Part 11 (1/2)
1. Fires destroy an enormous amount of valuable timber every year.
2. Between fires and lumbermen our forests are disappearing faster than they are growing.
3. Fires destroy the young trees, and if they happen often enough will keep them from growing up to replace the mature trees.
4. Fires do not permanently help the cattle ranges, but injure them by burning the humus and gra.s.s seeds.
5. Fires leave the ground bare, so that it will dry out quickly.
6. Fires leave the soil unprotected, so that it will wash away quickly.
7. Fires destroy property and endanger lives.
CHAPTER NINETEEN
EVILS THAT FOLLOW THE DESTRUCTION OF THE FORESTS
We have already learned something about the poverty of the people in those lands where the forests have been destroyed. This poverty is due not so much to lack of wood for fuel and other purposes, but to a whole series of troubles which the removal of the forests has brought upon them.
The burning of the humus, when a fire sweeps the forest, is the next greatest loss to that of the timber itself. Where there has been no fire, the ground under the trees is covered with decaying leaves and stems which are slowly mixing with the soil and becoming a part of it.
The more there is of this humus in the soil, the more thriftily plants will grow.
Many people purposely burn over their pasture lands in the fall, believing that this will make the gra.s.s better the following year. They should know that every time this is done the soil is made poorer, and that it kills the seeds lying on the ground ready to sprout when the warm spring days come. Instead of a better pasture there is more likely to be a crop of almost worthless weeds. The ground is full of worthless seeds which are always ready to take the place of the gra.s.ses when they have a chance.
Before the fire came, the roots of trees, bushes, and gra.s.ses kept the earth from was.h.i.+ng; and the humus helped to hold the rainwater from running away rapidly, so that more of it had time to soak into the ground. How well this is shown on yonder hills which were once covered with brush. A fire swept over these hills and burned every living thing.
What a barren appearance they presented after the heavy winter storms!
The slopes were completely covered with little furrows and gullies where the rainwater had done its work. It will be a long time before vegetation will again gain a foothold there and stop the was.h.i.+ng of the earth.
When a fire occurs in the dense forests of the Cascade Range, all the trees are killed and the thick layer of decaying vegetation underneath is burned. The spruce, which is one of the most important lumber trees of this region, does not at once spring up again. Its seeds may be scattered there, but the soil is not now in a condition to nourish them.
In its place springs up the tamarack pine, which, because it can grow in poor soil, has the whole burned area to itself.
If we should return to the same place perhaps one hundred years after the fire, we should find that the tamarack pines had formed a thick forest. The lumbermen have little use for the tamarack and so have pa.s.sed it by. In looking carefully through the tamarack forest, we find that other trees are now springing up. They are already struggling for the food, the moisture, and the sunlight which the tamaracks are making use of.
During the many years that have pa.s.sed since the fire swept this region, decaying vegetation has been slowly acc.u.mulating and forming humus again. Now at last the seeds of the spruce find the soil rich enough again to sprout and grow. Here and there are thrifty young trees which will in a few years grow up and choke out the tamarack. Thus the tamarack, though of so little value itself, has done a great work in preparing the soil for a new growth of the valuable spruce.
Upon the drier slopes of the Western mountains shrubs, such as the manzanita and chaparral, spring up and cover the surface after a forest fire. Nature does not seem to want the surface left bare and usually has something at hand, even though it be nothing better than brush, with which to clothe it again. As the years pa.s.s humus begins to collect upon the ground and finally restores it to much the same condition it had before the fire. Now, if by any means seeds can reach such places, scattering trees will first spring up in favored spots and, after a time, the trees will become thick enough and large enough to shade the ground and the brush will be killed out.
[Ill.u.s.tration: _American Forestry_ The work of the water where the forest has been cut away.]
The cutting of the forests, especially from the steeper mountain slopes, has in many parts of the world changed water, one of Nature's most valuable gifts, into an agent of destruction. Throughout the Eastern and Southern states the floods are higher in spring and lower in summer than they used to be, because of the removal of so large a part of the forests that once covered this whole region.
In the West it is even more necessary that the forest cover be disturbed as little as possible. One reason is that the greater part of the forests are found upon the lofty mountains in which the streams rise. If we deforest these steep slopes, water is going to injure them much more than it would the gentler slopes of the lower lands, if they had been deforested. Another reason is that since little rain falls in the summer in this region, we must do nothing to lessen the summer flow of the streams, which is so much needed for irrigation.
[Ill.u.s.tration: _American Forestry a.s.sociation_ This beautiful valley in the Southern Appalachian Mountains has been ruined by the floods due to cutting off of the forests upon the headwaters of the river.]
The more water that can be held back in the mountains of the West for summer use, the more prosperous the farmers are. There is nothing that helps to hold the water better than the forests. They help to equalize the flow of the streams so that the floods are not so high in the spring nor the water so low in the summer as they would be if there were no forests.