Options for Monitoring Urban Naturalization Success by Janice Ka Ching Lam
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Options for Monitoring Urban Naturalization Success By Janice Ka Ching Lam A thesis submitted in conformity with the requirements for the degree of Master of Forest Conservation John H. Daniels Faculty of Architecture, Landscape, and Design University of Toronto Table of Contents Executive Summary……………………………………………………………………...………..2 Acknowledgements………………………………………………………………………………..3 Background………………………………………………………………………………………..4 Engagement as Measure of Success………………………………………………..……..8 Problem Definition……………………………………………………………………………….10 Research Objectives……………………………………………………………………………...10 Methods…………………………………………………………………………………………..10 Historical Monitoring at the City of Toronto…………………………………………………….11 City of Toronto’s Planting Success Survey……………………………………………...13 Trees Across Toronto Protocol…………………………………………………………..16 Tree Advocacy Planting Program Monitoring…………………………….……………..18 Urban Monitoring Options……………………………………………………………………….19 TRCA – The Young Tree Monitoring and Maintenance Program………………………19 EMAN – Shrub and Small-Tree Stratum Biodiversity Monitoring Protocol…………....20 Vegetation Sampling Protocol…………………………………………………………...21 Tree Canada……………………………………………………………………………...21 Forests Ontario…………………………………………………………………...………22 Piloting Protocols………………………………………………………………………………...22 Modified VSP……………………………………………………………………………24 Modified YTMP…………………………………………………………………….…...27 Staff Feedback…………………………………………………………………………...31 Planting Event Survival Audit …………………………………………………………..33 International Monitoring Protocol Comparisons………………………………………...............35 Recommendations………………………………………………………………………………..36 Conclusion.………………………………………………………………………………………37 References………………………………………………………………………………………..39 Appendices……………………………………………………………………………………….42 J.K.C. Lam 1 Executive Summary Municipalities have strived to naturalize urban landscapes for decades through various tree planting initiatives. Furthermore, the degree of restoration success, its contribution towards increasing canopy cover and the creation of wildlife habitat is often unknown due to the lack of monitoring data. The City of Toronto has been facilitating volunteer tree planting events for over two decades and to rationalize their tree planting efforts, planting survival was examined. Historical data from previous monitoring programs such as Toronto’s Planting Success Survey, Trees Across Toronto and Tree Advocacy Planting Program were analyzed. Relevant local urban monitoring programs such as Toronto Region Conservation Authority’s Young Tree Monitoring and Maintenance Program (YTMP), Ecological Monitoring and Assessment Network’s protocol, and vegetation sampling protocol (VSP) was assessed. Trials of modified versions of VSP, and YTMP were also tested to develop a suitable monitoring program for the City of Toronto’s Natural Environment and Community Program group. Forest monitoring protocols from Italy, China, and Sweden were assessed, and long-term permanent sample plots are determined to produce the most reliable and scientifically rigorous data. It is recommended that municipalities use the Planting Event Survival Audit at the minimum and aim towards adopting a long-term permanent plot sampling program when funding and staffing allows. J.K.C. Lam 2 Acknowledgements I would like to thank everyone who has supported and contributed to my capstone project. Thank you to my internal supervisor, Dr. Danijela Puric-Mladenovic for her feedback, wealth of knowledge, and support throughout the report. I’d like to express my gratitude to Dr. Sean Thomas who guided me through the statistical background about survival monitoring and provided advice during the piloting phase. Thank you to my external supervisor, Lisa McLean who has been instrumental in initiating this monitoring project, in addition to field-testing data, and spearheading support for this project at the City of Toronto. Thank you to the City of Toronto’s Natural Environment and Community Programs team for their feedback and patience throughout the protocol testing phase; their input has been invaluable. I would like to extend my gratitude to Dr. Sally Krigstin and Amory Ngan from the City of Toronto Urban Forestry for making my summer internship possible. Thank you to Joe Renton for his help with GIS and sharing the monitoring protocol research conducted by Forests in Settled and Urban Landscapes Applied Research Group. Special thanks to Laura Hockley and Vincent Wong for editing this report and providing feedback! Lastly, thank you to all my fellow MFC students for providing support throughout the program. J.K.C. Lam 3 Background In recent years, communities within urban areas have striven to increase the amount of green spaces through ecological restoration and naturalization of areas. Ecological restoration is the process of assisting the recovery and management of ecological integrity (Evergreen, 2001). Naturalization is a type of ecological restoration that involves returning altered sites to a more natural condition using native trees and shrubs (Evergreen, 2001). The process of naturalization reduces the need for pesticide use while creating habitats, preserving biodiversity, improving air and water quality, reducing in the urban heat island effect, and moderating temperatures (Evergreen, 2001). The City of Toronto converted high maintenance sites such as turf grass using naturalization and community planting events. Public participation enables building community support and awareness while also fostering environmental stewardship (Evergreen, 2001). The City of Toronto has multiple community-based volunteer programs through which participants are involved in mulching, weed removal and tree planting. The movement coined “community naturalization” utilizes volunteer-based community groups to restore degraded urban lands and transform these sites into natural spaces (Chisholm, 2004). Such movements have instilled community stewardship and a sense of environmental awareness within Toronto’s communities. There are a multitude of benefits, beyond the aesthetic enhancement that city trees and natural areas provide. These trees and natural areas can aid with mitigating storm water runoff, moderating temperature fluctuation, improving the air quality and sequester carbon (Pothier & Millward, 2013). City trees are the best solution to manage urban stormwater runoff, urban heat island and air pollutants in the urban setting (McPherson, Simpson, Peper, Maco & Xiao, 2010). Each tree that is planted in the city can positively benefit their surrounding area. In addition, urban forests can increase the economical value of properties (Paileit, 2003). For example, a cluster of trees planted together can provide further benefits to the community and alleviate the human pressures and stresses on the urban environment. Tree solutions are more cost effective than the engineered alternatives and can create significant environmental benefits if maintained properly. Utilization of monetary value can allow forest management to justify the investment in urban forests and stewardship activities. The impact of urban trees can be better understood J.K.C. Lam 4 through quantifying their services through a monetary lens: properties benefit between $7 USD to $165 USD per tree each year through tree shading, water regulation, carbon reduction, air quality improvement, and noise reduction (Song, Tan, Edwards & Richards, 2018). For every dollar invested in tree management, the benefits returned an average of $1.37 USD to $3.09 USD annually (McPherson et al., 2010). However, city trees face a multitude of stresses due to the urban environment including soil compaction, elevated soil temperature, restricted rooting zones, salt sprays, and vandalism (Pothier & Millward, 2013). These factors create difficult growing conditions for urban trees and drastically decrease their growth rate and survival. Due to the harsh growing conditions, the mortality rate of newly planted saplings is often high. Many of the planted trees in urban environments do not survive long enough for residents to gain the benefits of the urban forest (Roman, 2014). The average life span of an urban tree is between 10 to 25 years, yet municipal political decisions do not prioritize the maintenance of trees (Pothier & Millward, 2013) to ensure that they will reach maturity. Large healthy trees can remove up to 60 to 70 times the quantity of air pollution in comparison to a newly planted tree (Pothier & Millward, 2013). Currently, 68% of trees that comprise of the urban forest in Toronto are less than 15.2cm in diameter (City of Toronto, 2013). Thus, most of the trees within the city are newly planted and only 13% of trees are greater than 30.6cm in diameter (City of Toronto, 2013). The potential for these young trees to grow and contribute towards the tree canopy cover and provide benefits is largely determined by the quality of maintenance they receive. Post- planting maintenance of newly planted trees is critical for their survival and establishment success (Moskell & Alfred, 2013). Tree care offers residents an opportunity to engage in environmental stewardship activities through the City of Toronto, such as watering and mulching, which increases the likelihood of saplings to establish themselves to endure city stresses. The City of Toronto prides itself on its reputation as a “city within a park” and boasts 10.2 million trees and a canopy cover of approximately 28% (City of Toronto, 2013). Outlined by Toronto’s Strategic Forest Management Plan 2012-2022, the canopy cover