willows: their growth, use, and importance. 9 
posed grove was practically destroyed, while the other gave promise 
of unimpaired vigor for another 10 or 20 years. 
In young willow plantations cattle, horses, sheep, and hogs eat 
the green shoots with avidity, and much damage may be done during 
the first 10 years of the life of the plantation. After that a small 
amount of browsing is often beneficial, as it clears the main stems 
of watershoots and small branches. Further injury by stock after 
this consists in barking the tree trunks, which hastens decay. The 
effect of grazing on the soil in the plantation is very harmful, and low 
yields and early decline mark the plantation where this practice is 
common. 
FLOODS. 
Willows on the flood plains of streams are more or less subject to 
injury during periods of high water. This has been noted as especially 
bad in willow plantations where the crop is pollarded, leaving a 
trunk from 8 to 10 feet in height. The injury to the trunk from 
floating debris and ice has resulted in the shortening of life, so that 
one or even two or three crops grown on a 7-year rotation have been 
lost. Such injury can be prevented by cropping at the ground and 
allowing the young vigorous shoots that are removed every few 
vears to receive the blows rather than the stump, on the health of 
which depends the life of the pollard. 
LIFE HISTORY OF THE BLACK WILLOW. 
COMMERCIAL RANGE. 
Of the native American species the black willow is by far the most 
iportant, on account of its wide range and its rapid growth under 
a variety of soil and moisture conditions. Over the greater part of 
its range this species is a tree willow and generally of considerable 
; ze. As a timber tree the black willow reaches its best develop- 
ment in the rich alluvial bottom lands of the lower Mississippi River 
and the lower portions of its tributaries. The quantity of merchant- 
able black willow is much smaller than that of the cottonwood that 
formerly grew in this region, but to-day the cottonwood is rapidly 
disappearing and there is little doubt that there will soon be as much 
k ending black willow as cottonwood between Cairo, 111., and Baton 
Rouge, La. On the whole, however, it will average much lower in 
quality. 
Most of the willow stands are found below the 35-foot stage of the 
river. They often occur above this mark, but are generally old trees 
and on being cut are replaced by cypress, gum, locust, ash, or other 
hardwoods. The same holds true for cottonwood to a large extent; 
the reproduction of old stands is very uncertain and the under story 
pecies generally takes the ground. 
8210°— Bull. 316—15 2 
