﻿COTTONWOOD IN THE MISSISSIPPI VALLEY. 33 



so that their shade may not suppress any of the young growth. 

 Most pure stands, however, arc accessible to the river, which makes 

 it practicable, as a rule, to return for any seed trees within a year or 

 two of the first cut. With only a few logs to handle it will often be 

 possible to wait till high water and then float them out to the river 

 bank, thus obviating the much greater expense of hauling. In such 

 cases there would probably be no extra expense connected with leav- 

 ing seed trees. If hauling were necessary, however, it might cost 

 fully 50 per cent more to get out this scattered material. After the 

 short interval of only a year or two, little if any additional swamping 

 would be necessary to open up the former logging roads, but the 

 haulers would lose considerable time in locating and loading the 

 scattered logs and would probably get out no more than two-thirds 

 as much per day as when working in heavier stands. If hauling 

 under ordinary conditions costs $3 to $4 per thousand, it might in- 

 crease in the latter instance to from $4.50 to $6 per thousand. The 

 additional $1.50 to $2 per thousand feet would then represent the cost 

 of leaving seed trees. If these are left as recommended, they should 

 not average over 750 board feet per acre, which would make their 

 cost at most run from $1.20 to $1.50 per acre. 



PREPARATION OF THE GROUND. 



Pure thickets of cottonwood, up to 20 or 25 years at least, are quite 

 free from undergrowth, but at the age of 30 or 35 years a large 

 variety of shrubs, vines, and weeds usually come up under the main 

 stand. Such growth consists largely of peppervine, poison ivy, 

 briers, privet, dogwood, and innumerable species of herbaceous char- 

 acter. In the more open mature stands undergrowth and weeds 

 often cover most of the ground. In addition, there are often numer- 

 ous suppressed or overtopped trees of less valuable species, such 

 as sycamore, hackberry, and elm. Such trees are usually small, but 

 if left after lumbering would soon develop spreading crowns and 

 shade much of the area. All such growth is detrimental to cotton- 

 wood reproduction. To insure natural renewal of the stands, there- 

 fore, it will not be sufficient merely to leave seed trees, but- in addi- 

 tion the ground must be cleared of all undergrowth. If the resulting 

 slash is very abundant, it may be best to pile it Avith the cottonwood 

 tops. In normally dense stands, however, this will seldom be neces- 

 sary, since here the brush is not rank. Burning the slash will seldom 

 be of benefit, except in the case of a rank growth of cane or weeds, 

 which may be killed off by a carefully controlled surface fire. Sur- 

 face fires do not run rapidly in most parts of the bottoms because 

 of the small amount of inflammable material. Dry cottonwood 

 leaves, moreover, are said to be much less inflammable than those 



