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. 
TT LN Poh tt 5 
Y CO/? 
Pa 
SawENSSooES 
Fic. 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 
