FOREST AREAS AND SOIL WATER 
155 
face layers. There is in this case as in previous cases an evident 
gravitational movement, not alone from surface to subsoil, but 
also from the top to the foot of the slope. This is apparently 
in greater volume in the timber soils and becomes manifest at the 
foot of the slope much nearer the surface than in the open. 
The showers during the period of August 17 to 20 were ac- 
companied by intervening periods of comparatively high evapo- 
ration. They were neither heavy nor of long duration. As a 
result almost without exception the surface soils show a loss dur- 
ing this period except at the foot of the timbered slope. The 
subsurface and subsoils on the whole show a gain. , This gain 
tends to become apparent earliest in the open soils, the timber 
soils again showing a tendency to lag behind. Also, with the ex- 
ception of the clay subsoil at the top of the open slope, the timber 
soils show the highest gains. In the subsoils the moisture content 
remains approximately level at the top of the timbered slope but 
shows a decided rise at the middle and foot. 
The rains of the 22d and 30th affected the soil moisture curves 
as did the previous periods of precipitation, and here again one 
of the outstanding facts is the delayed rise in the lower layers, 
especially at the middle and foot of the slopes, and the decidedly 
greater rises of the timber over the open soils. 
SUMMARY 
The comparative results of these studies are in many respects 
less clearly defined than those for the evaporation studies. A 
cursory consideration appears to indicate rather irregular results, 
with less clearly defined relationships of forest cover to soil mois- 
ture and especially to the movement of ground water than is the 
case with evaporation. It is true that the results obtained and 
the deductions made here should form the basis of further study, 
and they are presented as indications of existing relationships. 
However, certain rather direct influences are apparent. 
On the whole, the timber soils used in this study show greater 
sand content and therefore would be expected to show, from the 
standpoint of physical composition alone, a more rapid rate of 
permeability and a lower moisture holding capacity than the finer 
textured soils of the open. This is of especial interest since it 
undoubtedly explains the relatively high moisture content of the 
subsoils of the open slope. Moreover, it emphasizes the im- 
portance of the influence of forest cover, in that actual compari- 
son shows the coarser forest soils used in these studies to be cap- 
