42 PURE AND MIXED WOODS 



groups is the best method, while to facilitate future sale of 

 the timber, as far as possible the various groups in a block 

 of forest should consist of species which mature at the same 

 time. Thus groups of larch, spruce, Douglas fir, and Scotch 

 pine could be grown in one block, the whole to be felled at 

 say sixty or seventy years of age. 



Mixtures may be of three types, according to whether they 

 are mixtures of shade-bearers only, of light-demanders and 

 shade-bearers, or of light-demanders only. 



Of mixtures of two shade-bearers only, silver fir and spruce ; 

 silver fir and beech ; and spruce and beech are the best, but 

 they are not species which are sufficiently valuable to plant 

 on a large scale alone, though they can be used for filling in 

 gaps in existing woods. 



Mixtures of light-demanders with shade-bearers are of 

 more interest to the woodman. These mixtures can be, in 

 certain cases, formed at once by planting in alternate lines 

 when it is certain that the light-demander is the quickest 

 grower. Thus larch and beech (preferably at least one- 

 quarter should be beech), ash and beech, poplars and spruce 

 are all good, while oak and beech can be mixed thus in 

 localities where oak is the faster grower. Neither larch and 

 spruce, nor ash and spruce, are good in this form, nor is oak 

 and spruce, as the spruce takes up so much moisture from 

 the soil that the oak goes ' stagheaded ' (or dies at the top). 

 Larch and Douglas fir is a good mixture, but is best formed 

 by groups, as in alternate lines the Douglas fir will probably 

 outgrow the larch and will not get properly clear of branches. 

 The pines can be mixed alternately with beech, spruce or 

 silver fir with good results, provided the shade-bearers are 

 given some help at first by planting three or four lines to 

 one line of the pines. 



Where the light-demander is likely to be outgrown, the 

 mixture may be by groups, or, especially with oak, the light- 

 demander may first be planted pure, the shade-bearer being 



