80 BULLETIN 1105, U. S. DEPARTMENT OF AGRICULTUEE. 



point to the desirability of relatively few (four or five) good seed 

 trees rather than a large number of poor or mediocre ones, and they 

 confirm the conclusion announced under " Seed supply " that the 

 large groups of small blackjacks prevalent in most stands are entirely 

 inadequate for reseeding cutover areas. The one great disadvantage 

 of the method is that it removes the young, rapidly growing trees 

 which should constitute the future growing stock. So vital is this 

 fault that it bars the method from further consideration, notwith- 

 standing the fact that it appears to have the greatest possibilities in 

 the way of reproduction. 



The group-selection method in a large measure takes advantage 

 of the good and eliminates the bad features of the other two methods. 

 In short, it promises to secure reproduction without disregarding 

 other aims of silviculture. It permits the removal of enough timber 

 to warrant logging operations without sacrificing the forest capital. 

 It aims to avoid excessive losses from deterioration of mature tim- 

 ber, but at the same time to leave enough seed trees in the large 

 diameters to insure reasonably prompt reproduction. It does not 

 free the seedlings from the root competition and shade of older 

 trees in the same degree as the scattered seed-tree method, but 

 it goes considerably further in this direction than does the shelter- 

 wood method. Unless it is decided to convert the forests into even- 

 aged stands, which is not contemplated in the near future, a certain 

 amount of suppression of seedlings by immature trees must be ac- 

 cepted. Considering all the conditions imposed by the character 

 and composition of our virgin stands and by economic cond'itions, 

 the group-selection method comes nearest to meeting the silvicultural 

 requirements of western yellow pine in this region at the present 

 time. 



Results on the various sample areas cut according to the group 

 selection method indicate that reasonably good reproduction may 

 be expected in about 20 years. Other things being equal, the period 

 will vary, within certain limits, with the amount of seed available. 

 The fact that the 1918 seed crop alone promises to accomplish the 

 task which would ordinarilj^ require three or four seed crops does 

 not warrant the assumption that we have a margin which may be 

 taken up by reducing the number of seed trees. Such a coincidence 

 of seed supply and rainfall as occurred in 1919 is of too rare and un- 

 certain occurrence to be relied upon in a safe plan of management. 

 On the other hand, provision should be made, by leaving sufficient 

 seed trees, for taking full advantage of such fortunate circiunstances 

 when they do occur. This might be used as a criterion as to the 

 minimum number of seed trees required. Applying this standard, 

 the group selection cutting in Group VII barely meets the require- 

 ments. The fact that the seed crop in this locality was. only what 



