A year among the trees

by Wilson Flagg

The Willow, though tenacious of life, will not prosper in dry places. Its presence is a sure indication of water, either on the surface of the ground or a little beneath it. The grass is green at all times under this tree, and the herds that browse upon its foliage and young branches find beneath them the most grateful pasture. In the New England States it has long been customary to plant Willows by the wayside, wherever the road passes over wet grounds. Some of the most delightful retreats of the pedestrian are found under their shady boughs. When he is panting with heat and thirst, the sight of their green rows fills him with new animation, as they indicate the presence of water as well as cooling shade. The same comely rows are seen skirting the pools and watercourses of our pastoral hills and arable meadows. They are planted also by the sides of streams and canals, where they serve, by their long and numerous roots, to consolidate the banks, and by their leaves and branches afford shelter to cattle. These Willows are among the fairest ornaments of the landscape in Massachusetts just after the elm and red maple have put forth their flowers. And so lively is their appearance, with their light green foliage, that when we meet with a group of them in the turn of a road on a cloudy day, we seem to be greeted with a sudden gleam of sunshine.

The Willow is one of the few trees which have been transplanted from Europe to our own soil without being either equalled or surpassed by some American tree of kindred species. But there is no indigenous Willow in any part of the American continent that will bear comparison in size and in those general qualities which we admire in trees, either with the Weeping Willow or the common yellow Willow. The latter is as frequent in our land as any one of our native trees, except in the forest. It attains a considerable height and great dimensions, seldom forming a single trunk, but sending upward from the ground, or from a very short bole, three or four diverging branches, so as to resemble an immense shrub. This mode of growth is caused perhaps by our way of planting it,—by inserting into the ground cuttings which have no leading shoot. Indeed, all these Willows are pollards. Not one of the species is found in our forest, except where it has spread over land that has once been cleared and cultivated. In that case, we find mixed with the forest trees Willows, apple-trees, and lilacs, which were planted there before the tract was restored to nature. I have seen trees of this species growing as standards of immense size, with their branches always joining the trunk very near the ground. On this account little rustic seats and arbors are more frequently erected in the crotch of a Willow than in that of any other tree.

The most of our indigenous Willows are mere shrubs. Though there are above thirty American species, but few of them rise to the stature of trees. Some of them are creeping plants and prostrate shrubs, some are neat and elegant trees in miniature. Their branches are also of many colors, some of a fine golden hue, spreading a sort of illumination over the swamps where they abound; some are red; others with foliage so dark as to have gained the name of Mourning Willow. Some, like our common bog Willow, are called white, from their downy or silken aments. One of the most beautiful of the small species is the golden osier, or Basket Willow. The yellow twigs of this shrub, coming up from the ground like grass without subdivisions, but densely from one common root, are very ornamental to low grounds. It would seem as if Nature, who has given but little variety to the foliage of this tree had made up for its deficiency by causing the different species to display a charming variety in their size. Thus, while the common yellow Willow equals the oak in magnitude, there are many species which are miniature shrubs, not larger than a heath plant. As one of the beautiful gifts of nature, the Willow claims a large share of our admiration. Though not a convenient ornament of our enclosures, the absence of this tree from the banks of quiet streams and glassy waterfalls, overhanging rivers and shading the brink of fountains, would be most painfully felt by every lover of nature.

ROTATION AND DISTRIBUTION.

It has been observed by foresters that there is a tendency in any soil which has long been occupied by a certain kind of timber, to produce, after the trees have been felled, a very different kind, if it be left to its spontaneous action. The laws affecting such rotations have been very well ascertained, and a careful investigation of the subject would undoubtedly reveal many curious facts not yet known. If the stumps of the trees, consisting of oak, ash, maple, and some other deciduous kinds, remain after the wood is felled, they will throw up suckers, and the succeeding timber will be an inferior growth of the original wood. But if the stumps and roots of the trees should be entirely removed, it would be more difficult to determine what would be the character of the next spontaneous growth. It would probably be planted by the kinds that prevail in the neighboring forests, and it would depend on the character of the soil whether the hard or soft-wood trees would finally predominate.

There is an important chemical agency at work, that originally determines the distribution of forests, and afterwards their rotation. The hard-wood trees require more potash and a deeper soil than the coniferous and soft-wood trees. Hence they are found chiefly on alluvial plains and the lower slopes of mountains, where the soil is deep and abounds in all valuable ingredients for the support of vegetation. Pines and firs, on the contrary, though frequently discovered of an immense size on alluvial soils, are generally crowded out of such grounds by the superior vigor of the hard-wood trees; and they can only maintain their supremacy on barren and sandy levels, and the thin soils of mountain declivities, too meagre to support the growth of timber of superior kinds. But a wood must stand a great many years, several centuries perhaps, after its spontaneous restoration, before this order of nature could be fully established. We must observe the spontaneous growth and distribution of herbaceous plants in different soils to ascertain these laws, which are the same in a field as in a forest.

When any growth of hard wood has been felled and the whole removed from the ground, the soil, having been exhausted of its potash, cannot support a new and vigorous growth of the same kind of timber. The succession will consist of a meagre growth of the same species from seeds already planted there; but the white birch and poplar, especially the large American aspen, usually predominate in clearings in this part of the country. When a pine wood is felled, it is succeeded by an inferior growth of conifers, and a species of dwarf or scrub oak. Seldom, indeed, after any kind of wood has been cut down and carried away from the spot, can the exhausted soil support another that is not inferior in quality or species. Though an oak wood may be succeeded by pines, a pine wood will not be succeeded by oaks or any other hard timber, unless the trees were burned and their ashes restored to the soil. Hence we may account for the fact that poplars, white birches, and wild-cherry-trees, occupy a larger proportion of the ground that is now covered with wood than they did a century ago, in all parts of the country.

I have already alluded to the well-known fact, that the generic character of the timber, in the distribution of the primitive forest, in any country, is determined in great measure by the geological character of the soil. On sandy plains in the primitive forest, the white birch, the poplar, the aspen, and the pitch pine were abundant, as they are now on similar soils. The preference of the red maple for wet and miry soils is well known; while hard maple, oak, beech, and hickory do not prosper except in strong alluvial tracts. A heavy growth of hard timber indicates a superior soil; pine indicates an inferior one, if it has been left to the spontaneous action of nature. In the primitive forest we were sure of finding such relations of soil and species. They are not so invariable since the operations of agriculture have interrupted the true method of nature.

When a wood has been burned, the process of renewal, when left to nature, is much more tardy than if it had been felled, since it can now be restored only by a regular series of vegetable species, which must precede it, according to certain inevitable laws. The soil, however, being improved and fertilized by the ashes of the burnt timber, is in a chemical condition to support a luxuriant forest as soon as in the course of nature it can be planted there. Trees will not immediately come up from this burnt ground as in a clearing; and if they should appear, they would mostly perish from the want of protection. In the order of nature herbaceous plants are the first to occupy the soil, and these are followed by a uniform succession of different species. There is an epilobium, or willow herb, with elegant spikes of purple flowers, conspicuous in our meadows in August, which is one of the earliest occupants of burnt ground, hence called fireweed in Maine and Nova Scotia. The downy appendage to its seeds causes it to be planted there by the winds immediately after the burning. The trillium appears also in great abundance upon the blackened surface of the ground in all wet places. Plants like the ginseng, the erythronium, and the like, whose bulbs or tubers lie buried deep in the mould, escape destruction, and come up anew. These, along with several compound plants with downy seeds, and a few ferns and equisetums, are the first occupants of burnt lands.

But the plants mentioned above have no tendency to foster the growth of young trees. They are, however, succeeded by the thistles and thorny plants, which are nature’s preparation of any tract, once entirely stripped of vegetation, as a nursery for the seedlings. All the phenomena of nature’s rotation are but the necessary giving place of rapid-growing and short-lived plants to others which are perennial and more capable of maintaining their ground after being once planted. Thorns and thistles soon appear on burnt lands, and protect the young trees as they spring up, both from the winds and the browsing of animals. Thus many an oak has been nursed in a cradle of thorns and brambles, and many a lime-tree growing in a bower of eglantine has been protected by its thorns from the browsing of the goat.