b. There is a fully stocked, manageable component which is capa- 

 ble of release. 



c. Thinning would not yield merchantable material, and would not 

 involve the felling of near-merchantable trees. 



Possible combinations: (13, 20), (13, 20, 23), (20, 23), (13, 20, 22, 

 23), (20, 22, 23), (13, 20, 22), (20, 22). 



Code 21: Stand conversion 



This treatment code automatically implies the need for regeneration, 

 following conversion. 



Stands which qualify for this category include all precommercial stands 

 which have unmanageable insect or disease problems. Also included are non- 

 vigorous precommercial stands which would not be capable of release, if 

 thinned. In the case of lodgepole pine, it includes all non- vigorous stands 

 which are older than 50 years. 



Seedling and sapling stands which are grossly understocked with crop 

 trees, but which contain a significant stocking of undesirable (excess) trees, 

 are also included under this category. 



Possible combinations: (13, 21). 



Code 22: Sanitation 



This code applies to all crop stands whose health can be improved 

 through intermediate cuttings, i.e., cuttings which reduce the source of the 

 insect or disease problem (not applicable for most defoliating insect prob- 

 lems) . 



This category does not include stands which are in need of commercial 

 harvest or precommercial stand coversion because of insects or disease, low 

 vigor, or stagnation. It applies only to stands which can be sanitized and 

 managed as a crop stand. 



Possible combinations: (13, 22, 33), (22, 33), (12, 13, 22), (12, 22), 

 (13, 22), (13, 22, 23), (22, 23), (13, 20, 22), (20, 22), (13, 20, 22, 

 23), (20, 22, 23). 



Code 23: Regeneration of understocked areas 



Code 23 includes all precommercial stands which are inadequately stocked 

 with desirable or acceptable crop trees. The minimum standard for adequate 

 crop tree stocking is 210 trees per acre, with at least 70% of the area 

 stocked. 



This code by no means implies a particular method of regenerating 

 understocked areas. Under code 23, options may exist for use of existing 

 seed sources, site preparation, planting, direct seeding, or combinations of 

 these methods. In many cases, this treatment code represents situations 

 where the stocking of undesirable excess trees must be reduced prior to 

 supplementing the existing understocked crop stand with additional regen- 

 eration. In such cases, this treatment would occur in combination with 

 precommercial thinning (code 20). 



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