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SPRING FIELD MEETING 2008

Denbighshire, 3-8 April

Sarah Stille & Sam Bosanquet

 

The 2008 Spring Meeting was held in Denbighshire (VC50), in north-east Wales . The vice-county includes extensive outcrops of Carboniferous Limestone, reaching altitudes of over 450 m, and therefore has the potential to support a rich and diverse bryophyte flora. It has less dramatic topography and receives less rain than the heart of Snowdonia, so its Atlantic flora is restricted, but there is enough high ground to compensate. Its borderland situation has led to Denbighshire being overlooked by visiting bryologists en route to the west, and the vice-county remains one of the lesser well-known in Wales. The only systematic previous recording was done from Bangor in the 1970s and 1980s, summarised by Mark Hill (1988) so the meeting therefore had the potential to turn up some real surprises, as well as to fill in distribution gaps in preparation for the second edition of the Atlas (Hill et al., 1991–1994). It also offered a chance to see how things had changed since the 1980s, especially in the previously polluted areas of the vice-county’s north-eastern lowlands. Except for splinter group visits to the seriously under-recorded vice-county of Flintshire , VC51, we mostly stayed in VC50, but on two days the group ventured into VC48, Merioneth.

Headquarters for the meeting was in Llangollen, last visited by the BBS in 1938, which gives easy access to the Carboniferous Limestone, the Berwyn Mountains , the Dee Valley and various post-industrial sites. 40 people attended at the Hand Hotel for part or all of the week: Ian Atherton, Tim Blackstock, Sam Bosanquet, Brian Burnett, Des Callaghan, Rachel Carter, Nicholas de Sausmarez, Jo Denyer, Diane Dobson, Bob Ellis, Richard Fisk, Lorna Fraser, Mary Ghullam, Martin Godfrey, Jonathan Graham, Nick Hodgetts, Aline Horwath, Ann Hill, Mark Hill, Joan James, Liz Kungu, Mark Lawley, David Long, Pete Martin, Anna Mezaka, Oliver Moore, Graham Motley, Sharon Pilkington, Mark Pool, Ron Porley, Chris Preston, Gordon Rothero, Sumudu Rubasinghe, David Rycroft, Jonathan Sleath, Sarah Stille, Colin Wall, Mike Walton, Malcolm Watling and Jo Wilbraham.

Thursday 3 rd April

The first day was fine and sunny for the 15 people who met at World’s End (SJ232485) and as the party set off northwards Richard immediately found typically large Fossombronia caespitiformis*. The group then veered towards the first target, a stream flowing south from the limestone which however held only common acidic species lower down. Higher up there were patches of Drepanocladus cossonii, Palustriella commutata, Philonotis calcarea and others indicating more basic habitat. However, despite the mix of acidic and basic water Hamatocaulis vernicosus was not found in this locus classicus. Some people then continued to explore spoil heaps by the small exploratory shafts abounding on the moorland, while others visited side valleys and limestone outcrops. Sixteen taxa were added to the hectad list during the morning’s exploration of SJ24J, quite an achievement in an area that was regularly visited in the past. Many were acidophiles or flush species, suggesting that previous recorders concentrated on the limestone, but Entodon concinnus was a notable calcicolous addition. A non-bryological highlight was seeing three blackcock flying down the valley, and in the afternoon, the first wheatears of the summer.

More members arrived at lunchtime and then the party again split up, with a group driving to Rock Farm to attack the cliffs directly. This party – of David Long, Mark Lawley, Anna, Oliver, Aline and Sumudu – explored a valley in SJ2245. Calcareous rocks and soil yielded a rewarding range of calcicoles, including Brachythecium glareosum, Campylium protensum, Ditrichum gracile and D. flexicaule, Entodon concinnus, Pottia davalliana, Tortula lanceola, T. subulata, Conocephalum salebrosum and Preissia quadrata. Others headed south along Offa’s Dyke Path to Eglwyseg Mountain (SJ24I), returning along the clifftops, or walked along the road working the lime kiln and a ford. The most notable species in this southern section were Apometzgeria pubescens and Cololejeunea calcarea on limestone, the latter new for the hectad, and Porella arboris-vitae, Pohlia cruda and Weissia brachycarpa var. obliqua. Nick Hodgetts went up to the World’s End cliffs (SJ2347) where he was pleased to find Plagiopus oederianus and Entosthodon muhlenbergii . In the evening people met for a short introductory presentation outlining the week’s plans, followed by dinner at the hotel.

Friday 4 th April

Spl intering was underway early; Mark Lawley, Oliver and Sharon took advantage of a mild, dry day, before the forecast wintry conditions, to explore Llyn Arenig Fawr ( SH8437, 8438 & 8439; VC48) . This was unremittingly acidic terrain; nevertheless, 119 species went on the card, of which 38 were liverworts. Grimmia donniana grew by the lane, and a drystone wall leading to the lake held Barbilophozia atlantica. Bazzania trilobata appeared in a patch of Mylia taylorii on the shore, Cephalozia lunulifolia, Nowellia curvifolia, Scapania scandica and Tritomaria exsecta grew together on a rotten tree trunk, and Ptilidium pulcherrimum on decorticated wood beside a stream. A lip of peat near the lake held Kurzia sylvatica, and K. trichoclados was on the cliffs above. Gymnomitrion obtusum and Scapania umbrosa were growing on rock. Best of all, a couple of huge boulders by the lake held impressive amounts of the diminutive Marsupella alpina, which though not new to the site (Hill, 1988) is rare in Wales . The most notable moss found was Rhabdoweisia crenulata, a few tiny colonies of which grew in rock crevices.

At the car park at Trevor canal basin (SJ270422) the rest of the party avoided car shuttling by crossing the 180 foot high Telford aqueduct both ways on foot. The towpath is only about three feet wide, and from it we had fine views of narrow boats negotiating the seemingly impossibly-restricted channel over the valley, as well as vertiginous vistas towards the Cheshire plain downstream and westwards to the Welsh mountains. Long before reaching the small quarry above Froncysyllte (SJ269411) the party had spread out, indeed perhaps not everyone ever arrived! After a quick once-over of the quarry, two parties set off to give long-neglected Flintshire (VC51) some attention. The rest drew up a respectable list for the quarry area, which proved typical of the north Wales limestone and included Eurhynchium striatulum, Fissidens gracilifolius, Gyroweisia tenuis, Mnium stellare , fruiting Campylophyllum calcareum , and Plagiochila britannica, amongst commoner calcicoles. Small groups drifted back over the aqueduct for a summery picnic lunch by the canal, before clambering down through woods to the riverside, where sheets of Homalia trichomanoides made a splendid display.

The two Flintshire splinter groups had varying fortunes. Chris Preston, Jonathan Sleath and Aline recorded in the conifer plantation of Coed Moel Fanog (SJ16Q). They found a good range of epiphytes, including Colura calyptrifolia on willow by a stream, Orthotrichum lyellii, O. stramineum and O. striatum, whilst conifer stumps had Plagiothecium curvifolium. Unfortunately, the vagaries of vice-county boundaries confounded the team, and it turned out that they were in Denbighshire (VC50) rather than Flintshire. Despite this disappointment, 12 taxa, 10 of them epiphytes, were new to the hectad. David Long, Sumudu, Anna, Mark Hill, Rachel and Richard also headed for Flintshire, this time successfully. They chose a stretch of the Afon Alun near Cilcain (SJ16X; VC51), where a mixture of woodland and limestone rocks produced over 90 species, including Schistidium elegantulum subsp. wilsonii* in limestone scree, and Marchesinia mackaii ,Neckera crispa, Plagiochila britannica and Taxiphyllum wissgrillii. Orthotrichum stramineum* was also collected for the vice-county.

En route north, Sam and Graham recorded at four sites in the Llangedwyn area in SJ12 (VC50), including the igneous outcrop of Craig Orllwyn. This supported little more than abundant Grimmia trichophylla and Hedwigia stellata on south-facing acidic rocks, but a much more diverse assemblage of calcicoles, such as Campylopus fragilis, Fissidens osmundoides, Frullania fragilifolia, Plagiochila killarniensis, Porella arboris-vitae, Reboulia hemisphaerica, Schistidium strictum* and Tortella bambergeri*, on its sheltered north side, where seeping water was causing higher pH levels.  Prolonged searching by Graham eventually revealed Schistostega pennata in a rabbit hole.

Saturday 5th April

The day dawned fine and sunny again and the whole party gathered at the Minera lead mines (SJ276508), now restored as an industrial archaeology visitor centre where the spoil heaps had long ago been landscaped to prevent lead-bearing dust affecting local residents. Despite this, a good range of bryophytes persisted: Bryum pallescens and Weissia controversa var. densifolia were particularly abundant, and a metal-tolerant form of Brachythecium velutinum with strongly falcate leaves received much attention. The spoil was almost universally base-rich, so even the most frost-heaved spoil failed to produce Ditrichum plumbicola, although another metallophyte, the strikingly long-peristomed Pottia starkeana*, was consolation. The only Cephaloziella collected, by David Long, turned out to be C. divaricata rather than a more exciting lead mine specialist. Humid willow scrub was reasonably epiphyte-laden and supported Metzgeria fruticulosa* as well as M. temperata.

Before long everyone moved on to Minera Quarry (SJ258519) and the party split in two: the southern group went due west and south to keep within one tetrad (SJ25K). They traversed out onto steep grassland where limestone outcrops produced an interesting suite of species including Dicranum bonjeanii, Riccardia chamedryfolia and Tritomaria quinquedentata. After lunch they explored an interesting lime-rich and very wet gutter at the eastern edge of the tetrad. Other highlights in the area included Leucodon sciuroides on ash, Leiocolea badensis, Preissia quadrata and the by now familiar calcicoles Didymodon ferrugineus and Entodon concinnus. Later the local farmer told them of great spots they should have visited, such as the deep gully at the far end of the big quarry – there are definitely many rich places at Minera that remain unexplored!

The northern group worked the woodland, quarry edge and fields above the exposed floor in SJ25L. Notable finds included more Pottia starkeana on exposed soil on the quarry side, Porella cordaeana on a tree base, Encalypta vulgaris and Tortula lanceola among rocks at the top of the quarry, Weissia longifolia var. angustifolia on soil, and Entodon concinnus, Thuidium assimile and T. recognitum in calcareous grassland. The willows, hawthorns and hazels around the quarry supported a wide range of saxicolous mosses, including locally abundant Encalypta streptocarpa, Grimmia pulvinata, Orthotrichum anomalum, Schistidium crassipilum, Tortula muralis, and a little bit of Orthotrichum cupulatum. It is traditional to ascribe the appearance of such epiphytes to the presence of limestone dust on the trees, but the quarry has been disused for some years, the mosses grew even on young branches in a sheltered valley, and there was no visible sign of dust on the bark. Leskea polycarpa and Syntrichia latifolia were also noted as epiphytes in the same area, a long way from their usual waterside haunts.

After lunch, Mark Hill, Liz and Sam abandoned the northern group in favour of Nant y Ffridd (SJ2654) in VC51. The descent through forestry on this famously ‘ruined’ site produced Orthodontium lineare, and Aulacomnium androgynum on the side of a large boulder but none of the hoped-for Orthodontium gracile. Denbighshire was steadfastly avoided as the party worked down the north bank of the stream, recording Colura calyptrifolia on a sycamore, and Didymodon spadiceus*, Heterocladium heteropterum var. flaccidum*, Porella cordaeana and Lejeunea cavifolia* on rocks. A rock face above the track back out of the valley produced Tortula marginata*. The epiphytes were reasonably diverse and included Microlejeunea ulicina*, Metzgeria temperata* and copious Orthotrichum stramineum, as well as the three common Ulota spp. U. bruchii, U. crispa and U. phyllantha.

(all * not collected).

Before dinner, Publications Committee and Conservation & Records meetings were held and then after another well-attended meal (with 34 members), Jonathan Sleath eventually managed to drag members away from the table for the Council Meeting around 8.30pm.

Sunday 6th April

Overnight snow had been forecast, but it was still a shock to look out of the hotel windows in the morning and find a 4cm blanket of moss-smothering whiteness. This drove Gordon home to Scotland , but everyone else proved of sterner stuff and gathered at the car park in Glyndyfrdwy ( SJ148426; VC48) to walk south to the ruined slab-machining shop at Nant y Pandy (SJ1441). This is a Scheduled Ancient Monument , so we had been asked not to collect specimens from the masonry though only some very large Tortula subulata proved tempting. Its environs (SJ14K) held a range of humidity-demanding bryophytes that had not been seen previously during the meeting, including Sphagnum quinquefarium, Scapania gracilis, Plagiochila spinulosa, Riccardia palmata and some of the large Aneura that is receiving attention from David Long and his team. David also found Schistostega on a lane bank at SJ144417. A total of over 130 taxa was the highest for a single tetrad made during the week and included more than 20 additions to the hectad total despite this being a relatively well-recorded area. On the way, a small group also recorded in SJ14L, where highlights included further upland-edge species, such as Barbilophozia attenuata, Metzgeria conjugata, Scapania nemorea and Tritomaria quinquedentata.

Ron, Pete and Oliver soon decided that the cliffs below Cadair Berwyn (SJ03) were a more attractive and challenging prospect and set off to walk over the ridge to Bwlch Maen Gwynedd. Unfortunately, the weather on the summits worsened and although they had the snowy northerly wind at their backs, progress was too difficult for them to reach the cliffs or do much bryologising. However they were pleased to find Dicranoweisia crispula and Kiaeria blyttii on the VC48 side of the boundary at the Memorial Stone SJ091366.

After the machining shop the main party made its way up to the disused slate mine at Moel y Fferna (SJ125399), over unimproved but fairly uninteresting grassland. Here, in relative shelter, the snow was limited to sharp, blustery showers of soft hail, which had the advantage of not getting the group too wet. The first people reached the mine in time to have a sunny but chilly lunch between the showers, before exploring the extraordinarily rotten and calcareous slate of the spoil heaps. Copious Ctenidium molluscum indicated base-richness, and soon Mark Lawley re-found the Tortella inclinata and Distichium capillaceum, collected on an earlier recce; T. tortuosa, Encalypta streptocarpa and Bryoerythrophyllum recurvirostrum were also seen.

Another excursion to Flintshire (VC51), by Chris, Jo Denyer and Aline, had the aim of refinding Phaeoceros laevis at Flint Castle (SJ2473). As on the Friday, misfortune struck: the group had been told to go to the wrong castle (Hill, 1988 gives the only north-east Wales record for P. laevis as Ewloe Castle)! A beneficent deity might have provided P. laevis at Flint Castle as a reward, but the site was almost an urban park in character and held little more than Didymodon luridus* and another 25 ‘grots’. Luckily the nearby Nant-y-Flint SJ27F produced a good list of over 60 taxa in recompense, including 18 that were new to the hectad.

Monday 7 th April

With the weather once more dry everyone gathered in the small village of Sarnau (VC48) prepared for a really wet site, the North Wales Wildlife Trust’s Cors y Sarnau reserve (SH93U) . One group went “anti-clockwise” with Graham Berry, NWWT Conservation Officer, Kathryn Birch (CCW) and Andrew Graham, a voluntary warden. In the wet woodland at the east end, they found fruiting Calliergon cordifolium, as well as Campylium stellatum, Climacium dendroides, Drepanocladus cossonii, Fissidens adianthoides, Plagiomnium ellipticum and Rhizomnium pseudopunctatum in more open fen. The other group explored woodland and fen at the western end before splashing through relatively deep water to the main valley mire. Here Sphagnum magellanicum was found, indicating that parts of the open fen are becoming ombrogenous, as well as several other Sphagna including S. squarrosum and S. teres, indicating slight base-enrichment. Richard successfully hunted for Cryptothallus , new to the site, under Sphagnum in birch scrub. Colura was spotted on a birch and Sanionia uncinata was fruiting on willows – Colura now seems to be scattered on scrubby wetlands in Wales, as well as in conifer plantations, which would have been unheard of in the 1980s (Hill, 1988).  This group then traversed the woodland before meeting up for lunch in the village, having failed to re-find Pseudobryum cinclidoides

In the afternoon the party split into several groups. Lorna, Ann, Joan and Rachel visited t he enticingly named, but bryologically unpromising “Get Wet Adventure Co.” site at Coed Craig Crogen (SJ014369). There was an impressive quantity of lush-looking moss on wet rock faces, but the tiny Rhabdoweisia crispata was the most interesting of the 49 species recorded. Another group visited the dramatic gorge above Cynwyd (SJ0640), where humidity-demanders in the gorge included Lejeunea lamacerina, Plagiochila killarniensis, P. spinulosa, Scapania gracilis and saxicolous Metzgeria temperata, as well as Amphidium mougeotii, Oreoweisia bruntonii and Porella cordaeana. The nearby reservoir held more mundane species, such as Bryum ruderale and Fossombronia pusilla. Elsewhere, exploration of the Afon Erwent (SH83G) produced 30 fairly typical upland species, including Polytrichum strictum and Hyocomium armoricum, whilst visits to bulldozed colliery spoil at Johnstown (SJ3045) revealed 38 taxa, and intact colliery spoil at Rhostyllen (SJ3148), (33 species), included a few surprises like Amblystegium varium, Campylium protensum and Scapania scandica.

Tuesday 8 th April

With the sun once more shining, the remaining participants (19), returned to the disused Pistyll Gwyn limestone.Quarry to walk north up the lane towards Bryn Alyn SSSI (SJ15Y/Z). Mark Lawley found Didymodon acutus* on thin soil over tarmac in the lane, then Pottia davalliana in a small quarry – only the second time this diminutive acrocarp was seen during the week. A footpath led on to the quarrying village of Nant, now being gentrified like so much of this area, and thence to some disused lead mines (SJ25D) with their nearly-flowering Minuartia verna. As on previous days, the mines were highly calcareous, with abundant Bryum pallens, B. pallescens and Dicranella varia, as well as Entodon concinnus (at SJ200575) in surrounding grassland. Several Orthotrichum species in nearby scrub were new for the hectad, including O. pulchellum and O. stramineum. After an early lunch most people left for home, David Long pausing en route to grab Syntrichia virescens* and Leucodon sciuroides from laneside ash trees at SJ192571.

A small remaining group retraced their steps and walked northwards towards Bryn Alyn SSSI. The limestone pavement above the path and an interesting scrubby wood on rubble and limestone provided final distractions before their return to the car park down steep grassland with wonderful views over the Clwydian AONB

Finally, Sunday’s Flint/Ewloe Castle mistake was remedied by a visit to the latter (SJ2867; VC51) by Aline, Chris, Jo Denyer and Mark Hill. Unfortunately, Phaeoceros laevis could not be refound, but the tally of 50 taxa around the castle and by the Wepre Brook included seven new for the hectad and a few interesting calcicolous highlights, such as Fissidens gracilifolius, Mnium stellare, Conocephalum salebrosum and Leiocolea turbinata.

Summary

During the week over 2,700 bryophyte records were made from more than 30 different sites in 14 hectads. A remarkable level of geographical precision was achieved with all but a handful of records being made at tetrad level or better. Nine taxa were added to the known bryophyte flora of Denbighshire (VC50) and 14 to the poorly-known Flintshire (VC51) flora, although a few in VC51 were not collected as vouchers . In addition, the segregates Barbula convoluta & B. sardoa, and Conocephalum conicum & C. salebrosum, which were not recorded in the last Census Catalogue, were found in VCs 48, 50 & 51; Lophozia ventricosa var. ventricosa was identified in VCs 48 & 50; and Schistidium apocarpum s.s. and S. crassipilum were confirmed as both occurring in Merioneth (VC48).

Even the best-known hectads had several new taxa recorded, and at least 280 additional hectad records were made. The greatest increases were for SJ25 (Minera & Nant y Ffrith; 83 additions) and SJ24 (Eglwyseg, World’s End, Froncysyllte etc.; 78 additions), which is astonishing, and suggests there have been genuine changes as well as past honey-potting. If Ulota bruchii (included with U. crispa in the Atlas) is excluded then the most new hectad records were made for Metzgeria fruticulosa (6 new hectads) and Campylopus introflexus, Cryphaea heteromalla, Orthotrichum pulchellum & Syntrichia ruralis (all 5 new hectad records). Epiphytes are particularly prominent, with Radula complanata & Ulota phyllantha (4 new hectads), Colura calyptrifolia, Orthotrichum lyellii, O. stramineum and O. striatum (3 new hectads) backing up our general impression that air pollution is much less significant in north-east Wales now than in the 1980s (Hill, 1988).

The five most widely-recorded species were Bryum capillare, Brachythecium rutabulum, Calliergonella cuspidata, Eurhynchium praelongum and Rhytidiadelphus squarrosus, all of which were seen at 28 or more sites. Lophocolea bidentata, Pseudoscleropodium purum and Thuidium tamariscinum were also predictably ubiquitous, but Orthotrichum affine made a rather surprising appearance in the top 10, and O. pulchellum and O. stramineum were each noted at a remarkable 17 sites. Frequent visits to limestone sites is reflected by Ctenidium molluscum and Fissidens dubius being found more than 18 times, whereas the common acidophiles Hypnum jutlandicum and Polytrichum juniperinum were only noted on 15 occasions. Entodon concinnus, which was described as “very rare” by Hill (1988) and was previously only recorded for Denbighshire from Minera, was seen at eight different sites, although this might indicate that it was missed in the past in this under-explored area.

Attendees may have expected North Wales to produce numerous montane and oceanic species, but Denbighshire’s easterly position made this unlikely. Analysis of the species recorded shows that well over 60% of records were of essentially temperate bryophytes. (Table 1) Most northern taxa were found at mine spoil sites and at Llyn Arenig Fawr, although the limestone around Creigiau Eglwyseg also held northern plants. The few recorded Mediterranean taxa were all on the limestone and in Flintshire. Comparison with the adjacent vice-county of Caernarvon (VC49), which includes the heart of Snowdonia, reveals a much lower percentage of northern and montane species on this meeting’s list than in that vice-county, but also a lower percentage of Mediterranean taxa. This reflects the fact that the meeting avoided the more extreme habitats suitable for these elements.

 

 

2008 meeting

 

Caernarvon

Major biome

Code

Taxa

Percentage

Percentage

Arctic-montane

1

1

0

3

Boreo-arctic montane

2

27

8

12

Wide-boreal

3

15

4

3

Boreal-montane

4

23

7

16

Boreo-temperate

5

131

37

24

Wide-temperate

6

18

5

2

Temperate

7

82

23

21

Southern-temperate

8

28

8

10

Mediterranean

9

27

8

9

Total

 

352

100

100

 

Hyperoceanic and oceanic bryophytes were also notably absent (Table 2), and nearly half of the species recorded during the meeting show circumpolar distributions. The paucity of gorges in Denbighshire, and our avoidance of honey-potted sites, has led to this poor representation.

 

 

2008 meeting

Eastern limit category

Code

Taxa

Percentage

Hyperoceanic

0

7

2

Oceanic

1

11

3

Suboceanic

2

67

19

European

3

98

28

Eurosiberian

4

5

1

Eurasian

5

4

1

Circumpolar

6

160

45

Total

 

352

100

 

Surprisingly, relatively few Nationally Scarce taxa were found, given the limestone habitats and most of those were somewhat predictable. Stars of the show were Plagiopus oederianus and Entosthodon muhlenbergii at World’s End; Ditrichum flexicaule at Creigiau Eglwyseg; Eurhynchium striatulum at Froncysyllte; Marsupella alpina and Tritomaria exsecta near Llyn Arenig Fawr; Tortella inclinata at Nant y Pandy; Cryptothallus mirabilis at Cors y Sarnau; Pottia starckeana at Minera; Thuidium recognitum at Minera Quarry; and Didymodon acutus at Eryrys.

References

Hill, M.O. (1988), A bryophyte flora of North Wales , J. Bryol.15: 377–491.

Hill, M.O., Preston , C.D. & Smith, A.J.E. (1991–94), Atlas of the Bryophytes of Britain and Ireland . Harley Books.

   
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