Southeastern Washington and Adjacent Idaho. 29 



The station in the firs and tamarack on the north slope of the 

 mountain and only about 60 feet from the top, was in a forest of 

 nearly pure second growth Pseudotsuga and Larix. These trees 

 are mostly about thirty-five years old and are equally distributed, 

 with a few relict pines and about three per cent, white fir. It 

 may be noted that the graph of evaporation here is decidedly 

 lower than in any other habitat. 



FIG. 7. Graphs showing the march of soil water to a depth of 10 inches 

 in various plant communities on Kamiak Mountain. 



The evaporation stations at Viola gave results comparable to 

 those shown on the chart for Kamiak. Without exception, the 

 average daily rate of evaporation in the prairie on the southwest 

 slope was higher than that of the pines on the northwest slope. 

 Likewise, the graph of evaporation in the fir- tamarack forest 

 showed a continuously lower rate than that in the pines. 



29 



