Reducing the rates of greenhouse gas (GHG) emissions is critical in combatting global climate change. Carbon dioxide (CO2) and methane (CH4) are the two most important carbon-based GHGs, for their atmospheric warming potential. Wetlands such as the Florida Everglades play major roles in the global carbon cycle, as varying hydrologic conditions lead to differential production rates of these two GHGs. This study measured CO2 and CH4 emissions in a re-created Everglades ridge-and-slough wetland, where water levels were controlled to reflect natural flood patterns. As expected, lower elevations were flooded longer and produced more CH4, while higher elevations produced more CO2. Since CH4 has a relatively high global warming potential, CO2 production would need to be 70 times that of CH4, to balance their GHG output. The average ratio of CO2 to CH4 across elevations was 22.0 (mol:mol), indicating that future water management within wetlands should consider GHG production potential.

Orientador: Denis Miguel Roston / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-24T11:06:36Z (GMT). No. of bitstreams: 1 Silva_EduMaxda_D.pdf: 5550802 bytes, checksum: 9ab6a662fd86349f1faa976169d785c5 (MD5) Previous issue date: 2013 / Resumo: A pecuária moderna enfrenta grandes desafios para estabelecer o equilíbrio das estreitas relações entre: produção intensiva, saúde animal e sustentabilidade ambiental. Contudo, ainda existe uma grande lacuna entre a produtividade animal e o meio ambiente.Os prejuízos ambientais podem tornar-se ainda maiores quando esses resíduos orgânicos são arrastados ou lançados diretamente nos cursos d¿água, fato que pode reduzir de forma drástica os teores de oxigênio dos corpos hídricos receptores e provocar a eutrofização de rios, riachos, lagos e lagoas. Os dejetos também podem causar contaminação do solo, do ar e se dispostos ao lado das instalações, podem contribuir para a proliferação de moscas, roedores e tornarem-se repugnantes, devido ao aspecto e odor. Neste trabalho avaliou-se, de Julho/2012 a Agosto/2013, a eficiência do tratamento dos efluentes líquidos da Unidade Educativa de produção (UEP) - animais de grande porte - bovinocultura de leite do IFSULDEMINAS - Campus Inconfidentes. O sistema de tratamento era composto de unidades de retenção de sólidos, reator anaeróbio compartimentado e "wetland" construído. As eficiências de redução dos parâmetros analisados foram: Sólidos Totais (ST) - 95 %, Sólidos Dissolvidos Totais (SDT) - 95%, Sólidos Sedimentáveis (SSed.) - 100%, Demanda Química de Oxigênio (DQO) - 99%, Demanda Bioquímica de Oxigênio (DBO) - 97%, Nitrogênio Amoniacal - 93%, Nitrato (NO3-) - 88%, Nitrogênio Total Kjeldahl (NTK) - 96% e Fósforo (P) - 93%. A partir dos resultados obtidos, pode-se recomendar o sistema proposto como alternativa tecnológica para tratamento de resíduos líquidos de instalações e equipamentos de bovinocultura de leite / Abstract: The modern dairy production faces big challenges to balancing the close relations between intensive production, animal health and environmental sustainability. The increase in the number of concentrated animal feeding operations, mainly dairy production, may increase proportionally the amount of waste produced, which can impact severely the environment especially when there are no treatment systems for those organic wastes. Environmental damage may become even greater when the organic wastes are dragged directly into waterways, which greatly reduces the levels of oxygen causing eutrophication of rivers, streams, lakes and ponds. The waste can also cause contamination of soil, air and disposed adjacent to the premises, may contribute to the proliferation of flies, rodents and become loathsome because of appearance and unpleasant odor. This work proposed a treatment plant to treat waste from dairy production composed by retention solids units, anaerobic baffled reactor and constructed wetland. The system was evaluated from July/ 2012 to August/2013. The results obtained regarding system efficiency in removal/reduced the analyzed parameters were: Total Solids (TS) - 95%, Total Dissolved Solids - 95%, Settling Solids - 100%, Chemical Oxygen Demand (COD) - 99%, Biochemical Oxygen Demand (BOD) - 97%, Ammonia Nitrogen - 93%, Nitrate - 88%, Total Kjeldahl Nitrogen (TKN) - 96% and Phosphorus (P) - 93%. According to the results, the system proposed may be considered as a technological alternative to treat liquid waste from facilities and equipments from dairy production / Doutorado / Agua e Solo / Doutor em Engenharia Agrícola

Body size is a fundamental structural characteristic of organisms, determining critical life history and physiological traits, and influencing population dynamics, community structure, and ecosystem function. For my dissertation, I focused on effects of body size on habitat use and diet of important coastal fish predators, as well as their influence on faunal communities in Bahamian wetlands. First, using acoustic telemetry and stable isotope analysis, I identified high variability in movement patterns and habitat use among individuals within a gray snapper (Lutjanus griseus) and schoolmaster snapper (L. apodus) population. This intrapopulation variation was not explained by body size, but by individual behavior in habitat use. Isotope values differed between individuals that moved further distances and individuals that stayed close to their home sites, suggesting movement differences were related to specific patterns of foraging behavior. Subsequently, while investigating diet of schoolmaster snapper over a two-year period using stomach content and stable isotope analyses, I also found intrapopulation diet variation, mostly explained by differences in size class, individual behavior and temporal variability. I then developed a hypothesis-testing framework examining intrapopulation niche variation between size classes using stable isotopes. This framework can serve as baseline to categorize taxonomic or functional groupings into specific niche shift scenarios, as well as to help elucidate underlying mechanisms causing niche shifts in certain size classes. Finally, I examined the effect of different-sized fish predators on epifaunal community structure in shallow seagrass beds using exclusion experiments at two spatial scales. Overall, I found that predator effects were rather weak, with predator size and spatial scale having no impact on the community. Yet, I also found some evidence of strong interactions on particular common snapper prey. As Bahamian wetlands are increasingly threatened by human activities (e.g., overexploitation, habitat degradation), an enhanced knowledge of the ecology of organisms inhabiting these systems is crucial for developing appropriate conservation and management strategies. My dissertation research contributed to this effort by providing critical information about the resource use of important Bahamian fish predators, as well as their effect on faunal seagrass communities.

Black carbon (BC), the incomplete combustion product from biomass and fossil fuel burning, is ubiquitously found in soils, sediments, ice, water and atmosphere. Because of its polyaromatic molecular characteristic, BC is believed to contribute significantly to the global carbon budget as a slow-cycling, refractory carbon pool. However, the mass balance between global BC generation and accumulation does not match, suggesting a removal mechanism of BC to the active carbon pool, most probable in a dissolved form. The presence of BC in waters as part of the dissolved organic matter (DOM) pool was recently confirmed via ultrahigh resolution mass spectrometry, and dissolved black carbon (DBC), a degradation product of charcoal, was found in marine and coastal environments. However, information on the loadings of DBC in freshwater environments and its global riverine flux from terrestrial systems to the oceans remained unclear. The main objectives of this study were to quantify DBC in diverse aquatic ecosystems and to determine its environmental dynamics. Surface water samples were collected from aquatic environments with a spatially significant global distribution, and DBC concentrations were determined by a chemical oxidation method coupled with HPLC detection. While it was clear that biomass burning was the main sources of BC, the translocation mechanism of BC to the dissolved phase was not well understood. Data from the regional studies and the developed global model revealed a strong positive correlation between DBC and dissolved organic carbon (DOC) dynamics, indicating a co-generation and co-translocation between soil OC and BC. In addition, a DOC-assistant DBC translocation mechanism was identified. Taking advantage of the DOC-DBC correlation model, a global riverine DBC flux to oceans on the order of 26.5 Mt C yr-1 (1 Mt = 1012 g) was determined, accounting for 10.6% of the global DOC flux. The results not only indicated that DOC was an important environmental intermediate for BC transfer and storage, but also provided an estimate of a major missing link in the global BC budget. The ever increasing DBC export caused by global warming will change the marine DOM quality and may have important consequences for carbon cycling in marine ecosystem.

This curriculum guide is for grades four through six. It examines how wetlands, wildlife, and people interact and depend upon each other. The San Jacinto Valley wetland area is used as an example of wetland habitat destruction from population pressures that have changed the natural landscape. It is also used as an example of what habitat reconstruction can do to restore vital habitats. Through student contact with the wetlands increased awareness of the fragile interrelationships between the physical and biological components of a wetland habitat is gained. Students can use ecological themes to help them assimilate collected and given data into logical cohesive ideas, laying the ground work for developing an environmental action project.

The Florida Everglades ecosystem is experiencing increasing threats from anthropogenic modification of water flow, spread of invasive species, sea level rise (SLR), and more frequent and/or intense hurricanes. Restoration efforts aimed at rehabilitating these ongoing and future disturbances are currently underway through the implementation of the Comprehensive Everglades Restoration Plan (CERP). Efficacy of these restoration activities can be further improved with accurate and site-specific information on the current state of the coastal wetland habitats. In order to produce such assessments, digital datasets of the appropriate accuracy and scale are needed. These datasets include orthoimagery to delineate wetland areas and map vegetation cover as well as accurate 3-dimensional (3-D) models to characterize hydrology, physiochemistry, and habitat vulnerability. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

Lewisville Lake Environmental Learning Area (LLELA) is an 809-hectare property in Denton County, TX. A study of the vegetation community identified 466 species in 104 families, with 25% of the species from only two families, Asteraceae and Poaceae. The property demonstrates the characteristics of an early successional community, dominated by weedy species. Prairie communities are dominated by Johnson grass and ragweed, with climax tall grass prairie communities only in areas that have been planted with native grass seed. Forest communities are similarly in an early successional stage, dominated by the hackberry-elm-ash alliance, with small remnants of native Cross Timbers found in isolated patches. Species richness and diversity were highest in the forests and lowest in the wetlands; evenness, though not different across ecosystems, demonstrated a strong seasonal component. The species list was compared with previously reported lists for Denton County, and 256 species identified had not been previously reported for the county. A wetland restoration study was conducted to determine if there was a difference in survival and growth between potted transplants with intact root systems and bare-root transplants. Two different mesh sizes were used for protection, and the success of the different caging was evaluated. Of eight species, only four survived through the second growing season. There was no significant difference in the success of the propagule types for Sagittaria latifolia. The treatments planted with intact root systems showed significantly higher growth and reproduction than the bare-root treatments for Eleocharis quadrangulata, Heteranthera dubia, and Vallisneria americana. There was no survival recorded in the coarse mesh cages, likely due to the presence of crayfish that are able to get through the coarser mesh and feed on the transplants.

Constructed wetland is one of ways of domestic wastewater treatment that allows reuse of treated water. The thesis acquainted with run principles, with a design for a family house, that includes different solutions of technologic parts with advice for a reliable run and theoretical financial costs.

The thesis is focused on the options of stream restoration with its surroundings in a place of nature area „Na Loukách“ in town district „Mokrá Hora“. The thesis also describes current condition and development of the land use of focused area. There is junction of three creeks in the focused area. In part of this area there is not original depth of ground water surface due to adjustment of Rakovec creek. This thesis introduces three options of increasing depth of ground water surface. Evaluation of the current condition of creeks was performed by the HEM method. Hydraulic calculations were made in HEC-RAS program.

Les teneurs en pesticides mesurées dans les eaux de drainage agricole peuvent atteindre 10 µg/L voire 395 µg/L. En Lorraine, des Zones Tampons Végétalisées Agricoles (ZTVA) ont été installées en sortie de drains agricoles afin de limiter le transfert de ces eaux de drainage vers la rivière. L’objectif de ce travail était d’évaluer l’influence de l’hydraulique sur l’épuration des pesticides et métabolites en phases dissoute et particulaire des eaux de drainage, en discriminant les processus associés. Pour cela, une approche multi-échelle intégrant des expérimentations au laboratoire en batch et en bacs pilotes ainsi qu’un monitoring pluriannuel de deux ZTVA sur le terrain (un fossé et une mare) a été mise en place. Les expériences de traçages in-situ ont montré que quel que soit le débit, la ZTVA peut être divisée en différentes zones hydrauliques : un chenal principal et des zones isolées, qui se comportent différemment vis-à-vis de l’épuration. Les efficacités d’épuration dans les deux ZTVA varient de (i) -1176% à 96% pour les pesticides dissous, (ii) -20% à 3% pour les métabolites (chloroacétanilides) à l’état dissous, et (iii) -580% à 79% pour les pesticides sous forme particulaire. L’adsorption sur les sédiments permet l’épuration des pesticides à l’état dissous dont le coefficient d’adsorption (Koc) varie de 364 à 1424 L/g (entre 7 et 65% d’épuration), et est favorisé au sein des zones isolées. Cependant, ce processus est réversible et la désorption peut expliquer les efficacités négatives mesurées sur le terrain. Par ailleurs, les pesticides plus hydrophiles (Koc varie de 54 à 401 L/g) et les métabolites (Koc varie de 0 à 0.77 L/g) sont peu épurés (entre -20 et 8% d’épuration). Enfin, les pesticides entrant dans la ZTVA sous forme particulaire sont épurés via la sédimentation des matières en suspension, plus importante dans les zones isolées que le chenal principal. Ce processus est réversible, pouvant conduire à la resuspension des sédiments. Par ailleurs, les débits entrants vont fluctuer au cours de l’année, pouvant entrainer une variation de l’épuration des pesticides. En effet, les études en batch et en bacs pilotes ont permis de souligner l’influence de l’hydrodynamique (débits, etc) sur l’épuration des pesticides à l’état dissous. Ces ZTVA jouent donc un rôle de puits (adsorption, sédimentation) et de source (désorption, resuspension) vis-à-vis de certains pesticides à l’état dissous ou particulaire, en lien avec l’hydrodynamique de la ZTVA / Pesticides amounts measured in agricultural drained water can reach 10 µg/L up to 395 µg/L. In Lorraine, Constructed Wetlands (CW) were set up between drained fields and the river to limit pesticide release. The aim of this study was to evaluate the influence of hydraulic on the mitigation of pesticides and metabolites in both dissolved and particulate phases of drained water, by discriminating associated processes. To do so, a multi-scale approach was performed by integrating both laboratory experiments, such as batch and dynamic conditions in pilots, and a plurennial monitoring of two different ZTVA (ditch and pond). In-situ tracing experiments highlighted that the volume of CW was not homogeneous, independently of the flow rate. CW are divided in two hydraulic zones: a main channel and isolated areas. Moreover, these two zones behave differently regarding pesticides mitigation. Annual mitigation efficiency in both of the CW studied, vary between (i) -1176 % and 96 % for dissolved pesticides, (ii) -20 % and 3 % for dissolved metabolites (chloroacetanilides), and from (iii) -580 % to 79 % for particulate pesticides. Adsorption on sediments allows the mitigation of dissolved pesticides whose adsorption coefficient (Koc) varied from 364 to 1424 L/g (mitigation ranging from 7 to 65 %), and occurred mainly in isolated areas. However, this process is reversible and desorption can explain negative efficiency measured on the field. Additionally, hydrophilic pesticides (Koc between 54 and 401 L/g) and metabolites (Koc between 0 and 0.77 L/g) are few or not mitigated (mitigation ranging from -20 and 8 %). Finally, pesticides entering CW under particulate phase are mitigated through sedimentation of total suspended solids, higher in isolated areas than in main channel. This process is also reversible, leading to sediments resuspension. Otherwise, inlet flow rates vary throughout the year, which could allow a variation of pesticide mitigation. Indeed, batch and pilots studies highlighted the influence of hydrodynamic (flow rate, etc) on mitigation of dissolved pesticides. CW act as a sink (adsorption and sedimentation) and a source (desorption and resuspension) towards specific dissolved or particulate pesticides and related to hydrodynamic of CW