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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Investigating the Potential of Land Use Modifications to Mitigate the Respiratory Health Impacts of NO2: A Case Study in the Portland-Vancouver Metropolitan Area

Rao, Meenakshi 02 June 2016 (has links)
The health impacts of urban air pollution are a growing concern in our rapidly urbanizing world. Urban air pollutants show high intra-urban spatial variability linked to urban land use and land cover (LULC). This correlation of air pollutants with LULC is widely recognized; LULC data is an integral input into a wide range of models, especially land use regression models developed by epidemiologists to study the impact of air pollution on human health. Given the demonstrated links between LULC and urban air pollution, and between urban air pollution and health, an interesting question arises: what is the potential of LULC modifications to mitigate the health impacts of urban air pollution? In this dissertation we assess the potential of LULC modifications to mitigate the health impacts of NO2, a respiratory irritant and strong marker for combustion-related air pollution, in the Portland-Vancouver metropolitan area in northwestern USA. We begin by measuring summer and winter NO2 in the area using a spatially dense network of passive NO2 samplers. We next develop an annual average model for NO2 based on the observational data, using random forest -- for the first time in the realm of urban air pollution -- to disentangle the effects of highly correlated LULC variables on ambient NO2 concentrations. We apply this random forest (LURF) model to a 200m spatial grid covering the study area, and use this 200m LURF model to quantify the effect of different urban land use categories on ambient concentrations of NO2. Using the changes in ambient NO2 concentrations resulting from land use modifications as input to BenMAP (a health benefits assessment tool form the US EPA), we assess the NO2-related health impact associated with each land use category and its modifications. We demonstrate how the LURF model can be used to assess the respiratory health benefits of competing land use modifications, including city-wide and local-scale mitigation strategies based on modifying tree canopy and vehicle miles traveled (VMT). Planting trees is a common land cover modification strategy undertaken by cities to reduce air pollution. Statistical models such as LUR and LURF demonstrate a correlation between tree cover and reduced air pollution, but they cannot demonstrate causation. Hence, we run the atmospheric chemistry and transport model CMAQ to examine to what extent the dry deposition mechanism can explain the reduction of NO2 which statistical models associate with tree canopy. Results from our research indicate that even though the Portland-Vancouver area is in compliance with the US EPA NO2 standards, ambient concentrations of NO2 still create an annual health burden of at least $40 million USD. Our model suggests that NO2 associated with high intensity development and VMT may be creating an annual health burden of $7 million and $3.3 million USD respectively. Existing tree canopy, on the other hand, is associated with an annual health benefit of $1.4 million USD. LULC modifications can mitigate some fraction of this health burden. A 2% increase in tree canopy across the study area may reduce incidence rates of asthma exacerbation by as much as 7%. We also find that increasing tree canopy is a more effective strategy than reducing VMT in terms of mitigating the health burden of NO2. CMAQ indicates that the amount of NO2 removed by dry deposition is an order of magnitude smaller than that predicted by our statistical model. About one-third of the difference can be explained by the lower NO2 values predicted by CMAQ, and one-third may be attributable to parameterization of stomatal uptake.
122

Qualidade do espaço verde urbano: uma proposta de índice de avaliação. / Quality of urban green space: a proposal of evaluation index.

Alvarez, Ivan André 12 April 2004 (has links)
O objetivo deste trabalho foi propor, entre os índices já existentes, um índice que avalie a qualidade da cobertura vegetal em relação à sua função ecológica, no meio urbano. Para a composição deste índice, compararam-se os métodos de amostragem aleatória simples e de amostragem estratificada de inventários da arborização de calçadas com o censo, com a finalidade de se escolher o melhor método de levantamento quali-quantitativo para árvores de calçada. Determinou-se o número de árvores por quilômetro, número total de árvores, Índice de Diversidade de Shannon (IDS) para árvores de calçada. Foram calculados o Índice de Espaços Livres de Uso Público (IELUP), a Porcentagem de Espaços Livres de Uso Público (PELUP), o Índice de Cobertura Vegetal em Áreas Urbanas (ICVAU) e o Índice de Verde por Habitante (IVH). Foram utilizadas planta baixa digital, fotografia aérea e videografia para mensurar as áreas ocupadas pela vegetação. A unidade de paisagem escolhida para estudo foi o bairro Santa Cecília em Piracicaba, Estado de São Paulo, Brasil, nos anos de 2000 a 2003. O levantamento amostral qualitativo das árvores de calçada foi feito por amostragem aleatória simples, escolhido, no trabalho, como o melhor método para inventariar árvores de rua. Considerando o ano de 2003, para a proposição do índice, os resultados obtidos foram: a) o IELUP variou de 11,42 a 41,62m2/hab (videografia); b) o PELUP variou de 1,52% a 2,89%; c) o ICVAU foi de 25,76m2 (forração + cobertura arbórea) e de 16,48 m2 (cobertura arbórea); d) o IVH foi de 101,96m2/hab (forração + cobertura arbórea) e de 65,21m2/hab (cobertura arbórea). Para a avaliação de espaços verdes urbanos foi feita discussão em função de obter-se um chamado "Índice de Qualidade do Espaço Verde Urbano" (IQEVU), particularizado para a função ecológica, então denominado "Índice de Qualidade do Espaço Verde Urbano com Função Ecológica" (IQEVUe). Os parâmetros para avaliação deste último índice foram: sombreamento, para árvores de calçadas; hidrologia, fixação de Carbono e influência de temperatura, para todos os espaços verdes. O IQEVUe mostrou-se adequado e coerente para mensurar os benefícios da vegetação em áreas urbanas, fornecendo subsídios para o planejamento e o manejo de cidades. / The aim of this work was to propose a new index, amongst other already known, that evaluates the quality of green coverage in relation to its ecological role in urban environment. To elaborate this index, simple random and stratified random sampling were compared with the census, in order to assess the best qualitative and quantitative method to do the tree inventory. A survey of sidewalk arborisation, as well as trees per kilometre, total number of trees and the Shannon Diversity Index (IDS) of sidewalk trees were evaluated. Amongst the studied indexes were the Index of Open Spaces for Public Use (IELUP), Percentage of Open Spaces for Public Use (PELUP), Index of Green Coverage for Urban Areas (ICVAU) and Index of Green per Inhabitant (IVH), by means of digital plan, aerial photography and videography for the areas covered by vegetation measurement. Santa Cecilia District in Piracicaba City, Sao Paulo State, Brazil, was the object of study from 2000 to 2003. The qualitative sampling survey of trees was carried out by simple random sampling, as found to be the most adequate to survey sidewalk trees. Data obtained for 2003, the year chosen to propose the new index, were: a) IELUP varied from 11.42 to 41.62m2/inhab, using videography; b) PELUP varied from 1.52% to 2.89%; c) ICVAU was 25.76m2 (coverage + tree canopy) and 16.48m2 ( tree canopy ); d) IVH consisted of 101.96m2/hab (coverage + tree canopy) and 65.21m2/inhab (tree canopy). The index for the evaluation of green spaces, so named "Index for Quality of Green Urban Space" (IQEVU) was one of the subsidies to study and propose the "Index for Quality of Green Urban Space with Ecological Role" (IQEVUe). The parameters for evaluation of such index were the shading from sidewalk trees; hydrology, Carbon sequestration and temperature influence for all green space. In this study, the proposed IQEVUe seems to be adequate and coherent as an evaluation method for the benefits of urban vegetation, providing subsidies for the planning and management of cities.
123

Fruitful Communities: Evaluating the History and Impacts of TreePeople’s Fruit Tree Program

Imhoff, Kayla B 01 April 2013 (has links)
TreePeople is a Los Angeles based non-profit organization that uses environmental education, initiatives, and programs to engage with the greater community to work towards the goal of a sustainable future for Los Angeles. The Fruit Tree Program is one of TreePeople’s longest running programs of 29 years, which distributes free bare-root fruit trees to economically disadvantaged communities as a source of fresh fruit and the other environmental benefits that trees offer. This paper is a comprehensive report detailing the history of the program and the impacts it has had on communities across Los Angeles County. Looking at three communities in Los Angeles and interviewing key community members from these communities, I identified the impacts that the program has had on addressing important urban environmental concerns and facilitating community development.
124

Integrationsprojekte als Aufgabe urbaner Forstwirtschaft / Integrative Projects as a Task of Urban Forestry

Vering, Katharina 17 September 2007 (has links)
No description available.
125

Qualidade do espaço verde urbano: uma proposta de índice de avaliação. / Quality of urban green space: a proposal of evaluation index.

Ivan André Alvarez 12 April 2004 (has links)
O objetivo deste trabalho foi propor, entre os índices já existentes, um índice que avalie a qualidade da cobertura vegetal em relação à sua função ecológica, no meio urbano. Para a composição deste índice, compararam-se os métodos de amostragem aleatória simples e de amostragem estratificada de inventários da arborização de calçadas com o censo, com a finalidade de se escolher o melhor método de levantamento quali-quantitativo para árvores de calçada. Determinou-se o número de árvores por quilômetro, número total de árvores, Índice de Diversidade de Shannon (IDS) para árvores de calçada. Foram calculados o Índice de Espaços Livres de Uso Público (IELUP), a Porcentagem de Espaços Livres de Uso Público (PELUP), o Índice de Cobertura Vegetal em Áreas Urbanas (ICVAU) e o Índice de Verde por Habitante (IVH). Foram utilizadas planta baixa digital, fotografia aérea e videografia para mensurar as áreas ocupadas pela vegetação. A unidade de paisagem escolhida para estudo foi o bairro Santa Cecília em Piracicaba, Estado de São Paulo, Brasil, nos anos de 2000 a 2003. O levantamento amostral qualitativo das árvores de calçada foi feito por amostragem aleatória simples, escolhido, no trabalho, como o melhor método para inventariar árvores de rua. Considerando o ano de 2003, para a proposição do índice, os resultados obtidos foram: a) o IELUP variou de 11,42 a 41,62m2/hab (videografia); b) o PELUP variou de 1,52% a 2,89%; c) o ICVAU foi de 25,76m2 (forração + cobertura arbórea) e de 16,48 m2 (cobertura arbórea); d) o IVH foi de 101,96m2/hab (forração + cobertura arbórea) e de 65,21m2/hab (cobertura arbórea). Para a avaliação de espaços verdes urbanos foi feita discussão em função de obter-se um chamado “Índice de Qualidade do Espaço Verde Urbano” (IQEVU), particularizado para a função ecológica, então denominado “Índice de Qualidade do Espaço Verde Urbano com Função Ecológica” (IQEVUe). Os parâmetros para avaliação deste último índice foram: sombreamento, para árvores de calçadas; hidrologia, fixação de Carbono e influência de temperatura, para todos os espaços verdes. O IQEVUe mostrou-se adequado e coerente para mensurar os benefícios da vegetação em áreas urbanas, fornecendo subsídios para o planejamento e o manejo de cidades. / The aim of this work was to propose a new index, amongst other already known, that evaluates the quality of green coverage in relation to its ecological role in urban environment. To elaborate this index, simple random and stratified random sampling were compared with the census, in order to assess the best qualitative and quantitative method to do the tree inventory. A survey of sidewalk arborisation, as well as trees per kilometre, total number of trees and the Shannon Diversity Index (IDS) of sidewalk trees were evaluated. Amongst the studied indexes were the Index of Open Spaces for Public Use (IELUP), Percentage of Open Spaces for Public Use (PELUP), Index of Green Coverage for Urban Areas (ICVAU) and Index of Green per Inhabitant (IVH), by means of digital plan, aerial photography and videography for the areas covered by vegetation measurement. Santa Cecilia District in Piracicaba City, Sao Paulo State, Brazil, was the object of study from 2000 to 2003. The qualitative sampling survey of trees was carried out by simple random sampling, as found to be the most adequate to survey sidewalk trees. Data obtained for 2003, the year chosen to propose the new index, were: a) IELUP varied from 11.42 to 41.62m2/inhab, using videography; b) PELUP varied from 1.52% to 2.89%; c) ICVAU was 25.76m2 (coverage + tree canopy) and 16.48m2 ( tree canopy ); d) IVH consisted of 101.96m2/hab (coverage + tree canopy) and 65.21m2/inhab (tree canopy). The index for the evaluation of green spaces, so named “Index for Quality of Green Urban Space” (IQEVU) was one of the subsidies to study and propose the “Index for Quality of Green Urban Space with Ecological Role” (IQEVUe). The parameters for evaluation of such index were the shading from sidewalk trees; hydrology, Carbon sequestration and temperature influence for all green space. In this study, the proposed IQEVUe seems to be adequate and coherent as an evaluation method for the benefits of urban vegetation, providing subsidies for the planning and management of cities.
126

The contribution of trees to local livelihoods in urban areas

Kaoma, Humphrey January 2013 (has links)
Trees in natural forests are widely known for their essential contribution to rural livelihoods in developing countries, providing both consumptive and non-consumptive products to rural inhabitants. These benefits are also obtained from trees in urban forests and used by urban households. In the past decades, the role of urban trees to urban livelihoods, municipalities, local and global environment has often been overlooked by researchers and development agencies, and hence are poorly documented, especially in Africa. In South Africa, the increase in urbanisation and urban poverty means many urban residents are expected to be dependent on trees and tree products from homesteads, neighbourhoods and edges of towns. There is however a paucity of literature on the potential of trees in sustaining livelihoods and poverty alleviation in urban areas. This study determined the magnitude and nature of the direct contribution of trees and tree products to local livelihoods in different urban residential areas (informal, Reconstruction and Development Programme (RDP), and township) in three South African towns (Tzaneen, Bela Bela and Zeerust) which cover a rainfall gradient from relatively higher (775 mm p.a.) to low (575 mm p.a.). The results showed that most (90%) households had an interest in planting and managing trees on homesteads, given the high proportion (71%) of residents who had planted trees on their homesteads. The abundance of trees followed the moisture gradient, with Tzaneen having a larger share (46.4%) of trees, followed by Bela Bela (27.5%) and Zeerust (26.1%). Larger plots in the informal residential area accounted for the larger proportion (42.8%) of trees on homesteads, followed by the township (32.9%) and RDP households being the least because they were recently established. Tree density was also higher in the high rainfall town but the pattern did not follow the moisture gradient between Bela Bela and Zeerust due to little rainfall difference. However, tree density across residential areas was similar to the proportion of trees on homesteads in residential areas. The most common tree species were alien, and mainly exotic fruit trees made up two-thirds of the trees encountered. Most households collected various products from urban trees, particularly fuelwood, from edges of towns. This was especially by households with lower cash income. However, fruits were collected from homesteads regardless of the wealth status. Tree products had a significant contribution to the total annual household income, with fuelwood alone contributing up to R5 663 per household per annum, equivalent to two-three month household cash income. Tree products added 20% to total household income, which represents the amount of money households save by collecting tree products for free. Therefore, trees within and around urban areas contribute significantly to livelihoods and reduce poverty in urban areas. There is need therefore to encourage urban residents to plant trees on homesteads and policy makers to come up with policies that promote sustainable harvesting of tree products from areas surrounding urban areas.
127

Investigating the potential for Jacaranda street trees to mitigate climate change in Tshwane, South Africa

Mangena, Kensani Charlene 02 1900 (has links)
Bibliography: leaves 135-145 / Climate Change poses a great risk to our future as species on Earth. The impacts thereof will have far reaching consequences on every aspect of our daily lives and ultimately on our ability to survive and thrive as humans. It is therefore important, particularly in urban areas where most of the human population live, for the investment of resources and expertise into mitigating these impacts and ensuring the resilience of urban areas. The urban forest provides climate change mitigation benefits for urban areas through carbon sequestration. In order to encourage investment and protection of the urban forest, this benefit must be quantified and afforded a monetary value. This study calculated the amount of carbon dioxide sequestrated by the Jacaranda mimosifolia street tree in the City of Tshwane and afforded this amount a monetary value in both South African Rands and American Dollars through the South African Carbon Tax Bill. This study followed the baseline study by Stoffberg (2006) looking at how much carbon dioxide had been sequestrated by the Jacaranda trees over the past 15 years post the baseline study and what monetary value do the trees now have through legislation that was not available during the baseline study. The study also observed the variables that may have affected the amount of carbon dioxide sequestrated by the trees. Although some areas saw a drop in the Total Carbon Dioxide Equivalent sequestrated since 2004, the total amount for the whole city remained stable. Through the Carbon Tax Bill, the value of these trees has increased significantly encouraging the municipality to invest in the maintenance and protection of the Jacaranda street trees in the City of Tshwane in order to preserve their carbon sequestration benefits / Environmental Sciences / M. Sc. (Environmental management)
128

Tree Growth and Spatial Pattern in Two Forest Park Permanent Plots: A Look at Stand Composition and Condition

McDonald, Hannah Beth 01 January 2011 (has links)
In June of 2010, two permanent research plots were established in Forest Park, based on their differing proximities to downtown Portland, Oregon. As part of a long-term ecological research project that seeks to explore the ecological status and human thumbprint on this 5,100 acre forested reserve, the 2010 tree data was investigated for emergent compositional and spatial patterns. Stand composition, tree size, growth rates, and spatial patterns were analyzed, along with ecological and land use histories. Results indicate that the Balch plot, more closely located to the urban center, has different stand composition, condition, and vegetation growth rates, compared to the more rural Miller site. This study supports findings from a study done by Broshot in 2009, where more urban plots demonstrate a different stand composition and recruitment pattern than rural sites. The study is an initial step for exploring questions regarding the ecological status of Forest Park and how land use and disturbance, past and present, shape Portland's forested reserve.
129

A map system to disseminate national science on forests for the creation of regional tree planting prioritization plans

Whalen, Kevin Christopher 07 December 2017 (has links)
No description available.
130

Governance and management of urban trees and green spaces in South Africa: ensuring benefits to local people and the environment

Chishaleshale, Mwale January 2013 (has links)
In the face of rapid urbanization and global climate change, urban trees and green spaces (UTGS) can contribute to the welfare of people and the urban environment. Urban trees and green spaces can assist to address urbanization challenges related to environmental degradation. While functions of UTGS have been well documented in the developed world, they have not yet received full attention in much of sub-Saharan Africa. Consequently, UTGS are under threat from urban development and fragmentation. Notably, the problems associated with UTGS also fall into the governance realm and indications are that poor governance and management of UTGS can negatively influence the potential benefits of UTGS to local people and the environment. This formed a basis for this research. The main objective of the study was to determine the current governance and management approaches to UTGS in South Africa. Through document search and review, the study determined the governance institutions influencing UTGS at national level and at provincial level (in the Limpopo and Eastern Cape Provinces). Face-to-face and online survey methods were used to determine the extent to which 28 local municipalities had adopted planned, systematic and integrated management of UTGS. The snowball approach was used to determine the key actors involved in UTGS activities and interviews were conducted to establish the roles and capabilities of these actors. A total of 540 household interviews were conducted to determine the institutional factors influencing local peoples’ ability to access, plant and use UTGS. The findings of the study showed that UTGS have not been adequately covered in existing governance institutions and practice at national and provincial levels. Local government municipalities were not managing their UTGS in a planned or systematic manner due to constraining factors such as insufficient funds, insufficient personnel, lack of equipment and lack of political support. Only 7.1 % of the surveyed municipalities had an urban tree management plan and an estimate of the urban tree stock; 32.1 % had tree policies; 28.6 % had tree bylaws; 21.4 % had tree planting schedules; 10.7 % had tree maintenance schedules and only 3.6 % had tree inspection schedules. Key actors involved in UTGS activities differed among levels of government. The actors included national and provincial government departments, local government municipalities, Non-Governmental Organizations, private sector companies and local volunteers. Most of the actors, however, either planted trees or provided tree seedlings to municipalities and the local people. Tenure security was a key institutional factor affecting peoples’ ability to plant, use or even remove trees from their residential plots. The same applied to trees in the streets and public parks. Whereas most respondents did not require permission to plant (79.8 %) or remove (75 %) trees on their residential plots, a majority of them required permission to plant and remove trees from streets (over 70 %) and public parks (over 80 %). However, with regard to planting and removing urban trees in public open spaces, 54% of the respondents indicated that permission was not required suggesting a lack of clarity among local residents on the issue. Overall, the findings of this study indicate that there is no political recognition and support for UTGS at almost all levels of government. This has resulted in the lack of incorporation of UTGS in urban planning and development and has caused UTGS to receive limited funding to permit planned and systematic management. Given the current rates of urbanization and urban development, the lowly prioritised UTGS are vulnerable to exploitation. To conserve UTGS and promote their potential contribution to local people and the environment, UTGS must be recognized and placed on political and development agendas. There is a need to develop national guidelines for UTGS management, assess the extent of the urban forest resource in local municipalities, clearly define the roles and capabilities of different actors, integrate UTGS in the urban planning and development system, and most of all seek to involve the local people in overall management and governance of UTGS.

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