49 



ACRE-YIELD MEASUREMENT. 



In measuring the trees on the sample area special attention should 

 be given to the classification of trees resulting from varions stages of 

 development which they have attained, the basis of such classification 

 being height and crown development. For the purposes at hand it is 

 sufficient to consider only three classes, namely, dominant, codominant, 

 and oppressed. Dominant trees are those which overtop their neigh- 

 bors and possess fully developed crowns. Codominant trees are those 

 which, although being of the same height as the dominant trees, pos- 

 sess poorly developed crowns, usually compressed on all sides by neigh- 

 boring trees. Oppressed trees are those whose crowns are still less 

 developed than those of the codominant trees; they are not only com- 

 pressed, but also somewhat overtopped by the neighboring trees. It is 

 advisable to adopt a conventional system of marking the trees of each 

 class of dominance by blazing the bark of trees below the height of the 

 stump, when the class of dominance assigned to a tree while standing 

 may be either verified or rejected afterwards when the tree is felled and 

 measured in detail. 



DEDUCED RESULTS. 



The sample area leaves a general impression upon the mind of the 

 timber investigator. This impression should be utilized by converting 

 it into figures of forest economic value, which can be easily remem- 

 bered. It is exceedingly desirable that the timber investigator should 

 deduce all the results relating to the acre-yield in the manner shown in 

 Blank ^o. 2 immediately after the sample area is described and meas- 

 ured. Thereafter, when, while the details are fresh in mind, the timber 

 investigator meets with similar forest conditions, he is in a position to 

 estimate the standing timber at a glance, using previous experiences as 

 a basis of judgment. 



THE MEASURING OF FELLED TREES FOR ANALYSIS. 



When the trees on the sample area are felled and sawed into logs the 

 timber investigator should begin the detailed measurements. The saw- 

 yers are followed, and as each tree is sawed into logs the measurements 

 are made before the logs are removed from the place where the tree fell. 



The tree is calipered first at breast height, and then at intervals of 

 8 feet from the ground, until a point on the trunk is reached where the 

 diameter measures 5 inches or less. In keeping a record of the meas- 

 urements, the entry for each tree includes its serial number; height of 

 tree; height to base of crown; character of growth, i. e., whether dom- 

 inant, codominant, or oppressed; condition of timber, i. e., whether 

 sound, defective, crooked, wind shaken, clear, or knotty; amount of mer- 

 chantable timber (determined by scaling the logs of the tree right on 

 the spot where it is felled); the position of the tree and surrounding 

 species, and other remarks. Blank No. 3 of the appendix gives the 

 5107— No. 20 4 



