34 BULLETIN 24, U. S. DEPARTMENT OF AGRICULTURE. 
of most other hardwoods. In burning cane, briers, grass, and weeds 
special care is nevertheless advisable to keep the fire under control, 
und where adjoining stands of young timber might be injured it may 
even be important to surround the burning area with plowed fur- 
rows for fire lines. 
No preparation of the ground is adequate which fails to leave 
the mineral soil exposed. Burning of slash under some circum- 
stances may be sufficient, but as a rule it will be necessary to drag 
the surface with a spike-toothed harrow or similar implement. The 
cost of dragging should seldom exceed 50 cents per acre. Swamping 
of small trees and undergrowth can usually be effectually done for 
$1.50 to $2 per acre, making a total of $2 to $2.50 per acre for the 
preparation of the ground. In many bottom lands, however, half of 
this amount will be enough. 
Grazing of hogs in the bottoms may serve to expose the mineral 
soil even better than dragging. Cattle, sheep, and goats may like- 
wise assist in reducing the herbaceous growth. If logging is carried 
on during the summer, the underbrush and weeds will often get 
quite a start before the seed ripens the following spring, unless graz- 
ing is encouraged. As‘soon as reproduction starts, however, grazing 
should cease. 
From the standpoint of preparing the ground there is plainly an ad- 
vantage in logging during the late summer and fall, say from August 
to November, inclusive. Very little growth of weeds, grass, cane, 
etc., will come up on cleared areas after the first of August, and, 
moreover, the sprouting capacity of bushes and trees is low during 
these late months. Conditions in the bottoms will seldom permit of 
logging in the spring early enough to prepare the ground for the 
cottonwood seed of the same season. Wherever feasible, winter op- 
erations are entirely consistent with good management. 
Proper preparation of the ground, however, will, in many in- 
stances, be out of the question. Where the undergrowth is especially 
dense and consists of vines, such as poison ivy or peppervine, the 
cost of eradicating it will frequently be prohibitive. Such areas 
can only be planted. | 
MIXED HARDWOOD STANDS. 
Where cottonwood is the only species of great commercial im- 
portance on an area the aim should be to favor it alone. If, how- 
ever, valuable species are growing with it, some of these may be 
favored as well. By favoring other species along with cottonwood 
the liability of total failure in securing reproduction is reduced. 
Another advantage is the beneficial effect of the other trees upon the 
cottonwood itself in shading the forest floor, thus preventing the 
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