Introduction

On casual inspection, saltmarshes might appear dull, monotonous places. After more detailed investigation, the range of organisms which will have been encountered is very diverse. The great diversity reflects the fact that saltmarsh straddles the boundary between land and sea and provides habitats for both terrestrial and marine organisms.

In this chapter, the biota of saltmarshes is introduced, with special reference to the flora. The relatively brief treatment of the fauna does not imply that animals are unimportant components of saltmarsh ecosystems. However, the biology of the saltmarsh fauna has been reviewed by Daiber (1982), a publication to which readers are referred for a more comprehensive treatment.

The genecology of some saltmarsh vascular plants is discussed. At a time when plant physiologists are increasingly looking to saltmarshes for experimental plants and systems and ecologists are seeking generalisations about species' behaviour to feed into ecosystem models it is appropriate to emphasise that species are inherently variable and that this variability is the basis for ongoing evolution.

The flora

The vascular flora

Saltmarsh floras are small when compared with those from most other habitats but it is nevertheless difficult to compile complete floristic lists for many parts of the world. In part, this reflects lack of scientific recording from many coasts but, more fundamentally, it is due to the lack of agreement regarding the definition of saltmarsh and the constitution of its flora.