Biodiversity & Conservation

To assess the sensitivity of the biotope, the sensitivity of component species is reviewed. Those species that are considered to be particularly indicative of the sensitivity of the biotope, and for which research has been undertaken in detail are shown below (see selection criteria). The biology of other component species of the biotope is also taken into account wherever information is known to the researcher.

• Puccinellia maritima
• Glaux maritima
• Limonium vulgare
• Armeria maritima
• Plantago maritima
• Aster tripolium
• Salicornia spp.

• Salicornia pusilla
• Spartina maritima
• Suaeda vera

Puccinellia maritima is the dominant halophyte in this biotope, however it may only represent <10% of the sward in the Limonium vulgare-Aremaria maritima sub-communities. It is, therefore, regarded as a constant, important characterizing species for the purpose of assessment. Most other invertebrate species (marine or terrestrial) are not directly associated with the community and could probably survive in its absence within another plant community. Grazers and plant feeding insects probably affect reproductive output of plants and primary productivity. Similarly, grazers (including birds) and detritivores are important for nutrient cycling within the biotope. However, many species are involved and vary with shore height and salinity so that it is difficult to identify any particular species for sensitivity assessment. Therefore, a general assessment has been undertaken.

Puccinellia maritima dominated communities are generally regarded as species poor habitats (Rodwell, 2000). However, this statement generally refers to the vascular plant communities alone. The dynamic and heterogeneous salt marsh habits and their plant communities support a diverse array of marine and terrestrial invertebrates, microalgae, cyanobacteria, fungi, fish, birds and in some cases mammals (including livestock). For examples of species found in saltmarsh habitats refer to reviews by Long & Mason (1983), Adam (1993) and Packham & Willis (1997) and the references therein. Floristic table for Puccinellia maritima sub-communities are given by Rodwell (2000)
Saltmarsh habitats support a number of rare or scarce plant species, together with some UK BAP species e.g. the ground beetles Arnara strenua and Anisodactylus poeciloides. This biotope may contain the British Red Data Book species, Limonium bellidifolium (Wigginton, 1999).