APPENDIX. XVII 



Granted suitable soil conditions the next factor necessary for 

 successful regeneration is light. The varying light requirements 

 of species are well known and sufficient importance is devoted 

 to this matter in text-books dealing with European forestry. 

 But in India in the case of many species considerable doubt 

 still remains as to the conditions of light suitable for their 

 reproduction. 



Light and moisture are intimately bound up. Side shade 

 from the south for instance may be responsible for a more or less 

 constantly wet soil and is often the injurious factor in such cases 

 rather than a deficieny of light rays for photosynthesis. Light is 

 therefore in this essay used as a relative term meaning not merely 

 " light " such as is measured by a photographic exposure meter but 

 in addition the inseparable factors of soil and moisture conditions 

 which are directly caused by fellings in the overwood for the 

 purpose of admitting light to the soil. 



In the case of the deodar it has been stated that this species 

 is a shade bearer but this is not so. Many years of investigation 

 into this matter have brought out exactly what are the light 

 requirements of this tree. 



" Deodar germinates under all conditions of light and shade 

 but the time soon comes when seedlings growing in shade must 

 be given plenty of light if they are to survive. It has been stated 

 that the group system is suitable for the deodar, but this system 

 is only suited to a shade bearer, and so far from falling into this 

 category the deodar must be classed among the light demanders. 

 A gap 100 by 80 feet with seed bearers around, clear felled : S. W. 

 aspect, 6,000 feet elevation, was completely regenerated in 1914 

 and promptly fenced. Vigorous seedlings now survive in the 

 upper half which received most of the light, but in shady places 

 round the edges they have all died away. We have thus in the 

 experiment eliminated every cause except the factor light, and it 

 is want of this alone which must have caused the death of the 

 seedlings. Another somewhat similar group in a different locality: 



