CONTEXTS. 



Page. 



Timber estimating— Continued. 

 Contents of standinp^ tree? — Continued. 



Volume tables 61 



By diameter only 61 



By diameter and standard log length 62 



By diameter and tree classes 63 



By diameter and height 63 



Factors that affect the accuracy nf estimates 64 



Determination of the contents of stands 65 



( V»veriiig the whole area 65 



Kstimate by the eye 65 



Estimate by inspection of each tree 67 



A method of cniiMng a *' forty" by small squares 68 



A method used in open woods 70 



Covering only part of the area 70 



A method used in the Lake States 70 



Strip surveys 72 



Distribution of strip surveys 73 



Preparation of a forest map 74 



Measurement of the trees 75 



Recording measurements 76 



Number of strip surveys required 77 



Compulation of results 77 



Estimate by counting logs 79 



Systematic plot method 80 



A method used on the Pacific Coast 81 



Scattered or arbitrary plots 81 



Advantage of strip surv^eys 82 



Use of heights in estimating 82 



A meth(Hi \ised in Southern yellow pine 87 



Accurate plot surveys 89 



The choice of methods for rst iinalinLT 89 



G»-owth of trees <H) 



Diameter growth 90 



Height growth 91 



Volume growth . 91 



Entire viilume 91 . 



Table giving approximal*' growth per cent 93 



Board foot volume 94 



