2 GENERAL CONSIDERATIONS 



First, silviculture as yet has been practiced to a limited 

 extent and during a period of only a few years in North 

 America, whereas it requires several decades to build up 

 definite silvicultural practice. 



Second, silvicultural practice is essentially a local consider- 

 ation, varying in important details from forest to forest. 

 Generalizations and the intelligent use of knowledge gained 

 by others develop slowly under such a condition. 



Third, application of knowledge to treatment of a forest is 

 seriously hampered when such knowledge is fragmentary. 

 Silvics, which in theory affords the scientific basis for silvi- 

 culture, is still in its infancy so far as furnishing definite 

 information for use of practitioners on numerous important 

 problems is concerned. 



Despite these difficulties and deficiencies a body of in- 

 formation has been built up as to methods and lines of pro- 

 cedure from which, as the starting point, the details of local 

 silviculture must be worked out. 



The need to-day for silviculture in practice is colossal and 

 coextensive with the area of non-agricultural land. Business 

 conditions control the practice of silviculture as in a similar 

 way they do the practice of agricultural science on farm lands. 

 Intensive silviculture, like intensive agriculture, pays only, 

 where markets for products are accessible and prices high. 

 A crude application of silviculture is practicable to-day on a 

 great majority of the forest lands. 



Silviculture, like agriculture, requires expenditure or in- 

 vestment made in order to secure some crop or return of 

 more value than would be obtained without such action. 

 The return in agriculture comes within one year or at most 

 within a few years after the expenditure is made, while in the 

 practice of silviculture the return is delayed several decades. 

 In either case the intensity of the work and th'e amount of 



