Diario del proyecto EcoSpark Participant Observations

A post shared by EcoSpark intern Philip Harker

Trees! Who doesn’t love them? Here in Ontario, much of our land is covered in trees
year-round. In fact, 66% of the province’s land mass is forest [1]. Pretty amazing to
think about, especially for those of us who live in urban and suburban communities!
Trees are perennial species. This means that, once planted, they will stay alive for many
years, to include the summer and winter seasons. In Ontario’s cold winters, trees slow
down or even entirely halt photosynthesis (the production of food), with some going so
far as to completely shed their food factories (their leaves) [2]. This strategy allows trees
to save their energy for spring, when they can grow their leaves back relatively. Trees
that lose their leaves in the winter are called “deciduous trees”. Other trees, called
“coniferous trees”, have leaves that take a lot of resources to grow back if lost.
Coniferous trees have evolved to hold onto their leaves, as it makes more sense to hold
onto them through the winter than to spend most of the spring and summer growing
them back.

When walking through Ontario’s beautiful forests in the winter, take some photos of the
trees that you see. It can be very difficult to tell them apart, but there are a few key
clues to look for.

Bark
Tree bark does not change appearance throughout the year. Bark texture and colour
can be great ways to identify trees in the wintertime. Birches and beeches have a
distinctly smooth bark, whereas oaks and sugar maples have jagged and fractured
surfaces. Birch trees are characterised by their off-white bark with black spots, and red
oaks have a slightly— you guessed it— red hue.

A birch tree such as a paper birch (Betula papyrifera) has a very distinctive bark.

Photo: eknuth/iNaturalist [3]

Physiology
Just like humans, no two trees are alike. They have evolved to grow and develop in
different shapes and sizes. Despite the individual differences from specimen to
specimen, each tree species has some physical characteristics. Oak trees will have
thicker and fewer branches, maple trees will have thinner and denser branches, and
birch trees will be skinny, with branches well above the height of your head.

Fruit
All deciduous trees are part of a larger group of plants called “angiosperms”—the most
diverse group of plants on Earth. One of the defining traits of all angiosperms is that
they all produce fruits. Not all deciduous trees will produce prominent fruit in the winter,
but keep an eye out. You might see bright red berries of the winterberry (don’t eat
them, they’re quite toxic). These are small and soft. Larger berries could belong to the
hawthorne trees, but those are a bit harder to find in Ontario.

Winterberries are easily identifiable by their fish egg-like appearance.

Photo: zachbaranowski/iNaturalist [4]

Expert Referral

If you’re uncertain about a tree, snap a photo and post it to Ecosparks’ iNaturalist
page. Even if all you can confirm is whether it is deciduous or not, it won’t take long for
iNaturalist’s tree experts to make the identification for you.

Philip Harker is an undergraduate ecology student at the University of Toronto.

Citations
[1] https://www.ontario.ca/page/state-ontarios-natural-resources-forest-2021
[2] https://carnegiemnh.org/how-do-trees-survive-the-winter/
[3] https://www.inaturalist.org/observations/5116631
[4] https://www.inaturalist.org/observations/67590216