Healthy Trees, Healthy People

    by Sally Cole


    “Many people think that urban nature is nice to have, that it’s pretty or a bonus.  But actually, it’s absolutely essential to our mental and physical health,”

    — Professor Carly Ziter, urban landscape ecologist, Concordia University. [1]



    Forest bathing is a recognized practice in Japan’s national health program.  Known as shinrin-yoku, forest bathing is mindful time spent under the canopy of trees for health and wellbeing. Trees and plants release phytoncides, airborne chemicals that help them to ward off insects and fight disease and that also emit antimicrobial essential oils with medicinal properties. Forest bathing is a form of aromatherapy.  Breathing forest air boosts the immune system, reduces blood pressure, lowers cortisol levels and improves concentration and memory.  Walking in trees also reduces depression.  Neuroscientists have found that metabolic activity in the subgenual prefrontal cortex — the part of the brain that is activated when a person is having sad thoughts – decreases by going for a walk in the woods. A walk on city streets does not have the same positive effect.


    Dr. Qing Li, President of the Society of Forest Medicine in Japan and author of The Art and Science of Forest Bathing, describes forest bathing as a “preventative medicine.”  His advice for a walk in trees is to “Make sure you have left your phone and camera behind.  You are going to be walking aimlessly and slowly.  You don’t need any devices.  Let your body be your guide.”


    In Britain “social prescribing” is a growing movement. The National Health Service (NHS) now recognizes a range of non-medicinal therapies and activities that doctors can prescribe for their patients’ wellbeing.  These social prescriptions include gardening, volunteering and cooking.  The Woodland Trust and other citizen’s groups are advocating for the NHS to add forest bathing to the list.


    In Denmark, preschool children have thrived at forest schools since the 1950s.  Richard Louv in his book Last Child in the Woods links the increasing numbers of children with health conditions such as attention deficit hyperactivity disorder (ADHD) to their limited access to nature in urban and even suburban contexts.  Education amidst trees is now known to have huge psychological benefits for children and forest schools have become a global movement.

    A peaceful walk among the trees at Westmount Summit.

    Connecting with Trees

    Healthy mature stands of trees are webs of connectivity. “Trees are social beings.  The forest is a social network,” says German forester Peter Wohllben in his best-selling book The Hidden Life of Trees.  Spending time with healthy trees is also participating in their lively social life.


    Trees link to other trees through mycorrhizal networks.  Fine, hair-like root tips of trees join together with microscopic fungal filaments to form the basic links of the network.  Fungal threads link nearly every tree in a forest.  Fungi consume about 30% of the sugar that trees photosynthesize from sunlight.  Fuelled by “tree sugar,” fungi then scavenge and absorb nitrogen, phosphorus and other minerals from the soil and transfer these nutrients to trees through their roots. Mycorrhizal networks may supply plants and trees with up to 40% of the nitrogen and 50% of the water they need to survive.  And trees may exchange with other trees between 10 and 40% of the carbon they store in their roots.  As a tree ages, its mycorrhizal network develops more and more fungal connections and its roots grow deeper and deeper into the soil.  Older and bigger trees with deep roots draw up water and circulate nutrients to younger or weaker seedlings.  Interspecies networks of cooperation assist adaptation to environmental stresses and changing conditions.


    Trees send carbon through mycorrhizal networks not only to trees that have grown through the same root system but also to “companion” species.  For example, cedars and maples form networks that share nutrients as do hemlocks and firs.  McGill University’s Morgan Arboretum preserves a healthy “maple sugar bush,” a network of trees comprised of ash, hickory and basswood growing among the sugar maples.


    Trees have evolved to “help their neighbours” says Suzanne Simard, professor of forest ecology at the University of British Columbia and author of the bestseller, Finding the Mother Tree.  When the biggest, oldest trees are cut down, the survival rate of younger trees is reduced. Trees live longer and reproduce more often in a healthy forest of stable underground mycorrhizal networks.  Suzanne Simard describes an old-growth forest as an “ancient and intricate society” of trees, plant undergrowth, fungi and microbes that communicate with one another in symbiotic partnerships, the health of all depending on each.



    Future Forest Bathing on Meadowbrook

    Worldwide, citizens are urging their city councils and urban planners to pay attention to preserving trees and increasing accessible green spaces in urban areas.  The proven positive effects of preserving trees and plants offer a simple and cost effective way to improve the quality of life and health of urban residents – and thus the social sustainability of cities themselves.


    The city of Montreal plans to plant 500,000 trees by 2035 to increase its tree canopy to 25%.  The prairie on Meadowbrook offers the city a special opportunity to build on existing stands of century-old silver maple, white elm and basswood trees and to re-naturalize this 57-hectare urban green space and increase biodiversity in the city.


    Meadowbrook’s handsome mature trees are indigenous to the Great Lakes-St. Lawrence Forest Region, and offer ancient nesting sites to ducks, resting places for migrating birds and dens for squirrels, raccoons and other mammals.  Other indigenous species such as burr oak, black cherry, ironwood, bitternut hickory and shagbark hickory grow along the railway tracks that bisect Meadowbrook.  There are also several introduced species that are now naturalized in Canada including Norway maple, Siberian elm and crack willow. Re-naturalizing Meadowbrook would allow the planting and thriving of other tree species that were once native to the region including dogwood, vibernum, hawthorn, serviceberry, white elder and dogberry all of which produce small fruit to feed birds and other fauna.


    AND, enhancing the tree networks and connectivity of Meadowbrook’s stands of mature trees will offer an accessible public space for Montreal residents to enjoy the healthful practice of forest bathing!



    [1] Hoag, Hannah. This is Your Brain on Trees.  Globe and Mail. April 17, 2021


    The End of the Lawn

    by Sally Cole


    The lawn is an invention of the English landed gentry living in the foggy, moist climate of the British Isles. Lawns proliferated across Canada with the mass development of suburbs in the 1950s and 1960s. [1] However, lawns are unsuited for most North American ecozones.  Fertilizers, pesticides and frequent watering are necessary to keep grass green.  And maintaining lawns brings the noise and pollution of lawnmowers.  It is an illusion to think, that because lawns are green, they are somehow natural and do not adversely affect the spaces they occupy.


    Scientists have found that lawns actually produce heat.  Lawns produce more greenhouse gases than they absorb.  Urban planners actually refer to lawns as “heat islands.” Green spaces comprised of lawn are 20% hotter than green spaces with a diversity of vegetation, trees, creeks and wetlands.  Urban green space planners have determined that Montreal’s “nature infrastructure” (infrastructures naturelles) is primarily lawn. Planners are urging the city to re-naturalize its green spaces in order to help the city adapt to climate change and global warming. [2]


    A typical North American lawn is comprised of one grass type.  It is a monoculture: it does not provide a biodiverse ecosystem for a web of species of flora and fauna to support each other and create healthy soil.  Re-naturalizing replaces lawns by planting a diversity of plants, grasses, shrubs and trees.  Increasing the biodiversity of the nature infrastructure will not only reduce heat production in the Greater Montreal area but it will also improve air quality, control flooding and offer recreational spaces for the physical and mental health of citizens.


    Words from Gardeners Who have Re-naturalized their Lawns   

    This re-naturalized lawn in western NDG features a lot of milkweed.


    Seeking to increase biodiversity in the city’s green spaces, Toronto is planting pollinator gardens in municipal parks and has established a program offering $5000 grants to create pollinator gardens.  Dr. Nina-Marie Lister, director of the Ecological Design Lab at Ryerson University, has re-naturalized her Toronto front lawn with over 100 species of indigenous trees, shrubs and plants (including milkweed, bone set, black-eyed Susans, buttercups, forget-me-nots, and lambsquarter).  Professor Lister describes the plants in her garden as “hard at work” creating:  “Birdsong, cricket song, pollination and habitat for a wide range of species – our garden provides a lot of services for the neighbourhood,” she says.  The garden holds storm water, controls run-off, provides a habitat for a variety of birds and at-risk insects like monarch butterflies, homes for frogs, rabbits and chipmunks, education for school groups, and respite for passers-by who like to sit and relax on the logs and breath the fragrant air. [3]


    UQAM professor of forest ecology, Dr. Christian Messier has re-naturalized his garden and lawn in Lachine and offers some tips for Montrealers. [4] He reminds us that we live in a temperate deciduous forest ecozone.  Before European settlement, the land was a diverse hickory, oak and maple forest.  He advises us to choose perennials, leafy ferns and native shrubs that would originally have grown in this temperate forest ecozone and that will offer colourful blooms throughout the changing seasons:


    In spring:  trilliums, elderberry, violets, dwarf dogwood, early meadow rue, chokecherry, jack-in-the-pulpit.

    In summer: foam flower, red baneberry, raspberries, false Solomon’s seal and several species of ferns including maidenhair and Clayton’s fern.

    In late summer and early fall: fireweed and asters.

    In fall: “Just let the leaves fall!” Professor Messier advises. Rather than raking leaves, “I prefer to read a book,” he jokes.  The fall leaf cover provides nutrients to the soil. As the leaves decompose, they store carbon in the plants and replenish the soil and reduce the amount of carbon in the air. “In grass, carbon exists only in the first 5 centimetres; in the forest floor, there’s more than a metre of carbon,” he says. “And in the spring, the plants will go through the leaves.”


    Gardener extraordinaire, David Somers, has helped many NDG-ers to re-naturalize their lawns.  “My joy is to destroy grassy lawns and replant with indigenous (and other) plants,” he says. [5]

    Here are his five favourite indigenous plants for Montreal gardens:


    In shade:  Northern Maidenhair fern, Canadian anemone and Canadian wild grape (for ground cover)

    In sun:  Phlox and thickly-planted New England aster


    David Somers adds a ‘like’ for the great mullein or common mullein:  “not native but introduced with colonization centuries ago and still usually considered a weed,” he says, “but striking when well-placed in a garden. It is a hairy biennial plant that can grow to 2m. tall or more.”

    A small and sunny corner of the Elizabeth Ballantyne school yard in
    Montreal West has been transformed into a wildlife-friendly habitat.



    see also The American Lawn (1999) edited by Georges Teyssot.  Published in conjunction with the 1998 Canadian Centre for Architecture exhibition of the same title “The American Lawn.”  Co-published with Princeton Architectural Press.

    [2] La Fin du gazon:  Où et comment complexifier les espaces verts du Grand Montreál pour s’adapter aux changements globaux Fondation David Suzuki. 2018



    [5] author email correspondence with David Somers, Feb.4, 2021 and March 5, 2021

    St. Pierre River tragedy- last open portion of the historic Montreal river is buried on the Meadowbrook golf course

    Les amis du parc Meadowbrook, released a press release on Feb. 24, 2022 with photos to document this tragic event. The photos were taken Feb. 19-20, 2022.

    Construction crews hired by the City of Montreal are currently burying the last open portion of the St. Pierre River on the Lachine side of Meadowbrook. See the press release for details.

    The storm sewer newly connected to the Toe Blake Park collector which was the source of the St. Pierre River. The riverbed, which can be seen in the bottom right of the picture, no longer has any flow as all the river water is now being bypassed through the storm sewer which will soon be completely buried.

    This is one of the few segments of the St. Pierre River storm sewer pipe that had not been buried yet on Feb. 13, 2022. It is right in the middle of the golf course as can be seen by the beautiful winter scene in the background. All that will remain of the river water will be manhole covers at intervals across this greenspace.

    This picture shows the small amount of frozen water remaining in the St. Pierre riverbed. A large pile of rocks and soil from the digging of the trench for the storm sewer looms over the river. Thankfully City workers assured us that the riverbed would not be filled in and that all soil not used to bury the sewer would be removed.