FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Este trabalho teve como objetivo avaliar as variÃveis fÃsicas, quÃmicas, biolÃgicas e a ocorrÃncia tanto da toxicidade aguda como da diversidade e quantidade da biomassa fitoplanctÃnica, ao longo de um ciclo climÃtico, na sub-bacia B1, integrante da bacia hidrogrÃfica do rio CocÃ, Fortaleza â CE. A amostragem ocorreu em frequÃncia mensal para os quatorzes pontos de coleta, no perÃodo de setembro de 2010 a abril de 2011, com a exceÃÃo de fevereiro de 2011, quando nÃo foi possÃvel executÃ-la. Os parÃmetros analisados, temperatura, transparÃncia, pH, turbidez, cor verdadeira, condutividade elÃtrica, sÃlidos e fraÃÃes, Ãleos e graxas, alcalinidade e fraÃÃes, dureza e fraÃÃes, cÃlcio, magnÃsio, oxigÃnio dissolvido, cloretos, DBO5, DQO, fÃsforo e fraÃÃes, sulfato, sulfeto, ferro total, clorofila âaâ, amÃnia total, nitrito, nitrato, nitrogÃnio orgÃnico, nitrogÃnio total kjeldahl, Coliformes Termotolerantes, Escherichia coli, toxicidade aguda, identificaÃÃo e contagem do fitoplÃncton, indicaram variaÃÃo no espaÃo devido aos diferentes impactos antrÃpicos sofridos. Toda a sub-bacia B1 encontra-se eutrofizada, principalmente devido ao lanÃamento de matÃria orgÃnica e nutrientes, especialmente o fÃsforo. Apesar do perÃodo monitorado apresentar quadra invernosa atÃpica, Ãndices pluviomÃtricos acima da mÃdia, isso nÃo foi suficiente para ocasionar a diluiÃÃo e possÃvel enquadramento legal, principalmente, com relaÃÃo aos teores de DBO5, Ãleos e graxas, fÃsforo total e Coliformes Termotolerantes. Na maior parte do monitoramento, a sub-bacia B1 apresentou indÃcios de toxicidade; somente no mÃs de abril foi evidenciada toxicidade aguda, o que pode ser devido à ocorrÃncia de chuvas no dia anterior à coleta. Com relaÃÃo à diversidade fitoplanctÃnica, no perÃodo seco houve a ocorrÃncia de 58 tÃxons e 7 classes; na quadra invernosa, houve o aumento da diversidade, 65 tÃxons e 10 classes. As classes que lideram os dois perÃodos sÃo: Chlorophyceae e Cyanobacteria. No entanto, Aphanocapsa spp à a classe dominante para os dois perÃodos, em todos os pontos monitorados, apresentando valores superiores ao limite estabelecido pela legislaÃÃo vigente, o que se torna preocupante, pois se trata de uma espÃcie potencialmente tÃxica. / This study aimed to evaluate the physical, chemical, biological, and the occurrence of both the acute toxicity and the diversity and quantity of phytoplankton biomass, along a climatic cycle, on sub-basin B1, a member of the Cocà River basin, Fortaleza - CE. The sampling occurred monthly on fourteen collecting points in the period of September 2010 to April 2011, in the exception of February 2011 that could not run it. With the parameters analyzed, temperature, transparency, pH, turbidity, true color, conductivity electrical, solids and fractions, calcium, magnesium, dissolved oxygen, chlorides, BOD5, QOD, phosphorus and fractions, sulfate, sulfide, total iron, Chlorophyll "a", total ammonia, nitrite, nitrate, organic nitrogen, total kjeldahl nitrogen, thermotolerant coliforms, Escherichia coli, acute toxicity, identification and enumeration of phytoplankton, have indicated variation in space due to different human impacts suffered. All the sub-basin B1 is found eutrophic, mainly due to the release of organic matter and nutrients, especially phosphorus. Although the monitored period to present court wintry atypical, with above the average rainfall, it was not enough to cause the dilution and possible legal framework, mainly at the oil and grease, total phosphorus and thermotolerant coliforms. In most of the monitoring, the sub-basin B1 showed signs of toxicity; only in the month of April was observed acute toxicity, which may be due to the rainfall some days before collection. With respect to phytoplanktonic diversity during the dry season to occurred the presence of 58 taxon and 7 classes and at court wintry, diversity increases to taxon 65 and 10 classes. The classes who lead both periods are: Chlorophyceae e Cyanobacteria. However, Aphanocapsa spp is the dominant class in both periods, at all points monitored, with values above the limit set by law, which is very worrying, because it is a potentially toxic species.

This study responds to the effect that current food production has on the natural environment, by researching urban systems and ecosystems. In reaction to the findings, a new food production system and the urban buying and retail culture are investigated. A food market and hydroponic production building is designed to serve as an alternative to the supermarket and conventional food production. AFRIKAANS : Hierdie studie reageer op die uitwerking wat huidige voedsel produksie op die natuurlike omgewing het, deur stedelike stelsels en ekostelsels te bestudeer. In reaksie op die bevindings word ‘n nuwe voedsel produksie stelsel en die stedelike koop-enverkoop- kultuur ondersoek. ‘n Varsprodukte mark en hidroponiese produksie-gebou word ontwerp om ‘n alternatief te bied vir die supermark en konvensionele voedselproduksie. / Hierdie studie reageer op die uitwerking wat huidige voedsel produksie op die natuurlike omgewing het, deur stedelike stelsels en ekostelsels te bestudeer. In reaksie op die bevindings word ‘n nuwe voedsel produksie stelsel en die stedelike koop-en verkoop- kultuur ondersoek. ‘n Varsproduktemark en hidroponiese produksie-gebou word ontwerp om ‘n alternatief te bied vir die supermark en konvensionele voedselproduksie. / Dissertation (MArch(Prof))--University of Pretoria, 2011. / Architecture / unrestricted

The 2014 Agricultural Act (Economic Research Division) (aka: The Farm Bill) was an important limelight shone on the issue of access to healthy foods, food education and the correlation between an increasingly unhealthy population and proximity to fresh, healthy food. Further legislation such as the Urban Agricultural Production Act of 2017 has been introduced to leverage the Farm Bill's financial incentives to promote urban agricultural programs and transform vacant land into agricultural use. Specifically, this has become increasingly common in many lower income and disadvantaged communities affected by a lack of access to fresh food stores. Additionally, in response many public schools have pro-actively sought funds to transform their schoolyards into gardens and teaching classrooms (Gamson) in order to provide food literacy and education however, this practice remains the exception. Many children still face a lack of healthy food options or the availability of any fresh food outside of their school environment. What if the standard education facility could be used as a tool to confront not only the architecture of the learning space, but a school-as-ecosystem, representing a neighborhood catalyst to teach through action – addressing comprehensive global issues brought on by food desert environments and a child's perspective about their own health? This thesis explores the possibility of casting the urban ecological net wide- envisioning a timescale for transforming public spaces and school grounds using green infrastructure practices, biological remediation, planning for changes in transportation technology and the expectations of a public education and child's perception about their environment. Emphasizing a broad focus on all of the potential sites for food production in the city (including the school, schoolyard and what they represent to the community), surfaces a multi-functioning methodology encompassing community identity, amenity, ecology, infrastructure and beauty envisions what could become of urban areas in the future. The primary goal is to educate future generations in the value of the food network and to give them the kind of direct hands-on experience that educators emphasize while concurrently nourishing urban communities through development of a project carried out in common, one that has health benefits for the population, that engenders a sense of long-term pride, and that empowers people to make change in their environment, even in modest or temporary ways. The idea that school design can encourage and facilitate, hinder and inhibit behaviors at school, and the architectural symbolism of schools can have a profoundly wider impact on children and their behaviors in and outside of school (Tucker). There is a significant psychological difference in learning about the environment, for the environment and in the environment (Malone). Creating public space focused on individual learning and the physical and mental health of the individual aims to balance the scales of social economic injustices. It is going to take every effort from the hyper-localized to city-wide and even regional scales to make significant urban changes to create a taxonomy of spaces to support the growth of our cities while simultaneously educating young minds on the value of understanding our ecological relationship to the city and surrounding environment. / Master of Science / The 2014 Agricultural Act (Economic Research Division) (aka: The Farm Bill) was an important limelight shone on the issue of access to healthy foods, food education and the correlation between an increasingly unhealthy population and proximity to fresh, healthy food. Further legislation such as the Urban Agricultural Production Act of 2017 has been introduced to leverage the Farm Bill’s financial incentives to promote urban agricultural programs and transform vacant land into agricultural use. Specifically, this has become increasingly common in many lower income and disadvantaged communities affected by a lack of access to fresh food stores. Additionally, in response many public schools have pro-actively sought funds to transform their schoolyards into gardens and teaching classrooms (Gamson) in order to provide food literacy and education however, this practice remains the exception. Many children still face a lack of healthy food options or the availability of any fresh food outside of their school environment. What if the standard education facility could be used as a tool to confront not only the architecture of the learning space, but a school-as-ecosystem, representing a neighborhood catalyst to teach through action – addressing comprehensive global issues brought on by food desert environments and a child’s perspective about their own health? This thesis explores the possibility of casting the urban ecological net wide- envisioning a timescale for transforming public spaces and school grounds using green infrastructure practices, biological remediation, planning for changes in transportation technology and the expectations of a public education and child’s perception about their environment. Emphasizing a broad focus on all of the potential sites for food production in the city (including the school, schoolyard and what they represent to the community), surfaces a multi-functioning methodology encompassing community identity, amenity, ecology, infrastructure and beauty envisions what could become of urban areas in the future. The primary goal is to educate future generations in the value of the food network and to give them the kind of direct hands-on experience that educators emphasize while concurrently nourishing urban communities through development of a project carried out in common, one that has health benefits for the population, that engenders a sense of long-term pride, and that empowers people to make change in their environment, even in modest or temporary ways. The idea that school design can encourage and facilitate, hinder and inhibit behaviors at school, and the architectural symbolism of schools can have a profoundly wider impact on children and their behaviors in and outside of school (Tucker). There is a significant psychological difference in learning about the environment, for the environment and in the environment (Malone). Creating public space focused on individual learning and the physical and mental health of the individual aims to balance the scales of social economic injustices. It is going to take every effort from the hyper-localized to city-wide and even regional scales to make significant urban changes to create a taxonomy of spaces to support the growth of our cities while simultaneously educating young minds on the value of understanding our ecological relationship to the city and surrounding environment.

Stormwater management basins (SWMB) are used to mitigate urban runoff. The Virginia Department of Transportation relies on dry detention basins planted with mowed turfgrass. However, these basins often retain water; resulting in cattail (Typha spp.) and tree colonization. Managing agencies request cattail eradication and trees are also removed. However, if trees were allowed to remain they could alter basin dynamics, making conditions unsuitable for cattails. In a greenhouse study we tested the impact of three shade (heavy, medium, full sun) and soil moisture (dry, moist, flooded) treatments on cattail growth. After two months, cattail biomass indicated a strong interaction between soil moisture and shade (p<.0001). Increases in shade and reductions in soil moisture resulted in decreased biomass and rhizome length. Heavy shade and dry soil produced the most reductions in cattail growth (95% less biomass, 83% smaller rhizomes than cattails in full sun and flooded soil). However, considerable growth reductions still occurred in medium shade and moist soil (66% for biomass and 74% for rhizome lengths). In a field study in four unmaintained SWMB in Virginia, environmental data (litter layer, water table, soil organic matter, etc.) and vegetation composition (cattail and other herbaceous biomass, and woody vegetation influence index) were collected from 100, 0.25-m2 plots. Principal component analysis indicated cattails and trees occupy opposing environmental spaces. Water table is most strongly correlated to cattail biomass. While these results suggest trees could eliminate cattails from SWMB, more research is needed to determine the long-term impacts of trees on basin function. / Master of Science

Urbanization is seen as a threat to biodiversity within urban ecosystems, which are largely reliant on humans for their composition. Two types of extremes exist in the spectrum of urban domestic gardens; on one end, the typical urban garden which is planted by landscapers at the time the house is built and is generally left unchanged, and, at the other, a "wild" landscape planted entirely with native plants which provides habitat for native fauna and pollinators. This study assesses the plant choices made by members of organized gardening groups-the Denton County Master Gardeners (DCMG), the Elm Fork Master Naturalists (EFMN), the Trinity Forks Native Plant Society (TFNPS), and Keep Denton Beautiful (KDB)-and toward which extreme these choices put these gardens on the psectrum. TFNPS and EFMN both fall closer to the wild garden extreme, with TFNPS the closest to a "wild garden." DCMG was almost directly between the two extremes, but fell closer to the typical urban garden. By looking at how these groups manage their gardens, we begin to understand the ways in which gardeners can mitigate and soften the harsh changes between wild landscapes and urban environments. Collaboration between groups could have the potential to encourage more people to use native plants which provide habitat for native fauna and pollinators if those in the typical urban garden spectrum could find in the "wild" gardens of those on the opposite end of the spectrum.

Nutrient inputs into the environment greatly impact urban ecosystems. Appropriate management strategies are needed to limit eutrophication of surface water bodies and contamination of groundwater. In many existing urban environments, retrofits or complete upgrades are needed for stormwater and/or wastewater infrastructure to manage nutrients. However, sustainable urban nutrient management requires comprehensive baseline data that is often not available. A Framework for Urban Nutrient (FUN) Management for Geographic Information Systems (GIS) was developed to specifically address those areas with limited data access. Using spatial analysis in GIS, it links water quality, land use, and socio-demographics, thereby reducing data collection and field-based surveying efforts. It also presents preliminary results in a visually accessible format, potentially improving how data is shared and discussed amongst diverse stakeholders. This framework was applied to two case studies, one in Orange County Florida and one in Placencia, Belize. A stormwater pond index (SPI) was developed to evaluate 961 residential wet ponds in Orange County, Florida where data was available for land use and socio-demographic parameters, but limited for water quality. The SPI consisted of three categories (recreation, aesthetics, education) with a total of 13 indicators and provided a way to score the cultural and ecosystem services of 41 ponds based on available data. Using only three indicators (presence of a fence, Dissolved Oxygen (DO) < 4 mg/l, and water depth < 3 ft), 371 out of 961 stormwater ponds were assessed. Additional criteria based on socio-demographic information (distance to a school, population density, median household income under $50,000, percentage of population below the poverty line, and distance to parks) identified seven wet ponds as optimum for potential intervention to benefit residents and urban nutrient management purposes. For the second case study, a water quality analysis and impact assessment was performed for the Placencia peninsula and lagoon in Belize. This study had access to water quality data, but limited land use data and very limited socio-demographic data. Since May 2014, water quality samples have been taken from 56 locations and analyzed monthly. For this study, Dissolved Oxygen (DO), Nitrate (NO3--N), Ammonia (NH3), Chemical Oxygen Demand (COD), and 5-Day Biochemical Oxygen Demand (BOD5), Escherichia coli (E. coli), and Enterococci were selected to assess spatial and temporal variation of water quality in the groundwater on the peninsula as well as the surface water in lagoon, estuaries and along the coast. A spline interpolation of DO, Nitrate, BOD5, and COD for June 2016 indicated the concentration distribution of those parameters and areas of special concern. A spatial analysis was conducted that showed that Nitrate and Enterococci exceeded the effluent limits of Belize very frequently in the complete study area while the other parameters contributed to the identification of key areas of concern. As a high variability of concentrations over time was observed, a temporal analysis was conducted identifying a link between the water quality data and two temporal impact factors, rainfall and tourism. The two case studies showed the broad and flexible application of the FUN management for GIS and the great advantages the use of GIS offers to reduce costs and resources use.

The ecosystem services (ES) concept is meant to facilitate consideration of the value of nature in conservation and landscape management processes by translating ecosystem functions into human benefits. Incorporating the ES concept into policy and decision-making has proven difficult due to challenges in identifying, measuring, and locating services and in predicting the impacts of decisions upon them. ES mapping offers a key solution to increase our understanding of the spatial patterns of ES supply and demand and the spatial relationships between them, but may be challenging to implement given a lack of spatial data related to ES or existence of such data at coarse resolution that may not facilitate accurate ES quantification, mapping and modeling. This issue is particularly acute in urban settings where landscapes are highly heterogeneous and fragmented. This research seeks to improve our understanding of urban ES supply, demand and the relationships between them, as well as the impacts of spatial scale, input data quality and method choice on ES mapping in urban landscapes. The dissertation is composed of three studies. In the first study, I introduce a spatially-explicit framework for quantifying and mapping ES supply and demand using carbon storage and sequestration services as an example. This framework assesses supply based on biophysical conditions and demand based on socioeconomic characteristics, allowing for more integrative ES assessments in urban areas. In the second study, I evaluate the sensitivity of ES maps to input spatial data resolution and method choice (ecosystem component-based and land-cover proxy-based methods) in a heterogeneous urban landscape using biomass carbon storage as an example. I find that ES map accuracy is highly dependent on analytical scales and input data representativeness. ES estimates based on ecosystem-component data are more accurate than those based on land-cover proxies. The accuracy of land-cover proxy-based maps, however, can be increased by using high-resolution land-cover maps. The third study aims to increase understanding of ES supply, demand, and supply-demand balance in urban contexts. To this end, I create a high-thematic-resolution land-cover dataset and combine it with the InVEST pollination model to assess the capacity of urban ecosystems to supply pollination services to satisfy the demands of urban agriculture. I find using land-cover dataset at a higher thematic resolution enhances the accuracy of pollination estimates, highlighting the importance of considering scale and land-use dependencies in urban ES mapping. Combined, these studies advance our knowledge of ES supply, demand and the relationships between them, and provide new insight into the impacts of input data spatial and thematic resolution and method choice on the accuracy of urban ES maps.

Eighty percent of the Canadian population lives in urban centres, where typical land use patterns negatively impact urban ecosystems and decrease quality of life. Current municipal Community Improvement Plans target urban vacancies for intensification efforts, which can increase fragmentation and degradation of the urban ecosystem. This project examines the urban environment: its vacancies, ecological patterns and human impacts. A strategy was derived from ecological principles aiming to design more sustainable urban landscape patterns. Applied to the Two Rivers neighbourhood in Guelph, Ontario, the strategy identified 19.5 hectares of land capable of contributing to more sustainable ecological patterns of which 12.41 hectares were brownfields. Results revealed 4.3% more high-quality land cover, in 53% more patches, 45 m closer together, but with increasing edge contrast. An area-wide strategic integration of vacant lands may provide previously unconsidered opportunities to improve urban ecological patterns and create a more sustainable urban environment.

Submitted by Vasti Diniz (vastijpa@hotmail.com) on 2017-07-27T13:27:27Z No. of bitstreams: 1 arquivototal.pdf: 23667086 bytes, checksum: d79db72c9c1827b6ed8b7e57a18419e9 (MD5) / Made available in DSpace on 2017-07-27T13:27:27Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 23667086 bytes, checksum: d79db72c9c1827b6ed8b7e57a18419e9 (MD5) Previous issue date: 2016-10-17 / Nowadays there is a need for the development and implementation of environmental monitoring techniques to present and provide reliable, practical information and easy to obtain the major spheres of government and society inserted in a particular ecosystem, especially the river ecosystems of medium-sized cities as the case of João Pessoa. One such technique is the application of Sustainability Indexes, which coalesce qualitative and quantitative aspects of social, environmental, economic and institutional aid and structure the planning of urban and environmental management of the municipality, critically evaluating the effectiveness of urban management methodology, relating the possibility of proposing adaptations urban interventions and the use of other monitoring tools such as remote sensing techniques. In this way the natural resources of a territory are a watershed or a city, become the main environmental indicators related to sustainability and can be influenced by several factors related to the biotic resources, physical and social. Relations between the biotic and abiotic means are part of a sensitive balance, which is why the changes that interfere in these relations present in the urban environment can change their quality. Thus, developing an index that best represent the environmental sustainability trend, providing warning information to society and to the government and therefore propose conservation and harmonization of actions between the urban environment and the ecosystem services provided by rivers and green areas in the João Pessoa city, as well as presenting the new designs physiographic arising from changes in the urbanization of areas close to rivers involved in the research, makes up the backbone of this work. The methodology used in this study is focused on the evaluation of the performance of the four dimensions of sustainability in rivers Cuiá, Jaguaribe, Cabelo, Aratu and Jacarapé. It concludes - that this work is revealed vulnerabilities and potentials of urban socioecossistem at odds with the plans and city development projects relative harmony with the natural environment, still present, where the high degree of urbanization without proper planning deteriorates continuously environmental conditions and reflects the greater need of government and society, work in an integrated manner in the conservation of the environment, social equity and economic development. / Na atualidade existe a necessidade do desenvolvimento e aplicação de técnicas de monitoramento ambiental, que apresentem e forneçam dados confiáveis, práticos e de fácil obtenção às principais esferas do poder público e população inserida em um determinado ecossistema, sobretudo os ecossistemas lacustres das cidades de médio porte, como é o caso de João Pessoa, Estado da Paraíba. Uma dessas técnicas é a aplicação de Índices de Sustentabilidade, que aglutinam aspectos qualitativos e quantitativos das dimensões social, ambiental, econômica e institucional que auxiliam e estruturam o planejamento e a gestão ambiental urbana de um município, avaliando criticamente a eficácia da metodologia de gerenciamento urbano, relacionando a possiblidade de propor adaptações às intervenções urbanas e o uso de outras ferramentas de monitoramento, como técnicas de sensoriamento remoto. Neste sentido, os recursos naturais de um território, quer seja uma bacia hidrográfica ou uma cidade, se tornam os principais indicadores ambientais relacionados à sustentabilidade e podem ser influenciados por diversos fatores relacionados aos meios bióticos, físicos e sociais. As relações entre os meios bióticos e abióticos fazem parte de um sensível equilíbrio, motivo pelo qual as alterações que interferem nessas relações presentes no ambiente urbano podem alterar a sua qualidade. Assim, desenvolver um índice que melhor represente a tendência de sustentabilidade ambiental, fornecendo informações de advertência à sociedade e ao poder público e consequentemente, propor ações de conservação e harmonização entre o ambiente urbano e os serviços ecossistêmicos fornecidos pelos rios e áreas verdes no município de João Pessoa, bem como apresentar os novos desenhos fisiográficos decorrentes da evolução da urbanização das áreas próximas aos rios envolvidos na pesquisa, compõe a estrutura principal deste trabalho. A metodologia utilizada neste trabalho é focada na avaliação do desempenho das quatro dimensões da sustentabilidade no entorno dos rios Cuiá, Jaguaribe, Cabelo, Aratu e Jacarapé. Conclui – se que neste trabalho são reveladas as vulnerabilidades e potencialidades de um socioecossistema urbano em descompasso com os planos e projetos de desenvolvimento das cidades em relação à harmonia com os ambientes naturais, ainda presentes, onde o elevado grau de urbanização sem o devido planejamento deteriora continuamente as condições ambientais, bem como remete a maior necessidade do poder público e da sociedade, trabalhar de maneira integrada na conservação do meio ambiente, equidade social e desenvolvimento econômico.

Les régions urbaines imposent d’intenses et multiples changements environnementaux sur les écosystèmes qu’elles contiennent et qui les entourent, et les réponses des écosystèmes à ces environnements urbains est encore relativement peu connue, même pour des processus fondamentaux comme les cycles du carbone (C) et de l’azote (N). Ce travail utilise une chronoséquence de systèmes sol-arbre d’alignement (plantations de Tilia tomentosa Moench) de 75 ans, situés à Paris, comme étude de cas principale, afin de détecter des tendances de long terme dans les cycles urbain du C et du N et d’en inférer les potentiels mécanismes sous-jacents. Un patron d’accumulation du C et du N dans les sols de rue est décrit, et nous faisons l’hypothèse que le C dérivé des racines, et le N issu des dépôts atmosphérique et apports animaux, s’accumulent dans ces sols. Ensuite, une analyse des fractions organo-minérales des sols suggère qu’il y a bien une accumulation de matière organique du sol (MOS) relativement récente. Les analyses 13C et 15N suggèrent que les racines sont un contributeur majeur à cette augmentation de la teneur en MOS et de la rétention du N exogène. Les taux de nitrification et de dénitrification potentielles augmentent avec l’âge des systèmes de rue, ce qui semble être déterminé par une augmentation des bactéries oxydant l’ammoniaque. Les dynamiques de long terme pour le C semblent caractérisées by une augmentation des apport hypogés couplée à des mécanismes de stabilisation du C racinaire. Pour le N, les sorties de N semblent contrebalancées par d’importants apports exogènes et les racines, apports dont une partie est retenue dans la biomasse végétale (racines) et la MOS. / Urban areas impose multiple and intense environmental changes on the ecosystems they contain or that surround them, and the ecosystem responses to urban environments are still poorly known, even on fundamental ecosystem processes such as carbon (C) and nitrogen (N) cycling. The dynamics of urban ecosystems, especially on the long-term, have received little attention. The present work uses a 75-year chronosequence of street soil-tree systems (plantations of Tilia tomentosa Moench) in Paris, France, as its main case study to detect long-term patterns in urban C and N cycling and infer potential underlying mechanisms. This thesis describes age-related patterns of C and N accumulation in soils, and we hypothesize that tree root-derived C and deposited N from the atmosphere and animal waste accumulate in soils. Then, an analysis of soil particle-size fractions further points towards a recent accumulation of soil organic matter (SOM), and 13C and 15N analysis suggests that tree roots are a major contributor to the increase of SOM content and N retention. Potential nitrification and denitrification rates increase with street system age, which seems driven by an increase in ammonia-oxidising bacteria. The long-term dynamics of C seem characterized by increasing belowground inputs coupled with root-C stabilization mechanisms. For N, the losses are likely compensated by exogenous inputs, part of which is retained in plant biomass (roots) and SOM.These results are then discussed in light of results obtained on Parisian black locust systems (Robinia pseudoacacia Linnæus), as well as other data, and management recommendations are proposed.