“Trees play a vital role in shaping the well-being and sustainability of communities.”

Short Elliott Hendrickson Inc.

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Most Canadians live in a city or town; we don’t truly understand what the natural environment is and—perhaps more to the point—aren’t capable of relating to it meaningfully. Many of us have learned to ignore Nature, we stop recognizing it, we pocket it away as we go about our busy lives in the city. A park is a bit of greenery. A tree is a decoration that provides shade. Shrubs border a mall.”— Nina Munteanu “Climate Change and the Colour of Resilience”

But if we can’t even recognize the natural environment, how can we understand its functional role in the intricate well-being of this entire precious planet and ultimately ourselves? And without this, how can we pursue a sustainable life on this planet?

Many of us intellectually understand that city trees provide significant benefits to any urban environment. They: 1) help regulate the water cycle, particularly with stormwater absorption and flood reduction; 2) provide shade and reduce heat islands; 3) and they provide immense health benefits through connection. They also contribute to climate resiliency, capture carbon and help reduce greenhouse gas emissions.

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“A single tree can soak up to 22 kg of carbon dioxide in a year and produce enough oxygen to sustain two people.”

Short Elliott Hendrickson Inc.

If planted well, trees and their associated permeable surroundings reduce runoff, erosion and flooding. Their root systems help against erosion and help consolidate the soil to more effectively retain water and prevent slopes from slumping.

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“Runoff from an area covered in impervious surface is 5 times that of a forested watershed of the same size.”

Short Elliott Hendrickson Inc.

Trees, whether a single tree or a grove along a street, provide a wealth of well-being for humans, whether through habitat for birds, through chemical aerosols, or simple aesthetics. Many studies have shown the benefits of trees and associated green space and birds to human mental health. Scientists have proven that conservation of natural areas in urban settings is just as important for human well-being as financial security. Trees and forests provide habitat for birds; and birds give us joy. Birds help with mental health and mental acuity.

In Part 2 of “Why I Love Trees” I write about a study by Lancaster University that showed the birch tree’s detoxifying capabilities when they planted silver birch trees between a street of houses and a busy road. According to Professor Barbara Maher, the trees absorbed more than 50 per cent of the particulate dust — linked to respiratory problems — from passing traffic. The tree “is a chemical factory,” says botanist and biochemist Diana Beresford-Kroeger. They broadcast a host of chemicals into the environment that may travel for hundreds of kilometres, as well as affect the immediate area. Beresford-Kroeger argues that trees help maintain the health of the natural world, given that they constantly shower healing chemical mists into the air. “These substances are at the heart of connectivity in nature,” says Beresford-Kroeger.

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Planting and Maintaining Urban Trees

City trees must deal with lack of water, compacted soil, not enough food, physical injuries, imported pests and diseases, road salt and air pollution, soil compaction and restricted root space. Other considerations include suitability of tree species planted, when and where it was planted and how the individual tree is looked after.

Short Elliott Hendrickson promotes five key best practices for urban tree planting and maintenance:

Choose the right tree for the right location. Select tree species that are well-suited to the urban environment. This includes considering space, sunlight exposure, and soil conditions. It also means understanding which trees can tolerate salt, deicing chemicals, drought or prolonged water inundation, or pollution and others don’t. It also means understanding how some root systems can damage sidewalks, pipes, foundations, or buried utilities.

Space trees appropriate to their mature size. Plan for expected tree maturity. A tree’s maximum size and genetic characteristics should be considered to avoid future conflicts between roots and sidewalks, nearby vegetation, or power lines. A general rule of thumb, says SEH, is to allow at least 10 ft. of clearance between the tree and any overhead or underground utility lines, and at least 4 ft. of clearance between the tree and any pavement or building.

Incorporate innovative, ecologically sound elements: These include structural supports or organic mulch that protect trees and enhance their growth, while also improving the aesthetic appeal of the urban landscape. Use features such as soil cell tree pits and tree guards to support tree growth and protect them from urban stresses, such as foot traffic, vandalism, and construction activities. Soil cells use vertical recycled plastic structures that support a concrete sidewalk above while preventing soil compaction and root damage from vehicles or pedestrians. Granite mulch is a viable alternative to limestone mulch (that adversely alters soil pH) and not only enhances structural support, but also provides a neutral pH balance for the soil. It also helps retain moisture and suppresses weed growth around the tree base. However, granite mulch may raise soil temperature and reflect heat, which may not be suitable for certain tree species or in specific climate conditions.

Ensure proper soil mix, drainage, and air exchange: Plant trees at the right depth, Implement drainage systems, and provide adequate access to air exchange to ensure healthy root growth and soil health. Often, it’s not the lack of moisture that puts undue stress on trees, it’s the lack of available oxygen in the soil. By incorporating a system of aeration pipes and vertical ducts into the planting system, better and long-term tree health can be obtained. Using the correct balance of engineered soil mix will allow tree roots to thrive.

Regular monitoring and ongoing care: Implement regular oversight and maintenance programs to identify and address issues promptly. Monitoring includes measuring tree growth, health, and survival rates, as well as detecting signs of pests, diseases, or environmental stress. Maintenance may involve pruning, watering, fertilizing, mulching, or treating trees as needed. Monitoring and maintenance can be done by professional arborists, city staff, or trained volunteers. Regular monitoring and care ensures the longevity and vitality of urban trees and reduces potential risks or liabilities.

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“Urban trees are not just aesthetically pleasing but vital components of sustainable and resilient cities – responsible planning and preservation of trees within urban landscapes should be a top priority,” —Short Elliott Hendrickson Inc.

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