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Urban Trees in Vancouver : Mapping the Potential for Tree Canopy Improvement across City-Owned Properties Laramee, Nicholas Apr 6, 2016

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Urban Trees in Vancouver: Mapping the Potential for 
Tree Canopy Improvement across City-Owned Properties By Nicholas Laramee 
Report prepared at the request of the City of Vancouver, 
in partial fulfilment of Geog 419: 
Research in Environmental Geography, 
for Dr. David Brownstein. University of British Columbia April 6th, 2016 1Executive Summary:   The purpose of the project is to compare, through the use of maps, the potential for canopy improvements across Vancouver city-owned properties. My work  was done in partnership with the City of Vancouver, and was aimed to focus on three Vancouver neighbourhoods: Downtown Eastside, False Creek Flats and Marpole. This project argues that the City of Vancouver ought to increase the cover of the tree canopy on the majority of its lands. However, according to my maps, I recommend that the city look into increasing the tree canopy in the False Creek Flats first, since it is in this neighbourhood that I found the most locations with a high/very high potential for canopy improvement. Increasing tree canopies on various city-owned properties would have beneficial impacts on humans and the ecosystems. This is in agreement with the Vancouver Action Plan of 2020, in which the city not only aims to become the greenest city in North America, but also set a goal to plant over 200,000 new trees. This project, and the maps it provides represent additional tools the city of Vancouver may use in order to achieve their environmental goals. The research of this project was conducted through on-site assessments and a thorough literature analysis. The variables it considered included luminosity, available space for growth, water accessibility and human restrictions. Finally, my results, on top of the maps, depict the variability in the potential for canopy improvements across Vancouver properties and indicate some patterns that may be useful in further development.  2Urban Trees in Vancouver: Mapping the Potential for 
Tree Canopy Improvement across City-Owned Properties    This project aims to identify city-owned properties in Vancouver where ecological improvements, such as additional trees and various vegetation management strategies may be considered. Through the use of maps, the project also intends to indicate the potential for improvements at specific locations in respect to the space available. Throughout the last decade, Vancouver has really evolved into one of Canada and North America’s “greenest” cities. This is partly due to the plentiful green sites, such as parks, and the generous uses of vegetation in the city. Vancouver has also plenty of empty spaces where city improvements such as the planting of additional trees, the management of tree canopies and implementation of green spaces may help contribute to the urban ecosystem’s health. In fact, the “greenness” of the city not only revolves around implantation of additional trees, but also on the proper environmental management of particular city-owned properties. The purpose of the project is to compare, through the use of maps, the potential for canopy improvements across Vancouver city-owned properties. This project argues that the City of Vancouver ought to increase the cover of the tree canopy on the majority of its lands. In fact, a literature review on urban ecology offers a wide range of useful information on the project’s feasibility. However, before starting to implement ecological improvements we must analyze which of the available sites represent the most suitable environments. Then, we may further explore the potential improvements such as how many trees can be planted to maximize their growth within those sites. In order to efficiently look into the project’s goals, we must first look at the relevance of considering urban ecology. Then, the 3primary goal is to classify the suitability of city-owned properties. This may be done by looking into the literature on urban environments and their classification. Finally, we may look into the literature on the potential ecological improvements that we may consider for specific locations. Literature Review:  First, it is necessary to explore the context, relevance and potential critiques of looking into urban ecology. The presence of trees and the greatness of biological diversity in various sites across Vancouver allow its citizens to appreciate a sense of nature on an everyday basis. In fact, the numerous benefits of green sites within an urban area are well illustrated in multiple studies. For example, multiple researches show the values of trees within a city; they offer a range of benefits such as psychological, aesthetic and health related (Tyrväinen, et al. 2005); they contribute to a richer urban biodiversity (Bassuk, et al. 2009); and they regulate street level climate (Shashua-Bar and Hoffman, 2000). Some may critique the benefits of urban ecological improvements by arguing the financial negative consequences of such developments. However, a study conducted in 2004 shows that practical problems, such as allergies caused by some plants and cultural preferences, were bigger concerns to the population than were financial issues (Lohr, et al. 2004;Fraser and Kenney. 2000). The authors explain that people who strongly agreed that trees were important to their quality of life “rated the benefits of trees more highly than people who did not strongly agree.” So, the benefits of ecological improvements shown through these articles may validate this project regarding similar concerns in Vancouver. 
4 Vancouver may indeed profit from ecological management of some of its city-owned properties. Yet, before looking at those environmental improvements, we must look into another important part of the literature on urban environments reflecting on the “developability” of city-owned properties (Németha and Langhorst, 2014). In fact, it is necessary to analyze the availability and suitability of urban sites in order to suggest potential environmental improvements. 

 One category of city-owned properties where the potential for ecological management is at its highest consists of vacant lots. The concept of ecological development in vacant sites is explored thoroughly by the authors in the previous article (Németh and Langhorst, 2014). The authors focus on classifying available urban properties according to their uses, and the benefits of improving such sites ecologically. This is supported by another article which explains that urban vacant lots represent an “important natural component of every dynamically evolving city” and is an indication of healthy growth potential (Berger, 2006). These articles are relevant to the city of Vancouver because, according to on-site assessments, over 100 city-owned properties do not show evidence of city usage. The article presents three types of public vacant spaces: remnant parcels of land, reserved parcels, and contaminated parcels. These categories may be useful in this project regarding the suitability for ecological improvements within empty available locations. Another article supports the benefits of making use of the “remnant parcels of land” for environmental and economic reasons (Poole, 2004). The author demonstrates that, even small parcels, have the ability to produce significant benefits by addressing the inter-5connectivity between parcels of land and how they operate within a system that connects them to other lots with similar functions and performances.  Another important category of city-owned properties that may benefit from further ecological improvements is the developed lands. These include lots where buildings, parking areas and other developments, such as community gardens, already occupy most of the space. Some developed properties may lack environmental assets, and may benefit from further ecological management according to the literature (Sommer et al, 1994). This is relevant to the city of Vancouver because, according to the city action plan for 2020, it aims to plant approximately 6000 trees on public properties, excluding parks and streets, within 5 years (City of Vancouver. 2012). Sommer, R. et al. also explain that developed properties are often sources of high heat emission due to large pavement surfaces. Yet, ecological improvements of such locations may benefit the city. In fact, other studies examine the effect of  tree canopies on ground albedo modification (Oke 1978; Geiger 1965). They conclude that raising albedo can reduce both ground surface temperatures and upward flows of heat from paved surfaces. This is also supported in another article based on empirical evidence and numerical models exploring the cooling effects of green areas in their surrounding areas (Honjo and Takakura, 1990-91). This particular article also concludes that smaller green areas with sufficient intervals are preferable for effective cooling of surrounding areas. This supports the projects aim to manage ecologically small parcels of land that the city may environmentally neglect. Oke, Geiger, Honjo and Takakura also suggest that a broader tree canopy represents an efficient way of increasing the 6albedo on ground surfaces. This contributes to the project by helping to classify developed public properties into their potential for further ecological improvements such as a larger tree canopy.   
 By exploring the availability of city-owned properties, we also briefly mentioned some potential canopy improvements. The literature on this aspect of urban ecology may help this project not only map the different classification of city-owned properties, but also offer a more precise mapping according to their ecological needs and benefits. According to studies on urban ecology, one important ecological need that most city sites can thrive on is ecological biodiversity (Hough, 1989; Niemelä, 1999). In fact, the authors argue that the design and management of urban land may increase the richness of diversity of ecological, social, cultural and educational purposes. They explain that urban design within city landscapes should be ecologically productive, thus increasing biological and social diversity. They also suggest that one way of doing so is to efficiently manage the tree canopy. This illustrates the relevance of examining urban trees in order to increase urban biodiversity.  The need to expand urban biodiversity also includes the necessity to examine the local conditions of specific sites in order to determine the ecological potential at each location. One important variable explored in the literature on urban ecology looks at the ground qualities, such as soil conditions. In fact, the fertility of the land, for example, represents an important variable, and needs to be sufficient in order to yield and maximize the growth of planted trees. As studies show, too little or inadequate soils may lead to the premature death of newly planted trees (Bullock and Gregory, 2009). Another important variable in determining the capacity of growth 7for new trees at the studied sites is the access to water, nutrients and light. In fact, tall buildings nearby and concrete ground material surrounding some sites may impact the water and light availability for new trees. This is further explored in a report by the city of Toronto conducted in 2013 by multiple consultant firms (DTAH,  et al. 2013). The report explains that light input, for example, strongly affects the growth and yield of some tree species. On top of supporting the need to examine local environmental conditions, the report also states the necessity to prioritize human needs regarding the localities. The report provides the example of busy street corners where additional trees may decrease visibility for drivers, thus increasing the risk of accidents. Finally, the report presents environmental goals similar to most ecological objectives presented in the Vancouver Action Plan (City of Vancouver. 2012). In sum, the literature shows that urban ecology represents a valid and efficient approach to multiple ecological improvements the city of Vancouver may consider. It also indicates the suitability for various sites, which helps to classify those according to their “developability”. Vacant lots and already developed properties are both discussed, within the literature, as major sites for ecological consideration. This will help answer the project’s question regarding the classification and mapping of various city-owned properties in Vancouver. Finally, also according to the literature, we have discussed the benefits of increasing the biodiversity and tree canopy within the city. This validates the second part of my research regarding the potential environmental improvements the city may consider at specific locations.8Method:
 As we have discussed, the literature review shows that the concept of urban tree densification represent a valid and efficient approach to multiple ecological improvements the city of Vancouver may consider. The literature also explores the conditions indicating the suitability for various sites, which helps classifying those according to their “developability”. In order to simplify the mapping of locations, the project focuses on the three major conditions, drawing from the literature, when looking into the ecological potential at every site: soil condition (coarse/fine, clean/contaminated, types of material), growth capacity (available growth space and light input), and restricting localities (i.e. limited visibility at street corner). These conditions will be examined during on site assessments of each city owned properties. 
 However, some properties will not be examined during the research. In fact, this project focuses on the vacant and developed urban properties, such as parking lots and buildings, but purposely omits city parks. In fact, vacant lots and already developed properties are both discussed, within the literature, as major sites for canopy improvements. But, city parks represent highly complex ecological systems and require further onsite biological and scientific research in order to be analyzed. Thus, for the purpose of this project, the neighbourhood maps will focus on vacant lots and developed city-owned properties.   On the maps, I used dots to locate sites. I also used a colour scheme in order to represent their ecological potential regarding future tree canopy management. Dark green dots represent 9locations where the potential for canopy improvements are the highest. Light green dots represent sites where the canopy is very poorly managed, but there are some constraints regarding space, light, soil condition or human restrictions. Yellow dots mostly represent poorly managed canopy with high constraints in local conditions. Orange dots represent well managed canopy with possible further improvements. Finally, red dots represent very well managed canopy or extremely constraining localities. I decided to use the potential for improvement as the classification system because of its positive aspect in the analysis. An opposite classification system such as the actual canopy management by the city of its properties may offer a negative critical approach to their current management system. Also, some locations may have been under construction during on-site assessments, therefore need further analysis in the future. These uncertain location are identified by a grey dot. Results:  In map 1, I have represented every city-owned property in Downtown Eastside with the use of a dot. I have then classified these dots according to the local environmental and social conditions discussed in the method section. Most dark green dots appear on the Northeast side of the neighbourhood. These are either vacant lots or sites with very poorly managed canopy. There is also a large cluster of light green dots around Main St. at the bridge to the highway. These are sparsely vegetated areas which would benefit from additional urban trees. Most of the other locations are represented by red dots. These are often buildings at proximity of the rest of Downtown Vancouver. The proximity of the buildings, streets and landmarks limit further 10canopy improvement. In fact, this neighbourhood depicted a clear pattern between high-rise buildings and low potential for canopy improvement. This pattern is also visible in some locations in the other maps, but not as clear as in Downtown Eastside.    11Map 1: In map 2, I have gathered information regarding locations in the False Creek Flats. This area is closely related to the previous one (Downtown Eastside), yet offers a different range of data. In fact, the ratio of “Very High” or “High” to “Very low” or “Low” is greater in this neighbourhood. In fact, as depicted in map 2, there is a greater ratio of green dots compared to red dots. This indicates the greater potential for canopy improvement in the False Creek Flats, compared to Downtown Eastside. The area also has the highest potential in comparison to Downtown Eastside and Marpole. In fact, when addressing issues in regards to tree canopy cover, I would suggest looking into the False Creek Flats first. 12Map 2:  In map 3, I depicted city-owned properties and their potential for canopy improvement in Marpole. This map is limiting in its depiction due to the low number of city-owned properties in the neighbourhood. However, some of the locations depicted do have a “High” to “Very High” potential. These locations consist mainly of oddly shaped and often small parcels of land. In fact, it is in these locations that this area may improve its canopy cover most efficiently. Some of these parcels of land already have vegetation on them, but further management may be required in order to maximize the presence of tree. 

13Map 3:Conclusion:    Through the use of maps, the project also intends to indicate the potential for improvements at specific locations in respect to the space available. I argue Vancouver ought to increase the cover of the tree canopy on the majority of its lands. However, if we look at all three maps, we see that most of the locations offer a very low potential for canopy improvement. This is in part due to the fact that the city already manages relatively well its urban trees, but also that some ares have a low chance of success for trees and further increasing their canopy. However, further research may be helpful in considering other solutions that may be environmentally viable. In fact, a system of analysis based on different levels of canopies (low, medium high) may be explored in the future. Also, the research could expand the species of interest to all kinds of plants that may thrive more in some areas. For example, in Downtown Eastside, most locations have a poor access to sunlight during the day. Yet, some species may still live with a limited access to UV if other variables, such as water and nutrients availability, are more accessible. This project, was aimed at the cover of tree canopy, and focused on the potential to increase it. However, in future projects, other variables may be useful to consider, such as trees species and nutrient supplies. This would further help the City of Vancouver achieve its goals towards the Vancouver Action Plan of 2020 and towards a sustainable future. 
14References: 1. Bassuk, Nina, Deanna F. Curtis, BZ Marranca and Barb Neal. 2009. Recommended Urban Trees: Site Assessment and Tree Selection for Stress Tolerance. Urban Horticulture Institue, Department of Horticulture, Cornell University, New York. 
2. Berger, Allan. 2006. Drosscape: Wasting land in urban America. New York: Princeton Architectural Press. 3. Bullock, Peter, P. J. Gregory, and British Society of Soil Science. 2009. Soils in the urban environment. 1st ed. Oxford; Boston. Blackwell Scientific Publications. 
4. DTAH, Lead Consultant; ARUP, James Urban. 2013. Tree Planting Solutions in Hard Boulevard Surfaces. Project # A21065. Recipient: City of Toronto.
5. Fraser EDG, WA. Kenney. 2000. Cultural background and landscape history as factors affecting perceptions of the urban forest. Journal of Arboriculture 26, 106-112. 
6. Geiger, R. 1965. The Climate Near the Ground, Harvard University Press, Cambridge, 
MA.
7. Honjo, T. and Takakura, T. 1990-91. Simulation of thermal effects of urban green areas on their surroundings areas, Energy and Buildings, 15-16:443-446. 
8. Hough, Michael. 1989. City form and natural process: Towards a new urban vernacular. New York;London;: Routledge. 
9. Kathy. Poole. 2004. Potentials of landscape as Infrastructure Part 1: Six and a half degrees of infrastructure. J. Raxworthy, J. Blood (Eds.), The MESH book: Infrastructure/landscape, RMIT Press, Melbourne.
10. Lohr, Virginia I., Caroline H. Pearson-Mims, John Tarnai, and Don A. Dillman. 2004. How urban residents rate and rank the benefits and problems associated with trees in cities. Arboriculture & Urban Forestry 30, (1). 
11. Németh, Jeremy and Joern Langhorst, Rethinking urban transformation: Temporary uses for vacant land, Cities, Volume 40, Part B, October 2014, Pages 143-150. 
12. Niemelä, Jari. 1999. Ecology and urban planning. Biodiversity and Conservation 8 (1): 119-31.
1513. Oke, T. R. 1992. Boundary layer climates. 2nd ed. New York; London: Routledge. 
14. Shashua-Bar, L and ME Hoffman. 2000. Vegetation as a climatic component in the design of an urban street. An empirical model for predicting the cooling effect of urban green areas with trees. Energy Build 31: 221-235. 
15. Sommer, R., F. Learey, J. Summit, and M. Tirrell. 1994. The social benefits of resident involvement in tree planting. J. Arboric. 20:170–175. 
16. Tyrväinen, Liisa, Stephan Pauleit, Klaus Seeland, and Sjerp de Vries. 2005. Benefits and uses of urban forests and trees, in Cecil Konijnendijk, Kjell Nilsson, Thomas Randrup, Jasper Schipperi (eds), Urban Forests and Trees, 81-114. Berlin, Springer. 
17. City of Vancouver. 2012.  The Greenest City 2020 Action Plan. Action plan for city of  Vancouver. Web. http://vancouver.ca/files/cov/Greenest-city-action-plan.pdf. Accessed on Jan 28th, 2016.  16

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