248 Studies in Forestry [CHAP. XL 



and on moister localities the Hornbeam, are on the whole 

 preferable to Spruces or other Firs, for they accommodate them- 

 selves more to the natural habits of growth of the standards. 

 But; on the other hand, for Larch and Pine woods, though 

 Spruces, or on the better classes of soil and in mild sunny 

 situations Silver Firs, naturally conform more to the habits 

 and development of coniferous standards, an underwood of 

 Beech or Hornbeam is distinctly preferable when the con- 

 ditions of soil and situation permit of it, owing to the great 

 advantages conferred by them in respect of decreasing the 

 dangers arising from insect enemies and fungoid parasites. 

 In this matter the effect of the underplanting resembles the 

 advantages gained by an admixture of broad-leaved species 

 with the conifers ; and the benefits become more pronounced as 

 the underwood grows up nearer the level of the crowns of the 

 standards. Very often, however, the choice of the species to 

 be used for underplanting depends mainly on the nature of 

 the soil and situation, and is practically limited to the four 

 great shade-bearing genera, Beech, Hornbeam, Spruce and 

 Silver Fir leaving out of consideration such exceptional 

 cases as favour coppice-growth of Alder under essentially light- 

 demanding species on moist, fertile, rather marshy soils. 

 Among exotics of comparatively recent introduction Nord- 

 mann's Fir seems best endowed with the requisite shade- 

 bearing and soil-improving capacity. If the Douglas Fir also 

 prove suitable, the timber of the latter holds out very enticing 

 financial promises to far-seeing landowners. 



Of these genera, Spruce is the one which makes most 

 moderate demands as to the quality of the soil; while it has 

 also the advantage of confining them to the upper layer of soil 

 through which the root-systems of deeper-rooted trees like Oak 

 and Pine do not ramify. The other shade-bearing genera not 

 only make greater demands for nutrients, but also tend to com- 

 pete with the standard trees in extracting them from the deeper 

 layers of soil. Speaking practically, Beech and Hornbeam 



