SII^VICUIvTURE OF VVKSTERN VKELOVV PINE 883 



the climax form of forest — the form which, because of the conflicting 

 relation of fire, seeding and establishment, has become through the ages 

 the prevailing form of forest. For another thing, it indicates that a 

 clear cutting method may be in entire accord with Nature, if the even- 

 aged succession form of forest is allowed to grow until maturit\' and 

 then cut so as to reproduce in the same way. 



It is almost a dictum among foresters to base the silvicultural system 

 upon the form of virgin forest found on the ground. When the form 

 found is the climax forest, this is not always wise. The foresters of 

 India learned this after 30 or 40 years of experience with chir pine. 

 They found the virgin forest largely in irregular, many-aged stands 

 much as we find yellow pine, and they managed it at first by a selection 

 method. Now they find it better forestry to cut chir pine so as to 

 regenerate it in even-aged masses. 



In general a silvicultural method of cutting should first of all be one 

 in agreement with Nature, then one which produces the most profitable 

 growth and which is most practical of accomplishment. It is sometimes 

 stated arbitrarily that the selection forest is the only one which pre- 

 serves the forest conditions of the site. When a forest by Nature grows 

 even-aged and will repeatedly and vigorously do so on the same site as 

 does Douglas fir, it is safe to say that it maintains the fertility of the 

 site for the purpose of timber production. Indications are that yellow 

 pine will generally do the same thing. 



For a forest of pure composition, it may be said in general that it 

 must grow even-aged to produce the most profitable volume growth ; 

 because the individuals being necessarily of uniform tolerance, either 

 the smaller trees in the uneven-aged stand are inhibited in growth or 

 the stand is open to permit their free growth, and in both cases the net 

 volume production is restricted.^ In most regions Nature provides a 

 balance which prevents the restriction of the net growth. Douglas fir 

 is a well known example in which an uneven-aged stand may be had 

 without loss of growth because the more tolerant understory trees of 

 hemlock and cedar are able to grow profitably in the shade of the over- 

 wood firs. But' as has already been shown, in the arid yellow pine 

 region there is no other species, regardless of tolerance, which will 

 grow on the typical yellow pine site. It would be well if exact figures 

 showing the yield of even-aged as against uneven-aged forests of yellow 

 pine could be given, but until there has been longer experience in forest 

 management this cannot be done. Approximate figures are indicative, 



