340 
Indian Forest Records. 
[VOL. 1. 
therefore that under this method the possibility calculated for a 
period equal to the number of years which it takes a second class tree 
to become first class may be equal to the whole of the existing Class 
I trees flus the whole or a part of the Class II trees, the latter figures 
depending on the condition of the forest dealt with, and on the num- 
ber of the annual coupes. Accordingly a study of existing working 
plans based on the Oudh Method will reveal a vast amount of differ- 
ence as regards the proportion of Class II trees taken into the possi- 
bility. 
The results of the enumerations given in detail in Appendix A 
Example I All Class I Working Plan* for the Naini Tal 
trees pks of Class II Cantonment forests. United Provinces, 
frees. show that — 
We have a total of 2,381 trees of all species over 4^ feet girth. These 
may all be removed during the next 20 years, should sylvicultural considerations 
•admit of this. 
Though we have no satisfactory data enabling us to fix the average rates 
of growth of the various species, it may be assumed that most of the trees take 
40 years to pass from the second to first class, so that in addition to all trees 
of over 4J feet girth, one-half of those in the second class (which total 3,808) 
should theoretically enter into the possibility during the next 20 years, but there 
are several reasons why we cannot accept this in practice, the principal being- - 
(i) though it is probably fairly correct to say that a third class tree takes 
on the average 40 years to enter the second class, our data are 
unreliable and we must allow of a safety margin ; 
(ii) an allowance must also be made for deaths, windfalls, etc.; 
(iii) the physical nature of the ground is often such as to render the re- 
moval of a tree inadvisable; 
(iv) portions of the forest area are open to grazing; this demand may 
increase; at any rate it will probably not diminish and grazing 
cannot be entirely stopped. 
Under these circumstances extreme caution is indicated in the removal of 
the existing stock of 2nd class trees, and it is therefore considered advisable 
to allow one-tenth of the stock of these trees to enter into the possibility during 
the next 20 years. 
The annual possibility will thus be all trees of over 4i feet girth plus 
one-tenth of the existing stock of trees 3 feet to 4| feet girth divided by 20. 
As the cantonment authorities have been accustomed to a volume outturn 
and understand it, the possibility is fixed in maunds of 100 lbs. 
Using the factors given in para. 45 of the working plan report, and the 
result of the enumerations given in an Appendix, the total possibility for the 
next 20 years works out at 61,613 maunds, or an annual average outturn of 
=3,080'6 maunds. It must be borne in mind that this is a maximum 
20 ’ 
* Working Plan for the Naini Tal Cantonment forests, Western Circle, United 
Provinces, by T. J. Campbell, I.F.S., 1904. 
I 
