MEASUREMENTS OF TREE REQUIRED FOR CLASSIFICATION 157 



times substituted. To this height the stump height is added, and the 

 total recorded to the nearest foot. The height of a rounded or irregular 

 crown is measured to a line drawn at right angles to the bole, and tan- 

 gent to the highest point of crown. Height may also be obtained by 

 adding together the lengths of the separate sections of the bole, plus 

 the distance from the top of last section to tip of trees. 



Character of crown may or may not be required. It is useful in 

 hardwoods where separate tree classes may be desired, and in any 

 species where growth is being investigated and as the index of 

 form, as indicated in Chapter XVI. On felled trees, two measure- 

 ments are taken. Width of crown is measured as the tree lies, at 

 widest point, at right angles to stem. Length of crown is the dis- 



Fig. 25. — Method of measuring a log twice at right angles to obtain the average 



diameter. 



tance from tip to the point where the lowest vigorous and well-shaped 

 green branch joins the bole, or better still, at a point on the bole, oppo- 

 site the lower limit of the green crown or foliage. Some judgment is 

 required in excluding from crown-length small, feeble or straggling 

 single live branches which may have survived by accident on one side 

 but do not form part of the main crown of the tree. Dead branches 

 or knots form no part of the crown. 



The position or class of the crown in the stand may also be described, 

 as open-grown, dominant, co-dominant, intermediate, or overtopped. 

 This is best judged before felling. 



The following definitions have been adopted as standard by the Society of 

 American Foresters. 



Crown Class. All trees in a stand occupying a similar position in the crown 

 cover. The crown classes usually distinguished are: 



