56 FORESTRY BRANCH BULLETIN NO. 33 



required from the employees of the lumber companies. In selection cuttings on the 

 Deerlodge Forest a successful beginning had been made at burning the brush imme- 

 diately after the felling of the trees. 



The marking of timber to be cut was very thoroughly done. When the timber 

 was cut in strips, the boundaries of the areas to be reserved were blazed. In selection 

 cuttings, every tree to be cut was blazed both at breast-height and below stump- 

 height. All blazes were stamped ' U.S.' with a die on the back of the marking axe. 



VOLUME, GROWTH AND YIELD TABLES. 



Most of the tables are based on measurements taken of trees felled in logging 

 operations on timber limits in the Crowsnest Valley. All the trees on eight plots in 

 different locations, comprising one and a half acres, were measured for diameter and 

 height growth, and also for volume to furnish data for a volume table and to give 

 the volume of the present stand. The yield at different ages was computed from the 

 growth and volume figures. Only trees ten inches and over were measured, as that was 

 the merchantable limit. 



The measurements were taken in fully stocked, normal mature stands in order 

 to get growth figures that would be conservative when applied to individual trees or 

 to stands of less density. The measurement of all the trees on the plots was done in 

 order to get a correct average, and to get the proper proportion of large and small 

 trees. It also enabled the computation of yield per acre. 



VOLUME. 



The diameter inside bark of the top of each log was measured and the volume 

 of the tree computed according to the Scribner log rule. 



DIAMETEK-GKOWTH. 



Diameter growth was measured on the stump by decades. The growth figures 

 for each plot were averaged and plotted separately in order that the growth of aver- 

 age trees for each plot might be known and used in computing the yield of each plot 

 at various ages. The plots were classified into two sites and from the curves of the 

 individual plots, the average growth on the two sites was obtained. The average 

 growth of all the trees measured was also computed and plotted. 



HEIGHT-GKOWTH. 



The age of the upper end of each log was counted, and the lengths of logs and 

 top measured. The height figures were averaged similarly to the diameter figures. 

 The time required to grow to stump height was counted in. 



SEEDLING HEIGHT-GROWTH. 



The table is based on figures obtained in various localities under average con- 

 ditions. 



YIELD. 



The volumes of the trees as actually scaled on each plot were added together, 

 and the present stand per acre obtained. The intermediate yields were computed by 

 calculating the dimensions of average trees for the plots. The growth of imaginary 

 trees possessing those dimensions was found from the growth-curves. By con- 

 sulting the volume table, the volumes of the imaginary trees at various ages were 



