In Vancouver, British Columbia, Canada, issues once thought isolated to large metropolitan areas such as Los Angeles, Tokyo, and Mexico City—increased storm water runoff, the urban heat island effect, deterioration of air and water quality, and loss of habitat and biodiversity—now threaten a region once described as "lotus-land" (Wynn and Oke, 1992, xi). European research supports the ability of green roofs to mitigate many of these ill effects of urbanization. The investigation undertaken by this thesis explores the role green roofs might play in the Greater Vancouver's transition to sustainable design and development. The thesis limits the scope of its investigation to inaccessible, extensive systems, alternately known as eco-roofs, which are relatively lightweight and low-maintenance. The paper reviews the historical and contemporary development of eco-roofs, including past and present motivations for their use and the evolution of construction methods. It then summarizes the potential impacts—aesthetic improvements, increased biodiversity, protection of the roof membrane, meso and microclimate mitigation, improved building insulation, and stormwater management—currently attributed to green roof implementation. The remainder of the thesis evaluates which of these potential impacts apply to Vancouver, in light of the city's physical contextual setting, and the ambient influences of the Greater Regional District The reported benefits of green roofs are numerous, and incremental contributions to improving environmental conditions should not be discounted or trivialized, however, in Vancouver and its region, eco-roofs' greatest impact, and consequently financial feasibility, resides in the mitigation of stormwater volumes. Eco-roofs' detain rainfall and slow runoff from the roof during and immediately following a storm event. This reduces peak flows, and corresponding CSO and flooding problems, and encourages a more natural hydrology by increasing the chances for stormwater infiltration. Storm runoff, and issues related to it, constitutes a persistent and growing problem in the GVRD. The ability of an eco-roofs even thin profile to mitigate this pressing issue could result in widespread, and even unforeseen, positive ramifications. / Applied Science, Faculty of / Architecture and Landscape Architecture (SALA), School of / Graduate

Large cities around the world are faced with severe challenges that make life difficult for the growing population. These problems include air pollution, flooding, urban heat island effect and windstorms. Now there is a strong emphasis on resilience. Urban forestry, generally defined as the management of trees in cities for human well-being, has been suggested as a strategy that can help cities manage these problems. However, urban forestry especially in developing countries faces several problems and research gaps that must be addressed before the benefits can be realized. Across Ghana, a crisis of urban forest decline prevails. Increasingly, problems in urban forestry are related to land access and exclusion, unclear institutional framework for governance and challenges related to low public support and participation in decision making processes and the use of urban forests resources. It was against these backgrounds that the study was conducted. The specific objectives were to: (1) assess public perceptions and attitudes toward urban forestry, (2) analyse the institutional framework for urban forest governance and (3) explore how access to land affects urban forestry development. These are crucial but little studied issues in Ghana to date. Drawing on a case study approach with mixed methods in the city of Kumasi, Ghana, the overall goal of the dissertation was to contribute to policy recommendations for improving urban forestry in the study area as well as to contribute to scientific literature on access and institutions. Data for the study were collected over a period of six months using both quantitative and qualitative data collection methods and techniques. Sources of secondary data included journal articles, monographs, archival records, Ghanaian newspaper publications as well as published and unpublished official reports of government organizations in Ghana. Primary data sources included a survey of 396 randomly selected urban residents from three different residential classes in Kumasi using questionnaires and Likert scales. It also involved interviews with 57 experts and key informants who were selected on the basis of their level of knowledge and involvement on the subject matter. Specifically, for objective one, that public perception and attitude toward urban forestry were being assessed, the study used stratified random sampling technique to interview as many as 132 respondents per each residential class in Kumasi. For objectives two and three, institutional and access analysis involved interviews with experts using purposive sampling technique. Data collected in the study was analysed using content analysis, descriptive statistics and two types of statistical tests; (a) 'the Pearson’s Chi-square Test of independence (χ2) and (b) Kruskal Wallis H test' of differences between responses of respondents. For objective one, the results showed that citizens in Kumasi genuinely care about urban forest and trees and found them important but were not satisfied with the current state of management. The respondents found issues related to lack of safety in public parks and gardens, destruction of utility lines and buildings by urban trees among the most pressing problems associated with urban forestry in Kumasi. There were more similarities in opinion than differences between respondents in terms of perception. Moreover, socioeconomic and demographic factors explained perceptions only to some extent. Many respondents were willing to pay money for urban forestry development. The results revealed that the age of respondents, education and income were not significant factors affecting people’s perception and attitude towards urban forestry in the study area. For objective two, the study found out that institutions in terms of rules and regulations affect urban forestry outcomes. In spite of the benefits derived from urban forestry, Ghana's urban forestry management efforts are being undermined by institutional challenges such as lack of tenure security for parks and gardens, overconcentration of land property rights to chiefs and traditional authorities, overreliance on common fund for urban forestry development and ineffective decentralization system in Ghana. For urban forestry institutions to succeed, six action situations including financing, planning, policy and strategic direction, conflict resolution as well as monitoring needed to be considered. For objective three, the results from access analysis showed that legal means (right based way) constitute only one set of mechanisms amongst many other factors by which access to land affects urban forestry development. Other means such as violent evictions and theft (rights-denied mechanisms of access) also characterized how access to land affects urban forestry development in the case study area. Against these backgrounds, policy makers in Ghana should consider a mix of recommendations to help improve urban forestry in the study area. These include access regulations and creation of land banks for urban forestry development; security of tenure and simplification of land allocation procedures for establishing parks and gardens; adequate financing and budgeting for urban forestry development; institutionalization of urban forestry activities in spatial and development plans; active public and private sector engagement as well as selection of tree species that will provide continuous ecosystem services such as shade provision and reduction of temperature in the city. In addition, the institutional arrangement for urban forestry in Ghana is not well structured and needs a proper restructuring.

In 2006, the U.S. Forest Service implemented performance measures to evaluate urban forestry management in communities in each state. The Forest Service implemented these measures under its Community Accomplishment Reporting System (CARS). To achieve four CARS measures that pertain to management, communities must have a management plan, professional staff, tree ordinances, and an advisory or advocacy organization. It is unclear whether attaining the CARS measures reflects the status of the urban forest itself. We analyzed street tree inventories from communities in Massachusetts that met the CARS measures. We considered the net gain or loss in the number of street trees in 2007 and cost-benefit analyses from the Street Tree Resource Analysis Tool for Urban Forest Managers (STRATUM). We analyzed the diversity of street tree populations. We used a correlation analysis to discover associations between these variables and both community demographic measures and qualification of the urban forester managers. Thirty-three communities met the CARS measures and 9 had active street tree inventories. Fewer than half of the communities planted more trees than they removed in 2007. Planting and removal activity increased with tree budget. Cost-benefit analysis showed that for 8 of 9 communities with inventories, benefits of street trees outweighed the cost of management. Community population was associated with trees planted, trees removed, and tree budget. Demographic measures were not associated with tree performance. Tree warden certification did not impact tree condition or diversity, however non-certified tree wardens planted trees at a higher rate than non-certified tree wardens. Tree budgets were higher for communities with certified arborists and for communities with inventories used for management. Results serve as a baseline for future study of the impact of the CARS measures on street tree populations in Massachusetts.

Indiana University-Purdue University Indianapolis (IUPUI) / Despite growing recognition as a significant natural resource, methods for accurately estimating urban tree canopy cover extent and change over time are not well-established. This study evaluates new methods and data sources for mapping urban tree canopy cover, assessing the potential for increased accuracy by integrating high-resolution satellite imagery and 3D imagery derived from LIDAR and stereoscopic sensors. The results of urban tree canopy classifications derived from imagery, 3D data, and vegetation index data are compared across multiple urban land use types in the City of Indianapolis, Indiana. Results indicate that incorporation of 3D data and vegetation index data with high resolution satellite imagery does not significantly improve overall classification accuracy. Overall classification accuracies range from 88.34% to 89.66%, with resulting overall Kappa statistics ranging from 75.08% to 78.03%, respectively. Statistically significant differences in accuracy occurred only when high resolution satellite imagery was not included in the classification treatment and only the vegetation index data or 3D data were evaluated. Overall classification accuracy for these treatment methods were 78.33% for both treatments, with resulting overall Kappa statistics of 51.36% and 52.59%.

<p dir="ltr">The distribution of people and infrastructure in North American cities is not random, nor is it equitable. Minoritized communities often have less access to trees and forests and to the benefits that they provide. This pattern has developed over centuries. North American cities were built on indigenous land, and the location of rivers, wetlands, forests, and prairies influenced where houses were built, factories erected, parks sited, and where natural areas were preserved. As people moved to cities, wealthier individuals could afford to buy homes in places that they found more desirable. These places often were near parks or lakes and often had more trees. Less wealthy people could only afford homes in places that had less green infrastructure and places that were nearer to environmental harms like polluting industries. Unfortunately, in the United States, wealth is associated with race, meaning that from an early time its cities were segregated. As cities expanded and migration from the Jim Crow South and immigration from Eastern Europe increased, these wealthier, whiter communities restricted non-white people from moving into them with racist covenants and through redlining, deepening segregation. In this dissertation, I explored how this ecological and social history affected the ecology of a metropolitan region’s forests, and how that related to who gets to experience them. I also showed how the associations between socio-demographic variables and tree canopy varied across an urban to exurban region. Finally, I identified barriers to requesting and planting trees that residents experience and strategies that may help governments and strategies that may help overcome them. I found that communities of color had less access to forests that have a higher capacity to provide ecosystem services; that while segregation existed in urban, suburban, and exurban communities, canopy inequity did not; and that managing existing trees and working with neighborhood associations is the best way to encourage planting and stewardship of trees that can reduce tree equity.</p><p><br></p>

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