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Sea cliffs - summary of States
Because of the nature of cliffs and their management needs two basic cliff
forms are considered in the Guide:
- 'Hard
rock' cliff slopes and cliff tops;
- 'Soft
rock' cliff slopes.
Comment: Follow the links via the individual states to identify the
values for each.
'Hard' rock cliffs-
'Hard' rock cliffs tend to have a relatively stable open vegetation (State
1) which is maintained by exposure and/or grazing. Where grazing
pressure is removed or reduced the growth of coarse grassland and scrub (State
2) can adversely effect the often rich plant communities (together
with specialist invertebrates such as the large
blue butterfly).
'Soft' rock cliffs
'Soft' rock cliffs can be highly mobile (State
1) with little or no vegetation. As the rate of erosion decreases
then mosaics of ephemeral vegetation and communities in seepage zones appear
(State 2).
As the period between episodes of instability increases the opportunities for
the development of scrub and woodland also increase until a stable (State
3) is achieved. Because of the threat to life and property many eroding
sea cliffs are 'protected' by artificial structures. These can slow down or
stop the erosion and may lead to a loss of conservation interest as the more
open communities become overgrown (State
4).
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Guidance: Although the distinction between 'hard' and 'soft' rocks
is useful there is considerable overlap between these 'soft' rock categories
and chalk and limestone and other rock types with intermediate erosion
rates.
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