Field meeting weekend in South Wales 12-13 March 2005

This meeting aimed to check for the semi-slug Phenacolimax major in the western part of its recorded range, as part of the Conchological Society’s survey throughout England and Wales (see Mollusc World Issue 3 page 3 and picture on page 13). Five of us met at Talgarth - John Evans, John Harper, David Porter, Tony Smith and I, and we then went to Pwll-y-Wrach Nature Reserve (visited by kind permission of the Brecknock Wildlife Trust) , where Rosemary Hill and Ron Boyce joined us.

Pwll-y-Wrach, (SO/165326), is a mixed deciduous woodland in a narrow valley in Old Red Sandstone, cut by the river Erig on the south west side of the Black Mountains. The higher slopes are dominated by Oak but nearer the river, where it is more base-rich with pockets of re-deposited lime, there is more variety including Ash. Opposite-leaved Golden Saxifrage, Chrysosplenium oppositifolium, was noted near the stream. P major had been found here during a Society field meeting in 1994 (information from Ron Boyce), so it was with some relief that two live animals were found, one in Oak litter about 20m above the river and the other in moss over soil. Other molluscs were varied, if not in large numbers - the table below lists them and earlier records. Possible old woodland indicators, besides P major were Perforatella subrufescens, Azeca goodalli, which can turn up in more open sites, and Helicigona lapicida, also found on rocks and dry stone walls. We did not refind Leiostyla anglica which John Harper had found near the stream in 2003, but it could well be still present.

Pwll-y-Wrach Molluscs

(previous records are from a Conchological Society Meeting 14.5.1994 (CS), and John Harper (JH) 2003-2004)

In the afternoon, by kind permission this time, of the Countryside Council for Wales (CCW) we visited Craig-y-Cilau National Nature reserve (SO/185165), a north facing escarpment with lower slopes in Old Red Sandstone and upper cliffs in Carboniferous Limestone. There is an area of boulder scree below the cliffs, on which slightly open deciduous woodland has developed. We concentrated on recording in this area. No living P major was found but nor any reliably identifiable shell. Records held by the Countryside Council for Wales included, intriguingly, Acicula fusca and Malacolimax tenellus. It was much too early to search for the latter but we did find Acicula fusca, mainly the white form, in ground litter and moss from below boulders. One Limax cinereoniger was found under a large stone. Other species found are listed right.

Craig-y-Cilau Molluscs

Note: CCW records are given as from “Bray 1977, ILEA 1981, Lowe 1986, master from Fowles 1988”

The Taf Fechan Nature Reserve lies in the beautiful valley of the southwest flowing Taf Fechan river just south of the border of the Brecon Beacons National Park. Geologically it lies on the northern rim of the South Wales coalfield. It is a mixed habitat reserve with a river, grassland, wooded slopes, springs and flushes, and stone walls, along a valley in Carboniferous Limestone.

Tony Smith and David Porter were unable to be at the Taf Fechan area (SO/04-09-) on 13 March. Many thanks to the Glamorgan Wildlife Trust for permission to visit this. Most of our recording was at the base of a wooded slope at SO/043093 lime encrusting springs and flushes, but we also looked at grassland, and stone walls. Perhaps the greatest surprise was a fresh Balea perversa shell found in a sloping wet flush.

Taf Fechan Nature Reserve molluscs

(John Harper’s records are i) for the reserve SO 044097 on 27.9.2004, and,ii) marked “o”, for additional species for the Taf Fechan area but outside the reserve for the period 2002-2005)

Unplanned recording outside the field meeting included a brief stop at a strip of mixed deciduous woodland by Talybont reservoir (SO/098194) near where Peter Dance recorded P major in 1971 which produced a possible dead shell of that species. And John Harper took us to a limestone exposure with short turf above Pont Sarn at SO/049095 which had one live and over 100 dead Helicella itala.

With many thanks to: The Brecknock Wildlife Trust ( Tim Breakwell and Diane Morgan), the Glamorgan Wildlife Trust ( Diana Clark), and the Countryside Council for Wales (Richard Preece) for permissions to visit and information about their reserves; all participants for the effort they put into recording each day; John Harper for many suggestions as to sites, information and guidance on how to find them and records with permission to include them here,and Ron Boyce for the May 1994 records. Richard Preece also gave permission for the CCW records from Craig y Cilau to appear here.

Fig 1. Trees at Pwll y Wrach

Fig 2. Waterfall at Pwll y Wrach

Fig 3. Old wall in Cwm Taf Fechan SO 044097

Fig 4. REH at Craig y Cilau

Fig 5. Craig y Cilau SO 185169

Fig 6. John Evans at Craig y Cilau

FIg 7. David Long, John Evans and REH in Cwm Taf Fechan SO 044097

Fig 8. Tony Smith at Craig y Cilau SO 185169

Fig 9. Phenacolimax major.

Fig 10. Snail Cochlodina laminata with unpigmented shell.