17 



impossible to open them out sufficiently in one operation to prevent them 

 becoming congested again in a few years without cutting so -many stems 

 that those left are unable to stand upright. Hence it is considered that 3 

 thinnings will be required. Two thinnings would have advantages over 3, in 

 that they would be easier to carry out, but it is doubtful if in 2 thinnings 

 the immense number of stems which have to disappear between the ages 

 of 5 and 20 years, can be removed without the risk of the stems left being 

 too isolated to stand. The first thinning should take place at 6 years. A 

 thinning earlier than this would have advantages, but the crops until they 

 have been opened to grazing are so dense that it is difficult to enter them 

 and consequently thinnings in 5 years old coupes would be very difficult to 

 carry out. During the 20 years, 1916-17 to 1935-36, the average age of the 

 crops to be felled will be about 22 years, hence if 3 thinnings are to be 

 made starting at 6 years, the second and third thinning should be at 11 and 16 

 years respectively. The following thinnings are therefore prescribed : 



7. Tkinningt (6 years old crops). 



II. Thinnings (11 years old crops}. 



///. Thinnings (18 years old crops). 



43. The method of carrying out the thinnings found most successful 

 , , . . hitherto is first to have all dead and fallen 



Tno execution of the thinnings. , j. j. j i -n , -i 



stems including standards cut and collected. 



An untrained guard can then with very little practice have all the suppressed 

 stems marked and cut. After this has been done a light thinning is marked 

 by a skilled officer. This method gives satisfactory results in crops 10 16 

 years old which have not previously been thinned. In crops 6 years old 

 there is very little dead wood and unless a skilled officer has plenty of time 

 to spare for the work it will be necessary to use an untrained guard to 1 

 mark all suppressed stems which should be cut before the skilled officer marks 

 the thinnings. 



