vi] METHODS OF TREATMENT 43 



strip usually placed at right angles to the direction of the wind, 

 which is generally the controlling factor of the climate in the 

 regions where this method is practised. The idea is to get side 

 protection against wind, drought, frost and sun, combined with 

 overhead light. 



The forest is divided up into periodic blocks in the ordinary 

 way, and a period of twenty or thirty years allotted for the 

 regeneration of each block. The fellings, which consist of suc- 

 cessive strips on which seed, secondary and find fellings, follow 

 one another in due succession at intervals of a few years, always 

 march against the wind, so that the young regeneration is 

 sheltered by an old crop. If the wind conditions are severe, 

 severance fellings must be made in advance to protect the lee- 

 ward crops from being damaged by exposure to the wind. 



This method is necessarily a rather rigid one, and in order to 

 regulate the rate of progress of the regeneration to fit the period 

 allotted, it will usually be convenient to institute a number of 

 cutting-series, and at the same time to vary the width of the 

 annual strip felled over. By a combination of these two expedi- 

 ents, the rate of progress of the regeneration can be controlled. 

 It may, however, be often found necessary, in all probability, 

 to supplement the natural regeneration by artificial re-stocking. 



42. The Group method. 



The group method is intermediate between the Uniform and 

 the Selection methods, but is generally included among the 

 methods applied to crops of mixed ages. It hardly forms a 

 separate method of treatment, but is rather a silvicultural 

 variation which may be applied either to the Selection method 

 in crops of mixed ages (Group-Selection), or to the Uniform 

 method in even-aged crops. In the latter case, the young 

 crops resulting from this kind of regeneration felling will be 

 less even-aged than those created under the Uniform method by 

 compartments or by strips, and may contain groups of young 

 growth varying by thirty years in age. This results from the 

 fact that the regeneration area is generally larger than in the 

 ordinary Uniform method, and the regeneration period con- 

 siderably longer. The organisation of the working-circle, and the 



