Note 296 — Chapter III · (continued 3)

Natural forests are rarely, if ever, composed of trees of a single species, and experience has shown that oaks and other broad-leaved trees, planted as artificial woods, require to be mixed, or associated with others of different habits.

In the forest of Fontainebleau, "oaks, mingled with beeches in due proportion," says Clavé, "may arrive at the age of five or six hundred years in full vigor, and attain dimensions which I have never seen surpassed; when, however, they are wholly unmixed with other trees, they begin to decay and die at the top, at the age of forty or fifty years, like men, old before their time, weary of the world, and longing only to quit it. This has been observed in most of the oak plantations of which I have spoken, and they have not been able to attain to full growth. When the vegetation was perceived to languish, they were cut, in the hope that this operation would restore their vigor, and that the new shoots would succeed better than the original trees; and, in fact, they seemed to be recovering for the first few years. But the shoots were soon attacked by the same decay, and the operation had to be renewed at shorter and shorter intervals, until at last it was found necessary to treat as coppices plantations originally designed for the full-growth system. Nor was this all: the soil, periodically bared by these cuttings, became impoverished, and less and less suited to the growth of the oak. * * * It was then proposed to introduce the pine and plant with it the vacancies and glades. * * * By this means, the forest was saved from the ruin which threatened it, and now more than 10,000 acres of pines, from fifteen to thirty years old, are disseminated at various points, sometimes intermixed with broad-leaved trees, sometimes forming groves by themselves."—Revue des Deux Mondes, Mai, 1863, pp. 153, 154.

The forests of Denmark, which, in modern times, have been succeeded by the beech—a species more inclined to be exclusive than any other broad-leaved tree—were composed of birches, oaks, firs, aspens, willows, hazel, and maple, the first three being the leading species. At present, the beech greatly predominates.—Vaupell, Bögens Indvandring, pp. 19, 20.