Nature in Tiny Technicolour!
By Paul Masterson
Once again the forests of Tiny are ablaze with brilliant colors as nature’s paint brush dabs, splashes and strokes hues and tones of yellow, brown, green, red and gold across the autumn landscape.
Strolling with his granddaughter on an afternoon in early October along a well worn trail in Awenda Provincial Park, Grandpa is describing how Jack Frost, using artistic exuberance, paints the forested landscape into scenes of technicolour splendour.
“The greens of summer, Brigid, make trees live and grow but now the reds and yellow of Fall warn the trees to stop growing and rest.”
Somewhat bemused, the fourteen year old smiles… “That’s a pretty picture, Grandpa, but our science teacher said that the red and yellow colors are already in leaves, but are hidden by the green during the growing season. The green is a pigment called chlorophyll. It makes food in the leaves using water, nutrients and the sun’s energy. When the leaves start to die the green disappears and the other colors show up.”
“Grandpa, did you know that some people think that a good frost is needed to make this change in color?
Not waiting for a response, Brigid explains… “it’s the colder temperatures and shorter light days of Fall that makes it happen. Teacher said a severe frost can kill the green tissues which destroys the multicolored effect leaving leaves black or brown.”
The protest of a startled grey squirrel catches their attention as it scurries up a tree.
Wanting to regain her grandfather’s attention, Brigid taps him on the arm and continues … “Grandpa!… My teacher also said that because of the shorter days and colder weather, trees grow a corky layer of cells across the bottom of the leaf’s stem. This shuts off the water and minerals that feed the chlorophyll and it starts to break down. As the green fades, the other colors show up. Pretty soon the leaves fall from the trees.”
Pleased by how much she remembered, Brigid warms to the discussion and becomes the “teacher”, continuing… “Mr. Kingston used science words for the color stuff, Grandpa.”
“Mr. Kingston?” inquires the old gentleman.
“My science teacher, Grandpa,… He said the pink, red and purple colors are from a pigment called antho…cy….anthocyanins. I remember its blue because a primary color I learned in my art classes was cyan, which is blue.”
“The yellow and brown colors come from pigments called carotenes… tannin and… ah…anthofile’ or something like that.”
“I think the word is ‘xanthophyll’, Brigid. If my Greek serves me right, xanthous’ means yellow… ‘phullon’ or phyll is leaf.
“Gee, Grandpa, I didn’t know you studied Greek? Did you see the movie ‘Zorba the…’?”
“Pardon, Brigid?…”
“Just kidding, Grandpa.”
Continuing her recitation, Brigid recalls… “I remembered carotenes because its the same pigment found in carrots, and tannin is used to tan leather.”
The path by this time has led them to a vacant picnic area edging a maplebeech grove and bordering the weedy shore of a small lake. A rustic sign reading “Second Lake” swings in a light breeze that ripples over the spring-fed lake.
Absorbed by the pleasant scene, Grandpa draws Brigid’s attention to the striking colors of a nearby maple tree saying… “I would guess that tree is about 60 years old,… half the age of the maple in your backyard at home. A professional forester friend told me that a 60 year old maple can shed over 200,000 leaves in a year; that would weigh about 120 lbs or… ahm… 55 kgs.”
“Wow, no wonder Dad grumbles about raking leaves.”
“Grandpa, how many leaves would a forest of trees drop each year?”
“Well, my Forester friend did say that on one acre of a 30year old mixed forest of hardwood trees, you know, broadleaf trees … you know broadleaf trees like that maple … over 10 million leaves weighing 3000 lbs. would fall. That would be 1360 kgs. in metric.”
Although enjoyable, it had been a long walk. A heavy sigh by grandfather is noticed by the youngster. Concerned that he might drop like the leaves he was describing, she suggested they rest as she pointed to a nearby log. Comfortably settled, Brigid asks … “Grandpa, what else did your friend tell you about trees and their leaves?”
“Oh… probably some things that your teacher explained in class, Brigid… like… well… that the forest is more than trees. That in and under its leafy cover other life exists in many forms.”
At that moment the raucous chatter of several blue jays disturbs the woodland peace…..
“There for one! Birds… and animals, insects, mosses… shrubs… bushes. Some are readily seen… others are millions of very tiny or microscopic creatures thriving in the forest floor. These creatures are responsible for most of the work that turns leaves and other vegetation(0*0*0*into humus and nutrients… which in turn are fed on the by trees and other plant life.”
The light dims momentarily as a cloud drifts across the late afternoon sun… This shaded moment strikes a thought in Grandpa which he expresses…
“Fall is not the end of life for trees but is just one episode in their annual life cycle. Beautiful because of the exciting colors, bracing air and brilliant sunny days… Fall, at the same time, is sad for some of us, as it marks the passing of summer. Even so, keep in mind, it’s only a stage in the continual cycle and renewal of nature’s life.”
“Leaves die and fall, Brigid, the trees and other forest vegetation rest for the winter, but before this happens, they leave behind next year’s beginnings of renewed life in the form of buds… millions of them.”
Picking up a stick at his feet, Grandpa pensively scratches at the ground where they are sitting.
“Brigid do you notice anything about the forest soil or how fast things grow at this time of year?”
Brushing her foot across a carpet of leaves baring the soil beneath, she pauses… then answers.
“Well… the ground is certainly covered with lots of leaves, Grandpa. The other day, Dad said that with the shorter and cooler days, the grass isn’t growing as fast… not like it grew in July or after rainy days in August.”
“That’s true, Brigid, one last cut this month and the lawnmower can be put away until next spring.”
Reaching down he took some soil from the spot that Brigid bared and rubbed it between his fingers.
“Even though there may be less rain now, the ground around the root systems is quite moist because growth has slowed and stopped. The trees, bushes and shrubs without leaves are now resting. They no longer need the tons of water pulled from the earth through their roots during the spring and summer.”
“It’s hard to imagine but a tree, like the 60 year old maple over there, will have transpired 7,500 lbs [3,400 kgs.] of water since the spring…”
The granddaughter cuts in… “Transpiration by the leaves is something like what humans do when they perspire. Isn’t that so, Grandpa?”
“Yes, there’s a similarity, Brigid.”
Drawing a deep breath and with his granddaughter snuggled beside him, he asks…
“Tell me Brigid, did your teacher discuss how trees produce oxygen that freshens the air about us.”
“Oh sure Grandpa, we talked about that and the tropical rain forests and……”
Grandpa interrupts, patting her knee. “I’m referring to what happens here in Canada and northern countries like Canada… Did you realize that over the next 7 to 8 months of colder weather while they rest in this dormant stage, trees and other plants will produce no oxygen… and this happens year after year?”
Somewhat startled by this idea, she reacts… “Does that mean there is a much bigger source for oxygen, Grandpa?”
“Well dear, when you go back to school ask your teacher where we get the oxygen we need if their are no leaves on the trees, shrubs, bushes for most of the year in Canada.”
“Do you know, Grandpa?”
Yes, but I’d rather your teacher tell you or show you where to find the answer. We’ll talk about it later. One other thing, Brigid. Remember the 30 year old mixed forest that my friend talked about?”…
“The hardwood forest, Grandpa?”
“Yes… Well, he said, during the growing season it will take 350 lbs. of nutrients from the soil and will return about 240 lbs. in leaves and twigs.”
“My goodness Grandpa, your Forester friend really knows a lot about trees and the forest…”
“That’s his business, Brigid. Foresters were the first professional conservationists to put science to work in managing the forests of Ontario and Canada.”
As the chill of late afternoon blankets them, Grandpa turns and, lightly pressing his hand over Brigid’s ears now tinged with pink, saying… “It’s really cooled quickly and I don’t think your ears want to hear much more. What do you say we head home?”
References: “Focus on Forests” Ontario’s Ministry of Natural Resources Canadian Institute of Forests, Southern Ontario Section
