RELATION OF MENSURATION TO FORESTRY SUBJECTS 3 



determining either the proper investments and expenses, or the probable 

 returns and profits from such an enterprise. 



4. Relation between Forest Mensuration, Stumpage Values and the 

 Valuation of Forest Property. In determining the value of forest 

 property for sale, exchange, or the appraisal of damages, it is necessary 

 first to know what the mature standing timber is worth on the stump 

 previous to cutting. This is known as stumpage value. The stumpage 

 value of standing timber is derived from the value of the finished prod- 

 ucts and is influenced by four factors, namely, the species of wood, 

 its quantity, its quality, and the unit price of the product. Forest 

 mensuration by means of a forest survey determines as accurately as 

 possible the first three factors. By determining through an appraisal 

 the price of stumpage for the different kinds and qualities of timber 

 found on the area, the value of the timber may be found. 



The value of young timber and of forest soil can be calculated after 

 the possible yields at given ages have first been approximated and the 

 stumpage value has been appraised for this final yield. 



5. Relation of Mensuration to Other Forestry Subjects. The rela- 

 tion of Forest Mensuration to other subjects in forestry is shown in 

 Fig. 1. In the threefold division of forestry indicated, mensuration 

 falls in the mathematical or business group, but is included in the phys- 

 ical branch of that group which deals directly with the forest. 



Mathematics is the basis of Mensuration, since the latter subject 

 deals primarily with quantities. But as both timber estimating and 

 growth data must usually be expressed on terms of area or acreage, 

 Mensuration rests directly on Surveying. 



Mensuration in turn furnishes the quantitative data required by 

 the science of Forest Finance as a basis on which to compute the cost of 

 production and the probable returns from forestry and to indicate the 

 choice of methods to use in forest production. Although it falls in the 

 business group, and is a basic subject underlying Forest Management, 

 Mensuration is a statistical science similar to Forest Finance. Neither 

 subject constitutes an applied science, which is the characteristic of 

 Forest Management. Mensuration is therefore not a direct subdivision 

 of Management, but a distinct subject preparatory to Management. 



6. Absolute versus Relative Accuracy in Mensuration. Forest 

 Mensuration attempts to secure as close an approach to mathematical 

 accuracy as the conditions of the problem, the use to which the data are 

 put, and the cost of the work will permit. In scaling, the volumes of 

 logs are determined before sawing, and in timber estimating, the contents 

 of trees and stands are obtained before felling. But no log rule will 

 give the exact quantity of lumber which will be sawed from a given 

 log, and no tree volume table can predict the output in boards from a 



