MANAGEMENT OF WHITE PINE 361 



to those on the cleared strips, although the reproduction has been, 

 on the whole, more successful. Abundant seedlings have come in on 

 the drier sites where the competition with woody vegetation was not 

 too keen. This method, like the preceding, is open to the serious 

 objection of greater cost due to the smaller, scattered areas. Further- 

 more, even if the groups of young growth become established, it is 

 difficult later to log the surrounding uncut timber without undue 

 damage or expense. 



The Selection Method. — Small areas cut over by the selection 

 method where only single large trees or groups of trees were cut, 

 have resulted in fair reproduction. It is not, however, a practicable 

 means of handling pure pine, being too costly and not calculated to 

 provide the necessary density and growing conditions for the new 

 crop. 



The Seed Tree Method. — All experiments with the seed tree method 

 have proved failures. In many cases the trees blew down. Even 

 when windfirm trees could be selected, woody and herbaceous growth 

 covered the ground before sufficient pine seedlings got started. 



The Shelterwood Method. — Of all methods tested this has resulted 

 in the best reproduction. The first cutting has consisted in a imiform 

 thinning in which mainly the overtopped and defective trees were 

 taken. This meant the removal of about one-quarter of the trees and 

 ^>ne-fifth of the volume per acre. Up to the point where windfall 

 l^ecomes a risk the heavier the thinning the better was the reproduc- 

 tion. Stands so treated have in five years shown as many as 25,000 

 seedlings per acre. Where the overwood was allowed to stand more 

 ihan five years the reproduction became stunted and too weak to 

 recover promptly when the removal cutting was made. 



MANAGEMENT NOW IN PRACTICE 



The cutting method now in practice on the Harvard Forest, though 

 based largely on the outcome of the experiments above described, was 

 adopted with considerable reference also to practical and financial 

 considerations. The rotation for white pine is set at GO years. As the 

 working plan is based upon the principle of a sustained annual yield, 

 final cuttings have to be made each year. In this respect the property 

 is in the same case as that of a wood-working concern which requires 

 a steady annual supply Since SQ:tc\ years for white pine occur not 

 oftcner than once in three years, this means (hat any cutting method 



