ch.viii REGENERATION BY SEED 203 



after leaving wind-belts on the ridges, the fellings should 

 first be made in the upper parts of the slopes, as, if 

 begun at the bottom, although regeneration would be 

 better encouraged, the young crop of seedlings would 

 run the danger in subsequent years of being injured 

 by the fellings made above them, and by the consequent 

 export works. 



The great advantage of this system, apart from its 

 simplicity, is that the fellings are concentrated and 

 compact, and that supervision is easier and the extrac- 

 tion of timber is much cheaper than when the fellings 

 are more scattered. 



On the other hand, success in regeneration is so 

 problematical or so irregular and long deferred that even 

 where a sale for the whole out-turn is obtainable, it is a 

 method which cannot usually be commended in tropical 

 forestry. I have never seen it employed by foresters in 

 the Tropics, but the effect of such an operation can be 

 studied in places where shifting cultivation has made 

 gaps in forest lands. Among these effects the following 

 may be quoted : 



The whole area got covered with a dense growth of 

 grass or bamboos which occupied the soil with its rhi- 

 zomes, e.g. by Imperata arundinacea and Ochlandra 

 stridula ; or the area was invaded by dense shrubs, 

 usually thorny, and by creepers, through which, after an 

 interval of many years, more arborescent growth began 

 to struggle ; or a poor growth of ferns and under-shrubs, 

 such as Gleichenia and Hedyotis, came up, and left the 

 soil unimproved and sterile as far as tree growth was 

 concerned ; or the soil remained bare, fissured, and hard 

 baked, and produced nothing but a few stunted shrubs 

 and under-shrubs. 



In a few cases a quick-growing mass of soft-wood ed 

 trees covered the area, such as Trema and Macaranga, 

 and under their shelter seedlings of more valuable species 

 sprang up. This was on good soil and with well dis- 

 tributed rainfall. 



The above examples are hardly sufficiently encourag- 



