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Saltmarsh stability - summary
The presence of saltmarsh is dependent on the growth and establishment of salt-tolerant
plants on tidal flats. The vegetation imparts stability to the sediment as accretion
and the process of succession
takes place. As saltmarshes grow they can also erode either in the course of
natural change due to sea level or tidal channel movements or because of human
interference. The natural (and unnatural) cycles of erosion can be used to define
three states:
- State 1
Erosional;
- State 2
Dynamic equilibrium;
- State 3
Accretional.
Guidance: These states are not mutually exclusive and a combination
of erosional and accretional forms may occur in the same site. Each state has
both positive and negative attributes. The differences are highlighted in the
descriptions of the value
of each. State 2 could be said to represent the 'desired' state where the balance
of accretion over erosion is neutral. State 1 has largely negative values; whilst
State 3 may be deemed positive for sea
defence but can have adverse implications for some conservation interests,
especially related to invasion by Spartina.
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