146 TENDING OF YOUNG HIGH FOREST, ETC. 



able ; on good soil individual trees are quicker to assert them- 

 selves. 



In Nature the selection system is largely observed, and 

 this danger is to a great extent averted in an uneven-aged 

 wood growing under the selection system, for the patches of 

 trees of the same age are small, and those on the outside 

 avail themselves of more light and air. 



With reference to thinning, some foresters classify 

 trees as : 



(1) Dominating or Vigorous. 



(2) Dominated. 



(3) Suppressed. 



(4) Dead and Dying. 



Dead and dying trees should always be cut and removed 

 from the forest, or the danger from insects, fungi, and fire is 

 increased. For the same reason suppressed trees in conifer- 

 ous woods should always be removed ; the vigorous and 

 dominated trees, alone, being usually left. Though at each 

 chinning, the vigorous trees should usually be individually 

 considered and any dominated trees removed if likely to 

 interfere with the growth of the former in the next few 

 years. 



Some dominated trees must often be removed if inter- 

 fering with each other. Sometimes from bad management or 

 other cause the vigorous trees have an unduly large crown 

 and branch development in proportion to the length of their 

 stems ; such trees should always be removed : they occupy 

 more ground than should be allotted to them. 



When, however, dealing with hardwood areas, and especi- 

 ally shade-bearing hardwoods, it is often a good plan to 

 leave all the suppressed trees, provided they be healthy ; for 

 they will shade the soil, help to preserve the humus, and 

 keep out the wind and sun. Beyond removing dead and 

 sickly trees, all that is necessary is to free the best-grown 

 trees from any undue competition with their neighbours, all 

 else being left 1 



An endeavour should be made to have vigorous quick- 



1 This is termed by French foresters : " Eclaircie par le haut." 



