Pre-marsh processes • Zonation & succession
Abiotic Factors • Dynamics & Decline

Pre-marsh processes

In several estuaries, particularly on more sandy substrates, there appears to be no absolute preconditions for the growth of colonising vascular plants and the subsequent development of saltmarsh, other than the amelioration of the hazardous physical and chemical forces associated with tidal submergence.

Most saltmarsh plants are essentially terrestrial organisms variously adapted to, or tolerant of, a semi-marine environment. At a minimum, they require sunlight and an atmosphere for photosynthesis and growth and, to acquire nutrients, their roots must be bathed in non-toxic solutions of ionic concentrations low enough to enable absorption by osmosis. All of these basic conditions are violated at some time by the act of tidal submergence.

Saltmarsh plants have evolved various ways of coping with this factor and, in fact, very few (if any) British saltmarsh species require seawater at all in order to survive. Salt-tolerant plants are 'halophytes', therefore, it can be said that there are no saltmarsh obligate halophytes. On the contrary, provided that they are kept free of weeds, most saltmarsh plants can flourish in ordinary garden soils. In tolerating saline conditions, saltmarsh plants can out-compete other terrestrial vegetation.

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