Page:Popular Science Monthly Volume 79.djvu/333

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CIVILIZATION AND VEGETATION

farm and garden; but individuality has been sacrificed for safety, they have been conquered in the war which every man is waging against every other living thing, human or other.

Whether the Ishmaelitic rôle of man in nature be right or wrong, it is very real, and we can not escape playing our share in that rôle. It may be merely as competitors against other human beings, holding the positions which others would like, but which we call ours; or it may be as competitors against other kinds of organisms.

On beautiful spring days, when the country calls us from desk and laboratory, we see the fields turning over under the plow, the wild flowers, the native shrubs, and the young trees existing, if at all, only in the fence corners, the trees and other plants of the wood-lot leaping their bounds only to be killed bye and bye by the cultivator. In place of the variety which once covered an acre, we shall presently see only a waving field of grain, wheat or barley or oats, no one of which is native; or there will come up corn in formal rows which can reach its hypertrophic maturity only by the destruction of numberless smaller plants of which this field was once the possession. Or the unnatural trees of an orchard shade a hillside on which once stood a forest, and in place of clear streams the air tinkles with the music of brooks and creeks turbid with soil and perhaps infected with typhoid.

This last is an evidence of revenge. Civilization and man do not have things without struggle, although the outcome of the struggle is certain. Civilization and man will triumph, but not without great mortality on both sides. In the natural forest and on the natural prairie, untouched by man's invasion or by fire or by other profound disturbance, the balance is fairly maintained year after year. Last summer in the northern Rockies, I was struck by the fact that the forest does not encroach on the grass land, nor this spread into the timber. Generation after generation, they are the same, with great grassy bays here and there into the forest and high capes and promontories of timber stretching out into the grazing land. The trees and the grasses bear and shed seed year by year; insects eat the foliage or tunnel bark and wood; parasitic fungi cause smut or rust or rot; but neither set of enemies produces an epidemic or decimates the plant population, nor does the population greatly change. But let man clear the land of its stable native population, and the difference is at once apparent. If he attempt to raise a crop, he must fight as a weed every native plant, or cut back the timber to secure sunshine; he must drain his fields of excessive moisture, but in such manner as to conserve enough; he must till so that fresh soil may be brought to the roots of successive crops; and he must soon begin the endless use of insecticides, fungicides and fertilizers because of the apparently sudden increase in enemies and decrease in fertility. This is what he pays for trying to substitute his balance of