A presente pesquisa tem como objetivo compreender a dinâmica de comportamento do solo sob escala macro e micromorfológica visualizados em topossequência, no que concerne aos agentes morfológicos que condicionam e contribuem para deflagração de processos erosivos. A área de estudo está inserida na sub-bacia hidrográfica do Laranja Azeda localizada na região centro-leste do estado de São Paulo, no município de São Carlos/SP, e têm fundamental importância por pertencer à bacia hidrográfica do Ribeirão Feijão, importante manancial urbano para a cidade. O planejamento de uso e ocupação adequados aos fatores físicos que compõe a dinâmica desta paisagem são essenciais visando a conservação e preservação dos recursos hídricos ali existentes, onde a expressiva ocorrência de processos erosivos são objetos de preocupação, já que estes podem causar assoreamento de rios e reservatórios. Utilizando uma metodologia multiescalar para seleção da área de pesquisa em detalhe e compreensão da organização e dinâmica da cobertura pedológica, foram utilizados os procedimentos propostos pela Análise Estrutural da Cobertura Pedológica e conceitos e técnicas da micromorfologia de solos. Verifica-se que a distribuição dos solos na Topossequência Manacá está estritamente correlacionada à transformação vertical do materialde origem em solo, em cuja vertente existe uma diferenciação litológica que condiciona a morfologia diferenciada, tanto em escala macromorfológica quanto micromorfológica. O terço superior e médio da vertente está associado à depósitos colúvio-eluvionaresda Formação Itaqueri, onde desenvolve-se um Latossolo Vermelho Amarelo. Já o terço inferior da vertente corresponde a um solo formado a partir dos arenitos da Formação Botucatu, sendo enquadrado enquanto Neossolo Quartzarênico. Com o auxílio técnicas de análise bidimensional de imagens retiradas das lâminas delgadas de solo, foi possível visualizar e quantificar a macroposidade ao longo da vertente, importante atributo morfológico que controla os fluxos de água e são agentes condicionantes para o desenvolvimento de processos erosivos. Conclui-se que a ocorrência de voçorocas no terço médio inferior da vertente é a materialização em forma de processos erosivos deste comportamento diferencial da massa do solo, onde portanto, na Topossequência Manacá a busca de equilíbrio dinâmico na vertente é induzida pela dinâmica genética evolutiva das formações geológicas que sustentam a paisagem, desencadeada em processos erosivos que tendem a progredir em desequilíbrio, a depender do manejo estabelecido para o local. / This dissertation aimed to understand the soil behavior under macro and micromorphological dynamic viewed in topossequence, in what concern the morphological agents that influence and con-tribute to outbreaks of erosion. The study area is within the sub basin of the brook Laranja Azeda, located in the central eastern region of São Paulo, in São Carlos / SP. Its study is of fundamental importance because it belongs to the basin of Ribeirão Feijão, an important source of water supply to the city. Planning the land use and occupation suited to the physical factors that compose the land-scape dynamics are essential to promote the conservation and preservation of water resources therein, where the significant occurrence of erosive processes are objects of concern, as these can cause silta-tion of rivers and reservoirs. It was applied a multiscale methodology to select the research area in detail for understanding the organization and soil cover dynamics, therefore, the procedures proposed by the Structural Analysis of Pedologic Coverage and also concepts and techniques of soil micromor-phology were used. It is found that the soil distribution in Toposequence Manacá is strictly correlated to the vertical transformation of the source material in soil, in which there is present a lithology dif-ferentiation, which makes the differentiated morphology both as macromorfológica micromorpho-logic scale. The upper and middle hillside its associated with colluvial alluvial deposits of Itaqueri formation, which develops a yellow red Oxisol. But the lower third of the hillside corresponds to a soil formed from the sandstones of the Botucatu Formation, being framed as Quartzipsamment. With the aid techniques bidimensional image analysis of thin sections taken from soil, it was possible to visualize and quantify macroposidade along the slope, a major morphological traits that controls wa-ter flow and is a conditioning agent to develop erosion. It is concluded that the occurrence of gullies in the lower and middle slope is the embodiment, in the form of erosion process, of this differential behavior of soil mass, where, in the Toposequence Manacá, the aim for dynamic equilibrium in the hillside is induced by genetic evolutionary dynamics of geological formations that underlie the land-scape, triggered in erosive process that tend to evolve unbalanced depending on the management of the land use established for the area.

In the present study the species boundaries of the scleractinian coral genus Goniopora from the Saudi Arabian Red Sea were investigated. An integrated morpho-molecular approach was used to better clarify the complex scenario derived from traditional classification efforts based on skeletal morphology. Traditional taxonomy of this genus considers skeletal morphology first and polyp morphology as a secondary discriminating character. This leads to potential complication due to plasticity in skeletal features within a species. To address this issue, molecular analyses of evolutionary relationships between nine traditional morphospecies of Goniopora from the Red Sea were performed and were used to re-evaluate the informativeness of macromorphological and micromorphological features. Between four and six putative molecular lineages were identified within Goniopora samples from the Saudi Arabian Red Sea on the basis of four molecular markers: the mitochondrial intergenic spacer between Cytochrome b and the NADH dehydrogenase subunit 2, the entire nuclear ribosomal internal transcribed spacer region, the ATP synthase subunit β gene, and a portion of the Calmodulin gene. The results were strongly corroborated by three distinct analyses of species delimitation. Subsequent analyses of micromorphological and microstructural skeletal features identified the presence of distinctive characters in each of the molecular clades. Unique in vivo morphologies were associated with the genetic-delimited lineages, further supporting the molecular findings. The proposed re-organization of Goniopora will resolve several taxonomic problems in this genus while reconciling molecular and morphological evidence. Reliable species-level identification of Goniopora spp. can be achieved with polyp morphology under the proposed revision.

Submitted by Anaclaudia Mattos Villalba (anaclaudiamattosvillalba@gmail.com) on 2016-04-06T19:09:28Z No. of bitstreams: 1 Dissertacao-final-correta-Paulo-Ellert-PPG-BAC.pdf: 987451 bytes, checksum: db08a30467b3fd80542ad5cda41b80fe (MD5) / Approved for entry into archive by cleuza maria medina dos santos (cleuzamai@yahoo.com.br) on 2016-04-15T00:35:25Z (GMT) No. of bitstreams: 1 Dissertacao-final-correta-Paulo-Ellert-PPG-BAC.pdf: 987451 bytes, checksum: db08a30467b3fd80542ad5cda41b80fe (MD5) / Made available in DSpace on 2016-04-15T00:35:25Z (GMT). No. of bitstreams: 1 Dissertacao-final-correta-Paulo-Ellert-PPG-BAC.pdf: 987451 bytes, checksum: db08a30467b3fd80542ad5cda41b80fe (MD5) Previous issue date: 2014 / Polygonum compreende aproximadamente 30 espécies distribuídas principalmente em regiões temperadas do hemisfério norte. Para o Brasil são aceitas 16 espécies, tipicamente de ambientes úmidos, sendo 10 registradas para o Rio Grande do Sul. A análise de caracteres morfológicos e a delimitação de espécies de Polygonum em ambientes úmidos do extremo sul do Brasil foi o objetivo deste estudo. O trabalho foi realizado com base em coletas, observações a campo e análises morfológicas pelo microscópio estereoscópico e MEV – microscópio eletrônico de varredura, em exemplares coletados e de Herbários. Foram registradas nove espécies: P. acuminatum Kunth, P. aviculare L., P. capitatum Buch.-Ham. ex D. Don, P. ferrugineum Wedd., P. glabrum Willd., P. hydropiperoides Michx., P. meisnerianum Cham. & Schltdl., P. persicaria L. e P. punctatum Elliot.. A separação das espécies se deve principalmente por características das inflorescências, como a forma, tamanho, localização e densidade de flores, forma dos frutos e presença/ausência de cílios nas ócreas. Polygonum hydropiperoides e P. punctatum são muito confundidas, distinguindo-se pelas inflorescências lineares interrompidas na base e presença de glândulas principalmente nas tépalas da última. Polygonum punctatum foi a espécie mais comum na área estudada. Por outro lado, P. persicaria mostrou ser rara no local por ter poucos indivíduos coletados, e especialmente P. aviculare, P. capitatum e P. glabrum, por só serem encontrados exemplares em herbário. O número de espécies registradas para a área estudada retrata a importância deste gênero para o extremo sul do Brasil, cuja área detém a quase totalidade de espécies registradas para o Estado. / Polygonum comprises about 30 species distributed mainly in high temperate regions of the northern hemisphere. For Brazil, 16 species are accepted, typically wet environments, being 10 recorded for the Rio Grande do Sul. The analysis of morphological characters and the delimitation of species of Polygonum in moist environments from southern Brazil was the objective of this study. The study was based on collections, field observations and morphological analyzes by stereoscopic microscope and SEM - scanning electron microscope, on specimens and in herbaria. Nine species were recorded: P. acuminatum Kunth, P. aviculare L., P. capitatum Buch.-Ham. ex D. Don, P. ferrugineum Wedd., P. glabrum Willd., P. hydropiperoides Michx., P. meisnerianum Cham. & Schltdl., P. persicaria L. and P. punctatum Elliot. Separation of species is mainly by characteristics of inflorescences, such as shape, size, location and density of flowers, fruit shape and presence/absence of cilia in ochreas. Polygonum hydropiperoides and P. punctatum are very confused, but are distinguished by linear inflorescences interrupted at the base and presence of glands especially in the last tepals. Polygonum punctatum was the most common species in the study area. On the other hand, P. persicaria shown to be rare in place by having a few individuals collected, especially P. aviculare, P. capitatum and P. glabrum, by being found only in herbarium specimens. The number of species recorded for the study area portrays the importance of this genre to the extreme southern Brazil, whose area holds almost all the species recorded for the State.

Este trabalho tem como objetivo avaliar o comportamento colapsível, sob o aspecto estrutural, de três perfis de solos tropicais típicos, que ocorrem na região norte do Paraná e que podem ser considerados representativos do território brasileiro. Dois desses perfis são classificados pela pedologia como Latossolos Vermelhos, um de textura argilosa e outro de textura média e o terceiro perfil, de textura argilosa, como Nitossolo Vermelho. Tem por objetivo, também, em função da abordagem pedológica adotada para a caracterização dos solos, poder associar comportamentos característicos observados para as diferentes classes estudadas, visando a extrapolação e aplicação desses conhecimentos a outros solos de ocorrência em zona tropical que se enquadrem nas mesmas classes dos materiais estudados. Ensaios edométricos simples e duplos foram conduzidos para a avaliação da colapsibilidade dos solos. O acompanhamento da evolução da macro e da microestrutura dos solos, antes e após colapso, através de análises micromorfológicas, permitiu estabelecer correlações com a dinâmica do colapso. Os resultados apontam um comportamento colapsível em todos os níveis dos perfis dos Latossolos enquanto que, para o horizonte característico do Nitossolo, as deformações volumétricas por inundação não foram suficientes para classificá-lo como colapsível. Os resultados ressaltam, ainda, a influência da tensão de pré-adensamento virtual e dos fatores pedogenéticos na variabilidade das características físicas dos solos analisados e na magnitude do colapso. Os maiores coeficientes de colapso parecem estar associados principalmente à presença, em maior proporção, de plasma microagregado com porosidade intermicroagregado fortemente comunicante; porosidade total elevada e existência de macroporos / Collapsible soils behavior, under the structural aspect, of three typical tropical soil profiles that occur in the region of North Paraná, considered representative in the national territory, are analysed at this thesis. Two of these profiles are classified by the pedology as Red Oxisoil, one of clayey texture and the other of medium texture. The third profile, of clayey texture is classified as Red Nitosols. The objective of this study is also to be able to extrapolate the result and behavior observed at this soil profiles for other sites which present similar characteristics on a pedological point of view. Double and simple oedometric tests were conducted for soil collapsibility evaluation. The evolution of the macro and microstructure of the soil were observed, before and after the collapse, through micromorphological analysis, allowing the establishment of correlations with the collapse dynamics. Test results point out to a collapsible behavior in all the levels of Oxisoil profile while for the characteristics horizon on Nitosol the volumetric deformation because of soaking was not sufficient to classify it as collapsible. Test results also highlight the influence of virtual pre-consolidation and pedogenetic factors in the variability of the physical characteristics of soil and in collapse magnitude. Highest collapsibility coefficient may to be mainly associated to the presence, in greater proportion, of microaggregate plasma with strongly communicating intermicroagregated void; high total porosity and the presence of macropores

Estudos sobre de métodos de preparo de solo são essenciais pela necessidade em se reduzir os impactos nos solos, decorrentes da intensificação da mecanização agrícola na cultura da cana-de-açúcar e pela busca de modelos que visem proporcionar uma maior qualidade para o solo e, consequentemente, a obtenção de melhores desenvolvimentos vegetativos e maiores produtividades. O presente trabalho teve como principal objetivo, a avaliação por meio de análises micromorfométricas, das alterações na estrutura do solo decorrentes de métodos distintos de preparo de solo. Foram avaliados o preparo convencional, a partir da mobilização do solo em área total, e o preparo profundo canteirizado, com a utilização de um modelo de implemento que permite realizar uma série de operações de preparo de solo de forma simultânea, que não mobiliza a região de passagem do rodado dos maquinários e delimita um canteiro preparado para o desenvolvimento das plantas. O solo da área experimental é classificado como Nitossolo Vermelho Eutrófico latossólico, de textura muito argilosa e foram abertas trincheiras nos tratamentos em momentos distintos do ciclo comercial da cultura, a fim de serem observadas as modificações de forma temporal. Nestas, foram coletadas amostras para análises de densidade do solo e amostras indeformadas de solo para a realização de análises micromorfométricas, para a quantificação e caracterização da área ocupada por poros, tanto na região de desenvolvimento da cultura (canteiro) quanto na área de passagem do rodado. Foi possível observar uma maior área ocupada por poros no canteiro do tratamento do preparo profundo canteirizado na primeira coleta, proporcionado pelo implemento, em relação ao preparo convencional, assim como uma maior participação de poros grandes complexos frente a poros de menor tamanho e arredondados. Porém, notou-se nas áreas sem influência do sistema radicular da planta, como na região de passagem do rodado e centro do canteiro, uma redução da área ocupada por poros entre uma coleta e outra, tanto por conta do tráfego agrícola quanto pela acomodação do solo desestruturado no preparo profundo canteirizado, podendo vir a acarretar em menores desenvolvimentos radiculares horizontalmente e deixando a área mais propicia a menores taxas de infiltração de água no solo, reduzindo o fluxo hídrico internamente e, consequentemente, aumentando os riscos da ocorrência de processos erosivos. Já no preparo convencional, os resultados indicaram uma manutenção da estrutura proporcionada pelo tipo de preparo entre as coletas, com poros menores e arredondados. / Studies about soil tillage methods are essential due to the necessity of reducing impact in soils caused by the intensification of mechanic agricultural operations in sugarcane. These studies are also important by the pursuit of models that enables a better quality to the soil and, as a consequence, obtaining better vegetative development and productivity. This study had as its main objective the evaluation of soil structural changes caused by different methods of soil tillage by micromorphometric analysis. Two soil tillage systems were evaluated, the conventional soil tillage, which mobilizes the soil in the whole area, and the deep bedding tillage, which is done by an agricultural implement that allows a series of operations simultaneously and does not mobilizes the soil in the wheel\'s path, delimiting a bed for the plant development. The soil of the experimental area is classified as a Eutric Nitisol with a high clay texture. Pitches were opened in the treatments in different timings during the commercial cycle of the culture aiming the observation of temporal modifications in the soil. Samples were collected for density analysis and undisturbed samples were collected for micromorphometric analysis, for quantification and characterization of the pore area in either the root development area (bed) or the wheel\'s path. It was possible to observe a largest pore area in the deep bedding tillage system on the first collection due to the implement when compared to the conventional, as well as a largest occurrence of complex pores against smaller rounded pores. However, it was observed in the areas without the direct influence of the root system, as in the wheel\'s path and bed center, a reduction of the pore area between the two collections because of agricultural machinery traffic and accommodation of the unstructured soil in the deep bedding tillage system. This occurrence might incur in lowering root development horizontally and letting the area prone to lower water infiltration, which reduces the water flow internally and increases the risk of erosive processes. As regards the conventional tillage system, the results indicated a structural maintenance enabled by the tillage method between the collections, presenting smaller rounded pores.

Estudos sobre de métodos de preparo de solo são essenciais pela necessidade em se reduzir os impactos nos solos, decorrentes da intensificação da mecanização agrícola na cultura da cana-de-açúcar e pela busca de modelos que visem proporcionar uma maior qualidade para o solo e, consequentemente, a obtenção de melhores desenvolvimentos vegetativos e maiores produtividades. O presente trabalho teve como principal objetivo, a avaliação por meio de análises micromorfométricas, das alterações na estrutura do solo decorrentes de métodos distintos de preparo de solo. Foram avaliados o preparo convencional, a partir da mobilização do solo em área total, e o preparo profundo canteirizado, com a utilização de um modelo de implemento que permite realizar uma série de operações de preparo de solo de forma simultânea, que não mobiliza a região de passagem do rodado dos maquinários e delimita um canteiro preparado para o desenvolvimento das plantas. O solo da área experimental é classificado como Nitossolo Vermelho Eutrófico latossólico, de textura muito argilosa e foram abertas trincheiras nos tratamentos em momentos distintos do ciclo comercial da cultura, a fim de serem observadas as modificações de forma temporal. Nestas, foram coletadas amostras para análises de densidade do solo e amostras indeformadas de solo para a realização de análises micromorfométricas, para a quantificação e caracterização da área ocupada por poros, tanto na região de desenvolvimento da cultura (canteiro) quanto na área de passagem do rodado. Foi possível observar uma maior área ocupada por poros no canteiro do tratamento do preparo profundo canteirizado na primeira coleta, proporcionado pelo implemento, em relação ao preparo convencional, assim como uma maior participação de poros grandes complexos frente a poros de menor tamanho e arredondados. Porém, notou-se nas áreas sem influência do sistema radicular da planta, como na região de passagem do rodado e centro do canteiro, uma redução da área ocupada por poros entre uma coleta e outra, tanto por conta do tráfego agrícola quanto pela acomodação do solo desestruturado no preparo profundo canteirizado, podendo vir a acarretar em menores desenvolvimentos radiculares horizontalmente e deixando a área mais propicia a menores taxas de infiltração de água no solo, reduzindo o fluxo hídrico internamente e, consequentemente, aumentando os riscos da ocorrência de processos erosivos. Já no preparo convencional, os resultados indicaram uma manutenção da estrutura proporcionada pelo tipo de preparo entre as coletas, com poros menores e arredondados. / Studies about soil tillage methods are essential due to the necessity of reducing impact in soils caused by the intensification of mechanic agricultural operations in sugarcane. These studies are also important by the pursuit of models that enables a better quality to the soil and, as a consequence, obtaining better vegetative development and productivity. This study had as its main objective the evaluation of soil structural changes caused by different methods of soil tillage by micromorphometric analysis. Two soil tillage systems were evaluated, the conventional soil tillage, which mobilizes the soil in the whole area, and the deep bedding tillage, which is done by an agricultural implement that allows a series of operations simultaneously and does not mobilizes the soil in the wheel\'s path, delimiting a bed for the plant development. The soil of the experimental area is classified as a Eutric Nitisol with a high clay texture. Pitches were opened in the treatments in different timings during the commercial cycle of the culture aiming the observation of temporal modifications in the soil. Samples were collected for density analysis and undisturbed samples were collected for micromorphometric analysis, for quantification and characterization of the pore area in either the root development area (bed) or the wheel\'s path. It was possible to observe a largest pore area in the deep bedding tillage system on the first collection due to the implement when compared to the conventional, as well as a largest occurrence of complex pores against smaller rounded pores. However, it was observed in the areas without the direct influence of the root system, as in the wheel\'s path and bed center, a reduction of the pore area between the two collections because of agricultural machinery traffic and accommodation of the unstructured soil in the deep bedding tillage system. This occurrence might incur in lowering root development horizontally and letting the area prone to lower water infiltration, which reduces the water flow internally and increases the risk of erosive processes. As regards the conventional tillage system, the results indicated a structural maintenance enabled by the tillage method between the collections, presenting smaller rounded pores.

A micromorfologia é a ciência que permite estudar o solo e seus componentes em amostras indeformadas em uma escala microscópica permitindo identificar feições relacionados a sua formação e processos atuantes que podem ser aplicadas em estudos de gênese, física, mineralogia, microbiologia do solo, entre outros. Para que isso seja possível é necessário formar um material rígido o suficiente para ser laminado a partir de amostras indeformadas de solo, através do processo de impregnação de solo. No entanto, para esse procedimento são utilizados atualmente, resinas plásticas (e.g. poliéster e epóxi), e dentre elas a resina poliéster, pode ser consideradas tóxica à saúde humana devido a presença do monômero de estireno na composição, além disso há o risco de danos ao meio ambiente devido a produção de resíduos oriundos de materiais tóxicos. No Brasil, por exemplo, há poucos laboratórios que realizam o processo de impregnação de amostras de solos para análises micromorfológicas, provavelmente, devido a toxicidade dos reagentes. Diante da importância da técnica para a Ciência do Solo, torna-se fundamental buscar alternativas para a técnica de micromorfologia do solo, que sejam economicamente viáveis, e que assegurem a segurança de atividades que envolvam substâncias e produtos químicos, visando garantir a proteção da saúde, da vida e das condições normais do ambiente, contribuindo para um desenvolvimento sustentável sem comprometer a qualidade do produto final. Assim, o presente trabalho teve como objetivo eliminar ou substituir a utilização do monômero de estireno no processo de impregnação de solos por substâncias similares menos tóxicas ao manuseio e avaliar o uso de soluções de resina poliéster e soluções de resina epóxi com diferentes diluentes (estireno, acetona e álcool) no processo de impregnação de amostras de solo (argiloso, textura média e arenoso). Para isso, foram utilizadas 2 tipos de resinas: resina poliéster Arazyn 1.0#00, resina poliéster Arazyn 1.0#0.8 e resina Epóxi Epoxiglass 1504; e diferentes solventes, sendo estes: o monômero de estireno, acetona P.A e álcool etílico absoluto (99,5%). Os tratamentos foram avaliados tanto para confecção de blocos quanto na fabricação de lâminas delgadas. Além disso, avaliação da qualidade da impregnação na confecção dos blocos de solo foi feita a partir dos parâmetros: odor, cor, volume de material gasto, solubilidade do pigmento, polimerização e secagem, corte, número de reimpregnações e custos dos reagentes. Também foi verificado na qualidade final do produto, a quantidade de poros não impregnados e uma avaliação qualitativa das lâminas. Verificou-se que a resina poliéster arazyn 1.0#08 tendo a acetona como solvente apresentou resultados satisfatórios na impregnação de solos, na confecção de blocos polidos e lâminas delgadas, para ambos os tipos de solo estudados. Porém, não foi capaz de substituir totalmente o estireno, contudo promove uma redução significativa do uso do estireno devido a possibilidade de substituição por acetona. Por outro lado, o tratamento com resina epóxi apresenta grande limitação da qualidade das lâminas delgadas não sendo obtidos resultados satisfatórios no produto final. No entanto, pode ser considerado uma alternativa para trabalhos que analisam apenas blocos polidos, uma vez que apresentou resultados positivos, em todas as texturas de solo que foram impregnadas. / Micromorphology uses optical microscopy and associated techniques to study soil\'s components at the microscopic scale for undisturbed samples. This technique allows identification of features related to soil processes and formation that can be applied to soil\'s genesis, physics, mineralogy, microbiology, among others. To perform these analysis, it is commonly used rigid materials to produce thin sections from undisturbed soil samples by the soil impregnation process. However, the plastic resins (e.g., polyester resin) containing the styrene monomer is considered toxic for human health. In addition, the wastes production from toxic materials may pose environmental risks. In Brazil, for instance, there are few laboratories performing the impregnation process of soil samples for micromorphological analysis, probably because of the reagents toxicity. Thus, given the importance of micromorphology for Soil Science, it is critical to seek other alternatives for soil micromorphology analysis. These alternatives must be economically feasible, chemically safe, non-hazardous for human health, attending environmental compliances, and contributing to sustainable development without compromising the product quality. Consequently, our work aimed to eliminate or replace the use of styrene monomer in the soil impregnation process by similar substances less toxic to the handling and evaluate the use of polyester resin solutions and epoxy resin solutions with different diluents (styrene, acetone and alcohol) in the impregnation process of soil samples (clayey, medium and sandy texture). We conducted an investigation using two resins, as follows: Arazyn 1.0 # 00 polyester resin, Arazyn 1.0 polyester resin # 0.8 and Epoxy resin Epoxiglass 1504; and the following solvents: styrene monomer, acetone and absolute ethyl alcohol (99.5%). We evaluated both blocks confection and thin sections manufacture. We also assessed the impregnation quality during soil blocks preparation based on the following parameters: odor, color, amount of material spent, pigment solubility, polymerization and drying, cutting, number of reimpregnations, and reagent costs. Within the product quality we also evaluate the non-impregnated pores quantities besides a qualitative evaluation of the thin sections. We found the polyester resin Arazyn 1.0 # 08 (containing acetone as a solvent) had satisfactory results in the impregnation of soil samples for both block soils and thin sections using the three soil texture types. Even though this treatment significantly decreased the use of styrene due to the potential substitution for acetone, we were unable to completely replace the styrene. On the other hand, the epoxy resin demonstrated limitations regarding the thin section quality, so that the results were not satisfactory for the final product. The epoxy resin can be considered a good alternative for analyzing soil blocks solely, since it presented positive results for the three impregnated soil textures.

Biobased materials made from renewable resources, such as wood, play an important role in the sustainable development of society. One main challenge of biobased building materials is their inherent moisture sensitivity, a major cause for fungal decay, mold growth and dimensional instability, resulting in decreased service life as well as costly maintenance. A new building material known as wood-plastic composites (WPCs) has emerged. WPCs are a combination of a thermoplastic matrix and a wood component, the former is usually recycled polyethylene or polypropylene, and the latter a wood processing residual, e.g. sawdust and wood shavings. The objective of this thesis was to gain more insight about characteristics of WPCs containing a modified wood component. The hypothesis was that a modified wood component in WPCs would increase the moisture resistance and durability in outdoor applications. The study comprises both injection molded and extruded WPC samples made with an unmodified, acetylated, thermally modified or furfurylated wood component in a polypropylene (PP), high density polyethylene (HDPE), cellulose ester (CAP, a cellulose ester containing both acetate and propionate substituents) or polylactate (PLA) matrix. The WPCs were prepared with 50-70 weight-% wood. The emphasis was on studying the moisture sorption, fungal resistance and micromorphological features of these new types of composites. Water sorption in both liquid and vapor phases was studied, and the biological performance was studied both in laboratory and in long term outdoor field tests. Micromorphological features were assessed by analyzing of the wood component prior to and after processing, and by studying the composite microstructure by means of a new sample preparation technique based on UV excimer laser ablation combined with scanning electron microscopy (SEM). Results showed that the WPCs with a modified wood component had a distinctly lower hygroscopicity than the WPCs with unmodified wood, which resulted in less wood-plastic interfacial cracks when subjected to a moisture soaking-drying cycle. Durability assessments in field and marine tests showed that WPCs with PP or CAP as a matrix and 70 weight-% unmodified wood degraded severely within a few years, whereas the corresponding WPCs with a modified wood component were sound after 7 years in field tests and 6 years in marine tests. Accelerated durability tests of WPCs with PLA as a matrix showed only low mass losses due to decay. However, strength losses due to moisture sorption suggest that the compatibility between the PLA and the different wood components must be improved. The micromorphological studies showed that WPC processing distinctly reduces the size and changes the shape of the wood component. The change was most pronounced in the thermally modified wood component which became significantly reduced in size. The disintegration of the modified wood components during processing also creates a more homogeneous micromorphology of the WPCs, which may be beneficial from a mechanical performance perspective. Future studies are suggested to include analyses of the surface composition, the surface energy and the surface energy heterogeneity of both wood and polymer components in order to tailor new compatible wood-polymer combinations in WPCs and biocomposites. / <p>QC 20121119</p>

Soil structure influences many chemical, biological and physical processes and it is well established that organic carbon acts as a soil binding agent. However, the precise location of organic matter and carbon in relation to structural features within intact samples is unknown. The sensitivity of organic carbon to decomposition is dependent not only upon its intrinsic chemical recalcitrance, but also its location within the soil structure. Soil structure provides organic carbon with chemical and physical protection, the extent of which varies between structural units. Furthermore soil structure is transient, and is sensitive to both environmental changes and physical disturbance, therefore it is difficult to determine and quantify the impact of this dynamic entity upon the storage of organic carbon. To date the majority of research that has advanced our understanding of the role soil structure plays in the storage of organic carbon, has relied upon some form of fractionation technique to separate aggregates from the bulk soil. However this approach has its disadvantages as much of the soil structure is destroyed; clearly when studying the impact of soil structure upon organic carbon-storage it is advantageous to implement any method that minimises disturbance to the soil structure. This study entails removing intact soil samples (through the use of kubiena tins) from long-term agricultural experimental fields at Rothamsted Research, (Hertfordshire, UK) with the aim of comparing and evaluating the location of organic matter and it’s associated organic carbon, in soils with contrasting organic carbon contents and a well documented land-use history. Thin sections will be analysed by integrating conventional micromorphology, image analysis and sub-microscopy combined with microscale chemical analysis scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). In doing so a new alternative method for analysing the distribution of organic matter and organic carbon is proposed. It was found that agricultural soils, which are the same in all aspects except total-OC content, differ in total organic matter, water release characteristics, aggregate stability and pore size distribution; therefore these differences could be attributed to the relationship between OC and soil structure. The water release curve, aggregate stability and pore size distribution also differed between soils with similar OC-contents but from different land-uses. The analysis of organic matter within intact soil samples provided evidence for the redistribution of organic matter as it is decomposed within the soil structure, for instance, less decomposed organ and tissue forms were located in or near to soil pores while more decomposed amorphous forms were located within the soil matrix. Since the same pattern of redistribution was observed in both agricultural and grassland soil this is likely to be directed by soil macro and micro fauna. It is concluded that since the location of different forms of organic matter is consistent across all soil, organic matter location is not responsible for creating differences in aggregate stability between treatments. Instead the results indicate that the amount and strength of organic carbon bonds and its hydrophobic properties are responsible. Micromorphology results demonstrated an absence of defined aggregation between treatments. Despite the difficulties in the interpretation of aggregation, the results contradict theories of aggregation, which state that aggregates are formed around “fresh” organic matter and it is argued that OM will undergo substantial decomposition before it acts as core for aggregation. Initial SEM-EDS analysis, has shown that in the soil matrix adjacent to organic matter (plant/organ) fragments there is a heightened concentration of C, indicating that these fragments are acting as a source of organic carbon. Interestingly BC, which represent one of the most recalcitrant C forms is also acting as a source of C, although these initial results suggest to a lesser extent than more labile C-sources. This source of organic carbon could stimulate microbial activity thereby enhancing soil structural stability. Alternatively, the release of liable carbon into soil pores may represent one route by which labile carbon enters sub-soil horizons.

Despite being a country synonymous with fishing and having very strong maritime traditions, the clear origins and development of specialist fishing communities prior to the mechanisation era in Iceland, particularly the Vestfirðir region, remain unclear. Further to this, the details of their chronological development are often erratic if not unknown. Historical records often recollect periods of success or failure, largely driven by economic narrative, however, the context, factors and responses to these changes have never been fully explored. Compounding this absence of information is the tendency for narratives to be accounting for Iceland as a whole, without giving allowance to any regional differences. By adopting an interdisciplinary methodology, underpinned by the application of geoarchaeology (the interpretation of the cultural record contained within soils and sediments), the chronological developments and historical narrative can begin to be established. The result of this research is a clearer understanding of the environmental history of fishing communities in the Vestfirðir region spanning over eight centuries, displaying evidence of a resilient and responsive society. As a result of this research, a clear distinction can now be made between sites which served maritime and terrestrial purposes based on the interpretation of the cultural material. The findings have produced a narrative detailing how a society has responded to wider environmental and social pressures driven by changes within Iceland and throughout Europe. The sites surveyed display unique variance in their characteristics of adaptation, reflecting a society which maintained a high degree of resilience and flexibility which essentially provides the foundation for one of the most successful fishing grounds in the world today.