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Key
Sites
Nearly a tenth of the Region's land area is designated as nationally
and internationally important wildlife sites , many of which are
unique in Europe. The maritime environment is particularly significant
in the South West as the ratio of coastline to land area is the
highest of any region. At a more local level, areas of wildlife
value may be designated as local nature reserves, county wildlife
sites or non-statutory nature reserves.
Species
The South West supports some 25 species that are globally important,
over 700 species that are of national conservation concern, and
34 species endemic to the UK, 11 of which are only found in the
South West, such as lundy cabbage, western ramping fumitory and
cornish path moss. 70 % of the UK population of greater horseshoe
bats occur in the South West and over 25% of the national population
of nightjar. For South West England the farmland bird population
index shows a 44% decline over 30 years from 1970 to 2000. The shallow
reefs off the coast of east Devon and Dorset support high densities
of the pink sea fan - a soft coral more typical of Mediterranean
waters.
Habitats
The South West supports a high proportion of some of the UKs rarest
and most endangered habitats. Many are UK priority habitats . These
include:
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Calcareous grassland - 62 % of the UK total
- e.g. Salisbury Plain, Wiltshire
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Lowland heathland - 25 % of the UK total
- e.g. Dorset heathlands.
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Flower rich pastures - 57 % of the UK total
- e.g. Culm grasslands, Somerset Levels and Moors
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Saline lagoons - 37 % of the UK total -
e.g. The Fleet, Dorset is the largest brackish lagoon in England
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Offshore reefs - e.g. those off south and
east Devon are among the best in the country
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Ancient Semi - Natural Woodland - 20% of England's
total
Many of these, especially soft coastal habitats
(e.g. Bridgwater Bay saltmarshes or Slapton Ley saline lagoon),
floodplain marshes (e.g. Somerset Levels and Moors), and chalk rivers
(e.g. the River Avon) have been identified as particularly vulnerable
to climate change (DETR/MAFF 2000).
Terrestrial
and Freshwater Habitats
Notable habitats in the South West include upland moorland, lowland
wet grassland, chalk rivers, estuaries and the dramatic and varied
coastline.
Many habitats are under threat and their areas declining. These
include the calcareous grasslands to the east of
the Region, fens and marshes on Dartmoor and Exmoor,
and neutral and acidic grassland to the west of
the Region. Much of this is being replaced by improved grassland
(west) and arable or horticultural uses (east) (all information
DETR/CEH, 2000).
The South West has a relatively high proportion of woodland habitats
compared to the rest of England and our woodlands are extremely
diverse. Habitats that are particularly important to the Region
are upland oak woodlands, upland ash woodlands, wet woodlands
and wood pasture & parkland (RPG Public Examination,
2000).11 woodland areas are candidate SACs, including South Dartmoor
Woods (upland ash and upland oak), Avon Gorge Woodlands (lime-ash
ravine forest) and Salisbury Plain (lowland juniper scrub) (English
Nature, 1999).
The Region supports a number of internationally important rivers,
streams and wetlands. Chalk rivers, such as the
Rivers Kennet, Avon and Frome, predominate in parts of the Region.
Elsewhere, rivers are characterised as clay-bottomed (e.g. Thames
and Avon Vales), upland (e.g. on Dartmoor and Bodmin Moor) or limestone/sandstone
(e.g. the Wye) (English Nature, 1999).
Wetlands include the open floodplain of the River
Avon (Wilts, Dorset, Hants), the wet grasslands of the Somerset
Levels and Moors, the Exe Estuary, and less well known areas such
as the Culm grasslands of Devon and north Cornwall.
These grasslands are important to marsh fritillary butterflies,
plants such as whorled caraway and heath spotted orchid.
The continued existence of all these wetlands depends on a delicate
blend of poorly drained land, winter flooding and traditional grazing
by cattle. Wetlands are not only havens for wildlife. They also
play an important role in the water cycle. By retaining water for
long periods, they absorb nutrients, ameliorate flooding and assist
the percolation of rainwater into aquifers. Increasing the area
of wetlands in the Region would be of considerable benefit to our
river systems. Maintaining these wetlands is a delicate balance,
and will become more complex in the future due to the impacts of
climate change.
[ref: SW Regional Observatory Website http://www.swenvo.org.uk]
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