334 NATURAL REGENERATION BY SEED. 



narrow-crowaeJ as to require mtich encouragement to become 

 prolific seed-bearers ; hence there preparatory fellings may, and 

 often must, be made comparatively late. On cool or moist aspects, 

 in temperate climates, under clouded skies, &c,, on the other 

 hand, the earlier these fellings are undertaken, the better. 



(iv) The actual condition of the crop, i. e., its density and the 

 age, height, soundness, vigour and shape of the component trees. 

 The denser the crop, the younger or lankier or weaker or more 

 unhealthy the trees, the earlier must preparation for regeneration 

 commence. So also in an old crop, in which the trees have already 

 begun to contract their crowns, there is no room for delay. 



The preceding considerati ons being borne in mind, the prepara- 

 tory fellings must not, as a rule, be taken in hand until the stems 

 of the principal species have nearly attained exploitable dimensions ; 

 and they must give the future parent trees sufficient time to spread 

 out their crowns and come into full bearing by the time the seed- 

 felHng falls due. The first one will thus precede this felling by an 

 interval which may vary from 2 to 20 or even 30 years, but the 

 more usual period will be from 10 to 15 years. 



IV. What to remove in the preparatory fellings. 



The main point to bear in mind is never completely to isolate 

 the trees, but to make numerous gaps in the leaf-canopy, larger 

 or smaller according to the prevaihng conditions of growth, but 

 always small enough to enable them to close up within a few years, 

 before the soil can suffer from exposure. In making these gaps it 

 is neither the oldest nor the youngest, nor yet the wealiest or the 

 most vigorous that should be removed, but those which differ most 

 from the predominant age or size-class. We must endeavour to 

 produce a crop composed of trees of more or less one and the same 

 age, size and vigour, and as many of which as possible shall come 

 into full bearing when the seed-felling falls due. As regards 

 species, all undesirable ones should be got rid of or reduced to the 

 minimum compatible with the required fulness of the leaf-canopy. 

 After leaving enough seedbearers of each of the better kinds to 

 reproduce their species in sufficient abundance in the new crop, 

 the surplus should consist of promising individuals of those most in 

 demand. 



Hence in making the preparatory fellings, the following princi- 

 ples should be observed : — 



(i) Wherever a gap already exists, nothing, as a rule, should 

 be felled. 



