RKfiEXEHAriOX 11V R(K)T-SU('KKRS. 387 



1. Influence of species, soil and climate. 



This influence has been studied on pp. 78-7U, to which the 

 student is referred. 



2. Influence of the age of the stems cut lack. 



In reference to this the student should read Condition XV on 

 page 92. He will there see that trees generally continue to throw 

 up root- suckers long after they have ceased to be able to produce 

 stool-shoots. 



3. Healthiness and soundness of the parent tree. 



Provided the tree is neither in its decline nor half-dead nor in 

 full decay, suckers will always be produced ; and, indeed, as often 

 said before, a certain amount ot want of vigour increases the 

 tendency of a tree to develop them, although there can be no 

 doubt that a strong healthy tree will, when cut down, throw up 

 stronger, if not more numerous, suckers than a weak tree similarly 

 treated. Local decomposition of the roots is not necessarily 

 opposed to the production of an abundant crop of healthy suckers, 

 unless of course the rottenness is due to fungoid disease, which 

 we know is contagious. 



4. Life of forests reproduced successively l>y means of root-suckers 



alone. 



We have no data for determining the relation this period hears 

 to the natural longevity of the species concerned, but it is pro- 

 bable that it is more prolonged. In the case of sissu, we know 

 that this species can go on reproducing itself thus for several 

 centuries, for on no other hypothesis can be explained its presence 

 (since sissu can reproduce itself from seed only on flooded land) on 

 flat ground which is now several hundred feet above the nearest 

 stream and at least two miles away from the main drainage line 

 of the stream basin. 



5. Manner of cutting. 



If the trees are still young enough to grow up again from the 

 stool, it is evident that unless the stool is grubbed out or cut 

 below the level of the lowest dormant buds, a very large proportion 

 of the reserve food will be used up in the formation of stool-shoots, 

 thus reducing by so much the number and vigour of the root-suck- 

 ers produced. If simply cutting down the trees has not the 

 effect either of producing a sufficient number of suckers or of 

 getting them to come up over a sufficiently wide area round each 



