132 THE THEORY AND PRACTICE OF WORKING PLANS 



map either by color, or shading, or symbol. The kind of cutting 

 intended, e.g., shelterwood, can also be indicated by using the 

 symbols given in the " General Stand Table," Chapter I, 

 Section 2, above. 



Cutting Series 



When one cutting area is purposely joined to another and 

 this to a third, etc., they form a cutting series. In its perfect 

 form it is a silvicultural unit, usually consisting of several 

 compartments, in which the age classes are arranged so that 

 they form a complete series, thereby permitting each cutting 

 series to be handled independently. The object is to interrupt 

 the regular sequence of the age classes and thereby to interrupt 

 the continuity of cutting areas. This tends to reduce the 

 damage due to windfall and insects. (See frontispiece for 

 illustration.) Cutting series always progress from some initial 

 " point of attack " against the prevailing wind direction. They 

 are shown on the map by arrows. The formation of cutting 

 series is a tremendous safeguard against windfall, especially 

 where at the point of attack a wind-mantle has formed on the 

 edge of the stand to leeward. This mantle consists of the per- 

 sisting middle and lower branches of the trees on the edge of the 

 stand. It is artificially stimulated during the youth of the 

 stand by the cutting through of compartment lines, or forms 

 naturally along a road, stream, or other topographic inter- 

 ruption. It can also be created by heavy thinning along the 

 edge of a stand or compartment whereby the crowns remain 

 deep and hence the trees windfirm*. 



Cutting series can seldom be arranged without some minor 

 sacrifices. For example, in Fig. i the small, forty-eight-year 

 old stand ^d lies in the midst of the nearly merchantable seventy- 

 two-year old stand ye: 7^ would be sacrificed to the cutting 

 series, the lesser good to the greater. Only if the borders of 7J 

 had been liberated so as to form a mantle, could it be left after 

 7e has been cut. This would be done in the case of 7/, since 

 it is a much younger stand. 



