NATIONAL VEGETATION CLASSIFICATION field guide to mires and heaths National Vegetation Classification: Field guide to mires and heaths Cover photograph: Studland Heath National Nature Reserve, Dorset. © English Nature National Vegetation Classification: Field guide to mires and heaths T. Elkington, N. Dayton, D.L. Jackson and I.M. Strachan Joint Nature Conservation Committee Monkstone House City Road Peterborough PE1 1JY UK ISBN 1 86107 526 X © JNCC 2001 Contents

1. Introduction 7 National Vegetation Classification 7 Mires and heaths: scope of this guide 7 Using this guide 7 References 8 2. Dendrogram keys to mire communities 9 3. Mire community descriptions and sub-community keys 19 M1 Sphagnum auriculatum bog pool community 19 M2 Sphagnum cuspidatum/recurvum bog pool community 20 M3 Eriophorum angustifolium bog pool community 21 M4 Carex rostrata – Sphagnum recurvum mire 22 M5 Carex rostrata – Sphagnum squarrosum mire 23 M6 Carex echinata – Sphagnum recurvum/auriculatum mire 24 M7 Carex curta – Sphagnum russowii mire 26 M8 Carex rostrata – Sphagnum warnstorfii mire 27 M9 Carex rostrata – Calliergon cuspidatum/giganteum mire 28 M10 Carex dioica – Pinguicula vulgaris mire 30 M11 Carex demissa – Saxifraga aizoides mire 32 M12 Carex saxatilis mire 33 M13 Schoenus nigricans – Juncus subnodulosus mire 34 M14 Schoenus nigricans – Narthecium ossifragum mire 34 M15 Scirpus cespitosus – Erica tetralix wet heath 36 M16 Erica tetralix – Sphagnum compactum wet heath 38 M17 Scirpus cespitosus – Eriophorum vaginatum blanket mire 40 M18 Erica tetralix – Sphagnum papillosum raised & blanket mire 42 M19 Calluna vulgaris – Eriophorum vaginatum blanket mire 44 M20 Eriophorum vaginatum blanket & raised mire 46 M21 Narthecium ossifragum – Sphagnum papillosum valley mire 47 M22 Juncus subnodulosus – Cirsium palustre fen-meadow 48 M23 Juncus effusus/acutiflorus – Galium palustre rush-pasture 50 M24 Molinia caerulea – Cirsium dissectum fen-meadow 52 M25 Molinia caerulea – Potentilla erecta mire 54 M26 Molinia caerulea – Crepis paludosa mire 56 M27 Filipendula ulmaria – Angelica sylvestris mire 58 M28 Iris pseudacorus – Filipendula ulmaria mire 60 M29 Hypericum elodes – Potamogeton polygonifolius soakway 62 M30 Related vegetation of seasonally inundated habitats 62 M31 Anthelia julacea – Sphagnum auriculatum spring 63 M32 Philonotis fontana – Saxifraga stellaris spring 64

5 M33 Pohlia wahlenbergii var. glacialis spring 66 M34 Carex demissa – Koenigia islandica flush 66 M35 Ranunculus omiophyllus – Montia fontana rill 67 M36 Lowland springs and streambanks of shaded situations 67 M37 Cratoneuron commutatum – Festuca rubra spring 68 M38 Cratoneuron commutatum – Carex nigra spring 69 4. Dendrogram keys to heath communities 70 5. Heath community descriptions and sub-community keys 76 H1 Calluna vulgaris – Festuca ovina heath 76 H2 Calluna vulgaris – Ulex minor heath 78 H3 Ulex minor – Agrostis curtisii heath 80 H4 Ulex gallii – Agrostis curtisii heath 82 H5 Erica vagans – Schoenus nigricans heath 84 H6 Erica vagans – Ulex europaeus heath 86 H7 Calluna vulgaris – Scilla verna heath 88 H8 Calluna vulgaris – Ulex gallii heath 90 H9 Calluna vulgaris – Deschampsia flexuosa heath 92 H10 Calluna vulgaris – Erica cinerea heath 94 H11 Calluna vulgaris – Carex arenaria heath 96 H12 Calluna vulgaris – Vaccinium myrtillus heath 98 H13 Calluna vulgaris – Cladonia arbuscula heath 100 H14 Calluna vulgaris – Racomitrium lanuginosum heath 102 H15 Calluna vulgaris – Juniperus communis ssp. nana heath 104 H16 Calluna vulgaris – Arctostaphylos uva-ursi heath 104 H17 Calluna vulgaris – Arctostaphylos alpinus heath 106 H18 Vaccinium myrtillus – Deschampsia flexuosa heath 108 H19 Vaccinium myrtillus – Cladonia arbuscula heath 110 H20 Vaccinium myrtillus – Racomitrium lanuginosum heath 112 H21 Calluna vulgaris – Vaccinium myrtillus – Sphagnum capillifolium heath 114 H22 Vaccinium myrtillus – Rubus chamaemorus heath 116

6 1 Introduction

National Vegetation Classification dune slack communities and Epilobium hirsutum stands are described in Volume 5 (Rodwell 2000). Since its development in the 1980s, the National ‘Grass heaths’, Dryas heaths and related lichen Vegetation Classification (NVC) has become the and bryophyte dominated vegetation are included standard classification used for describing vegeta- in Volume 3 (Rodwell 1992), as are certain wet tion in Britain. Whereas many other classifications grasslands. Volume 1 (Rodwell 1991b) encompasses are restricted to particular types of vegetation, the wet woodland and scrub vegetation. Companion NVC aims to describe all the vegetation of Great guides to volumes 1 and 3 have also been pub- Britain. This means that it is possible to analyse, lished by JNCC (Hall et al. 2001; Cooper 1997). and map, a complex site, composed of several Users of this guide should also note that most habitat types (e.g. woodland, scrub, heathland and ‘wet heath’ vegetation is described in the NVC bog) using the same classification system. with the mires rather than the heaths (as M15 The NVC is a ‘phytosociological’ classification, Scirpus cespitosus – Erica tetralix wet heath and classifying vegetation solely on the basis of the M16 Erica tetralix – Sphagnum compactum wet plant species of which it is composed. The result- heath), because of its floristic affinities. Helpful ing communities can usually be correlated to other insight into the floristic relationships of NVC factors, such as geology and soils, climate, water types can be gained from the Phytosociological chemistry and management; but the plant species Conspectus in Volume 5 of British Plant alone are used to assign the vegetation to a Communities. This places all NVC communities community. within a hierarchical framework of European The NVC breaks down each broad vegetation vegetation. type (e.g. heath, mire, woodland) into communities, Various gaps in coverage of the NVC have been designated by a number and name (e.g. H4 Ulex gal- identified at community and sub-community level lii – Agrostis curtisii heath, M10 Carex dioica – subsequent to the publication of British Plant Pinguicula vulgaris mire, W4 Betula pubescens – Communities. These include several mire and Molinia caerulea woodland). Many (but not all) of heath types, as outlined in JNCC Report No. 302 these communities contain two or more sub-com- Review of coverage of the National Vegetation munities, designated by a letter (e.g. H4b Ulex gal- Classification (Rodwell et al. 2000). No attempt lii – Agrostis curtisii heath, Festuca ovina sub-com- has been made to incorporate these here, pending munity). Sub-communities in a few cases are fur- further analysis and formal description. ther divided into variants (e.g. M10bi and ii).

Mires and heaths: Using this guide scope of this guide The summary descriptions provided here are The second volume of British Plant Communities derived directly from the full accounts prepared was published in 1991 (Rodwell 1991a). It provides by John Rodwell, but are in no way a substitute for a detailed account of 38 mire communities and 22 them. Rather they are intended as an aide-mem- heath communities, giving information on their oire to assist surveyors in the field or for anyone composition, structure and distribution, their else wishing to familiarise themselves with the affinities to other types of vegetation, both in overall scheme of classification for mires and Britain and on the Continent, and the relation of heaths. Anyone who uses this book should always the communities described within the NVC to check their results against the frequency tables those previously described by other authors. The and full descriptions for each community in scope of this field guide is identical to that of Volume 2 of British Plant Communities. The Volume 2. descriptions are not intended to take account of A number of vegetation types which might also the results of recent survey work undertaken by be considered as ‘mires’ or ‘heaths’ are described the three country agencies (Countryside Council in other volumes of British Plant Communities, for Wales, English Nature, Scottish Natural and so are not included here. Aquatic, swamp and Heritage) which may help circumscribe some of tall-herb fen communities can be found in Volume the communities more tightly and improve our 4 (Rodwell 1995), whilst inundation communities, understanding of community distributions.

7 A series of dendrograms have been produced to References show the broad floristic relationships between the main communities and between the sub-commu- nities for each community where these exist. Cooper, E A (1997) Summary descriptions of Nat- These dendrograms are only intended as guides ional Vegetation Classification grassland and and should not be followed slavishly. Details of montane communities. Joint Nature Con- variants, if indicated, can be found in Volume 2 of servation Committee, Peterborough (UK Nature British Plant Communities. Conservation No. 14). The amount of any particular species is Hall, J E, Kirby, K J and Whitbread, A M (2001) referred to both in terms of its frequency and National Vegetation Classification: field guide abundance. ‘Frequency’ refers to how often a plant to woodland. Joint Nature Conservation Com- is found in moving from one sample or vegetation mittee, Peterborough. to the next, irrespective of how much of that Rodwell, J S, (ed) (1991a) British Plant Commun- species is present in each sample. This is sum- ities. Volume 2. Mires and heaths. Cambridge marised in the published tables as classes denoted University Press, Cambridge. by the Roman numerals I to V: 1-20% frequency Rodwell, J S, (ed) (1991b) British Plant Commun- (that is, up to one sample in five) = I, 21-40% = II, ities. Volume 1. Woodlands and scrub. Cambridge 41-60% = III, 61-80% = IV, and 81-100% = V. The University Press, Cambridge. summary descriptions follow the usual conven- Rodwell, J S, (ed) (1992) British Plant Commun- tion of referring to species of frequency classes IV ities. Volume 3. Grasslands and montane com- and V in a particular community as its constants, munities. Cambridge University Press, Cambridge. with those species of class III as common or fre- Rodwell, J S, (ed) (1995) British Plant Commun- quent, of class II as occasional and of class I as ities. Volume 4. Aquatic communities, swamps scarce or rare. The term ‘abundance’, on the other and tall-herb fens. Cambridge University Press, hand, is used to describe how much of a plant is Cambridge. present in a sample, irrespective of how frequent Rodwell, J S, (ed) (2000) British Plant Commun- or rare it is among the samples. It is summarised ities. Volume 5. Maritime communities and in the published tables as bracketed numbers for vegetation of open habitats. Cambridge the Domin ranges, and is referred to in the text University Press, Cambridge. here, as in the published descriptions, using such Rodwell, J S, Dring, J C, Averis, A B G, Proctor, M terms as dominant, abundant, frequent and sparse. C F, Malloch, A J C, Schaminée, J N J and The nomenclature for plant species used in Dargie, T C D (2000) Review of coverage of the British Plant Communities has been followed in National Vegetation Classification. JNCC Report this publication for consistency. Botanists more No. 302. familiar with Stace’s New flora of the British Isles Stace, C (1997) New flora of the British Isles. 2nd (Stace 1997) may not recognise names such as ed. Cambridge University Press, Cambridge. (Stace equivalent in brackets): Scirpus cespitosus (Trichophorum cespitosum), Carex demissa (C. viridula ssp. oedocarpa), C. lepidocarpa (C. viridula ssp. brachyrrhyncha) and Silene vul- garis maritima (S. uniflora). Amongst cryptogams, the common lichen of heaths and bogs referred to here as Cladonia impexa is now generally known as C. portentosa.

8 2 Dendrogram keys to mire communities spp., See Fig 9. 9a. Tall rushes, 9a. Tall Juncus and/or tall fen herbs dominant. Molinia caerulea rare but may be locally abundant in western mires. Schoenus . See Fig 8. 8a. Sedges may be frequent in the sward but not dominant and never structurally important. Molinia caerulea nigricans 9. constant and usually structurally important in the vegetation; with or without Carex See Fig 7. 7a. More bulky vegetation in which sedges, rushes, grasses or tall herbs are prominent. spp. not Eriophorum 8. Vegetation dominated by sedges, or spp., either in open mats low, more or taller, dense mires. , nent. Sphagnum , Pohlia See Fig 6. , 1a. constant in the vegetation. Occasional small patches may be present but these are never prominent. Koenigia or commutatum can be promi can be 6a. Open bryophyte mats around springs. Sphagnum auriculatum can be constant. See Fig 6. wahlenbergii Philonotis fontana Anthelia julacea islandica 7. Spring or flush vegeta- tion; an open bryophyte- rich mat in which any of: Cratoneuron . . See Fig 5. 6. Semi- aquatic rills and flushes dominated by Potamogeton polygonifolius and/or Montia fontana 5a. Open springs or rills with constant, but patchy Sphagnum auriculatum with S. cuspi- semi- See Fig 4. other vascular vascular species typically sparse. Bog pools. 5. Mossy carpet dominated by aquatic Sphagnum spp., includ- ing datum 3a. Sedges may be present but are subordinate to bryophytes or to species. See Fig 3. 4a. Vege- tation domi- nated by other sedges or tall rushes. , . and/or spp. Calluna spp., or E. See Fig 2. tall rushes Juncus 3. Dominated by sedges Eriophorum Carex 2a. Sub-shrubs not constant; though vulgaris Erica tetralix may be present at low abundance. spp. 4. Vegetation 4. Vegetation dominated by Eriophorum angustifolium and/or vaginatum Calluna Sphagnum See Fig 1. A Key to mires 2. vulgaris and/or Erica tetralix constant. Usually quite exten- sive mires over peat. 1. constant or very frequent in the vegetation, either continuous or patchy.

9 Mires Figure 1

Fig 1. Key to vegetation with constant Sphagnum spp. and constant ericoid sub-shrubs

1. Eriophorum vaginatum 1a. See next page (either as prominent tussocks or sparse fronds) and/or Sphagnum papillosum and/ or S. magellanicum constant. Deep peat > 1 m. Blanket and raised mires.

2. Molinia caerulea 2a. Scirpus cespitosus and/or Scirpus cespitosus not constant and rarely constant with at least prominent, though can some: Narthecium be frequent in patches. ossifragum, Eriophorum Molinia caerulea angustifolium, Potentilla generally absent (can erecta, Sphagnum form mosaics with tus- papillosum and socky Eriophorum vagi- S. capillifolium. natum in degraded forms of M19.)

3. Sphagnum spp. 3a. Sphagnum spp. patchy, prominent, especially though S. capillifolium S. papillosum, S. capilli- constant. S. tenellum, folium and S. tenellum, S. magellanicum and often S. magellanicum. Odontoschisma sphagni Associates include at generally absent or very rare. least some of Vaccinium oxycoccos, Drosera rotundifolia and 4. Calluna vulgaris and 4a. Vegetation dominated Odontoschisma sphagni. Eriophorum vaginatum form by tussocks of Eriophorum the bulk of the vegetation, vaginatum with Calluna E. vaginatum usually tus- vulgaris and Sphagnum socky, with Sphagnum capil- spp. at best infrequent lifolium, E. angustifolium and patchy. Mounds of and pleurocarpous mosses: Empetrum nigrum and/or Pleurozium schreberi, Vaccinium myrtillus with Hylocomium splendens constant Eriophorum and Hypnum jutlandicum. angustifolium and Deschampsia flexuosa.

M17 Scirpus cespitosus – M18 Erica tetralix – M19 Calluna vulgaris – M20b Eriophorum Eriophorum vaginatum Sphagnum papillosum Eriophorum vaginatum vaginatum blanket and blanket mire raised and blanket mire blanket mire raised mire, Calluna vulgaris – Cladonia spp. sub-community

Burning can increase the The Eriophorum mire proportion of Calluna is apparently biotically vulgaris or Deschampsia derived from M19 blanket flexuosa and Vaccinium bog or M18 raised mire; myrtillus. Grazing usually the degree of floristic decreases the abundance of impoverishment depend- C. vulgaris, ultimately to its ing on the intensity and disappearance, especially if duration of destructive combined with large-scale management practice. burns. Such disturbance can There is therefore a con- shift the floristics of this tinuous gradation between community towards the richer and poorer stands. impoverished M20 mire. In the wet north-west Lower altitude stands some Sphagnum spp. (<400 m) to the west usually can persist even in include constant Erica tetral- highly degraded stands, ix which is replaced in high- especially S. recurvum er and more eastern stands which is relatively toler- by Empetrum nigrum and ant to some disturbance. Rubus chamaemorus.

10 From previous page: 1a. Both Eriophorum vaginatum and Sphagnum papillosum generally absent, though may be patchily present at low frequency in the wetter sub- communities of the M15 Erica – Scirpus mire.

5. Calluna vulgaris and Erica 5a. Erica tetralix constant. tetralix both prominent with Calluna vulgaris absent or Eriophorum angustifolium present at low frequency in and Molinia caerulea constant. the vegetation.

6. Narthecium ossifragum 6a. Narthecium constant and abundant ossifragum present at with Drosera rotundifolia, low frequency. Ericoid Eriophorum angustifolium, sub-shrubs and at least Sphagnum papillosum, one of Scirpus cespitosus, plus S. auriculatum and/ Molinia caerulea and or S. recurvum. Schoenus Eriophorum angustifolium nigricans absent or make up the bulk of the very rare. vegetation over patchy sphagna, S. capillifolium or S. compactum. Wet heaths.

7. Erica tetralix usually 7a. Calluna vulgaris usu- 8. Schoenus 8a. Molinia the most prominent ally the most prominent nigricans caerulea sub-shrub. Sphagnum sub-shrub except where constant with dominant, dense layer dominated by grazing pressure has prominent and tussocky. S. compactum and favoured the expansion Narthecium Sparse Erica S. tenellum. Molinia of E. tetralix. Sphagnum ossifragum tetralix and caerulea usually domi- spp. dominated by and Sphagnum Potentilla nant amongst the vascu- S. capillifolium and subnitens. erecta constant. lar monocot associates. S. subnitens with Sphagnum occasional S. papillosum palustre and in the wetter S. recurvum can sub-communities. be prominent in wet north- western stands.

M21 Narthecium M16 Erica tetralix – M15 Scirpus cespitosus – M14 Schoenus M25a Molinia ossifragum – Sphagnum Sphagnum compactum Erica tetralix wet heath nigricans – caerulea – papillosum valley mire wet heath Narthecium Potentilla ossifragum erecta mire, May be confused with the Wet heath primarily of This is a very variable mire Erica tetralix flushed wet heath, M15a; the south and east of vegetation type and, of sub-community however the sedges Britain, this community the major components, Carex panicea, C. echinata provides the major locus any can be dominant with Burning and are constant in the latter for Scirpus cespitosus up to two of the others grazing of M15 and Myrica gale is more and Eriophorum missing. A community wet heath can frequent. Pinguicula vul- vaginatum (though rare) primarily of north-west favour an garis is common in M15a in this part of the Britain, it includes most increase in but is replaced in the country. of the heather-dominated Molinia which M21 community by less vegetation intermediate in shifts the frequent P. lusitanica. character between the dry vegetation heath and blanket mire towards that of types. Where heavily the Erica tetralix grazed and/or burnt, the sub-community ericoids can become very of M25. The sparse and these stands similarities are often transitional to between M25a the Molinia-dominated and Molinia- community M25, or rich M15 show drier stands to the Juncus the transition squarrosus grassland U6. between these two communities through distur- bance.

11 Mires Figure 2

Fig 2. Key to vegetation with constant Sphagnum spp. and dominated by Eriophorum vaginatum and/or E. angustifolium

1. Vegetation dominated by 1a. Vegetation dominated by Eriophorum angustifolium in Eriophorum vaginatum in which Sphagnum cuspidatum which E. angustifolium and/or Drepanocladus fluitans can be constant but is can be prominent. Bog pools always subordinate to and erosion hagg runnels with- E. vaginatum. in blanket peat. 2. Tussocky E. vaginatum 2a. It can be difficult to with very patchy Sphagnum separate richer forms of the capillifolium, constant M20b sub-community from Deschampsia flexuosa poor and degraded stands of and mounds of Vaccinium the M19 blanket mire, since myrtillus and/or Empetrum there is a continuum of nigrum nigrum. Calluna vegetation types between vulgaris usually absent but these two communities with can be present as scattered increasing disturbance to the sprigs at low frequency. latter. Generally, if C. vulgaris North-western stands also is constant with a reasonably feature prominent Poly- intact Sphagnum flora this trichum commune. community can be categorised with the M19 mires, though E. vaginatum may be visually dominant.

M3 Eriophorum M20b Eriophorum vagina- M19 Calluna vulgaris – angustifolium bog pool tum blanket and raised mire, Eriophorum vaginatum Calluna vulgaris – Cladonia blanket mire spp. sub-community This community is typical of recent or disturbed bog pools or forms an early seral stage in the transition from exposed peat back to mire vegetation. Poorer stands of the M2b Sphagnum recurvum bog pool can be very similar to Sphagnum-rich M3 stands, reflecting the transitional continuum between these communities.

12 Mires Figure 3 , – . – – absent sub- mire, Erio- Carex Eriophorum , can be Juncus S.recurvum C. panicea constant and and Carex nigra Carex echinata Juncus squarrosus Carex echinata J. squarrosus Carex curta S. auriculatum squarrosus very frequent in some stands. C. nigra angustifolium. Nardus stricta Nardus stricta community or very rare. echinata over a moss layer dominated by Sphagnum palustre and either or Other sedges frequent including Sphagnum recurvum/ auriculatum M6a sub-community and M6b phorum angustifolium and may be transitional to wetter forms of the U6 Festuca ovina grassland. 5a. M6 Stands with abundant Carex nigra mire Carex iola – with con- V , Eriophorum S. papillosum. , , and 1100 m asl in Sphagnum russowii Carex curta Carex curta palustris M7 Sphagnum russowii echinata angustifolium 4a. Tall rushes absent or 4a. Tall only very sparse and patchy. dominated 5. Vegetation by stant and at least two of Montane flush vegetation, almost always between 650 m central Scotland. , and – iola or Juncus absent or V , Carex echinata Juncus effusus over a moss J. acutiflorus mire, M6c sub-community Juncus acutiflorus S. recurvum Carex echinata Carex rostrata palustris layer dominated by Sphagnum palustre either S. auriculatum. 4. Vegetation dominated by 4. Vegetation tall rushes; and/or usually with but this sometimes very sparse. Associates include: Polytrichum commune Potentilla erecta 1a. present only at low frequency. Sphagnum recurvum/auric- ulatum effusus and M6d sub-community M6 , , mire , – Epilobium iola palustris , V , Selaginella Sphagnum teres. , and Carex rostrata Sphagnum warnstorfii Carex nigra Aulacomnium palustre Calliergon cuspidatum Rhizomnium pseudopuncta- tum M8 Sphagnum warnstorfii Montane flush vegetation, almost always between m400 and 800 m asl. 3a. constant with at least three of palustre selaginoides mire , spp. and dominated by sedges or tall rushes – spp. Succisa , Eriophorum , dominated com- Aulacomnium , Sphagnum Sphagnum Carex rostrata Sphagnum recurvum Potentilla palustris Sphagnum squarrosum palustre. pratensis M5 Sphagnum squarrosum Flush or floating raft over liquid peat. Often forms stage in the transition to open water or as part of a complex mosaic with other C. rostrata munities (M9, S9, S27). angustifolium 3. constant with at least three of: Carex nigra 2a. absent or can be present but is always subordinate to other , , mire – never constant and S. squarrosum. Carex can be abundant in Carex rostrata S. warnstorfii Sphagnum recurvum Carex rostrata Sphagnum recurvum M4 Fig 3. Key to communities with constant 1. and prominent. Polytrichum commune S. cuspidatum never curta some stands (DOMIN 2-9) but 2. Moss layer dominated by present.

13 Mires Figure 4

Fig 4. Key to bog pools dominated by open Sphagnum carpets

1. Bog pool dominated by 1a. Bog pool dominated by Sphagnum auriculatum and Sphagnum cuspidatum and/or S. cuspidatum, usually with S. recurvum. S. auriculatum some Menyanthes trifoliata never present. Scattered and Eriophorum angustifolium. Eriophorum angustifolium throughout pool; Erica tetralix, Drosera rotundifolia and other vascular species around margins.

M1 Sphagnum auriculatum M2 Sphagnum cuspidatum bog pool /recurvum bog pool

As temporary pools infill, Eriophorum angustifolium increases in prominence. Such pools can exist in all transition- al stages between M2 and M3 bog pool floristics.

Mires Figure 5

Fig 5. Key to semi-aquatic rills and flushes dominated by Potamogeton polygonifolius and/or Montia fontana

1. Flush vegetation dominated 1a. Rills and spring-head by Potamogeton polygonifolius vegetation dominated by Montia with Hypericum elodes, Ranun- fontana and Ranunculus omio- culus flammula and Juncus phyllus, usually with Ranun- bulbosus. culus flammula and some of: Juncus bulbosus, J. articulatus, Potamogeton polygonifolius, Myosotis secunda and Agrostis stolonifera.

M29 Hypericum elodes – M35 Ranunculus omiophyllus – Potamogeton polygonifolius Montia fontana rill soakway

This community has been This community has been poorly sampled from the north. poorly sampled from the north Hypericum elodes is abundant of Britain. Stands similar in in this community across south- floristics to the M35 rills but west Britain but declines to the lacking R. omiophyllus are north and is absent from most occasional along ditch-lines at stands north of the Scottish the margins of improved land Borders except for occasional in lowland areas. outliers in the Western Isles.

14 Mires Figure 6 – Carex Koenigia Saxifraga constant , and and Deschampsia Carex demissa Koenigia islandica flush stellaris Scapania undulata. M34 This community is only recorded from Ridge the Trotternish on Skye. It is described from just 4 samples. 5a. Bryophyte mat with open areas of stony ground. demissa islandica with cespitosa cespi- Pohlia Saxifraga var. glacialis. var. spring Anthelia Deschampsia Pohlia ludwigii. , Pohlia wahlenbergii and glacialis 4a. Montane springs and rills lacking julacea. Cerastium cerastoides can be frequent. tosa 5. Spongy bryophyte carpets dominated by wahlenbergii Constants include: stellaris M33 var. – with Philonotis Deschampsia and Marsupella Scapania , , and Cratoneuron Sphagnum are absent or very Anthelia julacea Anthelia julacea 1a. Montane springs or rills in which commutatum fontana sparse. 4. Open mat dominated by constant auriculatum M31 Sphagnum auriculatum spring emarginata undulata cespitosa. – fontana

P. Scapania , spring and , Cratoneuron springs, alsine Philonotis fontana Dicranella palus- Deschampsia , , Philonotis fontana Stellaria Cratoneuron commutatum , ry variable community, Sphagnum auriculatum. M32 Saxifraga stellaris Ve though presence of reliable. Lower altitude examples often lack Saxifraga stellaris grade into the commutatum M37, M38. cespitosa tris 2a. absent or only present at low frequency. constant with two or more of: Saxifraga stellaris undulata rare to Cardamine Festuca Cratoneuron with – Festuca rubra , spring Cratoneuron Agrostis stolonifera. ypically from base-rich and 3a. Springs overwhelmingly dominated by commutatum Philonotis fontana occasional. Small sedges are scarce and the diversity of vascular plants quite poor, usually including pratensis M37 commutatum rubra T areas inaccessible to grazing as this can destroy the bryophyte mat. , , can be . and Diverse Carex C. panicea Cratoneuron , – and/or spp. are fre- Carex C. nigra spring Cratoneuron C. demissa. rifolium repens M38 Light grazing is important in keeping the mat open and maintaining diversity. commutatum nigra 1. Montane or sub-montane bryophyte-rich spring-heads dominated by 2. Moss carpet dominated by Cratoneuron commutatum or occasionally by C. filicinum. 3. Species-rich springs in which commutatum Philonotis fontana and quent, though sparse, espe- cially herbs including some of: Cardamine pratensis frequent in the moss carpet. Fig 6. Key to open, bryophyte-rich springs and flushes Polygonum viviparum. Philonotis fontana Leontodon autumnalis T

15 Mires Figure 7 – and con- C. pan- may be , may at low C. lepidocarpa Saxifraga C. pulicaris Carex dioica , icea C. lepidocarpa stant. aizoides frequency. 5a. Two or more of 5a. Two Carex dioica M10 Pinguicula vulgaris mire Carex dioica absent or difficult to find in poorer stands. C. demissa replace in higher altitude/less base-rich stands. , , Aneura – constant. , mire C. pulicaris Selaginella , and Campylium , Carex demissa Carex demissa Carex saxatilis Saxifraga aizoides pinguis stellatum selaginoides. Drepanocladus revolvens Pinguicula vulgaris 4a. absent. Frequent species: Carex panicea 5. and Saxifraga aizoides M11 , , , , mire , dominant, C. demissa , C. saxatilis Drepanocladus , , C. lepidocarpa , Carex saxatilis Aneura pinguis. Carex saxatilis other sedges subordinate. Constants include: Thalictrum alpinum Hylocomium splendens Polygonum viviparum and C. echinata revolvens. 4. Montane flushes over 700 m asl. M12 C. dioica C. pulicaris 3a. Open vegetation dominated by short sedges including at least three of: Carex panicea spp. are absent or infrequent in the sward mire Sphagnum Calliergon – prominent Galium can be Eriophorum , Potentilla palustris spp. Menyanthes Eriophorum , , spp., in which Calliergon cuspidatum. Carex rostrata Carex Carex rostrata and trifoliata cuspidatum/giganteum palustre M9 3. in herb-rich swards over bulky mosses, often forming floating rafts. Constants include: angustifolium Often occurs in complex mosaics with M5 and the S27 swamp in which the diagnostic herbs are very though lacking the similar, moss carpet of M9. 1a. Vegetation dominated 1a. Vegetation by angustifolium constant but never dominant. Carex and Eriophorum Eriophorum vaginatum Eriophorum vaginatum M20 blanket and raised mire This community usually results from degraded blan- ket mire, M19. Species-poor, but a range of transitional M20-M19 stands occurs. 2a. dominant and usually Often extensive tussocky. mire. Carex spp; bog pool Eriophorum Eriophorum Eriophorum angustifolium Fig 7. Key to vegetation dominated by sedges, 1. Vegetation overwhelmingly dominated by 2. M3 angustifolium dominant on open eroded peat, especially around haggs. spp. never prominent.

16 Mires Figure 8 , mire Erica tetralix. Molinia caerulea Potentilla erecta Molinia caerulea Succisa pratensis Potentilla erecta 5a. and only constants in gen- erally quite poor vege- tation. Associates can include frequent Juncus acutiflorus and sparse herbs such as Cirsium palustre and/or M25 – , C. , – and at , mire Crepis aleriana dioica Carex panicea V , Carex nigra , Molinia caerulea Molinia caerulea Ranunculus acris. Juncus subnodulosus Cirsium dissectum pulicaris Succisa pratensis Filipendula ulmaria and 4a. and absent or rare. least three of: paludosa M26 Crepis paludosa 5. Rich fen with Existing records limit this community to the North Pennines and Lake District, though it may extend into the Southern Uplands. , – Erica – – , usually fen-meadow Associates aleriana dioica V J. articulatus Erica tetralix sub-community M24c. spp. are generally lacking Juncus subnodulosus Molinia caerulea Succusa pratensis. Calluna vulgaris J. inflexus. Molinia caerulea Cirsium dissectum 4. dominated fen with constant Cirsium dissectum with sometimes or include poor fen herbs, particularly and M24 This community is mainly in south and east Britain, though sedge-rich stands of M25 found in south-west Scotland and the Western Isles may resemble the Juncus acutiflorus 3a. absent or present at low frequency. may be frequent in the M25a sub-community tetralix Sphagnum – and constant wet heath Scirpus cespitosus Erica tetralix Schoenus nigricans Calluna vulgaris 3. and M15 Erica tetralix and usually abundant with Scirpus cespitosus Potentilla erecta. 1a. absent or rare, though may be locally frequent in flushed wet heath. – mire is constant and structurally important but Narthecium absent. , Anagallis , Drosera rotundifolia S. subnitens. , Schoenus nigricans Schoenus nigricans Erica tetralix Molinia caerulea M14 Narthecium ossifragum ossifragum tenella and generally some Sphagnum auriculatum and/or J. subnodulosus 2a. usually abundant with some of: , – mire Succisa and spp., Potentilla erecta , Juncus Schoenus nigricans Juncus subnodulosus Schoenus nigricans Juncus subnodulosus Fig 8. Key to vegetation in which 1. 2. M13 constant and abundant. constant, usually with other pratensis Carex panicea Calliergon cuspidatum.

17 Mires Figure 9 , J. acu- . Galium / Molinia Rumex and , and/or Galium palustre – can be locally abun- and other poor-fen Epilobium palustre with constant , Juncus effusus rush-pasture acutiflorus M23 In western Britain caerulea dant in this community. 3a. Vegetation dominated by 3a. Vegetation Juncus effusus tiflorus Mentha aquatica Ranunculus flammula palustre associates, most usually Cirsium palustre acetosa . . . – can Holcus J. Mentha fen-meadow J. articulatus Lotus uliginosus Cirsium palustre , and/or and Juncus subnodulosus Calliergon cuspidatum Filipendula ulmaria Juncus subnodulosus 3. Fen-meadow dominated by often with frequent inflexus Constants include: aquatica and 2a. be occasional to frequent but never prominent. Vegetation dominated by tall rushes usually with constant lanatus M22 Cirsium palustre – absent . mire , spp. are never prominent Filipendula ulmaria Rumex acetosa Iris pseudacorus Filipendula ulmaria aleriana officinalis or at low frequency in the sward. 1a. M27 Angelica sylvestris 2. constant and prominent with tall fen herbs including Angelica sylvestris V and Sphagnum . – spp. and tall herb dominated fens in which mire constant is often Filipendula , Juncus Poa trivialis and Iris pseudacorus Iris pseudacorus and generally dominant, usually with constant Oenanthe crocata ulmaria Fig 9. Key to 1. M28 Filipendula ulmaria Oenanthe crocata absent from stands of this community in the north and west of Scotland.

18 3 Mire community descriptions and sub-community keys

M1 Sphagnum auriculatum in flowering. Around the pool margins Molinia caerulea can extend down from the mire surface bog pool community although its cover is generally low. This community is confined to pools and wetter This bog pool community typically consists of hollows on ombrogenous and topogenous mires floating masses or soft wet carpets of Sphagnum with base-poor and oligotrophic raw peat soils in spp., mainly Sphagnum auriculatum (including the more oceanic parts of Britain. It is a widespread var. inundatum) and S. cuspidatum, with scat- component in the Scirpus cespitosus – Eriophorum tered vascular plants growing on or through them vaginatum blanket mire (M17) in the far west of or in areas of open water between. Locally, the Britain including western Scotland, parts of the bright orange-yellow S. pulchrum is conspicuous. Lake District, Wales, and the South-West Peninsula, S. recurvum is rare in contrast with the Sphagnum and the Narthecium ossifragum – Sphagnum papil- cuspidatum/recurvum bog pool community (M2). losum valley mire (M21) in south-western valley Other bryophytes are generally scarce, but mires with a high water table, particularly in the Cladopodiella fluitans is characteristic at low New Forest and Dorset. frequencies and Gymnocolea inflata can also be The wetness gives some protection to this present. vegetation where mires are grazed or burned, but The commonest vascular plants are Meny- it has been reduced on many sites by draining and anthes trifoliata and Eriophorum angustifolium cutting of the peat. It has been widely lost where which together make up a cover of less than 30%. Erico-Sphagnion communities have been con- In open water Sphagnum cover is reduced and verted to Ericion heaths or their degraded deriva- Utricularia species, usually U. minor or locally tives. Shallow peat-digging can create flooded hol- U. intermedia, are sometimes present. In shallow lows which become suitable for recolonisation by water Rhynchospora alba is characteristic, and R. Sphagnum spp., Rhynchospora alba and Drosera fusca is found occasionally in this community. spp., but such locally reconstituted stands often Narthecium ossifragum and Drosera spp., particu- lie in much-modified mire contexts. larly D. rotundifolia,are also occasionally present. In some areas Carex limosa is frequent, but is shy No sub-communities.

19 M2 Sphagnum cuspidatum/ community. There may be some sedges including Carex limosa, C. curta and C. magellanica. recurvum bog pool community The community is typically found in pools and lawns on very wet and base-poor raw peats on This community is typically dominated by soft ombrogenous and topogenous mires in the less wet carpets of Sphagnum cuspidatum or oceanic parts of Britain. Its range coincides S. recurvum, or both. S. pulchrum occurs very closely with that of the Erica tetralix – Sphagnum locally, occasionally with S. tenellum, S. magel- papillosum mire (M18) and it typically forms the lanicum or S. papillosum. Sphagnum auriculatum pool, wet hollow and lawn elements in that is rare in contrast with the Sphagnum auricula- community (and its degraded derivatives) on tum bog pool community (M1). Other bryo- lowland raised bogs, on locally raised areas phytes are scarce but Polytrichum commune or within low altitude blanket mires and in base-poor Aulacomnium palustre can form occasional basin mires. It occurs from Wales up through the patches and there may be scattered leafy hepatics. Scottish Borders and south-west Scotland with Vascular plants occur as scattered individuals some localities in north-east Scotland. with Eriophorum angustifolium and Erica tetralix This community has been reduced by wide- both constant; the former often extending into spread drainage and cutting of mires, so that often deeper pools and the latter confined to drier areas. just small and modified fragments remain within Drosera rotundifolia is frequent and Narthecium predominantly agriculture landscapes. However ossifragum occasional. Andromeda polifolia, this community readily colonises shallow flooded where present, is distinctive of this vegetation workings and appears to have expanded its cover- type particularly around pool margins, and togeth- age in sites where there has been some agricultural er with Rhynchospora alba it forms a clear sub- enrichment of the water.

M2

Sphagnum recurvum usually Sphagnum recurvum constant absent but Rhynchospora alba and often abundant with no and Andromeda polifolia very Rhynchospora alba and only frequent. occasional Andromeda polifolia.

M2a M2b Rhynchospora alba sub-community Sphagnum recurvum/ cuspidatum sub-community Sphagnum cuspidatum is the typical dominant in the Sphagnum recurvum is Sphagnum carpet. Eriophorum constant with S. cuspidatum angustifolium and Erica tetralix and often the more abundant join Rhynchospora alba and of the two. Eriophorum angusti- Andromeda polifolia as con- folium, Erica tetralix and stants, Drosera rotundifolia is Drosera rotundifolia maintain frequent and D. anglica or their high frequency and D. intermedia occasional. Vaccinium oxycoccos is a good preferential. Polytrichum This sub-community is more commune and Aulacomnium widely distributed on active, palustre can occur sporadically undisturbed raised mires. in slightly drier areas with some Calluna vulgaris and Eriophorum vaginatum. Molinia caerulea may be locally prominent. This sub-community is more restricted to soligenous areas and disturbed basin mires.

20 M3 Eriophorum angustifolium This community is typically found as small stands on barer exposures of acid raw peat soils in bog pool community depressions, erosion channels or shallow peat cuttings on a wide range of mire types. It can be Eriophorum angustifolium is dominant here in found in natural hollows on surfaces of more or swards where other vascular species and less intact mires but is more common among Sphagnum spp. play a relatively minor role. Its erosion features where the peat has been worn shoot density is very variable, as is the sward height down in gullies or redistributed. It is also some- which may be very short or up to half a metre or times associated with abandoned peat workings more. Usually shoots reach approximately 30 cm. on lowland mires. The community is particularly Other vascular plants attain only occasional associated with the eroded blanket mire in the frequency but there can be scattered small tus- north-west of Britain, being a common feature in socks of Eriophorum vaginatum or Molinia tracts of the Calluna vulgaris – Eriophorum vagi- caerulea or sparse individuals of Drosera rotundi- natum and Eriophorum vaginatum mires (M19 folia, Erica tetralix or Empetrum nigrum ssp. and M20), and it is widespread but local in low- nigrum. Bryophyte cover is also very variable and land Erico-Sphagnion mires (M18, M21) and there are no constant species but Drepanocladus Ericion wet heaths (M15, M16). This community fluitans may be frequent, often growing sub- may represent a seral stage in the redevelopment merged. Sparse shoots or small tufts of Sphagnum of active mire vegetation following disruption. spp. may be present, usually S. cuspidatum but sometimes S. recurvum or S. papillosum. No sub-communities.

21 M4 Carex rostrata – abundant as stoloniferous mats), Molinia caerulea, Potentilla erecta, Galium palustre, Rumex ace- Sphagnum recurvum mire tosa, Viola palustris, Succisa pratensis and Stellaria alsine. Usually only one or two of these This mire typically has a cover of sedges over a are present in any one stand. Potentilla palustris, carpet of semi-aquatic Sphagnum spp. Carex ros- Menyanthes trifoliata and Equisetum fluviatile trata is the commonest sedge, usually forming a also may occur occasionally. rather open cover of shoots, but it can be accom- This community is characteristic of pools and panied by C. curta, C. lasiocarpa, C. limosa or seepage areas on raw peat soils of topogenous and C. nigra (the first two especially can be locally soligenous mires where the waters are fairly acid prominent). Carex chordorrhiza is a rare associate. and only slightly enriched. It can occur in bog Occasionally the taller element of the vegetation pools on the surface of basin (and sometimes also has Eriophorum angustifolium, Juncus raised) mires, but is more common in obviously effusus or J. acutiflorus. There is generally an soligenous areas as in mire laggs and the wettest extensive wet carpet of Sphagnum spp. parts of water-tracks. Enrichment is slight and the S. recurvum and S. cuspidatum are usually the pH is typically around 4. The community is of most frequent and abundant species and S. auric- widespread but local occurrence throughout the ulatum is also common. Sphagnum palustre is north-west of Britain and probably remains as occasional, with sparse records for Sphagnum remnants in drained mire systems in the lowlands. subnitens and S. papillosum. S. squarrosum and The place of this community in the terrestrial- S. teres are characteristically rare, which provides ising succession is not clear and the vegetation a good contrast with Carex rostrata – Sphagnum may be very stable provided the high water table squarrosum mire (M5). Other bryophytes are few, and modest irrigation are maintained. Drainage but Polytrichum commune is very frequent form- results in the demise of the more aquatic ing scattered patches. Aulacomnium palustre and Sphagnum spp. and perhaps a transition to Calliergon stramineum are very sparse. the Carex echinata – Sphagnum recurvum/ auric- Scattered through the ground cover are indi- ulatum mire (M6), and with grazing, may result in viduals of an impoverished poor-fen herb flora. a spread of Juncus dominance. The commonest species are Agrostis canina ssp. canina and A. stolonifera (which may be locally No sub-communities.

22 M5 Carex rostrata – Sphagnum latum are occasionally found. Sphagnum contor- tum is rare in contrast with the Carex rostrata – squarrosum mire Calliergon cuspidatum/giganteum mire (M9). Other common bryophytes are Aulacomnium This mire is fairly heterogeneous and is charac- palustre and Calliergon stramineum. terised overall by the dominance of sedges with This mire is typically found as a floating raft or scattered poor-fen herbs over a patchy carpet of on soft, spongy peats in topogenous mires and in moderately base-tolerant Sphagnum spp. The soligenous sites with mildly acid, only moderate- commonest species throughout are Carex rostrata ly calcareous and rather nutrient-poor waters; the and C. nigra, with the former generally more pH range is from about 4 to above 6. It is charac- extensive. Carex lasiocarpa can be locally promi- teristically found in zonations and mosaics, the nent and C. curta is occasionally found. Carex simplest being open water transitions around limosa and C. diandra are typically absent in con- lakes. It can also be found around springs, seepage trast with the Carex rostrata – Calliergon cuspida- lines and streams where it can form part of a mix- tum/giganteum mire (M9). ture of poor- and rich-fen communities. The com- Other vascular plants are often limited to scat- munity has a widespread but fairly local distribu- tered individuals, but the most frequent overall tion in north-western parts of Britain. It was prob- are Potentilla palustris, Eriophorum angustifoli- ably once much more widespread in the lowland um, Menyanthes trifoliata, Galium palustre and south and east where relic stands may still occur. such typical poor-fen herbs as Succisa pratensis, The peat under this community is often very Viola palustris, Ranunculus flammula, Epilobium soft which gives the vegetation a measure of pro- palustre and Lychnis flos-cuculi. Juncus effusus tection against the trampling and grazing effects of can be frequent, as can Molinia caerulea and larger herbivores, although damage may occur Myrica gale. during periodic dry spells. Where the community The bryophyte carpet helps define the Carex – runs onto firmer peats around the margins of Sphagnum squarrosum mire against closely relat- lakes or basins, the vegetation tends to pass to the ed vegetation types. Sphagnum spp. are at least Carex echinata – Sphagnum recurvum/auricula- patchily prominent. Especially distinctive is the tum mire (M6). The effect of grazing on these tran- presence of Sphagnum squarrosum and S. teres. In sitions may favour the spread of Juncus effusus. addition S. recurvum and S. palustre are frequent- ly encountered and S. cuspidatum and S. auricu- No sub-communities.

23 M6 Carex echinata – Sphagnum ossifragum, Drosera rotundifolia and Erica tetralix recurvum/auriculatum mire are found. The rushes Juncus acutiflorus and J. effusus may each be dominant in particular sub- This community has a distinct general character communities. but includes a wide variation in composition, A ground carpet of Sphagnum spp. is promi- expressed here in four sub-communities. Ess- nent and it is most frequently composed of entially it is a poor-fen with small sedges or rush- S. recurvum and S. auriculatum, with occasional es dominating over a carpet of oligotrophic and occurrence of S. subnitens and S. papillosum. base-intolerant Sphagnum spp. The constants are There are only a few other commonly occurring very few. Among vascular plants only Carex echi- bryophyte species. Polytrichum commune is very nata has a uniformly high frequency, but frequent, Rhytidiadelphus squarrosus is occasion- C. nigra and C. panicea are common, and C.demis- al and Calliergon stramineum and Aulacomnium sa occasional. There are two negative characters palustre are patchy throughout. Calliergon cuspi- which aid definition of this community. Firstly, datum and Plagiothecium undulatum are conspic- the general absence of more calcicolous Carex uously rare. species, e.g. C. dioica, C. pulicaris, C. lepidocarpa This mire is the major soligenous community and C. flacca, helps to separate this community of peats and peaty gleys irrigated by rather base- from the Caricion davallianae rich fens (M9 to poor waters in the sub-montane zone of northern M12), and secondly, only local occurrence of and western Britain. The soils and water are quite species like C. rostrata and C. curta marks the veg- acidic with a superficial pH usually between 4.5 etation off from communities like the Carex ros- and 5. It typically occurs as small stands among trata – Sphagnum recurvum mire (M4). other mire communities, grassland and heaths and The most common vascular associates are sometimes with swamp and spring vegetation. It is grasses and poor-fen dicotyledons. Among the commonly found in tracts of unenclosed pasture grasses, Agrostis canina ssp. canina and Molinia on upland fringes, particularly between 200 m and caerulea are the most common but Anthoxanthum 400 m (although it may be found much higher) odoratum is also frequent. Commonly occurring and is ubiquitous in the upland fringes of Britain. poor-fen dicotyledons include Viola palustris and The community is frequently grazed. This, espe- Potentilla erecta, and occasionally one or more of cially where combined with drainage, can convert Galium saxatile, G. palustre, Cirsium palustre, the community to grassland. The exclusion of her- Epilobium palustre, Succisa pratensis, Ranun- bivores would be expected to permit progress to culus flammula or Cardamine pratensis may be wet scrub and woodland, although in many cases present. Sometimes species such as Narthecium this would probably be slow and patchy.

24 Molinia S. capilli- with Sphagnum and carpet. carpet and J. effusus frequent sub-community M6d is dominant over an Molinia S. auriculatum S. papillosum or , common throughout and Juncus acutiflorus usually totally replacing with caerulea and a generally more varied Sphagnum Sphagnum becomes more consistently having dominance in the carpet. wo variants. caerulea herbs frequent. Most of the same poor-fen as listed in M6c are frequent. spp. are generally abundant with S. palustre S. recurvum Juncus acutiflorus Juncus acutiflorus extensive S. subnitens folium This sub-community is found throughout the range of M6. T usually . Juncus effusus Eriophorum J. acutiflorus Sedge cover less varied and extensive and angustifolium sparse; or dominant Molinia , carpet Potentilla are also , is remains frequent carpet canina Sphagnum M6c S. palustre. ssp. sub-community iola palustris . Frequent vascular S. recurvum V is almost always dominant. Juncus effusus the most abundant rush among an extensive Sphagnum usually dominated by with and , and (rather diagnostic here) o variants. caerulea fairly common. The Juncus effusus Sedges are less frequent and abundant and the vegetation is dominated by Juncus effusus associates are few but there is often some Agrostis canina erecta Galium saxatile. Carex echinata is generally extensive and luxuriant S. recurvum Polytrichum commune and sometimes abundant. This sub-community is found throughout the range of M6. Tw M6 , S. and other and J. acutiflorus frequent. Eriophorum and are the spp., with Cirsium palustre. species with poor present among Sphagnum equally , and and M6b is a good preferential, Sphagnum Carex spp. S. subnitens Ranunculus flammula , Nardus stricta S. palustre is very common and Sphagnum is scarce and – Sphagnum being preferential and often Carex nigra C. panicea C. echinata frequent and mixtures of these usually dominate. Nardus stricta Juncus squarrosus very common among a sometimes patchy cover. and Molinia caerulea spp. J. effusus o variants. and ogether with the Carex nigra sub-community T species mentioned above, angustifolium Anthoxanthum odoratum Juncus squarrosus but fen herbs such Epilobium palustre absent. In some stands recurvum commonest In contrast other stands have a greater abundance of S. auriculatum papillosum some the other grasses. This sub-community is found throughout the range of M6. Tw sometimes Juncus Carex usually domi- Eriophorum C. nigra , and , is which C. panicea nate with angustifolium abundant but at most sparse. Mixtures of echinata S. auricula- type of flush. Drosera Carex echina- and canina S. palustre Molinia caerulea exten- occa- and Juncus carpet is typically show some prefer- ssp. Nardus subordi- M6a Eriophorum angusti- and sub-community Sphagnum Juncus bulbosus/kochii S. recurvum Narthecium ossifragum , S. auriculatum , stricta squarrosus sional in an sive carpet. Carex echinata usually the most abundant sedge, C. panicea C. nigra nate and Sphagnum is frequent and may dominate. show a pattern of replacement, the Agrostis canina generally most common; grasses are wo variants. Menyanthes trifoliata ence for the This sub-community is found throughout the range of M6. T Erica tetralix extensive and luxuriant. common but are very common. folium Rushes are typically scarce and of low The cover. tum latter becoming more prominent in the oceanic far west of Britain. rotundifolia Carex echinata The vegetation is generally dominated by mixtures of sedges with ta rather scarce except for and

25 M7 Carex curta – Sphagnum mune, Calliergon stramineum or C. sarmentosum. russowii mire Grasses play a minor role, although Nardus stricta is very common and Agrostis canina ssp. canina This mire community has prominent cyperaceous frequent. Among dicotyledons Viola palustris and and Sphagnum components with a distinct north- Galium saxatile are most common, but are typi- ern and montane character. Eriophorum angusti- cally of low cover. folium and Carex echinata are very frequent and This community is confined to high altitude provide a floristic link with the Carex echinata – sites, usually above 650 m, forming small stands Sphagnum recurvum/auriculatum mire (M6) com- where peaty soils are irrigated by oligotrophic and munity which occurs at lower altitudes, but in base-poor waters. It is characteristic of hollows contrast, C. curta is a constant often with high and drainage channels in blanket mires or flushes cover. It is often accompanied by C. bigelowii or and seepage areas in tracts of montane moss C. aquatilis and C. rariflora. Carex nigra can also heaths. It is an altitudinal replacement for Carex occur, sometimes abundantly. Larger Juncus spp., echinata – Sphagnum recurvum/auriculatum e.g. Juncus effusus and J. acutiflorus,are very mire (M6) with a preponderance of montane scarce, again in contrast to M6. plants. The community is mainly confined to the The Sphagnum carpet is typically extensive. central Highlands of Scotland, but extends south Sphagnum papillosum is common and often into the Pennines and perhaps also into Wales. abundant, and S. subnitens, S. auriculatum, Most of the occurrences of the Carex curta – S. capillifolium or S. recurvum may be frequent. Sphagnum russowii mire are close to or above the The high altitude species S. russowii is constant as potential forest limit in the Scottish Highlands is S. lindbergii in one of the sub-communities. and the community is probably an essentially sta- The rare S. riparium also grows in this community. ble component of the vegetation pattern under Other frequent bryophytes are Polytrichum com- present-day conditions.

M7

Sphagnum lindbergii very Sphagnum lindbergii absent with frequent and usually co-domi- S. recurvum abundant among nant with S. papillosum.Carex frequent S. papillosum and echinata usually co-dominant S. russowii. Carex bigelowii very with C. bigelowii in the vascular scarce and C. echinata usually tier with Nardus stricta dominant. common.

M7a M7b

Carex bigelowii – Sphagnum lindbergii sub-community Carex aquatilis – Sphagnum recurvum sub-community

Carex curta can be common with C. echinata and C. Carex curta is often co-dominant with C. echinata. Some bigelowii but other sedges are scarce. Among the few stands have the rare C. aquatilis and C. rariflora. C. nigra dicotyledons Saxifraga stellaris is preferential. As well as is more common in this sub-community and can be locally the Sphagnum spp. mentioned above, S. subnitens, S. auric- dominant. There is also more diversity among vascular ulatum and S. capillifolium are frequent and S. recurvum associates with Festuca vivipara, Agrostis stolonifera, scarce. Among other bryophytes Polytrichum commune is Deschampsia flexuosa, Luzula multiflora and Galium sax- frequent, but more distinctive are Calliergon sarmentosum, atile all preferential. Nardus stricta is only occasional. Only Drepanocladus exannulatus, Polytrichum alpestre and the Sphagnum spp. mentioned above are frequent. Other P. alpinum. bryophytes are few, but Polytrichum commune is better represented and Calliergon stramineum replaces This sub-community is found throughout the range of M7. C. sarmentosum.

This sub-community is more local being concentrated around the Clova-Caenlochan area of the east Highlands.

26 M8 Carex rostrata – Sphagnum Selaginella selaginoides. Common grasses are warnstorfii mire Festuca ovina (and F. vivipara), Nardus stricta, Anthoxanthum odoratum and Agrostis stolonifera, This community has a dominant cover of sedges all of which are generally present as scattered over an extensive carpet of Sphagnum spp. and a shoots or small tussocks. fairly numerous and diverse assemblage of herbs. This community typically occurs as small Carex rostrata and C. nigra are the commonest stands and is strictly confined to raw peat soils in sedges, the former usually more abundant and of waterlogged hollows in the montane zone of high cover. Other poor-fen sedges, C. panicea, Britain where there is moderate base-enrichment C. echinata and C. demissa occur frequently by drainage from calcareous rocks. These condi- and sometimes abundantly and C. pulicaris is tions are not common. The peat deposits on which occasional. the community is found are typically quite deep, The Sphagnum carpet is typically extensive, usually more than 1 m, with a high and stagnant and the prominence of the base-tolerant water table. The pH of the waters and the peat is Sphagnum teres and S. warnstorfii is quite dis- usually between 5.5 and 6. The small but distinct tinctive. Sphagnum recurvum occurs frequently montane element in the flora of this community and S. subsecundum sensu stricto, although only helps separate it from the Carex rostrata – occurring occasionally, is also very characteristic Sphagnum squarrosum mire (M5) which is found of this community. in analogous situations in the lowlands. The com- Other bryophytes are numerous and in particu- munity is generally confined to altitudes between lar Aulacomnium palustre and Rhizomnium 400 m and 800 m in the central Highlands except pseudopunctatum are frequent. Also distinctive for a few examples in southern Scotland and are Calliergon cuspidatum, C. stramineum and northern England. less frequently C. sarmentosum. Homalothecium The frequent presence of seedlings of Salix nitens is quite common and a good diagnostic aurita in stands of the community may indicate a species. Hylocomium splendens and Rhytidiad- tendency towards the development of montane elphus squarrosus are frequently recorded. willow scrub but such successions have never Herbaceous associates are common but typically been seen to progress further. of low total cover. Constant species are Epilobium palustre, Potentilla erecta, Viola palustris and No sub-communities.

27 M9 Carex rostrata – Calliergon the larger Mniaceae are also common. Campylium stellatum is a distinctive species of this communi- cuspidatum/giganteum mire ty together with Scorpidium scorpioides and Drepanocladus revolvens. This community has a diverse composition and This community is characteristic of soft, physiognomy, even within individual stands, but spongy peats kept permanently moist by at least is generally characterised by a fairly rich moderately base-rich and calcareous waters. assemblage of sedges and vascular plants over a Waters and substrates always have a pH above 5 carpet of bulky mosses and localised patches of and usually above 6. It is commonest in wetter Sphagnum spp. The commonest large sedge is parts of topogenous mires in hollows or old peat- Carex rostrata, which is often abundant and workings, but also around springs, laggs of raised sometimes dominant. Carex diandra is frequent, mires and mowing marshes. The community is and C. lasiocarpa may accompany one or both of widespread but local, ranging from south-east these species. Carex paniculata or C. appropin- England, particularly in Broadland, to Wales and quata is present in some localities. Small sedges northern England and through most of Scotland. which commonly occur in this community The community is limited by the fairly sparse include C. panicea and C. nigra. occurrence of suitable natural situations and in Intermixed with these species, or fringing the lowland south-east by wetland drainage and patches of them, are a variety of associates. the cessation of shallow peat-digging. It is Potentilla palustris and Menyanthes trifoliata are typically too wet to be grazed but in some areas it common and are particularly important when the occurs within mowing marsh that is periodically vegetation forms floating rafts. Also common are cropped. Throughout its range, at least at the Eriophorum angustifolium, Equisetum fluviatile, lower altitudes and in less remote sites, the Carex E. palustre, Succisa pratensis, Pedicularis rostrata – Calliergon cuspidatum/giganteum mire palustris, Cirsium palustre and Ranunculus is probably a successional stage to Salix pentan- flammula often with Galium palustre. Less dra – Carex rostrata woodland (W3) in the north evenly distributed and usually present as and Salix cinerea – Betula pubescens – Phragmites scattered individuals are Mentha aquatica, Caltha australis woodland (W2) in the south-east, palustris, Valeriana dioica, Angelica sylvestris, although development to woodland may be hin- Epilobium palustre and Lychnis flos-cuculi. The dered by a high water table or by the periodic commonest grass to occur in this community is mowing of the vegetation. There is also the possi- Molinia caerulea, particularly in drier stands. bility that under certain conditions this mire type Bryophytes are almost always conspicuous. is seral to the development of poor-fen and Calliergon cuspidatum is constant and C. gigan- ombrogenous mire through the local formation of teum and C. cordifolium frequent. One or more of Sphagnum nuclei.

28 , and , Calliergon Filipendula Mentha aquatica and aleriana dioica sub-community V and , and rare, and Campylium . Angelica sylvestris C. diandra C. lasiocarpa. is locally abundant in eastern M9b Plagiomnium rostratum and common, often , only occasional and ychnis flos-cuculi L Menyanthes trifoliata , , Calliergon giganteum Cardamine pratensis Calliergon cordifolium , – Carex rostrata constant, either or both dominant with or without Herbaceous associates often numerous and lush. stellatum Scorpidium scorpioides Drepanocladus revolvens but C. giganteum with large Mniaceae C. cordifolium , showing their maximum development in this can be prominent with Juncus subnodulosus affine

P. sub-community. This sub-community occurs throughout the range mostly in topogenous mires. Carex diandra Caltha palustris all frequent. Bryophytes are often extensive with The pattern of dominance is more variable here as indicated above. giganteum England. Herbaceous associates are more numerous; Potentilla palustris ulmaria Epilobium palustre M9 . and C. limosa Carex pan- , or spp. are occasion- or and Sphagnum contortum Sphagnum C. lasiocarpa M9a Menyanthes trifoliata usually dominant, C. diandra common but other Campylium stellatum Scorpidium scorpioides species and larger – can be prominent, but most species retain their high frequency and are strongly preferential. Herbaceous associ- Schoenus nigricans. Calliergon cuspidatum Calliergon Mniaceae at most local. Ground carpet usually dominated by mixtures of Scorpidium scorpioides Drepanocladus revolvens. Carex rostrata sometimes with more locally C. nigra and C. echinata Campylium stellatum sub-community Smaller sedges are more numerous than in M9b; icea and ates are variable and not very rich, total cover is low, giving an open community. Potentilla palustris occur as scattered plants. Bryophytes are usually prominent as indicated above. Clumps of al, notably so for the base-tolerant This sub-community is largely north-western in range.

29 M10 Carex dioica – Pinguicula calcicolous species provide a strong definition for vulgaris mire the community against its counterparts in the Caricion nigrae (M5-M7) and in flushed Oxycocco The community includes a range of distinctive – Sphagnetea mires (M14-M21) which occupy calcicolous flush vegetation in which the bulk of similar but more base-poor situations. the sward is composed of small sedges, dicotyle- This community is typically a soligenous mire dons and bryophytes. There are marked variations of mineral soils and shallow peats kept very wet in proportions of frequent species, as indicated in by base-rich, calcareous and oligotrophic waters. the three sub-communities and their variants. The pH of flushing waters is high, usually Essentially this is a small sedge mire with Carex between 5.5 and 7.0 or sometimes higher, and the dioica, C. hostiana, C. lepidocarpa, C. panicea and composition of this community is one of the most C. pulicaris as constants which are also often calcicolous of British mires. It is found in small abundant. Carex nigra is frequent and C. echinata stands, often associated with spring and rill and C. flacca common. Other prominent Cyper- vegetation, within grasslands and more occasion- aceae are Eriophorum angustifolium, a constant, ally in ombrogenous mires and around topoge- and Eleocharis quinqueflora. nous mires. Typically the in situ formation of peat Some rushes and grasses occur frequently. is limited, a feature which helps to distinguish the Juncus articulatus is a constant and J. bulbosus/ habitat of the community from that of base-rich kochii is typical of less base-rich sites. Molinia basins where it is replaced by vegetation like the caerulea is the commonest grass with Festuca Carex rostrata – Calliergon cuspidatum/giganteum ovina more variable in occurrence. Other herbs mire (M9) and the Carex rostrata – Sphagnum generally occur as scattered plants. The frequent warnstorfii mire (M8). It is predominantly a com- occurrences of Pinguicula vulgaris and Selaginella munity of north-west Britain from Wales and the selaginoides are very distinctive of this communi- Pennines northwards, developed in the cool, wet ty. Potentilla erecta and Succisa pratensis are climate. also common species in this community but The community typically occurs in unenclosed Equisetum palustre and Euphrasia officinalis agg. uplands and most of the stands are grazed and are more variable in occurrence. Other species are trampled by large herbivores. It is probably these characteristic of particular sub-communities. factors, combined with nutrient impoverishment Bryophytes are always obvious, often compris- and the often strong and scouring effect of the ing 50% or more of the ground cover. Calcicolous irrigation, which play a major part in maintaining species such as Campylium stellatum, Aneura the community in its generally rich, varied and pinguis, Drepanocladus revolvens, Ctenidium open state. Most stands would probably progress molluscum, Fissidens adianthoides and Craton- to Alno – Ulmion scrub or woodland (W7, W9) if euron commutatum are frequent, together with grazing were withdrawn. However, at higher Bryum pseudotriquetrum. Such assemblages of altitudes the vegetation may be a climatic climax.

30 M10

Carex hostiana, C. pulicaris and Species listed opposite scarce C. nigra all frequent with or absent. Gymnostomum Eriophorum angustifolium and recurvirostrum or less commonly Molinia caerulea. Potentilla Catascopium nigritum forming erecta and Succisa pratensis hummocks with Drepanocladus common with Ctenidium revolvens and Cratoneuron molluscum and Fissidens commutatum often abundant. adianthoides frequent.

Carex demissa and Carex demissa and M10c C. echinata occasional C. echinata scarce, to frequent; C. lepido- but C. lepidocarpa, Gymnostomum recurvirostrum carpa and C. flacca C. hostiana, C. pulicaris sub-community scarce and C. pulicaris and C. flacca frequent. patchy. Juncus bulbo- Juncus bulbosus and Vascular plants have low sus and Erica tetralix Erica tetralix only of individual and total cover; quite common. local significance. much more prominent are the conspicuous moss hummocks, particularly of Gymnostomum recurvirostrum which are up to M10a M10b 30 cm high and 60 cm across. There is much bare ground with Carex demissa – Juncus Briza media – Primula a fragmentary cover of vascular bulbosus/kochii sub-community farinosa sub-community plants; good preferentials are Plantago maritima, Sagina This comprises the less Vascular plants are also nodosa and Minuartia verna. calcicolous types of M10 with prominent but many swards M. stricta is restricted to this vascular plants predominant. are open with extensive bare sub-community in its only Carex panicea, C. dioica, ground. Calcicoles and more British locus. C. hostiana and C. nigra remain mesophytic herbs well very frequent with the species represented. Carex lepidocarpa, This striking vegetation is only listed above. More calcicolous C. hostiana and C. pulicaris are recorded from Upper Teesdale. herbs such as Briza media, consistently frequent and com- Primula farinosa, Linum monly accompanied by C. flac- catharticum and Sesleria ca. Among the preferentials albicans are usually poorly Briza media, Primula farinosa, represented. Bryophytes are Linum catharticum, Sesleria generally less prominent in the albicans and Equisetum turf; Bryum pseudotriquetrum, variegatumare frequent. Juncus Fissidens adianthoides and bulbosus/ kochii, Erica tetralix, Ctenidium molluscum are Narthecium ossifragum and rather uncommon and Drosera rotundifolia are Campylium stellatum and reduced in their occurrence. Scorpidium scorpioides Among the bryophytes Aneura rather more prominent. pinguis, Ctenidium molluscum and Fissidens adianthoides are This sub-community is largely consistently frequent. restricted to Scotland and the Lake District with outlying This sub-community is occurrences in north-west predominantly found in Wales and Upper Teesdale. northern England.

Three variants. Three variants.

31 M11 Carex demissa – Saxifraga very common at higher altitudes, and occasionally Saxifraga stellaris, S. oppositifolia and Alchemilla aizoides mire filicaulis ssp. filicaulis. Typically all these species occur in an uneven and broken sward. This vegetation is typically open with rich mix- Bryophytes are frequent and varied. Aneura tures of small sedges, other herbs and bryophytes pinguis, Campylium stellatum, Drepanocladus among water-scoured runnels and with much revolvens, Bryum pseudotriquetrum, and at lower exposed silt and rock debris. There is a strong altitudes, Cratoneuron commutatum, Fissidens floristic link with Carex dioica – Pinguicula vul- adianthoides, Ctenidium molluscum and Scor- garis mire (M10) but the Arctic-Alpine element of pidium scorpioides are all common. The montane the vegetation is much more pronounced in this moss Blindia acuta can be prominent at higher community than it is in M10. Typically there is no altitudes and is a good preferential for this com- single dominant. Carex demissa, C. panicea and munity. C. pulicaris are very frequent throughout and This community is characteristic of open, C. flacca and C. dioica are common in some vari- stony flushes, strongly irrigated with moderately ants. Juncus articulatus is a constant, Eriophorum base-rich waters, on generally steep slopes in sub- angustifolium is frequent as is Eleocharis quin- montane and montane parts of Britain. Although queflora at lower altitudes. At higher altitudes the community can occur almost at sea level in the Juncus triglumis is constant and Tofieldia pusilla far north-west of Scotland, it is generally confined becomes frequent. By comparison with M10, to high altitudes. It is always associated with cal- C. lepidocarpa and C. hostiana are much less com- careous bedrocks having a soil pH range of 5.5 to mon and C. nigra and C. echinata also rather 7.0. Flushing is vigorous and erosion of the sur- scarce. At higher altitudes there is an Arctic- face is therefore often pronounced and the soil Alpine element with Juncus triglumis being con- cover little more than scoured accumulations of stant and Tofieldia pusilla becoming more fre- silt and organic matter with exposed rock debris. quent. Grasses are typically low in cover. Festuca It is largely confined to Scotland, but also present ovina/vivipara is common and Agrostis stolonifera in the Lake District, and more locally in the occasional. At higher altitudes Deschampsia Southern Uplands, the northern Pennines and cespitosa (including D. alpina), Nardus stricta, north Wales. Anthoxanthum odoratum, Agrostis canina ssp. The community is normally grazed and this canina and Festuca rubra may be present. grazing may help maintain the open structure and Other herbs found in this community include help prevent the development of a woody cover. Pinguicula vulgaris and Saxifraga aizoides which However, colonisation of trees and scrubs would are both constant and Selaginella selaginoides be slow due to the climatic conditions in which which is very frequent. The montane element of this the community occurs and at higher altitudes the community includes Thalictrum alpinum, which is mire is probably a climatic climax.

M11

Juncus triglumis and Thalictrum alpinum constant, Eleocharis quinqueflora constant with Juncus triglumis but Eleocharis quinqueflora uncommon. Deschampsia and Thalictrum alpinum becoming more frequent at higher cespitosa, Nardus stricta and Anthoxanthum odoratum altitudes. The grasses found in M11a at most occasional. frequent and Alchemilla alpina occasional. Cratoneuron Cratoneuron commutatum and Scorpidium scorpioides very commutatum, Scorpidium scorpioides and Fissidens common and abundant, often with Fissidens adianthoides. adianthoides all scarce. M11b Cratoneuron commutatum – Eleocharis quinqueflora sub-community M11a Thalictrum alpinum – Juncus triglumis sub-community In this sub-community M11 grades into M10 with more extreme montane plants, except Saxifraga aizoides and There is an obvious montane element in the vegetation as Blindia acuta, much more poorly represented; and in more indicated in the species above. Saxifraga aizoides, Carex southerly stands even these become rare. Eleocharis quin- demissa and C. panicea are usually the most abundant queflora is constant and sometimes abundant, rivalling the vascular plants with Blindia acuta, Campylium stellatum or sedges, among which Carex hostiana and, in wetter stands, Drepanocladus revolvens predominating among the mosses. C. rostrata are sometimes found. Vascular plant cover typically more extensive than in M11a. This is the typical form of M11 at higher altitudes and is virtually confined to Scotland. This sub-community is also frequent in Scotland at lower altitudes and in most of the English and Welsh stands. Two variants.

32 sional. Hylocomium splendens is also a constant M12 Carex saxatilis mire as is Scapania undulata. There can also be some small patches of Sphagnum spp. Carex saxatilis is typically dominant in this This mire type is strictly confined to margins of montane mire with a distinctive assemblage of high-montane flushes irrigated with base-rich and associates. The sward is generally less than 20 cm calcareous waters perhaps influenced by long high and rather open with patches of soil. Carex snow-lie. It typically occurs as small stands bor- demissa, C. echinata and C. nigra are very fre- dering rills or more strongly irrigated soligenous quent and can be abundant. Carex bigelowii is fair- mires. The soils that this community is found on, ly consistent, especially in grassy transitions to though continuously irrigated, are not of especial- surrounding swards. ly high pH, ranging from 4.6 to 6.3. The commu- Eriophorum angustifolium is also frequent nity is fairly widespread but local on peaks above attaining a cover of more than 10%. Almost all 750 m through the southern and central Scottish other herbs occur as scattered individuals. Highlands with scattered localities in north-west Selaginella selaginoides and Pinguicula vulgaris Scotland. are both very common as in other calcicolous The physical effects of flushing, snow-melt, flushes, but more distinctive are Thalictrum cryoturbation, and solifluctional flow result in the alpinum, Polygonum viviparum, and Juncus trig- continual instability of the substrate on which this lumis. Saxifraga aizoides is infrequent, in contrast community is found and this is important in to Carex demissa – Saxifraga aizoides mire (M11). maintaining open stony areas where rare Also common are the poor-fen herbs Viola palus- Arctic-Alpine sedges and rushes find a niche. It is tris, Caltha palustris and Agrostis canina ssp. canina. possible that grazing prevents colonisation by Bryophytes are an important element of the Arctic-Alpine willows; however, in the extreme vegetation although apart from the constant environment in which it occurs the community is Drepanocladus revolvens, cover of individual probably a climatic climax. species is low. Aneura pinguis is frequent and Bryum pseudotriquetrum, Blindia acuta, Campy- No sub-communities. lium stellatum and Calliergon trifarium are occa-

33 M13 Schoenus nigricans – Juncus frequently the constant Potentilla erecta and Erica subnodulosus mire tetralix. Bryophytes vary in cover and species but can In this community Schoenus nigricans is typically be very extensive. The commonest throughout are very frequent and consistently associated with Campylium stellatum and Calliergon cuspidatum. other distinctive floristic features. It is generally Other frequent species include Drepanocladus dominant (although it may be absent from frag- revolvens, Aneura pinguis, Cratoneuron commu- mentary stands) giving a grey-green appearance to tatum and C. filicinum. the vegetation. Commonly it is intermixed with This community is confined to peat or mineral Juncus subnodulosus, and where this predomi- soils, in and around lowland mires irrigated by nates the vegetation is olive-green in spring and base-rich, highly calcareous, and oligotrophic reddish brown in winter. Molinia caerulea is also waters. It is often found below springs and seep- constant. These species form a rough sward about age lines and on flushed margins of valley mires, 50 cm in height with smaller herbs growing in- but also extends into topogenous basins provided between. Sedges are often important, particularly there is close contact with waters draining from Carex panicea, C. lepidocarpa and C. flacca. lime-rich substrates. The flushing waters typically Where the summer water table is close to the have pH between 6.5 and 8. It is widespread but surface, species such as Equisetum palustre, local throughout lowland England and Wales, but Pedicularis palustris, Mentha aquatica, Valeriana is restricted by natural scarcity of suitable habitat dioica and Cardamine pratensis occur, sometimes and its extensive destruction. with Parnassia palustris, Pinguicula vulgaris and The structure and floristics of this community Eriophorum latifolium. A variety of orchids are are often influenced by grazing and some stands found, particularly Epipactis palustris. Taller have been affected by mowing and burning. herbs can be locally abundant with Succisa Shallow peat-digging has been locally important pratensis being most common. Phragmites australis in providing a suitable habitat for the community is also frequent, particularly in ungrazed stands. but more drastic treatment of mires, particularly On drier areas and particularly tops of Schoenus draining and eutrophication, have reduced its tussocks less calcicolous plants are found, most extent and eliminated it from some areas.

34 M13

Juncus subnodulosus and Molinia General floristic and structural features well preserved, with at least caerulea often very abundant with some of Anagallis tenella, Pedicularis palustris, Angelica sylvestris, Schoenus nigricans markedly Cirsium palustre, Mentha aquatica, Equisetum palustre and Phragmites reduced in vigour. Festuca rubra, australis frequent. Holcus lanatus, Agrostis canina and A. stolonifera frequent and tall herbs, orchids and bryophytes Carex hostiana and C. pulicaris very Many smaller runnel herbs sporadic, but patchy. frequent among an abundant and diverse Caltha palustris and Valeriana dioica small herb flora in runnels with Briza become common and taller dicotyledons media, Pinguicula vulgaris, Linum are often prominent with Filipendula catharticum, and Juncus articulatus com- ulmaria, Eupatorium cannabinum and mon. Lychnis flos-cuculi frequent.

M13a M13b M13c Festuca rubra – Juncus acutiflorus Briza media – Pinguicula vulgaris sub- Caltha palustris – Galium uliginosum sub-community community sub-community This comprises the more impover- This kind of Schoenetum is strikingly Schoenus nigricans, Juncus subnodulo- ished stands of M13. Apart from rich. Mixtures of Schoenus nigricans, sus and Molinia caerulea remain of the reduction or even absence of Juncus subnodulosus and Molinia structural importance but are variously Schoenus nigricans and presence caerulea usually share dominance but augmented by Carex rostrata, C. diandra, of the species mentioned above, the small herbs of runnels are especially C. elata, Cladium mariscus and some- Carex panicea, C. lepidocarpa, and distinctive. Apart from the species men- times Phragmites australis. Runnels are C. flacca are also important in run- tioned above, Parnassia palustris is fre- well developed but smaller preferentials nels. Anagallis tenella is totally quent often with mixtures of orchids of M13b are only occasional. The com- absent and Pedicularis palustris, including Gymnadenia conopsea var. monest species are Carex panicea, C. lep- Epipactis palustris and other densiflora, Dactylorhiza fuchsii, idocarpa, Mentha aquatica, Hydrocotyle orchids are very scarce. The com- D. majalis ssp. purpurella and Epipactis vulgaris together with the preferentials monest herbs are Succisa pratensis palustris. Along with Succisa pratensis Caltha palustris and Valeriana dioica. In and Hydrocotyle vulgaris. and Serratula tinctoria, taller herbs are addition to Epipactis palustris there is Bryophytes are generally sparse represented by frequent Angelica often Dactylorhiza incarnata, D. majalis and low in number with Calliergon sylvestris, Cirsium palustre, Eupatorium ssp. praetermissa and sometimes cuspidatum the commonest cannabinum and Oenanthe lachenalii. D. traunsteineri. Taller herbs are species. Bryophytes are quite numerous and common, as listed above, with sprawling sometimes of high cover. Galium uliginosum and less commonly This sub-community occurs G. palustre. A pool element is sometimes through the range of M13. This sub-community occurs in Anglesey present, with Carex rostrata and C. dian- and East Anglia. dra together with Menyanthes trifoliata, Equisetum fluviatile and Utricularia species. This sub-community is concentrated in East Anglia.

35 M14 Schoenus nigricans – M15 Scirpus cespitosus – Narthecium ossifragum mire Erica tetralix wet heath

This is a vegetation type with few constants and a This mire type includes mildly calcicolous wide variation in the pattern of dominance and Schoenus vegetation of south-west England that is in associated flora. Molinia caerulea, Scirpus not readily integrated into Schoenus nigricans – cespitosus, Erica tetralix and Calluna vulgaris are Juncus subnodulosus mire (M13) and with a less all of high frequency and it is mixtures of these varied flora. Schoenus nigricans is usually domi- species that give the vegetation its general nant and Molinia caerulea is generally abundant. character. However, sometimes one or two of them A mixture of these two species usually cover the may be missing and their relative proportions are ground. Juncus subnodulosus is absent in contrast very diverse. Molinia is the most consistent over- to M13. Small calcicolous herbs are generally all and often abundant; in other stands Scirpus is absent. Narthecium ossifragum and Anagallis very prominent and both may share dominance tenella are constants while Drosera rotundifolia, with Calluna. Molinia may also dominate with growing on cushions of Sphagnum, is less com- Scirpus or with Erica tetralix. The shrubby species mon. Erica tetralix, or occasionally Calluna vul- Erica cinerea, Vaccinium myrtillus and Myrica garis,grows on Schoenus or Molinia tussocks. gale are important in particular sub-communities. Some stands have a local abundance of Myrica Other common species are Potentilla erecta, gale. and in moister stands, Polygala serpyllifolia, Bryophytes are variable and also less calcicolous Narthecium ossifragum and Eriophorum angusti- in character than in M13. Campylium stellatum and folium. By contrast E. vaginatum is notably scarce. Aneura pinguis are frequent and together with There are few bryophytes common throughout. Scorpidium scorpioides and, less commonly, There are usually some Sphagnum spp. but they Drepanocladus revolvens, can form extensive mats do not form the luxuriant carpets of the in runnels. Sphagnum spp. are a consistent feature, Sphagnetalia mires (M17-M21). The most frequent particularly on tussocks. Sphagnum subnitens is species overall are Sphagnum capillifolium and most common and S. auriculatum is frequent. S. subnitens. Sphagnum palustre, S. recurvum Hypnum jutlandicum is preferential and there may and S. auriculatum can become common in wetter be patches of hepatics including Kurzia pauciflora stands. Lichens do not appear consistently but and Calypogeia species. Cladonia spp. can be locally prominent. This community is characteristic of peats and This wet heath community is characteristic of mineral soils irrigated by moderately base-rich moist and generally acid and oligotrophic peats and calcareous ground waters of a pH range and peaty mineral soils in the wetter western and between 5 and 7. It characteristically occurs as iso- northern parts of Britain. It is associated with thin- lated flushes among wet heath and moorland veg- ner or better drained areas of ombrogenous peat etation, but it is also associated with soligenous with a surface pH typically between 4 and 5. The zones within valley mires. The community occurs community is particularly well represented in the very locally in Cornwall, east Devon, south-east west and south-west of Scotland, through Wales Dorset and the New Forest. It may also be found in and less extensively in the Lake District, Dartmoor Wales but it is replaced in comparable situations and Exmoor. on north-western blanket bogs by Schoenus-domi- Grazing and burning have important effects on nated stands of Scirpus cespitosus – Erica tetralix the floristics and structure of this community, and wet heath (M15). draining and peat-cutting have extended its The community only occurs very locally. This coverage to formerly deeper and wetter peats. is partly because of the natural scarcity of suitable Without burning or grazing, less damaged stands habitats, but also because of the reduction in its may be able to revert to blanket mire. However, extent by human activities such as drainage and cessation of burning, especially on peat that is agricultural improvement. Occasional burning well aerated or where there has been drainage, and light grazing are also of common occurrence may precipitate a vigorous expansion of Molinia. over the tracts of heath in which this kind of mire Although progression to woodland is theoretically usually occurs, although these activities are possible over most, if not all, of its altitudinal probably not very damaging. In the absence of range, widespread deforestation has often re- grazing or burning it is expected that some stands moved potential seed-parents, and continued of this community would progress towards grazing by livestock and deer and sporadic burn- wet woodland. ing may be enough to set back succession contin- No sub-communities. ually. However, extensive tracts of this kind of vegetation have been replaced by coniferous forest after the ground has been drained.

36 , , , , and Erica spp. are spp. and fre- and and and more Pleurozium sub-community , Deschampsia Juncus , Anthoxanthum rare but and Cladonia Juncus squarrosus M15d generally dominate , and spp. scarce. Racomitrium and . accinium myrtillus. Molinia caerulea V Festuca ovina/vivipara Plagiothecium undulatum , , Luzula multiflora fairly both rather uneven, often , accinium myrtillus Scirpus cespitosus Erica cinerea V quent, commonly with Nardus stricta squarrosus flexuosa lanuginosum Cladonia Nardus stricta rubra

accinium myrtillus V Mixtures of Calluna vulgaris with tetralix with some Polytrichum commune Rhytidiadelphus loreus. Racomitrium lanuginosum are scarce. This sub-community is especially common in the drier regions of distribution of M15. Commonly there are small tussocks of Carex pilulifera. Sphagnum infrequent, their place being taken by Hypnum cupressiforme/jutlandicum Dicranum scoparium schreberi Deschampsia flexuosa occasionally some odoratum F. . , and and com- remains become usually s and C. gracilis spp. les Narthecium ossifragum common, but other species listed opposite all scarce. e rare. C. arbuscula and Sphagnum ar spp. are abundant, frequent, Cladonia M15c Potentilla erecta Calluna vulgaris Polygala serpyllifolia C. coccifera Cladonia impexa very scarce. , together with spp. sub-community Cladonia Eriophorum angustifolium accinium myrtillus Erica cinerea sometimes abundant, but V Racomitrium lanuginosum common and often abundant. Racomitrium lanuginosum This sub-community is especially common in the drier regions of distribution of M15. C. pyxidata spp. are only poorly represented and Hypnum cupressiforme/jutlandicum and frequent. C. uncialis particularly mon and constant, but Narthecium ossifragum Myrica gale Cladonia All four possible dominants have high frequency but predominates. M15 and and Juncus is a C. echina- often Molinia y sparse, sub- Eriophorum and or Calluna and and Myrica gale provide most Sphagnum and carpet Calluna vulgaris Sphagnum papil- generall and may predominate, M15b S. papillosum are frequent as in M15a, Carex panicea Erica tetralix Nardus stricta Sphagnum Hypnum cupressiforme may show local promi- , Carex panicea and and Eriophorum vaginatum is frequent and locally abundant Drosera rotundifolia small sedges at most occa- sional. but patchy, quite frequent. Odontoschisma sphagni occasional and fen associates very Myrica ypical sub-community alone may be dominant. is quite common but not abundant. Narthecium ossifragum angustifolium but small sedges are with only ta uncommon. squarrosus nence. low-cover occasional. losum and present. In some stands spp. are sparse and mosses such as Racomitrium lanuginosum, Dicranum scoparium Campylopus paradoxus of the cover. This and the community are particularly common in the west of Scotland. Molinia caerulea Molinia T The dominants here are very variable. Scirpus cespitosus may share dominance, or Sphagnum , common. is , , Erica , often found. and and Polygala ssp. gale Narthecium ossifragum palustre Eriophorum angustifolium frequent with retain high carpet is and also often Molinia and C. panicea C. echinata , , C. demissa almost totally , Succisa pratensis S. capillifolium , Sphagnum common and M15a are more sparse. E. cinerea sub-community Juncus bulbosus Sphagnum , Erica tetralix are very commonly found sometimes has local Sphagnum recurvum Scirpus cespitosus The Selaginella selaginoides C. nigra. S. subnitens. Drosera and C. pulicaris , Carex panicea , Potentilla erecta Carex echinata Sphagnum palustre Narthecium ossifragum and Usually small stands, often in soakways. carpet extensive with fre- quent and rotundifolia scattered small sedges such as Dactylorhiza maculata iola palustris accinium myrtillus and maculata. caerulea This is the richest and most floristically distinct sub-community. frequency; Calluna vulgaris V Carex panicea Myrica gale abundance, but V also distinctive, as indicated above, with angustifolium. Drosera rotundifolia preferential with a variety of species such as serpyllifolia with absent. Pinguicula vulgaris abundant and with patchy. sub-community This and the Typical are particularly common in the west of Scotland. C. nigra C. dioica

37 M16 Erica tetralix – Sphagnum Sphagnum spp. as well as a number of other bryophytes, between the dominants. Lichens may compactum wet heath also be present, especially larger Cladonia species such as C. impexa and C. uncialis. This community is characteristically dominated This wet heath community is found on acid by mixtures of Erica tetralix, Calluna vulgaris and and oligotrophic mineral soils or shallow peats Molinia caerulea, but their proportions are very that generally have a surface pH of between 3.5 variable, being influenced by differences in the and 4.5 and that are at least seasonally water- water regime and trophic state of the soils, and logged. It is characteristic of the south of lowland also by grazing and burning. Erica tetralix is often England, being particularly associated with the vigorous, particularly on wetter soils, while surrounds of valley mires maintained by a locally Calluna is often subordinate and weak (although it high water table. It is also found through Wales, may be abundant in drier stands or where and in northern England and Scotland, where it controlled burning is carried out). No other sub- extends on to thin ombrogenous peats at higher shrubs attain a high frequency, although Erica altitudes. cinerea and Ulex gallii may be abundant in Grazing and burning are important in main- transitions to drier heaths in south-west England taining the vegetation, and burning is able to and E. cinerea and U. minor can occur in similar transform the appearance of particular stands over situations further east. In some situations Molinia short periods of time, producing considerable may be dominant. structural diversity within a small area. Without This community may have no other, or only any grazing or burning most stands would proba- sporadic, vascular associates. The commonest vas- bly progress to woodland, and this has happened cular associate, where present, is Scirpus cespito- to some stands lying within tracts of heath on sus. Eriophorum angustifolium and Narthecium commons in south-east England where traditional ossifragum are quite frequent, as is Drosera rotun- management has fallen into disuse. The combina- difolia in wetter hollows. Myrica gale occurs occa- tion of frequent burning, draining, and damage sionally, sometimes with local abundance. due to other operations such as military manoeu- Most characteristic of the bryophyte layer in vres and mineral extraction, have led to an irre- drier situations is Sphagnum compactum, a con- trievable loss of this community in many areas stant and strong preferential for the community. In and its distribution has been considerably frag- wetter places S. tenellum may be present. These mented with remaining stands closely hemmed in species may occur as scattered cushions or form a by coniferous plantations or intensive agricultural continuous carpet, sometimes with several other land.

38 are and Hypnum , can S. tenellum . Erica , and is very Erica tetralix Molinia caerulea Kurzia pauciflora M16a can be found in this carpet often very , Scirpus cespitosus and and Cladonia impexa Juncus squarrosus Calluna vulgaris ry variable mixtures and Sphagnum patchy and sometimes absent and M16c associates hardly ever found. tetralix generally dominate with occasional and Other associates listed for M16d rare. Ve of ypical sub-community can be very frequent and often abun- dant. Among other bryophytes jutlandicum the commonest species, while Campylopus brevipilus consistent in some areas. Lichens, particularly also be frequent. This sub-community is found throughout the south of Britain and as more impoverished stands further north. T All variations in the proportions of Molinia caerulea Calluna vulgaris sub-community so the appearance is very diverse. Where their cover is open, Sphagnum compactum Scirpus cespitosus Narthecium ossifragum generally frequent but listed associates of M16b usually uncommon. . often S. subnitens Scirpus S. tenellum reduced in Cladonia impexa and Dicranum Juncus Dicranum , – and is more frequent Cladonia Hypnum rarely has high cover Racomitrium M16d is usually dominant. and . Erica tetralix , especially common. Sphagnum compactum retains constancy, retains constancy, sub-community Calluna vulgaris S. capillifolium cupressiforme scoparium lanuginosum Diplophyllum albicans all common. species often present. squarrosus Frequent tussocks of cespitosus frequency and abundance and Molinia caerulea exceeding C. uncialis Juncus squarrosus scoparium Molinia caerulea and may be absent although Erica tetralix Calluna vulgaris Scirpus cespitosus and has higher cover than in other sub- communities. is often abundant and has a high frequency together with while and are relatively scarce. Together with are relatively scarce. Together the bryophytes listed above lichens are often prominent, with This is the usual sub-community in north and east of Britain. M16 . and and , S. tenellum More . Calluna vul- and and Drosera Erica tetralix as sub- – and M16c Sphagnum D. intermedia species, particularly Kurzia pauciflora R. fusca sub-community Scirpus cespitosus Drosera rotundifolia . There are scattered small tter hollows and runnels Narthecium ossifragum is less common and the cover of Sub-shrub cover generally but patchy, carpet quite extensive with frequent We have and often Rhynchospora alba locally community preferentials. Cladonia Rhynchospora alba intermedia Molinia caerulea remain very frequent but Eriophorum angustifolium distinctive are the preferentials listed above. This sub-community is concentrated in the New Forest and Poole Harbour. garis all three is reduced. In the intervening open areas is an extensive cover of Sphagnum compactum C. impexa tussocks of often with leafy hepatics and locally promi- nent , and having and Carex frequent, Myrica usually – Erica tetralix being con- Polygala tends to Scirpus Narthecium Serratula Cirsium Carex panicea Sphagnum , M16b , less common can be frequent and and Bryophytes sub-community Potentilla erecta sometimes shows local Calluna vulgaris Potentilla erecta dissectum tinctoria. usually sparse. Salix repens serpyllifolia Succisa pratensis with occasional cespitosus ossifragum than usual, scattered plants of Molinia caerulea dominant with high frequencies. The vascular flora is richer than in M16a with Succisa pratensis stant and the species listed above preferential. Succisa pratensis Molinia caerulea and gale abundance. Bryophytes and lichens tend to be less common in this sub-community, but unusually auriculatum and locally abundant. This sub-community occurs throughout south-west England and perhaps elsewhere. panicea predominate with

39 M17 Scirpus cespitosus – nied by S. tenellum, S. subnitens and other Eriophorum vaginatum blanket mire species, forming luxuriant carpets. Such carpets typically have a variety of leafy hepatics including This community is dominated by mixtures of Odontoschisma sphagni, Mylia anomala, M. tay- monocotyledons, ericoid sub-shrubs and Sphagnum lori and Pleurozia purpurea. Racomitrium lanugi- spp. It can occur as extensive, relatively uniform nosum is a common moss throughout, but becomes tracts, or as hummock and hollow complexes, abundant on hummock tops and in degraded with this community giving way to bog pool vege- mires. Lichens, particularly larger Cladonia tation in the hollows. Among the bulkier vascular species, can be prominent and tend to be associat- species, the most common are Scirpus cespitosus, ed with R. lanuginosum. Eriophorum vaginatum, Molinia caerulea, Calluna This community is the characteristic blanket vulgaris and Erica tetralix; mixtures of which form bog vegetation of the more oceanic parts of Britain, a rather open uneven-topped tier which is 20- occurring extensively on waterlogged ombroge- 30 cm tall. Myrica gale also has occasional local nous peat. The peats show varying humification abundance in this stratum. but are typically highly acidic, with a surface pH Eriophorum angustifolium and Narthecium usually not above 4 and often less. It is a commu- ossifragum are both very frequent and Drosera nity of lower altitudes where extreme humidity is rotundifolia is very common in wetter areas. combined with a relatively mild winter climate. It Potentilla erecta is a constant which helps to dis- is largely confined to western Britain from the tinguish this community from other Sphagnetalia western Highlands of Scotland and the Western mires (M18-M21). Other species found at low fre- Isles, to south-west Scotland, the Lake District, quencies throughout are Pedicularis sylvatica, Wales and south-west England. Huperzia selago, Juncus acutiflorus, Festuca ovina Burning, marginal peat-cutting, and drainage and Carex echinata. Vaccinium myrtillus, Empetrum have often resulted in surface drying of the peat nigrum ssp. nigrum and Rubus chamaemorus and hence a modification of the vegetation. It is are all scarce, in contrast to Calluna vulgaris- also possible that natural climatic change too has Eriophorum vaginatum blanket mire (M19). played a part in the degeneration of the blanket Sphagnum spp. are an important component of bogs occupied by this type of community. the ground layer. Sphagnum capillifolium and However, this community still remains as climax S. papillosum are constants and may be accompa- vegetation in the more oceanic parts of Britain.

40 , is cani- can be rare. , , are all ssp. alpestre

sub- is absent and P. , Cladonia are the main and especially Erica cinerea Deschampsia flexu- accinium myrtillus Campylopus Cladonia V Deschampsia flexuosa Luzula multiflora and , , but Myrica gale Agrostis canina and Sphagnum papillosum and Dicranum scoparium Aulacomnium palustre occasional and M17c , spp., Erica tetralix and Scirpus cespitosus Rhytidiadelphus loreus Polytrichum commune Nardus stricta – Nardus stricta , , being reduced. Pohlia nutans and , , and with them Hypnum cupressiforme/jutlandicum Empetrum nigrum Sphagnum very scarce. There is a marked increase in are more occasional but preferential. Carex nigra Anthoxanthum odoratum frequent with small amounts of , paradoxus This sub-community along with the community occurs in the west but they extend range of the community on to drier peats, most notably in south-west and eastern Scotland. Juncus squarrosus sub-community Calluna vulgaris Molinia caerulea Erica cinerea Juncus squarrosus and na vascular dominants with Plagiothecium undulatum Ptilidium ciliare found. Of the usually the most abundant. There is a distinctive contin- gent of mosses: Rhytidiadelphus loreus very frequent, while species uncommon. and occasional osa Racomitrium lanuginosum Juncus squarrosus Drosera Erica Calluna Scirpus at most Sphagnum rare. Molinia caerulea , with and and rotundifolia occasional. cover rather impoverished and leafy hepatics infrequent. The usual vascular dominants are vulgaris cespitosus tetralix of reduced importance and Myrica gale and and Sphagnum Eriophorum spp. are is scarce and are fairly Mylia taylori Empetrum nigrum Juncus – C. arbuscula. occasional and locally and Cladonia Juncus squarrosus Molinia caerulea and Myrica gale and very common with several and M17b preferential at low frequencies. Scirpus cespitosus M17 Erica cinerea C. uncialis sub-community occurs in the west but , and albicans quite frequent and locally prominent. The playing a subordinate role and as the main species, often rather patchy, as the main species, often rather patchy, accinium myrtillus Nardus stricta M17a are uncommon, with carpet is much impoverished with distinctly patchy. distinctly patchy. V spp. sub-community species. and all other species reduced in frequency. The leafy and all other species reduced in frequency. hepatics of capillifolium Diplophyllum Racomitrium lanuginosum increased in frequency and abundance, particularly Cladonia impexa This sub-community along with the they extend the range of community on to drier peats, most notably in south-west and eastern Scotland. Rhytidiadelphus Calluna vulgaris Cladonia consistent co-dominants with Erica tetralix vaginatum Erica cinerea Sphagnum occasional. Racomitrium lanuginosum Cladonia abundant. very scarce. and are and Molinia Sphagnum Sphagnum carpet Molinia Drosera – locally Scirpus cespitosus S. compactum Erica tetralix and Sphagnum and S. papillosum very frequent M17a and Drosera rotundifolia Eriophorum vaginatum S. tenellum usually well is also frequent but only and frequent. Common leafy Pleurozia purpurea Sphagnum Myrica gale usually make up the bulk of and plentiful. Extensive and varied rotundifolia Erica tetralix represented with caerulea with leafy hepatics often prominent. Calluna vulgaris in wetter parts. caerulea with the cover, sometimes showing local abundance in higher areas and is strongly preferential. spp. are extensive; capillifolium most abundant with Drosera rotundifolia occasional and or spp. sub-community This has a consistent representation of all the community constants. Among vascular dominants mixtures of Calluna vulgaris S. subnitens hepatics are Odontoschisma sphagni. Racomitrium lanuginosum as scattered shoots. This sub-community occurs throughout the range of M17, but it is particularly extensive in north-west Scotland.

41 M18 Erica tetralix – Sphagnum S. magellanicum, and a little S. tenellum predom- papillosum raised and blanket mire inate on the surrounds to wetter depressions. Other bryophytes are generally subordinate but This community is generally dominated by can be frequent and locally abundant. The leafy Sphagnum spp. Ericoid sub-shrubs and mono- hepatics Odontoschisma sphagni and Mylia cotyledons are often subordinate. It can be found anomala are both common, but Pleurozia pur- as undulating carpets or can comprise lawn and purea is generally absent. Aulacomnium palustre hummock components. The bulkier vascular plants and Hypnum cupressiforme/jutlandicum are fre- typically form a low, patchy canopy with Calluna quent mosses. vulgaris, Erica tetralix and Eriophorum vaginatum This vegetation is characteristic of waterlogged being the commonest species and Scirpus cespito- ombrogenous peats, typically at low altitudes in sus slightly less frequent. Erica tetralix tends to moderately oceanic parts of Britain. It is charac- predominate on wetter ground where shoots of teristic of raised bogs where it is the main com- Eriophorum angustifolium can also be abundant. munity of the active plane, but is also found with- Calluna, Scirpus and E. vaginatum are found more in blanket mires and in some basin mires on acid typically on the drier areas. peat. The peats it covers are usually deep with a Sphagnum spp. make up the most important uniformly acid surface with a pH of about 4, and component of the vegetation. Both Sphagnum oligotrophic. It is widespread but local through papillosum and S. capillifolium are very common the lowlands of Wales, up to the Scottish Borders and S. tenellum is also a constant but less abun- and in south-west Scotland. There are also locali- dant. Sphagnum magellanicum is a preferential ties in southern England and east Scotland. species and a major peat-builder. S. imbricatum is Erica tetralix – Sphagnum papillosum raised a distinctive species where present. Over gently- and blanket mire vegetation is a climax of a undulating surfaces the Sphagnum spp. form an hydroseral succession. However, the typical habi- irregular patchwork, but with increasing differen- tat of this community has been widely affected by tiation of hummocks and hollows they show a ver- various treatments, notably peat-cutting, burning tical stratification. On hummock tops and sides and grazing, and these have often modified the S. capillifolium is abundant, and S. papillosum, vegetation or reduced it to fragmentary stands.

42 M18

Sphagnum spp. luxuriant, Sphagnum spp. abundant, with Sphagnum magellan- with Sphagnum capillifolium icum frequent and abundant, usually dominant, S. papillo- along with S. papillosum in sum frequent but usually wetter lawns. Narthecium subordinate and S. magellan- ossifragum and Drosera icum only occasional. rotundifolia common and Narthecium ossifragum and Vaccinium oxycoccos and Vaccinium oxycoccos occa- Andromeda polifolia sional and Drosera rotundifo- especially distinctive. lia and Andromeda polifolia very scarce. Sub-shrubs often quite vigorous. Cladonia species frequent and locally abundant.

M18a M18b

Sphagnum magellanicum – Empetrum nigrum ssp. nigrum – Andromeda polifolia sub-community Cladonia spp. sub-community

All the community vascular constants Calluna vulgaris, Scirpus cespitosus are of high frequency but very often and Eriophorum vaginatum tend to none is dominant. Sphagnum spp. have higher covers here, Calluna form an obvious and extensive carpet vulgaris in particular becoming more in which Sphagnum papillosum, often vigorous and abundant. Empetrum with abundant S. magellanicum, pre- nigrum is also frequent among dominates along with the constants them. Among the Sphagnum spp., S. tenellum and S. capillifolium. S. capillifolium is strongly dominant, Scattered through are frequent although S. papillosum is still individuals of Drosera rotundifolia frequent. S. tenellum is patchy and and Narthecium ossifragum with the S. magellanicum only occasional. preferentials Vaccinium oxycoccos and Other mosses become frequent, Andromeda polifolia. Cladonia spp. with Pleurozium schreberi and and Pleurozium schreberi are typically Rhytidiadelphus loreus being good of low frequency. preferentials; a range of hepatics is also common. There is a marked increase This sub-community occurs throughout in Cladonia spp., notably Cladonia the range of M18. impexa, C. uncialis and C. arbuscula, each of which can be locally abundant. This sub-community occurs throughout the range of M18.

43 M19 Calluna vulgaris – Eriophorum comium splendens is common at higher altitudes. vaginatum blanket mire A variety of leafy hepatics occur in this community and lichens are frequent. Larger This vegetation is generally dominated by Cladonia spp. can be abundant on old Eriophorum mixtures of Eriophorum vaginatum and ericoid hummocks. sub-shrubs. Sphagnum spp. can be prominent This mire is the typical blanket bog vegetation over wetter ground but are not as luxuriant or rich of high-altitude ombrogenous peats present in as in Scirpus cespitosus – Eriophorum vaginatum the wet and cold climate of the uplands of north- blanket mire (M17) or Erica tetralix – Sphagnum ern Britain. In particular, it occurs on high-level papillosum raised and blanket mire (M18). The plateaux and broad watersheds, usually above ground surface is often uneven, but does not show 300 m, and is confined to deeper peats, usually true hummock and hollow relief. Eriophorum more than 2 m thick, on flat or gently-sloping vaginatum is abundant and at least co-dominant. ground. The peats are usually well-humified, Normally this community has very frequent highly acidic with a surface pH often less than 4. occurrences of Calluna vulgaris, Vaccinium They are not consistently waterlogged and may myrtillus and Empetrum nigrum ssp. nigrum and, become surface oxidised in summer. Erosion of at higher altitudes, V. vitis-idaea, V. uliginosum the peat is common. This community is found on and E. nigrum ssp. hermaphroditum. Overall the higher ground in the Pennines, the central Calluna is the most common co-dominant along Highlands of Scotland, and Wales. with Eriophorum vaginatum, but diverse mixtures Treatments such as burning and grazing are of these sub-shrubs are very frequent. Vascular important in influencing the composition and associates are few, the commonest being structure of the vegetation throughout the range of Eriophorum angustifolium, and Rubus chamae- this community, in particular where stands form morus,a species which is distinctive for this com- part of unenclosed hill grazing or grouse moors. munity. Deschampsia flexuosa and Juncus squar- A stable diversity of bog vegetation can be rosus occur occasionally throughout, and at high- maintained by careful burning on a rotation of er altitudes Carex bigelowii becomes frequent. around 10 years, or by moderate levels of grazing. In contrast to the vascular plants, the bryophyte However, frequent burning or heavy grazing flora is rich, often with a cover exceeding 50%. contribute to the conversion of the Calluna vul- The most frequent Sphagnum species is S. capilli- garis – Eriophorum vaginatum blanket mire to folium, which forms patches rather than carpets. Eriophorum vaginatum blanket mire (M20). In Hypnaceous mosses are consistently present and other cases drainage can convert this community Pleurozium schreberi, Rhytidiadelphus loreus, into heathland or grassland, and this type of blan- Hypnum cupressiforme/jutlandicum and Plagio- ket mire has been reclaimed for agriculture or thecium undulatum are all very frequent. Hylo- forestry in many areas.

44 spp. Carex , and Calluna is less com- Ptilidium ciliare. and Eriophorum is very frequent. Calluna Empetrum nigrum constant and common in and and Hylocomium splendens – M19c These are mixed with other and the more restricted pres- hermaphroditum occurs quite often, as do myrtillus ssp. V. Scirpus cespitosus. Sphagnum , uliginosum. Rubus chamaemorus

and V. accinium vitis-idaea vaginatum. Hylocomium splendens Racomitrium lanuginosum Polytrichum alpestre the ground layer. Empetrum V often co-dominant with vulgaris hermaphroditum accinium vitis-idaea V accinium vitis-idaea bigelowii can be quite prominent, with a range of other bryophytes including the hepatic The lichen flora is usually well developed. This sub-community extends to the altitudinal limit of this kind blanket bog in central Scotland. Three variants. V sub-community This embraces all the high-montane blanket mire. It preserves all the general floristic features but is distinctive in the frequent and consistent presence of ssp. ence of sub-shrubs and usually with abundant vulgaris. Eriophorum angustifolium mon, but Juncus squarrosus Rubus rare and frequent. cover patchy. Eriophorum vaginatum usually abundant and chamaemorus Scirpus cespitosus Sphagnum , Rubus Empetrum Carex Molinia also nigrum is usually ssp. and and uliginosum is very scarce occasional

and/or particularly V. Calluna vulgaris ssp. , flora is impover- M19b however increases great- rare. Bryophytes in as a replacement. M19 nigrum have a low frequency. have a low frequency. Erica tetralix ssp. Sphagnum accinium vitis-idaea at most and often with ssp. nigrum V occasional and Juncus squarrosus Empetrum nigrum hermaphroditum bigelowii M19c rare. Scirpus cespitosus accinium myrtillus Empetrum nigrum sub-community This sub-community preserves all the features of M19 although it is very variable in all its structural elements. Eriophorum vaginatum abundant, with sub-shrubs playing a consistent role and being the leading species, though V nigrum and chamaemorus The ly. ished and on drier ground hypnaceous mosses are particularly abundant. This forms the richer type of ‘Pennine blanket bog’ extending northwards through Cheviot and the Borders into eastern Scotland. caerulea the latter, can increase greatly after the latter, burning. being ssp. less Rubus Scirpus Sphagnum can be co- is preferential is distinctive. rare. is frequent and Calluna vulgaris M19a frequent. Erica tetralix S. capillifolium sub-community spp. tend to be consistently Empetrum nigrum Erica tetralix . chamaemorus spp. cover quite extensive. Eriophorum vaginatum cespitosus abundant, more common and is often the predominant sub-shrub with some dominant with the sub-shrubs though generally less abundant than in other sub-communities. Erica tetralix Eriophorum vaginatum nigrum and sometimes with high cover. Scirpus cespitosus locally abundant. The infrequency of Rubus chamaemorus Sphagnum abundant with commonly accompanied by S. papillosum. This is the usual form found at lower altitudes that have a rather more oceanic climate, such as in Wales and south-west Scotland.

45 M20 Eriophorum vaginatum Bulkier species like Cladonia arbuscula, C. uncialis and C. impexa can sometimes be found blanket and raised mire or sometimes there is just a patchy cover of peat encrusters. Eriophorum vaginatum mire comprises species- This community is characteristic of ombroge- poor ombrogenous bog vegetation dominated by nous peats on bogs where certain treatments have E. vaginatum, the tussocks of which form an open greatly affected the vegetation; grazing and burn- or closed canopy 10-30 cm high. The only other ing have been of greatest significance, but draining constant plant is E. angustifolium, which is usually and aerial pollution have also played a part. It is found as scattered shoots. Ericoid sub-shrubs are commonest on blanket mires, where these factors patchy; Calluna vulgaris, Empetrum nigrum ssp. have contributed both to floristic impoverishment nigrum and Vaccinium myrtillus can each be and to gross erosion of the peats, but is also found found quite frequently and the last two may be locally on run-down raised bogs. The Eriophorum locally abundant. Alternatively these species may mire is present mainly between 500 m and 700 m be reduced to sparse shoots. Deschampsia flexu- where the climate is cold and wet. The peats are osa is fairly common while Festuca ovina, Juncus generally dry, often showing surface oxidation and squarrosus, Scirpus cespitosus and Carex bigel- with a pH frequently as low as 3. This community owii are all infrequent. can be found locally through northern Britain, and Bryophytes are sparse and patchy. Sphagnum is especially extensive in the southern Pennines. spp. are scarce with Sphagnum capillifolium and This community has been seen to revert to the veg- S. papillosum the most usual species. Hypnaceous etation characteristic of the richer blanket bog mosses are poorly represented; the only moss of community Calluna vulgaris – Eriophorum vagi- any frequency being Campylopus paradoxus natum mire (M19) within 25 years of enclosure which can be accompanied by Dicranum scopari- and freedom from burning, but in many instances, um. There may be occasional shoots of Ortho- particularly if intensive grazing or frequent burn- dontium lineare, Pohlia nutans and Drepa- ing have been accompanied by drainage, the nocladus fluitans. A variety of leafy hepatics may degeneration of the vegetation is perhaps be present. Lichens are typically few in number. irreversible.

M20

Calluna vulgaris, Vaccinium myr- Sub-shrubs at most occasional and tillus and Empetrum ssp. nigrum sparse among abundant Eriophorum occur frequently. Campylopus para- vaginatum with an impoverished doxus and Dicranum scoparium bryophyte and lichen flora. also frequent with occasional patches of peat-encrusting lichens.

M20b M20a

Calluna vulgaris – Cladonia spp. Species-poor sub-community sub-community Eriophorum vaginatum forms the Eriophorum vaginatum not com- main vascular bulk, with only scat- pletely dominant though, together tered E. angustifolium, occasional with E. angustifolium, it is the most sub-shrubs and sometimes a little frequent species. Sub-shrubs scat- Deschampsia flexuosa. Ground pre- tered, sometimes showing local dominantly bare with scattered dominance. Bryophytes frequent tufts of Campylopus paradoxus, but in small amounts. Larger Orthodontium lineare and Cladonia spp. among shrub stools Calypogeia spp. Lichens and old Eriophorum tussocks. typically very sparse.

46 M21 Narthecium ossifragum – Narthecium ossifragum are constant and often abundant. Molinia caerulea is typical, but is often Sphagnum papillosum valley mire weak and not tussock-forming, and Rhynchospora alba is characteristic of one sub-community, being This mire vegetation is dominated by carpets of most prominent around hollows and pools. The Sphagnum spp. with scattered herbs and sub- sub-shrubs Erica tetralix and Calluna vulgaris shrubs forming extensive lawns or the drier parts are very frequent, forming an open canopy. of hummock and hollow complexes. The domi- More restricted but conspicuous when present is nant Sphagnum is usually S. papillosum. Sphag- Myrica gale. Other plants are generally present as num auriculatum or S. recurvum (and occasional- scattered individuals, Drosera rotundifolia being ly both) are frequently encountered and less often the most frequent. S. cuspidatum. Locally, S. magellanicum and S. This is a community of permanently water- pulchrum may be present. Sphagnum compactum logged, acid and oligotrophic peats, especially is almost always absent in contrast with Erica characteristic of valley mires maintained by a tetralix – Sphagnum compactum wet heath (M16). locally high water table. The peat on which this Only a few other mosses occur and they are gener- community is found is usually not very deep (20- ally of low cover, but leafy hepatics are common. 150 cm) with a surface pH mostly in the range of Odontoschisma sphagni and Kurzia pauciflora 3.5-4.5, and a water table at or very close to the are most common, but Cladopodiella fluitans, surface. It is found locally in the southern low- Cephalozia macrostachya, C. connivens, C. bicus- lands of Britain. pidata and Calypogeia fissa have also been record- Neither burning nor grazing are important in ed. Lichens are typically sparse, but hummock maintaining this community, as the wetness of the tops can be a habitat for Cladonia impexa, vegetation gives its some protection from these C. arbuscula and C. uncialis. treatments, but both can cause damage if com- The vascular plant species present provide the bined with drainage. With continued autogenic major distinction between this community and accumulation of peat, it would probably progress other types of Erico – Sphagnion bogs (M17-M20). naturally to some kind of woodland but this Eriophorum vaginatum and Scirpus cespitosus process is likely to be very slow in the absence of are rare, but Eriophorum angustifolium and drainage.

M21

Rhynchospora alba very frequent Rhynchospora alba and Myrica gale and Myrica gale occasional, rather infrequent, but Vaccinium sometimes abundant in the oxycoccos patchily present and Sphagnum carpet, which is Potentilla erecta occasional in a usually dominated by mixtures of carpet usually dominated by S. papillosum and S. auriculatum, Sphagnum recurvum with some with S. recurvum scarce. S. papillosum but little S. auriculatum.

M21a M21b

Rynchospora alba – Sphagnum Vaccinium oxycoccos – Sphagnum auriculatum sub-community recurvum sub-community

In this, the most frequently Sphagnum papillosum is often described M21 community, the abundant but somewhat patchy Sphagnum carpet is generally and S. recurvum frequently has dominated by mixtures of an equal cover. S. auriculatum S. papillosum and S. auriculatum. is much reduced in frequency. Hepatics are varied and often Odontoschisma sphagni occurs abundant. All vascular constants sometimes but hepatics are greatly have a high frequency and in addi- reduced. Among vascular plants tion Rhynchospora alba is very Rhynchospora alba is scarce and frequent. Myrica gale frequently Vaccinium oxycoccos reduced in shows local abundance. frequency. This sub-community is best This sub-community extends into represented in central southern the north and west of England and England. Wales.

47 M22 Juncus subnodulosus – Mentha aquatica, Caltha palustris, Equisetum palustre, Carex panicea, Valeriana dioica, Hyper- Cirsium palustre fen-meadow icum tetrapterum, Hydrocotyle vulgaris, Lotus uliginosus, Lychnis flos-cuculi, Cardamine praten- This community shows considerable variation in sis, Ranunculus acris, Potentilla erecta, Cerastium its floristic composition which often reflects a fontanum, and Rumex acetosa, with several unique and complex history of mowing and scrambling plants including Galium uliginosum, grazing management. The most prominent struc- G. palustre, Vicia cracca and Lathyrus pratensis. tural element typically consists of rushes and Bryophytes play a reduced role with only sedges of moderate stature, appearing as a rank Calliergon cuspidatum and Brachythecium rutab- sward if it is not grazed. Juncus subnodulosus is ulum being common throughout. the most important of the bulkier species and the This community brings together secondary most usual dominant. Juncus inflexus and J. artic- herbaceous vegetation developed over a variety of ulatus are the commonest accompanying rushes. moist, base-rich and moderately mesotrophic Of the sedges, the most striking are Carex acuti- peats in southern lowland Britain. It can be found formis and C. disticha, either of which can be fre- either in, or around, well-developed springs, quent or occasionally dominant. Much more occa- flushes and mires, or marking out more ill-defined sionally C. elata or C. paniculata can occur. In areas of influence of surface or ground waters. summer this rush and sedge layer can be This community marks out soils which are kept overtopped by flowering dicotyledons. The most moist for most of the year and have a moderate to frequent of these throughout the community are high base-status, and usually a pH range of 6.5-7.5. Cirsium palustre, Filipendula ulmaria, Angelica The community has a wide distribution through sylvestris, Succisa pratensis, Eupatorium canna- the southern British lowlands with particular con- binum and Scrophularia aquatica. More locally centrations of stands in East Anglia, north Lythrum salicaria, Lysimachia vulgaris, Valeriana Buckinghamshire and Anglesey. officinalis, Thalictrum flavum and Symphytum This community is always dependent on vari- officinale can be found, and, in Broadland, the ous kinds of treatment for its maintenance, as it is nationally rare Peucedanum palustre. However, derived from other wetland vegetation types by grazing may keep these species severely in check. mowing or grazing, or both. The reduction in graz- Among smaller species, grasses are important, ing results in the expansion of bulky dominants and species found include Holcus lanatus, and ranker grasses and the overwhelming of the Festuca rubra and, less commonly, Arrhena- smaller herbs. Its overall distribution and the therum elatius, together with Poa trivialis, extent of the stands has become much less than Agrostis stolonifera, Anthoxanthum odoratum formerly because of intensive land improvement and Briza media. Smaller herbs are those charac- and abandonment of traditional agricultural teristic of moist grasslands, the commonest being practices.

48 , , and , Plantago and , patchily Carex dis- rifolium T Centaurea Cardamine Caltha , Angelica Lotus , aleriana dioica , Briza media V , Cirsium ; also , Prunella vulgaris The lower sward is common at low and occasionally spp. sub-community Dactylorhiza fuchsii. often accompanied by riglochin palustre . There is a variety of is generally scarce. M22b T Rumex acetosa anserina and Hypericum ,

and , show an increased P. rifolium , Epilobium parviflorum. T J. articulatus – C. flacca ychnis flos-cuculi which are characteristic of M22 as L Molinia caerulea and Carex panicea and Eupatorium cannabinum Cerastium fontanum pratense , Rumex acetosa. Deschampsia cespitosa Ranunculus acris

Filipendula ulmaria , , , and , T. , and and aller dicotyledons such as tetrapterum a whole. Strongly preferential are the species listed above together with Ranunculus repens Rhinanthus minor Phragmites australis This sub-community is most frequently developed around grazed spring-fens and wet field hollows and occurs through the range of M22. Potentilla erecta repens lanceolata palustris abundant. Anthoxanthum odoratum cover with frequent records for pratensis sylvestris nigra Succisa pratensis frequency and often occur with other herbs; most frequent are uliginosus Juncus subnodulosus J. inflexus ticha Briza media In comparison to M22a, in this sub-community the rush and sedge tier has a lower cover density and there is a richer associated flora. T palustre particularly rich. There is a range of grasses, often with C. nigra , and Cirsium Angelica , and and Holcus Species listed opposite at most occasional and hardly ever abundant. . There are Poa trivialis sometimes ithin this general , usually dominant W and Juncus subnodulosus M22a , mat-formers such as Mentha aquatica Molinia caerulea Succisa pratensis Filipendula ulmaria , Festuca rubra , , ypical sub-community sylvestris Molinia caerulea Agrostis stolonifera and taller dicotyledons such as palustre Eupatorium cannabinum also sprawling plants and a few shorter species such as Equisetum palustre. lanatus T In this, the most common kind of there are no preferential fen-meadow, floristic features and the general impression is of rank structure and impoverishment. is frequent and the commonest dominant. The commonest associates are bulkier grasses such as framework there is considerable local variation. This sub-community is the most frequent type of spring-fed stands. Juncus subnodulosus in rather rank and impoverished vegetation with bulkier grasses abundant. dicotyledons listed opposite infrequent at most. M22 , and are Angelica , , but with Potentilla , aleriana are all frequent. V Cirsium , usually dominant is dominant, but are often present sub-community are sub-community M22d Iris pseudacorus are sometimes Carex elata Succisa pratensis Equisetum fluviatile Carex ysimachia vulgaris Phragmites australis is occasional and tussocks L , and Filipendula ulmaria and , common, Thalictrum flavum Menyanthes trifoliata C. paniculata frequent, with especially well-represented on topogenous mires in East Anglia. sylvestris This and the and all common and officinalis Ranunculus flammula prominent. Tall dicotyledons are prominent. Tall prominent in summer; palustre with little or no frequent and sometimes abundant C. acutiformis. Galium palustre common but other associates listed opposite rare. as in M22c, Hydrocotyle vulgaris and Juncus subnodulosus Iris pseudacorus Juncus subnodulosus palustris occasional. Grasses and smaller herbs characteristic of M22b are sparse. Carex elata of ythrum salicaria L C. elata , or , , , Hydrocotyle vulgaris . Grasses Menyanthes , is often Phragmites australis and Carex acutiformis sometimes abundant. Juncus subnodulo- . The plants listed Equisetum , Juncus subnodulosus M22c sub-community are Potentilla palustris Berula erecta Dactylorhiza incarnata. Iris sub-community is uncommon in fen- constant and sometimes Ranunculus flammula and and , Pedicularis palustris especially well-represented on topogenous mires in East Anglia. R. lingua and smaller herbs of M22b are particularly sparse. This and the Carex elata Carex elata meadow vegetation but here it occurs with some abundance and occasionally is co-dominant with sus. Phragmites australis present and there is usually some Hydrocotyle vulgaris trifoliata above are preferential. Some stands have Carex elata abundant among with frequent Epilobium palustre fluviatile

49 M23 Juncus effusus/acutiflorus – Hydrocotyle vulgaris, Viola palustris, and Stellaria alsine. Galium palustre rush-pasture Bryophytes are variable in their cover. Where the vegetation is open they may be abundant. This vegetation is ill-defined and characterised by Calliergon cuspidatum is the most frequent, often the abundance of either Juncus effusus or J. acuti- occurring with Brachythecium rutabulum and florus, sometimes both, in a ground of mesophytic Rhytidiadelphus squarrosus. herbs common in moist agricultural grassland. This rush-pasture occurs over a variety of The rushes often have a high cover but they may moist, moderately acid to neutral, peaty and min- also be more sparse. Juncus effusus is more abun- eral soils in the cool and rainy lowlands of west- dant in the east, while J. acutiflorus has a distinct- ern Britain. It is a community of gently-sloping ly western distribution. Diversity in dominants is ground around the margins of soligenous flushes, not great but the associates are quite diverse, mak- as a zone around topogenous mires and wet ing the bounds of this vegetation type hard to fix. heaths, and especially widespread in ill-drained, Sometimes J. articulatus may be locally frequent comparatively unimproved or reverted pasture. It and abundant. Holcus lanatus is the most frequent can be found on a variety of moderately acid to grass, but Agrostis canina ssp. canina, A. stolon- neutral soils that are kept moist to wet for most of ifera, Anthoxanthum odoratum and Poa trivialis the year with a pH in the range of 4-6. It is found are also common in drier stands. Festuca rubra at the opposite climatic and edaphic extreme to and Agrostis capillaris may also become frequent. the Juncus subnodulosus – Cirsium palustre fen Molinia caerulea is increasingly common and meadow (M22) with a distinctly oceanic distribu- abundant towards the west and there may be some tion. The community is wide-spread through the sedges in the sward. There is a variety of common west of Britain from Devon and Cornwall to Skye herbs. Among the taller species Cirsium palustre and Caithness. is the commonest, Rumex acetosa, Angelica This community is maintained mainly by graz- sylvestris and Epilobium palustre are frequent, ing and more occasionally mowing which pre- and two sprawling species Galium palustre and vents the succession of the community to wood- Lotus uliginosus are constant. Frequent smaller land. Draining and other kinds of soil improve- species are Mentha aquatica, Ranunculus flam- ments such as fertilising and reseeding have mula, R. repens, R. acris, Cardamine pratensis, reduced its former extent.

50 M23

Juncus effusus very common, but Juncus effusus constant and usually exceeded by J. acutiflorus, with dominant, with J. acutiflorus Molinia caerulea and Holcus scarce. Holcus lanatus common, lanatus frequent and sometimes but Molinia caerulea and abundant. Filipendula ulmaria dicotyledons listed opposite occasional, also some of all scarce. Ranunculus acris, Potentilla erecta, Achillea ptarmica and Equisetum palustre and locally prominent tall-fen herbs such as Lythrum salicaria and Iris pseudacorus.

M23a M23b

Juncus acutiflorus sub-community Juncus effusus sub-community

Juncus acutiflorus and J. effusus This sub-community is less are both constant, J. articulatus well-defined and is essentially a is locally prominent and J. con- transition between M23a and the glomeratus is occasional. The com- Holcus lanatus – Juncus effusus monest grasses are Holcus lanatus rush-pasture (MG10). Other rushes and, preferential here, Molinia comprise Juncus articulatus and caerulea. Community herbs such as J. conglomeratus, but J. inflexus, Cirsium palustre, Rumex acetosa common in MG10, is absent. and Angelica sylvestris remain fre- Molinia caerulea is infrequent, quent with Galium palustre and but grasses are important in the Lotus uliginosus. Filipendula sward. Where the community is ulmaria is more common than in surrounded by improved pasture, M23b and there may be an abun- as is common, Cynosurus cristatus dance of taller herbs. In the lower and Lolium perenne can be present tier of vegetation, Mentha aquatica, at low cover. Good distinguishing Cardamine pratensis, Ranunculus features are the high frequencies of flammula and R. repens are Galium palustre, Cirsium palustre, frequent with at least some of Ranunculus flammula and Mentha the herbs listed above. aquatica. This, the more sharply-defined This is the typical sub-community sub-community, prevails in of the South-West Peninsula, but Scotland and is common in Wales. is also found through the range of M23.

51 M24 Molinia caerulea – Cirsium Mentha aquatica, Prunella vulgaris, Ranunculus acris, Hydrocotyle vulgaris, and the scramblers dissectum fen-meadow Vicia cracca and Lathyrus pratensis. Coarser grasses are often prominent, with This community includes the bulk of the Molinia Holcus lanatus and Anthoxanthum odoratum caerulea vegetation in the lowland south-east of most frequent and Festuca rubra, Deschampsia Britain. Molinia is always the dominant to the cespitosa and Agrostis stolonifera less common, extent that associates may be reduced to scattered though sometimes abundant. There can also be individuals of only a few species. Often however some sedges present, the most common being there are a considerable number of associates. In smaller species such as Carex panicea, which is a structural terms the most important species are community constant, and less frequent C. hostiana other monocotyledons. Through most of the and C. pulicaris. Bryophytes are generally few and central and eastern part of the range where this of low cover. community is often found in association with This is a community of moist to fairly dry peats fens, Juncus subnodulosus is the characteristic and peaty mineral soils which are circumneutral, rush with J. articulatus and J. inflexus sometimes generally having a pH within the range 5-6.5. It also present. To the south and west where the can be found in association with both soligenous community often develops among heath vegeta- and topogenous mires, typically marking out the tion, J. acutiflorus and J. conglomeratus become better-drained fringes of bogs and fens, or the mar- frequent. gins of wet hollows and flushes. This community The associated flora of dicotyledons helps to is widespread through the lowland south of distinguish this community, although it is often Britain but has become increasingly local with difficult to separate it from Juncus subnodulosus – changes in agricultural practice. Cirsium palustre fen meadow (M22) and Juncus Although climate and soil together both effusus/acutiflorus – Galium palustre rush pasture influence the floristics of this community it is (M23) when these contain Molinia. Cirsium palus- essentially a secondary vegetation type, derived tre and Angelica sylvestris are both very frequent from a variety of wetland vegetation types and and Filipendula ulmaria and Centaurea nigra maintained by mowing or grazing. In the can also be common. More strictly limited are absence of any kind of treatment all the stands of Valeriana dioica, Succisa pratensis, and Cirsium the community would probably progress to dissectum, although only the last species is pref- scrub or woodland. It has been reduced in extent erential. Other common species of wide occur- by agricultural reclamation. Other stands have rence are Potentilla erecta, Lotus uliginosus, become rank and scrubby with neglect.

52 and Carex J. con- and Erica and Galium , Calluna vul- absent, but Erica tetralix and the tall-fen , so that the vegeta- are intermixed with occasional. Species – J. conglomeratus Centaurea nigra with frequent M24c , Anthoxanthum odora- Festuca rubra , and Dactylorhiza maculata , less often . There is frequently some J. effusus Ulex gallii and and a range of small herbs. Calluna vulgaris Juncus acutiflorus , and , less often aleriana dioica Juncus acutiflorus sub-community Rushes are a common feature, most usually glomeratus Erica tetralix garis tion looks more like a heath. However Holcus lanatus tum Agrostis stolonifera Molinia caerulea panicea V Filipendula ulmaria herbs of M24a are not represented. Bryophytes are not conspicuous, though a number of species have been recorded. This is the most usual type of M24 in south-western Britain. Juncus subnodulosus J. acutiflorus common, listed opposite all scarce but tetralix palustre frequent. M24 and espe- Succisa Carex C. palus- , preferential are all very are frequent and showing a ythrum L only occasional. C. pulicaris Smaller grasses are Juncus subnodulo- C. nigra and Holcus lanatus is often found with M24b is strongly preferen- , C. hostiana Cirsium dissectum usually absent. , and Angelica sylvestris J. articulatus. , Briza media or and common ypical sub-community common together with the species list- ed above. Sub-shrubs are typically sparse and bryophytes are poorly represented. This is the most common sub-commu- nity in central and eastern England. tre Eupatorium cannabinum Phragmites australis Cladium mariscus salicaria T Molinia caerulea smaller amounts of sus well represented; Anthoxanthum odoratum and tial. Sedges are common with panicea peak of occurrence, and sometimes in abundance. pratensis cially frequent and and icia cracca Galium uliginosum generally dominant V , , Juncus subnodulosus , and which Phragmites aleriana dioica Molinia caerulea with and frequent records for some of V Filipendula ulmaria Equisetum palustre. Centaurea nigra Succisa Equisetum constant, are also common quite common, ythrum salicaria ythrum salicaria L L M24a and Campylium stellatum and Cirsium dissectum The best single preferential Angelica sylvestris , increase in frequency. increase in frequency. . , Calliergon cuspidatum ysimachia vulgaris. Cirsium L Brachythecium rutabulum Molinia caerulea. Eupatorium Eupatorium cannabinum Phragmites australis Cladium mariscus both typically subordinate in cover to cannabinum frequent. australis is provides continuity with tall-herb fen; less common are and palustre Filipendula ulmaria and, as reed or sedge cover becomes plants such as thinner, pratensis Centaurea nigra palustre Bryophytes can be more conspicuous but species are in this sub-community, with only few, joining and as a distinctive preferential. This sub-community is mainly confined to East Anglia. Eupatorium cannabinum sub-community One of the most conspicuous species here, even when sparse, is

53 M25 Molinia caerulea – frequency throughout and Holcus lanatus is fairly Potentilla erecta mire common. Among the dense herbage, bryophytes are sparse. Molinia caerulea is the most abundant species This mire is a community of moist, but well- found in this community The associated flora is aerated, acid to neutral peats and peaty mineral poor, and most common are rushes and a few soils in the wet and cool western lowlands of dicotyledons. Among the former, Juncus Britain. It occurs over gently-sloping ground, acutiflorus and J. effusus are the most frequent. marking out seepage zones and flushed margins Juncus articulatus and J. subnodulosus are both of sluggish streams, water-tracks and topogenous occasional, and J. conglomeratus is very scarce. mires, but also extends onto the fringes of The only constant dicotyledon is Potentilla erecta. ombrogenous mires. Soil and drainage conditions Lotus uliginosus, Succisa pratensis, Cirsium of this community have similarities to those of palustre and Angelica sylvestris are sparse and M23 and M24 and geographically this communi- occasionally there can be some Eupatorium ty can be seen as a northern/western replacement cannabinum or Filipendula ulmaria. Cirsium dis- of M24. It is especially frequent in south-west sectum is very rare and its presence separates the England, Wales, and southern Scotland. Molinia caerulea – Cirsium dissectum mire (M24) Although both climate and soils influence the from this community. Also, since the soil pH is composition of the vegetation, treatments such as generally acidic, plants such as Carex hostiana, burning, grazing and drainage are likely to be C. pulicaris and Briza media, frequent in M24, are largely responsible for the development of this of very limited occurrence here. Occasionally sub- community over ground that would naturally shrubs can be quite common, particularly Calluna carry some other kind of mire or wet heath vegeta- vulgaris and Erica tetralix. Ulex gallii can also be tion. Tracts of this community have been replaced occasional in Wales and south-west England, and by coniferous plantations, particularly in the U. europaea occurs in some stands. Myrica gale is upland fringes of the north-west. Elsewhere in the local but can be quite extensive and dense. lowlands, other tracts of the community together Grasses are limited in importance but Agrostis with neighbouring vegetation have been lost to canina and A. stolonifera can be found at low agricultural improvements.

54 , and , and Mentha and Molinia and Centaurea and rush Angelica Mentha aquatica and Eupatorium sub-community with frequent , Bryophytes are again M25c are notable together and Schoenus nigricans Pulicaria dysenterica Cirsium palustre. Filipendula ulmaria form scattered patches. , aller dicotyledons are Calliergon cuspidatum Juncus acutiflorus T Succisa pratensis Cardamine pratensis and is vigorous, but variegated by , Molinia caerulea Shorter species include ales. aleriana officinalis Species listed opposite usually all occasional but tall herbs prominent among clumps, with frequent sylvestris Epilobium palustre cannabinum Galium palustre are occasional. can be locally abundant. Angelica sylvestris This is the most local sub-community, but also the most striking sub- developed on moist ground community, with freedom from grazing. caerulea clumps of sparse but C. giganteum This sub-community is found mainly in south-west England and W Equisetum palustre Galium palustre. aquatica J. effusus. common: V nigra. Lotus uliginosus with the preferential species listed above and also are Lotus Luzula are very , , , is still Agrostis cap- , Rumex acetosa Calluna vulgaris and and occasionally Rubus fruticosus. Myrica gale M25 M25b Festuca rubra Calluna vulgaris Cirsium palustre L. campestris. Erica , are occasional, as and and Succisa pratensis and and Molinia caerulea patchily prominent in a rare but Danthonia decumbens , Ulex gallii are weakly preferential, but all tend to be grazed to rosettes. Smaller herbs and bryophytes are poorly represented. This sub-community is scattered throughout the range of M25 but is particularly frequent in Wales. all more frequent than in M25a and Serratula tinctoria is occasional. uncommon. uliginosus Juncus acutiflorus J. effusus grassy community with frequent Holcus lanatus tetralix Anthoxanthum odoratum sub-community Although dominant, the sward is shorter and more varied. Apart from the rushes and grasses mentioned above other associ- ates can be sparse. and U. europaeus Erica tetralix Anthoxanthum odoratum illaris multiflora and spp. com- , Agrostis wet heaths Bryophytes Hydrocotyle Calypogeia S. auricula- and quite frequent, is the dominant is strongly pref- Calluna Calluna vulgaris. and and and Sphagnum Aulacomnium Narthecium remains common but Anthoxanthum M25a Narthecium Erica tetralix sub-community constant, Myrica gale Eriophorum angustifolium. Drosera rotundifolia Drosera rotundifolia Festuca rubra , , Erica tetralix , Polytrichum commune iola palustris are sometimes present, but and , V , grasses are thin and taller herbs Molinia caerulea accinium oxycoccos. Eriophorum angustifolium all preferential. are the commonest species. V accinium oxycoccos. tum This sub-community can be found throughout the range of M25. and are distinctive, with palustre Hypnum jutlandicum fissa are noticeable, forming patches; Sphagnum recurvum Erica tetralix This is the widely distributed type of M25. canina are poorly represented. Among smaller plants, vulgaris with occasional ossifragum V but the associated flora is shifted towards that of (M15-16). is joined by Apart from sparse odoratum erential, with frequent Juncus acutiflorus with mon and occasional Erica tetralix vulgaris ossifragum

55 M26 Molinia caerulea – europaeus. Also common are Sanguisorba offici- Crepis paludosa mire nalis, Angelica sylvestris, Centaurea nigra, Leon- todon hispidus, Geum rivale and Lychnis flos- This community is well-defined by a block of cuculi. Less conspicuous, but also frequent, is constants and frequent companions but also Equisetum palustre. Potentilla erecta, Ranunculus shows considerable variation in associated flora. acris, and Anemone nemorosa are common. Stands range from swamp to those having a rank, Bryophytes are only prominent in exceptional grassy character. Molinia caerulea is almost cases, with Calliergon cuspidatum most frequent. always present, being the commonest dominant. This is a very local community of moist, Carex nigra is also a constant, often as prominent moderately base-rich and calcareous peats and tufts which can exceed Molinia in cover. Carex peaty mineral soils in the sub-montane northern panicea can be abundant and C. pulicaris is com- Pennines. It represents a northern and altitudinal mon. In stands transitional to swamp, C. approp- extreme of the richer kind of Molinia –tall herb inquata or C. rostrata are present. In the Festuca vegetation. Stands are rare but all occur around sub-community, by contrast, it is taller rushes and the northern Pennine uplands and the Lake grasses which, with Molinia, form the bulk of the District between 250 m and 450 m altitude. cover. Juncus acutiflorus may form dense patches This community is an apparently stable and J. conglomeratus and J. articulatus both occur component of topogenous sequences around open occasionally. waters and mires, but where it occurs on flushed Hemicryptophyte dicotyledons are an impor- slopes, grazing often maintains the community tant structural element among the Molinia, sedges and prevents progression of the community to and rushes. Most frequent are Succisa pratensis, scrub or woodland. Drainage and sward improve- Filipendula ulmaria, Valeriana dioica, Cirsium ment have probably destroyed many smaller palustre and Caltha palustris together with the stands of this community and contributed to its northern species Crepis paludosa and Trollius very local distribution.

56 M26

Molinia caerulea and Carex nigra both Carex nigra often subordinate to abundant, with locally prominent Molinia caerulea in more grassy or C. appropinquata or C. rostrata. rushy vegetation, with frequent and Sanguisorba officinalis, Angelica abundant Festuca rubra, F. ovina, sylvestris, Serratula tinctoria, Galium Holcus lanatus, Briza media, palustre and G. uliginosum all frequent; Deschampsia cespitosa, Anthoxanthum bryophytes patchy. odoratum, Juncus acutiflorus and J. conglomeratus; associates listed opposite all occasional.

M26a M26b

Sanguisorba officinalis Festuca rubra sub-community sub-community This sub-community appears more This is generally the less species-rich grassy and is usually developed on sub-community. Molinia caerulea drier soils. Molinia caerulea is the and Carex nigra are usually the most usual dominant, forming the bulk of a abundant plants, with one or both rough sward together with the grasses dominant in a swamp vegetation with listed above. Sedges are also common; large sedges as above. Smaller sedges Carex nigra and C. panicea can both can also occur, Carex panicea and show high cover and C. flacca C. pulicaris being common. Apart from and C. pulicaris can be frequent. Agrostis stolonifera, grasses are poorly Rushes are also common; Juncus represented and among small herbs acutiflorus and J. conglomeratus only Potentilla erecta, Ranunculus are preferential and J. articulatus acris and Anemone nemorosa occur also occurs. Taller dicotyledons with any frequency. The most common remain frequent, although Sanguisorba tall herbs are listed above. Bryophytes officinalis, Angelica sylvestris and are patchy but better-developed than Serratula tinctoria are all scarce. Geum in M26b. Calliergon cuspidatum, rivale, Centaurea nigra and Leontodon Lophocolea bidentata s.l., Thuidium hispidus are more common than in M26a. tamariscinum and Campylium stella- In shorter swards, Prunella vulgaris, tum are frequent, with Ctenidium Plantago lanceolata and Trifolium molluscum, Plagiochila asplenioides, repens can be found. Bryophytes Campylium elodes and Aulacomnium are often poorly represented, but palustre being preferential. Calliergon cuspidatum, Pseudo- scleropodium purum and Lophocolea This sub-community is found most bidentata remain frequent. extensively at Sunbiggin and Malham Tarns. This sub-community has a scattered distribution through the dales along the upland fringes.

57 M27 Filipendula ulmaria – with Juncus effusus the most common. Molinia caerulea can also be found occasionally. Among Angelica sylvestris mire smaller dicotyledons there can be Ranunculus repens, Mentha aquatica, Lotus uliginosus, and Although Filipendula ulmaria is frequent and Caltha palustris with more occasional Ranun- locally abundant in a variety of vegetation types, culus acris, Cardamine pratensis, C. flexuosa, in this community it forms the overwhelming Potentilla anserina, and Polygonum hydropiper. dominant and the only constant. The dominants of Bryophytes are few in number and of low cover. other communities in which it occurs, tall helo- This community is typically found where moist, phytes, bulky sedges, rushes and rank grasses are, reasonably rich, circumneutral soils occur in if present, all subordinate in this community. In situations protected from grazing. It can be found in the deep shade cast by Filipendula only scattered both topogenous and soligenous mires and is espe- individuals or dispersed clumps of other species cially typical of silted margins of slow-moving are found. The commonest accompanying tall streams and soakways, the edges of flushes and herbs are Angelica sylvestris, Valeriana officinalis damp hollows, and also of artificial habitats such as and Rumex acetosa. In the Valeriana – Rumex along dykes and roadside ditches and around sub-community they are often accompanied by ponds. This community occurs throughout lowland Lychnis flos-cuculi, Succisa pratensis, Geum Britain. rivale and sprawling Galium palustre. In the Both draining and grazing have reduced the Urtica – Vicia sub-community these species are extent of this community to small remnants in more scarce and Urtica dioica is very common many places. The community cannot tolerate with Cirsium arvense, Epilobium hirsutum, any other than very light or sporadic grazing Eupatorium cannabinum and Vicia cracca. At low and so stands often only persist outside enclo- frequency throughout there can be scattered sures, and around unreclaimed mires and flush- Lythrum salicaria, Rumex crispus, R. sangui- es. For example, this community can be found neus, Epilobium palustre, Equisetum palustre, in wet field bottoms and edges that have been E. arvense and E. fluviatile. fenced off, and alongside streams and ditches There are few bulky monocotyledons; between pasture and boundaries. Progression to Phragmites australis can be common and Phalaris woodland, even in the absence of treatments arundinacea is found occasionally. Rushes are few such as grazing or mowing, appears to be slow.

58 are and and and aleriana and V Agrostis , can be , Molinia caerulea Iris pseudacorus Lotus uliginosus is still the most Holcus lanatus and J. acutiflorus occasional, with a and Holcus lanatus M27c quite common. occur occasionally. occur occasionally. are constant, and – and Juncus effusus Mentha aquatica Cirsium palustre , , Angelica sylvestris Oenanthe crocata prominent. The sub-community is western in distribution. both constant and Molinia caerulea range of other grasses. In some stands Mentha aquatica are frequent. In others and/or Rumex acetosa Of greater importance, rushes and grasses may have moderate abundance. Juncus effusus stolonifera officinalis Juncus effusus sub-community Filipendula ulmaria abundant species, but other tall herbs such as Lotus uliginosus Holcus lanatus Juncus acutiflorus occasional in ranker swards with Anthoxanthum odoratum Associates listed opposite at most occasional but , . and Cirsium and some and Eupatorium , ythrum salicaria Phragmites aus- L Galium aparine can be common; and a variety forming patches. , however, is very , however, Angelica sylvestris Epilobium hirsutum M27 icia cracca and are common. M27b V or scattered clumps of , become scarce or – and Centaurea nigra. aleriana officinalis V Urtica dioica and Urtica dioica icia cracca common, often with prominent V Arrhenatherum elatius Holcus lanatus rushes. Smaller herbs and bryophytes are few and sparse. This sub-community is found in central, southern and eastern Britain. Associates listed for M27a at most occasional, but sparse tralis clumps of Urtica dioica sub-community Filipendula ulmaria of tall herbs again provide the main structural element. Cirsium palustre are occasional, but others present in M27a, e.g. Rumex acetosa absent. common and is found with occasional Eupatorium cannabinum Epilobium hirsutum Scattered throughout can be arvense Phragmites australis alternatively there may be tussocks of The sprawling herbs and cannabinum , as and and , , and climbing hnis and and G. uligi- Lyc , , Rumex acetosa , preferential R. repens Rumex acetosa , – aleriana is abundant Bryophytes , both sometimes Succisa pratensis V Galium palustre , , Stellaria alsine Brachythecium are less common. M27a Caltha palustris is quite common and can and Angelica sylvestris are common among taller occasional to frequent Lathyrus pratensis Succisa pratensis Poa trivialis Menyanthes trifoliata the most common species. Rumex acetosa Galium palustre , , Cardamine flexuosa , and Geum rivale aleriana officinalis aleriana officinalis ychnis flos-cuculi or sprawling. below and nosum C. pratensis Geum rivale Ranunculus flammula R. acris associates, with flos-cuculi Angelica sylvestris officinalis V Ajuga reptans here, grasses and rushes are infrequent. Carex rostrata occur with sub-community Filipendula ulmaria and dominant. The vegetation may be but overall it is charac- species-poor, terised by a variety of associates. Most common are and Among smaller herbs can be the species listed above with the most common sprawling plant. Apart from rutabulum This sub-community is the usual form in northern England and southern and eastern Scotland. Potentilla palustris. are better developed in this sub- with community, V locally abundant, with L

59 M28 Iris pseudacorus – marsh transitions Atriplex prostrata and Matri- Filipendula ulmaria mire caria maritima may be frequent with Samolus valerandi, Oenanthe lachenalii and halophytic In its typical form this is a luxuriant and herbs. Bryophytes are few, with Eurhynchium species-rich community with Iris pseudacorus praelongum being the commonest throughout. more abundant than Oenanthe crocata, although This community is confined to moist, more both are constants, except in the far north of nutrient-rich soils along the oceanic seaboard of Scotland where O. crocata is not found. Other tall Britain. It is especially characteristic of the fresh- herbs are nearly always present, though only water seepage zone along the upper edge of salt- Lycopus europaeus, Rumex crispus and Scut- marshes in the sheltered sea-lochs of western ellaria galericulata are frequent throughout the Scotland. Other situations in which it occurs are community. Other species such as Rumex acetosa, over stabilised shingle down the west coast and Lychnis flos-cuculi, Angelica sylvestris, Valeriana in wetter hollows and flushes on raised beach officinalis, Cirsium palustre, C. arvense and Urtica platforms and gentle cliff slopes. The community dioica are often common and conspicuous but is the oceanic counterpart of the Filipendula preferential to particular sub-communities. ulmaria – Angelica sylvestris mire (M27) and is Rushes and grasses are frequently important. largely confined to the west coast of Britain. In Juncus effusus and J. acutiflorus are common, as particular it is found in west Scotland from are Poa trivialis and Agrostis stolonifera. There are Orkney and Shetland southwards, with scattered a variety of smaller dicotyledons. Some typically stands in south-west England and west Wales. occur as scattered plants, for example Ranunculus The community was probably once much more acris, Caltha palustris, Stellaria alsine, Mentha widespread in south-west England and west Wales aquatica and Hydrocotyle vulgaris, while Ranun- but it may have been largely destroyed in its salt- culus repens and Potentilla anserina form mats marsh habitat by human interference with the tran- with high local cover. On patches of wet and open sitional upper zones. The community, where it ground, annuals may be prolific, such as Poly- does occur, is often not heavily grazed and it gonum hydropiper, Montia fontana, and on cattle- appears to be a relatively stable vegetation type poached mud, Ranunculus sceleratus. On salt- with only a slow progression to scrub or woodland.

60 , com- and , Atriplex and is scarce and Samolus Rumex crispus riglochin T Samolus , , infrequent in and Atriplex prostrata – can be abundant, M28c The most common pref- Glaux maritima. Samolus valerandi Agrostis stolonifera sub-community Oenanthe lachenalii Iris pseudacorus and and , Filipendula ulmaria ycopus europaeus Groups of species opposite, and even Filipendula ulmaria rather open vegetation with prostrata mon and sporadic records for maritime plants. the most common, with valerandi Matricaria maritima Festuca rubra. erentials are plants tolerant of saline habitats, including maritima Atriplex prostrata valerandi Although Oenanthe crocata taller associates are generally lacking; even L are only present as scattered plants. Among smaller plants the commonest grasses are the , is still Cirsium replaces Elymus Agrostis remain fre- Arrhenatherum and , ycopus euro- Galium aparine and L Cirsium arvense Oenanthe crocata M28 and M28b Galium aparine – Iris pseudacorus Grasses are often conspicu- Dactylis glomerata. very common as patchy Galium aparine Scutellaria galericulata Urtica dioica Poa trivialis constant with Stellaria media and , and Filipendula ulmaria Urtica dioica Species listed opposite occasional at most, but elatius arvense repens and occasional to frequent only other common taller dicotyledons are stolonifera carpets interspersed with the other species listed above. Urtica dioica sub-community The vegetation here, although as tall and luxuriant as in M28a, is less species-rich. paeus dominant and both and quent, but apart from which can be abundant. Other taller species of M28a are occasional or scarce and G. palustre. ous with , , can be ychnis Caltha L Poa , Oenanthe , , forming Carex and Cirsium Holcus lana- , , Angelica J. acutiflorus , is generally a Galium palustre. Rumex crispus , M28a and/or aleriana officinalis V Elymus repens Filipendula ulmaria Ranunculus acris Festuca rubra , Lotus uliginosus Epilobium palustre and and Rumex acetosa , , and trailing and spp. sub-community spp. Among the taller herbs, Iris pseudacorus Anthoxanthum odoratum , ycopus europaeus pratensis scattered tussocks, and with otrubae tus sylvestris with the species listed above, all occur Common frequently to occasionally. grasses are constant and patchily abundant with frequent Juncus effusus Juncus This is the richest sub-community in which other dicotyledons, rushes and grasses form a consistent associated flora. clear dominant although both patchily abundant with the above Juncus L Scutellaria galericulata crocata palustre flos-cuculi Galium palustre. palustris

61 M29 Hypericum elodes – M30 Related vegetation of Potamogeton polygonifolius seasonally-inundated habitats soakway Other vegetation of the same type as Hypericum elodes – Potamogeton polygonifolius soakway This community has a very distinctive appear- (M29), and characteristic of similar, seasonally ance, typically consisting of low creeping or float- inundated habitats, with rather base-poor and ing mats of Hypericum elodes and Potamogeton only moderately enriched waters, has only been polygonifolius. Very often, unless the ground has poorly sampled. Some examples, lacking been badly trampled by grazing animals, these two Hypericum elodes but otherwise the same as constants are set in a carpet of submerged M29, may be regarded as impoverished stands of Sphagnum auriculatum, sometimes with S. cuspi- that community, though it must be noted that datum, S. palustre or S. recurvum. Other bryo- species such as Potamogeton polygonifolius, phytes are sparse but Polytrichum commune or Eriophorum angustifolium, Juncus bulbosus/ Aulacomnium palustre, and Drepanocladus exan- kochii and Sphagnum auriculatum also occur nulatus, D. revolvens, and Calliergon cuspidatum, with some frequency in bog-pool and poor-fen may be locally abundant. vegetation. Other vascular plants are scattered. Juncus There are also stands in which Eleocharis bulbosus and Ranunculus flammula are the only multicaulis is strongly dominant with little or no constants but Hydrocotyle vulgaris, Anagallis Hypericum elodes or Potamogeton polygonifolius; tenella, Drosera rotundifolia, Narthecium ossi- these look similar to the Eleocharitetum multi- fragum, and Galium palustre can all be caulis recorded from Eire and elsewhere in west- moderately frequent, along with sedges such as ern Europe. Deschampsia setacea is listed as a Carex demissa, C. echinata, C. panicea and characteristic species of such vegetation, and in C. nigra. There can also be sparse shoots or small Britain this rare species is typical of this type of patches of Molinia caerulea, Agrostis canina ssp. habitat. Scirpus fluitans can also be found domi- canina, Juncus articulatus, J. effusus, J. acuti- nating in swards which lack some of the florus, Eleocharis multicaulis, Eriophorum angus- typical plants of M29, and in the New Forest and tifolium and Rhynchospora alba. Carex rostrata Cornwall, Baldellia ranunculoides is a frequent can also be found in some stands. Two rare species and conspicuous component of low-growing associated with this community are Galium vegetation in seasonally wet pools. debile, in the New Forest, and the fern Pilularia All these vegetation types, along with M29, globulifera. have been grouped in the Hydrocotylo-Baldellion This community is characteristic of shallow alliance, comprising assemblages of mesotrophic soakways and pools in peats and peaty mineral to oligotrophic, and periodically fluctuating soils with fluctuating water levels, such as waters. seepages and runnels around mires and in heathland pools, at moderate altitudes. The water No sub-communities. is typically clear, still or gently-flowing, moder- ately acid to neutral, with a pH between 4 and 5.5, and probably quite oligotrophic. This vegetation is confined to the warm oceanic parts of Britain and extends in a well-defined zone from west Surrey through the New Forest to the South-West Peninsula and north through Wales to Galloway. It may well be found further north, following the distribution of Hypericum elodes. This soakway appears to be a stable vegetation type in the absence of nutrient enrichment. In situations where there is some nutrient enrich- ment, grazing and trampling may help continually set back any tendency to succession. Trampling by grazing animals can also play a part in keeping the vegetation open and varied, although heavy poaching can be deleterious to the Sphagnum carpet.

No sub-communities.

62 M31 Anthelia julacea – Saxifraga stellaris. Less frequent are Eriophorum Sphagnum auriculatum spring angustifolium, Carex bigelowii, C. nigra, Festuca vivipara, Agrostis canina, A. stolonifera, Juncus In this community Anthelia julacea forms bulbosus, Thalictrum alpinum, and Viola palustris. cushions up to a metre or more in thickness and This is a montane community typical of often several square metres in extent. Its associated flora skeletal mineral and organic soils kept more or is species-poor and vascular plants are sparse. less permanently wet by the trickling of acid Among other bryophytes, Sphagnum auriculatum, and oligotrophic waters, of pH 4.5-5.0, frequently Marsupella marginata and Scapania undulata are derived at higher altitudes from snow-melt. It all constant, the first of which can form prominent occurs at moderate to high altitudes, from about patches. Racomitrium lanuginosum and Philonotis 400 m to over 1000 m, marking out areas of less fontana are also frequent with occasional vigorous seepage among tracts of montane grass- Calliergon sarmentosum, Campylopus atrovirens, lands and grass-heaths or among snow-bed vegeta- Polytrichum commune and Racomitrium fascicu- tion. It is a local but widespread community found lare. Rare bryophytes which have been recorded through much of Scotland, the Lake District in this community include Anthelia juratzkana, and Snowdonia. which almost totally replaces A. julacea in some Anthelia julacea – Sphagnum auriculatum stands, and Pohlia ludwigii. spring is an essentially stable community in the The commonest vascular plant is Deschampsia harsh environment in which it characteristically cespitosa. Scattered plants of Nardus stricta occur occurs. quite often with occasional Narthecium ossi- fragum, Pinguicula vulgaris, Carex demissa, and No sub-communities.

63 M32 Philonotis fontana – This is a community of springs and rills at moderate to high altitudes, above 450 m to over Saxifraga stellaris spring 1000 m, where there is irrigation with circum- neutral and oligotrophic waters with a pH of These bryophyte-dominated springs, flushes and around 4.5-6. This is one of the most common rills are striking in appearance. Philonotis fontana is and widespread types of spring vegetation in the usually dominant and obvious by its fresh-green uplands of north-west Britain and is dependent colour. The golden-green Dicranella palustris and on sustained and vigorous irrigation by ground- Scapania undulata are often also abundant. These waters, common in the wetter parts of the coun- species together often form cushions or plush mats. try. It marks out permanent springs of a well- Less consistent but sometimes prominent are defined character, also diffuse flushes and seep- Sphagnum auriculatum, Scapania uliginosa, Calli- age lines, rills and small streams and occasional- ergon sarmentosum, Drepanocladus exannulatus, D. ly steep, dripping ground. In some places snow- fluitans and the characteristic, but not very frequent, melt may be an important water source. It is Jungermannia exsertifolia. Bryum pseudotriquetrum found on a variety of waterlogged soils from frag- is also common, but not as consistent as in more mentary accumulation of silt among stones to base-rich springs, and Cratoneuron commutatum flushed peats and gleys. The community is and C. filicinum are scarce. common through the Scottish Highlands, the The associated vascular flora is rather varied in Southern Uplands, the Lake District and north composition and cover and typically species-poor. Wales and over the non-calcareous parts of the The only constant is Saxifraga stellaris, but Pennines. It can also be found as fragmentary Deschampsia cespitosa (with ssp. alpina at higher stands at lower altitudes without the montane altitudes) is often found in small quantities with element in the vegetation, particularly at the scattered Stellaria alsine. More occasional are southern limit of the range of this community. Festuca rubra, Anthoxanthum odoratum, Agrostis The harsh montane environment has a striking stolonifera and A. canina, all usually at low cover, influence on the composition of the community with sparse Viola palustris, Nardus stricta, Carex and though stands can be grazed and trampled, bigelowii and C. panicea. In stands which are climatic and soil conditions probably play the perhaps less base-poor, Montia fontana and major part in maintaining the vegetation as an Chrysosplenium oppositifolium become frequent effective climax. At lower altitudes, it could and abundant, along with Caltha palustris, perhaps show some successional development in Cardamine pratensis and a number of other ungrazed situations. associated species.

64 M32

Sphagnum auriculatum often abun- Sphagnum auriculatum and other dant, with Calliergon sarmentosum bryophytes listed opposite very scarce and Scapania uliginosa occasional and but Bryum pseudotriquetrum frequent. locally prominent. Montia fontana Montia fontana and Chrysosplenium and Chrysosplenium oppositifolium oppositifolium constant and sometimes very occasional. abundant.

M32a M32b Sphagnum auriculatum Montia fontana – Chrysosplenium sub-community oppositifolium sub-community In this species-poor sub-community Vascular plants are more numerous the bryophyte mat consists of mixtures and varied, although bryophytes still of Philonotis fontana, Scapania generally have dominance. Philonotis undulata and Dicranella palustris with fontana, Dicranella palustris and Sphagnum auriculatum strongly prefer- Scapania undulata are all very com- ential and often abundant. Calliergon mon and each, especially the first, can sarmentosum and Scapania uliginosa be abundant. Bryum pseudotriquetrum are occasional and Polytrichum com- is frequent and Jungermannia exsertifo- mune and Hygrohypnum ochraceum lia occasional. Among the vascular occur at low frequencies. Among the plants, Montia fontana and vascular plants only Saxifraga stellaris Chrysosplenium oppositifolium have and Deschampsia cespitosa are con- high frequencies with Saxifraga stel- stant but other grasses such as Agrostis laris, and are sometimes abundant. stolonifera, A. capillaris, Anthoxanthum Along with Stellaria alsine there are odoratum and Festuca rubra are quite often very small plants of Caltha palus- frequent as scattered tufts. tris (ssp. minor) and Cardamine praten- sis. Epilobium palustre can sometimes This sub-community occurs mainly on be found but more distinctive are the the harder acidic quartzites and sand- frequent occurrence of E. alsinifolium stones of the north-west Highlands. and E. anagallidifolium. Grasses can be quite common; Deschampsia cespitosa is often joined by Anthoxanthum odor- atum, Agrostis canina and several other grasses together with some sedges. This community is associated with a range of substrates slightly more base- rich than those of M32a.

65 M33 Pohlia wahlenbergii var. M34 Carex demissa – Koenigia glacialis spring islandica flush

In this community Pohlia wahlenbergii var. This is an open vegetation type with a glacialis dominates in spongy carpets of a bright bryophyte-dominated carpet broken by areas of apple-green colour, often of small extent, but wet, silty and stony ground. Scapania undulata, exceptionally up to 200 m2. Few other bryophytes Calliergon sarmentosum and Blindia acuta are occur with any frequency although P. ludwigii is a all common and each can be abundant, with occa- constant. Philonotis fontana can be prominent, sional patches of Dicranella palustris, Philonotis although not with the high cover found in fontana, Drepanocladus revolvens, Marsupella Philonotis fontana – Saxifraga stellaris spring aquatica and Sphagnum auriculatum. Scattered (M32). Other bryophytes recorded occasionally through this and over the rills are plants of Carex are Hygrohypnum luridum, Bryum weigelii, Calli- demissa, Koenigia islandica, Deschampsia cespi- ergon stramineum, Scapania undulata, S. uligi- tosa, Saxifraga stellaris, Juncus triglumis, J. bulbo- nosa, Dicranella palustris and Marchantia sus and the rare J. biglumis and Sagina saginoides. alpestris. All these are generally of low cover, though many In this carpet there are only a few vascular plants. can show a measure of abundance and Koenigia, Deschampsia cespitosa (presumably ssp. alpina) and although individual plants are small, can cover Saxifraga stellaris are constant, but Cerastium ceras- quite a large ground area. toides is quite often found and there can be Stellaria This community occurs on ground which is alsine, Chrysosplenium oppositifolium, Epilobium kept periodically moist by circumneutral and anagallidifolium, Veronica serpyllifolia var. humi- oligotrophic waters. Typically it is found in open fusa, and Rumex acetosa. Other rare plants found silty or stony flushes fed by vigorous seepage from occasionally are Epilobium alsinifolium, Alopecurus springs issuing at moderately high altitudes, alpinus and Phleum alpinum. over 500 m, from basalt. In their base status, This community is strictly confined to with pH values around 6.0, and their low cation spring-heads associated with late snow-beds content, the waters are similar to those which feed where there is vigorous irrigation by cold waters. the Philonotis fontana – Saxifraga stellaris spring The flushing waters, and often sloppy, ill-struc- community (M32), which often occupies the tured mixtures of mineral and organic matter spring-heads above the flushes. The community is beneath the moss carpet, are base-poor and confined to Skye, where it occurs scattered along oligotrophic. Although Pohlia wahlenbergii var. the Trotternish Ridge extending several kilometres glacialis occurs over quite a range of altitudes north of the Storr. It forms one of several through the uplands of Wales, Cumbria and communities in which Koenigia can be Scotland, it is only found with the kind of domi- found. nance characteristic here within the high montane zone at altitudes generally above 850 m. Within No sub-communities. this area, which includes the central and north- western Highlands of Scotland, the community is further restricted to situations where the snow lies longest, especially on north- and east-facing slopes. The general climatic and edaphic features determine the overall character of this community with its cold-tolerant plants and montane species.

No sub-communities.

66 M35 Ranunculus omiophyllus – M36 Lowland springs and Montia fontana rill streambanks of shaded situations

These rills typically have a rather crowded, though There is a clear contrast, among the Cardamino – not always continuous, cover of vascular plants and Montion springs and flushes of acid to circum- bryophytes. Much of the growth is often submerged neutral habitats, between the upland communities in the shallow waters, with a floating or shortly which have been described, where Montia emergent canopy. Ranunculus omiophyllus is often fontana, Saxifraga stellaris and Philonotis fontana abundant, frequently with Montia fontana. Floating are conspicuous, and the vegetation of lowland leaves of Potamogeton polygonifolius are common- and often shaded situations. In these, Chryso- ly prominent and there can be local patches of splenium oppositifolium occurs with bryophytes Agrostis stolonifera, Glyceria fluitans, Juncus bul- such as Hookeria lucens, Rhizomnium puncta- bosus, J. articulatus and Callitriche stagnalis, with tum, Trichocolea tomentella, Pellia epiphylla and scattered plants of Ranunculus flammula, a con- Conocephalum conicum. This type of vegetation stant, Myosotis secunda and Stellaria alsine. More has not been separately sampled here but it figures occasional are Ranunculus repens, Equisetum in the field and ground layers of various wet palustre, Hydrocotyle vulgaris, Galium palustre woodlands, notably the Alnus – Carex, Alnus – and Lotus uliginosus. Juncus bufonius and Scirpus Urtica and Alnus – Fraxinus – Lysimachia types, setaceus can sometimes be seen on open mud. where it is distinctive of seepage lines and damp Bryophytes can contribute substantially to the stream banks, quite often with Cardamine flexu- cover although there are only a few frequent osa, C. amara and Chrysosplenium alternifolium. species. Sphagnum auriculatum is a constant and Similar mixtures of plants can be found widely often grows semi-submerged with patches of through lowland Britain, especially in the wetter Philonotis fontana but, apart from occasional west and around the upland fringes, along Polytrichum commune, other species are sparse, stream-sides and wet banks, probably once with only occasional records of Calliergon wooded, but where shade is now provided by tall cuspidatum, C. stramineum, Drepanocladus exan- herbs or by the aspect of the site. These need nulatus, D. vernicosus, Scapania irrigua and further sampling. Rhytidiadelphus squarrosus. This community is typical of spring-heads and No sub-communities. rills at moderate altitudes in south-western Britain, where there is irrigation by circumneutral and probably quite oligotrophic waters. These are typically rather base- and nutrient-poor with pH values ranging from 4.5 to 6.5 over acidic rocks. It has been recorded only from south-western England, Wales, and around the Lake District. It may occur throughout the range of R. omiophyllus in Britain.

No sub-communities.

67 M37 Cratoneuron commutatum – Equisetum palustre, Chrysosplenium oppositifoli- um, Poa trivialis, Carex panicea, C. nigra and Festuca rubra spring C. dioica. This is a community of ground kept permanent- Cratoneuron commutatum occurs frequently in a ly moist by irrigation with base-rich, calcareous and variety of calcareous mires, but here it is generally oligotrophic waters. It is dependent on consistently dominant in large masses, often sustained irrigation common in areas of higher rain- forming prominent mounds or banks. In some fall. Here it can be found marking out spring-heads, stands of the same general floristic composition, seepage lines and drip zones in areas of lime-rich C. filicinum accompanies or totally replaces it. bedrocks, where waters emerge along bedding Other bryophytes can make a contribution, but planes or at junctions with impervious substrates. typically a minor one. However, the constant Provided the ground is permanently wet, the com- Bryum pseudotriquetrum is very common. munity can even occur on vertical surfaces and bare Occasional species include Philonotis fontana, P. rock, forming curtain-like masses. The community calcarea, Aneura pinguis, Pellia endiviifolia, can be found throughout the north-western uplands Drepanocladus revolvens, Gymnostomum recurvi- of Britain with its more Arctic-Alpine element best rostrum, G. aeruginosum, Brachythecium rivulare developed in the Scottish Highlands, with outliers and Dicranella palustris. Very typically there is in the Lake District and Upper Teesdale. Springs some tufa deposition allowing the mat to build dominated by Cratoneuron species also occur into mounds. The vascular element is typically widely, but locally, in the British lowlands, and fur- species-poor and of low total cover. There may be ther sampling of these is needed. considerable variation in associated flora and, par- In most circumstances it is a permanent ticularly where stands are developed on gently- community maintained by edaphic and climatic sloping ground, a richer and more extensive layer conditions of the environment. On gentle slopes, can be found, coming close to the Cratoneuron trampling by grazing stock or deer often plays an commutatum – Carex nigra spring (M38). Often, important part in maintaining the characteristically however the only species present are Festuca open conditions of flushed soils, but trampling rubra, Cardamine pratensis and Saxifraga and grazing can have an adverse effect on the aizoides, the last of which is absent from southern bryophyte carpet. Scotland and Wales. Occasional herbs include Agrostis stolonifera, Deschampsia cespitosa, No sub-communities.

68 M38 Cratoneuron commutatum – Juncus triglumis, J. articulatus, J. bulbosus, Cera-stium fontanum, Prunella vulgaris, Caltha Carex nigra spring palustris, Galium palustre, Equisetum palustre, Achillea ptarmica, Cochlearia officinalis (often This type of spring preserves the same pattern of ssp. alpina), Triglochin palustris, Ranunculus dominance by Cratoneuron commutatum (again acris, Anthoxanthum odoratum, Festuca ovina, occasionally supplemented or replaced by Epilobium anagallidifolium and, in north England, C. filicinum) as in Cratoneuron commutatum – the introduced E. nerteroides. In Teesdale this Festuca rubra spring (M37), but the associated community is the locus for Saxifraga hirculus. flora is much richer. This is partly seen among This vegetation is confined to montane springs the bryophytes. Bryum pseudotriquetrum and and flushes strongly irrigated by base-rich, Philonotis fontana are the commonest and can calcareous and oligotrophic waters. As in M37, have moderately high cover, and there are many sites of sustained irrigation with waters draining others which can occur locally as prominent from lime-rich bedrock are marked out and tufa patches. These include calcicolous species such as encrustation is often seen. It is very local around Aneura pinguis, Fissidens adianthoides, Philo- Upper Teesdale in the north Pennines and in the notis calcarea, Ctenidium molluscum, Cinclidium central Highlands of Scotland, mostly above stygium, Drepanocladus revolvens and Campy- 650 m altitude. lium stellatum. Although the harsh climatic and edaphic The increased richness is most seen among the conditions exert a strong influence on the vascular plants. Small sedges are noticeable. structure and composition of the vegetation, heavy Carex demissa, C. nigra and C. panicea are grazing plays a major role in maintaining the constant and often abundant, and C. pulicaris, distinctive richness of the community, and it is C. flacca and C. dioica are common. There are this trampling and cropping by sheep and deer frequent scattered plants of Cardamine pratensis, which is responsible for the most obvious floristic Selaginella selaginoides, Leontodon autumnalis, differences between this community and M37. Polygonum viviparum, Trifolium repens, Cirsium palustre, Ranunculus flammula, Sagina nodosa, No sub-communities.

69 4 Dendrogram keys to heath communities , , spp. . Erica , Galium saxatile See Fig 5. and the above , Hypnum Lowland and sub- Racomitrium lanugi- accinium myrtillus 5. nosum species not constant. At least one of: cinerea V Festuca ovina Deschampsia flexuosa and/or constant in the vegeta- tion. montane heaths , and , . C. uncialis , Cladonia See Fig 4. , Sub-montane and Sphagnum capillifolium 4. At least two of Racomitrium lanugi- nosum arbuscula 3a. if present, absent or, sparse and infrequent. Huperzia selago Empetrum nigrum hermaphroditum Cetraria islandica constant in the vegeta- tion. montane heaths spp. absent or, spp. absent or, See Fig 3. Ulex Sphagnum capillifolium if present, then not con- stant and subordinate in the vegetation. 2a. 3. constant within a luxuri- ant moss-carpet, usually over steep slopes with a thin mineral soil. See Fig 2. spp. constant in Calluna vulgaris Ulex 1a. constant and usually dominant in the vegetation. 2. the sward and usually prominent. See Fig 1. Calluna vulgaris 1. may be present but is not constant or prominent in the vegetation. A KEY TO HEATHS

70 Heaths Figure 1 Galium and Dicranum Deschampsia , , accinium myrtillus V Carex bigelowii Deschampsia flexuosa accinium myrtillus 3a. absent or infrequent, occasionally locally abundant. Vegetation usually dominated by V with constant saxatile flexuosa scoparium Pleurozium schreberi. H18 – heath , and heath Empetrum accinium myrtillus V Cladonia arbuscula Racomitrium ypical of the north-west Hylocomium splendens constant and abundant. Rhytidiadelphus loreus Racomitrium lanuginosum 4a. not constant but may be frequent. nigrum hermaphroditum and mats of bulky pleurocarpous mosses: Pleurozium schreberi T Scottish Highlands between the upper limit of ericoid dominance and summit moss-heaths H20 – lanuginosum absent. Montane (either sub- Empetrum generally subor- Empetrum . accinium myrtillus V Erica vagans Carex bigelowii Cladonia arbuscula Cladonia arbuscula accinium myrtillus ypical of the east and 3. constant and frequent. – heath H19 1a. V and/or nigrum species) constant and prominent. heaths in northern Britain 4. constant and abundant. Racomitrium lanugi- nosum dinate. nigrum hermaphroditum and bulky pleurocarpous mosses may be frequent but never abundant. T central Highlands between the upper limit of ericoid dominance and summit moss-heaths. , Ulex and co- – Ulex heath Carex flacca is not constant or prominent but may be present at low frequency. never prominent. Erica cinerea Erica vagans Erica vagans Polygala vulgaris. Erica tetralix 2a. dominant with Potentilla erecta europaeus. Ulex gallii and constant and frequent often with H6 europaeus Calluna vulgaris – present co- Schoenus Ulex These communities are almost entirely restricted to the Lizard Peninsula in Cornwall. ; Molinia Genista anglica Erica cinerea , , and E. tetralix Erica vagans Erica vagans Erica vagans Fig 1. Key to heaths in which 1. H5 and usually co-dominant with other species. Schoenus nigricans heath and 2. dominant with nigricans caerulea gallii sometimes frequent.

71 Heaths Figure 2

Fig 2. Key to heaths with constant Calluna vulgaris and in which Ulex spp. are constant and prominent

1. Ulex minor con- 1a. Ulex minor gener- stant and usually ally absent. Ulex gallii prominent. constant and promi- nent.

2. Agrostis curtisii, 2a. Agrostis curtisii 3. Agrostis curtisii, 3a. Agrostis curtisii Molinia caerulea, absent or present only Molinia caerulea, generally absent; Erica cinerea and E. at low frequency. Erica cinerea and E. Erica tetralix never tetralix Erica tetralix never tetralix frequent. constant. frequent. constant. Ulex europaeus may be abundant. H3 Ulex minor – H2 Calluna vulgaris – H4 Ulex gallii – Agrostis curtisii heath Ulex minor heath Agrostis curtisii heath H8 Calluna vulgaris – Ulex gallii heath

Restricted in its Found mainly in occurrence to Dorset and south-west Britain. Hampshire.

72 Heaths Figure 3

Fig 3. Key to heaths with constant Calluna vulgaris and Sphagnum capillifolium over a luxuriant bryophyte-rich carpet. Constants include: Vaccinium myrtillus, Empetrum nigrum nigrum, Deschampsia flexuosa, Rhytidiadelphus loreus, Pleurozium schreberi, Dicranum scoparium and Hylocomium splendens.

1. Vaccinium vitis- 1a. Vaccinium idaea and Cladonia vitis-idaea and arbuscula constant Cladonia arbuscula in the vegetation. absent or at very low Rubus chamaemorus frequency. Constant frequent and may be Potentilla erecta. The prominent. bryophyte carpet includes Dicranum majus and Plagiothecium undulatum. H22 Vaccinium myrtillus-Rubus chamaemorus heath H21 Calluna vulgaris – Vaccinium myr- tillus – Sphagnum capillifolium heath

Almost entirely Usually located on confined in its steep, north-east to distribution to the north-west facing central and north- slopes on thin miner- west Highlands. al soils, often with rock outcrops.

73 Heaths Figure 4 – also occasional C. uncialis can be Hypnum , Cladonia Deschampsia and Calluna vulgaris C. rangiferina. Racomitrium 3a lanuginosum frequent but is rarely abundant. spp. usually prominent including constant C. arbuscula H13 Cladonia arbuscula heath and Empetrum nigrum hermaphroditum constant. flexuosa cupressiforme and sparse. – heath, abundant . Erica cinerea sub-community Calluna vulgaris Cladonia arbuscula Racomitrium H10b Erica cinerea Racomitrium lanugi- nosum 4a. lanuginosum but not forming a dense mat. absent. constant. Racomitrium Cetraria islandica and – Erica Cladonia forms dominant, and/or Racomitrium constant, spp. may be frequent heath can be frequent. Calluna vulgaris Hypnum cupressi- Arctostaphylos alpi- absent or at very low Juniperus communis Racomitrium Racomitrium and at least two constants from: H14 Racomitrium lanugi- nosum 4. lanuginosum a dense woolly mat 5-10 cm thick. arbuscula cinerea but not constant. 3. lanuginosum usually with constant Cladonia uncialis. Empetrum nigrum (either sub-species), Deschampsia flexuosa and forme 1a. and nus frequency. lanuginosum Cladonia prominent. Empetrum nigrum hermaphroditum , Calluna vulgaris , – , usually absent. Huperzia selago Cladonia arbus- , , Calluna vulgaris Juniperus communis nana H17 Arctostaphylos alpinus heath 2a. ssp Arctostaphylos alpinus constant in a low open mat. Also constant: Huperzia selago Racomitrium lanugi- nosum cula and C. uncialis. Deschampsia flexuosa C. uncialis , , – , Erica , Cladonia arbuscula Cladonia , , or with constant heath Pleurozia Racomitrium , , Erica cinerea. Calluna vulgaris nana nana nana Juniperus communis Juniperus communis purpurea. cinerea lanuginosum uncialis 1. ssp. dominated 2. Vegetation by ssp. Arctostaphylos alpinus constant, usually with some Scirpus cespitosus Deschampsia flexuosa Potentilla erecta H15 Juniperus communis ssp. lanuginosum Fig 4. Key to sub-montane and montane heaths with constant

74 Heaths Figure 5 and , absent or Festuca heath – Calluna vul- Deschampsia H1 garis ovina 5a. flexuosa present only at low frequency. Calluna vulgaris usually the only abundant sub- shrub in a species-poor heath. Other con- stants include Festuca ovina Hypnum cupressiforme Dicranum scopar- ium. , or Pohlia , is constant may be locally heath Calluna vulgaris Calluna vulgaris vitis idaea Deschampsia flex-

accinium myrtillus Empetrum nigrum nigrum abundant. nutans but other pleurocarpous mosses are only occasional. 6a. always dominant but V H9 – uosa V. – accinium myrtillus V not , and/or Pleurozium accinium , Hypnum V usually , Dicranum Calluna vulgaris accinium myrtillus Erica cinerea Erica cinerea V Deschampsia flexuosa accinium myrtillus scoparium schreberi Hylocomium splendens. constant. Constant and frequent cupressiforme 5. constant. myrtillus 6. H12 frequent. V heath 4a. constant and present only at low frequency. constant in the vegetation. – constant heath and at least one of absent or rare. Calluna vulgaris Arctostaphylos Hypnum cupressiforme Erica cinerea 3a. uva-ursi and usually prominent. 4. H10 Erica cinerea and Calluna vulgaris , – , and and Erica Galium saxatile vitis-idaea

, V. , Calluna vulgaris and the following Carex arenaria Arctostaphylos uva- Arctostaphylos uva-ursi heath 3. ursi species constant: cinerea Deschampsia flexuosa Cladonia impexa H16 pleurocarpous mosses. 2a. Ammophila arenaria absent. – and heath Deschampsia flexuosa , Ammophila frequent but Calluna vulgaris Scilla verna Carex arenaria Plantago maritima absent. 1a. 2. constant but not often prominent. arenaria sparse. Sandy dunes and coastal plains. H11 Carex arenaria Festuca ovina , – and heath Calluna vulgaris Scilla verna Empetrum nigrum Fig 5. Key to lowland and sub-montane heaths with constant, usually dominant Plantago maritima constant in short heaths around maritime cliffs. Scilla verna 1. H7

75 5 Heath community descriptions and sub-community keys

H1 Calluna vulgaris – Festuca both pioneer and degenerate Calluna. In such sit- uations Hylocomium splendens, Pleurozium ovina heath schreberi, Ptilidium ciliare and Dicranella heteromalla are occasional. Lichens may exceed This is a heather-dominated community which is mosses in cover. Cladonia species are prominent very poor in vascular associates, although some- with encrusting species such as Cladonia pyxida- times showing a modest diversity among the ta, C. squamosa and C. fimbriata on bare ground. bryophytes and, more especially, the lichens. Species like C. impexa, C. furcata and C. arbuscu- Calluna vulgaris is usually the only woody species la are especially abundant on old Calluna togeth- and the most abundant. The height and cover of er with Hypogymnia physodes. the canopy are very variable depending on the age This community is confined to acid, base-poor of the heather and the consequent phase of and oligotrophic sandy soils in the more development, and also on grazing intensity. Erica continental lowlands of eastern England. The cinerea, Ulex minor and U. gallii, important in dry profiles under the community are usually brown heaths further south and west, are largely exclud- sands which are free to excessive-draining and ed as is Erica tetralix. Ulex europaeus is uncom- have a low surface pH. In some localities, such as mon, except where there has been disturbance. in Lincolnshire and around the Weald, the Typically there are no grassy areas but Festuca impoverished soils are derived from arenaceous ovina is very common throughout, usually as bedrock, but they have mostly developed from scattered tussocks, often with less than 30% total sandy glacio-fluvial drift, sometimes supplement- cover. Other grasses are few. Agrostis capillaris is ed by aeolian sand. The community occurs occasional and there may be a little Deschampsia through the eastern lowlands of England, although flexuosa. Associated dicotyledons are also few it is now very local. and patchy. Occasionally Senecio jacobaea, This heath has been traditionally managed Galium saxatile, Cerastium fontanum, Camp- with burning and grazing (both domestic livestock anula rotundifolia and Luzula campestris may be and wild herbivores such as rabbits and deer). present. Two species locally important in particu- However in many areas the abandonment of this lar situations are Pteridium aquilinum and Carex traditional management has been followed by arenaria. In bare areas Rumex acetosella together agricultural improvement or afforestation which with ephemerals such as Aphanes arvensis, has reduced and fragmented tracts of this Teesdalia nudicaulis, Myosotis ramosissima and community. In other areas the lack of grazing and the annual Aira praecox may be found. burning has often permitted seral progression to Only a few bryophyte species occur throughout scrub and woodland. The most common woody the community. Hypnum cupressiforme and invaders are Betula pendula and Pinus spp., and Dicranum scoparium are both constant. These two more occasionally, Quercus robur if mature trees usually form the bulk of the bryophyte cover in are fairly close by.

76 H1e Calluna vulgaris. Hypnum cupressiforme. ry impoverished rank Ve canopies of Species-poor sub-community Unbroken canopies of dense up and often tall heather, to 50 cm or more high, are characteristic here, among which virtually no associates can survive, apart from occasional sparse plants of This sub-community is typically of building and mature heather. Festuca but other , Hypnum constant, , sometimes is frequent. H1d occurs sparsely Lichens poorly represented. Carex arenaria sometimes abundant. cupressiforme This sub-community is found on coastal and inland dune systems. herbs are scarce. Among the cryptogams only Carex arenaria sub-community The heather is often tall and somewhat open with scattered plants or denser patches of Carex arenaria co-dominant and growing on sandy soil profiles. ovina sometimes with a little Rumex acetosella and and Agrostis Rumex , remain frequent . Lichens eucrium Deschampsia T , Senecio jacobaea H1c Galium saxatile Festuca ovina, or Galium saxatile , and and scattered H1 Senecio jacobaea ithin more open areas eucrium scorodonia eucrium scorodonia T sub-community Degenerate bushes are scarce and heather cover is generally vigorous and extensive. W scattered plants of scorodonia can be found or small stretches of turf with Agrostis capillaris flexuosa acetosella Cerastium fontanum are very infrequent, but Hypnum cupressiforme Dicranum scoparium common. capillaris occasional. with T – is most , Dicranum Hypnum and , C. macilenta. and H1b , common. , is more uneven, and Cladonia impexa locally rather C. impexa Festuca ovina , Bryophytes rather patchy but lichens often extensive with Cladonia furcata C. macilenta Hypogymnia physodes Cladonia impexa sub-community The heather cover is the same as in H1a but degenerate bushes predominate. The contribution of cupressiforme scoparium the mosses occurring as small patches among collapsed stems. Lichens by contrast are abun- dant in these areas, encrusting species being joined or exceed- ed by C. furcata Hypogymnia physodes frequent here. Cladonia uncialis , , Cornicularia aculeata C. pyxidata , , and Calluna vulgaris very and are very C. impexa Hypogymnia physodes and in C. arbuscula Cover of open with some of C. fimbriata abundant on mor and bare ground. C. squamosa and and the cryp- H1a C. fimbriata , and Cladonia pyxidata usually predominate, Calluna vulgaris C. uncialis being less frequent and Hypogymnia physodes occasional. Hypnum cupressiforme common among collapsed Calluna vulgaris grassy patches. C. squamosa C. gracilis bulkier species like Dicranum scoparium frequent. Lichens are also abundant, Hypnum cupressiforme sub-community Cover of is often less than complete and only moderately tall. The most prominent associates are Festuca ovina togams which often exceed Among the mosses 50% cover. Hypnum cupressiforme

77 H2 Calluna vulgaris – saxatile may also be found in more open areas. In some stands invading seedling and sapling trees Ulex minor heath may occur, particularly Quercus spp., Betula spp. and Pinus sylvestris. This community is generally dominated by In the absence of burning, mosses and lichens Calluna vulgaris, but with both Erica cinerea and can become common. Dicranum scoparium and Ulex minor playing a very frequent and sometimes Hypnum jutlandicum are the most frequent prominent role in the sub-shrub layer. The bryophytes, with peat-encrusting Cladonia species constancy of the latter two species provides the and larger species such as Cladonia furcata and most obvious floristic distinction between this C. arbuscula. Hypogymnia physodes can some- community and the Calluna vulgaris – Festuca times be found on old heather stems. ovina heath (H1). The canopy is very variable in This community is characteristic of impoverished height, from 10 cm to 80 cm or more, and the acid soils, predominantly free-draining in south-east structure depends greatly on the growth phase of and central southern England. It is characteristic of the Calluna and whether the individuals are of free-draining profiles developed from pervious arena- even or uneven age. Where burning occurs (for ceous or pebbly parent materials. Typically, these par- example, in the New Forest) a characteristic ent materials have given rise to some kind of podzolic patchwork of swales is formed. After fire E. cin- profile under this community which is highly acidic, erea often increases in frequency because of its often with a superficial pH between 3.5 and 4.5, and prolific seeding. Ulex minor normally plays a sub- generally impoverished. The community occurs from sidiary role, forming a patchy understorey below the Poole Harbour area in the west through the New the Calluna. No other sub-shrubs are found Forest, where stands are particularly numerous and throughout the community. Ulex europaeus is extensive, to Surrey and the High Weald in the east, occasional, but may be locally abundant after where it occurs as more local and fragmented tracts of disturbance. Erica tetralix and Vaccinium myr- heathland. tillus are found in particular sub-communities. The vegetation takes much of its structural, and Other consistent associates are very few. some of its floristic, character from traditional Deschampsia flexuosa is constant but patchy, grazing and burning treatments. However, when though it may be more common in grazed areas. released from these treatments a progression to On wetter soils it tends to be replaced by Molinia woodland can be expected. Agricultural improve- caerulea. Pteridium aquilinum is occasional ments and forestry have caused fragmentation and overall and preferential for one sub-community. isolation of small remnants of this community in Scattered plants of Potentilla erecta or Galium many places.

78 , occur is com- is scarce. and tree spp. patchi- Ulex minor all slightly , the latter accinium myr- occasional at is generally V Dicranum sco- H2a C. chlorophaea Hypnum ericeto- Festuca rubra. , Deschampsia flexuosa Cladonia Erica tetralix and nor Cladonia fimbriata with Erica cinerea C. arbuscula Molinia caerulea ypical sub-community Molinia caerulea most with very common. parium rum ly prominent in more open areas. T Calluna vulgaris strongly dominant with sub- sidiary amounts of and very variable and sometimes absent. Neither and preferential. tillus and Deschampsia flexuosa mon and sometimes with or replaced by Pteridium aquilinum seedlings are infrequent. Bryophytes and lichens can be conspicuous among older heather or after burning, with C. coccifera can be accinium V and young trees very Pteridium aquilinum quite common, but myrtillus scarce. is uncom- very common, is abundant, which may be Molinia caerulea. and particularly H2c More obviously E. cinerea. frequent and sometimes Ulex minor Erica cinerea Molinia caerulea often almost totally displacing Deschampsia flexuosa. Erica tetralix exceeding Molinia caerulea sub-community Calluna vulgaris usually with smaller amounts of of joined with or replaced by Erica tetralix. preferential is Pteridium aquilinum mon and young trees are rarely found. The ground layer is also sparse. This sub community is predominantly found on soils with impeded drainage. H2 Erica , and Pteridium and are occa- is more constant Molinia H2b Ulex minor oung trees are also frequent and with Y and, strongly preferen- accinium myrtillus. V accinium myrtillus accinium myrtillus V sub-community The sub-shrub canopy usually consists of mixtures heather with sometimes substantial amounts of cinerea tial, sional but lichens are sparse. This sub-community tends to be found at the higher altitudes in the range of H2. occasionally a little Dicranum scoparium Pteridium aquilinum frequent, and in open areas there is usually some Deschampsia flexuosa caerulea. strongly preferential, with oak and birch seedlings saplings frequent, and small pines locally prominent. Hypnum jutlandicum V and locally abundant, aquilinum scattered tree seedlings and saplings.

79 H3 Ulex minor – Agrostis curtisii heath bryophytes Campylopus brevipilus is most distinc- This community contains nearly all the sub-shrub tive and can be accompanied by C. paradoxus, vegetation in which Ulex minor and Agrostis Polytrichum juniperinum, Dicranum scoparium, curtisii occur together as important components, Hypnum jutlandicum and Leucobryum glaucum. although A. curtisii can also occur occasionally in Cladonia impexa is one of the most common and Calluna vulgaris – Ulex minor heath (H2). The conspicuous lichens with peat-encrusting species canopy is usually fairly low, 20-30 cm high, and such as C. floerkeana, C. coccifera and C. pyxidata. Calluna frequently dominates, especially when it Hypogymnia physodes often colonises old heather has not been burned for some time. Compared with stems. less oceanic heaths the most unusual feature of the This community is the characteristic sub-shrub woody cover is the occurrence together of Erica community of impoverished acid soils which are cinerea and E. tetralix, both of which are constants. protected against parching by a measure of Both can grow vigorously, although E. cinerea is drainage impedance and a moderately oceanic likely to be more prominent especially after burn- climate. It occupies a distinct position on soils ing. Erica tetralix can have high cover locally, espe- that are too dry for the Erica tetralix – Sphagnum cially on more strongly gleyed soils. Ulex minor compactum wet heath (M16) and too moist for the maintains its high frequency throughout, although Calluna vulgaris – Ulex minor heath (H2). It is its abundance is very variable. In stands which largely confined to south Dorset and Hampshire. have not been burnt for some time A. curtisii and The combination of drainage impedance and Molinia caerulea, the two characteristic and con- climate is the major influence on the floristics stant grasses, are generally scattered, but after of this community, although grazing and burn- burning A. curtisii and to a lesser degree Molinia ing still often exert an important measure of can become prominent. In contrast to H2 control on its composition and structure. The Deschampsia flexuosa is very scarce. Pteridium general effect of the combination of these treat- aquilinum occurs occasionally and other herbs are ments is to curtail the mature and degenerate found as scattered individuals. Potentilla erecta, phase of Calluna and to set back repeatedly any Polygala serpyllifolia, Carex pilulifera and the par- invasion of trees and seral progression to wood- asitic Cuscuta epithymum can all be found occa- land. The abandonment of traditional land use sionally. In disturbed or burned situations Viola and soil improvement for agriculture in many lactea is very characteristic. stands of this type of vegetation has meant that Burning has the effect of opening the canopy, and surviving tracts can be fragmented, and are mosses and lichens become prominent. Among the often sharply delineated from their surrounds.

80 is Carex , Erica ciliaris as the main Ulex europaeus H3a Polygala serpyllifolia Potentilla erecta , Cuscuta epithymum. ypical sub-community pilulifera or Bryophytes and lichens are sparse. preferential at low frequency, and there is sometimes a little Pteridium aquilinum T The sub-shrubs typically form often with an extensive canopy, Calluna vulgaris dominant, although, sometimes more mixed. Grasses are usual- ly subordinate. is occasional and is found in south Dorset vegeta- tion. Other species are few, although Species opposite very sparse among usually dense sub-shrub canopies. Ulex Calluna vul- very frequent, occasional at most dominated canopies. garis- but not extensive, and europaeus among mixed or Agrostis curtisii , , a , common C. floerk- , is the leading H3b spp. sub-community C. coccifera. Campylopus brevipilus and Polygala serpyllifolia Cladonia The sub-shrub canopy is somewhat open, and although Calluna vulgaris species, dominance is often shared between woody plants and strong preferential here. There is a noticeable cover of mosses and lichens, the species listed above being most frequent. Polygala serpyllifolia with a patchy cover of bryo- phytes and lichens on more open areas. Species present include Polytrichum juniperinum Cladonia impexa eana H3 and often Erica very often co- Ulex and Erica are patchy and sub-community is very abun- somewhat Ulex europaeus iola lactea hich then per- Molinia caerulea Ulex minor H3c V ,w is strongly preferen- Erica cinerea Agrostis curtisii much reduced in reduced in frequency Calluna vulgaris Ulex minor iola lactea Agrostis curtisii Agrostis curtisii dant and Molinia caerulea tial in this sub-community where disturbance, often by burning, is characteristic. The early stages of development often allow colonisation by V sists as the dominants expand. dominant, but and tetralix europaeus frequency and cover. frequency and cover. Calluna vulgaris tetralix and cover and patchy. persistent. common and abundant with

81 H4 Ulex gallii – Agrostis heaths, Festuca ovina and Danthonia decumbens are particularly important, with the sedges Carex curtisii heath binervis and C. pilulifera also characteristic. On cooler, moister slopes Scirpus cespitosus can be This community is very similar to Ulex minor – prominent. The only dicotyledonous herb which Agrostis curtisii heath (H3), with the replacement is a constant of this community is Potentilla erec- of one gorse by another. The western limit of ta, which occurs as scattered individuals. Other U. minor in east Dorset forms the boundary bet- occasional herbs are Polygala serpyllifolia and ween these two heath types. Apart from this dif- Pedicularis sylvatica, with Viola lactea in dis- ference they share five constants, namely, Calluna turbed situations. There are a variety of bryo- vulgaris, Erica cinerea, E. tetralix, Molinia caer- phytes and lichens, but none occur with any ulea and Agrostis curtisii, and these species, frequency. together with U. gallii, generally account for the This community is confined to the warm bulk of the vascular cover. Their proportions and oceanic parts of south-west Britain where it occurs structure, however, vary considerably so that the on a variety of moist, acid soils. Like its eastern appearance of stands differs markedly. The vegeta- counterpart, H3, this is a vegetation type of acid tion can vary from a short mixed canopy of grass- soils that are too moist for dry heath but not so es and sub-shrubs no more than 10 cm high (grass consistently waterlogged as to be able to sustain heath), to a canopy of woody plants 50 cm or more wet heath. The community is confined to south- high. There may also be quite extensive areas of west Britain, beyond a line from mid-Dorset to the barer ground. Calluna and U. gallii are the most Quantocks, and including parts of the south Wales common species and are often abundant. Calluna seaboard up to altitudes of 500 m. often dominates. The frequent occurrence of Both climatic and edaphic conditions combine E. cinerea and E. tetralix together distinguishes to influence the general character of this vegetation. this vegetation from the corresponding dry heath However, in most situations burning and grazing Calluna vulgaris – Ulex gallii heath (H8). Four have a marked effect on the floristics and physiog- other sub-shrubs are more restricted. Vaccinium nomy of the vegetation and, with the exception of myrtillus is commoner at higher altitudes with situations such as the Lizard where exposure to increased rainfall. The others, Salix repens, Erica high and frequent winds is combined with a scarci- ciliaris and E. vagans (a species restricted to ty of seed parents, these treatments are important the Lizard in Cornwall) are found in the wetter for maintaining the community against succession E. tetralix sub-community. to woodland. As with many lowland heath com- Two grasses are constant, Agrostis curtisii and munities intensive improvement for agriculture Molinia caerulea, which always make some and afforestation has reduced and fragmented its contribution to the cover. Among the grassier extent.

82 or , , and absent from Erica vagans is frequent occasional. This sub-community H4c Erica ciliaris locally abundant. Erica tetralix occur in this type of Danthonia decumbens E. ciliaris Scirpus cespitosus vegetation variously dominated by one or more sub-shrubs and grasses and with or and each can be abundant. Potentilla erecta and E. vagans heath. Bryophytes and lichens show a varying representation. This sub-community is espe- cially characteristic of lower altitudes and is well represent- ed on the Devon Pebble-Bed commons, the lower fringes of Dartmoor and Bodmin Moor and on the Lizard. Polygala serpyllifolia Carex panicea vegetation is best known on the Lizard where Erica tetralix Both grasses and sub-shrubs have very high frequency, including E. tetralix and , both Ulex , . are fre- Erica and E. cinerea , but with constant in is constant Erica cinerea both very common, but associ- ates listed opposite occasional at most in a less grassy heath. and sub-communi- occasional. H4d Calluna vulgaris Cladonia impexa Agrostis curtisii Festuca and common accinium myrtillus and C. uncialis V Calluna vulgaris a frequent Scirpus cespitosus vegetation usually dominated by other sub-shrubs and grasses locally abundant. ty, can be found at higher alti- ty, tudes on Dartmoor and Exmoor. gallii constants, distinguish this sub- community from wet heath. Dicranum scoparium Leucobryum glaucum quent and and along This sub-community, with the tetralix and Scirpus cespitosus sub-community Scirpus cespitosus and strongly preferential with very frequent Molinia caerulea component of the sub-shrub community. Erica tetralix , Calluna Erica and accinium myr- Erica tetralix- Bryophytes and V common in Carex Festuca Galium sax- is very common, , H4b C. binervis. H4 rather patchy but Ulex gallii is often the most abundant and sub-community Galium saxatile. and occasional have high frequencies; sub-community, can be found at sub-community, is more patchy and accinium myrtillus Potentilla erecta is most common in this sub-commu- Erica cinerea V a grassy heath with ovina, Danthonia decumbens Agrostis capillaris atile pilulifera Festuca ovina Agrostis curtisii species, most commonly with a fairly rich mixture of sub-shrubs and herbs forming a grass heath. Both vulgaris cinerea often with common but not constant. tillus often as sparse shoots. The associates nity, listed above are more abundant and prefer- ential. lichens are very sparse in ungrazed stands but occasional in grazed vegetation. along with the This sub-community, Scirpus higher altitudes on Dartmoor and Exmoor and also throughout the range on free-draining soils with grazing. Agrostis cur- Otherwise all which is often dom- Erica cinerea H4a – very infrequent in vegeta- Erica tetralix. E. cinerea. or Agrostis curtisii Agrostis curtisii sub-community Unusually there is an almost total absence of inant, forming a virtually pure and tus- socky sward. Other grasses do not gen- Other vascular erally increase in cover. and cryptogam associates are few in number. This sub-community occurs throughout the range of H4 and is often present as regenerating vegetation after burning. the constants remain frequent except for tion usually dominated by Erica tetralix tisii

83 H5 Erica vagans – Schoenus There are a number of occasional associates. On wetter ground Phragmites australis can be present nigricans heath as conspicuous but scattered shoots. Bryophytes vary considerably among stands This heath is one of two sub-shrub communities but Campylium stellatum is constant and in which the nationally-rare Erica vagans makes very frequent in runnels and may be abundant, a constant and prominent contribution. Schoe- often with Riccardia multifida, R. sinuata and, nus nigricans is also constant and usually abun- over gabbro, Scorpidium scorpioides. After wet dant as strongly-developed tussocks. Molinia weather runnels often have swollen gelatinous caerulea and Erica tetralix are also constant, globules of blue-green algae. often with high cover, and together these four This community is confined to wet, base-rich species dominate in mixtures. Between these but calcium-poor mineral soils and shallow species there is a well-defined system of runnels peats on the Lizard in Cornwall. Here the distinc- giving a distinct microhabitat. Among other sub- tive parent materials of serpentine and gabbro shrubs only Ulex gallii occurs with any frequen- found in this area have given rise to soils that have cy and may be co-dominant. Calluna is only a superficial pH of between 5.5 and 7.5 but in occasional and E. cinerea scarce. Genista anglica, which magnesium predominates over calcium. however, can occur frequently and is preferential The community makes the major proportion of the to this community. open and enclosed heaths of the hinterland of In undisturbed stands which have not been the peninsula. burnt or grazed recently, Schoenus and E. vagans The floristics of this community are influenced tend to be dominant and the vegetation is choked both by the mild oceanic climate and underlying with their litter. Then, even common associates bedrocks of serpentine and gabbro, but the com- like Potentilla erecta and Festuca ovina can be position and physiognomy of particular stands are crowded out. After burning or grazing, or both, the affected by burning and sometimes also by graz- associated flora is much richer. In the wetter run- ing. Other past treatments like the cutting of turf nels sedges are often important with Carex puli- have also probably influenced the appearance and caris constant, C. panicea and C. flacca frequent distribution of this community. There have and, on gabbro, C. hostiana. Anagallis tenella, also been losses of this vegetation type to modern constant, may form extensive mats. Among taller techniques of land improvement and much of the herbs Serratula tinctoria and Succisa pratensis are remaining extent has statutory or voluntary pro- constant and Sanguisorba officinalis frequent. tection.

84 H5

Frequent Eleocharis multicaulis, Vegetation variable in composition Eriophorum angustifolium, Drosera and structure, but species listed rotundifolia, Pinguicula lusitanica, and opposite rare. Dactylorhiza incarnata incarnata grow- ing in runnels that are usually flooded for much of the year. In ungrazed stands, Phragmites australis may be locally abundant.

H5b H5a

Eleocharis multicaulis sub-community Typical sub-community

Schoenus nigricans dominant with This vegetation has all the general Molinia caerulea and Erica vagans. features of the community with no Erica tetralix is somewhat less abun- additional preferential species. The dant. Calluna vulgaris and Erica tussock/runnel structure is often well- tetralix usually absent and Carex defined, but species-richness depends panicea is also typically missing. greatly on treatment and especially time since burning.

85 H6 Erica vagans – Ulex Thymus praecox, Lotus corniculatus, Galium verum, Jasione montana, Danthonia decumbens europaeus heath and Brachypodium sylvaticum. Immediately after burning, diversity is increased, with ephemerals This community is a distinctive type of sub-shrub including Aira caryophyllea and Centaurium vegetation, but rather variable in floristics and erythraea. Continued burning and the dense shade structure. The most obvious feature is a mixed and litter of older stands inhibit bryophytes and canopy of sub-shrubs in which Erica vagans and lichens, which as a result are uncommon. Ulex europaeus are the usual co-dominants. The This community is confined to the Lizard in canopy is generally 30-60 cm high but in exposed Cornwall where it is characteristic of free-draining situations may be not more than 10 cm high. brown earths that are usually quite base-rich but Two other constant sub-shrubs, Ulex gallii and calcium-poor and fairly oligotrophic. It is found E. cinerea, can also be abundant although the for- on soils similar to that of H5 with a pH of general- mer may be suppressed in dense stands. Calluna ly between 5 and 7, but which are more free-drain- vulgaris is not frequent and has generally ing. Therefore it is typically found on the steeper, low cover. shedding slopes around coves and on the cliff tops In contrast to the Erica vagans – Schoenus of the headlands. Although it is mainly coastal in nigricans heath (H5) community, E. tetralix is only distribution it is not strictly speaking a maritime occasional and confined to wetter soils (see heath and is replaced on slopes which are sub-community H6d) with several preferential exposed to salt spray by Calluna vulgaris – associates. The only herbaceous associates Scilla verna heath (H7). common throughout are Carex flacca, Potentilla Edaphic variation and local differences in the erecta and Polygala vulgaris. The most common warm oceanic climate strongly influence floristic and distinctive herbs of this community are Viola diversity, but treatments, especially burning, and riviniana, Filipendula vulgaris, Stachys betonica, to a lesser extent grazing, also have a marked effect Hypochoeris radicata, Agrostis canina ssp. on composition and physiognomy of the vegeta- montana, Dactylis glomerata and Scilla verna. tion. However, the progression to scrub and wood- Most of these species are found in recently burned land in the absence of these treatments would stands but become more scattered and reduced in probably be slow due to the lack of seed parents number as the vegetation and litter increase. and the poor quality of the soil. Preferential culti- On shallower soils, especially when grazed, a vation of the more fertile soils developed over gab- rich short herb layer is maintained with several bro and schists means that the community sur- additional species including Festuca ovina, vives most extensively over serpentine.

86 Prunus eucrium T eucrium agg., T Geranium san- Geranium san- H6a Pteridium aquil- and and but associates listed , , the only preferential and only Potentilla and scattered , pical sub-community ypical heath with a complete inum scorodonia guineum opposite very sparse in more recently regenerating stands. Sub-shrub canopy usually extensive with occasional Rubus fruticosus spinosa Ty T range of floristic and structural vegetation related to burning. A few years into the cycle there is a well-developed sub-shrub canopy with most of the com- munity constants. Richer stands have occasional scorodonia guineum dicotyledons here. With increasing age the constant herbs begin to thin out leaving a dense woody cover. very frequent but absent and , Serratula tinctoria Koeleria , spp. and Hypnum Leontodon is frequent Potentilla sub-community and occasional. Filipendula vulgaris Molinia caerulea erecta H6b as constants. Cladonia Aira caryophyllea , the common herbs are all cupressiforme s.l. erecta well represented in this sub- In the more open community. conditions there are more cryp- togams than usual, and various Sub-shrub canopy usually low and open with a rich flora between the bushes including Danthonia decumbens macrantha Galium verum taraxacoides Festuca ovina Here the abundance and height of the sub-shrub canopy is less than in the typical form with a total cover of often less than 50%. Apart from common. H6 Erica Both and iola rivini- V Calluna vul- Ulex occur with , is constant in Molinia and associates Schoenus H6d and Sanguisorba and Ulex gallii. retain high frequen- fre- and frequent. rather is distinctive. Its litter constant in small are reduced in frequency Carex flacca Potentilla erecta Erica tetralix , Agrostis curtisii listed opposite absent, but tetralix amounts and officinalis nigricans Molinia caerulea sub-community Erica vagans europaeus cy and abundance with smaller amounts of Erica cinerea garis but small amounts. In stands not recently burned caerulea depresses herbs and generally only ana Stachys betonica with small any frequency, amounts of the preferentials listed above. Potentilla erecta and Serratula tinctoria and , is Filipendula vulgaris scarce. iola and V is absent , Calluna vul- Ulex gallii Erica are common, Among the , are very fre- constant and Agrostis curtisii Molinia caerulea constant with quent, but uncommon. H6c Carex panicea Polygala serpyllifolia Stachys betonica Molinia caerulea E. cinerea iola riviniana , and V scarce. U. europaeus. Filipendula vulgaris Agrostis curtisii often abundant, particularly after burning, with garis Hypericum pulchrum lactea frequent. Agrostis curtisii sub-community Apart from occasional occur- rences in H6a, is largely confined to this sub- community where it can be very abundant especially after burning. also frequent and the two grass- es sometimes dominate under an open canopy of vagans and herbs and Danthonia decumbens Potentilla erecta quent and Serratula tinctoria as are the preferential species listed above.

87 H7 Calluna vulgaris – corniculatus, Thymus praecox and Hypochoeris Scilla verna heath radicata, the latter of which tends to favour drier soils. Anthyllis vulneraria also favours drier soils In this heath, sub-shrubs are a consistent feature, as do Euphrasia species. Other species are more though they are not always obvious. The canopy is characteristic of particular sub-communities. typically very short, rarely over 20 cm, and some- In contrast cryptogams are few and never times when grazed forming a mat only 2-3 cm show high cover. Among the mosses only Hypnum high. The cover of woody plants is rarely continu- cupressiforme s.l. is moderately frequent and ous. Even where sub-shrubs are more extensive, Frullania tamarisci, the commonest hepatic, is they are commonly penetrated by herbs. Calluna infrequent. Several Cladonia species are occasional. vulgaris is the most frequent sub-shrub and the This community occurs over a wide variety of commonest dominant, though on dry soils it is moderately base-poor soils on the less exposed accompanied by Erica cinerea. On wetter soils the parts of maritime cliffs all around the coast of latter is much reduced and E. tetralix and/or Britain except to the east and south between Empetrum nigrum ssp. nigrum are the usual asso- Durham and Dorset. The single most distinctive ciates. No other woody species occurs frequently difference between the habitat of this kind of throughout, although Ulex gallii is occasional. heath and the habitats of other sub-shrub commu- Among herbaceous associates grasses are often nities is the input of salt spray generated by break- important. Festuca ovina is the most frequent ing waves and carried inland by the wind. grass species, though F. rubra is also common. The floristic and structural variation in this Also common and a constant is Holcus lanatus, community is influenced by the climatic and often with Dactylis glomerata on drier soils or edaphic differences both throughout the consider- Danthonia decumbens on moister ground. In able geographic range of the community and over wetter, northern heaths Agrostis capillaris and particular stretches of cliff. Grazing also affects the Anthoxanthum odoratum can become very composition and appearance of the vegetation and common, but Molinia caerulea is infrequent. probably contributes to maintaining it against suc- There are a variety of other herbs. Most distinctive cessional change. However, over much of its range among the constants are Plantago maritima and this vegetation can be considered a climatic cli- Scilla verna. Other common and constant species max as exposure to even small amounts of salt are Plantago lanceolata, Potentilla erecta, Lotus spray hinders the invasion of woody invaders.

88 and is and hough is quite ,alt Erica cinerea dominated is the usual occasional Armeria H7e less common. Festuca ovina bra Thymus praecox sub-communities though F. ru occasional iola riviniana iola and V but other listed associates rare among an often impoverished Calluna vulgaris- cover. usually with a taller canopy. Calluna vulgaris dominant though is common; all other sub-shrubs are scarce. the most frequent grass with Calluna vulgaris sub-community In general floristics this heath type resembles impoverished versions of the V Hypochoeris radicata frequent but rosette herbs are poorly represented in the rank herbage. Lotus corniculatus common are often not abundant. This sub-community is found throughout the range of H7 but is rarer to the north, although it is well-represented in Shetland. , and Erica C. nigra and remain very Serratula Leontodon Erica Erica cinerea , Empetrum and are typically Anthoxanthum , sub-communi- Dactylis glomerata Anthyllis vulneraria but other listed associates rare. and and sub-community frequent. Polygala , and H7b Erica tetralix Galium verum , Ulex europaeus Carex flacca occasional and Armeria E. tetralix very frequent and often , and occasional but Carex panicea , iola riviniana iola riviniana taraxacoides Achillea millefolium Stachys betonica C. caryophyllea tinctoria vagans locally prominent. vulgaris V V occurs throughout the range ty, of H7 but is better developed south of Galloway with only local stations north of this. The sub-shrub canopy is more extensive than in H7a with both Calluna vulgaris Empetrum nigrum very scarce. The herbaceous plants are most distinctive. All the community constants are well represented together with the species listed above. along This sub-community, with the cinerea co-dominant. Hypochoeris radicata are rare. nigrum Agrostis capillaris odoratum and frequent and as , and Holcus Dactylis Sedum and occa- Erica vulneraria , and and sub-community, H7a Festuca ovina Dactylis glomerata. Potentilla erecta Anthyllis iola constant and often , requently with V and ,f , although the latter is Plantago coronopus H7 Jasione montana rubra

sional which is scarce, all other com- munity constants and the asso- ciates listed above are well rep- resented. along This sub-community, with the occurs throughout the range of H7 but is better developed to the south of Galloway with only local stations beyond this. and Silene vulgaris maritima. Armeria maritima sub-community Here, where salt-spray deposi- tion is high, the canopy of sub- shrubs is generally less exten- sive, either with a mosaic of open areas or reduced to dis- crete patches of bushes. The only common sub-shrubs are Calluna vulgaris cinerea reduced in exposed situations. Growing among and between the bushes is the dominant, sometimes with F. lanatus Apart from Armeria maritima anglicum abundant with frequent glomerata , Erica are rubra lance-

nigrum F. P. , is very Lotus Luzula ssp. Danthonia and constant, and and often , Ulex species and Empetrum and and Succisa praten- H7d and Carex panicea common, while and reduced in quite common. Calluna vulgaris. Festuca ovina is seldom found but which is often co-domi- lanceolata

are very frequent and Erica tetralix P. Empetrum nigrum Carex panicea only very occasional but rifolium repens and Anthoxanthum odoratum frequent and common. Among dicotyledons Plantago maritima Agrostis capillaris olata Thymus praecox Empetrum nigrum cinerea replaced here by nigrum nant with Erica tetralix sub-community This type of heath shares several features with H7c; multiflora are rare. corniculatus Hypochoeris radicata rare on the moist soils. This sub-community is found predominantly in northern Britain. Empetrum nigrum with decumbens sis T and is is The . and Anthoxanthum odoratum frequent and is Hypochoeris radicata lanceo- are very

, Erica tetralix and P. occasional. Nardus Festuca rubra Plantago maritima , Erica cinerea sub-community H7c as the usual com- constant with Danthonia decum- Salix repens Empetrum nigrum Festuca ovina Plantago maritima Calluna vulgaris. Succisa pratensis Erica cinerea frequency but common. very conspicuous. Agrostis capillaris Carex nigra and and common. Agrostis capillaris wo features distinguish this as the most abundant species and panion to canopy is typically extensive, but short because of grazing. although grasses are Secondly, prominent often replaced by Anthoxanthum odoratum Danthonia decumbens much reduced and replaced by Erica tetralix common and sometimes co- dominant. lata This sub-community is most prominent on the north-west coast of Britain, particularly in the Hebrides and Sutherland, with scattered occurrences down to Anglesey. Erica tetralix T type of heath. First, among the sub-shrubs often abundant with Molinia caerulea occasional and frequent bens Erica tetralix locally prominent. stricta

89 H8 Calluna vulgaris – Rhytidiadelphus squarrosus and Pleurozium schreberi are more occasional. In more open Ulex gallii heath situations, or on burned or disturbed bare ground, mosses such as Campylopus paradoxus, Poly- Floristically this is a diverse community with only trichum piliferum or P. juniperinum can become three constants overall, namely Calluna vulgaris, abundant along with lichens species such as Erica cinerea and Ulex gallii. Erica tetralix, Cladonia impexa and C. squamosa. Molinia caerulea and Agrostis curtisii are typical- This community is found on free-draining, ly lacking from this community. Often the three generally acid to circumneutral soils, in the warm constant sub-shrubs are co-dominant, but propor- oceanic regions of lowland Britain. It can be found tions are variable and where E. cinerea is reduced over a wide range of arenaceous sedimentaries and Vaccinium myrtillus can appear. On disturbed acid igneous and metamorphic rocks as well as on ground U. europaeus may be abundant and both silty and sandy superficials like loess and aeolian Pteridium aquilinum and Rubus fruticosus agg. sands. The superficial pH underneath this com- may appear in the heath. munity is usually from 3.5 to 4.5. It occurs Typically sub-shrub cover is high and herbs are throughout south-western England and Wales, on sparse, but often the bushes are separated by the Isle of Man and, more sporadically, in the grassy runnels, a feature accentuated by grazing. southern Pennine fringes and the East Anglian The most frequent grasses are Agrostis capillaris coast. and Festuca ovina with A. canina ssp. montana, Local climatic and edaphic conditions influence F. rubra, Anthoxanthum odoratum and Danthonia floristic variation; grazing by rabbits, sheep or decumbens occasional to frequent. Deschampsia cattle, and sometimes burning (which is normally flexuosa and Nardus stricta are much more patchy an accidental occurrence), affect physiognomy and in their occurrence. There is often some Potentilla composition. The community is maintained against erecta and Galium saxatile, and much more succession to woodland in most situations by graz- occasionally Teucrium scorodonia and Polygala ing and burning, although in some situations expo- serpyllifolia. Additional herbs are characteristic of sure to the wind prevents the establishment of particular sub-communities. woody invaders such as Betula spp. and Quercus In general bryophytes and lichens are not spp. Much former heath has been improved for numerous or diverse. There may be some Hypnum agriculture and it now often survives as patches on cupressiforme and Dicranum scoparium, and marginal grazing land.

90 and Ulex Festuca Where , reduced to Hypnum H8a remains common ubra Pteridium aquil- or F. r Potentilla erecta and may expand. Cryptogams accinium myrtillus Galium saxatile. V Agrostis capillaris the canopy is opened by disturbance or burning europaeus inum are generally infrequent with a few patches of cupressiforme. This sub-community occurs throughout the range of H8. ovina small tufts with occasional and weak and Erica cinerea but Species-poor sub-community There is an extensive and dense The canopy sub-shrub canopy. can be quite tall, thicker stands being less penetrable to live- stock. The associated flora is very sparse with grasses such as other species listed opposite scarce. is prefer- frequent can also Grasses with and Pleurozium Calluna Festuca are occasion- , , Species listed opposite usually very scarce. H8e Rhytidiadelphus is present with reduced in fre- accinium myrtillus can be quite common, V can form a lush occasional. open situations Anthoxanthum all frequent, but Ulex gallii and and, strongly diagnostic, Nardus stricta and Galium saxatile Nardus stricta accinium myrtillus. accinium myrtillus occur with local abundance but dicotyledonous associates are few. Digitalis purpurea al. In more bryophytes but patchy cover. This sub-community is found mainly in the upland fringes. can have a high cover, with can have a high cover, Agrostis capillaris reduced frequency, though it reduced frequency, can remain locally abundant in this upland sub-community. The most prominent sub-shrub is usually smaller amounts of V V sub-community Erica cinerea vulgaris Erica cinerea quency but Deschampsia flexuosa ential. ovina odoratum and schreberi squarrosus constant in small amounts with Deschampsia flexuosa , Potentilla erecta but other species listed opposite are scarce. the is more and frequent. H8d sub-community Plantago maritima , Potentilla erecta Festuca ovina can occur frequently H8 Scilla verna. Plantago most frequent, and often the grass. only, remains common while Hypochoeris radicata distinctive and preferential with maritima and may be abundant in a grazed sward. This sub-community is con- fined to the coastal fringe in western Britain. Hypochoeris radicata Thymus praecox Scilla verna The three constant sub-shrubs are typically extensive as co- dominants. There is a rather species-poor herbaceous ele- ment with Scilla verna are Erica Agrostis and Anthox- iola lactea is also typi- Festuca V , Festuca ovina H8b Agrostis canina mon- Ulex gallii and Danthonia decumbens Potentilla especially abundant, and . Mixtures of these species and Carex pilulifera capillaris Danthonia decumbens sub-community The canopy is well-developed here with cinerea but not as dense in H8a and typically there is a system of grassy runnels. In these quite frequent but more charac- teristic is and less commonly anthum odoratum Combinations of species listed opposite not present. rubra typically form the bulk of a rough cover between the bush- es. though particu- cal but patchy, larly abundant in open places after burning, and can also become prominent in such places. This sub-community occurs throughout the range of H8 but is better represented in the west. tana fre- , Festuca rubra , Galium . frequent. Linum Carex flac- , , erecta Danthonia decumbens, Anthoxanthum odoratum H8c Brachypodium syl- , Hypericum pulchrum Plantago lanceolata , Lotus corniculatus , Stachys betonica and Helianthemum nummulari- , ith them, however, is a group ith them, however, and vaticum catharticum Carex caryophyllea ca um quent, with occasional verum Sanguisorba minor sub-community This is the most striking of sub-communities, developing on more calcareous soils. The sub-shrubs and structural varia- tion are similar to those of H8b. W of strongly preferential herbs, listed above. Where numbers of these are present in grazed stands the vegetation can look like Mesobromion grassland growing among islands of the heath sub-shrubs. This sub-community is found in areas with calcareous bedrock mantled with drift. Sanguisorba minor

91 H9 Calluna vulgaris – dontium lineare may be frequent. On exposed soil there can be locally abundant Polytrichum juniper- Deschampsia flexuosa heath inum, P. piliferum and P. commune. Among leafy hepatics Gymnocolea inflata is particularly charac- Calluna vulgaris is almost always the most teristic. The commonest lichens are Cladonia abundant plant in this community, often forming a chlorophaea, C. floerkeana, C. squamosa, C. coni- fairly low and open canopy. Where burning is ocraea and C. fimbriata. frequent, the individuals are immature and stands This heath is the characteristic sub-shrub are uniform in age. No other sub-shrubs are vegetation of acid and impoverished soils at low consistently frequent throughout, although some to moderate altitudes through the Midlands and can be quite common and locally abundant. northern England. It is normally found on very Vaccinium myrtillus is the most important, base-poor soils with a surface acidity generally of particularly at higher altitudes. More locally pH 3-4, highly oligotrophic and at least moderate- V. vitis-idaea and Empetrum nigrum ssp. nigrum ly free-draining, often excessively so, which have can be found. Erica cinerea, E. tetralix and Ulex been derived from a wide variety of parent materi- gallii by contrast are very scarce. als. It is found mainly in the southern Pennines The only other vascular constant is and North York Moors with more local occur- Deschampsia flexuosa, although even in open rences scattered through the Midland plain. heather it often occurs only as sparse tufts, and The cool and wet climate has some influence under dense canopies it can almost disappear. on the floristics of this community, but much of its Molinia caerulea can become frequent on moister character derives from a combination of frequent ground, but Agrostis capillaris, Holcus lanatus, burning and grazing. Also the heavy atmospheric H. mollis and Festuca rubra only occur occasion- pollution in the areas in which this heath occurs ally. Other herbs are also few and are of low cover. is thought to inhibit bryophyte and lichen diversi- Galium saxatile and Potentilla erecta are frequent ty of the community. The community has been in grazed stands and Juncus squarrosus and reduced considerably in extent. In the lowlands Pteridium aquilinum occasionally occur. Seed- large tracts of heath have been reclaimed for agri- lings of Quercus spp., Betula spp. and Pinus culture whilst other areas have been lost to inva- sylvestris may be seen but rarely survive to the sion by trees after the neglect of traditional treat- sapling stage due to frequent burning and grazing. ments. Furthermore, both in the lowlands and The bryophyte and lichen flora is characteristic, around the upland fringes, the community has although poor in species. Hypnum cupressiforme been replaced with coniferous plantations, or s.l. is restricted, but Pohlia nutans is constant and land use changes have led to the spread of very common with occasional Campylopus U20 Pteridium aquilinum – Galium saxatile paradoxus and Dicranum scoparium. Ortho- community.

92 , sub- and and are the all show is Deschampsia Pohlia nutans. and accinium H9c V Pohlia nutans may be often the only plants, Calluna vulgaris accinium myrtillus Deschampsia flexuosa only constants, and in frequent- ly burned heather even the latter can almost disappear. V Calluna vulgaris flexuosa with occasional Species-poor sub-community In this, the most impoverished form, occasional. community are the usual forms in the southern Pennines and Moors, and are the North York widespread and sometimes extensive over heathlands that are still frequently burned. Campylopus paradoxus Orthodontium lineare reduced frequencies compared with H9b. This and the absent. is , Deschampsia flexuosa abundant but not with associ- ates listed opposite. and in its The growing common are both Molinia and Campylopus Molinia caerulea and and H9a Dicranum scoparium Pohlia nutans Calluna vulgaris Galium is typically strongly at most occasional, and accinium myrtillus Hypnum cupressiforme sub-community Calluna dominant but exceptionally the bushes tend to be large and mature or even degenerate. V and sometimes abundant. Pteridium aquilinum occasional and there are fre- quent, even dense tufts of Deschampsia flexuosa. mosses are most distinctive; Hypnum cupressiforme s.l. unusually common and abun- dant with also preferential and frequently rivalling Hypnum cupressiforme Dicranum scoparium cover. Apart from occasional cover. Hypogymnia physodes on older lichens are very few. This sub-community is mainly found on wetter soils, and along with the sub-communities, is primarily found on lowland sites where burning is no longer practised. accinium myrtillus V other species listed opposite rare. paradoxus often Potentilla Galium Hypnum frequent and Commonly Holcus mol- and remains sub-community Pohlia nutans Rumex ace- Galium saxatile H9d ; Rumex acetosella Deschampsia Molinia and scattered ,and stands are locally with Holcus mollis Festuca rubra. H9 Potentilla erecta Hypnum cupressiforme occur more than very or Galium saxatile Calluna vulgaris constant but is often rivalled in cover by flexuosa enriched by a little lis Deschampsia flexuosa especially abundant with occa- sional Festuca rubra and with occasional tosella. there are scattered plants or prominent patches of saxatile erecta on bare areas. Lichens and hepatics are sparse and among the mosses only and s.l. occasionally. This sub-community is mainly found on wetter soils, and along with the sub-communities, is primarily found on lowland sites where burning is no longer practised. Hypnum Pohlia Molinia constant at and H9e Campylopus para- The ground layer, Deschampsia flexuosa Galium is generally very abun- and sub-communities, is primarily found on lowland sites where burning is no longer practised. doxus. This sub-community is mainly found on wetter soils, and along with the Molinia caerulea sub-community Calluna dant, but is frequently accompanied by small amounts of caerulea. is poorly developed however, with just very sparse nutans low cover. Molinia caerulea all inter- ,

, V. , – or, more or, , , Pohlia C. squamosa. H9b and Empetrum nigrum vitis-idaea spp. sub-community

or Campylopus paradoxus V. , Deschampsia flexuosa Orthodontium lineare accinium myrtillus accinium myrtillus Cladonia chlorophaea C. floerkeana V medium Barbilophozia floerkii common or locally abundant with occasional to frequent Campylopus paradoxus Gymnocolea inflata V locally, locally, Cladonia This is the richest sub-commu- nity characterised by younger often canopies of heather, recovering from burning. There are frequently one or more of the sub-shrubs listed above. Often Among has a rather low cover. the sub-shrubs, bryophytes are more varied than in any other type of this heath. nutans and occur frequently and the leafy hepatics and lichens listed above are occasional to fre- quent. This and the species-poor sub- community are the usual forms in the southern Pennines and Moors and are the North York widespread and sometimes extensive over heathlands that are still frequently burned.

93 H10 Calluna vulgaris – Erica species can develop. In exposed stands there is often a patchy carpet of Racomitrium lanuginosum cinerea heath and fruticose lichens. However, more important than these species in the community as a whole are This community is typically dominated by bulky pleurocarpous mosses such as Hypnum Calluna vulgaris, but the cover, height and cupressiforme s.l., Pleurozium schreberi and structure of the sub-shrub canopy vary markedly Hylocomium splendens, with Rhytidiadelphus tri- depending on the intensity and timing of burning quetrus and R. loreus also occurring occasionally. and grazing. Erica cinerea, a constant, is frequent These species, with Dicranum scoparium, become but generally subordinate to heather and persists abundant with the maturing and opening up of the below taller Calluna canopies. Vaccinium Calluna bushes. myrtillus, by contrast, is at most occasional and This heath is characteristic of acid to circum- V. vitis-idaea is scarce. Empetrum nigrum ssp. neutral and generally free-draining soils in the nigrum can occur, but mainly in sub-community cool oceanic lowlands and upland fringes of H10b. The restricted occurrence of these northern and western Britain. The soils on which sub-shrubs is a contrast with Calluna vulgaris – this community is found can be quite moist as a Vaccinium myrtillus heath (H12). result of the climate and the superficial pH Apart from the abundance of the two constant beneath the community can be anywhere between sub-shrubs there are two other distinctive floristic 3.5 and 6. It occurs widely through the more features of this type of heath. These are firstly the oceanic parts of Scotland, with outlying stands in high frequency of grasses and to a lesser extent Wales, western England and around the east- sedges and dicotyledons, and secondly the central Highlands. striking contribution that the ground layer makes In more exposed situations it may be considered to this community. Deschampsia flexuosa is the as an edaphic or climatic climax, but often most consistent grass throughout, with Agrostis burning and grazing are important in controlling its canina and Nardus stricta occasional to frequent. composition and structure. Steady grazing pressure In certain sub-communities Festuca ovina, pushes the vegetation towards the Festuca ovina – Anthoxanthum odoratum, Agrostis capillaris and Agrostis capillaris – Galium saxatile grassland (U4) Molinia caerulea become very common. Carex or, over more base-rich soils, the Festuca ovina – binervis and C. pilulifera are very characteristic of Agrostis capillaris – Thymus praecox grassland this community. After burning, mixtures of these (CG10). After fire, heavy grazing can precipitate a plants can become patchily abundant and run-down of the heath to swards in which Nardus Deschampsia flexuosa and C. pilulifera temporar- stricta or Juncus squarrosus play an important part ily dominant. There are typically only a few or permit the spread of Pteridium aquilinum. dicotyledons, but Potentilla erecta is a Release from grazing and burning, in all but the constant and Galium saxatile is fairly common. most exposed sites, would theoretically permit pro- After burning, a local abundance of Polytrichum gression to scrub and woodland, although in many piliferum, P. juniperinum and encrusting Cladonia areas natural seed parents are now scarce.

94 is very Erica and Juncus and occa- nigrum Carex Erica cinerea Juncus squarro- Molinia ssp. is occasional and is well represented. and is preferential and dicotyledons are H10a is typically dominant , very common at low and occasional Potentilla erecta Sphagnum capillifolium Deschampsia flexuosa , Calluna scarce. Monocotyledons are Scirpus cespitosus Diplophyllum albicans cal sub-community Empetrum nigrum and sional at most and caerulea covers with frequent binervis squarrosus. Campylopus para- doxus and occasional to frequent. accinium myrtillus Typi In this, the most species-poor sub-com- munity, and abundant in pioneer building regrowth after burning. very frequent and can be prominent. V Empetrum nigrum tetralix few with frequent and sometimes prominent. Molinia caerulea patchily abundant with occasional Scirpus cespitosus sus. Carex binervis Apart from Galium saxatile very sparse. The ground layer is also poor in species and of low cover. This sub-community is found through- out the range of H10. s.l. is rare, nigrum nigrum other grasses Combinations of such species rare. is frequent, Carex pilulif- spp. Scirpus ssp. and is the usual occasional and occasional Racomitrium lanugi- Carex panicea Carex binervis Potentilla erecta common and H10b is preferentially com- patchily prominent Erica cinerea Hypnum cupressiforme C. panicea. Scirpus cespitosus C. pilulifera the most abundant moss, and Calluna vulgaris Empetrum nigrum and Empetrum nigrum quite common and and often abundant among degener- ating bushes with patches of Cladonia uncialis C. impexa. cespitosus with frequent Huperzia selago. Racomitrium lanuginosum Deschampsia flexuosa estern Isles and Shetland. accinium myrtillus Racomitrium lanuginosum sub-community This is found on exposed sites where the sub-shrub canopy is more open and dominant. V and is preferential and quite common. Grasses are sparse with scattered tufts of very occasional. its place being taken by era is also frequent. is the only frequent dicotyledon Huperzia selago mon. There are substantial areas of the ground layer with nosum frequent Lichens are well represented. This sub-community is typical of the W H10 , are Galium Hylocomium and , Dicranum C. pilulifera , is still abundant but H10c Anthoxanthum – and may often be co-domi- ubra and also sub-community F. r , are both very common with Hypnum cupressiforme s.l. and Potentilla erecta Succisa pratensis and occasional Pleurozium schreberi occasional records for several species . Bulky pleurocarpous mosses are con- sistent and distinctive here with fre- quent splendens scoparium. This sub-community is common in south-west Scotland. saxatile also common. Dicotyledonous herbs are more numerous than in 10a and 10b. Combinations of such species rare. nant. The sub-shrubs are usually short, commonly forming a mosaic with grassy turf. Most frequent here are the grasses and other species listed above. Carex binervis Festuca ovina odoratum Calluna vulgaris Erica cinerea patchy. , Festuca ovina Anthoxanthum odora- , and , Carex Among Galium saxatile Pleurozium schreberi , eferentials, very and Hypericum pulchrum. Dicranum sco- Primula Agrostis capillaris tum Sub-shrub canopy often short in a grassy heath with frequent Hylocomium splendens Campanula rotundifolia and parium and on relatively base- Carex pulicaris Rhytidiadelphus – Calluna vulgaris H10d Dicranum scoparium Breutelia chrysocoma additional pr

structural importance. both able to show promi- Linum catharticum Thymus praecox. , Carex pulicaris, Viola and and vulgaris. Prunella vulgaris riviniana Danthonia decumbens common with occasional to frequent are frequent. This sub-community is local in occurrence but can be found on Skye, Rum and Uist scattered localities through the Highlands and Southern Uplands. the bryophytes triquetrus and the pleurocarps remain very com- mon; additionally making this the most species-rich sub- The species listed above community. are most frequent together with panicea Thymus praecox sub-community This heath is found rich brown earth soils and is very sim- ilar to H10c with Erica cinerea nence and with herbs bryophytes both being of Here there are

95 H11 Calluna vulgaris – There may be hypnoid mosses such as Hypnum cupressiforme s.l., Pleurozium schreberi, Hylo- Carex arenaria heath comium splendens and Rhytidiadelphus tri- quetrus in the turf. On areas of bare ground acro- Calluna vulgaris is the only constant sub-shrub carps such as Polytrichum juniperinum, P. pilifer- found in this community and is often abundant, um and Ceratodon purpureus may be patchily although cover may be discontinuous and patchy abundant. in younger or grazed stands. Other frequent This is the characteristic sub-shrub vegetation sub-shrubs are Erica cinerea and Empetrum of stabilised, base-poor sands on dunes and plains nigrum ssp. nigrum, and each can be locally around the coasts of Britain. The heath is largely abundant, to the exclusion of Calluna itself. confined to sands with a pH of less than 5 and can Sometimes Rosa pimpinellifolia is plentiful, and only establish on sediments with surface stability together with Erica tetralix and Salix repens is such as found on older dunes and on consolidated found in transitions to wetter heath. sand plains. It is very local along the coasts of Carex arenaria is constant, but no more than western England and Wales, becoming commoner moderately abundant and often senile, except in Scotland. where the sand is locally mobile. Ammophila The community develops in primary succession arenaria is also frequent throughout, though by colonising fixed dune grasslands on acid sands usually sparse. In more species-poor stands these or where more lime-rich sands have become may be the only species, but often there is some leached. Relief from grazing is probably important Festuca rubra (or F. ovina) with Agrostis capillaris for its establishment but once established predation and Anthoxanthum odoratum and less commonly by herbivores, along with variation in regional cli- Poa pratensis. Variation among dicotyledons is mate and substrate, influences its composition and modest, but Galium verum, Lotus corniculatus, structure, and ultimately, grazing maintains the Viola riviniana and Thymus praecox all occur community against reversion to grassland or pro- quite frequently with several other herbs. gression to scrub and woodland.

96 Carex Dicranum and is overwhelmingly Anthoxanthum H11c remains constant Deschampsia or Other herbs are also Calluna vulgaris Species-poor sub-community Calluna vulgaris dominant with only occasional or even no bushes of other species. Carex arenaria but grasses may only be represented by a few tufts of odoratum flexuosa. sparse. Bryophytes may include hypnoid species and scoparium. This sub-community can be found throughout the range of H11. The associates listed opposite are all scarce in impoverished mixtures of arenaria. only and C. impexa nigrum Empetrum Hypnum Empetrum very frequent. and Luzula ssp. Aira praecox and Agrostis capillaris H11 Ptilidium ciliare. and H11b Pleurozium schre- , , and with other species as which forms large patches, Festuca rubra/ovina , Rhytidiadelphus triquetrus Galium saxatile Hylocomium splendens , Erica cinerea occasional at most, but nigrum and Cladonia arbuscula can be patchily prominent but stretches of lichen-rich turf are not characteristic. Empetrum nigrum sub-community Calluna vulgaris nigrum are the co-dominants here, especial- ly in the cooler wetter north of Britain. remains common among frequent Carex arenaria campestris listed above. Hypnoid mosses are more prominent with cupressiforme beri and less commonly Lichens are more patchy. This sub-community is found local- ly in north and east Scotland. and , and Aira species. in an , sometimes Festuca Other herbs are also com- common Peltigera cani- Empetrum are rare. sub-community Usnea Carex arenaria Agrostis capillaris Rosa pimpinellifolia H11a , C. foliacea Calluna vulgaris C. pyxidata constant and are generally co-domi- , Cladonia furcata is very common with and Erica cinerea spp., including those listed Empetrum frequent but Cornicularia aculeata Galium saxatile Luzula campestris. and low-growing Erica cinerea praecox nigrum rubra/ovina scattered shoots of and is a distinctive invader. is a distinctive invader. colonising first. Erica cinerea sub-community This sub-community is prominent in southern areas where rainfall is relatively low. Erica cinerea nant with and some of C. floerkiana Dicranum scoparium and mon, sometimes with This is the most widespread sub- community but it is replaced local- ly by the in north and east Scotland. are occasional. The distinctive element is the cryptogams, often occupying the bulk of ground. Hypnoid mosses are scarce and most obvious are the lichens, particularly Cladonia above. Hypogymnia physodes na C. gracilis often extensive carpet of lichens.

97 H12 Calluna vulgaris – lichens and Polytrichum species can be abundant in the years following burning. Vaccinium myrtillus heath This community is the typical sub-shrub community of acidic to circumneutral, free-draining This heath is generally dominated by Calluna mineral soils throughout the cold and wet sub-mon- vulgaris and includes most of the Calluneta from tane zone generally between 200 m and 600 m. The less oceanic sub-montane areas where burning is soils on which it occurs are widespread throughout commonly practised, including many grouse this zone, developing from a variety of siliceous par- moors. Here a predominance of building-phase ent materials, intrusive igneous rock or coarse glacio- Calluna is found, but a more open cover of degen- fluvial gravels. Despite being free-draining the soils erate Calluna can often also be present. Vaccinium are normally moist for the majority of the year myrtillus is constant though it is usually subordi- because of the climate and the superficial pH is usu- nate to Calluna and is most vigorous out of reach ally between 3.5 and 4.5. It is extensive in the east- of grazing animals. Vaccinium vitis-idaea is also central Highlands but also important in south-east found, sometimes with local prominence, and Scotland, the Lake District, parts of Wales and the Erica cinerea may also be present on drier slopes. South-West Peninsula and the North York Moors. In Empetrum nigrum ssp. nigrum is frequent, form- places like the southern Pennines, where air pollu- ing mats after burning, but then becomes reduced tion is severe, it is largely replaced by Calluna vul- after the Calluna has regrown. garis – Deschampsia flexuosa heath (H9). In many stands herbs are rare. Only Burning and grazing are the major influences Deschampsia flexuosa is frequent throughout. on floristics and structure, although climatic and When grazing is regular there may be additional edaphic difference play some part in determining herbs including Festuca ovina, Agrostis capillaris, variation within the community. Successional A. canina, Nardus stricta, Potentilla erecta and developments are usually held in check by Galium saxatile. burning and grazing and without these most The ground-layer is often prominent with stands would probably progress to scrub and bulky mosses characteristic, such as Dicranum woodland. Continuous heavy grazing favours the scoparium, Pleurozium schreberi, Hypnum loss of sub-shrub vegetation to grassland and in cupressiforme s.l. and Hylocomium splendens, some instances, particularly after burning, may together with larger Cladonia species. Encrusting result in the spread of Pteridium aquilinum.

98 is very common, Calluna Empetrum is frequent as and Hypnum jut- overwhelmingly Pteridium aquil- , sub-community H12a and both scarce in rather Pleurozium schreberi Erica cinerea and accinium myrtillus V are quite common. The ground Calluna vulgaris accinium vitis-idaea egetation is typically species-poor V nigrum species-poor heath, usually over- whelmingly dominated by vulgaris. Calluna vulgaris V with occur frequently as scattered shoots. frequent and dominant and other sub-shrubs of low cover. but both only as scattered shoots. Other vascular associates are few. Deschampsia flexuosa scattered shoots and sparse plants of Potentilla erecta inum cover is not extensive and only Dicranum scoparium landicum H12 , C. Herbs , and and especially vitis-idaea

V. Hylocomium Pleurozium , Blechnum spi- Cladonia – and C. uncialis Erica cinerea. , is still the general H12b Potentilla erecta Deschampsia flexuosa Hypnum jutlandicum. often joining and common. sub-community accinium vitis-idaea Bryophytes and lichens are more V accinium myrtillus Empetrum nigrum V Empetrum accinium vitis-idaea Sub-shrub cover extensive and varied with frequent and species listed opposite typically scarce. Cryptogam flora var- ied and often abundant, with bulky pleurocarps prominent, splendens schreberi Cladonia impexa pyxidata impexa This includes most of the richer stands of this heath, which develop a number of years after burning. Although Calluna vulgaris dominant it is frequently accompanied by V are generally sparse with only scat- tered plants of and occasional Juncus squarrosus cant. numerous including the species listed above. and occasionally with Blechnum spicant. and and frequent, with occasional and , is joined Lichens is less Lotus Agrostis capil- , accinium vitis-idaea and occasional Galium saxatile nigrum Juncus squarrosus V can be locally iola riviniana , Festuca ovina V , – not so abundant as H12c Campanula rotundifo- , Lathyrus montanus , Calluna vulgaris Festuca ovina Polygala serpyllifolia. Deschampsia flexuosa Nardus stricta Potentilla erecta , and lia not extensive, often patchy. laris Anemone nemorosa abundant. Bryophytes remain quite varied, but lichens are few and of low cover. Calluna vulgaris usual, and other sub-shrubs of generally moderate cover in a grassy heath, with frequent and Carex pilulifera corniculatus Succisa pratensis by a variety of herbs including those listed above. Where the soils are less species such as base-poor, Galium saxatile sub-community This sub-community is found on better soils and after burning, often followed by grazing. dominant and with other sub-shrubs forms an open growth within a grassy sward.

99 H13 Calluna vulgaris – Cladonia Cornicularia aculeata. Among these, bryophytes arbuscula heath are generally few and rarely of any abundance. Racomitrium lanuginosum is constant and can This heath has a dwarfed mat of sub-shrubs with form locally conspicuous patches. few vascular associates, but with a prominent This heath is the characteristic sub-shrub lichen flora. Calluna vulgaris is the most frequent vegetation of base-poor soils, over exposed ridges species, generally prostrate and forming a carpet and summits of mountains, in parts of Britain with or in wave-like bands or on solifluction terraces. a cold continental climate. It is found on soils Among other sub-shrubs Empetrum nigrum is with a superficial pH of between 4 and 5, and most important, usually as ssp. hermaphroditum, frequently a humic surface above pervious acidic but with ssp. nigrum at lower altitudes. It may be bedrocks and superficials. It is most widespread intermixed in the mat or forming clumps. through the east-central Highlands of Scotland, Loiseleuria procumbens is quite frequent and thinning out westwards into the central Grampians abundant, but Arctostaphylos uva-ursi is at most and north-west Highlands where it is progressive- occasional. Both Vaccinium myrtillus and ly replaced by its oceanic counterpart Calluna vul- V. vitis-idaea are common, but always subordinate garis – Racomitrium lanuginosum heath (H14). in cover. There are a few fragmentary localities in northern The other vascular associates are few and England and Wales. sparse. Deschampsia flexuosa and Carex bigelowii It is a vegetation type of unsheltered slopes are most frequent with species such as Scirpus generally between 600 m and 900 m where there cespitosus, Agrostis canina and Molinia caerulea are almost constant strong winds which frequent- at lower altitudes and Juncus trifidus becoming ly clear the ground of snow and subject the vege- occasional at higher levels. Huperzia selago is also tation not only to reduced precipitation but also to frequent in higher altitude stands. the effects of frequent and severe frosts and subse- Lichens are important structurally. Cladonia quent thaws. Burning and grazing may have cur- arbuscula is especially common and, where there tailed its range in suitable localities in the more is some shelter, may be abundant. It is usually southerly uplands, but in the eastern Highlands mixed with C. rangiferina which locally may be the vegetation seems to be largely unaffected by co-dominant. Also constant are C. uncialis, treatments and the community can be considered Cetraria islandica, Alectoria nigricans and a climax.

100 H13

Vaccinium species common and Vaccinium species less fre- Loiseleuria procumbens frequent in a quent and Loiseleuria nearly prostrate mat, with Cladonia procumbens and listed crispata, C. coccifera, Ochrolechia lichens occasional at most. frigida and Thamnolia vermicularis often found.

H13c Deschampsia flexuosa very com- Deschampsia flexuosa only mon with occasional Diphasium occasional and Carex bigelowii Cladonia crispata – Loiseleuria alpinum and Juncus trifidus. scarce but Erica cinerea and E. procumbens sub-community Cetraria nivalis frequent and tetralix occasional among the Cladonia gracilis and sub-shrubs, sometimes Calluna vulgaris is again the usual C. bellidiflora occasional. with Scirpus cespitosus and dominant, but one or both subspecies Molinia caerulea. Cetraria of Empetrum nigrum are common and nivalis and Cladonia gracilis can be abundant. In the flattened sub- uncommon, but C. arbuscula shrub mat there is a mixed carpet of and C. rangiferina especially lichens including the species listed abundant. above. The herbs comprise scattered H13b shoots of Carex bigelowii, Huperzia selago and Deschampsia flexuosa. Empetrum nigrum ssp. hermaphroditum – Cetraria nivalis sub-community H13a

On bleak exposed sites at higher Cladonia arbuscula – Cladonia altitudes lichens remain abun- rangiferina sub-community dant, but Calluna vulgaris or occa- sionally Empetrum nigrum her- This sub-community is found at maphroditum is dominant. Both lower altitudes or more shel- Vaccinium myrtillus and V. vitis- tered sites where larger Cladonia idaea are more frequent than in species, as above, are especially H13a but usually have low cover. abundant, often exceeding the Loiseleuria procumbens is occa- sub-shrubs in cover. Cladonia sional. Cladonia arbuscula is still impexa can also be found, but the most frequent lichen but is C. gracilis and C. crispata are commonly joined by the species scarce. The most common sub- listed above. Mosses only make a shrub is Calluna vulgaris but minor contribution and the few Empetrum nigrum is vascular associates are present as very common, often as ssp. scattered individuals. nigrum. Vaccinium species are only occasional.

101 H14 Calluna vulgaris – out. Cladonia impexa is frequent at lower alti- tudes and Cladonia gracilis, C. bellidiflora, Racomitrium lanuginosum heath Cetraria islandica and Ochrolechia frigida occur often at higher altitudes. This heath consists essentially of a dwarfed This community is the typical sub-shrub sub-shrub mat with Calluna vulgaris usually community of base-poor soils on windswept predominant, together with Racomitrium lanugi- plateaux and ridges at moderate to fairly high nosum. Other sub-shrubs play a subordinate role, altitudes in the cool oceanic climate of the moun- but may be common. Most frequent is Empetrum tains of north-west Scotland. It can be found up to nigrum, with the two subspecies characterising 750 m, although this can extend up to 1000 m in opposite ends of the altitudinal range (ssp. nigrum the east; to the west and north, on islands like preferentially common towards lower levels and Skye, Orkney and Shetland, it can extend down to ssp. hermaphroditum largely confined to higher below 250 m. The community is found on the altitudes). Erica cinerea is also frequent. base-poor rankers and podzolic soils which are Other vascular associates are few and usually widespread in this region, with a superficial pH scattered. Deschampsia flexuosa, Huperzia between 4 and 5 and a humic surface. It is very selago, Carex pilulifera, Potentilla erecta and much a community of the north-west Highlands Scirpus cespitosus are all frequent, and Carex with scattered occurrences in the central bigelowii becomes common at higher altitudes. Grampians. The extensive woolly carpet of Racomitrium Like its eastern counterpart Calluna vulgaris – lanuginosum which can be up to 5-10 cm thick is Cladonia arbuscula heath (H13) it is found over the most noticeable feature of this community. gentle to moderately steep slopes which are Hypnum cupressiforme s.l. is also very frequent in exposed to fairly constant strong winds that clear some stands, often with several other mosses and the snow which might otherwise provide shelter occasional hepatics. Lichens are common and var- in the coldest months. Although it is sometimes ied but not abundant, and species like Cetraria grazed by sheep and deer, it is unlikely that this nivalis and Alectoria ochroleuca are absent. factor is important in maintaining the characteris- Cladonia arbuscula and C. uncialis are the most tic composition and physiognomy, and this vege- frequent, and Sphaerophorus globosus and tation can be regarded as the natural climax in Cornicularia aculeata are also common through- such exposed situations in its range.

102 and is fre- Carex , sub-com- nigrum and Erica More prefer- Huperzia sela- ssp. , is less common is very common. and Racomitrium Festuca ovina or H14a very common, some- Carex bigelowii or mixtures of the two Arctostaphylos Loiseleuria procumbens C. pilulifera Antennaria dioica Thymus praecox are only occasional and in , Potentilla erecta. Empetrum nigrum hermaphroditum and Cladonia uncialis and Festuca ovina sub-community Calluna vulgaris lanuginosum dominate the vegetation mat with other species playing only a minor role. and cinerea some stands can be prominent. More striking is the variety of herbaceous associates. Deschampsia flexuosa than usual, but go ential are the species listed above. Lichen cover is comparatively low but This and the munity are found at the lowest alti- tudes and most sheltered sites occu- pied by the community. quent with Empetrum nigrum hermaphroditum and herbs lichens listed opposite occasional at most. Agrostis canina times with panicea Euphrasia micrantha. species and the herbs at most occasional. some- Cladonia , Carex and some- Nardus stricta and Empetrum nigrum Erica cinerea Arctostaphylos and bryophytes listed opposite very scarce. remain common. ssp. sub-community Huperzia selago generally abundant H14b , Ochrolechia frigida. Cetraria islandica are very frequent and and Racomitrium lanuginosum Carex pilulifera Diphasium alpinum gracilis times co-dominant but often subordi- nate. The variety of herbs characteris- tic of H14a is not found although Deschampsia flexuosa bigelowii Potentilla erecta and Most distinctive are the cryptogams with several pleurocarpous mosses and the typical lichen flora of community with additional species, including those listed above. This is the typical form of this sub- community and is found at the highest altitudes of the range H14. times with an extensive lichen cover, including Empetrum nigrum hermaphroditum Calluna vulgaris with Empetrum nigrum hermaphroditum constant with frequent and H14 and , and at and Molinia constant with and nigrum make their frequent. sub-community Racomitrium Empetrum nigrum ursi is very scarce. In - , ssp. Dicranum scopari- Erica cinerea is common together and H14c retain the representation Carex binervis Festuca Erica cinerea. Scirpus Dicranum scoparium Among the vascular associ- common with Arctostaphylos uva-ursi and A. alpinus and Carex bigelowii and larger pleurocarps such as ates A. alpinus. are found at the lowest altitudes and most sheltered sites occupied by the community. the bryophyte mat um Hypnum cupressiforme s.l. Pleurozium schreberi biggest contribution. In the lichen flora Cladonia impexa with the community species. This and the their peak of frequency, and locally their peak of frequency, abundant of H14b but the sub-shrubs are more varied with Empetrum nigrum Arctostaphylos uva sub-community Calluna vulgaris lanuginosum Pleurozium schreberi nigrum Diplophyllum albicans Arctostaphylos uva-ursi frequent cespitosus caerulea occasional.

103 H15 Calluna vulgaris – Juniperus H16 Calluna vulgaris – communis ssp. nana heath Arctostaphylos uva-ursi heath

Prostrate juniper, referable to Juniperus communis Although Arctostaphylos uva-ursi is found as an ssp. nana, is occasional in a wide variety of sub- occasional in a variety of heath types, it is most shrub heaths. Here, however, it is consistently often found in this community, which has a dis- dominant in the sub-shrub mat, accompanied by a tinct boreal character. Calluna vulgaris is always small but distinctive group of oceanic hepatics. present and is the most usual dominant, forming a The mat is generally less than 10 cm high, fairly canopy 20-40 cm high and having a substantial continuous in the best stands, but it may form a total cover. Arctostaphylos uva-ursi is constant mosaic with islands of vegetation on tracts of bare and can become modestly abundant in gaps with- rock and debris. Several other sub-shrubs are well in the heather cover. Erica cinerea is also very represented: Calluna vulgaris and Erica cinerea common but of low cover. In many stands there is are especially frequent and the former often fairly some Vaccinium myrtillus and V. vitis-idaea. abundant. Arctostaphylos uva-ursi and A. alpinus Quite commonly there are small amounts of are less common, and Empetrum nigrum ssp. her- Genista anglica, but herbaceous associates are few maphroditum is occasional. except in the Pyrola media – Lathyrus montanus Vascular associates are typically few and are sub-community. The only constant grass is usually scattered in the mat. Deschampsia flexuosa, Deschampsia flexuosa and this can be joined by Scirpus cespitosus and Potentilla erecta are constant, Luzula multiflora and L. pilosa. with Huperzia selago, Solidago virgaurea, Dactyl- Bryophytes are variable, with the bulkier moss- orhiza maculata, Polygala serpyllifolia, Succisa es often strongly associated with particular stages pratensis, and Antennaria dioica more occasional. in the heather regeneration cycle. Hypnum In some stands the cryptogam flora is similar to jutlandicum, Pleurozium schreberi and Dicranum other kinds of dwarfed sub-shrub heath. In typical scoparium, however, are very common overall and examples of this community, however, the species Hylocomium splendens is also a constant through Racomitrium lanuginosum, Cladonia uncialis, C. imp- much of the community. exa, Sphaerophorus globosus and Cornicularia Lichens also differ in their representation, with aculeata, which are common in all these other only Cladonia impexa constant and, in many kinds of heath, are joined by Pleurozia purpurea, stands, of low cover. Fruticose species such as Frullania tamarisci and Diplophyllum albicans which C. arbuscula and C. rangiferina tend to follow the are not. Where the sub-shrub canopy is well-devel- larger pleurocarps in developing among the more oped the total cover of the cryptogams is much less shady and humid conditions of older heather than in the typical moss-heaths of the region. canopies. Hypogymnia physodes and, less com- This heath is confined to humic rankers at monly, Cetraria glauca can be seen on decaying moderate altitudes in the cool oceanic climate woody stems. along the western seaboard of the north-west This heath is characteristic of base-poor to cir- Highlands and some of the Western Isles. Soil cumneutral soils at moderate altitudes, generally development under this community is typically between 250 m and 600 m altitude, in the cold rudimentary with just shallow accumulations of continental climate of the east-central Highlands decaying juniper and bryophyte litter on Cambrian of Scotland. It is found on a variety of acid quartzite screes. Although perhaps once more soils developed from lime-poor parent material. It widespread throughout the north-west Highlands, occurs widely but fairly locally through the the community is now of rather patchy occurrence east-central Highlands with especially good along the western side of the more northerly moun- representation in Speyside. tains with especially good stands on Beinn Eighe The community forms an important part of and Foinaven. The community is replaced in the grouse-moor in the central Highlands and although continental climate of the east-central Highlands by edaphic differences play some part in determining the Juniperus communis ssp. communis – Oxalis floristic variation in the community, their effects acetosella woodland (W19). are often overlain and modified by the influence It is confined to the lower portion of the altitu- of burning which ultimately maintains this vege- dinal ranges of the other dwarf sub-shrub heaths tation as a plagioclimax. Stretches of moorland and, although the vegetation mat is typically blown including stands of the community are often open clear of snow, is not usually found in the kind of to livestock but there is little information on the severely exposed situations of which the other impact of grazing on this vegetation. communities are so characteristic. This communi- ty is given some protection against the effects of grazing by the rocky ground on which it is typical- ly found, but it is readily damaged by burning.

No sub-communities.

104 is and Peat- vitis-

and C. flo- , V. Calluna species C. squamosa. and Carex pilulifera are very remain frequent and absent, and C. impexa Pohlia nutans. , H16c Erica cinerea occur frequently. occur frequently. Cladonia Hypnum jutlandicum subor- Empetrum nigrum spp. sub-community Arctostaphylos uva-ursi C. coccifera is more often overwhelmingly , and accinium myrtillus Cladonia Although sometimes quite abundant, vulgaris dominant. Both Genista anglica The herbs of sub-community H16a are hardly ever found. Among the bryophytes the characteristic mosses Hylocomium splendens Pleurozium schreberi but patchy, Dicranum scoparium often with a little encrusting lichens are most noticeable, particularly the listed above. erkeana V idaea scarce, and hypnoid mosses patchy. Scirpus cespitosus common and lichens extensive on areas of bare ground with frequent Cladonia uncialis usually a strong domi- , Arctostaphylos uva-ursi is usu- Festuca species. in a sparse Hylocomium L. pilosa , accinium remains con- Potentilla V also frequent. , and – Calluna vulgaris dinate and associates listed opposite occasional at most. nant with Cladonia arbus- commonly are occasional. Cladonia Empetrum nigrum H16b vitis-idaea

Calluna vulgaris V. Hypnum jutlandicum sub-community often abundant. Larger C. rangiferina intermingled. Hypnoid mosses Luzula multiflora Carex pilulifera , , and Listera cordata accinium myrtillus accinium myrtillus splendens lichens are also more apparent including several Pleurozium schreberi and Cryptogams, however are more diverse and extensive with the bulky pleurocarps V vitis-idaea Arctostaphylos uva-ursi stant here but ally dominant and with the sub-shrubs mentioned above. In contrast with H16a, herbs are scarce though ovina erecta V accompanies understorey with nigrum often extensive with cula H16 , Lotus rientalis and T Potentilla , Erica and The rich , is fairly is most promi- often exten- species are species. iola riviniana together with V Hypericum pul- , , H16a Calluna vulgaris. Lathyrus montanus – common with frequently joining accinium can have a high cover accinium V V Agrostis capillaris Galium saxatile Genista anglica Calluna vulgaris , and Anemone nemorosa Pyrola media , , cinerea Festuca ovina occasional Lathyrus montanus Anthoxanthum odoratum. herb flora includes frequent erecta Pyrola media sub-community Arctostaphylos uva-ursi on less nent in this sub-community, acidic brown earth soils, forming a patchwork with Erica cinerea and the two common. frequent. The most striking feature is the associated herb flora developed in more mesotrophic conditions. Grasses are more common with Festuca ovina Deschampsia flexuosa the herbs listed above. The mosses characteristic of H16 are common, but not abundant, including the preferential Rhytidiadelphus triquetrus. europaea corniculatus. Arctostaphylos uva-ursi sive with chrum

105 H17 Calluna vulgaris – aculeata, Alectoria nigricans and Sphaerophorus globosus. Mosses are not abundant. Racomitrium Arctostaphylos alpinus heath lanuginosum is constant, though in small amounts, and Hypnum jutlandicum becomes Arctostaphylos alpinus occurs with some frequent at lower altitudes. frequency in various kinds of dwarfed sub-shrub This heath is the typical climax sub-shrub heath, but is most typical of this community vegetation of rather base-poor moder soils over where it is a constant, although usually a subordi- very exposed ridges and crests at moderate to nate one, in the woody mat which is normally less fairly high altitudes in the cold and humid climate than 10 cm tall. It is usually dominated by stunted of the mountains of north-west Scotland. It is bushes of Calluna vulgaris with stretches of bare found at higher altitudes than the Calluna stones between. Empetrum nigrum ssp. hermaph- vulgaris – Racomitrium lanuginosum heath (H14) roditum is strongly preferential to higher altitudes which has a similar distribution, and its normal and ssp. nigrum is largely confined to lower situa- range is between 500 m and 750 m, although it can tions. Loiseleuria procumbens is characteristically exceptionally be found up to 900 m, and down to found with E. nigrum ssp. hermaphroditum, and 250 m along the north Scottish coast and on Erica cinerea with E. nigrum ssp. nigrum. Orkney. It is typically found on humic poor Vaccinium myrtillus is common throughout but rankers and more occasionally mature podzolised other Vaccinium species are scarce. soil that have been derived from a variety of There are few herbs. Huperzia selago is the lime-poor parent materials. This community is commonest and a constant, and is often accompa- confined to the north-west Highlands, the north nied, at higher altitudes, by Diphasium alpinum, Scottish coast and Orkney. Carex bigelowii and Antennaria dioica. Desch- The community may be lightly grazed by ampsia flexuosa is also frequent throughout, sheep and deer but this probably has little effect though more so at lower altitudes where Potentilla on its floristics or physiognomy. The inhospitable erecta, Scirpus cespitosus and Carex pilulifera environment and the harsh conditions maintain occur most commonly. the vegetation as a climax. Burning is very delete- More conspicuous are the lichens which form a rious and may cause damage from which recovery patchy mosaic. Cladonia arbuscula and C. unc- is extremely slow if not impossible. Burning may ialis are constant. Preferential to higher altitudes have eliminated this community from many sites are Cetraria glauca, C. islandica, Cornicularia throughout its range.

106 H17

Empetrum nigrum ssp. hermaphrodi- Loiseleuria procumbens occasional, tum and Loiseleuria procumbens but Empetrum nigrum ssp. hermaphro- constant with frequent Carex bigelowii, ditum replaced by ssp. nigrum and Diphasium alpinum, Antennaria with Erica cinerea becoming common. dioica, Cladonia uncialis, C. arbuscula, Potentilla erecta very frequent with C. gracilis, C. pyxidata, C. bellidiflora, Scirpus cespitosus and stricta often Cetraria glauca, C. islandica, Alectoria present. Cladonia uncialis and nigricans and Sphaerophorus globosus. C. arbuscula remain common but lichen flora not so varied or abundant.

H17a H17b

Loiseleuria procumbens – Empetrum nigrum ssp. nigrum Cetraria glauca sub-community sub-community

In this distinctive sub-community Calluna vulgaris dominates the mixtures of Calluna vulgaris sub-shrub mat with Arctostaphylos with subordinate Arctostaphylos alpinus constant and Empetrum alpinus, Loiseleuria procumbens nigrum ssp. nigrum and Erica cinerea and Empetrum nigrum ssp. as common associates. Vaccinium hermaphroditum make up the bulk myrtillus is again sparse with of the mat with scattered Vaccinium occasional Arctostaphylos uva-ursi. myrtillus and occasional V. vitis-idaea, Carex bigelowii is less common and Arctostaphylos uva-ursi, Juniperus Deschampsia flexuosa more frequent communis nana and Salix herbacea. than in H17a, with the other associates Deschampsia flexuosa occurs sparsely listed above. Among bryophytes with the above herbs and other more Hypnum jutlandicum frequently joins occasional species. Small patches Racomitrium lanuginosum. Lichens of Racomitrium lanuginosum are are not so varied or abundant as in frequent and there is a rich and H17a, but Cladonia uncialis and extensive lichen flora including C. arbuscula remain very common. the species listed above.

107 H18 Vaccinium myrtillus – rosus, Plagiothecium undulatum, Dicranum majus and Racomitrium lanuginosum. Some Deschampsia flexuosa heath lichens occur frequently although an extensive carpet is never found. The most common species This community includes a variety of moss-rich are Cladonia arbuscula, C. impexa and C. uncialis. and grassy sub-shrub vegetation, in which This community is typical of moist but Vaccinium myrtillus is the most frequent ericoid, free-draining, base-poor to circumneutral soils with Calluna vulgaris only occasional and often over steeper slopes at moderate to high altitudes lacking in vigour. Other sub-shrubs can make a through the uplands of northern Britain. It is large- sizeable contribution to the canopy; in particular ly confined to altitudes above 400 m and can Empetrum nigrum, usually ssp. hermaphroditum, extend up to 800 m. It occurs over a wide variety is most frequent, often forming patches. of bedrocks on a variety of soil profiles which Vaccinium vitis-idaea is also common. have a superficial pH of 3.5-5.5. Typically, howev- Among vascular associates Deschampsia flexuosa er, the soils have a well-developed humic layer. and Galium saxatile are constant throughout, with This community is widespread through the Nardus stricta, Agrostis canina ssp. montana and uplands of Britain but is particular common in Potentilla erecta all very frequent. In some stands northern Scotland, where the heart of its range these species account for virtually all the occurs in the central and eastern Highlands, with herbaceous cover. The grasses Festuca ovina, Agrostis more sporadic occurrences to the north-west. capillaris and Anthoxanthum odoratum occur at At higher levels this vegetation is probably a least occasionally and increase in frequency and natural climax with the floristics and distribution abundance in some sub-communities. of the community being influenced by snow-lie, The other element, which is usually promi- but towards the sub-montane zone quite extensive nent, comprises bulky mosses. Dicranum scopari- stands of the vegetation have been biotically um, Pleurozium schreberi and Hypnum cupressi- derived as a result of woodland clearance and forme s.l. are very common throughout, Hylo- pasturing. In other places treatments such as burn- comium splendens is also conspicuous and there ing and grazing have precipitated its spread on to can be frequent Rhytidiadelphus loreus, R. squar- blanket peats.

108 Cladonia Blechnum – is infre- Festuca Calluna accinium Pleurozium and being locally V and herbaceous are usually domi- sparse, and H18c C. impexa accinium vitis-idaea. Hypnum cupressiforme V Carex bigelowii occasional. and or mixtures of this with and absent and pleurocarps rather Racomitrium lanuginosum are very frequent and can be Galium saxatile Cladonia arbuscula Lichens, however, are best repre- Lichens, however, Racomitrium lanuginosum spp. sub-community This is sometimes developed where peaty soils have been burned or on degraded blanket peats. myrtillus Empetrum nigrum nant, with sparse plants of vulgaris Calluna vulgaris C. uncialis spicant patchy. common and lichens quite conspicu- ous, abundant and Deschampsia flexuosa ovina abundant, with other grasses only occasional. quent but locally abundant. Apart from dicotyledons are uncommon. The only common pleurocarps are schreberi s.l. sented in this sub-community, particularly the species listed above. This sub-community is found through- out the range of H18. is diag- and Empetrum accinium V – Hylocomium Sub-shrubs generally strongly domi- nant with the listed herbs opposite occasional at most. is very common Blechnum spicant quite common among H18a accinium myrtillus uliginosum. Rhytidiadelphus loreus

V V. Blechnum spicant or and is occasionally co-dominant Pleurozium schreberi Cladonia arbuscula. H18 nostic. Bryophytes attain their most diverse and extensive cover here, particularly the species listed above. Lichens are generally much less obvious, the only frequent species being This sub-community is found through- out the range of H18. Deschampsia flexuosa and sometimes abundant, but grasses are not as abundant in H18b. A high frequency of Hylocomium splendens Rhytidiadelphus loreus sub-community This sub-community is generally found in and around snow-beds on acidic soils. Sub-shrubs are generally dominant with vitis-idaea Dicranum scoparium. Calluna vulgaris the sub-shrubs with frequent. Mosses forming an exten- sive ground carpet with splendens joining usually most abundant, but nigrum and in some stands with is Agrostis Luzula and , iola V , Carex pilulifera can be quite – in the canopy and/or grasses H18b and occasional Anthoxanthum odora- Festuca ovina Empetrum nigrum Ranunculus acris. Carex pilulifera also common with , and and are especially common. accinium myrtillus Alchemilla alpina sub-community This sub-community is found at lower altitudes and favours sunnier aspects with less humic and sometimes base-poor soils. Grazing often plays an important part in its development. V abundant but scarcer than in H18a. Ericoids as a whole are often co-dominant with Alchemilla alpina and/or with grasses which are best represented here. There is a variety of dicotyledonous herbs including the species listed above. Bulkier mosses can be quite frequent but not with the same abundance and variety as in H18a. Lichens are sparse. This sub-community is especially characteristic of the Breadalbane- Clova region. riviniana C. binervis Potentilla erecta Campanula rotundifolia Sub-shrubs often co-dominant with Alchemilla alpina among which capillaris tum campestris

109 H19 Vaccinium myrtillus – frequent or there may only be sparse shoots of Cladonia arbuscula heath Polytrichum alpestre and P. piliferum. Much more important are the lichens, particular- This community consists essentially of a very low ly larger fruticose species such as Cladonia arbuscu- mat, 5-10 cm high, of sub-shrubs with an abun- la and C. uncialis, both constants, and less common- dance of lichens, often marking stands with a yel- ly C. rangiferina and C. gracilis, mixtures of which lowish tinge. Lichens are more extensive and can exceed the sub-shrubs in total cover. Cetraria dominant than in the Calluna vulgaris – Cladonia islandica and Cornicularia aculeata are also very arbuscula heath (H13). Calluna vulgaris is uncom- common, often with a variety of other species. mon overall and Vaccinium myrtillus is the most This heath is typical of base-poor soils on consistent sub-shrub, being co-dominant in more moderately sheltered and snow-bound slopes at sheltered situations, although sparse in exposed high altitudes, particularly in the more continen- sites. Vaccinium vitis-idaea is less common, but tal mountains of northern Britain. The vegetation constant, and V. uliginosum scarce overall. is strongly montane, being found mainly above Empetrum nigrum, almost always ssp. hermaph- 650 m up to 1000 m or even beyond, and usually roditum, is frequent and can exceed Vaccinium stands are found in sites with some shelter so that species in its cover. there is winter protection from lying snow. It is Vascular associates are few but Carex bigelowii, characteristic of acid soils with a superficial pH of a constant, is frequent and often abundant and about 4. It has a similar range to that of H13, being may be co-dominant with the ericoids and lichens. strongly concentrated in the central and eastern The other common and constant plant is Highlands of Scotland, particularly the Grampians, Deschampsia flexuosa. Festuca ovina is also but also in the mountains of the north-west and fairly frequent together with several herbs, such as the Southern Uplands and with scattered locali- Galium saxatile, in sub-community H19a. ties in northern England. Bryophytes are generally not important and Floristic variation reflects differences in expo- Racomitrium lanuginosum is only abundant in sure and soil type, but overall the vegetation is a one sub-community. Dicranum fuscescens is quite climatic climax.

110 , are Carex are at C. bellidi- and hermaphrodi- is the only Cetraria nivalis Racomitrium ssp. Pleurozium schre- and Lichens are very Racomitrium lanugi- H19c Cladonia rangiferina spp. sub-community accinium myrtillus Calluna vulgaris. accinium vitis-idaea Ochrolechia frigida V Galium saxatile V is accompanied by pref- can and and frequent but not abundant. Cladonia C. pyxidata Dicranum scoparium , – provide the bulk of vascular Empetrum nigrum hermaphrodi- , can be moderately abundant and there is often a little Deschampsia flexuosa common grass and species like pilulifera Ptilidium ciliare. extensive, with the most common species listed above. This sub-community is widespread on granitic and quartzitic mountains. more occasional. nosum tum and tum but are often exceeded by the cover, lichen cover. their most infrequent. lanuginosum erentially common beri Empetrum nigrum hermaphroditum very common with lichens abun- dant in the mat. C. gracilis preferentially frequent and flora Empetrum nigrum Mixed mats of Galium saxatile and , , fre- her- sometimes Juncus but both can is very patchy. and occur occasionally but not in any abun- dance. Festuca ovina and mostly ssp. , Cetraria islandica H19b lichens and Cladonia arbuscula , is occasional as the , is fairly common, but , accinium myrtillus Alchemilla alpina V Kiaeria starkei Racomitrium lanuginosum. H19 Salix herbacea C. uncialis accinium vitis-idaea maphroditum abundant Empetrum nigrum Racomitrium lanuginosum sub-community The mat is dominated by various mixtures of Carex bigelowii V Salix herbacea rare moss be locally abundant. Other vascular associates are either occasional, as above, or very occasional. The lichen cover is varied; can be abundant but may patchy and mixed carpets are more usual with Cornicularia aculeata Sphaerophorus globosus. This sub-community is found both in central and north-west Scotland. Racomitrium lanuginosum quite abundant in a rather patchy lichen cover. quent in small amounts, with occa- sional trifidus. fre- is a occasional. is most Festuca Carex is moderately Carex bigelowii. is often abundant and is sometimes co- is sometimes found H19a Galium saxatile – Galium saxatile is moderately abundant. Potentilla erecta usually co-dominant among accinium vitis-idaea V accinium myrtillus accinium myrtillus Festuca ovina frequent and abundant here. Deschampsia flexuosa abundant and V sub-community V and co-dominant with Empetrum nigrum and good diagnostic species. The lichen element is prominent although not so extensive as in sub-community H19c. Cladonia arbuscula dominant with the vascular plants and C. uncialis This sub-community is more charac- teristic of the lime-rich rocks between Breadalbane and Clova, although the pH of the soil surface is still strongly acid. bigelowii the vascular plants, with ovina/vivipara. Galium saxatile quent and

111 H20 Vaccinium myrtillus – Racomitrium lanuginosum is very important, Racomitrium lanuginosum heath forming a woolly carpet, and it is found with a variety of other bulky mosses. Hypnum cupressi- This community brings together a variety of forme s.l., Hylocomium splendens, Rhytid- vegetation types in which Vaccinium myrtillus iadelphus loreus and Pleurozium schreberi are all and/or Empetrum nigrum ssp. hermaphroditum constant and can be prominent. Additionally, occur, occasionally with other sub-shrubs such as Polytrichum alpinum and Dicranum scoparium V. vitis-idaea, and are co-dominant with Racom- are found in many stands. Common hepatics are itrium lanuginosum or hypnaceous mosses. Ptilidium ciliare and Diplophyllum albicans, but Vaccinium myrtillus and E. nigrum form a low their greatest variety is found in the Bazzania – mat, usually less than 10 cm high, appearing as a Mylia sub-community. Lichens are less important, patchy mosaic of bushes among the moss carpet. but Cladonia uncialis and C. arbuscula are most At lower altitudes Juniperus communis ssp. nana frequent throughout and may be modestly and Erica cinerea can show local prominence. abundant, with C. gracilis and Cetraria islandica Among vascular associates Carex bigelowii, also common. Festuca ovina/vivipara, Deschampsia flexuosa This heath is characteristic of humic, base-poor and Galium saxatile are all constant and frequent. soils on fairly exposed slopes and summits at There are few other common herbs, although the moderate to high altitudes, in the cool oceanic grasses may include frequent Nardus stricta. mountains of north-west Scotland, extending to Huperzia selago and Potentilla erecta are frequent Skye, and scattered through the Grampians. in some stands and may be accompanied by Almost always, the bedrocks underlying this Thymus praecox, Viola riviniana and Carex heath are siliceous in character. pilulifera. Climatic differences and some modest varia- Much of the distinctive character of this tion in edaphic conditions influence the floristics, vegetation type depends on the cryptogams. but this is essentially climax vegetation.

112 , , , , ssp. Alectoria carpet, but Hypnum and Cetraria Nardus stricta accinium myr- , Polytrichum , V Racomitrium Anthoxanthum sub-community and and H20b and Cladonia leucophaea Cornicularia aculeata are usually dominant. Festuca ovina/vivipara Empetrum nigrum tend to be prominent, but and The lichen flora is a little Cladonia gracilis with abundant Anastrepta and islandica and occasional Sphaerophorus globosus nigricans. Bulky pleurocarps can be common but not abundant among the dominant Racomitrium lanuginosum the lichen carpet is richer with fre- quent Cetraria islandica Mixtures of hermaphroditum tillus lanuginosum Grasses like Deschampsia flexuosa Agrostis canina odoratum the richness of vascular plants in H20a is absent. Bryophytes are not numer- ous although community constants are all common with frequent cupressiforme s.l. alpinum. richer than usual with the species listed above present. This is the most widespread and com- mon sub-community overall. is , sometimes found but com- accinium are more V reduced in – and Galium saxatile Diplophyllum albicans orcadensis binations of these other bryophytes rare. Deschampsia flex- very common H20d and Pleurozium schreberi is preferentially common, Racomitrium lanuginosum are frequent and Festuca ovina/vivipara Racomitrium lanuginosum cover with dominance often passing to mixtures of Hylocomium splendens Rhytidiadelphus loreus. Rhytidiadelphus loreus Hylocomium splendens sub-community Although the general generally reduced in cover, vegetation features accord well with the community as a whole. vitis-idaea Carex bigelowii uosa and occasional. The moss mat is distinctive with dominance passing to the species listed above. The Atlantic hepatics found in H20c are absent. This sub-community is local through- out the range of H20. accinium vitis-idaea V and all other listed associates scarce. , , and carpet with H20 ornithopodi- Mylia taylori Plagiothecium S. – , Bazzania tricrena- , are frequent. The , Blechnum spicant frequent. H20c Diplophyllum albicans , Sphagnum capillifolium , Anastrepta orcadensis , Juncus trifidus Scapania gracilis , Anthelia julacea Mylia taylori Pleurozia purpurea oides Rich and luxuriant patchwork of bryophytes present among the Racomitrium lanuginosum Dicranum scoparium undulatum ta Bazzania tricrenata sub-community Here the general floristic features are as in H20b though and community mosses are well represent- ed but distinctively there is a range of conspicuous bryophytes, including Atlantic hepatics as listed above. Lichens are generally sparse. This sub-community is very much confined to the wettest regions and even then it is restricted to suitable cold and damp aspects. can and and Erica Carex or Thymus is the only , occasional can both be and sometimes co- nana very scarce, but Herbs characteris- Festuca ovina/ Racomitrium ssp. Thymus praecox Erica cinerea H20a , – , remain very frequent Alchemilla alpina as the typical dominant, Potentilla erecta iola riviniana frequent. Deschampsia flexuosa V , may occur with sparse shoots , accinium myrtillus Alchemilla alpina V Diplophyllum albicans Calluna vulgaris. iola riviniana accinium vitis-idaea praecox pilulifera dominant. Juniperus communis nana V Calluna vulgaris with V sub-community The sub-shrub mat is more varied than usual in the community. Empetrum nigrum hermaphroditum and lanuginosum but other pleurocarps are less frequent and common hepatic. This sub-community extends the range of H20 into the milder foothills western seaboard and Skye. and are joined preferentially by the herbs listed above. The cryptogam with flora is poor, Galium saxatile be co-dominant and more locally Juncus communis of tic of H20, such as vivipara abundant, but cinerea

113 H21 Calluna vulgaris – locus for the ‘mixed northern hepatic mat’. Vaccinium myrtillus – Sphagnum Species such as Scapania gracilis, Mylia capillifolium heath taylori and Diplophyllum albicans can be found throughout, but the Mastigophora – Herbertus This community has a mixed canopy of sub- sub-community has an additional range of Atlantic shrubs, usually 30-50 cm high, with a damp layer species, forming a unique vegetation found at high- of luxuriant bryophytes. Calluna vulgaris is usual- er altitudes in north-west Scotland where summer ly the dominant ericoid, although Vaccinium myr- temperatures are lower and rainfall higher. Lichens tillus is constant and Empetrum nigrum, almost are fairly insignificant, Cladonia impexa being the always ssp. hermaphroditum, very frequent. Erica only species occurring commonly throughout. cinerea is also frequent, but patchy. Other sub- This heath is highly characteristic of fragmen- shrubs are only occasional. tary humic soils, developed in situations with a Deschampsia flexuosa and Potentilla erecta are cool but equable climate and a consistently shady constant and very common though usually present and extremely humid atmosphere. It is almost as sparse, scattered individuals. More distinctive- wholly confined to low to moderate altitudes ly Blechnum spicant is constant and Solidago through the oceanic mountains of north-west virgaurea and Listera cordata frequent. There are Scotland and on Skye, with outliers on Orkney, in only occasional records for other vascular south-west Scotland and the Lake District. associates. It is largely restricted to steep, sunless slopes of The bryophytes form an extensive and lush car- north-west to easterly aspect, often with rock pet. Constant throughout are bulky hypnaceous outcrops and blocky talus, among which crevices mosses such as Hypnum cupressiforme s.l., provide additional shade. In some situations this Rhytidiadelphus loreus, Pleurozium schreberi and may not be a climax community but a result of Hylocomium splendens, with Plagiothecium undu- woodland clearance, but towards the upper end of latum, Dicranum scoparium and D. majus also its altitudinal limits this heath appears to form a very common. Particularly distinctive is the high natural component of vegetation patterns con- frequency and local abundance of Sphagnum trolled largely by variations in local climates and capillifolium. Racomitrium lanuginosum becomes soils. It is sometimes lightly grazed, but burning more frequent at higher altitudes. The most spec- is very damaging and recovery is probably tacular enrichment in this element comes from extremely slow. It seems certain that the extent of oceanic hepatics and this community is a major this community has been reduced by burning.

114 H21

Empetrum nigrum hermaphroditum frequent and locally Empetrum nigrum hermaphroditum local and combina- abundant among the sub-shrubs with especially rich and tions of listed cryptogams rare, but Dicranum scoparium luxuriant cryptogam carpets among which there is frequent common with frequent fronds of Pteridium aquilinum. Racomitrium lanuginosum, Mylia taylori, Scapania gracilis, Bazzania tricrenata, Pleurozia purpurea, Diplophyllum albicans, Anastrepta orcadensis, Mastigophora woodsii, Herbertus aduncus hutchinsiae, Cladonia uncialis and C. arbuscula.

H21b H21a

Mastigophora woodsii – Herbertus aduncus ssp. Calluna vulgaris – Pteridium aquilinum hutchinsiae sub-community sub-community

Calluna vulgaris is usually the most abundant sub-shrub, This sub-community occurs in sites which cannot support but the canopy is short and more mixed than in H21a. The the full range of hepatics. Calluna vulgaris is generally a bryophytes are extremely well developed. Among the moss- strong dominant in this taller and more species-poor es all the community constants occur frequently. The hepat- heath. Vaccinium myrtillus is very common with Erica ics, however, are most abundant, tingeing the vegetation cinerea and Vaccinium vitis-idaea occasional. Other vascu- with a variety of colours. They include the species listed lar plants are sparse, but distinctive is Pteridium aquil- above with other rarer Atlantic hepatics. inum with occasional Oxalis acetosella, Viola riviniana and Luzula sylvatica. Bryophytes can have fairly high This sub-community is restricted in range, being confined cover, but comprise almost entirely the community to the more shaded and humid habitats in north-west constants. Scotland. This sub-community is found throughout the range of H21.

115 H22 Vaccinium myrtillus – especially common and several other species locally abundant. A variety of other mosses and Rubus chamaemorus heath hepatics are variable in their occurrence. Lichens are typically less prominent, although Cladonia This heath has a mixed cover of sub-shrubs over a arbuscula is constant and can show modest moist cover of bryophytes similar to that abundance. of Calluna vulgaris – Vaccinium myrtillus – This heath is characteristic of wet, base-poor Sphagnum capillifolium heath (H21). However, peats at moderate to high altitudes (mainly between here the canopy is not as tall, being mostly 500 m and 800 m), where there is protection against between 10 and 30 cm high, and Calluna vulgaris extremes of dryness and winter cold by virtue of an is not invariable in its dominance (Vaccinium oceanic influence or locally prolonged snow-lie. myrtillus is dominant in the Polytrichum – Galium The profiles found beneath this community are sub-community). Empetrum nigrum ssp. her- typically poorly-developed, often consisting of maphroditum is constant, as is V. vitis-idaea just a layer of bryophyte or ericoid humus resting (although less frequent), and V. uliginosum is rare. directly on blocky talus, derived from a variety of Erica cinerea is absent. pervious bedrocks. It is almost entirely confined to The vascular associates are distinctive because, the central and north-west Highlands of Scotland. with constant Deschampsia flexuosa, there is In the former region it is typical of early snow-beds frequently a little Rubus chamaemorus and where it is mainly present as the Polytrichum – Cornus suecica. Eriophorum vaginatum can be Galium sub-community. In the north-west High- locally abundant and there are records for lands, where the climate is ameliorated by the Potentilla erecta, Melampyrum pratense, oceanic climate, this heath is generally represented Listera cordata, Juncus squarrosus and Nardus by the Plagiothecium – Anastrepta sub-community. stricta. Climatic and edaphic factors maintain this Bryophytes are always conspicuous and heath as a climax vegetation in most situations, sometimes very abundant. Dicranum scoparium although at its lowest limits it falls within the alti- and the hypnaceous mosses Pleurozium schreberi, tudinal range of historical pine forest. It is some- Hylocomium splendens and Rhytidiadelphus times affected by grazing and burning where these loreus are the most consistent and constant, treatments are applied to the surrounding heaths. although Sphagnum spp. can also have a high Burning is deleterious to the floristic richness of cover, with the constant S. capillifolium being the community.

116 H22

Carex bigelowii frequent in small amounts with a rich Carex bigelowii and cryptogams listed opposite all very and extensive patchwork of cryptograms, among which scarce, but Gallium saxatile and Blechnum spicant frequent Racomitrium lanuginosum, Plagiothecium undulatum, as scattered individuals and Polytrichum commune very Ptilidium ciliare, Anastrepta orcadensis, Barbilophozia common among usually plentiful hypnaceous mosses. floerkii, Cladonia bellidiflora, C. uncialis, C. leucophaea, C. gracilis and C. impexa are very common.

H22b H22a

Plagiothecium undulatum – Anastrepta orcadensis Polytrichum commune – Galium saxatile sub-community sub-community Vaccinium myrtillus is generally dominant in a low sub- Calluna vulgaris is often a strong dominant in a taller shrub canopy with Calluna vulgaris and/or Empetrum canopy with Empetrum nigrum ssp. hermaphroditum nigrum ssp. hermaphroditum sub-dominant. Vaccinium occasionally abundant. Vaccinium myrtillus usually has low vitis-idaea is fairly common but of low cover. Cornus sueci- cover and V. vitis-idaea occurs unevenly. Cornus suecica, ca and Rubus chamaemorus are most consistently frequent Rubus chamaemorus and Deschampsia flexuosa are all here though not abundant. Deschampsia flexuosa is rather more patchy than in H22a, though Eriophorum vaginatum is patchy and Blechnum spicant and Galium saxatile are common as scattered shoots. Carex bigelowii and Huperzia preferentially common. Hypnaceous mosses, especially selago are preferential at low frequencies. The cryptogams Hylocomium splendens and Rhytidiadelphus loreus, are are distinctive with both hypnaceous mosses and plentiful with Sphagnum capillifolium patchily abundant. Sphagnum spp. prominent together with a number of Lichens are rare apart from scattered Cladonia arbuscula. Atlantic hepatics including the species listed above. Lichens This sub-community is largely restricted to the central are also more numerous in this sub-community with the Highlands. above species present and Cladonia arbuscula constant. This sub-community occurs throughout the range of H22 and is particularly well-developed in the north-west Highlands.

117 118 119 120 The Joint Nature Conservation Committee is the forum through which the three country nature conservation agencies – the Countryside Council for Wales (CCW), English Nature (EN) and Scottish Natural Heritage (SNH) – deliver their statutory responsibilities for Great Britain as a whole and internationally. These responsibilities, known as the special functions, contribute to sustaining and enriching biological diversity, enhancing geological features and sustaining natural systems. The special functions are principally: • to advise ministers on the development of policies for, or affecting, nature conservation in Great Britain and internationally; • to provide advice and knowledge to anyone on nature conservation issues affecting Great Britain and internationally; • to establish common standards throughout Great Britain for the monitoring of nature conservation and for research into nature conservation and the analysis of the results; and • to commission or support research which the Committee deems relevant to the special functions.

This Guide is one of a new series of interpretative publications intended to support users of the National Vegetation Classification. These publications will focus on providing further guidance on practical aspects of the NVC.

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