The White Pine in Europe

by H. Mayr

 

THE White Pine was among the very first American trees which came to Europe, being planted in the year 1705 by Lord Weymouth on his grounds in Chelsea. From that date, the tree has been cultivated in Europe under the name of Weymouth Pine; in some mountain districts of northern Bavaria, where it has become a real forest tree, it is called Strobe, after the Latin name Pinus strobus. After general cultivation as an ornamental tree in parks this Pine began to be used in the forests on account of its hardiness and rapid growth, and it is now not only scattered through most of the forests of Europe, but covers in Germany alone an area of some 300 acres in a dense, pure forest. Some of these are groves 120 years old, and they yield a large proportion of the seed demanded by the increasing cultivation of the tree in Europe.

The White Pine has proved so valuable as a forest tree that it has partly overcome the prejudices which every foreign tree has to fight against. The tree is perfectly hardy, is not injured by long and severe freezing in winter, nor by untimely frosts in spring or autumn, which sometimes do great harm to native trees in Europe. On account of the softness of the leaves and the bark, it is much damaged by the nibbling of deer, but it heals quickly and throws up a new leader.

The young plant can endure being partly shaded by other trees far better than any other Pine tree, and even seems to enjoy being closely surrounded, a quality that makes it valuable for filling up in young forests where the native trees, on account of their slow growth, could not be brought up at all.

The White Pine is not so easily broken by heavy snowfall as the Scotch Pine, on account of the greater elasticity of its wood. The great abundance of soft needles falling from it every year better fits it for improving a worn-out soil than any European Pine, therefore the tree has been tried with success as a nurse for the ground in forest plantations of Oak, when the latter begin to be thinned out by nature, and grass is growing underneath them.

And finally, all observations agree that the White Pine is a faster growing tree than any native Conifer in Europe, except, perhaps, the Larch. The exact facts about that point, taken from investigations on good soil in various parts of Germany, are as follows:

  Years. Height. Annual Growth During Last Decade.
The White Pine at 20 reaches 7.5 meters. 37 centimeters
                “ 30      “ 12.5    “ 50        “
                “ 40      “ 18.5    “ 60        “
                “ 50      “ 22.5    “ 40        “
                “ 60      “ 26.5    “ 40        “
                “ 70      “ 28.5    “ 20        “
                “ 80      “ 30.0    “ 15        “
                “ 90      “ 32.0    “ 20        “

For comparison I add here the average growth on good soil, of the Scotch Pine, one of the most valuable and widely distributed timber trees of Europe.

  Years. Height. Annual Growth During Last Decade.
The Scotch Pine at   20 reaches 7.3 meters. 36.5 centimeters
                “   30      “ 11.6    “ 43.0        “
                “   40      “ 15.7    “ 41.0        “
                “   50      “ 19.4    “ 37.0        “
                “   60      “ 22.1    “ 27.0        “
                “   70      “ 24.0    “ 22.0        “
                “   80      “ 26.0    “ 17.0        “
                “   90      “ 27.5    “ 15.0        “
                “ 100      “ 28.5    “ 10.0        “
                “ 120      “ 30.0    “   7.5        “

That is, the White Pine is ahead of its relative during its entire life and attains at 80 years a height which the Scotch Pine only reaches in 120 years. It appears then that the whole volume of wood formed within a certain period by an acre of White Pine forest is greater than that yielded by a forest of Scotch Pine within the same period.

As far as reliable researches show, a forest of White Pine when seventy years old gives an annual increment of 3 cords of wood per acre. On the same area a forest of Scotch Pine increases every year by 2.4 cords on the best soil, 2 cords on medium soil, and 1.5 cords on poor soil.

But notwithstanding the splendid qualities which distinguish the White Pine as a forest tree its wood has never been looked upon with favor in Europe. Many of those who are cultivating the White Pine for business seem to expect that they will raise a heavy and durable wood. These are the qualities prized in their own timber trees, and they seem to think that the White Pine must be so highly prized at home for the same qualities, when in fact it is the lightness and softness of the wood which are considered in America. It would seem also that some European planters believe that a Pine tree exists which will yield more and at the same time heavier wood than any other tree on the same area. It is a general rule that the amount of woody substance annually formed on the same soil does not vary in any great degree with the different kinds of trees. For instance, if we have good soil we may raise 2,200 lbs. per acre of woody substance every year, from almost any kind of timber tree. If we plant a tree forming a wood of low specific gravity, we get a large volume of wood, and this is the case with the White Pine. If we plant on the same ground an Oak tree, we will get small volume of wood, but the weight of the woody substance will be the same, that is, 2,200 pounds of absolutely dried wood per acre.

It is remarkable that there is hardly any difference in the specific gravity of the wood of the White Pine grown in Europe and in its native country. I collected in Central Wisconsin wood-sections of a tall tree and compared the specific gravity with the wood of a full-grown tree of White Pine from a Bavarian forest. The average specific gravity of the Bavarian tree was 38.3. The average specific gravity of the American tree was 38.9. In both trees the specific gravity slightly increased from the base to the top. Professor Sargent gives 38 as the result of his numerous and careful investigations.

I was much surprised that the thickness of the sap-wood varied much in favor of the Bavarian tree.

The sap-wood measured in thickness:

  Of the Bavarian tree. Of the American tree.
At the base 2.7 centimeters 9 centimeters.
In the middle   .4         “ 6         “
Within the crown   .3         “ 4         “

I am inclined to believe that on account of the generally drier climate of America a greater amount of water, and, therefore, of water-conducting sap-wood, is necessary to keep the balance between the evaporation and transportation of the water. The wood of the White Pine is certainly better fitted for many purposes than any tree with which nature has provided Europe, and yet one can hardly expect it to easily overcome fixed habits and prejudices. It will devolve upon the more intelligent proprietors of wood-land in Europe to begin with the plantation of the White Pine on a large scale. No Conifer in Europe can be cultivated with so little care and risk as the White Pine; the frost does not injure the young plant, and the numerous insects invading the European trees during their whole life-time inflict but little harm. Subterranean parasites are thinning out the plantations to some extent, but in no dangerous way.

H. Mayr.

Tokio, Japan.