Thesis (M. A.)--University of North Carolina at Greensboro, 2006. / Title from PDF title page screen. Advisor: Roy S. Stine; submitted to the Dept. of Geography. Includes bibliographical references (p. 60-65)

Thesis (M.S.)--Ohio State University, 1987. / Includes bibliographical references (leaves 65-70).

Thesis (M.Sc.)--York University, 2004. Graduate Programme in Geography. / Typescript. Includes bibliographical references (leaves 196-210). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11810

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Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves [135]-139). Also available on the Internet.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 78-86). Also available via the Internet.

Pacific Northwest coastal wetland extent has been significantly reduced due to development. To understand the effects of land use change on carbon cycling in coastal wetlands, we compared soil carbon dynamics in restored, disturbed (by diking or draining), and reference wetlands in both freshwater and saline conditions in Coos Bay, Oregon. We quantified soil carbon pools, measured in situ fluxes of methane (CH4) and carbon dioxide (CO2), and estimated sediment deposition and carbon sequestration rates. We found that land use change influences carbon cycling and storage in coastal wetlands. The disturbed marshes have likely lost all their organic material after draining or diking, except for a shallow A horizon. The restored marsh in situ CH4 and CO2 fluxes were intermediate between the disturbed and reference marshes. Generally, restored marshes showed a partial return of carbon storage functions, or an indication that reference level functions may be achieved over time.

Submitted by LIVIA FREITAS (livia.freitas@ufba.br) on 2014-07-28T18:06:08Z No. of bitstreams: 1 DISSERTAÇÃO FINAL.pdf: 2930897 bytes, checksum: 9239e65ba6c9a32c9c27954d984b412d (MD5) / Approved for entry into archive by LIVIA FREITAS (livia.freitas@ufba.br) on 2014-07-28T18:06:21Z (GMT) No. of bitstreams: 1 DISSERTAÇÃO FINAL.pdf: 2930897 bytes, checksum: 9239e65ba6c9a32c9c27954d984b412d (MD5) / Made available in DSpace on 2014-07-28T18:06:22Z (GMT). No. of bitstreams: 1 DISSERTAÇÃO FINAL.pdf: 2930897 bytes, checksum: 9239e65ba6c9a32c9c27954d984b412d (MD5) / Um sistema de tratamento de esgoto sanitário, em escala real, composto por reator UASB seguido de wetlands construídos de fluxo horizontal subsuperficial foi avaliado quanto ao comportamento, eficiências de remoção de poluentes e seus aspectos operacionais. O processo foi estudado em duas etapas caracterizadas pela presença e ausência da recirculação do efluente final em duas unidades de wetlands construídos plantadas com diferentes espécies de macrófitas. As faixas de valores das concentrações efluentes dos parâmetros analisados foram: matéria orgânica medida como DQO, 26 a 96 mgO2/L; Sólidos em Suspensão Totais, 2 a 29 mg/L; Sólidos em Suspensão Voláteis, 0 a 27 mg/L; Nitrogênio Total Kjedhal, 17,9 a 72,8 mg/L; nitrogênio amoniacal, 15,4 e 58,8 mg/L; P-PO43-: 3,9 a 9,4 mg/L; fósforo total, 5,6 a 8,5 mg/L; Coliformes Termotolerantes: 104 a 105 NMP/100mL e Coliformes Totais: 105 a 106 NMP/100mL. A aplicação do teste não paramétrico de Wilcoxon-Mann-Whitney em nível de significância igual a 5% mostrou que não houve diferença significativa entre o desempenho de remoção de poluentes durante as duas etapas da pesquisa, nem entre as unidades plantadas com macrófitas distintas. O presente estudo mostrou que wetlands construídos de fluxo horizontal subsuperficial tratando o efluente de reator UASB são capazes de atender a maioria dos padrões de lançamento preconizados na legislação ambiental vigente. O estudo, também, permitiu concluir que há necessidade de uma operação intensa e contínua para se garantir condições adequadas de funcionamento de tais sistemas. / A wastewater treatment system in real scale, consisting of UASB reactor followed by constructed wetlands of subsurface horizontal flow was evaluated. The process was studied in two stages characterized by the presence and absence of recirculation of final effluent into two units planted with different macrophytes. The ranges of values of the effluent concentrations of the analyzed parameters were : organic matter measured as COD, 26-96 mgO2.L-1, total suspended solids: 2-29 mg.L-1, volatile suspended solids: 0-27 mg.L-1, total nitrogen: 17.9 to 72.8 mgN.L-1, ammonia nitrogen: 15.4 and 58.8 mg NH3-N.L-1, soluble phosphorus 3.9 to 9.4 mg PO43--P.L-1, thermotolerant coliforms: 104-105 NMP/100mL and total coliforms: 105-106 NMP/100mL. The application of non-parametric Wilcoxon-Mann-Whitney test at a significance level of 5% showed no significant difference between the performance of pollutant removal during the two stages of the research or units planted with different macrophytes. The present study showed that constructed wetlands of subsurface horizontal flow treating the effluent from UASB reactors are able to meet most of the standards recommended in Brazilian environmental regulations. The study also concluded that there is need for intensive and continuous operation to ensure proper conditions of operation of such systems.

What is a wetland? What does this category imply? Is it different from a land which is wet? This thesis addresses these questions through a study of environmental conflicts in two protected wetlands in Agro Pontino, Italy. This region, 70 kilometres south of Rome, was affected between the 1920s and the 1930s, by one of the most important operations of land reclamation of that time, conducted by the fascist regime which drained the largest marshland in Italy, i.e. the Pontine Marshes. Based on fieldwork in protected wetlands considered as the remnants of the Pontine Marshes, the thesis includes the analysis of various original case studies, such as the activities of Environmental Interpretation and farming, among others. Moreover, it discloses archive records that cast new light on the social and environmental context of the Pontine Marshes. The thesis explores how farmers and conservationists relate with a particular kind of environment, namely wetlands in conservation areas; their relations with non-humans; their different reading of the history and evolution of these landscapes and the connections between these aspects and the conflicts affecting these areas. These conflicts concern different ideas of what a wetland should be and the appropriate practices aimed at implementing those ideas. The research, which is influenced by the work of Tim Ingold, challenges the established notion of wetland, based on a topographic and spatial understanding of the world, suggesting that wetlands are patterns characterized by movements, tasks and activities: entanglements of innumerable life-lines traced by human and non-human beings in the accomplishment of their tasks. It is in this entanglement which politics emerge, conflicts flourish and life goes on. Accordingly, I argue that following these life-lines and exploring what I call the geography of the meshwork, can disclose new interpretative perspectives to understand environmental conflicts.

abstract: Cities can be sources of nitrate to downstream ecosystems resulting in eutrophication, harmful algal blooms, and hypoxia that can have negative impacts on economies and human health. One potential solution to this problem is to increase nitrate removal in cities by providing locations where denitrification¬— a microbial process in which nitrate is reduced to N2 gas permanently removing nitrate from systems— can occur. Accidental urban wetlands– wetlands that results from human activities, but are not designed or managed for any specific outcome¬– are one such feature in the urban landscape that could help mitigate nitrate pollution through denitrification. The overarching question of this dissertation is: how do hydrology, soil conditions, and plant patches affect patterns of denitrification in accidental urban wetlands? To answer this question, I took a three-pronged approach using a combination of field and greenhouse studies. First, I examined drivers of broad patterns of denitrification in accidental urban wetlands. Second, I used a field study to test if plant traits influence denitrification indirectly by modifying soil resources. Finally, I examined how species richness and interactions between species influence nitrate retention and patterns of denitrification using both a field study and greenhouse experiment. Hydroperiod of accidental urban wetlands mediated patterns of denitrification in response to monsoon floods and plant patches. Specifically, ephemeral wetlands had patterns of denitrification that were largely unexplained by monsoon floods or plant patches, which are common drivers of patterns of denitrification in non-urban wetlands. Several plant traits including belowground biomass, above- and belowground tissue chemistry and rooting depth influenced denitrification indirectly by changing soil organic matter or soil nitrate. However, several other plant traits also had significant direct relationships with denitrification, (i.e. not through the hypothesized indirect relationships through soil organic matter or soil nitrate). This means these plant traits were affecting another aspect of soil conditions not included in the analysis, highlighting the need to improve our understanding of how plant traits influence denitrification. Finally, increasing species richness did not increase nitrate retention or denitrification, but rather individual species had the greatest effects on nitrate retention and denitrification. / Dissertation/Thesis / Doctoral Dissertation Biology 2016