184 THE THEORY AND PRACTICE OF WORKING PLANS 



be topographic features or roads, trails, etc. Where these do 

 not suffice, lines are cleared to a width of 1-2 metres (3.28 to 

 6.56 feet) and rings of white paint put on the border trees. 



In uneven-aged stands the average age as well as the age 

 limits is to be given. Throughout the greatest attention is 

 given to the presentation of the age classes in their relation to 

 area by i, species, singly and in mixture; 2, site quahties; and 

 3, density of stocking. These are shown graphically by means of 

 diagrams. The reason of this attention to the age-class distri- 

 bution is that in even-aged high forest it is made, in conjunction 

 with data on the thriftiness of stands and their suitability to the 

 chosen site, the basis of regulating the cut and of judging the 

 progress towards a normal forest. In coppice with preponder- 

 ating standards (" Oberholzreicher IMittelwald ") and in selec- 

 tion forest a presentation of the age classes is seldom practi- 

 cable ; the most that could be done would be a summary of the 

 area occupied by each age class within the same (uneven-aged) 

 stand, and this gives no adequate basis for judgment. 



Detailed estimates are confined usually to those stands 

 intended for cutting during the ensuing working period of ten 

 years. Ocular estimates suffice if conditions are regular and 

 there are available data on cuttings of, or }ield tables for, 

 similar stands. In all other cases caliper measurements either 

 of sample plots or of every tree, as the irregularlity of the stand 

 may necessitate, are required. 



The increment is to be determined for the next twenty years, 

 because it is a fundamental principle that, at the end of twenty 

 years at the latest, the w^orking plan is to be completely revised, 

 growing stock, increment, and allowed cut redetermined. How- 

 ever, only half the increment for the twenty years is to be added 

 to the present volume of the stands to be cut, since at the end 

 of the first decade half of the stands so designated will have 

 been cut and be without further increment. 



The increment is taken either from suitable normal jdeld 

 tables or as the current annual. The former is simple; the 

 latter, in irregular and overmature stands, more reliable. The 



