NOTES ON CONTINENTAL FORESTRY. 175 



the dominating trees and partly among the domin- 

 ated. 



5. The total crop-increment depends, however, not only on 



the individual poles or trees, but also on the soil, the 

 condition of which can be greatly affected by the 

 way thinnings are made, — because artificial improve- 

 ments, such as soil-preparation and manuring, can 

 only be undertaken in exceptional cases. 



6. Next to a certain necessary degree of warmth, freshness 



or moisture in the soil is the main essential for 

 inducing rapid decomposition of the dead foliage 

 littering the ground, and rapid /iu//ii/s-iorma.tion is 

 always beneficial. 



7. J^ii mus-f OTma.tion is assisted by whatever measures can 



protect the soil against dry winds and direct insolation, 

 while allowing as free a passage as possible for the 

 atmospheric precipitations. 



(b) Practical Measures based on the above General Frwclples — 



1. As the thinning is generally made with a view to 



improve the growth of the crop, it should, particularly 

 in woods about 40 to 50 years old, give greatest 

 consideration to the dominating trees, rather than 

 to those more or less dominated. 



2. Hence, in young crops the aim will chiefly be to free 



all well-grown, dominating poles of valuable kinds 

 of trees from the pressure of their neighbours, and 

 especially from those of the latter that are badly 

 grown ; and when necessary, at the same time more 

 or less dominated trees of the better kinds should 

 be freed with a view to promote them into the 

 dominant class. Sickly, moribund, and dead poles 

 should, however, always be thinned out, but other- 

 wise suppressed stems that are still healthy should 

 only be removed when this is necessary to allow the 

 atmospheric precipitations to reach the ground in 

 sufficient quantity. 



3. Later on, when the crop has completed its main growth 



in height, the main object is to increase the leaf-area 

 by gradually allowing a larger growing-space to the 



