Dominik Roeser

This research investigates the role of tree planting configurations at the neighbourhood level toachieve maximum canopy cover and maximize synergies. The growth of urban forests in themost climate vulnerable sites can be part of mitigation and adaptation strategies that promotecollaboration between trans-departmental goals to combat increasing summer heat and otherthreats. Unfortunately, the areas which would benefit the most from having lush, healthy andextensive urban forests within a city are usually the ones that provide the least suitable places fortrees to establish and mature, especially in densifying urban areas. Common limitations tomaximize canopy cover in public land (i.e., where cities have ownership and managementresponsibilities of trees) include competition for space with existing infrastructure and minimalprotection for existing tree canopy and its maintenance. Therefore, this research uses GISmodelling to test multiple tree arrangement scenarios on public streets of a low-canopy coverneighbourhood in Vancouver, Canada with the purpose of achieving a goal relevant to its sizewithin the city-wide target of 30% canopy cover. Tree canopy is one among other metrics thatserve as a proxy to identify the quantity and quality of the urban forest. This investigation foundthat a low-canopy cover neighbourhood has the capacity to improve the contribution of streettrees to its total canopy cover as well as increase the canopy cover per street-segment, havingimplications in both thermal comfort and climate resilience.

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Slash-pile burning (SPB) of harvest residues continues to be a forestry management practice to reduce fuel loading and create space for planting. However, in British Columbia (BC), Canada, current estimates suggest the practice has contributed average annual greenhouse gas emissions of roughly 5 Mt CO₂e per year between 2002-2021. Furthermore, the practice prevents fiber from entering the bioeconomy, and produces substantial air pollution. This thesis aimed to answer the question: How can emissions from slash-pile burning be reduced in BC? This question was addressed using three distinct methodologies: (1) survey of BC forest professionals, (2) timber harvest modelling study evaluating the volume and location of residues generated during full-tree, clearcut harvesting in BC, and (3) an investigation of alternative practices which could feasibly replace SPB. The survey and investigation of alternatives helped to outline the current challenges of residue management in BC, including low market prices and high transportation and processing costs, challenging access to cutting areas with biomass trucks, and policy constraints impeding business-to-business opportunities for secondary utilization of residues. Next, timber cruising data were used to simulate residue production for 28 forest licenses across the province, using the FPInterface model. The analysis was carried out for the Coast, North, and South forest areas, and it was found that roughly 74 to 92% of merchantable harvest volume will be removed during harvest, while the remaining round wood will be left in the cutting area, along with the tops, branches, and foliage. It was also found that, of the total residue generated during harvesting, 69 to 80% will be delivered to the roadside for full-tree harvest systems. Finally, the investigation of alternatives identified 7 categories of alternative residue management practices which could feasibly replace SPB in the province. All the alternatives identified are expected to provide emissions reductions relative to SPB, while some also provide ecological benefits, or bioeconomy opportunities. This thesis demonstrates that current SPB emissions estimates are reliable, there are many alternative practices which can replace SPB in BC, and support will be needed to help promote a shift in management towards these more sustainable alternatives.

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Canada is home to 10% of the world’s forest and these forests play a major role in both carbon sequestration and storage and in supporting Canada in achieving its commitment to reducing greenhouse gas emissions by 30% by 2030 relative to a 2005 baseline. To date, Canada has largely overlooked the emission reduction opportunities that comes from using forest biomass for large-scale urban heating with district energy systems. By finding applications for forest biomass, a reduction in forest fuel accumulation or reducing natural losses is possible. Biomass-based heating technologies have long been deployed in Europe, particularly in European countries. However, in Canada there have been challenges to adopt large-scale biomass heating with concerns seeming to be centered around the capital cost feasibility and long-term forest sustainability. Using a case study approach, this project addresses these concerns through quantitively estimating the implications of managing forests for biomass fuels, an economic analysis of multiple supply chains for biomass procurement, and then finally a comparison of forest biomass with the community’s existing heating utilities. The study, which is in three phases, focuses on the delivery of wood chips from central Ontario to a potential biomass energy centre in Haliburton County. The first phase will be an analysis for the heat load demands of 4 distinct theoretical systems for Haliburton Village. The second phase will establish a baseline scenario according to the existing forest management practices, low-grade timber stock and the market climate for the local forest. The third phase will be a comparing the baseline in phase 2 with a shift towards managing the forest for more wood fuel. The results demonstrate the implications of: 1. Designing an appropriately sized district energy system 2. The economic analyses of different of supply chains available for biomass procurement 3. The changes in delivered cost biomass for the individual heating systems 4. The challenges and considerations that need to be made when establishing a supply chain. The results demonstrate a promising pathway to bioheat success, the impacts on the existing underutilized wood fibre market as well as an alternative fuel source for heat in Central Ontario.

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