332 NATUitAt, REGESEtlATlON BV SfiBlJ. 



(iii) On the climate and locality. The caution to be observed 

 ■will be in proportion to the extremeness of the climatic factors. 

 A very favourable (forcing), as v^ell as a very unfavourable climate 

 and locality, will require the fellings to follow each other at shoi'fc 

 intervals. 



(iv) On the actual density of the crop. The closer the trees 

 stand together, the more likely are they to be thin and lanky, 

 weak-rooted and wanting in vigour, and hence the necessity of 

 frequent light operations. 



(v) On the predominant age of the crop. The more advanced 

 the age of the majority of the trees beyond that of first fertility, 

 the greater, as a rule, will be the necessity of obtaining the desired 

 results in a limited time, and hence also for often repeating the 

 felling. 



(vi) On the condition of the crop. The more numerous damaged 

 or unsound trees are, the more frequently must the woodcutter be 

 admitted in order to utilise them quickly and favour the develop- 

 ment of the rest. 



(vii) On tlie necessity of obtaining the desired results as quickly 

 as possible. The crop to come under regeneration may be very 

 young and hence require special forcing to induce early and 

 abundant fertility. So also, if the position of the crop in the forest 

 necessitates its regeneration without delay. In either case, the 

 only possible mode of attaining the end sought, without risking 

 the safety of the crop, is to thin it out frequently, but each time 

 lightly. 



(viii) On the question whether a seed felling can be made every 

 year or'i only at intervals of several years. In the latter case, the 

 preparatory fellings will usually have to contribute, to an appreci- 

 able extent, towards making up the deficiency in the annual yield 

 during the interval between two seed fellings ; and hence, in order 

 to spread the produce of the preparatory coupes over as many indi- 

 vidual years as possible, the fellings should be light and come round 

 again frequently. 



To summarise what precedes, repetition of the fellings may aim 

 at. securing one or more of the following objects : — (1) forcing 

 early fertility, (2) preparation of weak trees for isolation, (3) 

 preventing strong weed growth from taking possession of the soil, 

 (4) timely utilisation of decaying trees when numerous, and (5) 

 supplementing insufficiency of outturn when several years elapse 

 between one seed felling and the next. 



In extreme cases a single preparatory felling may suffice, or 



