CHAP, vi.] Advantages of Mixed Woods 119 



a mixed crop than to look after one species only ; but when weighed 

 against the many solid advantages offered by mixed crops, this drawback 

 can surely seldom be seriously taken into account.' 



Mixed woods are such as are formed by two or more species, 

 of which the matrix or ruling species should be one that is 

 capable of safeguarding and retaining the productive capacity 

 of the soil against insolation and the exhausting action of 

 winds. The subordinate or dependent species of trees may 

 be admixed with the ruling species either in dumps or hursts \ 

 in groups or clusters, in patches or knots, in rows or lines, or 

 merely scattered about singly as individuals. In mixed woods, 

 wherever natural regeneration is permitted to the fullest extent, 

 there will 'be a tendency for genera of trees with heavy seeds 

 (Oak, Beech, and among Conifers the Silver Fir) to reproduce 

 themselves in clumps on the patches of soil best suited to 

 them ; whilst trees with lighter and often winged seeds (like 

 Birch, Aspen, and Willow) will have a much greater repro- 

 ductive power of asserting themselves individually and in 

 small knots at some distance from the parent trees. 



i. A greater Density of Crop is obtainable. Wherever the 

 area under woodlands is of any considerable extent there are 

 almost certain to be many variations of soil and situation with 

 regard to the nature and the depth of the earth, its degree of 

 moisture, its aspect, &c. ; and the best, most complete, and 

 most economical utilization of the soil can only be expected 

 when each such varying portion is stocked with the species of 

 tree best suited for growing there. For, when thus growing in 

 admixture on the patches of soil most suitable to their natural 

 requirements, it will be found that the various species of trees 

 do not thin themselves so soon as they otherwise must on soils 

 less favourable to their natural development and requirements. 

 And, by thus maintaining close canopy for the longest possible 

 period, they not only avail themselves more fully of the pro- 



1 The older term Base, often referred to by Manwood (History of the 

 Forest Laws), is now obsolete. 



