132 FOREST RICGUI.A'l'ION 



school can do little more than give a few principles, to guide in the 

 work. It needs study of the forest, and years of observation and 

 experience with species and site. For this reason the subject is dealt 

 with briefly in the textbooks on Regulation, is almost lost sight of 

 in some of them, in spite of the fact that it is just in this phase of 

 the work where knowledge, experience and capacity are most 

 needed. 



3. Regulation for Regularity in Age Classes as stated above, 

 works for sustained yearly cut of about equal amount and value, for 

 best growth possible under given conditions of Site, Species, Silvi- 

 culture and Rotation, and for a Growing Stock or amount of grow- 

 ing timber on the land, no greater than is necessary to secure growth 

 and income. It prevents Overcut and Undercut. 



It is particularly at this last point, the prevention of Overcut and 

 Undercut that this Regulation begins on new or wild woods property 

 because the first question asked, when there is once market for the 

 timber, is : how much can we cut on this property without over- 

 cutting ? 



4. From the nature of a forest property it is clear that there 

 are really only two way's of regulating the cut of timber : by Area 

 or by Volume. If a forester has a property of 20,000 acres and 

 works on a 100 year rotation, he can : 



a. Cut an Area of 200 acres per year and cover the propertv 

 every 100 years; or he can 



b. Cut an Amount or Volume of timber which he believes or 

 estimates to be equal to the amount which grows on his property, 

 say 15.000 cords. 



5. If faithfully persisted in and carefully revised every ten or 

 twenty years, and if Silviculture and Protection are attended to, 

 either of the two plans will regulate this forest. If he regulates by 

 Volume, he must begin somewhere and cut a sufficient area to get 

 the Volume estimated to be right, and he must do this year after 

 year, .\fter going over the property once or twice, he will almost 

 certainly drift into a method, cutting over each year the area he cut 

 during one year on his former round ; in other words, a Regulation 

 by \'olume is practically certain to change into a Regulation by 

 Area, which as Cotta correctly foresaw, over a century ago, is the 

 final in all Forest Regulation. 



