JUDEICH'S METHOD. 337 



plan period, the probable amount of material to be taken out. 

 In doing this, the forester is guided by sylvicultural considera- 

 tions, and the degree of ripeness of the several standards. 



The sum total of the quantity of overwood thus ascertained, 

 and of the underwood, makes up the expected yield during the 

 working plan period. The executive officer should, however, 

 not be forced to abide absolutely by that estimate, but be per- 

 mitted to modify it within certain limits in accordance with 

 requirements, as they may become manifest in the course of 

 the period for which the working plan is drawn up. 



Intermediate cuttings occur on the areas not put down for 

 final cuttings. Their amount should be estimated in a 

 summary way on the basis of local experience. 



c. The Selection Forest. 



The selection forest resembles the coppice with standard 

 forest, since the several age classes are mixed on the area in 

 a similar manner. In the case of selection forests it is desir- 

 able to go round the whole area within a moderate number of 

 years, that is to say, to select again trees for felling over the 

 same portion of the area after a moderate interval, thus avoid- 

 ing having to cut too much at one time. 



The area to be taken in hand annually is obtained by divid- 

 ing the total area by the number of years, I, fixed as above. 

 By multiplying the quotient by 10, the area to be dealt 

 with during the next ten years is obtained. On the area thus- 

 fixed all mature trees are cut, and the necessary thinnings in 

 the younger age classes made. The age of maturity, or the 

 rotation, is fixed as in the case of clear cutting in high forest 

 cr the shelter-wood compartment system. 



Example : 



Area of a selection forest = 600 acres, 

 Botation = 120 years, 

 I = 20 years, 



600 

 Annual cutting area = =30 acres. 



