SEVERANCES. 



123 



take place 20 to 30 or more years hence, the then exposed 

 windward edge of the compartment to be protected will be 

 better able to resist the wind, and will also have the additional 

 protection of the younger strip planted along the severance.' j.; 



For example, a crop of 40 years old (Fig. 31) lies in the lee of a crop 

 60 years old, which will probably have to be felled about 20 years hence, 

 before the former is mature. For the protection of the 40 -year-old crop, 

 when the annual fall cuts into the mature crop (then 80 years old) 20 

 years hence, the former should immediately be strengthened by a severance 

 (a b) being made to a breadth of about a chain in the latter ; and this 

 cleared strip should be at once planted up. 



' ' J v . 



Most dangerous wind, 



W. 



Direction of annual 

 falls, 



<- E: to W. 



Severances should be made early enough to allow of the tryes 

 along the windward edge of the compartment needing protection 

 to strengthen themselves against wind by extending their root- 

 system outwards. If the trees are already so old that they 

 cannot do this to any extent, then making the severance is of 

 little or no use. Hence the. success of this measure depends 

 upon the kind and age of the crop, the soil and situation, &c. 

 But it is far more necessary for Conifer crops (and especially 

 Spruce) than for broad-leaved woods. 



Different methods of Fixing the Annual Fall. Where 

 only simple coppice or coppice with standards is concerned, 

 worked with a rotation of, say, 15 or 20 years, then the equal, 

 i.e., equally productive, areas forming the 15 or 20 annual falls 

 naturally range themselves into a simple felling-series from 1 to 

 15 or 20. And the same applies to the periodic block method 

 of regenerating beechwoods on the chalk -hills of Southern 



