Llanelli Naturalists Newsletter - Summer 1993 - No 55
Richard Pryce

Leader Richard Pryce.

Joint Meeting: Brecknock Wildlife Trust and Llanelli Naturalists.

The unsettled, windy weather contributed to the poor turnout for this meeting: only three members from the Trust and three from Llanelli Naturalists met the leader at Brynhenllys Bridge, Cwmtwrch (22 /756126). The gorge of the Afon Twrch at this locality is particularly attractive. However, the valley-side woodland had been suffering in recent years from intensive grazing by sheep entering from the adjacent fields and moorland.?. About two years ago, British Coal had fenced the extensive area in its ownership with a view to promoting its regeneration and already there has been a marked effect on the diversification of the woodland structure,

The small party took the footpath up the valley on the Brecknock side but progress was initially very slow as the leader was asked to demonstrate the typical plants of the canopy (principally Sessile Oak (Quercus petraea)), the shrub-layer (including Hawthorn (Crataegus monogyna), Hazel (Corylus avellana) and Holly (Ilex aquifolium)) and the diverse ground layer (for example Common Dog-violet ( Viola raviniana), Wood Sorrel (Oxalis acetosella), Yellow Pimpernel (Lysimachia nemorum) and Herb Robert (Geranium robertianum)). Philip Jones, mycologist from Llanelli, was able to point out various fungi on rotting wood including Coriolus versicolor and Honey Fungus (Armillaria mellea) but generally fungi were sparse. Bird song was rather difficult to hear due to the strong wind although the several species identified included Wood Warbler, Willow Warbler, Blackcap, Nuthatch and Blackbird.

A short stop was made at the foot of the unstable colliery tip at 22/760131 where plant colonists were seen to be of two types: Mouse-eared Hawkweed (Pilosella officinarum) was spreading by means of runners which helped to bind the shale surface to promote further colonisation and tiny annual plants represented by Thyme-leaved Sandwort (Arenaria serpyllifolia) and Small Cudweed (Filago minima), which are able to rapidly complete their life cycles from germination to seed-production and successfully beat any further collapse of the substrate.

The footbridge was crossed to the Carmarthenshire side of the river and remarks were made upon the recent unsympathetic "restoration" of the old lime kiln site (22 /762137). The old kilns supported a few fern species in the lime-mortar, including Maidenhair Spleenwort (A splenium trichomanes subsp. quadrivalens) and Hart's-tongue (Phyllitis scolopendrium). The path continued near the crest of the valley side and became very narrow and, in places, rather unstable. The well-drained, acid soils hereabouts (22 /765139) supported such plants as Sheep's Sorrel (Rumex acetosella), Early Hair-grass (Aira praecox) and Pill Sedge (Carex pilulifera) whilst occasionally Spring Sedge (Carex caryophyllea) was abundant where conditions became somewhat less acid.

Descending to near river level, a seepage in a valley-side hollow at 22 /766141 had developed into a small bog with abundant rush (Juncus spp.), Sphagnum, Common Cotton-grass (Eriophorum angustifolium) and several sedges. Locally, Bog Pondweed (Potamogeton polygonifolius), Bog Asphodel (Narthecium ossifragum) and Bog StJohn's Wort (Hypericum elodes) were frequent with Ivy-leaved Bellflower (Wahlenbergia hederacea) nearby. Two insect-digesting plant species were found growing on the wet crag to the north: Common Butterwort (Pinguicula vulgaris), with, its conspicuous yellowish- green rosettes was scattered over the rocks whilst Round-leaved Sundew (Drosera rotundifolia) was much more difficult to pick out, its reddish "tentacled" leaves being well camoflaged against the background of Sphagnum and grasses.

Time had passed quickly and evening was approaching. It was decided, however, that due to the strong wind, the group would of retrace its steps in the shelter of the valley in spite of the fact that only two days previously the leader had returned in brilliant warm sunshine, in shirtsleeves, over the exposed moor land route past Llwyn-yr-yn (22/764140) and Cwm-clyd (22 /762135) back to Brynhenllys bridge and to the "car park".