Part II] Hole: Regeneration of Sal ( Shorearobusta ) Forests 53 
seedlings would be 10 years and their height 15 inches (see para. 23 
(9) above). 
If such seedlings are then exposed to favourable conditions of soil- 
aeration and moisture in cleared patches and strips, as recommended 
in the system proposed above, it is believed that the majority of them 
will persist and develop vigorously. In this way, the area to be artifi¬ 
cially sown during the 15 years of the regeneration period proper could 
be reduced by at least one half. This area could, if necessary, be still 
further reduced by lengthening the period of preparatory treatment. 
In Experiment IV above, it has been shown that removing the over¬ 
head cover, in a patch 60 feet in diameter, from above 3-years-old 
seedlings, raised in the shade, gave very poor results, 79 per cent, of 
the existing seedlings dying within 3 months of the felling, see paras. 
26-28 above. 
In this case, however, the seedlings were only 3 years old and about 
6 inches high. Ten-years-old plants 15 inches high would obviously 
have a much better chance of surviving. 
Application of the Dehra Dun results to other forests. 
55. Finally, nothing which has been said above strongly advocating 
the application of the modified Group-cwm-Strip system, as an experi¬ 
mental measure, in certain selected areas is intended to prejudice 
trials with other methods of concentrated regeneration. The Dehra 
Dun experiments have, it is believed, proved that 
(1) the primary factors which prevent or retard the healthy, vigor¬ 
ous growth of sal seedlings are bad soil-aeration and drought, 
and the damage done by these factors can be greatly reduced 
by suitable fellings. 
(2) The fellings should aim at reducing the soil moisture and expos¬ 
ing the soil to the sun in those localities where, or at those 
seasons when, bad soil-aeration is most injurious. 
(3) The fellings should aim at increasing the soil moisture by facili¬ 
tating the access into the soil of dew and light showers, and 
by diminishing water-loss due to evaporation and transpi¬ 
ration, through the provision of suitable side-shade, in those 
localities where, or at those seasons when, drought is most 
injurious. 
(4) In addition to the fellings, burning off the leaf-layer, hoeing 
the soil and judicious weeding are subsidiary operations by 
means of which also the soil-aeration and soil-moisture can 
be improved. 
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