Andrew Perry

Mires of the Long Mynd: Part 2

Andrew Perry

In this article I’ll be describing the vegetation of springs and soakaways on the Long Mynd. Springheads are numerous near the heads of valleys on the Mynd, and a distinctive flora occurs in the running water and saturated mud around them. These areas are small, sometimes only a few square metres, and unlike the flushes described in the previous article, you cannot walk through them without sinking at least ankle deep! Low, lush-green vegetation dominates with cushions of Montia fontana Blinks with Ranunculus omiophyllus Round-leaved Crowfoot, Juncus bulbosus Bulbous Rush, Myosotis secunda Creeping Forget-me-not, Ranunculus flammula Lesser Spearwort, Callitriche stagnalis Common Water-starwort, Glyceria spp. Sweet-grasses and Potamogeton polygonifolius Bog Pondweed. Frequent bryophytes here include Philonotis fontana Fountain Apple-moss, Calliergonella cuspidata Pointed Spear-moss, Brachythecium rivulare River Feather-moss and the nationally scarce Bryum weigelii Duval’s Thread-moss. The latter is more typical of mountains and the shores of highland loch shores, with the Long Mynd representing the southern extreme of its range. Such plant communities are described in the National Vegetation Classification (NVC) as M35 Ranunculus omiophyllus-Montia fontana rill. M35 is most common in the southwest of Britain, containing oceanic West European plants such as R. omiophyllus, but can also include species of montane springs (Rodwell, 1991). The spring water is usually circumneutral, averaging around pH 6 on the Long Mynd (Callaghan, 2012), and the springs are very attractive to grazing animals which bring some localised nutrient enrichment. The floristic table for M35 by Rodwell (1991) also lists Sphagnum denticulatum Cow-horn Bog-moss as a community constant, but this species is usually lacking from M35 on the Long Mynd, although S. inundatum Lesser Cow-horn Bog-moss or the nationally scarce S. platyphyllum Flat-leaved Bogmoss sometimes occur. On the Mynd, spring head vegetation can also include common grassland plants such as Lotus pedunculatus Greater Bird’s-foot Trefoil, Trifolium repens White Clover, Cardamine pratensis Cuckooflower, Arrhenatherum elatius Sweet Vernal-grass and Holcus lanatus Yorkshire Fog. Triglochin palustris Marsh Arrowgrass and Isolepis setacea Bristle Club-rush can also be found around our springs; both have a local distribution in Shropshire (Lockton and Whild, 2015). Spring heads can be found in the upper reaches of most valleys on the site, with some good examples in Ashes Hollow and Boiling Well, and M35 also occurs in small patches along the edges of streams. Downstream of the springs, small sedge or rush communities often occur where there is a constant movement of water through the

soil. Some examples, e.g. at the top of Jonathan’s Hollow, can be quite species rich and are probably best described as a form of M23 Juncus effusus/ acutiflorus-Galium palustre rush-pasture, with frequent Juncus acutiflorus Sharp-flowered Rush, Hydrocotyle vulgaris Marsh Pennywort, Ranunculus flammula, Succisa pratensis Devil’s-bit Scabious, Epilobium palustre Marsh Willowherb, Carex nigra Common Sedge, C. echinata Star Sedge, C. demissa Common Yellow-sedge and C. panicea Carnation Sedge. Another spring community recorded on the Long Mynd is M37 Palustriella commutata - Festuca rubra spring (Callaghan, 2012). This upland community is dominated by cushions of the moss Palustriella commutata Curled Hook-moss, and vascular plants can be sparse. M37 is usually found on more calcareous rocks, and presumably occurs on the Mynd where there is sufficient baseenrichment of the spring water. Another vegetation community occurring alongside streams or in wet depressions are known as soakaways and include M29 Hypericum elodes-Potamogeton polygonifolius soakaway. M29 is uncommon on the site, occurring in small quantities alongside streams or in wet depressions.

Hypericum elodes Marsh St. John’s-wort in Catbatch (Andrew Perry). Like M35, this can also be very boggy with much surface water, and both can include Potamogeton polygonifolius, Juncus bulbosus and Ranunculus flammula, but M29 usually lacks R. omiophyllus and Montia fontana. M29 soakaways can also be distinguished by the presence of Hypericum elodes Marsh St. John’s-wort in the southwest of Britain, although this species may be absent further north (Elkington et al., 2001). H. elodes is scarce and declining in Shropshire (Lockton and Whild, 2015) but can be found in some of the M29 on the Long Mynd. Other species found here are Anagallis tenella Bog Pimpernel, Juncus articulatus Jointed Rush, Juncus effusus Soft Rush, Eriophorum angustifolium Common Cottongrass, Hydrocotyle vulgaris, Narthecium ossifragum Bog Asphodel, Drosera rotundifolia Round-leaved Sundew, Galium palustre Marsh Bedstraw, Agrostis canina Velvet Bent and the sedges described earlier. Sphagnum denticulatum is a community constant, sometimes with S. palustre Blunt-leaved Bog-moss, S. fallax Flat-topped Bog-moss and Polytrichum commune Common Haircap also present. This list of acidic associates might sound like the M6 Carex echinataSphagnum fallax/denticulatum mire discussed in Part 1, but M29 can be distinguished from M6 by the floating mats of Potamogeton polygonifolius

Triglochin palustris Marsh Arrowgrass (Andrew Perry).

and Hypericum elodes (when present). Catbatch and the flush on Nover’s Hill is a good place to see many of the species described here, along with some rare liverworts including the legally protected Jamesoniella undulifolia Marsh Flapwort. Communities notable by their absence are the wet heaths and blanket mires (e.g. M15 – M20). It is unknown whether these vegetation types once occurred here, although quadrats resembling M19 Calluna vulgaris – Eriophorum vaginatum blanket mire have been recorded on deep peat at Wildmoor (Iain Diack pers. comm., 2021). The Long Mynd has a long history of human occupation, and if blanket bog did once occur here, it is likely that historic burning, heavy grazing and potentially peat cutting led to its demise long ago. Current management of the Long Mynd is now focussed on habitat conservation and restoration, and graziers of the Common have been in agrienvironment schemes since the late 1990’s which has reduced grazing pressure on the vegetation. Heathland management by the National Trust is also targeted to avoid cutting, burning or vehicle damage to wet areas. Mire vegetation (including springs heads and soakaways) is monitored at a number of sample plots where attributes such as species composition, grazing impacts, wetness, vegetation structure and damage are assessed. Fixed point photography is also employed to track change over time. Whilst there is still localised grazing damage at some plots, overall there has been a positive trend in increased flowering levels. A future monitoring ambition is to try and quantify the increase of Sphagnum that has been observed at Wildmoor and in other mires on site. Acknowledgements: many thanks to Peter and Jane Howsam for sharing their photographs, and to Mags Cousins for proof reading the article.

References:

Callaghan, D. (2012) Bryophytes and vegetation communities of springs and flushes on The Long Mynd (Shropshire). An unpublished report by EcoStudy to Natural England Elkington, T., Dayton, N., Jackson, D.L. & Strachan, I.M. (2002) National Vegetation Classification field guide to mires and heaths. JNCC, Peterborough, ISBN 1 86107 526 X Lockton, A. & Whild, S (2015) The Flora & Vegetation of Shropshire. Shropshire Botanical Society, Shrewsbury. ISBN 978-0-9530937-2-4. Rodwell, J.S. (ed.) (1991) British Plant Communities. Volume 2. Mires and heaths. Cambridge University Press.