THE THEORY AND- PRACTICE OF WORKING PLANS 217 



slopes by a trail following the appropriate contour. This pro- 

 tection belt is always managed as strictest selection forest. 

 The management for the rest of the working unit is then decided 

 upon and the area divided into " Betriebsklassen " (working 

 groups), cutting series, compartments, and subcompartments. 



An area with a uniform silvicultural method and rotation, 

 uniform market and constituting a single logging unit is called 

 a Betriehsklasse; it is further divided into cutting series, whose 

 formation depends on the topography, the species, and the 

 method of reproduction. A single cutting series does not usually 

 comprise more than three compartments. The boundaries of 

 the cutting series are topographical or artificial — roads, com- 

 partment lines, etc. These boundaries are to be cleared of tim- 

 ber to a width of from i6 to 26 feet, in order that a wind-resist- 

 ing mantle may form along the edges of the stands. Cutting 

 series are shown on the maps by arrows. 



The compartments (Abtcilungen) are units of convenience; 

 their shape is quadrangular, 2600 to 3300 feet long and about 

 two-thirds as wide. The boundary lines are topographic, 

 cultural (roads, railroads, etc.), or else artificial. The last are 

 either " Schneisen " and are usually made 6| feet wide ii 

 metres), or are " Wirtschafts Streifen," with the regular width 

 of 16 to 26 feet (5-8 metres). 



The division into subcompartments (Unterabteilungen) is 

 based (i) on differences in required treatment of which the fol- 

 lowing are distinguished: High forest with clear cutting; high 

 forest with shelterwood cutting; high forest with selection cut- 

 ting; simple coppice; coppice with standards; forest burdened 

 with servitudes; protection forest, voluntary or enforced by 

 law: or (2) on difi'erences in species if the stands are pure: 

 or (3) on substantial differences in percentage of mixture if 

 the stands are mixed: or (4) on differences in average age, ex- 

 ceeding ten years in young, twenty years in old high forest, 

 five years in coppice forest: or (5) on marked differences in 

 site quality or stand quality as shown by substantial differences 

 in the height growth of equal-aged stands: or (6) on marked 



