus resíduos a receptores ambientais. O objetivo desta dissertação foi avaliar a toxicidade causada pelos ingredientes ativos Mancozebe e Clorpirifós em dois solos representativos para a cultura da maçã no Sul do Brasil – Latossolo e Nitossolo, e do efluente do tanque pulverizador com resíduos destes produtos, a fim de estabelecer dosagens de risco a três organismos representantes da fauna edáfica – Folsomia candida (Colembolla), Enchytraeus crypticus (Enchytraedae) e Eisenia andrei (Lumbricidae), e analisar Biobeds quanto a sua toxicidade aos organismos após sua contaminação, quando comparado aos solos analisados, observando a possibilidade de uso dos Biobeds para descarte de efluentes de agrotóxicos e como contensão em caso de derrame acidental. Foram realizados ensaios laboratoriais utilizando 14 15 protocolos ISO para ensaios letais (14 dias) e subletais (28 dias para colêmbolos e enquitreídeos e 56 dias para minhocas) de ecotoxicidade com os organismos indicados em câmara a 20ºC e fotoperíodo com 8/16 horas de luz/escuro. O Clorpirifós mostrou-se mais tóxico que o Mancozebe, principalmente aos colêmbolos, que são afetados em ensaios letais e subletais por doses < 1 mg kg-1. As minhocas, únicos organismos utilizados na legislação brasileira para credenciamento de agrotóxicos no mercado mostraram-se menos sensíveis que os colêmbolos e enquitreídeos aos dois produtos testados para ensaios letais (CL50), e subletais de reprodução (CE50), que apresentaram doses de risco distintas, e o Latossolo apresentando maior toxicidade quando contaminado pelos agrotóxicos testados. Os Biobeds reduziram a toxicidade dos agrotóxicos ao longo do tempo para os organismos edáficos, o que não foi observado no Latossolo, mostrando que mesmo um resíduo muito diluído, como o da lavagem do equipamento de aplicação, pode oferecer risco a fauna do solo ao longo do tempo. Na simulação de derrame acidental, os Biobeds foram eficientes em eliminar a toxicidade para minhocas e enquitreídeos, mas não para os colêmbolos, sendo necessários ensaios a longo prazo para determinar a possibilidade de redução da toxicidade do Clorpirifós aos organismos nesta situação. Devido ao grande número de ingredientes ativos utilizados na agricultura atualmente, são necessários estudos mais profundos do impacto destes agentes químicos à fauna edáfica, e também das alternativas de descarte dos resíduos oriundos dessa atividade
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Schubert, Ryan Noremberg. "Estudo da fauna edáfica na vermicompostagem de resíduos orgânicos." Universidade Federal de Pelotas, 2017. http://repositorio.ufpel.edu.br:8080/handle/prefix/3775.
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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.
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Ghezzi, Jessique L. "SOIL AND BIOSOLID NANO- AND MACRO-COLLOID PROPERTIES AND CONTAMINANT TRANSPORT BEHAVIOR." UKnowledge, 2014. http://uknowledge.uky.edu/pss_etds/44.
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Despite indications that they are potential contaminant transport systems and threats to groundwater quality, very little effort has been invested in comparing contaminant transport behavior of natural environmental nanocolloids and their corresponding macrocolloid fractions in the presence of As, Se, Pb, and Cu contaminants. This study involved physico-chemical, mineralogical, stability and contaminant-transport characterizations of nano- (< 100 nm) and macro-colloids (100-2000 nm) fractionated from three Kentucky soils and one biosolid waste. Particle size was investigated with SEM/TEM and dynamic light scattering. Surface reactivity was estimated using CEC and zeta potential. Mineralogical composition was determined by XRD, FTIR, and thermogravimetric analyses. Sorption isotherms assessed affinities for Cu2+, Pb2+, AsO3-, and SeO4-2 contaminants, while settling kinetics experiments of suspensions at 0, 2 and 10 mg/L contaminants determined stability and transportability potential. Undisturbed 18x30 cm KY Ashton Loam soil monoliths were also used for transport experiments, involving infusion of 50 mg L-1 colloid suspensions spiked with 2 mg L-1 mixed contaminant loads in unsaturated, steady state, unit gradient downward percolation experiments. Overall, nanocolloids exhibited greater stability over corresponding macrocolloids in the presence and absence of contaminants following specific mineralogy trends. Physicochemical characterizations indicated that extensive organic carbon surface coatings and higher Al/Fe:Si ratios may have induced higher stability in the nanocolloid fractions, in spite of some hindrance by nano-aggregation phenomena. In the transport experiments, nanocolloids eluted significantly higher concentrations of colloids, total, and colloid-bound metals than corresponding macrocolloids. Contaminant elutions varied by colloid type, mineralogy and contaminant, with the following sequences: soil-colloids>bio-colloids, smectitic>mixed≥kaolinitic>biosolid, and Se>Pb/Cu≥As. Our findings demonstrate that even though they behave more like nano-aggregates rather than individual nano-particles, nanocolloids may exhibit significantly higher mobility and contaminant transport potential over great distances in subsoil environments than their corresponding macrocolloid fractions.
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Crotty, Felicity Victoria. "Elucidating the relative importance of the bacterial and fungal feeding channels within the soil food web under differing land managements." Thesis, University of Plymouth, 2011. http://hdl.handle.net/10026.1/557.
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The overall aim of this thesis was to elucidate the relative importance of the bacterial and fungal energy channels within the soil food web and to differentiate and appreciate the differences in niche of the soil fauna when affected by differing land management. Feeding niche of the soil fauna is ambiguous and has been previously determined by observation, inference or biochemical studies. One method that can determine feeding preferences in situ is the use of stable isotopes. Stable isotopes trace the passage of C and N through different trophic levels, both at natural abundance and by the addition of a pulse of enrichment. The work described within this thesis describes the development of methods of culturing and labelling organisms for use in stable isotope studies. Bacteria, protozoa and fungi were cultured with stable isotopes enriched to 99 atom% and their growth and survival monitored. Utilising stable isotope enriched organisms means that empirical testing of the feeding interactions can occur and that differences between the bacterial and fungal energy channels can be explored. Two field sites were chosen to assess how management changes affect the food web, both sites were historically grassland with the same soil type, but one was converted to a willow woodland twenty years ago. The results of these studies have shown, at natural abundance a grassland and woodland habitat with very different stable isotope signatures, reflecting plant and soil composition, as well as differences in trophic niche and C drivers. The introduction of enriched bacteria illustrated that bacterial feeding was more widespread than normally portrayed in food web diagrams. The introduction of enriched protozoa highlighted that protozoan feeding by soil fauna was more prevalent in the grassland habitat; reflecting differences in linkages between trophic levels within the two habitats. Methods were also developed to “grow” enriched fungal hyphae back into soil food webs in a comparable way to the investigation of the bacterial energy channel. Different species of saprotrophic fungi were found to fractionate to differing extents when grown on the same natural abundance media and the fungus Absidia cylindrospora's growth was impacted when grown on a dually enriched medium. We can now infer that the bacterial energy channel is not as divergent from the fungal energy channel as previously hypothesised. The majority of soil fauna were found to be omnivorous through empirical results, consuming bacteria and protozoa, even when they were considered to be fungal feeders by the literature. The different habitats within the study were found to have different C drivers, with roots and soil being the primary driver in the grassland whilst litter was in the woodland, consequently favouring different food webs. This work makes a first step in measuring the contribution of the different feeding channels and feeding interactions occurring within the different trophic levels in the two habitats and shows the effect that one change in management has had over the entire faunal assemblage.
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Teets, Paul D. "Analysis of macro-, micro-, and trace elements of soil samples from Sanborn field /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p1418071.
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Rocha, André Gomes da. "Avaliação dos efeitos dos agrotóxicos Kraft® 36 EC e Score® 250 EC na flora, micro e mesofauna edáficas." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/18/18139/tde-30102017-164459/.
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As modificações ambientais provocadas pela humanidade, em especial pela agricultura, têm sido motivo de preocupação e estudos por todo o mundo. Nesse sentido, os solos figuram como um dos compartimentos ambientais mais impactados pelo uso de agrotóxicos, produtos amplamente utilizados na agricultura moderna. O objetivo deste trabalho foi avaliar se e como os agrotóxicos Score® 250 EC (i.a. difenoconazol) e Kraft® 36 EC (i.a. abamectina), isolados e em mistura, afetam a flora (germinação e crescimento do tomate - Lycopersicon lycopersicum), as comunidades microbianas do solo (biomassa microbiana em carbono, respiração, quociente metabólico e enzima β-glucosidase) e os enquitreídeos (reprodução de Enchytraeus crypticus em diferentes densidades e a relação trófica entre estes e os microrganismos), ao longo do tempo após a contaminação do solo. Em relação aos parâmetros microbianos, a despeito de algumas variações em decorrência da presença dos agrotóxicos, os indicadores das funções gerais do sistema edáfico não foram grandemente prejudicados, expressando uma redundância funcional. Não obstante, o solo-controle apresentou maior estabilidade em relação às variações dos parâmetros, sugerindo que os microrganismos presentes neste solo apresentaram uma maior robustez e estabilidade ao longo do tempo. Em relação aos testes com E. crypticus, os índices de reprodução não foram significativamente alterados em função da ação dos agrotóxicos, mas ratificou-se a importância dos microrganismos na dieta dos mesmos, haja vista as correlações entre o tamanho das comunidades microbianas e as taxas de crescimento dos enquitreídeos. Com relação ao crescimento e germinação do tomate, puderam ser observados valores maiores de altura e massa seca das plântulas em relação ao controle. Em contrapartida, observou-se uma possível melhor tendência de crescimento das plântulas no solo controle ao longo do tempo. Por fim, considerando a complexa problemática brasileira em relação ao uso de agrotóxicos, reiterou-se a importância do cumprimento das recomendações de aplicação de ambos os agrotóxicos avaliados por parte dos agricultores e recomendou-se a iniciativa de diminuição progressiva da sua utilização.Environmental changes caused by humanity, especially by agriculture, have been a cause for concern throughout the world. The soils are one of the environmental compartments most impacted by the use of pesticides, which are widely used in modern agriculture. This research aimed at evaluating whether and how the insecticide Kraft® 36 EC (a.i. abamectin) and the fungicide Score® 250 EC (a.i. difenoconazole), isolated and in mixture, affect: a) the soil microbial communities (microbial biomass carbon, respiration, metabolic quotient and β-glucosidase enzyme); b) enchytraeid worms (reproduction of Enchytraeus crypticus in different densities and their trophic relation with microorganisms); and c) the flora (emergence and growth of tomato - Lycopersicon lycopersicum), over 84 days after contamination. The microbial indicators were not greatly impaired and expressed a functional redundancy, despite some variations due to the presence of pesticides. Nevertheless, the control group presented a greater stability than the contaminated ones, suggesting a greater robustness and stability of microorganisms over time, which are important factors for a better quality of the soil. In relation to E. crypticus tests, the importance of microorganisms on their diet was ratified, since positive correlations between the size of microbial communities and the enchytraeids rate of increase were observed. The different densities of E. crypticus were not significantly influenced by the effects of pesticides on the microorganisms. With respect to the growth and germination of tomato, higher values of height and dry mass of the seedlings were observed in contaminated groups. On the other hand, a higher growth tendency of the seedlings in the control soil was observed over time. Finally, considering the complexity of the Brazilian pesticide issue, we emphasize the importance of compliance of the recommendations on pesticides application and reinforce the initiative of decreasing their use.
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Souto, Patrícia Carneiro. "Acumulação e decomposição da serapilheira e distribuição de organismos edáficos em área de caatinga na Paraíba, Brasil." Universidade Federal da Paraíba, 2006. http://tede.biblioteca.ufpb.br:8080/handle/tede/8199.
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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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Jian, Jinshi. "Global soil respiration: interaction with macroscale environmental variables and response to climate change." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/92195.
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The response of global soil respiration (Rs) to climate change determines how long the land can continue acting as a carbon sink in the future. This dissertation research identifies how temporal and spatial variation in environmental factors affects global scale Rs modeling and predictions of future Rs under global warming. Chapter 1 describes the recommend time range for measuring Rs across differing climates, biomes, and seasons and found that the best time for measuring the daily mean Rs is 10:00 am in almost all climates and biomes. Chapter 2 describes commonly used surrogates in Rs modeling and shows that air temperature and soil temperature are highly correlated and that they explain similar amounts of Rs variation; however, average monthly precipitation between 1961 and 2014, rather than monthly precipitation for a specific year, is a better predictor in global Rs modeling. Chapter 3 quantifies the uncertainty generated by four different assumptions of global Rs models. Results demonstrate that the time-scale of the data, among other sources, creates a substantial difference in global estimates, where the estimate of global annual Rs based on monthly Rs data (70.85 to 80.99 Pg C yr-1) is substantially lower than the current benchmark for land models (98 Pg C yr-1). Chapter 4 simulates future global Rs rates based on two temperature scenarios and demonstrates that temperature sensitivity of Rs will decline in warm climates where the level of global warming will reach 3°C by 2100 relative to current air temperature; however, these regional decelerations will be offset by large Rs accelerations in the boreal and polar regions. Chapter 5 compares CO2 fluxes from turfgrass and wooded areas of five parks in Blacksburg, VA and tests the ability of the Denitrification-Decomposition model to estimate soil temperature, moisture and CO2 flux across the seasons.
Cumulatively, this work provides new insights into the current and future spatial and temporal heterogeneity of Rs and its relationship with environmental factors, as well as key insights in upscaling methodology that will help to constrain global Rs estimates and predict how global Rs will respond to global warming in the future.Ph. D.
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Wang, Yuze. "Microbial-Induced Calcium Carbonate Precipitation : from micro to macro scale." Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/288238.
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Microbial-Induced Calcium Carbonate (CaCO3) Precipitation (MICP) is a biological process in which microbial activities alter the surrounding aqueous environment and induce CaCO3 precipitation. Because the formed CaCO3 crystals can bond soil particles and improve the mechanical properties of soils such as strength, MICP has been explored for potential engineering applications such as soil stabilisation. However, it has been difficult to control and predict the properties of CaCO3 precipitates, thus making it very challenging to achieve homogeneous MICP-treated soils with the desired mechanical properties. This PhD study investigates MICP at both micro and macro scales to improve the micro-scale understandings of MICP which can be applied at the macro-scale for improving the homogeneity and mechanical properties of MICP-treated sand. A microfluidic chip which models a sandy soil matrix was designed and fabricated to investigate the micro-scale fundamentals of MICP. The first important finding was that, during MICP processes, phase transformation of CaCO3 can occur, which results in smaller and less stable CaCO3 crystals dissolving at the expense of growth of larger and more stable CaCO3 crystals. In addition, it was found that bacteria can aggregate after being mixed with cementation solution, and both bacterial density and the concentration of cementation solution affect the size of aggregates, which may consequently affect the transport and distribution of bacteria in a soil matrix. Furthermore, bacterial density was found to have a profound effect on both the growth kinetics and characteristics of CaCO3. A higher bacterial density resulted in a quicker formation of a larger amount of smaller crystals, whereas a lower bacterial density resulted in a slower formation of fewer but larger crystals. Based on the findings from micro-scale experiments, upscaling experiments were conducted on sandy soils to investigate the effect of injection interval on the strength of MICP treated soils and the effects of bacterial density and concentration of cementation solution on the uniformity of MICP treated soils. Increasing the interval between injections of cementation solution (from 4 h to 24 h) increased the average size of CaCO3 crystals and the resulting strength of MICP-treated sand. An optimised combination of bacterial density and cementation solution concentration resulted in a relative homogeneous distribution of CaCO3 content and suitable strength and stiffness of MICP-treated sand. This thesis study revealed that a microfluidic chip is a very useful tool to investigate the micro-scale fundamentals of MICP including the behaviour of bacteria and the process of CaCO3 precipitation. The optimised MICP protocols will be useful for improving the engineering performance of MICP-treated sandy soils such as uniformity and strength.
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Larsson, Martin. "Quantifying macropore flow effects on nitrate and pesticide leaching in a structured clay soil : field experiments and modelling with the MACRO and SOILN models /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5489-1.pdf.
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Amarasinghe, Ruslan Shanth. "Macro-scale direct shear device for studying the large displacement shear strength of soil-structure interfaces under very low effective normal stresses." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44351.
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This thesis describes a new macro-scale test device for assessing the large-displacement
soil/solid interface shear strength at very low effective normal stresses (3 kPa to 6
kPa). The testing method arises from a need to obtain the interface friction between
soils and epoxy-coated pipes under low effective normal stress levels which is an
important consideration in the design of partly buried seabed pipelines. The test
device is fundamentally similar to the conventional small-scale direct-shear apparatus
except for its large footprint that provides a plan interface shear area of 1.72 m by
1.75 m. The device is designed to impart displacement-controlled interface-shearing
at displacement rates ranging from 0.0001 mm/s to 1 mm/s and with the ability to
reach a maximum interface shear displacement of 1.2 m. The desired normal stress at
the soil/solid interface is obtained using surcharge loads externally applied by means
of bulk sand or water masses, or both in certain cases. The device is instrumented
with pressure transducers mounted flush with the top surface of the solid test surface
for the measurement of pore water pressure at the shear interface, in turn, allowing
accurate determination of the effective normal stress at the soil/solid interface during
shearing. The key features of this device are described, and the device capabilities are
demonstrated by testing three soil types (Fraser-River sand, non-plastic silt, kaolinite)
on two test surfaces (mild steel, epoxy-coated mild steel) at effective normal stresses
between 3 kPa and 7 kPa. Comparison of the test results with available findings from
other devices is used to further confirm the suitability of the device for the intended
purpose.
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Raut, Yogendra Y. "Sustainable Bioenergy Feedstock Production Using Long-Term (1999-2014) Conservation Reserve Program Land." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu148344789416295.
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Bilibio, William Diniz. "Atributos físicos e químicos de um latossolo, fase cerrado, sob diferentes sistemas de manejo." Universidade Federal de Uberlândia, 2008. https://repositorio.ufu.br/handle/123456789/12098.
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Chemical and physical attributes of an Acrustox subjected to different management
systems were evaluated. The experiment was conducted at the Fazenda do Glória/UFU
since 2000. The field experimental area was conducted during seven years, in a
randomized block design, to evaluate some chemical and physical attributes of the soil,
at depths of 0-5, 5-15 and 15-30 cm, for different management systems (conventional
and conservationist). The parameters examined were: density, porosity, macro and
microporosity, aggregate stability, total organic carbon (TOC), phosphorus (P), calcium
(Ca2+), magnesium (Mg2+), potassium (K+), nitrogen (N) and aluminum (Al3+).
Statistical differences were found between conventional and conservationist treatments.
The values indicated a density increase with the depth, combined with porosity decrease
as the relationship macro/micropores and with lower aggregate stability in conventional
system in comparison with the conservationist systems. Statistical differences of the
chemical attributes of soil, between the conservationist and conventional treatments,
were found only at the top 5 cm of the soil, only for the elements Ca, P and K.
Aluminum correction was more efficient in the conventional system, due to lime
addition in the soil, independent of gypsum addition.Foram avaliados atributos físicos e químicos de um Latossolo Vermelho distrófico submetido a diferentes sistemas de preparo do solo. O experimento foi conduzido na Fazenda do Glória/UFU desde o ano 2000. A área experimental de campo, disposta num esquema de delineamento em blocos casualizados, foi conduzida durante sete anos para avaliar alguns atributos físicos e químicos do solo, nas profundidades de 0-5; 5-15 e 15- 30 cm, para diferentes sistemas de manejo (convencional e conservacionistas). Os parâmetros analisados foram: densidade, porosidade total, macro e microporosidade, estabilidade de agregados, carbono orgânico total (COT), fósforo (P), cálcio (Ca2+), magnésio (Mg2+), potássio (K+), nitrogênio (N) e alumínio (Al3+). Foram verificadas diferenças estatísticas entre os tratamentos conservacionistas e convencional. Os dados indicaram aumento da densidade com a profundidade, conjugado com redução da porosidade total, bem como da relação macro/microporos e com a menor estabilidade de agregados no sistema convencional, em relação aos sistemas conservacionistas. Para os atributos químicos do solo, diferenças estatísticas entre os tratamentos conservacionistas e convencional ocorreram apenas nos primeiros 5 cm do solo, somente para os elementos P, Ca e K. A correção do Al foi mais eficiente no sistema convencional, devido à incorporação do calcário ao solo, independente da aplicação de gesso agrícola.
Mestre em Agronomia
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Kriaučeliūnaitė, Kristina. "Makrofaunos (Lumbricidae) paplitimas agrofitocenozėse intensyvaus ūkininkavimo sąlygomis." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2006. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2006~D_20060607_164556-55484.
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In Magister work the spreading of macro fauna (Lumbricidae) in agrofitocenosis. Work object: research made in southwest Lithuania, Vilkaviškis region in the intensive agriculture farming in the hard granules ground. Aim of the work: to evaluate by field research southwest Lithuania hard granules soil macro fauna (Lumbricidae) spreading in agrofitocenosis depending on the kinds of growing plants, prior planting and hydrothermical regime. The methods of work: earthworm quantity was made digging 0,5 x 0,5m 2 and 0,25cm deep soil monolities and counting earthworms. By the research established that for earthworm quantity had influence growing plants, and their prior planting and hydrothermical regime. Most useful prior planting were barleys and long year grass. During research years between hydrothermical regime and earthworm number was defined strong and medium correlation relations.
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Pache, Gilles. "Les humus forestiers du massif de la Chartreuse : de l'approche macro-écologique à l'approche micro-écologique." Université Joseph Fourier (Grenoble ; 1971-2015), 1998. http://www.theses.fr/1998GRE10122.
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Le type d'humus que l'on peut observer sous foret resulte d'interactions nombreuses et complexes entre les conditions abiotiques (facteurs physiques et chimiques de l'environnement) et les facteurs biotiques (communautes vegetales, animales, fongiques et microbiennes). C'est en milieu montagnard (massif de la chartreuse), ou ces interactions sont mal connues, que nous avons etudies le determinisme et le fonctionnement des differents types d'humus a deux echelles de perception. A petite echelle (approche stationnelle), on observe un lien etroit entre la morphologie des humus et la repartition des especes vegetales. Cette morphologie est surtout dependante des facteurs physiques de l'environnement (bilan hydrique, aeration). A grande echelle, une etude du fonctionnement de quatre humus (deux mulls, un mor, et un tangel), correspondant a deux niveaux d'activite biologique tranches et a deux contextes edaphiques chimiques varies (acide et neutre), a ete menee. Le microclimat au sol des deux mulls differe de ceux du mor et du tangel par une xericite moindre, ceci etant essentiellement du a la vegetation herbacee tres differente. L'humidite edaphique est egalement plus elevee dans les deux humus de type mull (notamment grace a des apports par ruissellement). L'activite biologique (essentiellement lombricienne), tres superieure dans les deux mull, temoigne des conditions physiques favorables dans les deux mull, la xericite dans le tangel, et l'anoxie dans le mor, limitant cette activite.
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Zhang, Xi. "SPATIAL ESTIMATION OF HYDRAULIC PROPERTIES IN STRUCTURED SOILS AT THE FIELD SCALE." UKnowledge, 2019. https://uknowledge.uky.edu/pss_etds/117.
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Improving agricultural water management is important for conserving water during dry seasons, using limited water resources in the most efficient way, and minimizing environmental risks (e.g., leaching, surface runoff). The understanding of water movement in different zones of agricultural production fields is crucial to developing an effective irrigation strategy. This work centered on optimizing field water management by characterizing the spatial patterns of soil hydraulic properties. Soil hydraulic conductivity was measured across different zones in a farmer’s field, and its spatial variability was investigated by using geostatistical techniques. Since direct measurement of hydraulic conductivity is time-consuming and arduous, pedo-transfer functions (PTFs) have been developed to estimate hydraulic conductivity indirectly through more easily measurable soil properties. Due to ignoring soil structural information and spatial covariance between soil variables, PTFs often perform unsatisfactorily when field-scale estimations of hydraulic conductivity are needed. The performance of PTFs in estimating hydraulic conductivity in the field was therefore critically evaluated. Due to the presence of structural macro-pores, saturated hydraulic conductivity (Ks) showed high spatial heterogeneity, and this variability was not captured by texture-dominated PTF estimates. However, the general spatial pattern of near-saturated hydraulic conductivity can still be reasonably generated by PTF estimates. Therefore, the hydraulic conductivity maps based on PTF estimates should be evaluated carefully and handled with caution. Recognizing the significant contribution of macro-pores to saturated water flow, PTFs were further improved by including soil macro-porosity and were proven to perform much better in estimating Ks compared with established PTFs tested in this study. Additionally, the spatial relationship between hydraulic conductivity and its potential influencing factors were further quantified by the state-space approach. State-space models outperformed current PTFs and effectively described the spatial characteristics of hydraulic conductivity in the studied field. These findings provided a basis for modeling water/solute transport in the vadose zone, and sitespecific water management.
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Santonja, Mathieu. "Relations biodiversité-fonctionnement dans le contexte du changement climatique : application à la décomposition des litières en région méditerranéenne." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4754.
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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 climatiqueL'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
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Rizvi, Syed. "Amendements calco-magnésiens de bassins versants forestiers acidifiés : effets sur la dynamique de la matière organique et l'activité biologique du sol." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4796.
Full textAbstract:
L'objectif principal de ce travail est d'évaluer si l'amendement calco-magnésien de deux bassins versants acidifiés du massif vosgien (un sur grès et un sur granite) engendre des changements de la morphologie des humus, de l'abondance et de la diversité de la mésofaune, de la biomasse fongique, du stockage de carbone dans les horizons organiques 5 et 7 ans après l'amendement. Par ailleurs, nous avons effectué une étude dans des conditions contrôlées de laboratoire en utilisant des microcosmes contenant les horizons organiques du sol provenant de bassins versants acidifiés sur grès et sur granite afin d'évaluer les effets à court terme de l'amendement. Les résultats indiquent que les effets de l'amendement sont beaucoup plus marqués sur le substrat le plus acide. À court terme, sur substrat gréseux, nous observons une diminution de l'abondance de la mésofaune puis une augmentation de celle-ci 5 ans après l'amendement avant de ne montrer plus aucun effet 7 ans après l'épandage. L'effet inverse ou aucun effet n'est par contre observé sur substrat granitique. Le contenu en Ca et Mg de l'horizon OL a augmenté avec l'amendement, mais cet effet n'est également significatif que sur grès. La biomasse fongique du sol n'a pas été affectée par le chaulage, mais est significativement plus élevée sur granite que sur grès. Le chaulage a augmenté l'épaisseur de l'horizon OH sur grès alors qu'il a diminué l'épaisseur de l'horizon OL sur granite, probablement en relation avec les modifications de l'activité biologique (mésofaune ou microorganismes). Enfin, sur substrat gréseux, le stock de carbone de l'humus a augmenté du fait d'un épaississement notable de l'horizon OH avec le chaulageThe main objective of this work is to assess the consequences of calco-magnesium liming on two acidified forested catchments in Vosges Mountain (sandstone and granite) on humus morphology, abundance and diversity of mesofauna, fungal biomass and carbon storage in organic horizons 5 and 7 years after liming. Moreover, we performed a study to verify under laboratories conditions by using microcosms filled with soil from acidified catchments lying on sandstone and granite in order to study the short-term effect of calco-magnesium liming. During the two field campaigns, we determined calcium and magnesium contents of OL horizon, pH, humus morphology, mesofauna abundance and diversity, fungal biomass, soil carbon storage of organic layers OL, OF and OH.Results indicated that calco-magnesium liming affects studied parameters in different ways according to elapsed time after liming and the geological substrate (sandstone and granite), the more acidic catchment (sandstone) showing the most remarkable reaction. Results of immediate effects of liming showed a decrease of mesofauna abundance and then gradually increasing tendencies in field campaigns after 5 years while no effect after 7 years after liming. The opposite or no effects were observed on granite substrate. Ca and Mg contents in OL horizon increased by liming but this effect were only significant on sandstone substrate. Soil fungal biomass was not affected by liming but was significantly higher on granite substrate than sandstone. Liming increased the OH horizon thickness on sandstone while decreased the OL horizon on granite, under the influence of biological activity (mesofauna vs microorganisms)
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Govindin, Jean-Claude. "Les plantes de service : une alternative au travail du sol dans les systèmes de culture d’ananas." Thesis, Antilles-Guyane, 2014. http://www.theses.fr/2014AGUY0725/document.
Full textAbstract:
Pour beaucoup de cultures, un sol non travaillé est une alternative de plus en plus crédible au travail intensif du sol, en particulier pour des raisons environnementales. Mais l’ananas (ananas comosus) présente un enracinement fragile très sensible à la structure, ce qui motive souvent un travail important du sol avant plantation. L’alternative d’une plantation sans travail du sol ne va donc pas de soi. L’objet de cette thèse est de répondre à la question de la faisabilité d’une culture d’ananas sans travail du sol, en remplaçant ce dernier par une plante de service « décompactante » dont les traits racinaires seraient favorables à la (re)structuration d’un sol compact. Le travail de cette thèse a donc porté sur l’évaluation de plusieurs espèces candidates, puis sur l’étude, au champ, des effets sur le sol de la plus prometteuse (Stylosanthes guianensis ). Enfin, dans le cadre d’un essai au champ comparant un système de culture innovant ananas sans travail du sol, on a étudié l’effet de la plante de service sur le fonctionnement de la culture de l’ananas. Dans un premier essai, c’est le Stylosanthes guianensis qui, comparé à huit autres espèces (Arachis pintoï, Brachiaria decumbens, Cajanus cajan, Crotalaria juncea, Cynodon dactylon, Eleusine coracana, Pueraria phaseoloides, et le maïs), a montré les traits racinaires les plus favorables à la structuration d’un sol compact. Les valeurs supérieures du diamètre racinaire moyen et de la densité de longueur racinaire (DRL) caractérisent les principaux traits impliqués. Dans un deuxième essai, les mesures de conductivité hydraulique, d’indice des vides du sol et d’analyse d’images de blocs de sol imprégné sur la répartition surfacique des différents types de porosité ont montré que la culture du Stylosanthes guianensis avait augmenté l’indice des vides du sol et provoqué l’apparition d’une porosité fissurale de grande taille, contribuant ainsi à l’amélioration de la structure du sol. Enfin, un troisième essai mettant en comparaison (i) un système de culture innovant où la culture d’ananas est implantée sans travail du sol après une culture de S. guianensis restructurante et (ii) un système conventionnel comportant un travail profond du sol (et pas de plante de service) a montré que le rendement en fruit est similaire dans les deux systèmes. Cet essai a permis de vérifier que l’enracinement de l’ananas en condition de sol non travaillé bénéficiait du précédent S. guianensisFor many crops, direct drilling is a well-tried alternative facing the damaging effects of intensive tillage, mainly for environmental causes. But, pineapple (ananas comosus), presents a fragile rooting system which is very sensitive to soil structure. This leads frequently to intensive soil tillage before planting. Direct drilling is not so evident. The aim of this thesis is to give an answer to the feasibility of a no till system for pineapple cultivation, by using a plant with favorable roots traits for compacted soil (re)structuration. This work consisted in evaluating several candidate species, followed by the study, on the field, of the effects the most promising on soil (Stylosanthes guianensis). Finally, through a field experiment, comparing an innovating no till pineapple cultivation system we studied the use effects of Stylosanthes guianensis on the pineapple crop functioning. In a first experiment, Stylosanthes guianensis compared with eight other species (Arachis pintoï, Brachiaria decumbens, Cajanus cajan, Crotalaria juncea, Cynodon dactylon, Eleusine coracana, Pueraria phaseoloides and corn) showed better roots traits for structuring a compacted soil. Measures of average root diameter and root length density are the main implicated roots traits. In a second experiment, the measures of hydraulic conductivity, of the soil void ratio and the analysis of blocks of resin-impregnated soil on the surface distribution of the different type of porosity, all of this showed that Stylosanthes guianensis had increased the soil void ratio and had caused the creation of large-sized cracked porosity, thus contributing to the improvement of the soil structure. Finally, a third experiment involving a comparison between (i) an innovating cultivation system where pineapple is growing in a no till soil after a structuring crop of S. guianensis and (ii) a conventional system with deep tillage (without structuring crop), showed similar fruit yield. This experiment showed evidence that the rooting of pineapple in no till soil benefited from the previous Stylosanthes
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Robin, Vincent. "Reconstruction of fire and forest history on several investigation sites in Germany, based on long and short-term investigations - Multiproxy approaches contributing to naturalness assessment on a local scale." Thesis, Aix-Marseille 3, 2011. http://www.theses.fr/2011AIX30057.
Full textAbstract:
Sur la base de constats globaux concernant l’importance d’appliquer des modes de gestion durable des zones forestières et le manque d’investigation concernant l’histoire passée des feux en Europe centrale, il a été entrepris de reconstruire l’histoire des événements de feux et de la dynamique forestière pour des sites d’étude en Allemagne. L’ensemble des données obtenues et analysées ont été utilisées pour l’évaluation du niveau de naturalité des sites étudiés, cette notion étant essentielle pour la mise en place d’une gestion durable, et/ou pour des projets de conservation et / ou de restauration des systèmes perturbés. Concernant les dynamiques des écosystèmes en Europe centrale, il a été souvent mis en évidence que l’homme joue un rôle essentiel depuis des millénaires. Par conséquent, l’approche historique des événements de feux et de la dynamique forestière à été réalisée sur de longues échelles temporelles. Neuf sites d’étude ont été sélectionnés incluant une large gamme de systèmes forestiers d’Europe centrale. Les sites d’études sont répartis dans deux zones générales d’étude : le nord de l’Allemagne (Schleswig-Holstein), qui comprend quatre sites d’étude, et le centre de l’Allemagne (le Harz), qui comprend cinq sites d’étude. Quatre disciplines ont été principalement utilisées. Pour définir l’état actuel des sites d’études ceux-ci ont été caractérisés, utilisant divers indicateurs dendrométriques concernant la structure et la composition des parcelles analysées. Pour obtenir des informations à propos de la dynamique forestière des peuplements forestiers en place des analyses dendroécologiques ont été utilisées. Pour analyser la dynamique forestière sur une longue échelle temporelle, à une échelle spatiale comparable, des analyses pédoanthracologiques ont été menées, combinées à des analyses de sols. De plus, des analyses anthracologiques de séquences de tourbes ont été réalisées, fournissant, combinées avec les données pedoanthracologiques, des enseignements à propos de l’histoire des incendies. L’état actuel et la dynamique forestière récente des sites étudiés indiquent divers niveaux de complexité des peuplements forestiers, correspondant souvent à divers niveaux postulés d’impact anthropique. Il a été obtenu huit chronologies moyennes, standardisées en haute et moyenne fréquences, âgées au maximum de 1744 et au minimum de 1923 ans. A partir de ces chronologies des changements dans les conditions de croissance de peuplements forestiers ont été mises en évidence. Basées sur un ensemble de 71 charbons de bois datés par radiocarbone, il a été mis en évidence, à l’échelle locale et globale, deux principales phases présentant plus d’événements de feux datés, une durant le Pléistocène supérieur/Holocène inférieur, une autre durant l’Holocène supérieur. Pour les deux phases identifiées des forçages climatique et anthropogénique ont été respectivement postulés comme déterminisme des occurrences de feux. Finalement, les différentes données collectées ont été utilisées de façon combinée pour reconstruire l’histoire des feux et des forêts des sites étudiés, afin de contribuer à l’évaluation de leur niveau de naturalitéConsidering two global observations in Central Europe of, firstly, the need for, and development of, sustainable and biological conservation practices for forest and/or woodland areas and, secondly, the lack of long-term fire history, an attempt has been made to reconstruct the fire and the forest history at several investigation sites in Germany. The overall data set gathered and analyzed has been used for on-site naturalness assessment. This latter notion is crucial for forest system conservation/restoration planning, considering the past human impact on forest dynamics. Also, in view of this past human impact on forest systems, which is well-documented for Central Europe, as occurring on a multi-millennium scale, an historical perspective perceptive that combined a long and short temporal scale of investigation was used.Nine investigation sites were selected, in order to include various and representative types of Central European forest. Therefore, the investigation sites were located in two main investigation areas. One is in Northern Germany (Schleswig-Holstein) and includes four investigation sites. The other is in Central Germany (Harz Mountains) and includes five investigation sites. Four main approaches were used. To assess the current state of the investigated site, forest stand characterization was undertaken (i.e. based on various forest attributes that concern stand structure and composition). Tree ring series were analyzed to provide insights about short-term forest tree population dynamics. Then, charcoal records from soil (combined with soil analysis) and peat sequences were qualitatively and quantitatively analyzed. These last two approaches also provide information about the past fire history. Forest current and short-term dynamics illustrated various levels of stand complexity, often corresponding to various levels of human impact that had been postulated. Eight mean site tree-ring chronologies, standardized in high and mid-frequency signal, spanning at a maximum of up to AD 1744 and at a minimum of up to AD 1923, were obtained. The insight, about the identification of events of growing changes and the correlated temporal and, if possible, spatial patterns, was discussed. Charcoal analysis provided a long-term insight about fire history. Based on 71 charcoal radiocarbon dates, it was shown on a macro-scale that there were two phases that had a greater frequency of fire - one during the transition from the late Pleistocene to the early Holocene, and one during the mid- and late Holocene. A strong human control during the most recent fire phase has been postulated. This is supported by on-site soil and peat charcoal record analysis, allowing one to point out the event of environmental changes (disturbances), at local scales. In the end, the on-site data from the various indicators were combined to assess the fire and forest history and the naturalness level of the investigated sites, based on past insights, thereby contributing to a better understanding of the present and helping to anticipate the future
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Krause, Alena. "Changes in trophic niches of oribatid mites with transformation of tropical rainforest systems - from rainforest into rubber and oil palm plantations in Sumatra, Indonesia." Thesis, 2020. http://hdl.handle.net/21.11130/00-1735-0000-0005-1535-8.
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Strecker, Tanja. "The role of plant diversity, plant functional groups, and mineral nitrogen for soil microbial functioning and soil mesofauna in temperate grassland." Doctoral thesis, 2020. http://hdl.handle.net/21.11130/00-1735-0000-0005-15A7-7.
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Gonzalez, Mace Odette. "Flooding in a grassland diversity experiment: response of microorganisms, microarthropods and predator prey interactions." Doctoral thesis, 2018. http://hdl.handle.net/11858/00-1735-0000-002E-E431-6.
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Simões, Liliana Beatriz Pereira. "A dramatic turn of soil: how terrace construction influences the macro arthropods community on eucalypt plantations." Master's thesis, 2021. http://hdl.handle.net/10773/30830.
Full textAbstract:
To meet the needs of the pulp and paper industry, since the second half of the
twentieth century there has been an expansion of eucalyptus plantations in
Portugal. A technique commonly used in forest plantations in mountainous areas
in the north-central part of the country is soil terracing. However, this type of soil
preparation drastically changes its properties. Knowing that terrestrial biodiversity
is influenced by habitat conditions, this dissertation was intended to understand
the effects of the construction of terraces on the community of terrestrial macro
arthropods. In a first study carried out in a forest area located in Talhadas (Sever
do Vouga), 3 sites were compared - non terraced (NT), recently terraced (RT) and
terraced 14 years ago (OT). The results showed that the newly built terraces had
an average richness, abundance, diversity (H') and evenness (J') similar to the
non-terraced location. However, an increase in beetle’s richness and decrease of
spider richness was observed. Regarding the old terraces, no significant change
in the structure of the community was observed. In a second study, the soil macro
arthropod community was compared before (BT) and after (AT) the construction
of terraces, with seasonal samplings until completing one year. The results
revealed that terracing did not alter the overall abundance or richness in a
significant way, although the average abundance of coleoptera increased, and
Hymenoptera H’ and J’ decreased. An increase in the abundance of more
opportunistic and generalist families, of beetles and hymenopterans, was also
observed. In general, the present work reveals that although the construction of
terraces radically changes the soil, the effects on the community of ground
dwelling arthropods are not remarkable, particularly in the long term.Para responder às necessidades da indústria da pasta e do papel, desde a segunda metade do século XX que se tem assistido à expansão da plantação de eucalipto em Portugal. Uma técnica comumente utilizada nas plantações florestais em zonas montanhosas no centro-norte do país é a armação de solos em terraços. Contudo, este tipo de preparação de solos altera drasticamente as suas propriedades. Sabendo que a biodiversidade terrestre é influenciada pelas condições do habitat, com esta dissertação pretende-se compreender os efeitos da construção de terraços na comunidade de macro artrópodes terrestres. Num primeiro estudo conduzido numa área florestal localizada em Talhadas (Sever do Vouga), compararam-se 3 locais – não terraçado (NT), recentemente terraçado (RT) e terraçado há 14 anos (OT). Os resultados mostraram que os terraços recentemente construídos apresentavam uma média de riqueza, abundância, diversidade (H’) e equitabilidade (J’) similares ao local não terraçado. No entanto, foi observada uma maior riqueza de escaravelhos e menor riqueza de aranhas. No que respeita aos terraços antigos, não foi observada qualquer alteração significativa na estrutura da comunidade. Num segundo estudo comparou-se a comunidade de macro artrópodes de solo antes e após a construção de terraços, efetuando amostragens sazonais ao longo de um ano. Os resultados revelaram que a construção de terraços não alterou a abundância ou riqueza geral de forma significativa, no entanto a abundância media de coleópteros aumentou e a H’ e J’ de himenópteros reduziu. Observando-se também um aumento na abundância de famílias mais oportunistas e generalistas, em escaravelhos e formigas. De um modo geral, o presente trabalho vem revelar que muito embora a construção de terraços altere radicalmente os solos, os seus efeitos ao nível da comunidade de artrópodes do solo não são expressivos, nomeadamente no longo-termo.
Mestrado em Biologia Aplicada
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Grubert, Diana. "The soil food web of temperate deciduous forests: litter and root resources as driving factors, and soil fauna effects on ecosystem processes." Doctoral thesis, 2016. http://hdl.handle.net/11858/00-1735-0000-002B-7CE5-1.
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Mital, Utkarsh. "Understanding Micro- and Macro-Mechanics of Soil Liquefaction: A Necessary Step for Field-Scale Assessment." Thesis, 2016. https://thesis.library.caltech.edu/9712/7/Mital_Utkarsh_2016_Chapter1.pdf.
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Liquefaction is a devastating instability associated with saturated, loose, and cohesionless soils. It poses a significant risk to distributed infrastructure systems that are vital for the security, economy, safety, health, and welfare of societies. In order to make our cities resilient to the effects of liquefaction, it is important to be able to identify areas that are most susceptible. Some of the prevalent methodologies employed to identify susceptible areas include conventional slope stability analysis and the use of so-called liquefaction charts. However, these methodologies have some limitations, which motivate our research objectives. In this dissertation, we investigate the mechanics of origin of liquefaction in a laboratory test using grain-scale simulations, which helps (i) understand why certain soils liquefy under certain conditions, and (ii) identify a necessary precursor for onset of flow liquefaction. Furthermore, we investigate the mechanics of liquefaction charts using a continuum plasticity model; this can help in modeling the surface hazards of liquefaction following an earthquake. Finally, we also investigate the microscopic definition of soil shear wave velocity, a soil property that is used as an index to quantify liquefaction resistance of soil. We show that anisotropy in fabric, or grain arrangement can be correlated with anisotropy in shear wave velocity. This has the potential to quantify the effects of sample disturbance when a soil specimen is extracted from the field. In conclusion, by developing a more fundamental understanding of soil liquefaction, this dissertation takes necessary steps for a more physical assessment of liquefaction susceptibility at the field-scale.
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Li, Jianwei. "Effects of Land-Use History on Soil Macro- and Trace Elements in the Southern Piedmont of North America." Diss., 2009. http://hdl.handle.net/10161/1161.
Full textAbstract:
Land use histories affect the rate and pattern of soil nutrients at regional and global scale. However, former studies have rarely focused on soil trace elements (B, Mn, Zn, Cu and Fe). In this study, we aimed at the long-term biogeochemical cycling pattern and spatial heterogeneity of soil trace elements in response to land use changes. We conducted experiment at Calhoun experiment forest in SC and surrounded relic hardwood forest, cultivated land and secondary pine forests with contrasting land use histories in a statistically rigorous and spatially explicit design. Our first study indicated that spatial heterogeneity is greatly reduced in many soil properties by agricultural practices, but that successional forest growth on previously cultivated soils re-structures heterogeneity of soil properties within a few decades. We document cases in which land use alters both the soil property's central tendencies and their heterogeneity (C, N, CN, Ca, K), and cases in which changes are apparent in central tendency but much less so in their heterogeneity (Db). In our second study, samples of the upper 0.6-m mineral soil archived in 1962 and 1997 revealed three cycling patterns: 1) Extractable B and Mn were significantly depleted because tree uptake of B and Mn from mineral-soil greatly outpaced resupplies from atmospheric deposition, mineral weathering, and deep-root uptake. 2) Extractable Zn and Cu changed little during forest growth, indicating that nutrient resupplies kept pace with accumulations by the aggrading forest. 3) Oxalate-extractable Fe increased substantially during forest growth, by about 10-fold more than accumulations in tree biomass. This study indicated that forest Fe cycling is qualitatively different from that of other macro- and micro-nutrients. Thirdly, our results revealed that long-term cultivation substantially diminished the activity of soil iron oxides relative to forest growth. Forest Fe cycling is derived from mineral soil weathering, which suggests a need to explore the underlying mechanisms by which bioturbation (e.g.earthworms) mediates transformations of iron bioavailability and oxidation of organic matter in soils. Overall, the wide range of responses to land use changes among the ecosystem's trace elements and other biogeochemical features illustrates the great dynamics of the soil system over time scales of decades to centuries.
Dissertation
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Matla, Matsoele Moses. "Investigation into the Benthic macro-invertebrate fauna of the middle letaba impoundment, Gazankulu." Thesis, 1994. http://hdl.handle.net/10386/2113.
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Scheunemann, Nicole. "Carbon flow in belowground food webs assessed by isotope tracers." Doctoral thesis, 2015. http://hdl.handle.net/11858/00-1735-0000-0028-86B7-F.
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Ruby, Margaret E. "Forest macro-arthropods as potential indicators of ecosystem conditions in Western Idaho : an analysis of community composition, biological diversity, and community structure /." 2001. http://hdl.handle.net/1957/11060.
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"Effects of Land-Use History on Soil Macro- and Trace Elements in the Southern Piedmont of North America." Diss., 2009. http://hdl.handle.net/10161/1161.
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