154 THE DEVELOPMENT OF BRITISH FORESTRY 



bearer and a light-demander — as, for instance, oak and 

 beech, larcli and beech or silver fir, or Scots pine and 

 spruce. But the vakie of such mixtures, and the results 

 produced by them, depend very largely upon the soil and 

 climate. On very thin or wet soils, or in Avet and cold 

 climates, the mixture may not prove so successful as the 

 pure crop. Underplanting of a Scots pine wood on poor 

 gravel in a cold, wet district may not produce any good 

 results, as the shade-bearer will be unable to acquire suffi- 

 cient strength and vigour to benefit the pine by soil- 

 shading and production of humus, while the preservation 

 of moisture, which would result from this humus layer, 

 would be an unnecessary advantage in most cases. Hard 

 and fast lines for the formation of cither pure or mixed 

 woods, therefore, cannot be laid down in all cases, and the 

 general conclusion that must be arrived at from a careful 

 consideration of facts is, that groups of different species, 

 either pure or in suitable mixture, are preferable to large 

 unbroken areas of either one kind or the other. 



To the British forester the mixed plantation is a familiar 

 object, whether good or bad. Occasionally larch, Scots 

 pine, and other species are planted pure, but the more 

 general practice, especially on good soil, is to put in a 

 mixture of conifers and broad-leaved trees, varying in 

 number of species from ten to twenty, according to the 

 ideas of the planter. These mixtures are usually bad, for 

 reasons which are well known to most foresters, and to 

 them may be traced almost entirely the bad quality and 

 low yields of timber complained of.^ 



The question of suitable mixtures is of the greatest 

 importance in British woodlands. An ideal mixture 

 might be regarded as composed of four constituents. 

 First, the species which will develop into the profitable 

 crop at the end of the rotation adopted. Second, the 



^ Vide English Estate Forestry. 



