O presente trabalho teve por objetivo compreender sistemas de produção agrícola e agropecuária a campo pela avaliação da diversidade, funcionalidade e dinâmica espaço-temporal de espécies, assim como pelo padrão de variação da qualidade do solo e dos fatores que a determinam. Para isso, foi avaliado na “Agropecuária Guajuvira” localizada no município de São Miguel das Missões – RS quatro sistemas conservacionistas de produção. Foram eles: 1- sistema agrícola tradicional, representando a sucessão soja/trigo e soja/aveia preta amplamente praticada na região; 2- Sistema agrícola irrigado, semelhante ao anterior, mas, com recente inserção de milho no verão; 3- Sistema integrado de produção agropecuária 1, representando a sucessão soja/pastejo de azevém e 4- Sistema integrado de produção agropecuária 2, representando um sistema misto por apresentar alterações na composição de espécies no inverno pela sucessão soja/aveia preta pastejada, soja/aveia preta não pastejada e soja/nabo forrageiro/trigo O estoque de carbono (EC), estabilidade de agregados do solo (EAS) e índice de manejo de carbono (IMC) foram escolhidos como indicadores da qualidade sistêmica do solo. Seus padrões de variação foram compreendidos pela integração de atributos químicos, físicos e biológicos do solo, assim como por variáveis de paisagem inerentes às unidades amostrais. Os fatores que caracterizaram os sistemas de produção e o uso da análise de caminhos permitiram um maior entendimento de sistemas complexos de produção agrícola e agropecuária a campo. / The aim of this research was to understand agricultural and integrated crop-livestock production systems by the species diversity, functionality and spatial-temporal dynamics evaluation, as well as of the variation pattern of soil quality and factors that determine then. For this, four no-tillage production systems were evaluated on the "Agropecuária Guajuvira" located in São Miguel das Missões county in southern Brazil. The production systems were: 1- Traditional agricultural system, representing the succession soybean/wheat and soybean/black oat widely practiced in the region; 2- Irrigated agricultural system, similar to the previous one, but, with recent insertion of corn in the summer; 3 - Integrated crop-livestock system 1, representing the succession of soybean /grazed ryegrass and 4 - Integrated crop-livestock system 2, representing a mixed system due changes in species composition during winter by succession of soybean/grazed black oat, soybean/no-grazed black oat and soybean/forage radish/wheat The carbon stock (CS), soil aggregate stability (SAS) and carbon management index (CMI) were chosen as systemic soil quality indicators. Their variation patterns were understood by the integration of chemical, physical and biological soil attributes, as well as by landscape variables inherent to the sampling units. The factors that characterized the production systems and the path analysis utilization allowed a greater understanding of complex agricultural and integrated crop-livestock production systems in the field.

Economic and environmental concerns surrounding nitrogen (N) have motivated efforts to improve estimates of plant available N in soil in order to improve crop N management decisions. Cover crops have been recognized as an effective tool for protecting soil and enhancing soil function including N cycling. This recognition has increased the adoption of cover cropping in the United States. Despite this growing popularity, there is lack of consistent response of cover crop on soil health and only a few experiments have examined how cover crop impacts nitrogen (N) management in corn. Therefore, the objectives of this study were to: a) quantify the impacts of cover crops on various soil health indicators like permanganate oxidizable carbon (POXC), CO2 burst, autoclaved-citrate extractable (ACE)-soil protein, b) investigate the relationship between soil health indicators, soil nitrate (NO3-N) and ammonium (NH4-N), corn N requirement and corn yield, and c) study the decomposition and N release of different cover crops. In a comparison of cover crop treatments, there was a trend of increasing permanganate oxidizable carbon (POXC) and CO2 burst with cover crop compared to no-cover crop control in the short term (1 year). Additionally, CO2 burst values were significantly increased for a long-term site with cover crops compared to the control in both 2021 and 2022. A long-term cover crop study at 25 sites showed a weak relationship of CO2 burst, POXC, soil protein and NO3-N with agronomic optimum N rate (AONR), with r values ranging from 0.00 to 0.48, suggesting these indicators may not be reliable predictors of N available in soil and corn yield. However, there was significant relationship between NO3-N at N sidedress time and relative yield (r = 0.65) at these long-term sites. In short-term cover crop study (Chapter 1), Presidedress nitrate test (PSNT) nitrate concentration was >15 mg kg-1 at 5 sites and in long term cover crop study (Chapter 2), 15 sites had nitrate concentration > 15 mg kg-1 indicating potential of N sidedressing reduction when compared to current pre-sidedress N test (PSNT) N recommendation in Virginia, which is currently only recommended for sites receiving manure or biosolids. A cover crop decomposition study at Kentland showed that hairy vetch had a faster decomposition rate (k = 0.0377 g g-1 d-1) than rye and vetch mix (k = 0.0292 g g-1 d-1) or cereal rye (0.0227 g g-1 d-1) with 0 N fertilizer and released more N than cereal rye and rye and vetch mix. The difference in C: N ratio (hairy vetch (9-11:1), cereal rye (31-46:1), rye and vetch mix (19-20:1)) may have affected decomposition rate and N release of cover crops. Hairy vetch released significant amounts of N within a month of incubation, with 103 kg N ha-1 in 2021 and 57 kg N ha-1 in 2022. Overall, this study showed that cover crops did not have a consistent or significant effect on soil health indicators in short term. However, cover crops improved CO2 burst at long term cover crop site compared to no-cover, control. Future studies should focus on understanding best methods of predicting N available to subsequent crop and conduct cover crop decomposition studies across the state with different cover crop species and their mixture. / Doctor of Philosophy / Increasing food production and fertilizer application especially nitrogen has degraded the soils capacity to provide nutrient to crops. Cover crops are crops planted after harvesting main crops like corn, soybean and cotton to protect soil from erosion and improve the soil's nutrient supply capacity. Planting cover crops in fall rather than leaving soil bare can be a best management practice to improve the soils and reduce the nitrogen loss to water bodies. The purpose of this study was to measure soil properties that shows how healthy the soil is, find the relation of soil properties with corn N requirement and corn yield, and estimate decomposition rate and nitrogen release after cover crop termination. Results showed that one year of cover crop versus no-cover crop had no effect on active carbon (permanganate oxidizable carbon, POXC), microbial respiration (CO2 burst). However, long term cover cropping increased CO2 burst. In long term cover cropping fields, nitrate concentration measured before N sidedress time (also called presidedress nitrate test, PSNT) was increased at 15 sites indicating these sites could reduce their N sidedressing. Cover crop decomposition study showed that decomposition and nitrogen release from hairy vetch was faster than cereal rye, and cereal rye and vetch mixture. Overall, planting cover crop showed did not improve in short term but planting cover crop for long term have potential to reduce the amount of nitrogen fertilizer need for corn, especially when legume cover crops are use.

Mudanças de uso da terra afetam a dinâmica da matéria orgânica e o acúmulo de C e N no solo e estão associadas a emissões de gases de efeito estufa (GEEs). A região Amazônica é relevante para as emissões brasileiras de GEEs oriundas das mudanças de uso da terra. O objetivo deste trabalho foi determinar alterações quantitativas e qualitativas nos estoques de C e N no solo em função de mudanças de uso da terra em Santarém-PA e São Luís-MA. Foram coletadas amostras de solo sob diferentes usos da terra: vegetação nativa, vegetação secundária, pastagem degradada, pastagem melhorada e agricultura anual. Adicionalmente, foram avaliadas áreas de mata queimada em Santarém-PA e de fruticultura e horticultura em São Luís-MA. Houve diferenças entre os solos de vegetação nativa nos dois locais, apesar dos estoques de C e N terem sido similares. Em Santarém, fósforo e granulometria relacionaram-se aos estoques de C e N. Em São Luís a acidez potencial ajudou a estimar o estoque de C; granulometria e capacidade total de troca de cátions estimaram o estoque de N. Os estoques de C e N na vegetação secundária foram similares aos da vegetação nativa nos dois locais e relacionaram-se com a acidez potencial do solo. Em Santarém o estoque de C (0-30 cm) na pastagem melhorada foi maior que na vegetação nativa. Em São Luís, o estoque de C foi semelhante ao da vegetação nativa. Os estoques de N tiveram comportamento similar aos estoques de C. Na pastagem melhorada de Santarém a soma de bases foi importante para estimar os estoques de C e N; em São Luís houve efeito negativo da densidade do solo. Estoques de C e N nas pastagens degradadas foram semelhantes à vegetação nativa, mas foram influenciados por parâmetros diferentes. Áreas de agricultura anual apresentaram estoques de C inferiores aos das pastagens melhoradas e da vegetação nativa e a sua manutenção relaciona-se com a redução da acidez potencial e com o aumento das bases trocáveis. A qualidade da matéria orgânica do solo foi avaliada nas amostras de São Luís. A mudança de uso da terra reduziu o C na fração orgânica (75-2000 ?m), mas os usos mais conservacionistas aumentaram o C nas formas estáveis (< 53 ?m). Vegetação secundária e pastagem recuperada apresentaram índice de manejo de C semelhantes aos da vegetação nativa. A conversão de vegetação nativa para agricultura ou pastagem reduziu o C na biomassa microbiana, mas os sistemas com grande aporte de material orgânico e com reduzida mobilização do solo apresentaram teor de C microbiano similar à vegetação nativa. Pastagem e agricultura também apresentaram os menores quocientes microbianos, indicando condição de estresse da biomassa microbiana. / Land use changes affect organic matter dynamics and the accumulation of C and N in the soil and are associated with greenhouse gas emissions (GHGs). Amazon region is relevant to Brazilian GHG emissions from land use changes. The aim of this study was to determine quantitative and qualitative changes in C and N stocks in the soil due to land use changes in Santarém (PA) and São Luís (MA). Soil samples were collected under different land uses: native vegetation, secondary vegetation, degraded pasture, improved pasture and annual agriculture. Additionally, we evaluated burnt forest areas in Santarém (PA) and fruit-growing and horticulture in São Luís MA. There were differences between the soils of native vegetation in both sites, despite the C and N stocks were similar. In Santarém, phosphorus and soil particle size were related to C and N stocks. In São Luís potential acidity was used to estimate C stock; soil particle size and total cation exchange capacity estimated N stock. C and N stocks in secondary vegetation were similar to those of native vegetation in both sites and related with the soil potential acidity. In Santarém C stock (0-30 cm) in improved pasture was greater than in native vegetation. In São Luís, C soil stock was similar to that of native vegetation. N stocks had similar behavior to C stocks. In improved pasture of Santarém sum of bases was important to estimate the C and N stocks; in São Luís there was negative effect of soil density. C and N stocks in degraded pastures were similar to native vegetation, but were influenced by different parameters. Annual agricultural areas had C stocks below those of improved pastures and native vegetation and its maintenance is related to the reduction of soil potential acidity and to the increase of soil exchangeable bases. Quality of soil organic matter was evaluated in samples of São Luís. Land use changes reduced the content of C in organic fraction (75-200 ?m), while more conservationists uses have increased the C in stable shapes (< 53 ?m). Secondary vegetation and improved pasture presented carbon management index similar to native vegetation. Conversion of native forest to agriculture or pasture reduced the C microbial biomass, but systems with large organic material input and with reduced tillage presented microbial C content similar to native vegetation. Pasture and agriculture also presented the smallest ratios of microbial biomass C to total organic C, indicating stress of microbial biomass.

Highway clients are increasingly concerned with the environmental consequences and sustainability implications of their highway maintenance service. This is because the service consumes a significant amount of natural resources, is financial and energy-intensive and is a large Greenhouse gas (GHG) emitter responsible for global warming and climate change. This has placed the highway maintenance sector, including its supply chain under increasing pressure to deliver well-maintained low-carbon maintenance service, whilst addressing its climate change impacts. The highway stakeholders increasing focus on carbon footprinting is a direct response to the legal obligation presented by the enactment of the UK s Climate Change Act (2008) and the Carbon Reduction Commitments. Investment decisions on highway infrastructure must now account for carbon and financial costs in a balanced manner. Highway clients now require their supply chains to demonstrate the capacity to reduce both direct and indirect carbon, and provide carbon footprint information relating to the work done or being tendered for. This is driving the sector to re-think its business operations within environmental, economic and social limits, which inherently presents risks and opportunities poorly understood by the stakeholders. It requires an in-depth understanding of the business operations, inputs and outputs. These business requirements are compounded given the lack of an agreed industrial methodology standard focusing on carbon footprinting, the knowledge and skill gaps, system boundary definitions, credible industrial data and their collection approach. The aim of this study is to develop a project-focused and process-based carbon footprinting methodology that includes a decision-support and carbon management tool to assist carbon management decision-making in highway maintenance planning and operation. This study then explored how the PAS2050 protocol can enhance the highway maintenance service delivery carbon footprinting and identify opportunities for reduction. It briefly reviews carbon emissions performance and the UK s highway maintenance sector, and developed a methodological framework that includes a carbon evaluation tool (the sponsor s business focus tool) based on the PAS2050 protocol. The framework developed is specific to highway maintenance planning and operation. It offers a carbon Life Cycle Assessment (LCA) tool that can identify emission hotspots across the process value chain, and inform a carbon reduction hierarchy. The implementation of the PAS2050-compliant methodology framework and the carbon evaluation tool for core highway maintenance processes (for example, pavement resurfacing, pavement marking, bulk lamp replacement and grass cutting), in addition to carbon footprinting across different site locations (urban, semi-urban and rural) are presented. The results indicate that materials production and their delivery to site (embodied carbon) are areas of carbon hotspots. This represents an important decision point for highway designers, managers and maintainers in order to deliver low-carbon service. These carbon hotspots suggest a less energy-intensive or green materials manufacturing process, responsible sourcing, use of recycled and secondary materials sourced locally (closer to sites) and delivered in bulk. The step-by-step carbon footprinting approach presented in this study is unique. It can be used by other sectors within the built environment as a pragmatic means of identifying and prioritising areas of potential carbon reduction through informed decision-making.

Mudanças de uso da terra afetam a dinâmica da matéria orgânica e o acúmulo de C e N no solo e estão associadas a emissões de gases de efeito estufa (GEEs). A região Amazônica é relevante para as emissões brasileiras de GEEs oriundas das mudanças de uso da terra. O objetivo deste trabalho foi determinar alterações quantitativas e qualitativas nos estoques de C e N no solo em função de mudanças de uso da terra em Santarém-PA e São Luís-MA. Foram coletadas amostras de solo sob diferentes usos da terra: vegetação nativa, vegetação secundária, pastagem degradada, pastagem melhorada e agricultura anual. Adicionalmente, foram avaliadas áreas de mata queimada em Santarém-PA e de fruticultura e horticultura em São Luís-MA. Houve diferenças entre os solos de vegetação nativa nos dois locais, apesar dos estoques de C e N terem sido similares. Em Santarém, fósforo e granulometria relacionaram-se aos estoques de C e N. Em São Luís a acidez potencial ajudou a estimar o estoque de C; granulometria e capacidade total de troca de cátions estimaram o estoque de N. Os estoques de C e N na vegetação secundária foram similares aos da vegetação nativa nos dois locais e relacionaram-se com a acidez potencial do solo. Em Santarém o estoque de C (0-30 cm) na pastagem melhorada foi maior que na vegetação nativa. Em São Luís, o estoque de C foi semelhante ao da vegetação nativa. Os estoques de N tiveram comportamento similar aos estoques de C. Na pastagem melhorada de Santarém a soma de bases foi importante para estimar os estoques de C e N; em São Luís houve efeito negativo da densidade do solo. Estoques de C e N nas pastagens degradadas foram semelhantes à vegetação nativa, mas foram influenciados por parâmetros diferentes. Áreas de agricultura anual apresentaram estoques de C inferiores aos das pastagens melhoradas e da vegetação nativa e a sua manutenção relaciona-se com a redução da acidez potencial e com o aumento das bases trocáveis. A qualidade da matéria orgânica do solo foi avaliada nas amostras de São Luís. A mudança de uso da terra reduziu o C na fração orgânica (75-2000 ?m), mas os usos mais conservacionistas aumentaram o C nas formas estáveis (< 53 ?m). Vegetação secundária e pastagem recuperada apresentaram índice de manejo de C semelhantes aos da vegetação nativa. A conversão de vegetação nativa para agricultura ou pastagem reduziu o C na biomassa microbiana, mas os sistemas com grande aporte de material orgânico e com reduzida mobilização do solo apresentaram teor de C microbiano similar à vegetação nativa. Pastagem e agricultura também apresentaram os menores quocientes microbianos, indicando condição de estresse da biomassa microbiana. / Land use changes affect organic matter dynamics and the accumulation of C and N in the soil and are associated with greenhouse gas emissions (GHGs). Amazon region is relevant to Brazilian GHG emissions from land use changes. The aim of this study was to determine quantitative and qualitative changes in C and N stocks in the soil due to land use changes in Santarém (PA) and São Luís (MA). Soil samples were collected under different land uses: native vegetation, secondary vegetation, degraded pasture, improved pasture and annual agriculture. Additionally, we evaluated burnt forest areas in Santarém (PA) and fruit-growing and horticulture in São Luís MA. There were differences between the soils of native vegetation in both sites, despite the C and N stocks were similar. In Santarém, phosphorus and soil particle size were related to C and N stocks. In São Luís potential acidity was used to estimate C stock; soil particle size and total cation exchange capacity estimated N stock. C and N stocks in secondary vegetation were similar to those of native vegetation in both sites and related with the soil potential acidity. In Santarém C stock (0-30 cm) in improved pasture was greater than in native vegetation. In São Luís, C soil stock was similar to that of native vegetation. N stocks had similar behavior to C stocks. In improved pasture of Santarém sum of bases was important to estimate the C and N stocks; in São Luís there was negative effect of soil density. C and N stocks in degraded pastures were similar to native vegetation, but were influenced by different parameters. Annual agricultural areas had C stocks below those of improved pastures and native vegetation and its maintenance is related to the reduction of soil potential acidity and to the increase of soil exchangeable bases. Quality of soil organic matter was evaluated in samples of São Luís. Land use changes reduced the content of C in organic fraction (75-200 ?m), while more conservationists uses have increased the C in stable shapes (< 53 ?m). Secondary vegetation and improved pasture presented carbon management index similar to native vegetation. Conversion of native forest to agriculture or pasture reduced the C microbial biomass, but systems with large organic material input and with reduced tillage presented microbial C content similar to native vegetation. Pasture and agriculture also presented the smallest ratios of microbial biomass C to total organic C, indicating stress of microbial biomass.

O objetivo desta pesquisa é entender como se dá a relação entre fatores humanos e práticas de gestão de baixo carbono sob a perspectiva da Visão Baseada em Recursos (VBR) no setor de biodiversidade, por meio da realização de survey e estudo de múltiplos casos. Assim, a seguinte problemática de pesquisa é elaborada: qual é a relação existente entre fatores humanos críticos de sucesso e a adoção de práticas de gestão de baixo carbono (sendo a Visão Baseada em Recursos o pano de fundo na análise)? A análise quantitativa (por meio da Modelagem de Equações Estruturais) evidenciou que as três ramificações da hipótese principal foram aceitas - sendo que a primeira com maior coeficiente que a segunda; e a segunda com maior coeficiente que a terceira. Dessa forma, observou-se que os fatores humanos influenciaram mais as práticas de gestão de baixo carbono de produto; em segundo lugar, as práticas de processo; e por fim as práticas de logística. A pesquisa qualitativa baseou-se na estratégia de múltiplos casos, com foco principal na relação entre os fatores humanos críticos de sucesso e a adoção (evolução) das práticas organizacionais de gestão de baixo carbono. Os resultados evidenciaram que as empresas se encontram em diferentes estágios de maturidade em relação às práticas organizacionais de gestão de baixo carbono, variando desde o estágio mais alto até o mais baixo. Verificou-se que a intensidade (de presença) dos fatores humanos críticos de sucesso foi maior à medida que a organização possuísse maior adoção de práticas de gestão de baixo carbono / The aim of this research is to understand the relationship between human factors and low carbon management practices from the perspective of the Resource Based View (VBR) in the biodiversity sector, through a survey and multiple cases study. Thus, the following research question is proposed: what is the relationship between human critical success factors and the adoption of low carbon management practices (Resource Based View as the background to the analysis)? The quantitative analysis (through Structural Equations Modeling) showed that all the three ramifications of the main hypothesis were accepted - the first one having a higher coefficient than the second one; and the second one with a higher coefficient than the third one. Thus, it was observed that the human factors influenced more the low carbon management practices of product; secondly, the process practices; and finally the logistics practices. The qualitative research was based on multiple case approach (6 cases), with a main focus on the relationship between critical human success factors and the adoption (evolution) of low carbon management organizational practices. The results showed that companies can be placed at different stages of maturity in relation to organizational practices of low carbon management, ranging from the highest to the lowest stage. It was found that the intensity of critical human success factors was greater as the organization had more adoption of low carbon management practices

O objetivo desta pesquisa é entender como se dá a relação entre fatores humanos e práticas de gestão de baixo carbono sob a perspectiva da Visão Baseada em Recursos (VBR) no setor de biodiversidade, por meio da realização de survey e estudo de múltiplos casos. Assim, a seguinte problemática de pesquisa é elaborada: qual é a relação existente entre fatores humanos críticos de sucesso e a adoção de práticas de gestão de baixo carbono (sendo a Visão Baseada em Recursos o pano de fundo na análise)? A análise quantitativa (por meio da Modelagem de Equações Estruturais) evidenciou que as três ramificações da hipótese principal foram aceitas - sendo que a primeira com maior coeficiente que a segunda; e a segunda com maior coeficiente que a terceira. Dessa forma, observou-se que os fatores humanos influenciaram mais as práticas de gestão de baixo carbono de produto; em segundo lugar, as práticas de processo; e por fim as práticas de logística. A pesquisa qualitativa baseou-se na estratégia de múltiplos casos, com foco principal na relação entre os fatores humanos críticos de sucesso e a adoção (evolução) das práticas organizacionais de gestão de baixo carbono. Os resultados evidenciaram que as empresas se encontram em diferentes estágios de maturidade em relação às práticas organizacionais de gestão de baixo carbono, variando desde o estágio mais alto até o mais baixo. Verificou-se que a intensidade (de presença) dos fatores humanos críticos de sucesso foi maior à medida que a organização possuísse maior adoção de práticas de gestão de baixo carbono / The aim of this research is to understand the relationship between human factors and low carbon management practices from the perspective of the Resource Based View (VBR) in the biodiversity sector, through a survey and multiple cases study. Thus, the following research question is proposed: what is the relationship between human critical success factors and the adoption of low carbon management practices (Resource Based View as the background to the analysis)? The quantitative analysis (through Structural Equations Modeling) showed that all the three ramifications of the main hypothesis were accepted - the first one having a higher coefficient than the second one; and the second one with a higher coefficient than the third one. Thus, it was observed that the human factors influenced more the low carbon management practices of product; secondly, the process practices; and finally the logistics practices. The qualitative research was based on multiple case approach (6 cases), with a main focus on the relationship between critical human success factors and the adoption (evolution) of low carbon management organizational practices. The results showed that companies can be placed at different stages of maturity in relation to organizational practices of low carbon management, ranging from the highest to the lowest stage. It was found that the intensity of critical human success factors was greater as the organization had more adoption of low carbon management practices

The quantity of stormwater runoff from the city of Adelaide almost matches the demand for drinking water. It therefore becomes increasingly important as an alternative source for water supply. This research focused at the Parafield Stormwater Harvesting Facility near Adelaide in order to better understand: (1) nutrient dynamics between the water column, sediments and plant community, (2) allochthonous and autochthonous sources of nutrients and (3) nutrient retention capacity of the reed bed. A weekly monitoring programme for the physical and chemical parameters of the water column, sediment and plant community was carried out over three years for specific locations within the reed bed. Ordination and clustering of the time series data revealed distinctive seasonal and spatial nutrient patterns. The concentrations for total nitrogen (TN) showed high concentrations for the summer period (1.04 to 1.86 mg/L) and low concentration for the winter season (0.25 to 0.46 mg/L). For the other nitrogen fractions in form of nitrate (NO₃⁻) and ammonium (NH₄⁺) the seasonal patterns were different to that of TN. In NO₃⁻ the concentrations were high during the summer and winter seasons and NH₄⁺ showed high concentration during the spring. The seasonality for total phosphorus (TP) showed high concentration for the spring period (0.049 to 0.163 mg/L) and low concentration for the other seasons (0.01 to 0.019 mg/L). A similar pattern has been observed for phosphate (PO₄³ ⁻) as well. The dissolved organic carbon (DOC) concentrations showed high concentrations during the summer period (21.36 to 31.64 mg/L) and low concentration during the winter seasons (5.48 to 7.14 mg/L). The seasonal pattern for the nutrient contents of the plant community showed highest concentrations during summer (5.5 to 34.2 gTN/kg) and lowest concentrations in winter (0.2 to 7.7 gTN/kg). Nutrient concentrations in the sediments were highest during the non-growing seasons (autumn and winter). This result indicated that the function of sediments changes seasonally from being a sink during the non-growing season by accumulating both allochthonous and autochthonous nutrients in the rainy season, and becoming a source during the growing seasons due to nutrient release from anaerobic sediments supporting the growth of the macrophyte community. Overall the function of sediment in reed bed pond of the Stormwater Harvesting Facility was to be a source of nutrients and therefore no accumulation of nutrients occurred during the study period. The research has demonstrated that the reed bed currently performs as a reasonable nutrient retention system with following nutrient removal rates: 0.85 mg TN /m²/day, 0.79 mg NO₃⁻ /m²/day, 0.28 mg NH₄⁺/m²/day, 0.05 mg TP /m²/day, 0.04 mg PO₄³ ⁻ /m²/day, and 5.75 mg DOC /m²/day. Seasonal difference in the water retention time showed that the for most of the nutrients the removal performance was most effective during autumn and winter with the exception of the removal performance of P forms, which most effective during spring and summer. For TN, NO₃⁻ and DOC the RE was most efficient at a residence time > 15days, for TP and PO₄³ ⁻ it is 5-10 days and for NH₄⁺ it is <;5days. Time–series modelling of the monitoring data resulted in rule-based prediction models for the different nutrients. Sensitivity analyses of the models revealed key driving variables for the nutrient dynamics of the reed bed. The prediction results revealed that the DO was the key driving variable influencing the nutrient concentrations in the water column and therefore to improve the water quality of the treatment water DO levels have to maintained above the threshold of 4 mg/L. Beside DO other key driving variables were turbidity, ORP and the nutrient levels from the previous site. Therefore the control of these parameters would be the start to develop a management plan for best-practice management in terms of water quality at the Parafield Stormwater Harvesting Facility. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1458926 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Science, 2010

The quantity of stormwater runoff from the city of Adelaide almost matches the demand for drinking water. It therefore becomes increasingly important as an alternative source for water supply. This research focused at the Parafield Stormwater Harvesting Facility near Adelaide in order to better understand: (1) nutrient dynamics between the water column, sediments and plant community, (2) allochthonous and autochthonous sources of nutrients and (3) nutrient retention capacity of the reed bed. A weekly monitoring programme for the physical and chemical parameters of the water column, sediment and plant community was carried out over three years for specific locations within the reed bed. Ordination and clustering of the time series data revealed distinctive seasonal and spatial nutrient patterns. The concentrations for total nitrogen (TN) showed high concentrations for the summer period (1.04 to 1.86 mg/L) and low concentration for the winter season (0.25 to 0.46 mg/L). For the other nitrogen fractions in form of nitrate (NO₃⁻) and ammonium (NH₄⁺) the seasonal patterns were different to that of TN. In NO₃⁻ the concentrations were high during the summer and winter seasons and NH₄⁺ showed high concentration during the spring. The seasonality for total phosphorus (TP) showed high concentration for the spring period (0.049 to 0.163 mg/L) and low concentration for the other seasons (0.01 to 0.019 mg/L). A similar pattern has been observed for phosphate (PO₄³ ⁻) as well. The dissolved organic carbon (DOC) concentrations showed high concentrations during the summer period (21.36 to 31.64 mg/L) and low concentration during the winter seasons (5.48 to 7.14 mg/L). The seasonal pattern for the nutrient contents of the plant community showed highest concentrations during summer (5.5 to 34.2 gTN/kg) and lowest concentrations in winter (0.2 to 7.7 gTN/kg). Nutrient concentrations in the sediments were highest during the non-growing seasons (autumn and winter). This result indicated that the function of sediments changes seasonally from being a sink during the non-growing season by accumulating both allochthonous and autochthonous nutrients in the rainy season, and becoming a source during the growing seasons due to nutrient release from anaerobic sediments supporting the growth of the macrophyte community. Overall the function of sediment in reed bed pond of the Stormwater Harvesting Facility was to be a source of nutrients and therefore no accumulation of nutrients occurred during the study period. The research has demonstrated that the reed bed currently performs as a reasonable nutrient retention system with following nutrient removal rates: 0.85 mg TN /m²/day, 0.79 mg NO₃⁻ /m²/day, 0.28 mg NH₄⁺/m²/day, 0.05 mg TP /m²/day, 0.04 mg PO₄³ ⁻ /m²/day, and 5.75 mg DOC /m²/day. Seasonal difference in the water retention time showed that the for most of the nutrients the removal performance was most effective during autumn and winter with the exception of the removal performance of P forms, which most effective during spring and summer. For TN, NO₃⁻ and DOC the RE was most efficient at a residence time > 15days, for TP and PO₄³ ⁻ it is 5-10 days and for NH₄⁺ it is <;5days. Time–series modelling of the monitoring data resulted in rule-based prediction models for the different nutrients. Sensitivity analyses of the models revealed key driving variables for the nutrient dynamics of the reed bed. The prediction results revealed that the DO was the key driving variable influencing the nutrient concentrations in the water column and therefore to improve the water quality of the treatment water DO levels have to maintained above the threshold of 4 mg/L. Beside DO other key driving variables were turbidity, ORP and the nutrient levels from the previous site. Therefore the control of these parameters would be the start to develop a management plan for best-practice management in terms of water quality at the Parafield Stormwater Harvesting Facility. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1458926 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Science, 2010

Submitted by MARCELO WILSON FURLAN MATOS ALVES null (marcelowilfma@hotmail.com) on 2016-04-22T16:48:29Z No. of bitstreams: 1 D_Desktop_3 folhas Alterações.pdf: 1745753 bytes, checksum: b26ea734a75327ecb57ea66a3a694d3a (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-04-26T12:47:06Z (GMT) No. of bitstreams: 1 alves_mwfm_me_bauru.pdf: 1745753 bytes, checksum: b26ea734a75327ecb57ea66a3a694d3a (MD5) / Made available in DSpace on 2016-04-26T12:47:06Z (GMT). No. of bitstreams: 1 alves_mwfm_me_bauru.pdf: 1745753 bytes, checksum: b26ea734a75327ecb57ea66a3a694d3a (MD5) Previous issue date: 2016-03-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo desta pesquisa é entender sob a perspectiva da teoria da contingência, como os fatores contingenciais climáticos e o gerenciamento interno organizacional realizado por um conjunto de empresas podem explicar a percepção de benefícios ao adotar práticas operacionais de baixo carbono. Para atingir este objetivo, o método de pesquisa escolhido foi entrevista, o qual foi conduzido com profissionais de seis empresas dividas em quatro setores industriais diferentes, utilizando para a análise dos dados o software NVivo a fim de entender as percepções dessas empresas estudadas. Os resultados encontrados foram: a) a percepção e o monitoramento de riscos climáticos disparam um gerenciamento interno organizacional mais estruturado pelas empresas; b) as empresas tendem a manter o modelo de gestão ambiental estabelecido para inserir fatores de mudanças climáticas em seus procedimentos; c) uma incipiente estrutura de gerenciamento interno organizacional presente nas empresas afeta suas percepções de benefícios ao adotarem práticas de baixo carbono, mesmo que diversifiquem suas ações; d) o gerenciamento de carbono sob os aspectos contingenciais pode explicar a inação das empresas neste contexto de mudança climática. Com isso, as contribuições deste trabalho consistem em fornecer à literatura evidências empíricas de como se estabelece a relação entre a percepção e o monitoramento de riscos com o gerenciamento de fatores climáticos organizacionais a partir do uso da teoria da contingência. Além disso, a pesquisa também contribui com discussões sobre a efetividade das ações em resposta aos eventos climáticos encarados pelas organizações. / The aim of this research is to understand, by the contingency theory perspective, how contingency climate factors and organizational internal factors management can explain the perception of benefits from adoption of low carbon operations practices by a set of enterprises. The research method chosen was interviews with specialists, which were made with professional of six enterprises in four different industries. The NVivo software was used to analyze data from interviews in order to understand the perceptions of those enterprises studied. The results found were: a) the perception and the monitoring of climate risks trigger organizational climate factors management better structured by enterprises; b) enterprises tend to keep the environmental management established to implant climate factors management in their procedures; c) incipient structure of climate factors management stand by in enterprises affect their perceptions of benefits when they have adopted low carbon operations practices, even they have diversified their actions; d) management carbon under contingencies aspects can explain the inaction of the enterprises in the climate change context. Therefore, this research contributes to literature through empirical evidences about how is the relationship between perception and monitoring of climate risks and organizational climate factors management by the perspective of contingency theory. Furthermore, the research contributes to discussion about the effectiveness of the actions in responding climate events faced by organizations.