﻿46 BULLETIN 13, U. S. DEPARTMENT OF AGRICULTURE. 



burning over of the surface prior to the seed fall is necessary. The 

 areas dealt with are ordinarily so large that disengagement cuttings 

 are out of the question. 



The seed-tree method has been employed in the white and Nor- 

 way pine stands on the Minnesota National Forest (see Plate VII). 

 Owing to the inadequacy of the law under which cuttings were made, 

 however, it has not proved satisfactory except under accidental 

 combinations of circumstances, such as the occurrence of severe 

 ground fires before and not after a seed fall. The law provides 

 that ,10 per cent (originally 5 per cent), by volume, of the trees 

 above 10 inches diameter breast high shall be left as seed trees. 

 Since no adequate provision was made for the distribution of these, 

 spaces left without seed trees were often too large, and very little 

 reproduction resulted. The stand was cut not only during seed 

 years, but also in years when there was absolutely no seed produc- 

 tion. In the absence of cultural fires to free the ground from com- 

 peting growth before the seed fall, the benefits of cutting during 

 seed years are minimized, since most of the reproduction, even if 

 abundant, is killed by the dense brush that rapidly springs up. On 

 some areas which had been burned over during the spring or summer 

 of a seed year and logged the following fall and winter, reproduction 

 was excellent. On many of these, however, the young pine was killed 

 by subsequent fires, and before the next seed year the ground was 

 again covered with brush. 



In lumbering old stands by the shelterwood method the first cut- 

 ting should be made during a seed year and should be heavy enough 

 to provide sufficient light for the pine seedlings without unduly 

 encouraging the growth of brush. If reproduction is satisfactory — 

 that is, if it should average at least 2,000 well-distributed seedlings 

 per acre — a second cutting should be made during the first heavy 

 seed year after the young pines are 5 or 6 years old. The stand may 

 be cut clear at this time if the fire risk is small and the expense of 

 leaving seed trees prohibitive. If, however, too much brush has 

 sprung up since the first cutting, the ground should be thoroughly 

 burned over in the spring or summer of the seed year in which the 

 second cutting is made and seed trees or even enough of the stand 

 to warrant a later cutting left on the ground. 



Should the shelterwood method be thought too expensive, the 

 seed-tree method may be used with good results if the cutting — 

 made during a full seed year — is preceded by a thorough surface 

 burning. The seed trees should be selected in advance from the 

 most windfirm of the pines, and should be protected from surface fires 

 by trenching or some other means. They should be well distributed 

 at least 2 or 3 to the acre. Before each subsequent seed year, 

 areas on which reproduction is poor should be carefully burned over. 



