GERMAN FORESr MANAGEMENT — SILVICULTURE. 



253 



Since it is observed that in the stiuggle for existence among the individual trees there are 

 quite early some trees getting the advantage and becoming dominant, it is inferred that thinnings 

 are most effective in the earlier period of the crop. 



In discussing the degree to which the thinning is to be made, a classification of the trees 

 according to the character of their development is made by German foresters as follows: 



Dominant or superior growth. < 



Dominated or inferior giowth. 



" Class 1. — Predominant trees with highly developed crowns 

 Class £*— Codommant tiees with tolerably well developed ciowns. 

 Class 8.— Subdommant trees with noinial crowns, but poorly developed and crowded 

 above. 



' Class 4. — Dominated tiees with crowns poorly developed and eiowded laterally. 



(a) Ciowns wedged m lateially, yet not overtopped 



(b) Crowns compressed, paitly overtopped. 

 Class 5. — Suppressed trees, entirely overtopped. 



(a) Crowns still having vitality (shade enduring species* ) 

 . (&) Crowns dying or dead. 



The following illustration of the appearance of these tree classes will be found serviceable in 

 understanding these relations. 



4 5 



13 20 



ri(x 26— Iicoclisses Classification accoidmg to crown development. Schematic Class 1 (pi edommant) Nos 1, 3, b, 11,16,20, class 

 2 (codommant) Nos 8 13, 18, class 3 (subdommant) Nos 9, 14, 17, class 4 (oppressed) Nos 5, 7, 12, class 5 (suppressed, a) Nos 2, 19, clasb 

 5 (suppressed, b) .Nos 4, 10, 15 



The degrees of thintfing usually resorted to are the following : 



(1) Slight thinning takes out trees of class 5. 



(2) Moderate thinning takes out trees of class 5 and 4&. 



(3) Severe thinning takes out trees of class 5, 4, and sometimes 3. 



The time when the first thinning should takeplace is generally determined by the possibility 

 of marketing the extracted material at a price 1 which will cover at least the expense of the 

 operation. This is, however, not always possible, and the consideration of the increase in value 

 of the remaining growth, or rather of the detriment to the same by omission of timely thinning, 

 may then be conclusive. 



On good soil and on mild exposures interlucation may take place earliest, because here the 

 growth is rankest and a difference in the development of the different stems is soonest noticeable. 



