204 TENDINTt of crowded woods after EARF.Y YOT'TII. 



(lomiiiating trees ; so tliat the suppressed and dominated trees 

 are only rntainod so loii^' iis tliey arc reqnirod for the protection 

 of the soil. 



i. <'o.M.Mi:Nii;MKNr of TniNNi.N«;s. 



The first thinning; should l)e made as soon as the strnfrpjle 

 for existence has commenced, tliat is to say, wlien there is no 

 lonnrer sufficient space for the proper development of all trees. 

 Such early thinnings are to the interest of tlie dominating 

 trees, which thus are enal)led to lay on an extra (inantity of 

 ^YOod. and to acquire a greater power of resistance against 

 snow, rime and wind. In practice they are sometimes 

 dehu'ed, hecause their execution involves expenditure which 

 may not he covered h_y the receipts from the sale of the 

 thinned-oiit material. The financial loss thus incurred, how- 

 ever, may he more apparent than real, as it is generally more 

 than covered by the favoura])le development of the remaining 

 trees. 



ii. Dk.GKKK of TlllNNINi;. 



A thinning is called : — 



"Light," when o)ily dry and suppressed trees are removed; 



" Moderate," when, in addition, the whole or part of the 

 dominated trees is removed : 



" Heavy," when also a part of the dominating trees is cut; 

 in this case the suppressed trees may be left to give 

 shelter to the soil. 



In the present case, where quantity is the object, the 

 thinnings should on the whole be heavy, subject to the special 

 recpiirements of the species and the preservation of a sufficient 

 leaf canopy. As the demands on the growing space are very 

 great during the Ih-st half of life, thinnings must tlien be 

 comparatively heavier than later on ; heavier in the case of 

 light demanding and quick growing than in that of shade 

 bearing and slow growing species : heavier on good than on 

 poor soil. 



]\Iucli depends on the ori.^iiial density of the wood ; hence, 



