Jncc coastal Directories Project Region 11 The Western Approaches

B.  Further reading
Bottrell, H.H., & Robins, D.B.  1984.  Seasonal variations in length,
dry weight, carbon and nitrogen of Calanus helgolandicus from
the Celtic Sea.  Marine Ecology Progress Series, 14: 259-268.
Collins, N.R., & Williams, R.  1982.  Zooplankton communities in
the Bristol Channel and Severn Estuary.  Marine Ecology Progress
Series, 9: 1-11.
Head, P.C.  1975.  Bibliography of estuarine research.  The Natural
Environment Research Council Publication Series C, No. 17.
Joint, I.R.  1984.  The microbial ecology of the Bristol Channel.
Marine Pollution Bulletin, 15: 62-66.
Pingree, R.D., & Griffiths, D.K.  1978.  Tidal fronts on the shelf seas
around the British Isles.  Journal of Geophysical Research, 83:
4,615-4,622.
Simpson, J.H.  1976.  A boundary front in the summer regime of the
Celtic Sea.  Estuarine, Coastal and Marine Science, 4: 71-81.
Williams, R.  1984.  Zooplankton of the Bristol Channel and Severn
Estuary.  Marine Pollution Bulletin, 15: 66-70.
Williams, R., & Collins, N.R.  1984.  Distribution and variability in
abundance of Schistomysis spiritus (Crustacea: Mysidacea) in the
Bristol Channel in relation to environmental variables, with
comments on other mysids.  Marine Biology, 80: 197-206.
Williams, R., & Collins, N.R.  1985.  Chaetognaths and ctenophores
in the holoplankton of the Bristol Channel.  Marine Biology, 85:
97-105.
Williams, R., & Conway, D.V.P.  1980.  Vertical distribution of
Calanus finmarchicus and C. helgolandicus (Crustacea: Copepoda).
Marine Biology, 60: 57-61.
Williams, R., & Fragopoulu, N.  1985.  Vertical distribution and
nocturnal migrations of Nyctiphanes couchi (Crustacea:
Euphausiacea) in relation to the summer thermocline in the
Celtic Sea.  Marine Biology, 89: 257-262.
C.  Contact names and addresses
Type of information
Contact address and telephone no.
Continuous Plankton
Director, Sir Alister Hardy
Recorder (CPR) survey data
Foundation for Ocean Science,
The Laboratory, Citadel Hill,
Plymouth  PL1 2PB,
tel: [phone]
Plankton research
Head of Department, Department
of Oceanography, Southampton
University, University Road,
Southampton  SO9 5NH,
tel: [phone] ext. 3642
Bristol Channel data
Director, Plymouth Marine
Laboratory, Prospect Place,
The Hoe, Plymouth  PL1 3DH,
tel: [phone]
Ichthyoplankton
*MAFF DFR, Fisheries Laboratory,
Lowestoft, tel: [phone]
Lundy plankton
The Warden, Lundy, Bristol
Channel, via Bideford, Devon
EX39 2LY, tel: [phone]
*Starred contact addresses are given in full in the Appendix.
Region 11  Chapter 4  Marine and estuarine environments
78
Woods in Region 11 resemble a subtropical rainforest in the lushness of their vegetation.  Because of the mild, moist climate and unpolluted
atmosphere, they host a rich array of bryophytes, lichens and other lower plants, including slime moulds.  Some parkland trees are swathed
in warmth-loving epiphytic lichens, such as those pictured here at the Dizzard, Cornwall.  Photo: Pat Doody, JNCC.

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5.1.1  Introduction
This section covers lichens, bryophytes (mosses and
liverworts), stoneworts (a group of freshwater and brackish
algae - the latter are covered in 
section 5.4
) and fungi
occurring in the coastal 10 km squares of the region.  This
region is of considerable importance for lower plants,
especially those that have an oceanic, Lusitanian or
Mediterranean-Atlantic distribution pattern.  Many of the
lower plants found in the region are not known elsewhere in
Britain, being at the northern limit of their European range,
and many also have a very restricted international
distribution.  About 51% of the British bryophyte flora and
about 48% of the stonewort flora occur in the region.
Similar figures are not available for other groups, but a high
percentage of the lichen and fungus floras can be expected,
because of the oceanic climate and the great variety of
habitats.
A number of the region’s habitats are particularly
favoured by lower plants.  The Cornish coast, especially on
the Lizard peninsula, is one of the richest stretches of cliff
and cliff-top coastline in Britain for lichens and bryophytes.
In addition the region’s dune systems are particularly rich in
liverworts and fungi.  Coastal ravine woodlands in the
region contain a distinctive range of oceanic species,
particularly slime moulds.  The Isles of Scilly form a unique
lower plant locality and an outpost for many Lusitanian
species at the edge of their range.  
5.1.2  Important locations and species
Table 5.1.1
lists all the sites in the region that are known to
be important for lower plants and that have had at least
some degree of survey work.  Many are large, in which case
the grid reference given refers to a reasonably central point.
Most of the sites were selected for conservation on the basis
of their bryophyte and lichen interest.  Many of the sites
contain rare and scarce species and qualify for Site of Special
Scientific Interest (SSSI) status on the basis of their lower
plant flora (Hodgetts 1992).  There are notably few
important sites for lower plants in the south Wales part of
the region.  Locations are shown on 
Map 5.1.1
.
Like higher plants, lower plant species tend to occur in
characteristic assemblages that are found in particular
habitats.  Lichens are particularly well represented on cliff
rocks, while skeletal soils on cliff-tops harbour unique
bryophyte communities.  Coastal hard rock cliffs and cliff-
top grassland and heath, for example, support some of the
most distinctive south-western species assemblages.  In
particular, the Lizard peninsula, where the substrate rock is
serpentinite, is of great importance, with several species
79
Chapter 5  Important species
5.1  Terrestrial lower plants
N.G. Hodgetts
85
80
75
70
65
60
55
54
87
50
45
40
35
30
25
24
5
1
15
20
10
5°W
Region 10
Region 12
Map 5.1.1  
Sites (in coastal 10 km squares) known to be important
for lower plants.  Site numbers refer to those in
Table 5.1.1.  Source: JNCC Red Data Book database.
having their only British occurrences here.  More unstable
cliffs can also be important for lower plants, as at Saunton
Down in Devon.  There is a distinctive, and threatened,
community of both lower and higher plants that occurs only
in wheel ruts and other bare hollows on heathland on the
Lizard.  There are also important dune systems in Devon
and Cornwall, although they are relatively small.  Some
dune sites support good populations of the liverwort
Petalophyllum ralfsii and the lichen Fulgensia fulgens, along
with several other species virtually restricted to this habitat.
Braunton Burrows in particular is rich in fungi, with
141 species recorded.  Many of the fungi on sand dunes are
mycorrhizal with (depend on a close association with the
root systems of) higher plants, with willow and marram
grass apparently being important associates.
Old mine workings and china clay quarries are a
characteristically Cornish landscape feature supporting a
unique and specialised lower plant flora.  Some bryophytes
and lichens are specialists of soils that are rich in heavy
metals, and these species may be virtually confined to spoil
tips of old lead and copper mines.  Woodland on the fringes
of Exmoor and sheltered wooded ravines in Cornwall and
Devon are important for their oceanic bryophytes, lichens
and fungi, particularly myxomycetes (slime moulds).  Many
oceanic species (most notably small liverworts of the family
Lejeuneaceae) are confined to this habitat.  Fungi are
important as wood decomposers.  The species composition
of woods in the region tends to be slightly different from
that of woods further north, with a greater preponderance
of warmth-loving species.  The trees in some parklands in
the region support a good epiphytic lichen flora.  
There are several lower plant species that occur only on
the Isles of Scilly, apart from on the Lizard.  Important

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