PLATE V 



((/) Zonation of plant communities on the Lancashire sand-dunes. The upper 

 parts are covered by marram [Psamiiia], the lower parts by dwarf 

 willow {Salix refens). Next comes marsh on the edge of the pond and 

 finally aquatic plants, such as Chara, under the water. In the back- 

 ground can be seen the effects of secondary erosion bv wind. 



[b) Zones of vegetation on the edge of a tarn on a peat moor in tlie English Lake 

 District. From left to right are {a) floating leaved plants (water-lily), 



[b) 'Teedswamp " of Carex mixed with floating pondweed [Potamogeton), 



[c) marsh with Carex, grading into sweet gale [Myrica] marsh, [d] 

 bracken [Pteris), or coniferous woods. 



