322 ECOLOGY OF SALT MARSHES 



community 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 surv^ey of 

 our present information about the algal communities of salt 

 marshes. The principal features are set out in Table XVI, 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 future comparisons. 



Table XVI shows that there is not the same ubiquitv* of the 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 ver\- 

 different tv'pes 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 growing in a very soft mud, whilst the east coast marshes 

 bear a ver}' mixed vegetation growing on a mud that tends to be 

 clay-hke. In spite of this, however, the Sandy Chlorophyceae, 

 Muddv Chlorophyceae, Gelatinous Cyanophyceae, Rivularia- 

 Phaeococcus socies, Catenella-Bostrychia consocies and the Fucus 

 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, however, they are very often found in the 

 same phanerogamic communit^^ 



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 Vauch- 

 erietum can be distinguished dominated by V. sphaerospora, but 

 where the phanerogamic vegetation is ver\' 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 distribution, as also the Catenella-Bostrychia community, 

 whilst the pan flora appears to be richest in East Anglia. Perhaps 

 the most interesting feature is the distribution of the marsh fucoid 

 Pehetia canalicidata ecad libera which occurs in north Norfolk, 

 Lough Ine and Strangford Lough in Ireland and at Aberlady near 



