O cultivo protegido em casas de vegetação possibilita produção vegetal de maior qualidade e em qualquer época do ano. A tecnologia tem papel preponderante no controle desses ambientes, embora nem sempre seja satisfatoriamente empregada. Soluções convencionais, como as que utilizam Controladores Lógicos Programáveis, ou sistemas com tecnologia proprietária predominam nas soluções oferecidas. A evolução da tecnologia de comunicação vem possibilitando a difusão do uso da tecnologia de redes de computadores em outras aplicações, as chamadas redes de controle, possibilitando a mudança de paradigmas na concepção de sistemas de monitoramento e controle. Os sistemas com arquitetura centralizada tendem a dar lugar aos com arquitetura distribuída, e o uso da Internet possibilita a supervisão e operação de qualquer lugar. Este trabalho discute a adoção da tecnologia de redes de controle em casas de vegetação, envolvendo aspectos de sua arquitetura, distribuição da inteligência, crescimento incremental, flexibilidade e custos. Ele foi aplicado a uma casa de vegetação do Instituto de Biociências da Universidade de São Paulo, dotada de sistema de automação convencional, para a implantação e avaliação de um sistema experimental baseado na rede de controle com a tecnologia LonWorks®. Utilizaram-se nós inteligentes comercialmente disponíveis e um nó desenvolvido em laboratório. A implementação permitiu a verificação experimental das vantagens e desvantagens da utilização da abordagem distribuída em relação à centralizada. Constatou-se a facilidade de implementação, redução no cabeamento, flexibilidade e interoperabilidade da solução. Contudo, os custos tendem a ser mais elevados na abordagem distribuída, no que se refere às ferramentas de apoio e nós inteligentes. Além da avaliação de aplicação da nova tecnologia, propõe-se uma seqüência de passos a se seguir na migração de um sistema convencional para um sistema de controle distribuído, e apresenta-se a disponibilização do sistema desenvolvido como um Web Lab, que possibilita a realização de experimentos remotamente. / Protected agriculture using greenhouses allows high quality crops and in any time of the year. The technology has a preponderant role in the control of these environments, although no always successfully. Conventional solutions, such as Programmable Logic Controllers, or systems with proprietary technology are predominant. The evolution of the communication technology is making possible the diffusion of computer networks use in other applications: control networks start to awake the interest of both researchers and users, changing the paradigm of monitoring and control systems conception. The traditional systems with centralized architecture tend to be replaced by distributed technology, and the Internet use makes possible the supervision and control from anywhere. This work discusses the control networks technology applied to greenhouses, involving architecture aspects, intelligence distribution, incremental growth, flexibility and costs. For the implementation and assessment of an experimental system based on LonWorks® technology, a greenhouse at Instituto de Biociências at Universidade de São Paulo was used. Off the shelf intelligent nodes were used and an experimental node was developed. The implementation made possible the experimental verification of advantages and disadvantages of the use of distributed and centralized approach. It was evidenced easiness of implementation, cabling reduction, flexibility and interoperability of the solution. However, the costs tend to be raised in the distributed approach, referring to support tools and intelligent nodes. Besides the new technology application evaluation, a step-by-step sequence is proposed for the migration from a conventional system to a control system, and presents a Web Lab system that enables remote experimentation.

A critical evaluation of the national profile of energy supply and demand and the associated greenhouse gas (OHO) emissions in China has been conducted. The contribution of the transport sector in China, the road transport sector in particular, to China's overall energy demand and OHO emissions has been assessed and compared with values for other countries. Approaches for reducing energy demand and OHO emissions in the road transport sector worldwide have been reviewed. A detailed bottom-up model has been developed using 'LEAP' software, to estimate future energy demand and OHO emissions in China's road transport sector, incorporating China's recent efforts in alternative fuel promotion. Modelling approach and historical data used have been tested and verified to ensure reliability. Two scenarios have been designed to describe the future strategies relating to the development of China's road transport sector between 2005 and 2030. The 'Business as Usual' scenario is used as a baseline reference scenario, in which the government is assumed to do nothing to influence the long-term trends of road transport energy demand. The 'Best Case' scenario is considered to be the most optimized case where a series of available reduction measures are assumed to be implemented. Energy demand and OHO emissions in China's road transport sector up to 2030 are estimated in these two scenarios. The reduction potential and the relative contribution of each measure have been estimated. A 'life cycle assessment' model for the road transport sector has been developed. The life cycle energy demand and OHO emissions in China's road transport sector are estimated using the model. The reduction potential and the relative contribution of each measure have been re-assessed from a life cycle perspective. Potential impacts on global oil resources, availability and prices are discussed. The importance of life cycle assessment in evaluating the effects of different reduction measures is discussed. Policy implications are presented.

As part of the response to the threat of dangerous climate change a variety of methods have emerged for measuring greenhouse gas emissions to the atmosphere, assigning responsibility for those emissions, and informing decisions on mitigation actions. Many of these greenhouse gas accounting methods have developed in semi-isolated fields of practice, and this raises questions about how these different methods relate to each other, and whether they form ‘families’ of conceptually similar approaches. A useful distinction has developed within the field of life cycle assessment (LCA) between attributional and consequential methods, and this thesis explores the possibility of extending that distinction to categorise other forms of greenhouse gas accounting. Broadly, attributional methods are inventories of emissions/removals for a defined inventory boundary, while consequential methods aim to estimate system-wide changes in emissions that result from a decision or action. This thesis suggests that national greenhouse gas inventories, city inventories, corporate inventories, and attributional LCA are all attributional in nature, while project-level assessments, policy-level assessments, and consequential LCA are all consequential in nature. The potential benefits from creating this categorical framework include ensuring that individual methods are conceptually coherent, transposing lessons between methods of the same categorical type, and ensuring that the correct type of method is used for a given purpose. These various benefits are explored conceptually through the analysis of existing greenhouse gas accounting standards, and also empirically with the use of a bioenergy case study. The findings suggest that the attributional-consequential distinction is highly useful for conceptualising and developing greenhouse gas accounting methods, which is important, ultimately, for addressing dangerous climate change.

Dairy production systems are an important global contributor to anthropogenic greenhouse gas (GHG) emissions including methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2). Due to the role GHG play in climate change, it is important to investigate ways to minimise their global warming potential (GWP) and to maximise the efficiency of dairy production systems. Finding a balance between improving productivity and suppressing the range and quantity of GHG produced in dairy production is crucial in order to maintain sustainability in the future. The Langhill herd is part of a long term genetic x feeding systems study, representative of a range of dairy production systems which may be found in the UK. Two feeding regimes (low forage (LF) and high forage (HF)) were applied to each of two genetic lines (control (C) and select (S) genetic merit for milk fat plus protein) giving four contrasting dairy production systems (LFC, LFS, HFC, HFS). Biological efficiency (production and energetic) and environmental efficiency (GWP) were assessed by way of life cycle analysis (LCA), accounting for dairy system inputs and outputs from off-farm production of imported feeds and fertilisers to raw milk leaving the farm gate over a period of seven years. Calculations were conducted using the Intergovernmental Panel on Climate Change (IPCC) methods, with system specific data implemented where possible. Select genetic line under low forage regime (LFS) had the highest gross production and energetic efficiencies (p<0.001). In LFS, milk yields were 56% higher per cow than the lowest ranked HFC system, representing a difference of around 3500kg per cow. Milk solids yield per kg dry matter intake was 18% higher in LFS compared to HFC. High forage with control genetic line required 17% more net energy intake than LFS to produce each kg of milk solids. LFS allocated the highest proportion of net energy to lactating after accounting for body maintenance (p<0.001). Rate of change in efficiency throughout lactation varied significantly (p<0.001) amongst systems, with loss of efficiency minimised in LFS and greatest in HFC. However, LFS involuntary culling rate was significantly higher than other systems (p<0.001). LFS was the most environmentally efficient system and HFC the least (p<0.001), both per unit productivity and per unit total land use. Implementing low forage regime with select genetic line lowered GWP per kg energy corrected milk (ECM) by 24% compared to HFC (p<0.001). GWP of LFC was around 8% lower per kg ECM than HFS (p<0.001). Methane from enteric fermentation contributed the greatest proportion of overall GWP (46-49%) in all systems. However, key factors in the differences amongst systems were higher off-farm CO2 equivalent emissions under low forage, and higher on-farm N2O emissions under high forage regime. HFC produced 91% more nitrous oxide per kg ECM from animal manures compared to LFS, and 65% more N2O from applied manufactured fertilisers (p<0.001). Conversely GWP associated with off-farm production of imported feeds in LFS was 11% higher than in HFC (p<0.001). In low forage systems high gross emissions were offset by high productivity but this was not the case for the high forage systems. Cows of high genetic merit managed under a Low Forage feeding regime had improved production, energetic and environmental efficiencies. However, issues with animal health and fertility raise questions about long term sustainability of the LFS dairy production system, emphasising the importance of examining trade offs between systems.

No description available.

A Agricultura Orgânica no Brasil cresce a taxas superiores a 30 % ao ano, devido, principalmente, a uma maior conscientização dos consumidores, que buscam hábitos alimentares mais saudáveis. Dentre as hortaliças, o tomate orgânico representa uma boa oportunidade de investimento para o produtor. No entanto, não existem recomendações técnicas ou genótipos desenvolvidos exclusivamente para esse sistema de produção, o que dificulta a expansão da área sob manejo orgânico. Diante disso, o presente trabalho teve como objetivo avaliar o desempenho de 11 cultivares de tomate (Avalon, Colibri, HTX – 5415, HTX – 8027, Sahel, San Marzano, San Vito, Júpiter, Raminho, Saladete DRW 3410 e Jane) sob dois sistemas orgânicos distintos em ambiente protegido, de março a outubro de 2004, nos municípios de Ibiúna, SP (experimento I) e Araraquara, SP (experimento II). Os experimentos foram conduzidos em propriedades que produzem tomate orgânico em escala comercial. No experimento I, as plantas foram conduzidas em linhas simples, com uma haste e com poda apical drástica, realizada acima do terceiro racemo. As estufas eram conjugadas, e a irrigação realizada por gotejo, utilizado também para a fertiirrigação com biofertilizantes. O espaçamento adotado foi de 1,5 m entre linhas e 0,35 m entre plantas. No experimento II, as estufas não eram conjugadas, e as plantas foram conduzidas em fileiras duplas, com duas hastes por planta, sem poda apical, no espaçamento de 0,8 m entre linhas e 0,6 m entre plantas. Em ambos os experimentos a densidade de plantio foi de 20 mil plantas por hectare. O delineamento experimental adotado foi em blocos ao acaso, com cinco repetições e dez tratamentos (Avalon, Colbri, HTX – 5415, HTX – 8027, Sahel, San Marzano, San Vito, Júpiter, Raminho e Saladete DRW 3410), para o experimento I, e quatro repetições e oito tratamentos (Avalon, Colbri, HTX – 5415, HTX – 8027, Sahel, San Marzano, San Vito, e Jane) para o experimento II. Considerando as condições em que os experimentos foram desenvolvidos, os resultados permitiram concluir que o híbrido Sahel mostrou o melhor desempenho para rendimento comercial, e para outros componentes da produção nos dois sistemas de condução ao qual foi submetido. No experimento I, destacaram-se, ainda, os híbridos Colibri e Saladete DRW 3410, que não diferiram estatisticamente de ‘Sahel’. Os híbridos, de um modo geral, mostraram melhor desempenho que os cultivares de polinização livre, porém, apenas “Sahel” mostrou maior amplitude adaptativa. No experimento I, conduzido com poda apical drástica, a porcentagem de frutos de melhor cotação comercial foi maior do que no experimento II, sem poda apical. O experimento I, também apresentou período de colheita menor e mais concentrado do que no experimento II. A traça-do-tomateiro revelou-se como fator limitante afetando significativamente o rendimento comercial. / Organic agriculture in Brazil has increased about 30% over the last few years since consumers are seeking for healthier foods, i.e. nutritious and free of pesticide residues. Among vegetable crops organically-grown, tomato constitutes an attractive economic opportunity for growers. However, the lack of information about management practices and cultivars adapted to organic production systems under protected cultivation are pointed out as important constraints that prevents this activity to expand. This work aimed to evaluate the performance of 11 indeterminate tomato cultivars (Avalon, Colibri, HTX – 5415, HTX – 8027, Sahel, San Marzano, San Vito, Júpiter, Raminho Sel. IPA, Saladete DRW 3410 and Jane) under two different organic management systems in unheated plastic greenhouse. Two experiments were carried out under climatically different areas of the State of São Paulo (experiment I, Ibiúna county, and experiment II in Araraquara county), from March to October 2004, in farms that commercially produce organic tomatoes under unheated plastic greenhouses. In both experiments tomato plants were staked. Tomato plants in experiment I were conducted with a single stem and apical bud removed upper 3rd cluster. The experiment was fertigated using with biofertilizers. Plant spacing was 1.5 m between rows and 0.35 m between plants. In experiment II, tomato plants were conducted with two stems without apical pruning. They were planted in double line and spaced 0.8 m between lines and 0.6 m between plants. In both experiments plant density was about 20,000 plants ha-1. Experiments were set up in a randomized complete block design. Experiment I had five replications and ten treatments, and experiment II four replications and eight treatments. Sahel hybrid exhibited an outstanding performance for marketable yield in both organic systems but, in experiment I did not differ statistically from hybrids Colibri and Saladete DRW 3410. Hybrid cultivars, in general, outperformed open pollinated cultivars for the evaluated parameters. Apical pruning had significant effect on the increase of tomato fruits graded as of better commercial acceptance (50-60 mm) and also was associated with concentration of the picking period. It was found that tomato pinworm (Tuta absoluta) constitutes a serious limiting pest for organically-grown tomatoes in both regions where the experiments were set up.

O objetivo deste trabalho foi avaliar a influência de ambientes cobertos com filme de polietileno branco leitoso e diferentes malhas de sombreamento (Termo-refletora –50% e Preta – 50%) nas seguintes variáveis ambientais: irradiância solar global, irradiância fotossinteticamente ativa, temperatura e umidade relativa do ar e evapotranspiração, e de seus respectivos microclimas no crescimento, no desenvolvimento e na qualidade da Gerbera jamesonii (Gérbera). O experimento foi realizado entre o outono e o inverno de 2002, junto à área experimental do Departamento de Ciências Exatas, da E.S.A. "Luiz de Queiroz", Universidade de São Paulo, em Piracicaba, SP. Foi instalado um ambiente protegido, sub-dividido em três partes iguais. Um dos ambientes era coberto apenas pelo plástico leitoso (T1), enquanto os outros dois possuíam, ainda, malhas de sombreamento, que foram instaladas internamente, à altura do pé direito, sendo um com malha termo-refletora (Alumitela) (T2) e outro com malha preta (T3), ambas com 50% de sombreamento, fabricadas pela Solpack Ltda. Os sensores foram instalados no centro de cada ambiente protegido (sub-divisão) e em uma estação meteorológica automatizada, a 100 m do experimento, para coleta dos dados meteorológicos externos. Os ambientes protegidos afetaram os elementos meteorológicos diminuindo a radiação solar, a umidade relativa do ar durante o período diurno e a evapotranspiração das planta de Gérbera e aumentando a temperatura do ar. As transmitâncias médias da radiação solar pelas coberturas (plástico leitoso, plástico leitoso + malha termo-refletora e plástico leitoso + malha preta) foram, respectivamente 23, 11 e 7%. As temperaturas médias diárias do ar dentro dos ambientes protegidos foram cerca de 6 o C maiores no ambiente coberto pelo plástico leitoso e 3 o C maiores nos ambientes cobertos pelo plástico leitoso associado às malhas de sombreamento quando comparadas as temperaturas externas. Os tipos de cobertura, em função do microclima proporcionado, afetaram o desenvolvimento das plantas de Gérbera. O crescimento foi mais rápido sob o plástico leitoso e mais lento sob o plástico leitoso + malha preta. As plantas de Gérbera cultivadas sob os ambientes protegidos cobertos pelo plástico leitoso e pelo plástico leitoso + malha termo-refletora atenderam às exigências quanto ao número de botões florais. Isso não ocorreu no ambiente sob o plástico leitoso + malha preta. Quanto a altura da haste, as plantas cultivadas em ambiente protegido não apresentou valores médios superiores ao mínimo exigido, de 10 cm. Os microclimas proporcionados pelas coberturas constituídas por plástico leitoso e plástico leitoso + termo-refletora promoveram condições adequadas para o cultivo da Gérbera, durante o período entre o outono e o inverno. No entanto não pode-se afirmar que tais condições sejam representativas para todas as estações do ano, recomendando-se estudos futuros comparando-se diferentes materiais de cobertura em diferentes épocas do ano, visando um melhor entendimento do microclima na produção comercial de Gérbera. / The objective of this work was to evaluate the influence of white polyethylene as a greenhouse cover and its association with different shading screens (thermal screen and black screen) on the following environmental elements: incoming solar radiation (Qg), photosynthetically active radiation (PAR), temperature (T), relative humidity (RH) and evapotranspiration (ET) and also to evaluate the effects of the different microclimatic conditions on the growth, development and quality of Gerbera Jamesonii. The experiment was carried out between late Autumn and Winter of 2002 at the experimental area of the Exact Sciences Departament, Agricultural College "Luiz de Queiroz", at the University of São Paulo, in Piracicaba, State of São Paulo, Brazil. A greenhouse was installed, sub-divided into three parts. One of them was covered just with white polyethylene (T1), while the others had, yet, shading screens, that were installed within the greenhouse, being one covered with a thermal screen (Alumitela) (T2) and the other one with a black screen (T3), both with 50% of shading, manufactured by Solpack Ltda. The meteorological sensors were installed in the center of each sub-division of the greenhouse and an automatic weather station was located at 100m from the experimental area, to collect external meteorological data. The covers in the greenhouse affected the microclimate, decreasing Qg, PAR, RH and ET and increasing T. The average transmission of solar radiation by the covers (white polyethylene, white polyethylene + thermal screen and white polyethylene + black screen) were, respectively, 23, 11 and 7%. The mean daily air temperatures within the greenhouse were about 6 o C higher in the white polyethylene and 3 o C higher in the environments covered by white polyethylene associated with the shading screens in comparison to the external temperatures. The types of covers, forming different microclimates, affected the growth and development of Gerbera plants. The growth was faster under the white polyethylene and slower under the white polyethylene associated with black screen. The plants cultivated under the greenhouse covered with white polyethylene and with white polyethylene associated with thermal screen filled the requirements in relation to the number of flower buttons. However, the same was not observed in the environment covered with white polyethylene associated with black screen. About the stem size, all the cultivated plants under all environmental conditions not presented the minimum required value (10 cm). In general, the microclimate influenced by the different covers offered adequated conditions for the cultivation of Gerbera, during autumn and winter periods. However, it is not possible to be sure that these conditions are representative for the whole year stations, being recommended forward studies comparing different cover materials on different periods of the year, searching for a better comprehension of the microclimate influence on the commercial production of Gerbera.

O cultivo protegido em casas de vegetação possibilita produção vegetal de maior qualidade e em qualquer época do ano. A tecnologia tem papel preponderante no controle desses ambientes, embora nem sempre seja satisfatoriamente empregada. Soluções convencionais, como as que utilizam Controladores Lógicos Programáveis, ou sistemas com tecnologia proprietária predominam nas soluções oferecidas. A evolução da tecnologia de comunicação vem possibilitando a difusão do uso da tecnologia de redes de computadores em outras aplicações, as chamadas redes de controle, possibilitando a mudança de paradigmas na concepção de sistemas de monitoramento e controle. Os sistemas com arquitetura centralizada tendem a dar lugar aos com arquitetura distribuída, e o uso da Internet possibilita a supervisão e operação de qualquer lugar. Este trabalho discute a adoção da tecnologia de redes de controle em casas de vegetação, envolvendo aspectos de sua arquitetura, distribuição da inteligência, crescimento incremental, flexibilidade e custos. Ele foi aplicado a uma casa de vegetação do Instituto de Biociências da Universidade de São Paulo, dotada de sistema de automação convencional, para a implantação e avaliação de um sistema experimental baseado na rede de controle com a tecnologia LonWorks®. Utilizaram-se nós inteligentes comercialmente disponíveis e um nó desenvolvido em laboratório. A implementação permitiu a verificação experimental das vantagens e desvantagens da utilização da abordagem distribuída em relação à centralizada. Constatou-se a facilidade de implementação, redução no cabeamento, flexibilidade e interoperabilidade da solução. Contudo, os custos tendem a ser mais elevados na abordagem distribuída, no que se refere às ferramentas de apoio e nós inteligentes. Além da avaliação de aplicação da nova tecnologia, propõe-se uma seqüência de passos a se seguir na migração de um sistema convencional para um sistema de controle distribuído, e apresenta-se a disponibilização do sistema desenvolvido como um Web Lab, que possibilita a realização de experimentos remotamente. / Protected agriculture using greenhouses allows high quality crops and in any time of the year. The technology has a preponderant role in the control of these environments, although no always successfully. Conventional solutions, such as Programmable Logic Controllers, or systems with proprietary technology are predominant. The evolution of the communication technology is making possible the diffusion of computer networks use in other applications: control networks start to awake the interest of both researchers and users, changing the paradigm of monitoring and control systems conception. The traditional systems with centralized architecture tend to be replaced by distributed technology, and the Internet use makes possible the supervision and control from anywhere. This work discusses the control networks technology applied to greenhouses, involving architecture aspects, intelligence distribution, incremental growth, flexibility and costs. For the implementation and assessment of an experimental system based on LonWorks® technology, a greenhouse at Instituto de Biociências at Universidade de São Paulo was used. Off the shelf intelligent nodes were used and an experimental node was developed. The implementation made possible the experimental verification of advantages and disadvantages of the use of distributed and centralized approach. It was evidenced easiness of implementation, cabling reduction, flexibility and interoperability of the solution. However, the costs tend to be raised in the distributed approach, referring to support tools and intelligent nodes. Besides the new technology application evaluation, a step-by-step sequence is proposed for the migration from a conventional system to a control system, and presents a Web Lab system that enables remote experimentation.

The purpose of this dissertation is to assess the current state of climate policy and greenhouse gas (GHG) emission trends in the state Florida and its local governments. The research is guided by three research questions 1) What has been the policy response from state and local governments to the threat of climate change; 2) What were the GHG emission trends from 2000 to 2010 in Florida and its local governments and what were the drivers of change?; and, 3) what were the issues related to the data and methodologies to quantify GHG emissions at the local government level? Policymakers need accurate data and a framework by which to measure progress towards reduction targets and mitigation strategies aimed at reducing GHG emissions. To date, there has not been a comprehensive assessment in Florida despite the proliferation of reduction targets and action planning in state and local governments. Research was conducted to systematically catalogue climate policy at the state and specific actions at the local government level. Actions taken at the local government level included participation in one or more of eight climate networks and completion of a GHG inventory and/or climate action plan. A comprehensive GHG inventory was completed for the state (2000 through 2010) and for all 477 local governments (2000 and 2010). GHG emissions were summarized for total GHG emissions, per capita GHG emissions, per land area GHG emissions, and by sector (i.e., energy, transportation, industrial processes, agriculture, waste, carbon sequestration, and miscellaneous other categories). The ambitious 2007 policies of Governor Crist to curb state GHG emissions floundered once he left office and was replace by the new Governor Rick Scott. It was then left to local governments to respond to the threat of global warming with 117 of 477 local governments pledging to take action (as evidenced through participation in climate action networks). However, only a small minority actually tried to go beyond to complete a GHG inventory and develop a climate action plan. Of these, only two have conducted a follow-up GHG inventory with resultant increases of over 30 percent which falls far short of county-wide reduction targets of 20 percent. GHG emissions from the 39 local governments who undertook GHG inventories found increases in GHG emissions of 10 percent. GHG emissions in the state have increased by 14 percent from 2000 to 2010. In both 2000 and 2010, transportation and electricity consumption were the largest contributors of GHG emissions in both the state and its local governments. Industrial and agricultural emissions were also contributors but these emissions not equally distributed throughout local governments in Florida due to the location of these industries across the state. The rates of change from 2000 to 2010 were not equal in all categories. GHG emission increases were observed in the majority of categories but at different rates; however, reductions were observed in industrial sources and livestock and other agricultural sources. The research identifies drivers of GHG emission change in the state to include population size, Florida gross domestic product (FGDP), land use change, and national energy policies (i.e., natural gas over coal and increased fuel efficiency standards). When assessing methodologies for states and local governments, nine separate GHG methodologies were identified all of which used different approaches and categorical coverage. In addition, the procedures that are used may not be appropriate for the scale of a local jurisdiction due to problems associated with generalizing or averaging emissions data. Data availability at the state level is robust; however, readily-available data at the local government level for certain categories were deemed to be insufficient to avoid highly uncertain assumptions. Review of the completed GHG inventories indicates the use of different approaches makes comparisons between the published GHG emissions impossible. It is recommended that a standardized methodology and data collection framework be used for all local governments for more accurate comparisons and to assess the impacts of policy at a local government scale. While the local government GHG inventory required the use of some uncertain assumptions due to data limitations, such a framework was developed for this dissertation. The framework could be refined with more accurate data for future inventories and could also be adapted for other states.

Peat soils store a large fraction of the global soil carbon (C) pool and comprise 95% of wetland C stocks. They also have the capability to produce and release significant amounts of greenhouse gasses (CO2, CH4) into the atmosphere. Most studies of wetland soil C and gas flux dynamics have been done in expansive peatlands in northern boreal and subarctic biomes. However, wetlands in temperate and tropical climates are vastly understudied despite accounting for more than 20% of the global peatland C stock and storing large amounts of biogenic gasses Although studies investigating greenhouse gas dynamics from peatlands have increased during the last decade, the spatial and temporal distribution of these gases still remains highly uncertain, mainly due to the limitations in terms of spatial and temporal resolution and invasive nature of most methods traditionally used. This thesis combines a series of field and laboratory studies at several sites in the Greater Everglades as examples to show the potential of hydrogeophysical methods to better understand: 1) the belowground C distribution and overall contribution to the global C stocks of certain wetlands (Chapter 2); and 2) the spatial and temporal variability in both C accumulation and releases from peat soil monoliths from several wetland sites in the Greater Everglades (Chapter 3 and 4). To estimate belowground C in the field, I used a combination of indirect non-invasive geophysical methods (GPR), aerial imagery, and direct measurements (coring) to estimate the contribution of subtropical depressional wetlands to the total C stock of pine flatwoods landscape at the Disney Wilderness Preserve (DWP, Orlando, FL). Three-dimensional (3D) GPR surveys were used to define the thickness of stratigraphic layers from the wetland surface to the mineral soil interface within depressional wetlands. Depth-profile cores in conjunction with C core analysis were utilized to visually confirm depths of each interface and estimate changes in soil C content with depth and were ultimately used to estimate total peat volume and C stock for each depressional wetland. Aerial photographs were used to develop a relationship between surface area and total wetland C stock, that were applied to estimate total landscape C stock of all depressional wetlands throughout the entire preserve. Additionally, low-frequency GPR surveys were conducted to image the stratigraphy underneath the peat basin of depressional wetlands to depict lithological controls on the formational processes of depressional wetlands at the DWP. Spatial and temporal variability in biogenic greenhouse gas (i.e. methane and carbon dioxide) production and release were investigated at the laboratory scale. Two 38 liter (0.5 m x 0.23 m x 0.3 m) peat monoliths from two different wetland ecosystems in central Florida (sawgrass peatland and a wet prairie) were compared in order to understand whether changes in matrix properties influence gas dynamics in a controlled environment (i.e. constant temperature). Gas content variability (i.e. build-up and release) within the peat matrix was estimated using a series of high frequency (1.2 GHz) GPR transects along each sample about three times a week. An array of gas traps (eight per sample) fitted with time-lapse cameras were also used in order to constrain GPR measurements and capture gas releases at 15-minute intervals. Gas chromatography was performed on gas samples extracted from the traps to determine CH4 and CO2 content. Also, at the lab scale, temporal variability in biogenic gas accumulation and release was investigated in a large 0.073 m3 peat monolith from the Blue Cypress Preserve in central Florida. An autonomous rail system was constructed in order to estimate gas content variability (i.e. build-up and release) within the peat matrix using a series of continuous GPR transects along the sample. This system ran virtually nonstop using high frequency (1.2 GHz) antennas. GPR measurements were again constrained with an array of gas traps (6) fitted with time-lapse cameras and gas chromatography. The aim of this study is to better constrain temporal scale, and better understand the heterogeneous nature (both in time and space) of gas releases from peat soils. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection