by Deborah Mesher, Architectural Designer and Wendi Li, Arborist with Elite Tree Care
Deborah: What is a protected tree?
Wenda: Trees located on private property with a diameter of 30 cm (12 inches) or greater are protected within the City of Toronto’s Private Tree By-law. This means a tree removal permit is required to remove any private tree with a diameter of 30 cm or greater, even if you planted it yourself! The diameter of the tree is measured at 1.4 metres (4-1/2 feet) from grade level. Protected trees also include all trees of any diameter situated on the municipal property or on the municipal right-of-way, as well as trees of all diameters situated on ravine protected land which are protected within the City of Toronto Ravine and Natural Feature Protection.
Deborah: How do renovations or additions impact trees?
Wenda: Root loss and root damage are the most common types of construction related damage to trees. Digging near a protected tree, such as excavating for a new foundation, walkway, or patio will impact tree roots. Similarly, soil compaction, caused by repeated construction traffic, will damage tree roots by compacting the soil and removing the vital air pockets important to retain oxygen and water for the tree roots to grow. Damage to tree roots will impact the tree’s health and stability. Tree branches in close proximity to construction activities can also be damaged as the result of the passage of equipment and machinery. Protected trees can be pruned prior to the commencement of construction to provide appropriate height clearances to the development activities. The City of Toronto has specifications to protect trees during construction. An arborist report for construction development is typically required to identify protected trees for preservation or removal. The report also includes tree protection measures to minimize the impact of construction to protected trees. It is best to consult with a certified arborist during the early stages of a development project.
Deborah: What do arborists do?
Wenda: An arborist is a professional that specializes in the care and maintenance of trees. They are able to advise on optimal tree care practices which can include tree pruning; tree and stump removals; fertilization and soil aeration/amendments; installation of tree support systems like cabling and bracing; tree planting; and the treatment of insect and diseases. Utilizing specialized equipment and gear, arborists typically work at height. In the urban landscape, trees require regular maintenance to promote and to maintain tree health and to provide adequate clearances from building structures and utilities. Dead, diseased, or structurally compromised trees may necessitate removal. During storms, arborists are called upon for highly technical and hazardous removals to mitigate potential risks posed by fallen trees.
When looking for an arborist, it is strongly recommended that they are certified. The most recognized certification is an ISA (International Society of Arboriculture) Certified Arborist.
Deborah: What other specialized services do arborists offer?
Wenda: Trees which are impacted by construction sometimes require an investigative root survey to determine the extent of potential root loss due to the proposed excavation within the Tree Protection Zone. A specialized pneumatic tool, e.g. Air Spade, is used to blow the soil away to expose structural roots with minimal root disturbance. This type of exploratory root assessment can better determine the viability of root injury on a protected tree.
Deborah: Why are trees important in Toronto?
In the urban environment, trees play a vital environmental and ecological role by improving air quality; cooling the effects of urban heat islands by shading; and promote biodiversity by supporting wildlife, bird, and insect habitat. Toronto is also known for its green spaces, and trees provide people with that connection with nature and is also known to enhance a person’s health and well-being. Trees also aid in stormwater runoff and prevent soil erosion. As a part of Toronto’s green initiative, the City of Toronto has a goal of reaching 40% tree canopy coverage by 2050.
Deborah: What do you wish homeowners knew about trees?
Wenda: Trees are a breathing, growing, living organism.
Learn more about Elite Tree Care here.