SILVICULTURAL MANAGEMENT OF BLACK SPRUCE IN MINNESOTA 17 



a general infestation of dwarf mistletoe (Arceuthobium pusillum) 

 w.hich stunts and deforms the trees. Fire is, of course, an effective 

 means for controlling dwarf mistletoe because, as Weir (SO) has 

 pointed out, the mistletoe can spread only by seeds from plants grow- 

 ing on living hosts. 



Figure 12. — Black spruce does not regenerate after slash fires in clear-cut areas 

 because the seeds in the cones and on the ground are consumed by the intense 

 and prolonged heat. An upland stand of black spruce with some paper birch 

 and aspen in mixture. All of the spruce and the larger birch were cut. The 

 slash burned accidentally soon after logging. 

 792021° — 48 3 



