76 THE STORY OF PLANT LIFE 



Taking into account all these abnormal causes it 

 is not surprising that a large proportion of plant 

 formations in the British Isles are not natural. 

 Indeed it has been said there is no indigenous wood- 

 land. In England the percentage of natural vegeta- 

 tion is not more than 20 per cent, at the most. 

 The aquatic types of vegetation, maritime vegetation, 

 upland moorlands, heaths and Arctic Alpine forma- 

 tions include the bulk of this natural vegetation. 



Those formations that have been most largely 

 altered are woodland and the resultant grassland. 



Owing to the difference in soil in different parts 

 of the country we have primarily different types of 

 woodland. 



The type which is characteristic of clays and loams 

 is damp oakwood, made up of the pedunculate variety 

 of oak. There are in each woodland three main 

 zones or layers of vegetation, the tree zone, the 

 shrub zone, and the ground flora, which may be 

 made up of cryptogams such as mosses, if we take 

 these into account, or of low herbaceous flowering 

 plants, if we exclude the mosses and hepatics, etc. 



The woods (see Fig. 13) are of copse type with 

 standards or trees either in ope7i or close canopy , and 

 the scrub may be either close or open. The coppice 

 or scrub consists in this case often of Hazel, or 

 of young Oak, Hazel, Birch. Other shrubs are 

 Willow, Cornel, Maple, Hawthorn, various Roses 

 and Brambles. 



Such climbing plants as Honeysuckle, Ivy, etc., 



