Answers to Correspondents.
When the woods are cut clean in Southern New Hampshire White Pine comes in very, very thickly. Is it best to thin out the growth or allow the trees to crowd and shade the feebler ones slowly to death?
J. D. L.
It is better to thin such over-crowded seedlings early, if serviceable timber is wanted in the shortest time. The statement that close growth is needed to produce long, clean timber, needs some limitation. No plant can develop satisfactorily without sufficient light, air and feeding room. When trees are too thickly crowded the vigor of every one is impaired, and the process of establishing supremacy of individuals is prolonged, to the detriment even of those which are ultimately victorious. The length is drawn out disproportionately to the diameter, and all the trees remain weak.
Experience has proved that plantations where space is given for proper growth in their earlier years, yield more and better wood than do Nature’s dense sowings. Two records are added in confirmation of this statement, and many others could be given:
1. A pine plantation of twelve acres was made, one half by sowing, the other half by planting at proper distances. In twenty-four years the first section had yielded, including the material obtained in thinnings, 1,998 cubic feet, and the latter, 3,495 cubic feet of wood. The thinnings had been made, when appearing necessary, at ten, fifteen and eighteen years in the planted section, yielding altogether ten and three-quarter cords of round firewood and seven cords of brush; and at eight, ten and twenty years in the sowed section, with a yield of only three and one-fifth cords of round firewood at the last thinning and seven and four-fifths cords of brush wood.
2. A spruce growth seeded after thirty-three years was still so dense as to be impenetrable, with scarcely any increase, and the trees were covered with lichens. It was then thinned out when thirty-five, and again when forty-two years old. The appearance greatly improved, and the accretion in seven years after thinning showed 160 per cent. increase, or more than 26 per cent. every year.
The density of growth which will give the best results in all directions depends upon the kind of timber and soil conditions.
—B. E. Fernow.