35 



may become so slender that they cannot stand upright, and 

 the tops may become so restricted that they no longer prop- 

 erly perform their functions. By the removal of some of 

 the trees the beneficial influences of the struggle may be re- 

 newed from time to time and the harmful effects may be 

 avoided. In other words, thinning prevents the stimulative 

 competition from becoming a destructive competition. 



154. Thinnings are influenced by market conditions. 

 If there is a market for small material, a young stand may 

 be thinned earlier and the thinning may be repeated oftener 

 than when there is a market for only the larger trees. 

 A young stand may be thinned as soon as the material 

 to be removed has reached such a size that its sale will 

 pay for its removal; and it should not be thinned again 

 until the material to be removed has accumulated in suf- 

 ficient quantity to yield a profit, or at least to pay tor 

 its removal. If this rule is followed, the improvement of 

 the stand which results from the thinning will be a net gain. 

 In some cases a thinning might be made even at a slight ex- 

 pense and still be profitable in the end; but it is safer to fol- 

 low the rule given above. Where it is practicable to thin in 

 this State, the application of the rule would mean a moderate 

 thinning when the stand is 25 or 30 years old and a repeti- 

 tion of it every 10 or 15 years thereafter until maturity is 

 reached. Farmers are in a better position to practice thin- 

 ning than some other classes of owners; because there is 

 nearly always a demand on the the farm for firewood, posts, 

 poles, and other small material. Even where there is no 

 outside market for small material, thinnings may be prac- 

 ticed on the farm to the extent of the small material con- 

 sumed on the farm. 



