221 NATIRAL HKdKNEHATION (>F WOODS. 



primeval forest, if undisturbed, goes on regenerating itself for 

 generations. The process is a slow one, as the young crop 

 will only develop when sufficient light is admitted by the fall 

 or death of the old trees. In sylviculture it is accelerated by 

 the artilicial removal of a portion of the old trees, when they 

 have become lit for economic purposes. By degrees, modifi- 

 cations have been introduced, which lead to a number of 

 distinct methods. Of these, the following demand special 

 notice : — 



(1.) The Scleriiiiii Si/stciii.*— The age classes are evenly, or 

 approximately evenly, distributed over the whole area of the 

 forest. Throughout its entire extent the oldest, largest, and 

 diseased or defective trees are year after year, or periodically, 

 removed, followed b}^ the springing up of new growth in small 

 patches or single trees. 



(2.) The Group Si/steni. — The age classes are distributed over 

 the forest in groups of moderate extent. The oldest groups 

 are regenerated first, then the next oldest, and so on, until the 

 whole forest has been gone over. Some modifications of this 

 system have been introduced, which will be explained further on. 



(3.) The Compartment Si/stem.*^ — The age classes are so far 

 separated, that each occupies a distinct portion of the area, 

 representing an even aged, or approximately even aged, wood. 

 Each wood comprises one or moie compartments, and either 

 the whole, or one compartment at a time, is regenerated 

 uniforml}' over the area, so that tlie old crop is re})laced by a 

 young, fairly even aged wood. 



(4.) The Strip Si/strm. — This is a modification of the com- 

 partment system, each compartment being divided into a 

 number of strips. As it differs from the compartment system 

 in some respects, it will be dealt with separately, 



* The term selection syxtnn was intiodiicoil in India ; it is perhaps not an 

 ideal term, since a certain amount of selection is practised in all systems; it 

 has been retained, as none better is at jirescnt available. The system is called 

 Frmrlbetrieb, or Pldnterhetrielj, in (Jcrman. and Jurdimige in French. 



f Sehlfif/ireiner Jietrieh in (icruian, and mithode jmv eouprx mcrots) vex in 

 French. 



