INDIAN FOREST RECORDS. 
Vol. VI,] 1917 
[Part II 
STATISTICS 
Compiled in the Office of the Silviculturist, Forest 
Research Institute, Dehra Dun, during 1915-16. 
INTRODUCTION. 
rTlHE compilation of statistics relating to the growth and outturn of 
-L Indian trees has been hampered in the past chiefly by lack of 
continuity and by absence of uniformity in the methods of measure¬ 
ment adopted. Mr. Troup’s Note on the collection and tabulation of 
statistical data advanced proposals for a common system which might 
be applied over the whole of India. These proposals were considered 
by the Board of Forestry in 1913, and the methods and forms suggested 
were held to be generally suitable with such modifications as local con¬ 
ditions might demand. Volume measurements of forest crops were to 
be carried out by the Silviculturist or by special officers working in co¬ 
operation with him, but measurements of individual trees, of felled 
material, and of girth increments could be collected locally. 
Some progress has been made in the adoption of a uniform system 
of measurements, but lack of continuity still accounts for the impossibil¬ 
ity of utilizing much good work. Experience has indicated that this 
difficulty can be surmounted only by the appointment of special officers 
to establish, to supervise, and to maintain sample and experimental 
areas. This is the function of the Silviculturist, but even in 1913 the 
Board of Forestry recognized that the appointment of a special officer 
in each province was highly desirable owing to the urgent need of ex¬ 
tending silvicultural research and to the impossibility of one officer 
controlling sample plots throughout India. 
The figures in this publication have been compiled from the follow¬ 
ing sources :— 
(I) Periodical girth-measurements of selected trees, recorded 
in registers by divisional forest officers; the registers have 
been sent to the Silviculturist, the trees have been classi¬ 
fied into girth-classes, the average increment for each 
girth-class calculated, and curves prepared for each sample 
area, from the curves, the girth for each 10-year period 
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