Spring meeting 1996: Dolgellau, Gwynedd

HomeEventsSpring meeting 1996: Dolgellau, Gwynedd

10 April 1996 - 17 April 1996

Meeting report

Dolgellau was chosen as a meeting venue during the Society’s centenary year as it was here in 1922 that members of the two sections of the Moss Exchange Club agreed to unite and form the British Bryological Society. The groundwork leading to the union had been prepared by Miss Eleonora Armitage on behalf of Section I (the ‘experts’) and by Mr Daniel A. Jones on behalf of Section II (the ‘beginners’) for ‘the momentous event of 1922’ (Armitage, 1944). In the event, some twelve members gathered on two occasions at the Grammar School in Dolgellau during a meeting in early August 1922. They resolved that the new BBS should come into being on 1 January 1923, with H.N. Dixon elected as President and D.A. Jones nominated as Secretary. A proposal to admit foreign members was carried unanimously. The annual subscription was set at five shillings.

Since 1922 the Society has grown and flourished (Richards, 1983), and the involvement of over 50 participants during the 1996 spring meeting, based at the Royal Ship Hotel in Dolgellau, is a testament of its continuing good health. Numbers joining the excursions varied from day to day, and were highest during the middle part of the meeting. Four honorary members of the Society, Dr M.C.F. Proctor, Dr A.J.E. Smith, Dr E.V. Watson and Dr H.L.K. Whitehouse, were present for all or part of the meeting. Most participants were from the British mainland, and it was also a pleasure to welcome Alain Vanderpoorten from Belgium.

All excursions during the main part of the meeting were in Merioneth (VC 48) where the bryophyte flora is extremely well recorded, mainly due to the work of two local experts (see Richards, 1979; Hill, 1988). D.A. Jones (1861-1936) of Harlech found many species new to Merioneth and north Wales, and bryological exploration has been continued more recently by Peter Benoit based in Barmouth. Peter was able to join the meeting for several excursions, and his detailed knowledge of the sites enabled us to see various interesting species which may otherwise have been overlooked.

Thursday 11 April

Arthog Bog (SH 6314)

In the morning we visited Arthog Bog which is a small and rather degraded raised bog on the south side of the Mawddach estuary. The mire surface has been modified by drainage, burning and peat extraction, but the locality is a Site of Special Scientific Interest, and management is being developed to restore more favourable bog conditions in co-operation with the owners. Despite the adverse human impact, there are several rare vascular plant species on the bog, including Hypericum undulatum which was noted by a drainage channel. It is less well known for its bryophytes, although there is a small population of Pallavicinia lyellii and Peter Benoit unearthed scattered thalli among litter around the base of Molinia tussocks in one part of the site. Several common bog Sphagnum spp. were examined, together with a variety of associated hepatics, including Cephalozia lunulifolia, Odontoschisma denudatum, O. sphagni, Mylia anomala and Riccardia latifrons. Splachnum ampullaceum was noted on decaying cow dung. Unfortunately we did not re-find Cephalozia leucantha, previously recorded here at one of its few Welsh localities.

Arthog Ravine (SH 6414)

The afternoon’s excursion was to a nearby wooded ravine which is also a SSSI. The ravine is north-facing, and has a moderate Atlantic flora; substrata are mostly acidic but there are also base-rich outcrops and boulders, with overall a fairly rich bryophyte assemblage. The water level in the main stream was unusually low, so that rocks in and by the water course were relatively accessible. We were thus able to observe, at close quarters, the exceptional abundance of Jubula hutchinsiae in the Arthog ravine; rather than hiding under dripping rock overhangs, as at many of its north Wales localities, Jubula here forms large patches on relatively exposed rock surfaces and is locally frequent in a long section of the ravine. Alan Hale turned up a small quantity of Adelanthus decipiens, and Roy Perry found Lepidozia pearsonii. Other taxa recorded included Anastrepta orcadensis, Fissidens pusillus, Grimmia hartmanii and Hygrohypnum eugyrium. The ferns Dryopteris aemula and Hymenophyllum tunbrigense were also observed.

Friday 12 April

Coed y Rhygen National Nature Reserve (SH 6836)

A much larger group assembled at Coed y Rhygen where we were greeted by the NNR warden, Doug Oliver. The reserve is a rocky north-facing oakwood on the west side of Llyn Trawsfynydd reservoir. It has one of the most impressive Atlantic woodland bryofloras in southern Britain, yet this was not appreciated until 1964 when it was visited by Derek Ratcliffe. Not only is there a long list of oceanic taxa, including several rarities, but certain species such as Adelanthus decipiens, Bazzania trilobata, Lepidozia cupressina and Plagiochila punctata grow luxuriantly and in considerable abundance. One of the advantages of visiting Coed y Rhygen on a wet day, as we did, is that members of the Atlantic community appear at their best: fully turgid and relishing the mild and moist conditions. A good species list was compiled, including Dicranodontium denudatum, Dicranum fuscescens, D. scottianum, Hylocomium umbratum, Jamesoniella autumnalis, Plagiochila killarniensis and Plagiothecium laetum. Weatherwise, it was not a good day to search for very small plants, although Peter Benoit located a little Sematophyllum demissum on sheltered rocks and Marcus Yeo found patches of Leptoscyphus cuneifolius on an oak tree. The latter is here at one of its two known sites in Wales, as is Plagiochila atlantica, several good patches of which were found by Peter Martin on steep rock faces in one part of the woodland after much searching by various members of the party.

On our way back to Dolgellau, some of the group visited a flush complex on a hillside to the east of Pont y Grible, south of Trawsfynydd, at SH 7030. Various people had expressed a wish to see Sphagnum imbricatum ssp. affine and Peter Benoit was able to relocate several patches growing in a wet acid flush by the roadside. Peter Martin recorded S. platyphyllum by the side of a ditch.

When the organisers returned Peter Benoit home at the end of the day he kindly showed us two Barmouth specialities, Campylopus polytrichoides and Riccia nigrella. The Riccia has persisted in Barmouth since it was first recorded, new to Britain, by J. Ralfs in 1843.

Saturday 13 April

Morfa Dyffryn National Nature Reserve (SH 5525)

Morfa Dyffryn and Morfa Harlech are a pair of extensive sand dune systems situated near Harlech. Both are NNRs and Morfa Dyffryn, which we visited, is the more southerly of the two. There is a good list of specialist dune slack bryophytes, with several rarities, recorded from Morfa Dyffryn, but the slacks we visited were a little disappointing and among the species we did not re-find are Amblyodon dealbatus, various uncommon Bryum spp., Moerckia hibernica and Riccia cavernosa. The best open slacks were rather dry and this may account in part for a poor showing among the mosses and liverworts. Nevertheless, Petalophyllum ralfsii was seen in a number of slacks, but always in small quantity and with a rather scattered distribution. Among additional species recorded were Bryum dunense, Homalothecium lutescens and Tortella flavovirens. Extensive stands of pleurocarps were examined and debated in two large slack complexes; Michael Proctor identified Drepanocladus sendtneri and Scorpidium cossonii, and other species recorded include Calliergon cuspidatum, Campylium elodes and Cratoneuron filicinum.

Figra Mine (SH 6619)

In the afternoon, various small groups visited Figra Mine on the hillside above Bontddu on the north side of the Mawddach estuary. It is an old disused copper mine and the probable locality for Cephaloziella nicholsonii collected by D.A. Jones in 1923. C. nicholsonii was unfortunately not re-found, but patches of C. massalongi were seen on damp rocks near the entrance to the old mine workings and elsewhere by Jonathan Sleath and others. There were also some fine patches of C. stellulifera on stony metalliferous soil. A large population of Leucobryum glaucum with many cushions bearing sporophytes was admired in an oakwood below the mine. A few small patches of Grimmia arenaria were spotted on a wall by the footpath leading to the mine.

Other localities

A few participants visited Llanelltyd Bridge (SH 7119) later in the day to pay their respects and photograph the well-known population of Grimmia arenaria. A separate small group visited Coed Ganllwyd NNR (SH 7224) to admire the relatively large colonies of Sematophyllum demissum which persist here; Campylopus setifolius, Drepanolejeunea hamatifolia and Sphagnum imbricatum ssp. affine were additional attractions. Another splinter group went to Coed Crafnant, a North Wales Wildlife Trust Reserve in the Artro valley (SH 6128), and recorded Leucobryum juniperoideum and Tritomaria exsecta among a range of commoner woodland species. All of these localities were also visited by small parties on other days of the meeting.

Sunday 14 April

Cwm Cywarch (SH 8419)

A large party set off in the morning in several cars for Cwm Cywarch in the Aran mountains. The weather was wet and quite cold which was a pity as this was the highest altitude locality (reaching about 700m) of the meeting. The objective was to work the extensive cliffs and crags in Cwm Cywarch. The majority of the group visited the northern part of the cwm, recording on stream-side rocks and higher ground at Creigiau Camddwr. A good range of the more common bryophytes found on acid rocks in the uplands of north Wales was examined, including frequent Gymnomitrion crenulatum and G. obtusum, together with Andreaea alpina, Dryptodon patens, Marsupella sprucei and a number of Racomitrium taxa. Species recorded on base-rich rocks include Anoectangium aestivum, Grimmia funalis, Isothecium myosuroides var. brachythecioides and Schistidium strictum. A smaller and more energetic group covered a large area of Craig Cywarch, and made a more impressive list, including Barbula ferruginascens, Grimmia torquata, Hedwigia integrifolia, Rhabdoweisia crenulata and Tetraplodon mnioides.

Torrent Walk (SH 7518)

Some of the party left Cwm Cywarch early and visited Torrent Walk, a well-known wooded ravine to the east of Dolgellau. A good list of woodland bryophytes was recorded, but Rhytidiadelphus subpinnatus (which has been seen here in recent years) was not re-found. On a separate visit to Torrent Walk earlier in the week, Nick Hodgetts and Ron Porley found Radula voluta.

Monday 15 April

Cwm Bychan (SH 6431) and the Roman Steps (SH 6530)

Situated at the head of the heavily wooded Artro valley, Cwm Bychan has a stand of oak-birch woodland through which a path leads to the Roman Steps (Bwlch Tyddiad) and the heather-clad Rhinog hills. The area is characterised by wild and rugged scenery and is reminiscent of hill country in western Scotland. The weather was mild with periodic light drizzle, and we followed the path out of the car park, soon noting Dicranodontium denudatum and Hylocomium umbratum in the woodland and Sphagnum molle in damp grassland. Most of the day was spent investigating the rocks and humid heathy vegetation by the Roman Steps in the Rhinog National Nature Reserve. Here a distinctive leggy heath community has developed over steep boulder-strewn ground, with a luxuriant bryophyte layer in which Sphagnum capillifolium, S. quinquefarium and other Sphagnum spp. are extensive. Bazzania tricrenata and Herbertus aduncus were both frequent, and other Atlantic hepatics observed include Anastrepta orcadensis and Lepidozia pearsonii (with bulbils); a few patches of Ptilium crista-castrensis were also admired. This is the only British locality for Gymnocolea acutiloba which was first detected here by D.A. Jones in 1911. It has often been re-found, and after our group had seen the first signs of Gymnocolea at lunch time, several good patches of G. acutiloba were observed on sheltered surfaces of boulders in NE-facing block scree. Other notable plants recorded in the rich welter of bryophytes included Anastrophyllum minutum, Campylopus setifolius, Grimmia torquata and Hypnum callichroum. When setting out for the Roman Steps, we had hopes but no great expectations of re-finding Glyphomitrium daviesii, Lophozia longidens, Sphagnum strictum or perhaps even Bartramidula wilsonii; sadly we had no success. However, our efforts were rewarded by the discovery of Campylopus brevipilus on slabby SE-facing outcrops. This species is surprisingly rare in north Wales and had not been recorded in Merioneth for over 90 years.

Before returning to Dolgellau, the organisers took Cliff Townsend to try to relocate Amblystegium saxatile at its second British locality in Cwmnantcol. The old peat cutting in which A. saxatile had been seen in 1987 was overgrown and now much wetter, and despite rooting around in litter at the base of Molinia tussocks, we were unable to re-find this rare and elusive moss. Material which looked promising when viewed through a rain-soaked hand-lens in the field proved to be either A. riparium or Campylium stellatum upon microscopic examination.

Tuesday 16 April

Hermon Copper Bog (SH 7425)

In the morning of the final day of the meeting a small remnant group visited Hermon Copper Bog which is a SSSI situated within the extensive Coed y Brenin conifer plantations. We were introduced to the site by Martin Garnett of Forestry Enterprise who gave an account of the highly unusual copper-enriched peat which in the past had been exploited to obtain copper. Higher plant metallophytes are represented by Cu-tolerant forms of Armeria maritima, Minuartia verna and Silene maritima. Specialist bryophytes are restricted to Cephaloziella massalongi which was seen in several places, characteristically on steep, moist soil banks, shaded by overhanging soil slumps, by the outflow stream running through the bog. The mire flora was also examined, and the bog surface has some large Sphagnum tussocks (mostly S. capillifolium and S. papillosum), with associated Cephalozia connivens, Kurzia pauciflora, Odontoschisma sphagni, Riccardia latifrons and several other bog liverworts. In a flushed zone, there were some nice patches of Sphagnum teres, which had not been recorded elsewhere during the meeting.

Craig y Benglog (SH 8023)

The final excursion was to the lightly wooded scree and crags of Craig y Benglog, which is part of a SSSI situated to the north of Rhydymain. The site is south-east facing, with variable shade from patchy oak-ash woodland, and there is some base-rich rock. The latter have extensive patches of Neckera crispa (in some cases with sporophytes), Pterogonium gracile, Tortella tortuosa and other calcicoles. Additional species recorded include Barbilophozia barbata, Frullania fragilifolia (on a tree trunk), Grimmia hartmanii and Plagiochila spinulosa. There were several large patches of Antitrichia curtipendula on rocks in the scree below the crags. It was a nice mixed site at which to conclude the spring meeting.

Uwch-y-coed (SN 8294)

After leaving the group before lunch, Ron Porley and Peter Martin drove south and stopped briefly at Uwch-y-coed, an impressive gorge near Machynlleth in Montgomeryshire (VC 47). Grimmia atrata grows in fair quantity on copper-rich rocks at this locality, and Coscinodon cribrosus, Ditrichum zonatum var. scabrifolium and Oedipodium griffithianum were also recorded.

Acknowledgements

We thank Peter Benoit for freely sharing his detailed bryological knowledge of the sites he visited with us during the meeting. We are also indebted for the help provided behind the scenes by our colleagues Fiona Evans, Annie Seddon, Doug Oliver, Rhodri Evans and Jonathan Neale in making access arrangements. Many landowners readily granted permission for the BBS to visit their property. Jean Paton kindly examined and confirmed material of Cephaloziella massalongi from Figra Mine and Hermon Copper Bog.

References

Armitage E. 1944. A short account of the Moss Exchange Club and the British Bryological Society. Berwick.

Hill MO. 1988. A bryophyte flora of North Wales. Journal of Bryology 15: 377-491.

Richards PW. 1979. A note on the bryological exploration of North Wales. Pp. 1-9 in: Clarke GCS, Duckett JG, eds. Bryophyte systematics. London: Academic Press.

Richards PW. 1983. The British Bryological Society 1923-1983. Cardiff: British Bryological Society.

Tim Blackstock and Marcus Yeo

Location:

Dolgellau, Gwynedd