Ash-oak-hazel Copse 183 



practically all the other trees, as well as the various shrubs, 

 are coppiced. Hazel is generally the dominant shrub in 

 such coppice, and in many cases gaps are filled up with 

 planted hazel. In this way the wood conies to resemble 

 superficially the oak-hazel copse derived from damp oak- 

 wood. It is only by noting the abundance of ash in the 

 coppice and the variety and abundance of shrubs other 

 than the hazel, as well as the presence of calcicole species 

 in the ground vegetation, that the wood can be assigned 

 to its proper type (Figs. 6 and 7). 



Another factor tending to the assimilation of the oak- 

 hazel copses derived respectively from the ash-oakwood 

 and from the damp oakwood is the frequent poverty in 

 lime of the surface soil of the former to a depth of some 

 inches, probably due to leaching. This, with the accumu- 

 lation of humus,, leads to the establishment on the floor of 

 the wood of shallow-rooting plants not found on soils rich 

 in lime. The more deeply-rooting plants, therefore, such 

 as the shrubs, are often a better index than the her- 

 baceous species of the essential character of these woods. 



Oak-hazel woods of the type described are well 

 developed on the Triassic and Jurassic marls of Somerset 

 and on the chalky boulder-clay of Cambridgeshire. 

 They have been described by Moss' and by Adamson^ 

 respectively, to whose memoirs the reader is referred for 

 lists of species. Adamson has also studied in some detail 

 the ecological conditions determining the occurrence of 

 different sub-associations of the ground vegetation. 



The ash-oakwoods on calcareous sandstones and sandy 

 limestones have not been described, but so far as they 

 have been investigated they show similar intermediate 



1 Moss, 1907, pp. 51 — 56. These woods are described byMoss simply as 

 "oak-hazel woods"; they certainly belong to the ash-oakwood association, 

 an association which has since been recognised. See Moss, Eankin and 

 Tansley, 1910, p. 138. 



2 Adamson, 1911. 



