FOREST ECONOMY. 199 



hence, unless special provisions are made in the 

 management of a forest property, the crop and the 

 revenue would mature and be harvested periodically 

 only, and that in long periods ; from twenty to a 

 hundred years and more would elapse from the 

 sowing to the reaping. 



The farmer may be satisfied to practise on his 

 wood lot attached to his farming business what is 

 technically called an " intermittent " management, 

 harvesting and reproducing from time to time 

 without attempting to secure regular annual re- 

 turns. But when forestry is to be practised as an 

 independent industry, it becomes desirable, as in 

 any large mercantile establishment, to plan, organ- 

 ize, and manage the business so as to secure, 

 continuously and systematically, a regular annual 

 income nearly equal or increasing year by year. 



The lumberman or forest exploiter also plans 

 and organizes his business for annual returns, not, 

 however, to be derived continuously from the same 

 ground ; he seeks a new field, he changes his 

 location as soon as he has exhausted the accumu- 

 lated stores of his forest property, which he then 

 abandons or devotes to other purposes than wood- 

 cropping. 



The forester's business is based upon the con- 

 ception of what is technically called the "sus- 

 tained yield " (Ger. NachJialtigkeitsbetrieb, Fr. 

 Possibility), a continued systematic use of the 

 same property for wood -crops, the best and 



