116 Forestry Quarterly 



In youth, the ring ividth decreases and that rapidly from the 

 breast height to the top. Later, the same condition exists up to 

 a point which changes with age, beyond which the ring width 

 increases at first slowly, towards the crown at increasing rate. 

 In pine and oak, this first decrease of the ring width and diameter 

 in the lower part is most rapid and up to a highest point at 24 to 

 30 feet, less in beech and least in fir. Beyond this point of small- 

 est ring width, the increase in spruce, fir and pine is progressive 

 up to nearly the tip, so that the ring width is largest in the upper, 

 part, on the average 2 to 2.5 times the width at breast height. 



In beech and oak on the contrary, after the increase in the 

 middle part, in the crown and toward the top a rapid decrease 

 of diameter increment takes place, so that it may sink below that 

 of the increment at breast height. 



From the point at breast height down almost in all cases, and 

 especially in spruce, an increase of ring width is found, so that 

 at one foot from the ground, stump height, it is in spruce 20 to 

 40 per cent, in other species 10 to 20 per cent, larger than at 

 breast height. Only exceptionally, in the youngest age classes 

 the stump shows the same or even a smaller ring width. 



4. The cross section area increment decreases generally from 

 base to top, and that rapidly up to 10 or 16 feet, only little in 

 the middle part, and again more rapidly toward the top. In 

 the youngest age classes this decrease is rapid. Only in pine and 

 fir, and occasionally in spruce has an equal or even slightly in- 

 creasing area increment been observed in the middle portion 

 of the stem. 



5. The influence of site shows itself in that on poorer sites, 

 with smaller height development, the diameter increment (ring 

 width) increases more rapidly and the area increment decreases 

 more rapidly than on better sites. Also the increase is less on 

 the poorer sites of both increments than in the tall stems of the 

 better sites. 



6. Density, closer and opener stand, has an influence, at least 

 on spruce, in that the lower stem classes show a still greater in- 

 crease of ring width towards the top, up to 3 and 3.5 times that 

 at breast height than the better stem classes, and while in the 

 latter the area increment in the middle portion invariably de- 

 creases, in the lower stem classes it remains even or even in- 

 creases somewhat. The root collar is also more developed in 



