The background to the work

It is a tribute to the insight of our early ecologists that we can still return with profit to Types of British Vegetation which Tansley (1911) edited for the British Vegetation Committee as the first coordinated attempt to recognise and describe different kinds of plant community in this country. The contributors there wrote practically all they knew and a good deal that they guessed, as Tansley himself put it, but they were, on their own admission, far from comprehensive in their coverage. It was to provide this greater breadth, and much more detailed description of the structure and development of plant communities, that Tansley (1939) drew together the wealth of subsequent work in The British Islands and their Vegetation, and there must be few ecologists of the generations following who have not been inspired and challenged by the vision of this magisterial book.

Yet, partly because of its greater scope and the uneven understanding of different kinds of vegetation at the time, this is a less systematic work than Types in some respects: its narrative thread of explication is authoritative and engaging, but it lacks the light-handed framework of classification which made the earlier volume so very attractive, and within which the plant communities might be related one to another, and to the environmental variables which influence their composition and distribution.

Synonymy

Braunton Damp Pasture Willis et al. 1959; Salix repens-Holcus lanatus nodum Jones 1992; Festuca rubra-Brachythecium rutabulum nodum Jones 1992.

Constant species

Carex flacca, Festuca rubra, Holcus lanatus, Lotus corniculatus, Salix repens.

Physiognomy

In the Salix repens-Holcus lanatus dune-slack community, Salix repens is generally dominant in a bushy canopy that can be several decimetres tall. Its most frequent associates are Holcus lanatus and Festuca rubra, the abundance of which often give a rank grassy aspect to the sward among the willow. Agrostis stolonifera and Poa pratensis are at least occasional throughout but also common among the associates are Carex flacca and a range of dicotyledonous herbs including Lotus corniculatus, Euphrasia officinalis agg., Hieracium pilosella, Senecio jacobaea, Prunella vulgaris, Leontodon autumnalis and Epipactis palustris. Ononis repens is also quite frequent overall but rather patchy in its representation among the various sub-communities and not consistently abundant.

Bryophytes are not typically a prominent element in the vegetation but Bryum pseudotriquetrum is occasional and there is sometimes patchily prominent Calliergon cuspidatum and Campylium stellatum.

Sub-communities

Ononis repens sub-community. Ononis repens is at its most frequent and abundant here with preferentially common Carex arenaria, Hypochoeris radicata and Galium verum. Young shrubs and trees are quite frequent too, with bushes or saplings of Salix caprea, Betula pubescens and Quercus robur.

Rubus caesius sub-community. O. repens and saplings of the above woody species remain occasional to sparse here but Rubus caesius is constant with occasional Potent illa anserina.

Constant species

Agrostis stolonifera, Myosotis arvensis, Poa annua, Poa trivialis, Polygonum aviculare.

Physiognomy

Poa annua and P. trivialis are constant in the Poa-Myosotis arvensis community and the former in particular can have high cover. Agrostis stolonifera and Elymus repens are also very frequent overall and, among these grasses, are scattered plants of Polygonum aviculare and Myosotis arvensis. Other common associates include Stellaria media, Chamomilla suaveolens, Ranunculus repens, Veronica persica and Anagallis arvensis. More occasional are Lamium purpureum, Bilderdykia convolvolus and Lolium perenne.

Sub-communities

Typical sub-community. Polygonum persicaria and Sonchus asper are rather more frequent here with occasional Urtica dioica, Dactylis glomerata, Lolium multiflorum, Chenopodium album and Atriplex patula.

Dicranella staphylina-Bryum sub-community. Among vascular plants, Aphanes arvensis and Veronica arvensis become frequent in this sub-community with occasional Lapsana communis, Viola arvensis, Heracleum sphondylium and Trifolium repens. However, the more striking feature over the surface of the soil is the variety and abundance of diminutive acrocarpous mosses. Dicranella staphylina, Phascum cuspidatum, various Bryum spp. (including B. rubens, B. erythrocarpum, B. microerythrocarpum, B. violaceum and B. klinggraeffii) are frequent with occasional Pottia truncata, P. intermedia, Barbula convoluta and B. unguiculata.

Habitat

The Poa-Myosotis community is characteristic of trampled and dunged areas within damp leys, pastures and recreational swards. In such situations, P. annua germinates very readily where seeding has been poor or where trampling creates gaps. Its seed remains viable in the dung of cows and horses and can germinate in cattle dung (Hutchinson 1979).

Adam (1976) recognised a number of vegetation types of the low marsh in which Puccinellia maritima was codominant with annual Salicornia species and/or Suaeda maritima during the growing season but which during the winter took on the appearance of very open Puccinellia maritima swards. Such transitional vegetation can be regarded as one extreme of variation within the Puccinellietum maritimae but, particularly in detailed studies of individual marshes, separate recognition might be appropriate. The description below refers to stands in which all three taxa are present.

Synonymy

Puccinellietum maritimae (Warming 1906), W. Christiansen 1927 auct. p.p.; Puccinellia-Salicornia-Suaeda nodum Adam 1976; Suaedetum maritimae auct. p.p.

Constant species

Puccinellia maritima, annual Salicornia spp., Suaeda maritima.

Rare species

Arthrocnemum perenne.

Physiognomy

Stands of the community are invariably species-poor and always dominated by complementary proportions of the three constants which during the growing season form a fairly low sward of rather variable total cover. Rayed Aster tripolium and A. tripolium var. discoideus are quite frequent though never abundant. There is sometimes an algal mat which can cover up to 50% of the substrate surface.

Habitat

At its lower limit the number of tides flooding the community is probably similar to that experienced by the lower part of the Puccinellietum maritimae. Soils vary from firm clays to coarse sands with a pH range of 7.0–8.0 and high levels of free calcium carbonate.

Synonymy

Asplenium trichomanes-Fissidens cristatus Association, Limestone facies p.p. and Montane facies Birks 1973.

Constant species

Asplenium ruta-muraria, Asplenium trichomanes, Asplenium viride, Cystopteris fragilis, Festuca ovina, Ctenidium molluscum, Fissidens cristatus, Tortella tortuosa.

Rare species

Polystichum lonchitis, Woodsia alpina.

Physiognomy

The Asplenio-Cystopteridetum comprises open vegetation, often fragmentarily disposed in rock crevices on narrow ledges and among screes, in which a variety of ferns can assume prominence. Asplenium trichomanes (sometimes, according to Page (1982), ssp. trichomanes here, rather than the more widespread ssp. quadrivalens) remains quite common in this community but it peters out at higher altitudes. Even more so is this true of A. ruta-muraria, which among available samples is constant, but across the range of this vegetation as a whole is largely confined to stands outside the Scottish Highlands. The most characteristic spleenwort, then, is A. viride, particularly in the mountains of Scotland and northern England. This fern can occur in considerable abundance here, its rosettes of rather delicate pale green fronds, typically all turned towards the light, persisting into the winter and then dying down (Page 1982).

The other distinctive constant among the ferns is Cystopteris fragilis, a gregarious species, the fragile little fronds of which emerge rapidly in spring but which are cut back suddenly by the first frosts of autumn (Page 1988).

Constant species

Poa annua, Sagina procumbens.

Physiognomy

The Sagino-Bryetum is a species-poor but highly distinctive community in which cushions of Bryum argenteum and small scattered individuals of Poa annua and Sagina procumbens form the most consistent features, often disposed in striking patterns between cobble stones and pavement cracks. No other species are frequent throughout but Capsella bursa-pastoris, Plantago major and Agrostis stolonifera are occasional and Stellaria media and Medicago lupulina can sometimes be seen. Mosses like Bryum bicolor and Schistidium apocarpum occur as scarce associates of B. argenteum.

Sub-communities

Typical sub-community. There are no additional consistent features here but Arenaria serpyllifolia, Juncus bufonius and Polygonum aviculare occur occasionally with Ceratodon purpureus. Sagina apetala and S. subulata can sometimes be found among the S. procumbens.

Lolium perenne-Chamomilla suaveolens sub-community.

The vegetation in this sub-community is richer and more extensive in cover than above, with L. perenne and C. suaveolens both constant, Plantago major and Agrostis stolonifera frequent, Dactylis glomerata, P. major and Agrostis stolonifera frequent,and Ranunculus repens occasional.

Habitat

The Sagino-Bryetum is a very widespread community of crevices between cobble stones and paving slabs in streets, on pavements and in courtyards in urban and suburban areas and around farm and country dwellings, where there is trampling by pedestrians or light vehicle traffic.

Synonymy

Calliergon cuspidatum-Salix repens noda Jones 1992.

Constant species

Hydrocotyle vulgaris, Mentha aquatica, Salix repens, Calliergon cuspidatum.

Physiognomy

The Salix repens-Calliergon cuspidatum dune-slack community shares, with the Salix-Campylium vegetation, the high frequency of Salix repens, Hydrocotyle vulgaris, Mentha aquatica and Calliergon cuspidatum but the other vascular constants of that assemblage, Carex flacca, Agrostis stolonifera, Equisetum variegatum and Epipactis palustris, are of more restricted occurrence here and Campylium stellatum is extremely scarce.

Also, with more frequent records throughout for Galium palustre, Epilobium palustre, Equisetum palustre and Lotus uliginosus, the overall stamp of the vegetation tends to be like a poor fen rather than a rich fen. Also occasional in the community are Festuca rubra and Poa pratensis with local enrichment from tall herbs such as Iris pseudacorus, Filipendula ulmaria and Phragmites australis.

Apart from Calliergon cuspidatum, which is usually extremely abundant in a thick carpet, there are no frequent bryophytes and the striking contingent of calcicolous thalloid liverworts characteristic of some kinds of Salix-Campylium dune-slack is never present.

Sub-communities

Carex nigra sub-community: Calliergon cuspidatum-Salix repens noda, species-poor sub-type Jones 1992. Both Rubus caesius and Galium palustre are constant here but more strongly preferential are Carex nigra and Scutellaria galericulata with occasional Lysimachia vulgaris and Equisetum fluvitile.

Synonymy

Festucetum littoralis artemisietosum Ghestem 1972; includes Halimionetum portulacoidis, terminal phase with Artemisia maritima Beeftink 1962.

Constant species

Artemisia maritima, Festuca rubra, Halimione portulacoides, Plantago maritima.

Rare species

Limonium binervosum, L. humile, Suaeda vera.

Physiognomy

This is a species-poor community of somewhat variable physiognomy. Stands are generally small and fragmentary but they range from rank grassy patches dominated by Festuca rubra with prominent Artemisia maritima to open bushy vegetation with A. maritima over low Halimione portulacoides. There is usually a little Plantago maritima; Limonium cf. vulgare and Puccinellia maritima are also frequent.

Habitat

The Artemisietum maritimae is an upper-marsh community occurring on a variety of substrates, though often in association with tidal litter and inwashed shell fragments. Its most usual habitat is on creek levees where it forms small patches on the usually heavy clay soils which frequently show organic enrichment in the upper part of the profile. It is also found on ridges and mounds on the upper marsh and sometimes forms a fringe along the foot of sea walls or around stands of Atriplici-Elymetum pycnanthi. Where such zones occur at the marsh/dune interface the substrate is often a coarse sand.

Most occurrences are on ungrazed marshes but this may be a reflection of the predominantly south-eastern distribution of the association.

Synonymy

Festuca rubra community McLean 1935; Festucetum rubrae Gillham 1953; Armerietum Goodman & Gillham 1954, McVean 1961; Sileno maritimae-Festucetum pruinosae R. Tx. 1963 p.p., Armerieto maritimae-Daucetum gummiferi Géhu 1964 p.p., Festuco-Armerietum rupestris Malloch 1971.

Constant species

Festuca rubra, Armeria maritima.

Rare species

Asparagus officinalis ssp. prostratus, Astragalus danicus, Brassica oleracea, Carpobrotus edulis, Parapholis incurva, Scilla verna, Senecio integrifolius spp. maritimus, Silene nutans, Trifolium occidentale.

Physiognomy

The Festuca rubra-Armeria maritima community is a grassland with a generally closed sward, usually dominated by F. rubra which often forms a thick mattress. A. maritima may be abundant as scattered bulky cushions but it is not usually a dominant species. Frequent throughout the community are Agrostis stolonifera, Plantago maritima, Daucus carota ssp. gummifer and Silene vulgar is ssp. maritima. Bryophytes are generally sparse.

Sub-communities

Typical sub-community: Festuca rubra community McLean 1935; Coastal Armerietum Goodman & Gillham 1954 p.p.; Hirta mixed grassland p.p. & Rona Armerietum McVean 1961; Festuco-Armerietum rupestris, typical sub-association Malloch 1971. In this rather species-poor sub-community, F. rubra is over whelmingly dominant as a mattress which may attain a thickness of 40 cm. There are scattered cushions of Armeria maritima but Agrostis stolonifera is the only other species that is at all frequent. No species is preferential here but the prostrate maritime form of Asparagus officinalis is a notable rarity. Bryophytes are rarely able to find a place in the thick turf.

Constant species

Capsella bursa-pastoris, Chamomilla suaveolens, Lolium perenne, Poa annua, Polygonum aviculare.

Physiognomy

The Polygonum aviculare-Chamomilla suaveolens community comprises open swards characterised in late spring and summer by mixtures of Polygonum aviculare, Chamomilla suaveolens, Capsella bursa-pastoris, Poa annua and young, scattered plants of Lolium perenne. Matricaria perforata and Chenopodium album are occasional to frequent but they do not dominate and typically other associates are relatively few in number and not abundant. Smaller herbs, such as Urtica urens, Veronica persica, Anagallis arvensis, Lamium purpureum, Plantago lanceolata and Medicago lupulina, or grasses like Elymus repens, Dactylis glomerata and Agrostis stolonifera are commonest among these companions with just very occasional taller herbs such as Rumex obtusifolius, R. crispus and Artemisia vulgaris. Bryophytes are absent or very sparse.

Sub-communities

Sisymbrium officinale-Polygonum arenastrum sub-community. Polygonum arenastrum is a frequent preferential here, forming denser prostrate mats among the more branched and somewhat ascending P. aviculare, and Bilderdykia convolvulus also occurs occasionally, its long flexuous stems trailing over the ground and other low herbs. Sisymbrium officinale is common, too, with Sinapis arvensis, Stellaria media and Senecio vulgaris occasional.

Plantago major sub-community. Scattered plants of Plantago major and, more occasionally, Coronopus squamatus are characteristic here, their rosettes often flattened by trampling.

Habitat

The Polygonum-Chamomilla community is an ephemeral vegetation type of disturbed and moderately trampled loamy and sandy soils throughout the lowlands of Britain.

Constant species

Ammophila arenaria, Arenaria serpyllifolia, Carex arenaria, Festuca rubra, Phleum arenarium.

Rare species

Mibora minima, Vulpia membranacea.

Physiognomy

The Tortulo-Phleetum comprises generally open assemblages of ephemerals which make a brief appearance in the dampness of spring and early summer among gaps in a cover of perennial grasses and dicotyledonous herbs of semi-fixed to fixed dunes.

The most distinctive species of the community are the annual grass Phleum arenarium with Arenaria serpyllifola, Cerastium diffusum ssp. diffusum, Aira praecox and Viola tricolor ssp. curtisii and the moss Tortula ruralis ssp. ruraliformis. Ammophila arenaria, Festuca rubra and Carex arenaria are consistently represented in the grassland matrix in which this vegetation makes its appearance, together with Ononis repens, Lotus corniculatus, Senecio jacobaea and, more occasionally, Poa pratensis.

Light-demanding mat plants like Thymus praecox and Sedum acre figure quite commonly and there are occasional records for Cerastium semidecandrum, Desmazeria marina, Euphorbia paralias, Logfia minima, Erophila verna, Trifolium dubium, T. campestre, Erodium cicutarium, Geranium molle and Centaurium erythraea. This community also provides a locus for the nationally rare Mibora minima and Vulpia membranacea.

In addition to T. ruralis ssp. ruraliformis, Hypnum cupressiforme is frequent, Homalothecicum lutescens, Brachythecium albicans and Tortella flavovirens occasional. Peltigera canina can also occur with some local abundance.

Habitat

The Tortulo-Phleetum is a community that capitalises on the appearance of gaps with essentially stable sand that develop where semi-fixed and fixed dune swards are opened up by drought or locally disturbed, often by rabbits or modest anthropogenic activity.

The sampling of maritime cliff vegetation

Apart from along the eastern shores of England, from Flamborough Head south to the Thames estuary, steep rocky cliffs figure prominently around much of our coastline, splashed by spray to varying degrees, home to colonial sea-birds and often providing grazing for coastal farms. Yet, until relatively recently, the distinctive plant communities they support, often disposed in striking zonations related to maritime influence, the geology and soils and the influence of stock and wild herbivores, had attracted little attention, at least on a large scale. Thus, they have usually figured only in local studies, often as part of descriptions of both coastal and inland vegetation of particular sites (e.g. Petch 1933, Poore & Robertson 1949, Goodman & Gillham 1954, Gillham 1953, McVean 1961 a, Coombe 1961, Birks 1973) or, when surveyed more widely, have been described in relation to broadly-defined habitat groups (Goldsmith 1975).

We were therefore especially fortunate in this project to have the benefit of a detailed phytosociological study of sea-cliff vegetation from all around the coast of Britain carried out by Andrew Malloch of Lancaster University and building on his earlier survey of the Lizard and other parts of Cornwall (Malloch 1970, 1971, 1972). As with the general approach we adopted for this project, Malloch had located samples only on the basis of floristic and structural homogeneity of the vegetation, had used an identical range of quadrat sizes and had recorded species composition using the Domin scale of cover/abundance.

Synonymy

Bird cliff vegetation Petch 1933; Zooplethismic vegetation Poore & Robertson 1949; Cochlearietum Goodman & Gillham 1954 p.p.; Herring gull colony vegetation Sobey & Kenworthy 1979 p.p.

Constant species

Stellaria media.

Physiognomy

The Stellaria-Rumex community has a scruffy but generally closed cover of S. media with some Festuca rubra, Agrostis stolonifera and Holcus lanatus (each of which may be abundant) and a little R. acetosa and Armeria maritima. There is a variety of low frequency occasionals of maritime and inland grasslands and of disturbed habitats. Cochlearia officinalis may be much more abundant early in spring than later.

Habitat

The community is always associated with disturbance and manuring by colonial sea-birds. On St Kilda, it is particularly frequent around the nest burrows of puffin (Fratercula arctica) where there is considerable excavation of soil.

Zonation and succession

As with the Atriplici-Betetum community, this vegetation forms a mosaic with surrounding maritime crevice communities and grasslands and its spatial and temporal relationships with these are likely to be governed by the intensity of sea-bird activity and the high maritime influence.

Distribution

The community has been recorded from scattered sites from Pembrokeshire round to the Firth of Forth.

Affinities

Among the apparently rather variable assemblages of species able to take advantage of the seasonal enrichment of soils exposed to high maritime influence, this is distinct from the latter in the replacement of B. vulgaris ssp. maritima and A. prostrata by S. media and R. acetosa.

Synonymy

Juncetum maritimi auct. angl. p.p.; Triglochin-Juncus maritimus nodum Adam 1976.

Constant species

Juncus maritimus, Plantago maritima, Triglochin maritima.

Physiognomy

Tall tussocks of Juncus maritimus are always overwhelmingly dominant in this association and the associates are rather variable. However, Triglochin maritima and Plantago maritima are constant in usually small amounts in the understorey and various Puccinellion species, such as Puccinellia maritima, rayed Aster tripolium, Armeria maritima and Glaux maritima, occur frequently throughout. The association differs from the Juncus maritimus salt-marsh in the relative infrequency of Agrostis stolonifera, Festuca rubra and Juncus gerardii. Commonly the bases of the J. maritimus shoots support a variety of epiphytic algae, notably Bostrychia scorpioides and Catenella repens, and there may be an extensive algal mat, locally rich in dwarf free-living fucoids, on the substrate surface. Stands are often based upon discrete and sometimes large clones of J. maritimus but may also form a distinct zone within the marsh.

Sub-communities

Adam (1977) suggested that there are three centres of variation within the association around which sub-communities might be erected: stands which are very speciespoor, sometimes pure J. maritimus in vigorous, tall and dense patches; stands in which Halimione portulacoides and Limonium cf. vulgare are conspicuous and fairly rich stands lacking these two species.

Habitat

J. maritimus is tolerant of a wide range of salinities and soil moisture conditions (Ranwell et al. 1964, Gillham 1957b) and the association occurs at all levels on saltmarshes and on a variety of substrates.

Constant species

Agrostis stolonifera, Carex nigra, Potentilla anserina, Calliergon cuspidatum.

Physiognomy

The Potentilla anserina-Carex nigra dune-slack community comprises generally closed swards up to a decimetre or so high dominated by mixtures of grasses, sedges and rosette or mat-forming herbs. Especially distinctive is the combination of Agrostis stolonifera and Carex nigra with Potentilla anserina, each of these sometimes present in abundance and the last particularly striking when dominating in a ground carpet. Festuca rubra and Holcus lanatus are also very frequent in certain of the sub-communities and there is occasionally some Juncus articulatus. Salix repens is typically of limited occurrence here, though it is frequent and locally abundant in one type of Potentilla-Carex slack.

The other most frequent vascular associates overall are Ranunculus repens, Trifolium repens, Cardamine pratensis, Equisetum palustre and Euphrasia officinalis agg. Tall herbs like Iris pseudacorus, Angelica sylvestris and Filipendula ulmaria can give a locally distinctive stamp to the vegetation while species such as Elymus repens, Triglochin maritima and Carex disticha may lend a hint of the upper salt-marsh.

The only bryophyte which is at all frequent in the community is Calliergon cuspidatum and it can be locally abundant. Other species like Plagiomnium rostratum, Brachythecium rutabulum and Eurhynchium praelongum occur very sparsely.

Sub-communities

Festuca-rubra-Ranunculus repens sub-community. In this grassy kind of Potentilla-Carex vegetation, Festuca rubra is very frequent and of quite high cover with common records too for Ranunculus repens, Bellis perennis and Trifolium repens.