138 FOKESTRY WORK 



require more growing space than slower-growing trees on 

 poor soil. 



Hardwoods must be given more space than conifers, 

 because the best hardwood timber has large annual 

 rings, while the best coniferous timber has narrow rings. 



The old rule in many places was to allow an average 

 distance between the trees equal to one-third of their 

 height ; but however good this rule may have been when 

 growing Oak for shipbuilding, it is of no use now, when 

 timber is needed straight and free from knots. 



According to Continental tables of thinnings, the 

 average distance usually left between the trees is from 

 one-eighth to one-sixth of their height when in the pole 

 stage. 



According to Maw in his book " The Practice of 

 Forestry," the number of poles per acre at 45 to 50 years 

 (after thinning) and at the end of a rotation on Quality II. 

 soil should be — 



655 at 50 j'ears. Final crop, 150 at 120 years. 



The figures for the final crops are, however, much 

 lower than those given in Continental tables. 



It is a great mistake to make haphazard thinnings; 

 for instance, when a certain class of pole is needed for 

 estate purposes, the temptation to go into a plantation 

 and cut out the number required should be resisted, for 



