Thesis (Ph. D.)--University of Hawaii at Manoa, 1995. / Includes bibliographical references (leaves 167-170). / Microfiche. / xx, 170 leaves, bound ill. 29 cm

Soil properties and their spatial variability was measured to provide a strong database to assess the modification in soil properties associated with future changes in land use. Surface (0--10 cm) soil samples were collected from a 9 ha, 46-year-old pasture being converted to a native tree plantation and a neighboring control pasture near Sardinilla, Panama. A small-scale nested grid of surface soil samples was replicated in the future plantation and a primary forest in the region to evaluate the spatial variability of soil properties. Seven 1 m profiles were sampled in the future plantation and litter samples were collected at the forest and the future plantation. / Assuming the three sites were identical before the conversion to pasture, the difference in surface soil organic carbon (SOC) was 0.75 kg m-2 or equivalent to a loss of 0.017 kg m-2 yr -1 since the original land-use change. The control pasture is higher in bulk density but lower in percent SOC than the future plantation, which is critical to future comparisons. / The pasture soils showed signs of soil compaction and of the homogenization of soil properties. For the 7 profiles in the future plantation, total SOC mass ranged from 13.45 to 23.80 kg m-2, and stable isotopes revealed that 82% of the SOC in the top 10 cm is derived from the pasture vegetation, down to 23% at 1 m depth. / Spatially, the full scale of spatial variability was not determined from the nested grids alone. In addition, the 15 x 15 m grid in the future plantation generally over-estimated the semivariance at the scales below 3 m. The nested grids assessed the minimum measurable semivariance below 5 m. / The precision of surface estimations from point observations can be improved by adding a 5 x 5 m grid to any large-scale sampling scheme.

No description available.

Studies were carried out in a lowland evergreen rain forest (LERF), on an ultisol, in the 'Reserva da Campina', 45 km north of Manaus, and in two facies of the highly distinct formation called heath forest, on spodosols. The spodosols had a layer of mor humus of thickness varying from nil in some parts in the smaller facies of heath forest (SHF) to 35 cm in the taller facies (THF). The overall aim was to investigate the forest soil biota and its role in nutrient turnover by comparing the SHF, THF and LERF. Microbial biomass, soil respiration and nitrogen transformation rates were measured in the three forest types in both wet and dry seasons. Field and laboratory fertilization experiments were made to investigate potential limiting nutrients for microorganisms and plants. The role of fine roots in decomposition and litter animal colonization was assessed in litter bag studies. SHF soils have a small microbial population with no net nitrification in any season. THF soils showed a variable microbial population adapted to high acidity, which immobilises nitrogen during the wet season, but which allows a net release during the dry season. LERF showed the most diverse population which causes mineralization and nitrification in both seasons. A bioassay with nutrient addition showed that the low pH, and nitrogen and sulphur supply were likely to be limiting nitrogen dynamics in all forest types, but especially in THF and LERF. The ingrowth bags showed that despite the lower values of fine root growth in the SHF (particularly when the white sand of the spodosol was used as the substrate), the roots showed in all plots an increased production with added calcium as carbonate or sulphate. In the decomposition bioassay to evaluate the role of roots in the nutrient turnover it was shown that in all forest types there was no effect of roots on the mass loss of Clitoria leaves but there was a significant effect on concentrations of some nutrients. In general, roots contributed to the accumulation of aluminium and iron and to a faster release and uptake of calcium, magnesium and zinc. A survey of the mycorrhizal associations in all forest types showed that both VAM and ECM fungi with some unknown VAM fungal species are common. VAM and ECM adaptation to low pH and high phenolic compounds in the soils may be important in the maintenance of these ecosystems.

Orientador: Heraldo Luiz Giacheti / Banca: Giulliana Mondelli / Banca: Roger Augusto Rodrigues / Resumo: Para a avaliação da contaminação dos solos em áreas de disposição de resíduos sólidos é fundamental conhecer a permeabilidade desses solos, quantificada pela condutividade hidráulica (k). Pesquisas anteriores avaliaram a contaminação que ocorre no Aterro de Resíduos Sólidos Urbanos de Bauru/SP, e sugerem valores de K para os solos que ocorrem no local. O objetivo desta pesquisa é dar continuidade aos estudos de investigação neste aterro, buscando encontrar valores representativos de K para os diferentes tipos de solos que ocorrem na área, empregando técnicas de ensaios em campo e laboratório. No laboratório foram realizados ensaios de condutividade hidráulica em permeâmetros de parede rígida e flexível a carga variável e constante em amostras indeformadas. Em campo, foram conduzidos ensaios de recuperação em poços de monitoramento (Slug Test), zona saturada, e ensaios de condutividade com o permeâmetro de Guelph na zona não saturada. Quatro tipos de solos são encontrados na região do aterro, coluvião, aluvião e residual de arenito. No laboratório, utilizando permeâmetros de parede rígida, foi possível encontrar valores médios de K para o colúvio e o alúvio, sendo estes, respectivamente, k=2,6x10-6, 2,0x10-5 m/s. Paro o solo residual e para o arenito utilizou-se de permeâmetros de parede flexível para a realização dos ensaios, com saturação por contra pressão, obtendo-se os valores de k=1,2x10-7 e 3,3x10-8 m/s, respectivamente. No campo para o solo residual encontraram-se valores de K de 3,7x10-7 m/s na zona saturada e de 3,4x10-7 e 1,3x10-7 m/s para a zona não saturada. No solo coluvionar obteve-se um valor de K de 5,3x10 na zona não saturada. No aluvião encontrou-se grande variação de K com a profundidade, obtendo-se um valor médio para a zona saturada d 7,9x10-7 m/s. Já, para... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In the assessment of soil contamination caused by solid waste disposal sites it is essential to investigate the soils permeability, quantified by the hydraulic conductivity (k). Previous research has assessed the contamination that occurs in the Brazil/SP Municipal Solid Waste disposal site, and suggested K values for the soils that occur at this site. The objective of this research is to continue the investigation studeies at the site, aiming to find representative K values for all the different soil types that occur in the area, using both laboratory and in situ testing techniques. Laboratory hydraulic conductivity tests were performed in rigid and flexibe wall permeameters by variable and constant head on undisturbed soil samples. Slug Tests in monitoring wells (saturated zone) and hidraulic conductivity tests with the Guelph permameter (unsaturated zone) were carried out in situ. Four types of soils are found in the site: colluvium, alluvium, sandstone and residual sandstone. The average K values for the colluviam and alluvium determined in the rigid wall permeameter were qual to 2.6x10-6 and equal to 2.0x10-5 m/s, respectively. The flexibe wall permeameter was used to carry out lab tests in the residual soil and sandstore, using backpressure saturation, obtaining the K values equal to 1.2 x 10-7 and equal to 3.3x10-8 m/s, respectively. A K value of 3.7x10-7 m/s for the residual soil was determined in situ in the saturated zone and K values of 3.4x10-7 and 1.3x10-7 m/s were determined in the unsaturated zone. For the colluvium soil, a K value of 5.3x10-6 m/s in the unsatured zone was determined. The K values varied with depth in the Alluvium, and the average valeu for the saturated zone was 7.9x10-7 m/s. It was not possible to carry out in situ tests in the residual soil. The representative K value were equal to 5.3x10-6, 1.1x10-4 and 1.2x10-7... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:26:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-06-22Bitstream added on 2014-06-13T19:33:41Z : No. of bitstreams: 1 jesus_ls_me_bauru_prot.pdf: 14176477 bytes, checksum: 1b3c89c43f22dd709d61a808988b4abe (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Para a avaliação da contaminação dos solos em áreas de disposição de resíduos sólidos é fundamental conhecer a permeabilidade desses solos, quantificada pela condutividade hidráulica (k). Pesquisas anteriores avaliaram a contaminação que ocorre no Aterro de Resíduos Sólidos Urbanos de Bauru/SP, e sugerem valores de K para os solos que ocorrem no local. O objetivo desta pesquisa é dar continuidade aos estudos de investigação neste aterro, buscando encontrar valores representativos de K para os diferentes tipos de solos que ocorrem na área, empregando técnicas de ensaios em campo e laboratório. No laboratório foram realizados ensaios de condutividade hidráulica em permeâmetros de parede rígida e flexível a carga variável e constante em amostras indeformadas. Em campo, foram conduzidos ensaios de recuperação em poços de monitoramento (Slug Test), zona saturada, e ensaios de condutividade com o permeâmetro de Guelph na zona não saturada. Quatro tipos de solos são encontrados na região do aterro, coluvião, aluvião e residual de arenito. No laboratório, utilizando permeâmetros de parede rígida, foi possível encontrar valores médios de K para o colúvio e o alúvio, sendo estes, respectivamente, k=2,6x10-6, 2,0x10-5 m/s. Paro o solo residual e para o arenito utilizou-se de permeâmetros de parede flexível para a realização dos ensaios, com saturação por contra pressão, obtendo-se os valores de k=1,2x10-7 e 3,3x10-8 m/s, respectivamente. No campo para o solo residual encontraram-se valores de K de 3,7x10-7 m/s na zona saturada e de 3,4x10-7 e 1,3x10-7 m/s para a zona não saturada. No solo coluvionar obteve-se um valor de K de 5,3x10 na zona não saturada. No aluvião encontrou-se grande variação de K com a profundidade, obtendo-se um valor médio para a zona saturada d 7,9x10-7 m/s. Já, para... / In the assessment of soil contamination caused by solid waste disposal sites it is essential to investigate the soils permeability, quantified by the hydraulic conductivity (k). Previous research has assessed the contamination that occurs in the Brazil/SP Municipal Solid Waste disposal site, and suggested K values for the soils that occur at this site. The objective of this research is to continue the investigation studeies at the site, aiming to find representative K values for all the different soil types that occur in the area, using both laboratory and in situ testing techniques. Laboratory hydraulic conductivity tests were performed in rigid and flexibe wall permeameters by variable and constant head on undisturbed soil samples. Slug Tests in monitoring wells (saturated zone) and hidraulic conductivity tests with the Guelph permameter (unsaturated zone) were carried out in situ. Four types of soils are found in the site: colluvium, alluvium, sandstone and residual sandstone. The average K values for the colluviam and alluvium determined in the rigid wall permeameter were qual to 2.6x10-6 and equal to 2.0x10-5 m/s, respectively. The flexibe wall permeameter was used to carry out lab tests in the residual soil and sandstore, using backpressure saturation, obtaining the K values equal to 1.2 x 10-7 and equal to 3.3x10-8 m/s, respectively. A K value of 3.7x10-7 m/s for the residual soil was determined in situ in the saturated zone and K values of 3.4x10-7 and 1.3x10-7 m/s were determined in the unsaturated zone. For the colluvium soil, a K value of 5.3x10-6 m/s in the unsatured zone was determined. The K values varied with depth in the Alluvium, and the average valeu for the saturated zone was 7.9x10-7 m/s. It was not possible to carry out in situ tests in the residual soil. The representative K value were equal to 5.3x10-6, 1.1x10-4 and 1.2x10-7... (Complete abstract click electronic access below)