Information and Advisory Note Number 107 Back to menu
1.1 The Habitats Directive
1.1.1 The Habitats Directive (Council Directive 92/43/EEC of 21 May 1992 on the
conservation of natural habitats and wild fauna and flora) came into legal force
in June 1994. The overall aim of the Directive is "to promote the maintenance of
biodiversity*. This is to be achieved by setting up a network of sites for the
protection of habitats and species. These sites will be known as "Special Areas
of Conservation" (SAC) and will be part of a network of "Nature 2000" sites.
1.1.2 The habitats are listed in Annex I of the Directive. These habitats are
considered to be under threat in the EU because they are in danger of
disappearance or have a restricted range in Europe. Habitats are also included
that present outstanding examples of one of the five biogeographical zones into
which the EU is divided. Some habitats that are considered to be in particular
danger of disappearance are given priority status (indicated by * in section 2)
under the Directive.
1.2 Scope of the Atlas
1.2.1 This Atlas deals with Annex I upland habitats (heaths, grasslands etc.)
and peatland habitats (bogs and fens) in Scotland. The maps give the known
distribution of these habitats at the scale of 10 km squares. They are therefore
to the same format as maps of NVC plant communities (Rodwell 1991a, b; 1992;
1995 and Horsfield, Thompson & Tidswell 1996) and the Atlas of the British Flora
(Perring & Walters 1962).
1.2.2 Eighty-two Annex I habitats occur in the UK as a whole, including 22
priority habitats. Of these, seven are considered to be represented by poor
examples in a European context, owing to the absence of typical species and
other characteristic features, and SAC are not proposed for them (Brown et al
1997, Buck & Wright 1995).
1.2.3 Forty-seven Annex I habitats occur in Scotland (Scottish Natural Heritage
1995), of which 24 are represented in the uplands (excluding woodland, but
including scrub) or are peatland habitats. All of the upland and peatland
habitats are treat in this note, and distribution maps are provided for 19 of
these. Five habitats which are known to occur in Scotland are not mapped because
there is a lack of information about their distribution. The distribution of
Active raised bogs and Degraded raised bogs are combined on the same map, to
give 18 maps in total. Notes on the known distribution and related NVC types of
unmapped habitats are given in section 2. There is one fen habitat (Calcareous
fens with Cladium mariscus and species of the Caricion davalliana) included,
whose status in Scotland has yet to be established.
1.3 CORINE and the National Vegetation Classification
1.3.1 Annex I habitats are based on CORINE (Devillers et al 1991), a
classification that has been little used in Britain. The CORINE lists biotopes
or broad habitats, which are differentiated by the growth form of the vegetation
and ecosystem functions. These broad habitats encompass a range of vegetation
types differentiated by species composition. The vegetation types are arranged
hierarchically so for example Dry heaths include Sub-montane Vaccinium
heaths and Sub-Atlantic Calluna-Genista heaths each with a series of sub-types,
some of which are further sub-divided. Individual Annex I habitats are located
within CORINE at different levels within the hierarchy and so may encompass a
broader or narrower range of constituent vegetation types.
1.3.2 The standard classification of upland and peatland vegetation types in
Britain is the National Vegetation Classification (NVC) (Rodwell 1991a, b; 1992
& 1995). The distribution maps of Annex I habitats are based on NVC distribution
maps after the range of NVC types encompassed by each Annex I habitat was
determined. To determine the NVC types relevant to each habitat reference was
made to CORINE and the Interpretation manual of European Union habitats
(European Commission DGXI 1996). In general our interpretation was checked with
the Joint Nature Conservation Committee cross-comparison between Annex I
habitats and NVC (JNCC 1997). Reasons for any differences in interpretation are
given in the text. Since the majority of habitats encompass more than one NVC
type most of the maps are based on the combined distribution of one or more NVC
types. There are three exceptions. The combined map of 51.1 *Active raised bogs
& 51.2 Degraded raised bogs is based on an inventory of raised bogs (Lindsay &
Immirzi 1996) while the maps of Calaminarian grasslands and limestone pavement
are based on the known distributions of the habitats.
1.4 Sources of information
1.4.1 The habitat distribution maps incorporate information from published NVC
maps (Rodwell 1991a, b; 1992,1995) updated by Horsfield, Thompson & Tidswell
(1996) from the NCC Upland Survey Project (Hobbs & Sydes 1988), and SNH survey
work (e.g. Quarmby, Everingham & Reid 1996).
1.4.2 The maps are based on incomplete knowledge of the distribution of
habitats, and many gaps remain. They are intended as a general guide to the
distribution of upland and peatland Annex I habitats and provide updated and
additional maps for Scotland of the provisional Atlas for the UK of Buck &
Wright (1995).
1.5 Note on the maps
1.5.1 10 km square records of most Annex i habitats are given as either solid
black circles
or open circles (lowland squares). Underlying the habitat distribution map are
the grey circles of a 10 km square map showing the combined distribution of 13
upland land classes developed by ITE (Bunce & Barr 1988). The size of the grey
circle indicates the number of these combined 13 upland land classes assigned to
1 km squares as a proportion of all 1 km squares within each 10 km square. Hence
the underlying grey map shows the distribution and relative extent of the
uplands within each 10 km square.
1.6 Upland and lowland distributions
1.6.1 Some habitats occur both in the uplands and the lowlands. Where the
information is available, and for completeness, the distribution of the habitat
both in the uplands and the lowlands is shown. Where both solid and open circles
appear on a map the black circles represent records where upland land classes
are recorded. Open circles are from squares that only have lowland land classes
recorded. The presence of only black circles on the map indicates that there are
no records from purely lowland squares except in the case of maps for 51.1
'Active raised bogs & 51.2 Degraded raised bogs (combined map) and 52.1-52.2
Blanket bog ("active only), where no distinction has been made between upland
and lowland squares.
2.1 The CORINE reference number for each Annex I habitat is given in
parentheses. The NVC types used to compile the maps for each habitat are listed.
2.2 Temperate heath and scrub
2.2.1 (31.11) Northern Atlantic wet heaths with Erica tetralix
The map shows the combined distribution of the following NVC types:
M15 Scirpus cespitosus-Erica tetralix wet
heath
M16 Erica tetralix-Sphagnum compactum wet
heath
H5 (Erica vagans-Schoenus nigricans heath) of the JNCC (1997) list is restricted
to England. M14 Schoenus nigricans-Narthecium ossifragum mire is also included
by JNCC (1997). This is a local community in western Scotland with only three
records
(Wheeler & Shaw 1995) but may have a wider occurrence. Wet heath is widely
distributed in the uplands, though it is more frequent and extensive in the
north and west.
2.2.2 (31.2) Dry heaths (all sub-types)
The map shows the combined distribution of the following NVC types:
H7 Calluna vulgaris-Scilla vema heath
H10 Calluna vulgaris-Erica cinerea heath
H12 Calluna vulgaris-Vaccinium myrtillus
heath
H16 Calluna vulgaris-Arctostaphylos uva-usi
heath
H18 Vaccinium myrtillus-Deschampsia
flexuosa heath
H21 Calluna vulgaris-Vaccinium myrtillus-
Sphagnum capiliifolium heath
H1 to H4 inclusive (JNCC 1997) are restricted to England. No data was
incorporated for H8 Calluna vulgaris-Ulex gallii heath and H9 Calluna vulgaris-Deschampsia
flexuosa heath which are recorded locally in Scotland. H8 occurs in south-west
Scotland and H9 is known from a few sites in Angus and Perthshire (Lynne Farrell
pers. comm.). Dry heaths are widespread in the uplands and they also occur
widely along the coast, especially in the west and north, including the Moray
Firth. There are relatively few records from 10 km squares without upland
ground, based on the ITE land classes, but there are undoubtedly gaps in
coverage of lowland heaths.
2.2.3 (31.4) Alpine and subalpine heaths
The map shows the combined distribution of the following NVC types:
H13 Calluna vulgaris-Cladonia arbuscula
heath
H14 Calluna vulgaris-Racomitrium
lanuginosum heath
H15 Calluna vulgaris-Juniperus communis
nana heath
H17 Calluna vulgaris-Arctostaphylos alpina
heath
H19 Vaccinium myrtillus-Cladonia arbuscula
heath
H20 Vaccinium myrtillus-Racomitrium
lanuginosum heath
H22 Vaccinium myrtillus-Rubus
chamaemorus heath
Alpine and subalpine heaths are largely restricted to high or exposed ground in
the
Highlands and Islands but also occur locally in the Southern Uplands on some of
the highest ground.
2.2.4 (31.622) Sub-Arctic willow scrub
The map mainly shows the distribution of the following NVC type:
W20 Salix lapponum-Luzula sylvatica scrub
The floristically related Salix myrsinities scrub, known only from Inchnadamph,
is also included. Sub-Arctic willow scrub is practically confined to the
Highlands, mainly the Grampians. There is a fragment on the Moffat Hills in the
Southern Uplands (not shown).
2.3 Sclerophyllous scrub (Matorral)
2.3.1 (31.88) Juniperus communis formations on heaths or calcareous grasslands
The map shows the distribution of the following NVC type:
W19 Juniperus communis ssp. communis-Oxalis acetosella woodland.
The greatest concentration of juniper scrub is in the eastern Highlands, mainly
on Speyside and Deeside. There are outliers to the north and in the Southern
Uplands.
2.4 Natural and semi-natural grassland
formations
2.4.1 (34.2) Calaminarian grasslands
The map shows known sites for Calaminarian grasslands.
The following NVC type belongs to this kind of grassland:
OV37 Festuca ovina-Minuartia vema community
The habitat is highly disjunct, occurring on the Lendalfoot Hills in Ayrshire,
the eastern Highlands, Rum and Shetland.
2.4.2 (35.1) *Species-rich Nardus grasslands,
on siliceous substrates in mountain areas (and
submountain areas, in continental Europe)
The map shows the combined distribution of the following NVC types
CG10 Festuca ovina-Agrostis capillaris-Thymus praecox grassland
CG11 Festuca
ovina-Agrostis capillaris-Alchemilla alpina grass-heath
These grasslands are widely distributed in the uplands and their main
concentrations are in the Grampians, western Highlands and Inner Hebrides.
2.4.3 (37.31) Molinia meadows on chalk and
clay (Eu-Molinion)
The related NVC types are:
M24 Molinia caerulea-Cirsium dissectum fen-meadow
M26 Molinia caerulea-Crepis paludosa mire
M24 is not considered to occur in
Scotland (Cooper & MacKintosh 1996). M26 occurs locally, for example on the Whitlaw Mosses in Roxburghshire. A map of the UK distribution is provided by
Buck & Wright (1995).
2.4.4 (36.32) Siliceous alpine and boreal
grassland
The map shows the combined distribution of the following NVC types:
U7 Nardus stricta-Carex bigelowii grass-heath
U8 Carex bigelowii-Polytrichum alpinum sedge-heath
U9 Juncus trifidus-Racomitrium lanuginosum rush-heath
U10 Carex bigelowii-Racomitrium lanuginosum moss-heath
U11, U12 and U14 are included in this habitat by JNCC (1997). In CORINE they are
assigned to another habitat. On the ground they are usually closely associated
with Siliceous alpine and boreal grassland on hills exceeding about 900 m in
altitude in the Highlands. The habitat is widely distributed in the Highlands
and Islands, and also occurs locally in the Southern Uplands.
2.4.5 (36.41 to 36.45) Alpine calcareous
grassland
The map shows the combined distribution of the following NVC types:
CG 12 Festuca ovina-Alchemilla alpina-Silene
acaulis dwarf-herb community
CG13 Dryas octopetala-Carex flacca heath
CG14 Dryas octopetala-Silene acaulis ledge community
The habitat occurs widely in the Grampians, western Highlands and in the Inner
Hebrides.
2.4.6 (37.7 and 37.8) Eutrophic tall herbs
The map shows the distribution of the relevant sub-communities (Rodwell 1992) of
the following NVC type:
U17 Luzula sylvatica-Geum rivale tall-herb community
This habitat occurs mainly in the Highlands, but is recorded locally on the
islands and in the eastern Southern Uplands.
2.5 Raised bogs and mires and fens
2.5.1 (51.1) *Active raised bogs and (51.2) Degraded raised bogs (still capable
of natural regeneration)
The map shows the distribution of the raised bog sites given by Lindsay &
Immirzi (1996).
The related NVC types include the following:
*Active raised bogs
M1 Sphagnum auriculatum bog-pool
community
M3 Eriophorum angustifolium bog-pool
community
M18 Erica tetralix-Sphagnum papillosum
raised and blanket mire
M20a Eriophorum vaginatum blanket and
raised mire, species-poor sub-community
Degraded raised bogs
M1 Sphagnum auriculatum bog-pool
community
M2 Sphagnum cuspidatum/recurvum bog
pool community
M3 Eriophorum angustifolium bog-pool
community
M15 Scirpus cespitosus-Erica tetralix wet
heath
M16 Erica tetralix-Sphagnum compactum wet
heath
M17 Scirpus cespitosus-Eriophorum
vaginatum blanket mire
M18 Erica tetralix-Sphagnum papillosum
raised and blanket mire
M20 Eriophorum vaginatum blanket and
raised mire
M25 Molinia caerulea-Potentilla erecta mire
Raised bogs occur chiefly in the lowlands while blanket bog takes over as the
main ombrogenous bog in the uplands.
2.5.2 (52.1 and 52.2) Blanket bog (*active
only) The map shows the combined
distribution of the following NVC types:
M1 Sphagnum auriculatum bog-pool
community
M15 Scirpus cespitosus-Erica tetralix wet
heath
M17 Scirpus cespitosus-Eriophorum
vaginatum blanket mire
M18 Erica tetralix-Sphagnum papillosum
raised and blanket mire
M19 Calluna vulgaris-Eriophorum vaginatum
blanket mire
M20 Eriophorum vaginatum blanket and
raised mire
The above NVC list corresponding to blanket bog includes fewer NVC types than
that of the most recent JNCC list (JNCC 1997) which has been recently expanded
to include the same list as for Degraded raised bogs. However, the map is
considered to provide a good coverage of the distribution of blanket bog.
Blanket bog is almost ubiquitous in the uplands but records are lacking from
some of the upland fringes, mainly in the east and south.
2.5.3 (54.12) *Petrifying springs with tufa
formation (Cratoneurion)
Information on this habitat is incomplete. The map shows the combined recorded
distribution of the following NVC types:
M37 Cratoneuron commutatum/filicinum-Festuca rubra spring
M38 Cratoneuron commutatum-Carex nigra
spring
The known distribution of the habitat is patchy and is mainly from Atholl, the
Breadalbanes, the western Grampians, the North-west Highlands, and there are
outliers on some of the islands and in the Southern Uplands.
2.5.4 (54.2) Alkaline fens
The map shows the combined distribution of
the following NVC types:
M9 Carex rostrata-Calliergon cuspidatum/
giganteum mire
M10 Carex dioica-Pinguicula vulgaris m i re
M11 Carex demissa-Saxifraga aizoides mire
Both Schoenus nigricans-Juncus subnodulosus mire (M13) and Schoenus
nigricans-Narthecium ossifragum mire (M14) are included in this habitat by JNCC
(1997). Both are lowland communities which are only known locally from Scotland.
There is a record of M13 from Islay (Wheeler & Shaw 1995). Floristically M14
belongs to Northern Atlantic wet heaths (Wheeler 1995). Alkaline fens are
widespread in the uplands, though they are infrequently recorded in some areas.
2.5.5 (54.3) *Alpine pioneer formations of
Caricion bicoloris-atrofuscae
The map shows the combined distribution of the following NVC types:
M11 Carex demissa-Saxifraga aizoides mire
M12 Carex saxatilis mire
Stands of M10 Carex-Pinguicula mire with arctic-alpine species characteristic of
the habitat may belong to this type, but generally M10 belongs to (54.2)
Alkaline fens. Although conforming to the NVC types some recorded stands may
lack the characteristic arctic-alpine species. Because of this the true
distribution is likely to be more restricted than the map shows. This habitat is
mainly developed in the Highlands while there are scattered occurrences
elsewhere.
2.5.6 (54.5) Transition mires and quaking
bogs
The map shows the combined distribution of the following NVC types:
M4 Carex rostrata-Sphagnum recurvum
mire
M5 Carex rostrata-Sphagnum squarrosum
mire
M8 Carex rostrata-Sphagnum warnstorfii
mire
M9 Carex rostrata-Calliergon cuspidatum/
giganteum mire
S27 Carex rostrata-Potentilla palustre fen
These mires are scattered widely across much of the uplands and upland fringes.
There are concentrations in the Breadalbanes and Skye.
2.5.7 (54.6) Depressions on peat substrates
(Rhynchosporion)
The Rhynchosporion develops on exposed peat or sand within some of the areas of
peatland supporting the following NVC type
M16 Erica tetralix-Sphagnum compactum
mire
M18 Erica tetralix-Sphagnum papillosum
raised and blanket mire
M21 Narthecium ossifragum-Sphagnum
papillosum valley mire
The data for this habitat are incomplete and are not mapped. The only SAC that
have been proposed are in southern and eastern England. A map showing two key
sites for this habitat is provided by Buck & Wright (1995).
2.5.8 (53.3) *Calcareous fens with Cladium mariscus and species of the Caricion
davallianae
The related NVC types are:
S2 Cladium mariscus swamp and sedge-beds
S24 Phragmites australis-Peucedanum palustre tall-herb fen
S25 Phragmites australis-Eupatorium cannabinum tall-herb fen
M9 Carex rostrata-Calliergon cuspidatum/
giganteum mire
M13 Schoenus nigricans-Juncus
subnodulosus mire
M24 Molinia caerulea-Cirsium dissectum fen
meadow
The presence of this calcareous fen in Scotland is not definitely established.
Since most of the above NVC fen types and Cladium mariscus are present it may
occur. Buck & Wright (1995) provide a map of the key sites, which are in England
and Wales.
2.6 Rocky habitats and caves
2.6.1 (61.1) Siliceous scree
The map shows the combined distribution of the following NVC types:
U18 Cryptogramma crispa-Athyrium distentifolium snow-bed
U21 Cryptogramma
crispa-Deschampsia flexuosa community
An alternative map is provided by Buck & Wright (1995) showing the distribution
of the fern Cryptogramma crispa which grows in acid soils in rocky places in the
uplands but is not always present in siliceous scree. C. crispa occurs widely in
the uplands though it is absent from the far north and west of Scotland,
including many of the islands.
Siliceous scree without C. crispa occurs in which the plant communities are made
up predominately of bryophytes and lichens. Known occurrences of the associated
NVC communities with C. crispa are mainly in western Scotland, the Cairngorms
and in the Southern Uplands. The habitat is likely to occur in many other areas.
2.6.2 (61.2) Eutric scree
Information on this habitat is incomplete and no map is provided.
The following NVC type is associated with base-rich scree:
OV38 Arrhenatherum elatius-Geranium robertianum community
2.6.3 (62.1 and 62.1A) Chasmophytic
vegetation on rocky slopes, calcareous sub
types and (62.2) Chasmophytic vegetation on
rocky slopes, silicicolous sub-types
Inadequate information is available to provide maps of these chasmophytic rock
habitats. Most crags provide at least some crevices for chasmophytic plant
species and since crags are widespread in the uplands some form of the habitat
will be of widespread occurrence.
2.6.4 (62.4) *Limestone pavements
The map shows the known distribution of limestone pavement rock formations based
on a list provided by Dr Stephen Ward (pers. comm.) compiled from field surveys
by a range of workers.
Though a wide range of NVC types are associated with this habitat, none are
exclusive to it. Limestone pavement is of local occurrence in Scotland being
developed on Durness limestone in the NW Highlands at Durness, Inchnadamph,
Rassal and on Skye; and on Dalradian limestone at a number sites in Argyll &
Bute and Perth & Kinross.
Brown, A.E., Bum, A.J., Hopkins, J.J. & Way, S.F. (1997). The Habitats
Directive: selection of Special Areas of Conservation in the UK. JNCC Report No.
270, Peterborough.
Buck, A. L. & Wright, J. (1995). EC Habitats Directive: a provisional atlas of
Annex I habitats and Annex II species. JNCC Report No. 241, Peterborough.
Bunce, R.G.H. & Barr, C.J. (1988). The extent of land under different management
regimes in the uplands and the potential for change. In Ecological Change in the
Uplands. Ed. by M.B. Usher & D.B.A. Thompson, pp. 415-426 . Blackwell Scientific
Publications, Oxford.
Cooper, E. & MacKintosh, J. (1996). NVC review of Scottish grassland surveys.
Scottish Natural Heritage Review. No. 65, Battleby.
Devillers, P., Devillers-Terschuren, J. & Ledant, J.-P. (1991). CORINE Biotopes
Manual Habitats of the European Community Data Specifications - Part 2.
Commission of the European Communities, Luxembourg.
European Commission DGXI (1996). Interpretation manual of European Union
habitats: version EUR 15. Brussels, European Commission DGXI.
Hobbs, A. & Sydes, C. (1988). The Upland Vegetation Survey. Unpublished report.
NCC, Edinburgh.
Horsfield, D., Thompson, D.B.A. & Tidswell, R. (1996). Revised atlas of upland
NVC plant communities in Scotland. Information & Advisory Note No. 56. Scottish
Natural Heritage, Battleby.
JNCC (1997). Relationship between Annex I habitats and National Vegetation
Classification communities. Unpublished report. JNCC, Peterborough.
Lindsay, R. A. & Immirzi, C. P. (1996). An inventory of lowland raised bogs in
Great Britain. Scottish Natural Heritage Research, Survey and Monitoring Report
No. 78, Battleby.
Perring, F.H. & Walters, S.M. (1962). Atlas of the British Flora. Thomas Nelson
& Sons, London.
Quarmby, N.A., Everingham, F. & Reid, E. (1996). A satellite map representation
of the blanket mires of Lewis (satellite scene 208/19) Scottish Blanket Bog
Satellite Project. Unpublished report to Scottish Natural Heritage, Edinburgh.
Rodwell, J.S. (1991a). British Plant Communities Vol. 1 Woodlands and Scrub.
Cambridge University Press, Cambridge.
Rodwell, J.S. (1991b). Bntish Plant Communities Vol. 2 Mires and Heaths.
Cambridge University Press, Cambridge.
Rodwell, J.S. (1992). British Plant Communities Vol. 3 Grasslands and Montane
Communities. Cambridge University Press, Cambridge.
Rodwell, J.S. (1995). British Plant Communities Vol. 4 Aquatic Communities,
Swamps and Tall-herb Fens. Cambridge University Press, Cambridge.
Scottish Natural Heritage (1995). Natura 2000 A Guide to the 1992 EC Habitats
Directive in Scotland's Terrestrial Environment. SNH, Battleby.
Wheeler, B.D. (1995). Fen Habitats and the EC Habitats and Species Directive
Part 1 Concept and Compass of Selected Fen Habitat Categories. Unpublished
report to JNCC, Peterborough.
Wheeler, B.D. & Shaw, S.C. (1995). Fen Habitats and the EC Habitats and Species
Directive Part 2 Distribution and Status of Selected Fen Habitats in Britain.
Unpublished report to JNCC, Peterborough.
We thank the following for comments or advice: Prof. H.J.B. Birks, Dr Andrew Coupar, Dr John Hopkins, Mr Richard Lindsay, Dr Derek Ratcliffe, Ms Eliane Reid, Prof. John Rodwell and Dr Stephen Ward. We acknowledge the efforts of the NCC/SNH 'Upland Survey' teams in providing many of the more recent upland vegetation records.
D Horsfield and DBA Thompson
Advisory Services
Scottish Natural H
EDINBURGH
EH6 5NP
Tel: 0131-447 4784
R J Tidswell
124 West Drive
CLEVELEYS
Lancashire
FY5 2JG
