ON THINNINGS IN PLANTED SPRUCE, 131 



sequently, early thinnings may be long deferred, and the later 

 ones made with great moderation, without endangering the 

 prosperity of such natural high forest. 



The case is diffei-ent with artificial spruce crops planted in a 

 single operation, in lines, triangles, quincunx, etc., on bare soil. 

 All these plants start together, and the struggle is between equals. 

 Here comes in a question which has never had, and can never 

 have, a general answer. It refers to the spacing of the plants. 

 Practice varies from 2 to 10 feet. In fact, the distance depends 

 on the object in view. Hop-poles to be cut clean at about twenty- 

 five years old, must be close grown, say 4000 per acre. For 

 paper pulp, or useful poles to be cut at about forty years old, 

 two-thirds of the number will suffice. For telegraph poles or 

 small carpentry, to be cut at sixty years, 2000 plants will be 

 about right. For sawyer's timber no more may be needful than 

 1 200 to 1 600 planted 5 or 6 feet apart, or better still if irregularly 

 spaced. 



It is true that widely spaced plants, sturdy from their youth up, 

 make strong and quick -growing trees. But for good useful timber 

 it is absolutely necessary that the lower branches must perish and 

 fall while still thin, leaving a trunk clear and free from knots. 

 Upward growth is the great point ; the crown pushing rapidly up 

 suffices amply for the prosperity of the tree when it occupies no 

 more than a fourth of the total height. Young growing spruce 

 must therefore be thinned with extreme moderation, and the 

 density must be kept as close as is consistent with good 

 growth. Thinnings in even-aged young spruce are certainly 

 more difficult, and more necessary, than in natural crops. The 

 principle to be adopted is, to free the tallest and reduce their 

 number without removing the weakest (unless their tops are dry), 

 since these latter ensure natural pruning, cover and protect the 

 soil, and add the strength of a close canopy. The spruce is truly 

 named excelsa. Not like the ash excelsior, "above my neigh- 

 bours," but simply excelsa, "ever upward." The fir, though often 

 taller than the spruce, ends by acquiring a flat, tabular top, whilst 

 the spruce points upwai'd to the last. 



In order that the spruce may have a sufficiently rapid growth, 

 as well as a clean bole, the crown must be allowed a duly propor- 

 tionate height, say, one-fourth of the total height of the tree. 

 This proportion can be assured by maintaining a suitable density 

 in the crowns. If the crop is to grow on to the age of sixty. 



