184 Sub-formation of Marls and Calcareous Sa/ndstones 



EXPLANATION OP SYMBOLS 



° Querous Eobur A Salix cinerea 



" Fraxiuus excelsior -i Viburnum Opulus 



^ \ Corylus Avellana i^ V. Lantana 



^^ Acer campestre ^ Betula spp, 



'^ Populus tremula j)ar. villosa T = Pyrus torminalis 



Fig. 6. Chart of the trees and shrubs of part of Gamlingay wood, 

 Cambs., showing an island of the dry oakwood association (on 

 sandy loam) enclosed within Ash-oak-hazel wood fon calcareous 

 boulder-clay). 



