234 GOVERNMENT REGULATION AND WORKING PLANS 



Area and Age. — The regulation of (g) coppice-under-standards is 

 based on clear cutting the coppice and felling the ripe or deteriorating 

 standards (and thinning the IR standards where necessary) each time 

 the coppice is clear cut. Therefore the cutting cycle is equal to the 

 coppice rotation. The coppice cut is regulated by felling an equal area 

 each year (see (a) page 232); the standards are cut when they reach 

 maturity — say four coppice rotations — and sooner if they show signs 

 of disease. In addition some of the immature standards are also re- 

 moved at the time of the coppice felHng. An approximately equal 

 annual cut in standards is obtained, since an approximately equal 

 number of fresh standards are reserved when the coppice is cut. The 

 natural loss of standards while they are growing to maturity is fairly 

 uniform. Great freedom is allowed in leaving thrifty trees for added 

 growth and in removing those at a standstill. Occasionally the amount 

 of the cut in standards is gauged by applying an empirical growth per 

 cent to the growing stock represented by the overwood or standards 

 and then cutting just the amount of the growth. Since the standards 

 are selected and reserved from the coppice stand the number secured is 

 in theory fairly uniform and there is no danger in cutting on a growth 

 per cent basis unless the new supply of IR standards falls short (see 

 pp. 94-98). 



Method of 1883. — This method originated in France and will therefore 

 be discussed in considerable detail, especially as Schaeffer has developed 

 several refinements which have never been understood in the United 

 States, and since this method could be applied to selection forests of 

 spruce and fir in New England and elsewhere. This so-called method ^^ 

 of 1883 as applied to (h) selection forests of tolerant species is as follows: 



After the inventory, by diameter classes, determine the rotation and 

 the corresponding size of tree, then classify the stock in three classes: 



(1) Old wood, trees more than two-thirds the exploitable diameter; 



(2) average wood, less than two-thirds and more than one-third; (3) 

 young wood, less than one-third (usually not calipered). Where there 

 is a normal, or nearly normal, proportion of old and average wood the 

 cut ^^ equals the volume of the old wood divided by a third of the rotation 



33 Based on the original official instructions issued by the Secretary of Agriculture and 

 on the Chamonix Working Plan, by A. S. Schaeffer. 



34 The student should compare this method with the Hufnagl "diameter class method" 

 described by Recknagle, pp. 100-105. The Hufnagl method (Variation 1) is: "Annual 



cut = Volume of trees or of diameter classes - years and over, plus increment thereof 



• r „ 



m - years. . . . 



Recknagle gives an interesting example of (Variation 2) where the trees have been 

 grouped by 3-inch classes with the basis data (for each class) of volume per tree, average 

 number of trees per acre, and years required to grow from one class to the next (and 



