9 



branch wood, was computed first in cubic feet. a Adding the volume 

 of the group of trees on each sample plot, the total contents of the 

 plot were obtained, and from this the total volume of the grove could 

 be reckoned. In all cases the results were reduced to the unit of 1 

 acre. The volume in cubic feet was reduced to cords by using the 

 factor 0.86 as the divisor. 



TABLE 1. Comparative height of the principal sped.es for planting in eastern Nebraska. 



The table shows that all the species except silver maple make a bet- 

 ter height growth during the first five years than for any other five- 

 year period. Silver maple increases its rate of height growth over 

 that of the first five years up to the twentieth year, and thereafter 

 slowly declines. Cottonwood, green ash, and black walnut decline in 

 height growth after the thirtieth year, the first two very rapidly. 

 Black walnut maintains a very uniform growth up to that time. 

 Hardy catalpa grows at a fairly uniform rate up to the twentieth 

 year, and then gradually declines. Honey locust grows somewhat 

 more slowly than hardy catalpa for the first ten years, but leads after 

 that time, and its height growth up to the fortieth year is very uniform. 



TABLE 2. Comparative diameter, breasthigh, of the principal species for planting in eastern 



Nebraska. 



a The stump was considered as a cylinder and the stem and branches as paraboloids. The volume 

 of the sample tree being known, the total volume of the group or class it represented was obtained by 

 the use of the following formula: F=vx-, in which F=volume of the whole group or class; v=vol- 

 ume of the sample tree; S= basal area of group or class represented by the sample tree; 8= basal area 

 of the sample tree. 



10067 No. 4506 2 



