322 A TEXT-BOOK OF BOTANY 
seedlings to develop; so that in a forest properly managed 
there are trees in every stage of development, from seed- 
lings to those ready to be cut. Such management is being 
adopted not only in large forests that are prominent sources 
of wood-supply, but also on individual farms, where the 
wood-lot is as carefully managed as the grain-field. De- 
tailed plans for such management can now be obtained from 
the Bureau of Forestry or from State foresters, so that 
ignorance is no longer any excuse for mismanagement. 
184. Protective forests.—This name has been suggested 
for those forests that are used primarily as a soil cover. 
Such forests are used also as supply forests, but their chief 
purpose is to cover the soil. Forests are great regulators 
of water-flow, retaining the water of rains and letting it 
pass gradually into the streams. When they are removed, 
streams that formerly contained a steady supply of water 
are subject to alternations of flood and extremely low water. 
When forests are removed from water-sheds and the head- 
waters of rivers, this result becomes disastrous. The head- 
waters of prominent rivers are generally in mountainous 
regions; and the removal of forests there results not only 
in flooded rivers, but also in slopes stripped of their soil and 
deeply gullied. In such regions, therefore, the forest both 
regulates the water-flow and protects the soil. 
In consequence of these facts, the Government has set 
apart certain forest areas upon the head-waters of the prin- 
cipal rivers as forest reservations. These reservations are 
guarded from fire and from ruthless cutting, but are cut for 
timber under proper forestry management. Especially are 
such reservations imperative in the West where irrigation 
is necessary, which must depend upon a steady supply of 
water from the mountains. On January 1, 1905, there were 
sixty-two such reservations in various parts of the West, 
including over sixty-three million acres. States also have 
established forest reservations, most prominent among 
