96 Forest Club Annual 



I 



as all Forest officers have in the Woodman's Handbook, U. S. 

 F. S. Bulletin 36. The volume of this average tree may be de- 

 termined in a volume table or by cutting two or three down and 

 averaging their contents after having scaled them. It is better 

 still to make a volume curve from the measured contents of three 

 or more average trees of different diameters. The volume of the 

 average tree multiplied by the total number of trees represented 

 in the group will give the total volume of the trees on the average 

 acre. The total number of acres of merchantable forest in the 

 sale area, computed from the map, usually by counting the 

 squares, multiplied by the average volume per acre gives the 

 total volume for the tract. 



An accurate estimate of the timber, then, is about equally 

 dependent upon both an accurate map from which the area of 

 the merchantable forest is determined and an accurate average 

 acre analysis. 



In the same manner the stand per acre of Engelmann Spruce 

 to be cut is ascertained, which multiplied by the total acreage 

 of merchantable forest gives the total amount of this species to 

 be sold. These operations are repeated for each species. 



The seedlings and saplings by species are totaled and com- 

 puted for the average acre and the percentage of each found. 

 The number of trees per acre above 6 inches in diameter by 

 species to be left are noted from the analysis and the percentage 

 of each species calculated. % 



The total acreage in sample plots divided by the total area 

 in merchantable forest will give the percentage estimated. Then, 

 with the areas in burns, cutover land and other classes of non- 

 merchantable forest computed from the map, the examiner finds 

 that every bit of information required on the "Estimate Sheet" 

 can be derived from data gathered as outlined above and worked 

 up as here shown ; nothing is left to be supplied by the imagina- 

 tion. It is suggested that in recording the sample plot data 

 only the trees that should be cut for purely cultural reasons be 

 placed in the column headed "To Cut." He can combine the 

 volumes of the trees "to be cut" and "to be left" and apply the 

 Von Mantel formula to determine the felling budget. In short, 

 with the data thus obtained he can analyze the stand and gov- 

 erned by the analysis have the fellings executed along the lines 

 which his judgment dictates. 



