Last week our kayak club launched from Henley Island in Martindale Pond, Port Dalhousie. First we crossed the “pond” just north of what will be the rower’s finish line area during the Niagara 2022 Canada Summer Games. We paddled into the mouth of the third Welland Canal’s Lock 2 for some local history, and then followed the east shore of the pond to the Royal Canadian Henley Rowing Centre starting gates. The sun was shining, a gentle breeze provided cooling air, and we were able to troll the spectacular back yards of many luxurious homes from our water-level vantage points.
Yet it was when we entered Richardson Creek, a narrow ribbon of meandering Kahlua-brown water surrounded by and overhung with beautiful indigenous trees, that a tranquil hush settled over the paddlers. Our attention was captured by the nature around us. Birdsong was everywhere, sunning turtles plopped into the water as we approached, and the fragrance of wild lilac filled the air.
Why do forests and natural environments captivate so many of us, and are the benefits of being surrounded by trees as significant as claimed by countless health professionals and advocates? The Richardson Creek kayaking experience and coincidental receipt of a May 2021 Statistics Canada Health Report caused me to ask these questions.
The Stats Can report stated, “Living in a home surrounded by trees, gardens and natural vegetation (i.e., greenspace, or greenness) may confer numerous health benefits. Notably, studies in Canada, the United States and Europe have found inverse associations between residential greenness and all-cause or non-accidental, respiratory and cardiovascular mortality.”
For the record, the purpose of the Stats Can report was to quantify and draw attention to the fact that ethnocultural and socioeconomic disparities in exposure to residential greenness within Canadian urban communities needed to be remedied. Pelham and Niagara are blessed with a surfeit of green compared to the inner-city communities studied by the report; consequently this column is not intended to engage in a political and urban planning debate.
The result of further investigation into the mental and physical health benefits of a green environment, and specifically trees, was eye-opening. There is no end to the number of published and peer-reviewed studies supporting those claiming benefits. In June 2020, Kathleen L. Wolf published an overview for the American National Centre for Biotechnology Information on “Urban Trees and Human Health” to facilitate further research. The preamble to her report states, “Following screening and appraisal of several thousand articles, 201 studies were chosen.” This suggests the positive health claims are scientifically factual rather than the work of tree-hugging advocates.
The New York State Department of Environmental Conservation states that, “Exposure to forests boosts our immune system. While breathing in fresh forest air, we inhale phytoncides, airborne chemicals that plants, especially pine, cedar, fir and cyprus trees, give off to protect themselves from insects. These phytoncides have antibacterial and antifungal qualities which help plants fight disease.”
Our bodies respond to these chemicals by increasing the number and activity of our white blood cells called natural killer cells or NK, which attack tumor and virus-infected cells in our bodies.
Researchers from the Nippon Medical School in Tokyo found that blood analysis after volunteers did a three-day, two-night forest expedition “showed a remarkable increase in the NK cell activity which also lasted for a month afterwards. Even a one day forest trip showed an increase in these cells.”
The United States National Forest Foundation agrees. They claim the reduction in stress that forests provide us is linked to lower levels of the stress hormones cortisol and adrenaline, which is also linked to quicker recovery and rehabilitation in those suffering illness and injury.
The arrival from Asia of the Emerald Ash Borer devastated ash tree populations in Niagara and throughout North America. By doing so, the EAB provided a natural experiment which proved the value of our tree cover to human health. A 2013 study published in the American Journal of Preventative Medicine concluded that across 15 states, tree cover destruction attributable to the Emerald Ash Borer was associated with an additional 6,113 deaths related to lung disease and 15,080 heart-disease-related deaths.
The day trip to the forest park significantly reduced blood pressure and urinary noradrenaline and dopamine levels
Walking amongst trees affects blood pressure too. In 2011 a team of Japanese researchers studied 16 male subjects, average age 57 years old, as they walked for two hours in a tree-filled urban park in Tokyo, then for a similar duration in an urban area void of vegetation. They found, “The day trip to the forest park significantly reduced blood pressure and urinary noradrenaline and dopamine levels.”
The mental health benefit of spending time in nature has also been the subject of many research studies. The POMS (Profile of Moods State) test is a self-administered quiz of 65 questions that is frequently used to evaluate workplace environments for employee satisfaction. When the POMS test was administered to those engaged in forest trips, subjects showed significant decreases in depression, anxiety, anger, fatigue, and confusion. Since these types of stress inhibit immune system function, it appears the mental benefits of time spent in nature also generate physical benefits.
A two-year study by researchers in London (UK) published in the Journal of Landscape and Urban Planning discovered that locales in London “with the greatest density of trees had the lowest rates of antidepressant prescriptions. Researchers went as far as to discover that each additional tree per square kilometer resulted in approximately 1.38 less antidepressant prescriptions.”
The indirect environmental and climate change prevention benefits that trees and forests provide to humans are well known, but bear repeating to complete this picture. Trees are second only to ocean phytoplankton as the largest producers of the oxygen we breathe.
Forests purify water for thousands of communities across North America that source their drinking water from treed watersheds. Tree roots assist in soil conservation and prevent significant amounts of sediment from reaching our rivers and streams.
That trees absorb carbon dioxide to produce oxygen during photosynthesis is well known. The ability of trees to store this greenhouse gas in their wood and leaves is less recognized, as is the fact that trees transport atmospheric CO2, carbon monoxide and sulfur dioxide into the soil, thus reducing greenhouse gasses and pollution.
I’m convinced. No more bike trainer or treadmill in the basement between April and November for me, and regardless of the many shade trees lining Haist Street and Pancake Lane, in future I’ll choose the Steve Bauer or Jerry Berkhout trails. The climate-controlled walking track at MCC is great for January, but as long as there are leaves on the trees, the science says outside is where most of us should get our 10,000 steps in each day.
It’s all about the trees. ◆
