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Routes to restoring shingle structures and vegetation -
summary
State
1 (erosional) and State
2 (accretional or stable) are typically associated with shingle beaches,
which are subjected to the action of waves and storms. Movement between these
states can form part of the natural processes associated with this dynamic landform
in which plants can perform a limited role. However, the erosional state is
often the predominant form and where the shingle represents an important line
of sea defence, action to help stabilise the beach is frequently undertaken
with management aimed at moving the beach from State
1 - State 2.
The mechanisms involved can include some of the following:
The direction of movement is as shown in the Figure opposite. The preferred
direction of movement from a sea defence perspective is shown in the figure
in blue.
| General guidance: Shingle recycling may be used to help sustain
beaches. However, where material is removed then damage to the existing
structure of the beach and any vegetation will occur. Note that in a few
cases, and for the restoration of more natural shingle forms, a reversal
of the process to restore shingle movement may be considered appropriate
i.e. State
2 to State 1 by allowing natural
processes to dominate. |
State 3 and State
4 are associated with more stable beaches and structures. Here the
loss of the surface shingle is the key issue. Restoring the shingle structure
(ridges and lows) is difficult, but restoring vegetation on areas remaining
above the water table is feasible. Thus for this form of restoration the conservation
requirements are the most significant justification for action. Natural regeneration
of plant communities takes place over time and though a variety of techniques
have been tried to encourage the establishment of vegetation these are not thought
to be particularly effective. Hence moving the shingle surface form State
4 to State 3 may largely be a matter of 'leaving nature to take its
course'.
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General guidance: The route taken to restore shingle, especially
where it involves attempts to reconstruct shingle structures, must take
account of the physical
types involved.
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