~14 THK NORMAL AGP] CLASSES. 



r5 + r„ + ( 



r 



Total = 1,000 acres. 

 Or again, if regeiiei-atioii extends over a still longer period :— 



C-s=-^X II = 200 acres. 



;• 



C4=— X II = 200 „ 



r 



C5 + C. + Ti + C2 =^{r - 2 X //) = 600 „ 



Total = 1,000 acres. 



c. Coppice Woods. 



As the rotation of coppice woods is short, it is usually 



possible to mark the annual coupes on the ground, so that 



grouping in age classes is not necessary. If the latter should, 



nevertheless, be considered desirable, generally not more than 



live gradations are thrown together, so that t'l comprises the 



1- to 5-years-old gradations, (.'2 those from 6 to 10 years, etc. 



Example : — 



Area = 200 acres. 



r = 20 years. 



II = 5 ,, 



The arrangement of age classes would be normal, if — 



C'i=-^X 5 = 50 acres. 



C.=^X^= 50 „ 



Total = 200 acres. 



