Southeastern Washington and Adjacent Idaho. 



33 



the principal trees, but a considerable amount of white fir and 

 some spruce (Picea engelmanni) are also present. The under- 

 growth is rather sparse. 



The evaporation in the cedar forest was always lower than that 

 in the preceding developmental communities. The data taken in 

 the cedars are shown in Fig. 9. Those of the other forest sta- 



MY 



//Vf 



Is 



cm sec 



'Qiyoft 



Fin 





con 



wccn 



" 



V 











X 







FIG. 9. Combined graphs showing the average daily evaporation rates 

 at all the stations in the prairie, pine, and fir-tamarack communities on the 

 buttes and mountains. The lowest graph gives the average daily evapo- 

 ration in the Thuja consociation. 



tions are shown combined with all other readings taken in the 

 fir-tamarack forest. For the sake of comparison, the chart also 

 gives combined graphs showing the average evaporation rates in 



33 



