TIMBER; FORESTRY 353 
Regulation of the water supply is, however, the most 
important service which forests render, aside from their 
value as sources of timber. It is a matter of common 
observation that when a wooded region is stripped of its 
trees, brooks and rivers are subject to violent floods in the 
season of heaviest rain or at the melting of the snows, 
while during the drier months springs fail and streams 
run low, so that their beds may be only a series of pools. 
These facts are due to the regulative effect of the forest 
floor on the distribution of water which falls as rain or 
snow. On bare ground, not even covered with grass, a 
large portion of the rainfall is at once carried off to the 
nearest streams. Even on grasslands the run-off is rapid, 
as is shown by the quick rise of prairie rivers after a heavy 
rain. But the leaf-covered forest floor, often carpeted 
with moss, holds water like a sponge and continues to de- 
liver it for many days after every heavy rain or period of 
melting snow. This gradual delivery of water, part of it 
draining off along the surface, part of it soaking into the 
soil and then slowly finding its way underground into 
springs and streams, makes the watercourses of a heavily 
forested region comparatively permanent and constant, de- 
livering considerable water at all seasons of the year and 
rarely overflowing their banks within a few hours after 
rains. For this reason it is of the utmost importance that 
wooded regions like the White Mountains, the Adiron- 
dacks, the central and southern portions of the Appala- 
chian system in which many streams have their sources, 
should be protected by appropriate legislation as soon as 
they are seriously threatened by the lumberman. 
