X DEFINITIONS 



Increment is the increase, due to growth, in the volume of material 

 of a tree or crop, in a given time. 



Working-circle is an area of the forest worked under one and the 

 same method of treatment, with the same rotation, and the same set 

 of prescriptions under one and the same working-plan. 



Felling-series is an area of forest forming an entire working-circle, 

 or else a section of a working-circle, containing a complete separate 

 series of age-classes, thereby forming a miniature forest, and a unit 

 of management complete in itself. 



Cutting-series is a subdivision of a felling-series comprising a 

 number of age-gradations dififering in age by a constant number of 

 years. The object is to break up the succession of coupes in order to 

 reduce the danger of injury from wind. Instead therefore of a single 

 succession of crops on the ground from one year old up to a hundred, 

 the first cutting-series would contain — if there were five of them — 

 crops aged i, 6, ii, and so on up to 96, the second cutting-series 

 2, 7, 12... up to 97, and so on. 



Felling-cycle is the time elapsiag between two successive principal 

 feUings in the same area, worked by the Selection method. 



Rotation is the time elapsing between the creation of a crop and 

 its removal; or in other words, the age at which the crop attains 

 exploitabiUty under the stated object of management. 



Thinning is a cultural operation which consists in removing from 

 out of a growing tree crop the stems becoming superfluous, so that, 

 while realising these latter, each tree left standing may have sufi&cient 

 space to attain that state of development which is required for it to 

 satisfy the objects of management. 



