On November 9th, 2016, some of the Éco-quartier NDG staff went to see a presentation called ‘ Why Forests Matter’ presented by the Toronto Dominion (TD) Bank Friends of the Environment programme.
Despite my training in biology and ecology, I learned quite a bit at this presentation. Some of it was so interesting to me, I felt that I needed to share it with the NDG residents, many of who are also passionate about trees.
Most of us know that trees store carbon absorbed from the atmosphere. That is why it is so important, especially with our current air pollution, that we keep as many trees on Earth as possible to help with air quality. What I had never thought about however, is that wood products (products made from trees like benches) also store carbon. In storing carbon, trees also help to protect our waterways from carbon pollution, and thus trees indirectly help with maintaining amphibian populations and therefore, maintaining biodiversity. Some of the benefits that trees provide: they absorb carbon dioxide (CO2), they make oxygen, they protect wildlife, they moderate temperatures and they purify water. This process is better known as ‘natural capital’.
Another thing that I learned about trees at the presentation, and also on the TV programme La Semaine Verte, is that there are ‘mother trees’ and younger trees. It seems that fungi connect all trees together in an underground network. It is a symbiotic (mutually beneficial) relationship where the fungi give energy to the trees, and in return, the trees offer the fungi carbon. Through this underground network, the mother trees can help the smaller seedlings grow by sending them carbon and water. The situation reverses itself when the mother tree grows old and weak, mother trees will receive water from their kin. If the situation seems hopeless and the mother tree is injured, she will send even more carbon to her kin as she dies off.
The fungal network has also been shown to carry nutrients far into a forest. In British Columbia, bears eat the salmon that are swimming upstream. Many bears choose not to eat right next to the river, but carry their fish a little bit into the forest to have a quiet meal. Scientists have analyzed the trees of these forests, and learned that the fish bones left behind provide the trees with calcium and other nutrients. There is a fluctuation of salmon nutrients in the tree rings, likely based on how much salmon was carried into the forest in any given year. The surprising thing that scientists discovered, was that the salmon nutrients were distributed far into the forest, even to trees that were not near the river. They realized that it was the underground fungi network that was distributing the nutrients throughout the forest.
It seems that having trees around is not only a benefit to the environment. It has been proven that people do better when there is biodiversity in park, allowing them to enjoy a variety of plant, tree and animal species. It is therefore very important that we protect our trees in Montreal. Who knows what else we will discover in the coming years about the fascinating world of trees!