It is simply a method of preventing the wash of surface by rains, and at the same time of providing a substitute for irrigation of steep pasture-grounds, consisting in little more than in running horizontal furrows along the hillsides, thus converting the scarp of the hills into a succession of small terraces which, when once turfed over, are very permanent. Experience is said to have demonstrated that this simple process at least partially checks the too rapid flow of surface-water into the valleys, and, consequently, in a great measure obviates one of the most prominent causes of inundations, and that it suffices to retain the water of rains, of snows, and of small springs, long enough for the irrigation of the soil, thus increasing its product of herbage in a fivefold proportion. [Footnote: Troy, Etude sur le Reboisement des Montagnes, sections 6, 7, 21.]
As a further recommendation, it may be observed that this process is an admirable preparation of the ground for forest plantations, as young trees planted on the terraces would derive a useful protection from the form of the surface and the coating of turf, and would also find a soil moist enough to secure their growth.
Forests of Italy.
According to the most recent statistics, Italy has 17.64 per cent. of woodland, [Footnote: Siemoni, Manuale d'Arte Forestale, 2 ediz., Firenze, 1872, p. 542.] a proportion which, considering the character of climate and surface, the great amount of soil which is fit for no other purpose than the growth of trees, and the fact that much of the land classed as forest is either very imperfectly wooded, or covered with groves badly administered, and not in a state of progressive improvement, might advantageously be doubled. Taking Italy as a whole, we may say that she is eminently fitted by climate, soil, and superficial formation, to the growth of a varied and luxuriant arboreal vegetation, and that in the interests of self-protection, the promotion of forestal industry is among the first duties of her people. There are in Western Piedmont valleys where the felling of the woods has produced consequences geographically and economically as disastrous as in South-eastern France, and there are many other districts in the Alps and the Apennines where human improvidence has been almost equally destructive. Some of these regions must be abandoned to absolute desolation, and for others the opportunity of physical restoration is rapidly passing away. But there are still millions of square miles which might profitably be planted with forest-trees, and thousands of acres of parched and barren hillside, within sight of almost every Italian provincial capital, which might easily and shortly be reclothed with verdant woods. [Footnote: To one accustomed to the slow vegetation of less favored climes, the rapidity of growth in young plantations in Italy seems almost magical. The trees planted along the new drives and avenues in Florence have attained in three or four years a development which would require at least ten in our Northern States. This, it is true, is a special case, for the trees have been planted and tended with a skill and care which cannot be bestowed upon a forest; but the growth of trees little cared for is still very rapid in Italy. According to Toscanelli, Economia rurale nella Provincia di Pisa, p. 8, note—one of the most complete, curious, and instructive pictures of rural life which exists in any literature—the white poplar, Populus alba, attains in the valley of the Serchio a great height, with a mean diameter of two feet, in twenty years. Solmi states in his Miasma Palustre, p. 115, that the linden reaches a diameter of sixteen inches in the same period. The growth of foreign trees is sometimes extremely luxuriant in Italy. Two Atlas cedars, at the well-known villa of Careggi, near Florence, grown from seed sown in 1850, measure twenty inches in diameter, above the swell of the roots, with an estimated height of sixty feet.]
The denudation of the Central and Southern Apennines and of the Italian declivity of the Western Alps began at a period of unknown antiquity, but it does not seem to have been carried to a very dangerous length until the foreign conquests and extended commerce of Rome created a greatly increased demand for wood for the construction of ships and for military material. [Footnote: An interesting example of the collateral effects of the destruction of the forests in ancient Italy may be found in old Roman architecture. In the oldest brick constructions of Rome the bricks are very thin, very thoroughly burnt, and laid with a thick stratum of mortar between the courses. A few centuries later the bricks were thicker and less well burnt, and the layers of mortar were thinner. In the Imperial period the bricks were still thicker, generally soft-burnt, and with little mortar between the courses. This fact, I think, is due to the abundance and cheapness of fuel in earlier, and its growing scarceness and dearness in later, ages. When wood cost little, constructors could afford to burn their brick thoroughly, and to burn and use a great quantity of lime. As the price of fire-wood advanced, they were able to consume less fuel in brick- and lime-kilns, and the quality and quantity of brick and lime used in building were gradually reversed in proportion.
The multitude of geographical designations in Italy which indicate the former existence of forests show that even in the Middle Ages there were woods where no forest-trees are now to be found. There are hundreds of names of mediaeval towns derived from abete, acero, carpino, castagno, faggio, frassino, pino, quercia, and other names of trees.] The Eastern Alps, the Western Apennines, and the Maritime Alps retained their forests much later; but even here the want of wood, and the injury to the plains and the nagivation of the rivers by sediment brought down by the torrents, led to legislation for the protection of the forests, by the Republic of Venice, at various periods between the fifteenth and the nineteenth centuries, [Footnote: See A. de Bereuger's valuable Saggio Storico della Legislazione Veneta Forestale. Venezia, 1863.
We do not find in the Venetian forestal legislation much evidence that geographical arguments were taken into account by the lawgivers, who seem to have had an eye only to economical considerations.
According to Hummel, the desolation of the Karst, the high plateau lying north of Trieste, now one of the most parched and barren districts in Europe, is owing to the felling of the woods, centuries ago, to build the navies of Venice. "Where the miserable peasant of the Karst now sees nothing but bare rock swept and scoured by the raging Bora, the fury of this wind was once subdued by mighty firs, which Venice recklessly cut down to build her fleets."—Physische Geographie, p. 32.] by that of Genoa as early at least as the seventeenth; and both these Governments, as well as several others, passed laws requiring the proprietors of mountain-lands to replant the woods. These, however, seem to have been little observed, and it is generally true that the present condition of the forest in Italy is much less due to the want of wise legislation for its protection than to the laxity of the Governments in enforcing their laws.
It is very common in Italy to ascribe to the French occupation under the first Empire all the improvements and all the abuses of recent times, according to the political sympathies of the individual; and the French are often said to have prostrated every forest which has disappeared within this century. But, however this may be, no energetic system of repression or restoration was adopted by any of the Italian States after the downfall of the Empire, and the taxes on forest property in some of them were so burdensome that rural municipalities sometimes proposed to cede their common woods to the Government, without any other compensation than the remission of the taxes imposed on forest-lands. [Footnote: See the Politecnico for the month of May, 1862, p. 234.] Under such circumstances, woodlands would soon become disafforested, and where facilities of transportation and a good demand for timber have increased the inducements to fell it, as upon the borders of the Mediterranean, the destruction of the forest and all the evils which attend it have gone on at a seriously alarming rate.
Gallenga gives a striking account of the wanton destruction of the forests in Northern Italy within his personal recollection, [Footnote: "Far away in the darkest recesses of the mountains a kind of universal conspiracy seems to have been got up among these Alpine people,—a destructive mania to hew and sweep down everything that stands on roots."—Country Life in Piedmont, p. 134.