Abstract
The urban forest is an important natural capital asset providing essential ecological, social, and economic benefits to people living in cities. Research contained within this dissertation examines urban forest structure and management through the lens of strong sustainability and has as its central focus the question of where to prioritize planting of trees in a densely populated, and continually expanding, North American urban centre. Three independent research studies are included, each of which addresses a dimension of the urban forest that falls within one of the three subsystems of sustainability. The first study focuses on urban forest ecological service delivery with a specific focus on the relationship between forest canopy closure and summer surface temperatures across the City of Toronto, Canada. The second study examines a social dimension of the urban forest—identifying distributional inequalities in city resident access to urban tree canopy as a function of their household income. In the third study, an economic dimension of urban sustainability is investigated by examining the legacy of street tree planting decisions and their relationship to ash tree mortality caused by the emerald ash borer (Agrilus planipennis). In addition to adding to scholarship concerning the processes and relationships examined within each sustainability subsystem, common themes arising across each of the studies are identified and discussed. These individual research studies and intersecting themes serve as the basis for an innovative approach to prioritizing urban tree planting that seeks to integrate a sustainability subsystems approach to the decision-making process.
Highlights
1.1 RESEARCH CONTEXTSUSTAINABILITY AND ENVIRONMENTAL DECISION MAKINGIn many ways, this dissertation falls under the theme of sustainability and how sustainability principles have a role in the environmental decision-making process
2.4.1 Land-cover classification accuracy The MLC of the Landsat Thematic Mapper 5 (TM5) imagery achieved an overall accuracy of 81.5% (Table 2-1), a result consistent with other land-cover classification accuracies reported in the literature (e.g. Lu & Weng, 2006; Prol-Ledesma et al, 2002)
This research presents a novel method of considering the spatial distributional inequalities of the urban forest and provides a methodological framework for use by researchers focusing on environmental justice studies in North American cities
Summary
1.1 RESEARCH CONTEXTSUSTAINABILITY AND ENVIRONMENTAL DECISION MAKINGIn many ways, this dissertation falls under the theme of sustainability and how sustainability principles have a role in the environmental decision-making (or EDM) process. As one category of tree cover within the broader urban forest, street trees typically constitute a smaller proportion of the total tree biomass when compared with other categories of urban forest such as park, institutional, or private residential trees (Maco & McPherson, 2002) Despite their exposure to more challenging growing conditions (Bassuk & Whitlow, 1988) often resulting in retarded growth rates (Grabosky & Gilman, 2004; Quigley, 2004) and increased mortality of younger trees (Koeser et al, 2013; Lu et al, 2010; Nowak et al 2004;), several detailed analyses of public trees (or municipal forests) have confirmed that street trees provide greater financial benefits to city dwellers than the costs associated with their planting and maintenance (McPherson et al, 1997; McPherson et al, 2005; McPherson & Simpson, 2002). The authors suggest, that this increased investment is reflective of efforts to decrease mortality and increase the longevity of an urban forest with a very young age distribution and that the benefit to cost ratio will increase appreciably over time as tree maintenance and removal costs decrease and the benefits delivered by maturing trees increase rapidly (McPherson et al, 2005)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have