Southeastern Washington and Adjacent Idaho. 99 



These may be shaded by too dense thickets of various shrubs, 

 which may spring up from underground parts, and largely re- 

 place the herbaceous vegetation. But usually the shrubs form a 

 protection against wind and excessive evaporation. The trees in 

 turn suppress the shrubs and the 'mature forest, usually similar 

 to the one preceding, is replaced. 



Studies of reforestation in burns of varying severity show 

 more or less incompletely the several stages of the subsere. How- 

 ever, continued investigation in these and in completely burned 

 areas indicates the following serai stages, some of which may be 

 telescoped or even lacking in any one particular burned area. 



Salix-V actinium ASSOCIES 



V actinium consocies 



Rubus consocies 



Salix consocies 

 Epilobium-Cirsium ASSOCIES 



Cirsium consocies 



Epilobium consocies 

 Agrostis-Bromus ASSOCIES 



Bromus consocies 



Agrostis consocies 

 Funaria-Marchantia ASSOCIES 



Marchantia consocies 



Funaria consocies 



There remains only to be considered briefly reproduction in 

 the burns in the northeastern part of the area and especially 

 along the Palouse River where the lodgepole pine plays a sig- 

 nificant role. The wide range of the lodgepole habitat from very 

 moist to very dry soil, its rapid growth and early reproduction as 

 well as its inability to withstand fires or to endure shade are too 

 well known to necessitate discussion here. 



The forests of this part of the region, where lumbering oper- 

 ations have been going on for a long time and burns of all ages 

 occur, are mixed throughout with lodgepole pine, the amount of 

 which may vary from a few towering relict trees to nearly pure 

 stands. 



99 



