Degeneration of Oakivood 83 



No attempt has been made in the above list to separate 

 the vegetation of woods on heavy clays from those on 

 light loams, although there are very considerable differ- 

 ences, because the data at present available are insufficient 

 to carry out such a separation satisfactorily. The woods 

 on light loams have something in common with the dry 

 oakwoods (p. 92), though the fresh moist soil distinguishes 

 them. Such plants as Anihoxanthum odoratum, Pteris 

 aquilina, Scilla Tion-scripta, Anemone nemorosa, Veronica 

 officinalis, Teucrium Scorodonia belong to these oakwoods 

 of lighter soils. 



Subordinate (Retrogressive) Associations 

 (Plate lib) 



On the edges of damp oakwoods which have been 

 carelessly exploited a scattered scrub is commonly found 

 with spaces of turf between the clumps of bushes, and an 

 occasional isolated oak-tree. This vegetation represents 

 degenerate oakwood from which the trees have nearly or 

 quite disappeared, and in accordance with the principles 

 laid down in the introduction must be reckoned as be- 

 longing to the same formation. The genetic relationship 

 of this scrub and grassland with the oakwood association 

 is quite obvious to any careful observer, and the fl eristic 

 relationship is also clear, as will be seen immediately. 



Scrub association. This may consist of any of the 

 species of the shrub-layer of the damp oakwood, but 

 Gratmgus monogyiia, Prunits spinosa, Rubus spp., Rosa spp., 

 and Uled- europseus are much the most abundant. It ^^ill 

 be noticed that all of these are spiny species, and the 

 dominance of such species is probably due to the fact that 

 they are protected by their spines from browsing animals; 

 since this kind of land is very commonly used for pasturage. 

 The bushes often form dense impenetrable clumps, which 

 appear to possess a considerable degree of permanence, 

 and, in the shelter of these, less protected shrubs often 



6—2 



