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Harvesting methods most commonly used in Montana forests include: 



(1) The selection system is the removal of mature and iirmature 

 trees singly or in groups at intervals. The objective of this 

 system is to maintain an uneven-aged stand with regeneration 

 established almost continuously; 



(a) Individual tree selection involves removing individual 

 trees rather than groups of trees. This method tends to 

 favor shade-tolerant species; 



(b) Group selection is the removal of small patches (less than 

 two acres) to create a mosaic of even-aged groups within 

 an uneven-aged forest; 



(2) The shelterwood system involves a series of cuts removing mature 

 trees over a relatively short portion of the rotation. This 

 system encourages establishment of an essentially even-aged stand 

 under partial shelter of the remaining trees; 



(3) The seed tree system entails removing nearly all trees in one 

 cut. A few desirable seed-producing trees are left, distributed 

 over the area, to naturally reseed the stand. 



(4) The clearcutting system is the harvesting in one cut of all trees 

 in an area to create an even-aged stand. 



An important part of many silvicultural systems is site preparation. The 

 objective of site preparation is to create conditions necessary for 

 establishment of a new forest stand (Packer, 1971). Factors often con- 

 sidered with site preparation are: 



(1) Disposing of logging residue; 



(2) Reducing or eliminating plant competition; 



