CHAP, viii.] Formation of Woodland Crops 159 



it may in general be accepted that soil and situation are 

 favourable for their cultivation there. But this general rule 

 is of course capable of being followed only in certain cases, 

 and need not be always acted on as, for example, when 

 a spontaneous growth of Birch or Aspen asserts itself on soil 

 from which the owner is entitled to expect better returns, and 

 a more valuable yield of timber, than in the ordinary nature 

 of things these kinds of crops can possibly promise. 



The selection of trees is, however, by no means a free one ; 

 for there are many soils and situations where it is decidedly 

 limited, or on which it is practically a case of 'Hobson's 

 choice.' Thus, on dry sandy soils, no forest tree can compete 

 with the Scots Pine, whilst on wet, sour, marshy land the 

 common Alder holds equal sway ; on peat bogs, that have 

 been drained, a mixture of Scots and Weymouth Pines and 

 Birch often offers the most advantageous crop ; on low-lying 

 tracts, liable to inundation annually, Willows and Poplars are 

 best endowed by nature for growing under these special cir- 

 cumstances ; whilst Spruce and Larch thrive in elevated 

 localities with cool, humid atmosphere, above the zone where 

 deciduous broad-leaved trees could find their natural and 

 congenial habitat. 



On many soils and situations a considerable number of 

 genera of forest trees find conditions fairly well suited to their 

 general growth ; but, in general, one or other of the physical 

 properties determines the elimination of certain kinds when 

 crops are to be formed for profitable timber-production in 

 contradistinction to ornamental growth and aesthetic effect. 

 Thus, deficiency of soil-moisture may frequently preclude the 

 idea of forming crops of Alder, Ash, Maple, Sycamore, and 

 Elm, whilst want of atmospheric humidity may militate against 

 the full normal development of Beech, Hornbeam, Spruce, 

 and even Silver Fir; or, where the soil is wanting in depth 

 and penetrability, Oak, Ash, Maples, Elm, Lime, Larch, Pines, 

 Silver and Douglas Firs cannot extend their root-systems so as 



