64 



A Volume Table for Algaroba 



By C. S. JuDD, Superintendent of Forestry. 



The severe wind storm of last December afforded an oppor- 

 tunity of obtaining certain measurements of windthrown algaroba 

 trees, Prosopis juliflora, D. C, for the construction of a volume 

 table for cordwood which may be useful to wood dealers and 

 owners of tracts of algaroba land who desire to know the amount 

 of wood in the trees standing on their land. 



The use of a v'olume table in Hawaii is probably very little 

 known to most residents because this is not a timber country, but 

 on account of the increasing importance of the algaroba tree 

 which, since its introduction in 1828, has spread over almost 80,- 

 000 acres of what was formerly waste or poor grazing land, in- 

 creasing the value of such land many fold, this volume table, the 

 first constructed for algaroba in these islands, may be of value to 

 those who have occasion to use it. 



It should be considered, however, in the nature of a preliminary 

 table of local application which would not be suitable for all con- 

 ditions of algaroba tree growth and hence it should be used only 

 in the nature of a guide. The method of its construction and the 

 character of timber involved are described at the head of the 

 table. When used in closely-grown and tall timber where the 

 yield of wood would naturally be greater, the values for the 

 different diameters would have to be increased according to ex- 

 perience based on the yield secured from actual cuttings. 



A volume table shows the average contents of standing trees of 

 different sizes and is used to estimate the yield of wood standing 

 on specified tracts. It is intended only for estimating a large 

 number of trees because it is compiled from the average of a 

 number of measurements and is necessarily inaccurate as applied 

 to a single tree. The volumes of individual trees of the same 

 species and same diameter may vary as much as 20 per cent. 



The use of a volume table is very simple. The total content- 

 of trees of any given diameter are computed by multiplying the 

 number of trees of a certain diameter by the average volume 

 given in the table for that diameter. For convenience, the diame- 

 ters of the trees are measured at breast height, or at four and a 

 half feet above the ground, and the volume table is based on this 

 measurement. For example: If it is desired to determine the 

 number of cords of wood in ten standing algaroba trees, four of 

 which have a diameter of 12 inches and six of which have a 

 diameter of 20 inches, by reference to the volume table it will be 

 seen that the average volume of a 12-inch tree is .50 cord, or half 

 a cord, which gives two cords for the four trees. Similarly, the 

 average volume of a 20-inch tree is 1.50, or a cord and a half, 

 which when multiplied by the number of trees of that diameter 

 gives nine cords for the six trees. These results, when added to- 

 gether, give a total volume of 11 cords for the 10 trees. 



