City Trees is a premier publication focused on urban + community forestry. In each issue, you’ll learn how to best manage the trees in your community and more!
Issue link: https://read.dmtmag.com/i/36513
pests and diseases is very much out of our control given the nature of travel and global trade. What is within our control is the manner in which we plan for the eventuality and respond to the unwanted visitors when they come knocking on our door. We’ve had consistent, ongoing support that has allowed us to maintain vigilance through monitoring and forecasting for biological threats to the urban forest through our forest health care program. In 2007 and 2008 we successfully implemented a control program for the European gypsy moth that included egg mass removal as well as ground and aerial spraying with the biological control agent Bacillus thuringiensis subspe- cies Kurstaki (Btk). Under the program we sprayed 320 ha (791 acres) with Btk using a low-flying helicopter and we removed egg masses from over 3,500 trees. Approximately 100 trees were treated with Btk from the ground. The result of this proactive integrated pest management approach was a drastic reduction of the European gypsy moth population to acceptable levels. Additional control measures have not been necessary since 2008. ALHB was first found on the border between Toronto and the neighbouring municipality of Vaughan in 2003. Since then we have worked in successful partnership with the lead agency, CFIA, and other federal, provin- cial, and municipal partners in the effort to eradicate ALHB. Since 2003 approximately 27,000 host trees have been removed in Toronto and Vaughan as part of the eradication program. Tree replacement funded by the CFIA, MNR, and City of Toronto has mitigated this loss of tree canopy through replacement planting initiatives. Monitoring for ALHB has continued and no viable life stages of ALHB have been detected since the summer of 2007. We are hopeful that full eradication of this pest can be announced within the next few years. In response to the spread of EAB, we have continued our partnerships with CFIA, CFS, MNR, and other agencies with a view towards acquiring more scientific knowledge about the dynamics of EAB and mitigating its impact. What is the status of Toronto’s tree planting program? We’ve implemented an aggressive tree planting program over the past five years to ensure tree planting exceeds the number of trees that are removed. We currently plant over 100,000 trees each year using our own staff as well as contractors. We also provide many opportunities for the public to participate in tree planting through the use of planned events. Finding appropriate planting sites on public lands will become more difficult over time, and we need to continue to encourage property owners to plant trees on private property wherever possible. Within sidewalks there are many competing interests for space which would traditionally limit tree planting. Community planting event within a Toronto river valley. Five major watersheds run through Toronto, and there are many smaller tributar- ies associated with each. www.urban-forestry.com 13