ROUGH CONVERSION. 231 



1. Mode of Conversion to l>c Applied. 



The mode of conversion suitable to any particular felling- 

 area depends on the adaptability of the wood and the demand 

 for it. 



(a) The Adaptability of the Wood. 



This varies with the species, form, dimensions and quality 

 of the wood. 



j. ,S),yr/V'.v tif \YnoiL 



The uses of the different kinds of wood will be discussed in 

 Chapter YI. ; it will be shown that conifers are used chiefly 

 ,-is timber and that, of broadleaved species, it is the light- 

 demanding trees, and, above all, the oak, which yield the 

 most valuable timber. 



The following remarks refer to the usual forms of woods 

 met with. Pure beech high forest is frequently a fuel forest, 

 and only a small portion of the yield is then treated as timber. 

 Sometimes, owing to a favourable market, as, for instance, in 

 the chair-making districts of Buckinghamshire and Oxford- 

 shire, or in Belgium, this is not the case ; but frequently the 

 timber yield of a pure beechwood is not more than 10 to 20 

 per cent, of its total yield. 



AYherever aspen, birch, willows, limes, etc., are mixed with 

 beech, there is a rise in the timber yield, but this can be con- 

 siderable only when oak, ash, sycamore, or elms are mixed with 

 the beech. Such mixtures are the most valuable forms of 

 broadleaved high forests, as in them the light-demanders 

 thrive best and attain their best shape. The timber yield 

 of such forests may be 20 to 30 per cent, of their total yield, 

 and even more. A mixture of conifers in beech forest is 

 very valuable, as the former then attain their best dimensions 

 and quality. 



In the Kottenbuch forest range, which is the range richest 

 in fine oak trees of the whole Spessart, the yield of oak- 

 timber between 1860 and 1880 was 26 per cent, of the total 

 yield. 



The yield of oak-timber does not depend so much on the 

 quantity of oak-trees in a mixed wood as on their age and 



