﻿26 BULLETIN 24, U. S. DEPARTMENT OF AGRICULTURE. 



Table 5. — Yield of cottonwood stands on upland soil in Iowa, and Minnesota. 



Location. 



Age. 



Number 

 of trees 

 per acre. 



Average 

 diameter 

 breast- 

 high. 



Average 

 height. 



Yield per acre, 

 Scribner. 



Remarks. 



To 12-inch 



top. 



To 10-inch 

 top. 



Lee County, Iowa . . 

 Do 



Years. 

 25 



25 

 45 



50 



55 



56 



10S 



88 

 131 



80 



88 



25 



Inches. 

 13.0 



13.8 

 15.3 



18.3 



16.5 



24.8 



Feet. 

 80 



82 

 84 



100 



94 



107 



Bd.ft. 

 1,700 



4,100 

 12, 900 



15, 800 



13, 100 



15,000 



Bd. ft. 

 5,100 



6,600 

 15,600 



18,100 



16, 800 



18, 100 



Scattered, with many 

 associate species. 

 Do. 



Allamakee County, 



Iowa. 

 Jackson County, 



Iowa. 

 Monona County, 



Iowa. 



Scott County, Minn. 



Pure stand. 



Very dense pure stand. 



In Missouri Valley, less 

 humidclirnate, dense, 

 pure. 



Maple, elm, ash, etc., in 

 mixture. 





It is probable that some of these stands have been cut to a slight 

 extent, but it is not likely that on upland soil in this region cotton- 

 wood will cut more than 20,000 feet per acre at 50 years of age. At 

 this age, however, it has already reached maturity and is losing 

 rather than gaining. Yields of between 15,000 and 20,000 board feet 

 ought to be possible in 35 to 40 years. One or two plantations in 

 Iowa on good bottomland soil have yielded more, as may be seen 

 from Table 6. 



Table 6. — Yield of cottonivood on bottomland soil in Iowa. 



Location. 



Harrison County. 

 Monroe County . . 



Years. 

 34 

 35 



Number 

 of trees 

 per acre. 



126 

 137 



Average 



diameter 



breast 



high. 



Inches. 

 14.5 

 13.3 



Average 

 height. 



Feet. 



Yield 

 per acre. 



Bd.ft. 

 23,850 

 24, 500 



Original 

 spacing. 



Feet. 



7Jby6 



8iby8§ 



At least one of the plantations has occasionally been thinned. 

 Moreover, the trees had plenty of room for early growth, and it is 

 probable that they were cultivated for the first few years. In the 

 case of these plantations, however, the estimates take in all straight 

 logs to a top diameter of 6 inches, for even such small-sized material 

 is actually sawed up for farm use. Considering, however, only logs 

 j0 inches find over in diameter, northern stands of cottonwood will 

 probably seldom yield more than two-thirds as much saw timber as 

 stands of the same age in the lower half of the valley. 



MANAGEMENT. 



ADAPTABILITY OF COTTONWOOD. 



If cottonwood stands are to be maintained permanently some sys- 

 tem of management is essential. Its demand for plenty of direct 



