Page:Popular Science Monthly Volume 11.djvu/404

388 Much more unaccountable seems our own indifference to the disappearance of our forests, since our science has demonstrated to the satisfaction of all rational and semi-rational beings—including some very conservative rulers of Western Europe—that an animal flayed, or a tree stripped of its bark, does not perish more surely than a land deprived of its trees.

The Duke of Burgundy's rule, "One-third to the hunter, two-thirds to the husbandman," expresses about the most desirable proportion of woodlands and cultivated fields. In a country blessed with such a plethora of woods as the United Stales between the Atlantic and the valley of the Mississippi could boast of less than a hundred years ago, the work of "clearing" could therefore be pursued within very liberal limits, not only without injury, but with positive benefit to the climate, inasmuch as it would counteract excess of moisture and miasmatic tendencies. But in some of our Southern and Central States this limit has already been passed. The States of Ohio and Indiana, and the southern parts of Kentucky and Michigan, so recently a part of the great East-American forest, have even now a greater percentage of treeless area than Austria and the North-German Empire, that have been settled and cultivated for upward of a thousand years. The northern borders of Ohio are kept comparatively fertile by the neighborhood of the great lakes, but the central regions, and many of the river-counties, begin to suffer from drought, and see their springs fail in every summer. The "Blue-Grass" region of Kentucky, once the pride of the West, has now districts of such a barren and arid nature that their stock-farmers are moving toward the Cumberland Mountains, because the creeks and old springs dried up, and their wells became too low to furnish water for their cattle.

Wherever tobacco and cotton are cultivated, the work of ruin has made rapid advances, and in all the southeastern counties of Virginia and North Carolina, and throughout Mississippi, Alabama, Georgia, and South Carolina, the traveler may ride for hours without seeing more than four or five trees in a group; droughts are becoming more and more frequent, and the locust, that ominous pioneer of the desert, has made its appearance.

The climatic influence of arboreal vegetation must be more generally understood, before such legislative measures as the importance of the subject demands, can be hoped for. In the economy of Nature forests perform innumerable functions which no artificial contrivance can imitate, and of which the following are only the most important:

Woods, in the first place, are the water-reservoirs of Nature, and hold in the network of their roots and their moss-carpet the moisture which is intended to supply our water-courses in the season of midsummer heat. One acre of full-grown beech-trees absorbs and dispenses as much humidity as twenty acres of grape-vines and tobacco, and more than two hundred acres of cereals.