Mark Bowslaugh, age 8, of St. Catharines, Ont., Canada, for his question:
Where do the fallen leaves go?
The first winter wind strips the dead dry leaves from the branches. Down thcy swirl and cover the ground with rustling carpets of brown. Then comes the snow, and the fallen leaves arc buried under a white blanket. Spring brings warm breezes and sunbeams. But when the snow melts away, the buried carpet of fallen leaves seems to have vanished.
The woods and the wide outdoors belong to the world of nature. And this world of nature is run by rules of give and take. Last year fallen leaves give what they can to enrich the soil. The green buds of spring take nourishment which they need frown the rich soil. This give and take goes on in the world of nature without any help from us.
The rain and the snow, the soil and the changing seasons help along the story of the fallen leaves. Tiny mites and even smaller bacteria also help nature to clean up the dead leaves and put them to proper use. Bit by bit, those old leaves arc changed into chemicals and mixed with the damp soil.
Plants, of course, do not eat our kind of food. They use sunlight to make their own sugary food from the air and fern the water in the soil. They also need special minerals or chemicals which arc dissolved in the water that their roots take up from the soil. As the leaves grow, they use these minerals to build tiny boxed called cells. A leaf is made from thousands of these small plant cells all fitted together.
The cells of the growing leaves are filled with juicy sap. When they grow old and fall, the sap dries out and their colors fade. But the leaves are still made from boxy plant cells, and the vaus of these cells are made from plant food and chemicals taken from the soil.
The ground teems with tiny mites of all, kinds and bacteria too small for our eyes to see. These little creatures get busy in the rusty carpets of fallen leaves. They chew and eat, digest and dissolve the dry plant cells. The chemicals in the leaves are broken down into simple minerals which plants use for food.
The rains and snows dissolve these minerals and sink into the soil. The roots of the trees reach around stud soak up the water with its load of mineral plant foods and send it way up to the twigs and branches. There it is used to feed the new crop of leaves.
The fragile maple leaves and the fallen oak leaves may disappear before spring. The tender sections go first, and, for a while, the ground may be strewn with leafy skeletons. These threads are the tough veins of the leaves, but soon they too disappear. Spiky pine needles are very tough and may litter the ground for five or six years. But at last they, too, are broken down by mites and bacteria, and their minerals disso1ve in the soil.