ECOLOGY OF SALT MARSHES 347 



munity by another as the marsh increases in height provides 

 changes that are more akin to those that are found in land habitats. 

 With this in mind the present author recently attempted a survey 

 of our present information about the algal communities of salt 

 marshes. The principal features are set out in Table lo, and it will 

 be observed that in the suggested nomenclature the ordinary 

 ecological terminations for developing seres has been employed. 

 Whether this is entirely justified in view of the present somewhat 

 scanty knowledge may perhaps be questioned, but it is possible 

 that if the nomenclature can be placed on a proper basis at an early 

 stage it should facilitate further comparisons. 



Table lo shows that there is not quite the same ubiquity of com- 

 munities in the different areas that can be found on a rocky coast. 

 The reason for this is probably to be associated with the very dif- 

 ferent types of salt marsh that can be found. For example, the Irish 

 marshes are composed of a form of marine peat, the marshes on the 

 west coast of England have a large sand component in the soil, the 

 marshes on the south coast bear a tall vegetation of Spartina grow- 

 ing in a very soft mud, whilst the east coast marshes bear a very 

 mixed vegetation growing on a mud that tends to be clay-like. In 

 New England the marshes are formed of a marine peat whilst in 

 New Zealand the soil is either a muddy or sandy clay. In spite of 

 this, however, the Sandy Chlorophyceae, Muddy Chlorophyceae, 

 Gelatinous Cyanophyceae, Rivularia-Phaeococcus socies, Catenella- 

 Bostrychia consocies and the Fuciis limicola consocies all have a 

 wide distribution though they may not necessarily appear at the 

 same relative levels on the different marshes. On the whole, how- 

 ever, they are very often found in the same phanerogamic com- 

 munity. 



A comprehensive tour of the salt marshes of England will show us 

 that one or more of the communities described above occur in all 

 the different districts. Where the soil is rather sandy a Vaucherietimi 

 can be distinguished dominated by V. sphaerospora, but where the 

 phanerogamic vegetation is very dense or heavily grazed by animals 

 the algal vegetation is poor, e.g. south and west coast marshes. The 

 Sandy Chlorophyceae and Vaucheria thuretii have a wide distribu- 

 tion, as also the Catenella-Bostrychia community, whilst the pan 

 flora appears to be richest in East Anglia. Perhaps the most inter- 

 esting feature is the distribution of the marsh fucoid Pelvetia canali- 

 culata ecad libera which occurs in north Norfolk, Lough Ine and 



