INCREASING THE YIELD. 



45 



vent destruction of small yellow poplar seedling, or to fence areas on 

 which the young growth could be injured. 



Unless plantations are protected, the destruction of a part of the stand 

 is likely to result in understocking. The results of understocking are: 

 short-bodied and scrubby trees, the stems being set with numerous large 

 knots so that the lumber is low grade ; and in spite of the relatively large 

 diameters of the individual trees a low yield per acre. 



Elimination cuttings. In natural stands of yellow poplar on cut-over 

 land there will often be a very large proportion of low grade species. 

 When these are rapid growing and might seriously interfere with the 

 growth of the poplar, or entirely crowd it out, it is necessary to eradicate 

 them. The material which is cut in this manner often will have no sale 

 value, the cutting being made entirely for the benefit of the mature stand. 

 Such cuttings can sometimes be combined with thinnings 



FIG. 7. A pole stand of hardwoods, containing much yellow poplar killed by 

 a severe spring fire. Note sprouts around bases of trees. 



Thinnings. Thinnings are made for the purpose of accelerating the 

 growth of the remaining trees in a stand. They cover two periods. Those 

 which are made in very young stands of sapling and pole size, the result 



