PLANT SUCCESSION IN AVASHINGTON 



289 



Ocoupyinp; a place in the succession b(^twoen the prairie and 

 the fir-tamarack stages, is the yellow pine. This tree is able to 

 invade the prairie even without the protection of an intervening 

 shrubby stage, although often a growth of Opulaster pauciflorus, 

 Prunus emarginata, Spiraea corymbosa, or Ceanothus spp. precede 

 it in the ordinary course of succession. Likewise the Douglas 

 fir closely follows the pines and, as already pointed out, the white 



Fig. 8. A view in the cedar association on Cedar Mountain near station 

 No. 10 



fir may sometimes precede the tamarack, thus giving rise to a 

 mixed association of pine, Douglas fir, and white fir. When 

 conditions become more meseophytic, the Douglas fir-tamarack 

 stage is followed by the climax cedar association This last 

 association is not represented either at Kamiak or Viola. 



TUE PLANT WOni.D. VOL. 17. NO. HI, 1914 



