Climax series 



A group of habitat types that at climax will be dominated by the same 

 tree species. 



Commercial species 



Tree species presently or prospectively suitable for industrial wood 

 products. 



Commercial thinning 



A thinning in which the cut trees are large enough to be removed and 

 utilized, regardless of whether their sale offsets the cost of the thin- 

 ning. 



Commercial timberland 



Forest land producing or capable of producing crops of industrial wood 

 and not withdrawn from timber utilization. (Note: Areas qualifying as 

 productive forest land have the capability of producing in excess of 20 

 ft^/acre/year of industrial wood under management. Currently inaccessi- 

 ble and inoperable areas are included, except where the areas involved 

 are small and unlikely to become suitable for production of industrial 

 wood in the foreseeable future). 



Condition class 



A method of expressing the general health of the range by comparing 

 the expected percentage of the climax composition contributed by each 

 species to the actual composition. No invaders (plants present only be- 

 cause of a disturbance, such as grazing) are counted and only the 

 amount of increasers (plants that increase under grazing pressure) that 

 would be present at climax are included. All of the decreasers (plants 

 that decrease under grazing pressure) are counted. 



County and municipal lands 



Lands owned by counties and local public agencies or municipalities, or 

 lands leased to these governmental units for 50 years or more. 



Crown class 



A classification of trees based on dominance in relation to adjacent 

 trees in the stand as indicated by crown development and amount of 

 light received from above and the sides. 



Crown density 



The percentage of the forest floor that is covered by tree crowns. For- 

 est land with greater than 70% crown density is considered to have no 

 range value for livestock. 



Cull 



Portions of a tree that are unusable for industrial wood products because 

 of rot, form, or other defect. 



Decreaser (decreasing range plant) 



Plants which decrease under heiivy grazing pressure. These are usually 

 the more palatable plants and the ones that the livestock prefer to eat. 



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