FOREST AREAS AND SOIE WATER 
153 
ficient here to maintain the moisture content in the lower layers 
and to add a considerable surplus to the surface. In the open, 
on the other hand, the rise is apparent in all the soils immediately 
and is greatest in the subsoil. It continues to August 5 in the 
surface but begins to drop in the subsurface and subsoil after 
August 2. Apparently then, there is in this case a more rapid 
gravitational movement and a greater influence of evaporation 
in the open than in the timber. This is particularly evident when 
the tendency of the curves following August 6 is considered. 
At the middle of the slopes for the same period there appears 
a well marked continuous rise in all soils. This is greatest for the 
surface of both timber and open slopes and for the subsurface of 
the timber. Furthermore, the rise in the timber continues until 
August 8 in all soils, while in the open there occurs a drop after 
the 6th, except for the subsoil. The rains were heavy and the 
Fig. 31. Soil moisture content in per cent of air-dry soil for foot of timbered and 
open slopes — stations la and XII, respectively. For amount of rainfall see note, 
fig. 29. 
