52 THE NEW FORESTRY. 



temperature and moisture than is found in open woods or 

 where the ground is exposed ; third, that density, or crowding, 

 causes the struggle for existence to set in . early, in which 

 struggle the trees begin to shed their lower branches while 

 they are. still young, grow in the desired cylindrical shape in 

 their stems, are free from knots, and produce timber of the 

 best quality for all purposes ; lastly, that the quantity of timber 

 produced to the acre is greater than can be produced by any 

 other system, and the value of the crop proportionately greater. 

 (See Chapter XII.) 



In practice, the Germans often plant several young trees 

 in one hole, the holes being from two to four feet apart, 

 according to the situation and soil poor and exposed situa- 

 tions receiving the most plants, and vice versa. Frequent and 

 severe thinnings are avoided as unmitigated evils, and so is 

 the admission of light and currents of air below the overhead 

 canopy ; shelter to the stems of the trees from both being of 

 the utmost consequence. The trunk of a tree in a dense 

 forest is regarded as but the channel between the soil and 

 living branches high up at the top of the tree, where growth 

 and elaboration is carried on. In the tended forests of 

 Germany, thinning is seldom attempted before the trees are 

 from twenty to thirty years of age, in the case of firs, while 

 hard woods, like the beech, coming up naturally in dense 

 masses, are often left unthinned for thirty-five or forty years. 

 ' When thinning is done, the greatest care is taken to preserve 

 the overhead canopy, and exclude air currents and winds, 

 even dead trees being often left standing if their removal is 

 going to create a gap. Crowding at all stages is the rule, 

 the live top of branches decreasing in proportion as the trees 

 grow older, until, at the end of the rotation period, in the case 

 of the spruce, only about one-sixth, or even less, of the entire 

 length of the tree will be furnished with branches, forming 

 just a tuft at the top, the trunk by this time having long shed 

 its lower branches, and formed a clean straight pole with very 

 little taper from end to end. In the case of hard wood the 

 proportion of top is much the same, a mere wisp, comparatively, 

 carrying on all the functions of growth successfully to the end. 

 However small the top of live branches may be, within reason- 

 able limits, it is sufficient to add a layer of timber to the trunk 

 annually, and given the required number of years, a tree of the 

 required dimensions is produced. Big trees of mature timber 

 are not so much sought after in Germany as trees of moderate 

 girth and of good useful quality. A crop of pit-props, for 



