Eddie Mills, age 9, of Hobart, Ind., for his question:
What is the timber line?
People who live all their lives on the flat and level plains never get to see a timber line. But this wonderful surprise is always waiting to be seen in high mountain country. You may find one way up a lofty mountain near the Equator or on almost any other mountain in the world.
Most high mountains wear caps of snow, summer and winter. Even Mount Kilimanjaro and other peaks near the equator wear snowcaps through the year. This is because the air gets colder as we rise higher above the level of the sea. As we cross the wide continents, we find warmer stretches of land in the valleys and on the plains and cooler stretches of ground as we go higher and higher up the sloping shoulders of the mountains.
Our wonderful world, of course, is clothed with a vast assortment of plants. And plants tend to grow wherever they can. Their tiny seeds struggle and try hard to make a go of it wherever they fall. But different plants need different things. Some need heat and lots of sun, others need shade and lots of moisture. Cacti can live in the hot, dry deserts, and scrubby mosses can make a living in the frozen north.
The biggest plants, as Everybody knows, are the trees. Big plants need lots of nourishment and trees must have deep roots to gather the liquid nourishment they need from the soil. They also need deep roots to hold up their mighty trunks and branches when the blizzards blow. So the trees do best in the valleys, on the plains and the gentle hills.
But like all other plants, they grow wherever they can, WE find them standing up and still higher up on the slopes of the lofty mountains. Higher still are the snowcaps, and snow means frost. No tree can prod its deep roots through the hard and frozen ground. And high peaks are windy places. Their shoulders are often bald rocks where the blizzards have blown away all the soil. No tree can grow here.
The lumbermen call the trees timber, and the timber grows as high up a mountain side as it can. Where the soil becomes too thin and the ground becomes too hard, the timber Ends. The place where the trees End is called the timber line. Higher up a few straggly bushes struggle to make a living, and higher still is the white world of the mountain's snowcap.
If you fly across our country, you will look down upon the tops of the western mountains. Many of them have snowy peaks and below the snow you can see forests of stately trees. The forests creep up from the canyons and way up the mountain the front row of trees suddenly stops at the timber 1.ine. For this line is as high as the trees can grow.