Germination of Forest Trees 27, 
It is quite natural to wonder how these values compare with 
values that have been obtained in the woods. Probably the com- 
parison of the light values obtained in the dense shade with some 
of the lowest values obtained in the woods would be most interest- 
ing. Clements (2) found light values from 0.12 to 0.05 under 
mature lodgepole pine in Colorado. He observed that Douglas 
fir occurred very rarely in densities below 0.05. Wiesner found 
the same value in this case. Pearson in Arizona found that 
western yellow pine seedlings grow fairly well in a light intensity 
from 0.309 to 0.414. White fir was found in good condition in 
light intensities of from 0.027 to 0.068 and healthy young growth 
of Engelmann spruce was found in intensities of from 0.033 to 
0.062. In Oregon Pearson found such tolerant species as alpine 
‘fir, Engelmann spruce, western hemlock, and Lowland fir grow- 
ing in light intensities from 0.021 to 0.029. The western larch 
however showed only poor development in a light intensity of 
0.353. This will be sufficient to indicate that the light in the 
dense shade tent compares with some of the lowest light intensities 
that have been measured in our western forests. In this con- 
nection it is interesting to note that white pine, black locust, red 
oak, and western yellow pine lived for two to four mouths in the 
dense shade tent, as is evidenced by the fact that stem and root 
measurements were taken on these species during the last days of 
these investigations. 
In connection with the light experiments a very important fact 
soon became evident. In spite of the fact that all three cultures 
were watered every evening at the same time and in the same 
degree, it soon became evident from mere observation that the 
top layer of soil by the following evening had dried out to very 
different degrees in the three cultures. The open light culture 
was noticeably the driest and the dense shade culture the moistest 
so far as the top layer was concerned. This fact led to taking 
systematic moisture samples to determine the exact difference 
in moisture content. These samples were taken once a month, 
three evenings in succession and these readings were averaged 
into one reading. The table of soil moisture contents is given 
below : 
