View source for OR/14/043 Definition of petrifying springs with tufa formation (Cratoneurion)

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The Interpretation Manual of European Union Habitats (European Commission, 2013<ref name="European Commission 2013">EUROPEAN COMMISSION, 2013. Interpretation Manuel of European Union Habitats EUR28. European Commission DG Environment Nature ENV B.3.</ref>) defines the Annex 1 habitat H7220 Petrifying springs with tufa formation (''Cratoneurion'') as:

* Hard water springs with active formation of tufa. These formations are found in such diverse environments as forests or open countryside. They are generally small (point or linear formations) and dominated by bryophytes (''Cratoneurion commutati'');

Lists the following associated plant species:

* Flowering plants: ''Arabis soyeri, Pinguicula vulgaris, Saxifraga aizoides; Cochlearia pyrenaica ''(in sites with heavy metals); ''Carex appropinquata, Epilobium davuricum, Juncus triglumis ''(in the Boreal region). Mosses: ''Catoscopium nigritum, ''Palustriella''commutata, ''Palustriella''falcata'', ''Cratoneuron filicinum, Eucladium verticillatum, Hymenostylium recurvirostrum ''and ''Hamatocaulis vernicosus, Philonotis calcarea, Scorpidium revolvens, S. cossonii, ''Palustriella'' decipiens, Bryum pseudotriquetum ''(in the Boreal region); and

* confirms that this vegetation type corresponds (in the UK) to the UK National Vegetation Classification (NVC) types ‘M37 ''Cratoneuron commutatum-Festuca rubra ''spring community’ and ‘M38 ''Cratoneuron commutatum-Carex nigra ''spring community’ as described by Rodwell (1998)<ref name="Rodwell 1998">RODWELL, J S. 1998. British plant communities volume 2&nbsp;—&nbsp;Mires & Heaths. Cambridge University Press.</ref>.

For the purposes of this report, the pleurocarpous moss ''Cratoneuron commutatum ''comprises the two species ''Palustriella commutata'' (Hedw.) Ochya, J.Hattori Bot., 1989 and ''Palustriella falcata'' (Brid.) Hedenas, Bryophyte. Biblioth., 1992 (as described by Smith, 2004<ref name="Smith 2004">SMITH, A J E. 2004. The moss flora of Britain and Ireland second edition. Cambridge University Press.</ref>). Together these two species will often be referred to as  ''Palustriella'' species or as ''Palustriella'' dominated vegetation. The ecology of these two species has been described by Hedenäs and Kooijman (2004)<ref name="Hedenäs 2004">HEDENÄS, L, and KOOIJMAN, A. 2004. Habitat differentation within Palustriella. LINDBERGIA 29: 40–50. LUND 2004.</ref>.

Both M37 and M38 can also generally be considered analogous with the ''Cratoneurion commutati community'', Koch 1928, a community recorded by a number of ecologists in EU member states and typically described as ‘calcareous spring communities commonly dominated by mosses’.

As the European Commission has defined the Annex I habitat ''H7220 Petrifying springs with tufa formation (Cratoneurion) ''as'' ‘''springs with active formation of tufa’, the classification of sites in Wales is more complex than for some other Annex 1 habitats as it requires both an assessment or characterisation of both the vegetation structure (NVC) and hydrogeology (determining active formation of tufa).

JNCC (2001) provide an interpretation and summary of the floristic details of the M37 ''Cratoneuron commutatum-Festuca rubra ''and M38 ''Cratoneuron commutatum-Carex nigra ''spring communities and these can be summarised as follows:

M37&nbsp;—&nbsp;Springs overwhelmingly dominated by  ''Palustriella'' species with ''Philonotis fontana ''rare to occasional. ''Sphagnum ''species absent or occurring rarely at the margins. Small sedges are scarce and the diversity of vascular plants quite poor, but usually including ''Cardamine pratensis'', ''Festuca rubra ''and ''Agrostis stolonifera.''

M38&nbsp;—&nbsp;Springs dominated by  ''Palustriella'' species that are species rich, have frequent although sparce ''Carex ''spp. (especially ''C. nigra'', ''C. panicea ''and ''C. demissa). Sphagnum ''species absent or occurring rarely at the margins. Diverse herbs including ''Cardamine pratensis'', ''Scorzoneroides autumnalis'', ''Trifolium repens ''and ''Polygonum viviparum. Philonotis fontana ''can be frequent in the moss carpet.

JNCC (2001) highlight that springs dominated by  ''Palustriella'' and ''Cratoneuron filicinum ''also occur widely, but locally, in the British lowlands, and further sampling of these is needed.

Invertebrate surveys of calcareous (although not all tufa depositing) seepages (e.g. Goodfrey, 2009<ref name="Goodfrey 2009">GODFREY, A. 2009. Invertebrate survey of calcareous seepages in South Wales. Report to the Countryside Council for Wales.</ref>) show that these sites have a potential to provide habitats for UK BAP species, ''Vertigo geyeri ''(at Craig y Cilau&nbsp;—&nbsp;Waun Ddu) and ''Lipsothrix nervosa''.
==References==
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[[Category:OR/14/043 Survey, characterisation and condition assessment of Palustriella dominated springs 'H7220 Petrifying springs with tufa formation (Cratoneurion)' in Wales | 06]]