On Tuesday February 5th, a small crowd gathered in the Noel Ryan auditorium of the Mississauga Central Library for the first of 2019’s Lecture Me! series. Delivered by Professor Andrew Almas from UTM’s department of Geography, the talk, titled “Considering the Human Dimensions of the Urban Forest,” explored his research on how much residents really know about urban forestry.
Urban forests are the ensemble of greenery planted in urban milieus, from backyards to parks to sidewalk trees. He marks the distinction between the study of urban forests as Geography—a Social Science, and not forestry, which is concerned with forested area as opposed to urbanized areas. According to Almas, urban forests not only provide us with ecosystem services, but are the only form of greenery we interact with as Southern Ontarians. The importance it holds in our lives allows municipal governments to increase their awareness of the value of urban forests, and are busy determining ways to better manage them.
Almas’s talk encompassed the pros and cons of planting native vs. non-native tree species, residents’ attitudes towards urban forestry, and how having a municipal urban forestry management plan influences an area’s urban forest. According to Almas, Mississauga is among the few cities in the GTA with an urban forest management plan (UFMP). Typically, the plans span a period of approximately 20 years and have goals such as increasing canopy cover and educating citizens on what the best urban forestry strategies are. However, they are not presently achieving the latter goal. Since half the trees in urban forests are on private land, there is no way to properly affect change but through the cooperation of residents and business-owners.
As part of his research, Almas explores the difference in preference for native versus non-native plant species in municipalities, both ones with a UFMP and without. He discovered that municipalities with a plan had a preference for native species, for the sake of safeguarding the ecological integrity of urban forests. Specialist species breed more ecological interactions. On the other hand, there are academics who argue for the planting of non-native species, as urban forest eco-zones are wildly different from natural forests. They argue that they may also fare better against environmental stressors. However, most of this research comes from Scandinavia, where native species are sparse. In contrast, Southern Ontario has 80-90 species native to it.
Despite the UFMPs’ preference for native species, they also recognize that eco-zones will change in the coming years. Research shows that Southern Ontario will have the same eco-zone as Northern Florida by 2080. Considering this, it would be wise to practice a phenomenon known as assisted migration—in other words, planting non-native trees in urban forests. However, there is no guarantee that climate change will pan out as predicted. There is also the risk of migrating trees becoming invasive.
Invasive species have been a real menace to urban forests in the past century. Starting with the Chestnut Blight in the early 20th century, a series of invasive insects have eaten through native Canadian trees and endangered our canopy cover. The Chestnut Blight wiped out over a billion chestnut trees and Dutch Elm Disease eliminating 70 per cent of elm trees. Following this crisis, ash trees were planted in bulk, as they were considered the ideal street tree in nature and stature. Despite this, in the early 2000s, the Emerald Ash Borer caused 20 per cent of Southern Ontarian canopy to die.
Planting trees in bulk turned out to be bad management practice, as entire streets were then scarred, not to mention the two billion dollars in economic loss. The ecological loss was crippling as well, as ecosystem services such as carbon sequestration and air filtration were compromised. Almas explains that the current threat to our canopies is the Asian Longhorn Beetle—should this take hold, we would have an economic and ecological catastrophe on our hands.
With the importance of native tree-planting in mind, Almas conducted research on residential attitudes towards it. Knowledge levels on whether a species is native or non-native turned out to be low, regardless of whether the subject lived in a municipality with a UFMP. This would suggest that the management plans are not yet fulfilling their aspired roles as educators on the subject. The surveyed population was 98 per cent in favour of planting native trees, regardless of any hazards associated. Higher levels of education and time spent in Canada both increased their favour for native tree-planting. When it came down to what they planted, though, residents chose non-native species—for the shade they provided, their aesthetic, or their level of maintenance.
There are private tree laws that protect noteworthy species, as well as blanket protection laws over all tree species—a permit must be obtained if a certain number of trees are cut down, and those trees must be replaced (the specific details vary). Often, neighbours do not report each other if these requirements aren’t fulfilled, and the government did not make it a practice to check. It is therefore imperative that municipalities invest in community education and outreach on the subject. In terms of the Mississauga Central Library, they have partnered with an organization named Ecosource and offer programs that educate people on the city’s urban forestry initiatives.
Lecture Me! was a series started as an opportunity for researchers to expose their work to the public, and as an opportunity for the public to have free access to research. This was the fourth of seven lectures to be delivered this academic year, all located at the Noel Ryan auditorium in the Central Library of Mississauga, on the first Tuesday of each month, from 7-8:30 p.m. Previous lectures have addressed how the fourth industrial revolution may be shaping how we live, and teaching the classics through the contemporary (with a specific focus on Dante). The next lecture will be held on March 5th, by Professor Lawrence Switzky of UTM’s Department of English and Drama, on the possible personality benefits of playing video games.
Almas teaches Environment and Geography courses here at UTM. Courses he has taught include Environmental Justice and The Sustainability Imperative.