Welcome to my forest. It is autumn, so it is very wonderful here.
All the animals, including squirrels like me, are busy getting ready for winter.
Look around you and you will see that the leaves on the trees have changed colors.
The maple trees have turned bright red, and the elm trees have turned brown and yellow.
Have you ever wondered why the green leaves change into so many different colors?
Well, in the spring and summer when the leaves are fresh, they are filled with something called chlorophyll.
Chlorophyll is the natural coloring in the leaves that makes them green.
In order to make food, trees need energy from the sun.
Chlorophyll collects the energy from the sun and stores it in the leaves.
The leaves use this energy to make a liquid sugar, called sap, that the trees use for food.
The trees spend the spring and summer producing food so that they can grow bigger.
During the summer months, the trees get taller and wider and they grow more branches and roots.
But most importantly, the trees use their energy to grow nuts and fruits for animals like me to eat.
At the end of the summer, things begin to change.
It becomes cooler, and there is much less sunlight during the day.
Chlorophyll needs the sunlight and cannot survive in the cold weather.
So in the autumn when the weather becomes cool, the trees can no longer make chlorophyll.
When this happens, the leaves lose their green color.
When the green chlorophyll disappears, the leaves' other colors can be seen.
Trees like elm, birch, and poplar show their yellow and light orange colors.
These colors were in the leaves all summer, but because of the green chlorophyll, we could not see them.
Some trees, however, get new bright colors in the fall.
For example, maple trees turn bright red, and sumac trees turn dark red.
These trees get their color from red pigments that build up in the leaves when the sap stops flowing in the fall.
These pigments turn leaves red, pink, and even purple.
This natural coloring occurs in trees and other plants.
It gives some vegetables, like beets and radishes, their red color.
It is also what makes some flower blossoms red and pink.
The red pigments come into the leaves during cool, dry, sunny days.
I love to go running through the trees, looking at all the colors.
Even on the same tree, not all the leaves have the same color.
On some trees, the top leaves are bright red, but the bottom leaves are almost yellow.
This is because the top ones get more sun.
On trees near a river, the leaves are not bright because trees that get lots of water do not usually have colorful leaves in the fall.
But way up there on the top of a mountain, the leaves get lots of sun and little water, so they are very colorful.
Even from year to year, the colors of the leaves change.
When autumn is dry and cool, the leaves will have brilliant, shining colors.
But when the autumn is cloudy and wet, the leaves will not be as beautiful.
The autumn leaves are beautiful to look at, but they don't last very long.
Without chlorophyll, the leaves cannot live. Soon the leaves must fall off the branches onto the ground.
But this is good for squirrels because we love to play and jump in them.
When all the leaves have fallen from the trees, the animals know that winter is coming.
We hurry up and pack away all our food, and then we tuck ourselves in our little houses and go to sleep for the winter.
The trees also sleep during the winter.
Eventually the leaves that fall from the trees decay and turn into soil that is used during the following years as fertilizer for the trees.
You see, one of the beautiful things about nature is that everything works in a cycle.
The trees wake up in the spring with fresh new leaves.
These leaves grow in the summer, fall in the autumn, and then are turned back into soil so that more leaves can grow the next spring.
With the help of chlorophyll, the trees get bigger and stronger every year.