(pine 



After self-thinning has gone on for a hundred 

 years or so, the ranks have been so thinned that 

 there are openings sufficiently large to allow 

 other species a chance to come in. By this time, 

 too, there is sufficient humus on the floor to allow 

 the seeds of many other species to germinate. 

 Lodge-pole thus colonizes barren places, holds 

 them for a time, and so changes them that the 

 very species dispossessed by fire may regain the 

 lost territory. Roughly, the lodge-pole will hold 

 the ground exclusively from seventy-five to one 

 hundred and fifty years, then the invading trees 

 will come triumphantly in and, during the next 

 century and a half, will so increase and multiply 

 that they will almost exclude the lodge-pole. 

 Thus Engelmann spruce and Douglas fir are 

 now growing where lodge-pole flourished, but let 

 fire destroy this forest and lodge-pole will again 

 claim the territory, hold it against all comers for 

 a century or two, and then slowly give way to 

 or be displaced by the spruces and firs. 



The interesting characteristic of holding its 

 cones and hoarding seeds often results in the 

 cones being overgrown and embedded in the 



189 



