VAIAJK Of THINNINGS 



47 



In oak and pine thinning out of a large volume is necessary, in 

 spruce and beech it is not necessary but it is possible and desirable. 

 The smdfcer value of thinnings is due to inferior quality, is most 

 conspicuous in spruce and least in beech where even the final cut is 

 largely firewood. The tendency at present is for heavier thinnings 

 and a larger return from this source. In pine (Schwappach, p. 5) 

 the thinnings in 1889 made about thirty-five per cent of the total 

 growth while in 1908 they made about fifty per cent and the same 

 change is apparent in the treatment of other species. 



The influence of site on thinnings is ilustrated in the following 

 figures for the stand of pine one hundred and twenty years old : 



From the foregoing figures it is apparent that site greatly af- 

 fects the volume and value of thinnings and also that the difference 

 for different sites corresponds closely to that of the final stand. 



b. The influence of the method of treatment or silviculture 

 extends beyond the mere practice of thinning itself. A dense repro- 

 duction like good stands of natural reproduction, or dense seeding 

 and planting, call for early thinning. In many localities even in 

 central Europe such a thinning is made at a loss. Thinnings of oak 

 ten years old from usual seeding, also thinnings of beech and even 

 pine and spruce, come under this description. Here the method, if 

 artificial, by wider spacing may save money in seeds and plants and 

 again save the expense of early thinnings, besides producing larger 

 material in the same period of time. 



The mixed forest, especially mixture of hardwoods and con- 

 ifers, introduces disadvantages as well as advantages, with the for- 

 mer still prevailing. Thinnings of mixed stands require more judg- 

 ment and care and generally increase the difficulty of selling the 

 material. In hardwoods, like ash, hickory, maple, where small sec- 

 ond growth stuff is valuable the mixture may prove an advantage. 

 As stated before, the greatest differences in the income from thin- 

 nings rest with the thinning practice itself. Fifty and more years 



