NORWAY PINE IN THE LAKE STATES. 27 



CLEANING OR WEEDING. 



To produce timber of high quality it is essential in most cases to 

 tend the stand practically from the start. One of the mam cultural 

 operations is to clean or weed the young stand of undesirable trees. 

 While such an operation maybe permissible from a financial standpoint 

 in a mixed hardwood forest, it would scarcely be justified in the case 

 of Norway pine. To clean or weed the young Norway pine stands 

 will entail an expense of from $2 to $4 per acre. Two dollars at 5 

 per cent compound interest amounts to $697.82 for a rotation of 120 

 years, and few operators could afford this expenditure. Where the 

 owner maintains a protective force the rangers may make systematic 

 weedings. For example, if jack pine is temporarily suppressing the 

 Norway pine, the ranger can top the jack pine and lessen the strug- 

 gle for light. Norway pine seedlings under aspen or underbrush 

 can be liberated. If this weeding can be done in connection with 

 other duties, even at a small additional expense, it is certainly worth 

 while. In Minnesota, for example, there are thousands of acres of 

 natural forests of Norway pine, from 10 to 30 years old, which deserve 

 attention from the owners, and which it would be profitable to hold 

 in view of the increasing demand for small mine timbers. 



THINNINGS. 



The removal of undesirable or competing trees from a stand is 

 called thinning. This reduces the loss which ordinarily takes place 

 in the struggle for light. The silvicultural value of thinnings in 

 Norway pine can not be questioned, although they are not of the 

 same vital importance as in a mixed forest. In a widely spaced 

 plantation thinnings would probably not be needed before the 

 twentieth or thirtieth year, but will be necessary after that. Timely 

 thinnings are important in securing natural reproduction, since they 

 result in a final stand of trees with well-developed crowns, thus 

 insuring abundant production of seed. Moreover, every lumberman 

 would prefer to cut 88 20-inch boles, rather than 338 13-inch, 1 because 

 wide lumber brings better prices than narrow boards. Under 

 present conditions thinnings on a large scale are justified only when 

 the sale of the products at least pays the cost. The owner of a small 

 area of timber can improve his stand without expense by selecting 

 the small poles needed for farm construction from dense groups of 

 Norway pine, instead of adopting the possibly more convenient pro- 

 cedure of cutting a portion of his woodlot clear. Thinnings in pine 

 stands should begin early, and be made lightly and often. In a 

 dense Norway pine stand the first thinning should be made when the 

 trees are from 20 to 30 years old, removing from 10 to 15 per cent of 



1 See Table 11 for yield data on unthinned stands on Quality II soil. 



