In the Baltic Provinces of Russia it is common as coppice treated with a short revolution ; and often takes possession of forests, when the larger trees have been cut away, and succeeds in doing so, as it is able to grow very well on dry soil. In Germany and Austria it grows chiefly on the banks of streams and rivers, but is also met with on hilly ground and on mountain precipices. It is very rarely met with on peat-bogs. In the Alps it is especially common on gravelly soil, and it is the most common species in many places, where the mountain torrents form vast areas of gravel and sand, through which their branches spread in all directions. One of the most remarkable and beautiful of these woods is situated at 2500 feet elevation on the river Romanche near Bourg d’Oisans in Isére. The whole area is about 200 acres, one-half of which is composed of a dense wood of grey alder, mixed with a small number of aspens and ashes, the other half being more open and consisting of a mixture of grey alder and white willow. The dense wood is treated as coppice, with a revolution of thirty years, forty standards per acre being reserved each time of felling. When cut, the grey alder produces vigorous shoots, which grow rapidly till they are thirty-five or forty years old; after which time growth ceases and the shoots begin to die. At Bourg d’Oisans natural seedlings are very numerous.
The grey alder, unlike the common alder, suckers freely from the root, often at a great distance from the parent stem. It layers easily, and can also be propagated by cuttings. This facility of reproduction renders it of great service for the re-afforestation of the mountains in France, especially in the difficult work of planting trees on the sides of the torrents, where the soil is easily washed away.
Alnus incana is not a native of the British Isles, and has not yet been discovered in the fossil state there. (A.H.)
Cultivation
Though the tree is hardly known to English foresters, I believe that it may become an exceedingly useful one on account of its extreme hardiness, rapidity of growth and ability to thrive in very cold heavy soil, and in places subject to late and early frosts. I have used it with great success as a nurse to trees like Thuya plicata, in situations which were too wet and cold for that tree when young, and believe that it might be economically used for quickly suppressing rank herbage which would smother more tender and slower-growing trees in low and damp situations. It can be procured quite cheaply from French nurseries as one- or two-year seedlings, and grows with extraordinary rapidity on any soil, providing a dense cover, and rendering the land fit for planting. It soon overtops other trees, and if left standing requires the branches to be lopped so as to allow their heads to get up. It seems to thrive equally well on wet ground, and to grow much better than the common alder on soil too dry for that tree. I believe that the wood is at least as good, and according to Mouillefert is less brittle, than that of the common alder.
Though Loudon says that it was introduced as long ago as 1780, I have never seen a tree of any size in England; but Sir Hugh Beevor has sent me a photo- graph of one at Hargham in Norfolk, which measures about 72 feet high by 3 feet
