18 



KERRY WOODS. 



due to wind at high elevations even in what appear to be perfectly 

 sheltered localities a count was made of the number of damaged 

 larch tops in each group, with the following results : 



* Double or triple leaders. t Referred to later, see p. 19. 



The total percentage of bad tops has been represented 

 graphically as a function of the elevation in the diagram on 

 p. 17. 



The trees with double tops may of course develop into good 

 timber trees, but those in which the crown has taken a permanent 

 set owing to exposure to wind seldom recover sufficiently to grow 

 into large trees. 



The fact that in Groups L 5 and L 6 50-60 per cent, of the present 

 crop is damaged at an age of 20 years indicates that it is impossible 

 to raise a pure crop of larch at such elevations and under such 

 conditions. The upper limit for pure larch appears to be between 

 Groups L 4 and L 5 , i.e. about 1,300 feet, on such a slope. 



Future Development of Sample Groups. 



As a guide to the future development of these groups, older 

 trees were felled in another wood known as Cefn Craig. The 

 conditions as regards soil and exposure are similar to those in 

 Cwm Golog, but the crop is very thin on the ground. The first 

 tree (8 L) growing in a very thin wood, elevation 1,160 feet, was 

 51 years of age with a total height of 70 feet 4 inches, a volume 

 of 20' 5 cubic feet and a diameter at breast height of io'4 inches. 

 The form factor was 0*494. 



The second tree, 40 years old, elevation 1,400 feet, had the 

 following dimensions (Tree 1 1 L) : 



v = 6'97 cubic feet = 44-3 feet. d=7'25 inches, f = -474. 



