Summer meeting 1992: The Uists & Benbecula

HomeEventsSummer meeting 1992: The Uists & Benbecula

5 August 1992 - 12 August 1992

Meeting report

On the evening of 5 August I waited for two hours in the bar of the Creagorry Hotel with a force 10 gale blowing outside. By 10 o’clock I was planning my return to Edinburgh for the following day, but at 10.15 four of the BBS arrived, variously sick, windswept and exhausted from the Uig ferry. The following morning there were eight of us, the wind had dropped and it was fine but cold. The weather continued to improve and we had a thoroughly interesting and enjoyable week.

We visited several ‘machair’ sites on the west coast of the Uists and Benbecula. Machair is the name for the sandy plain which runs more or less continuously north-south along the length of the islands, and east-west along the coast of North Uist and Berneray. Much of it is quite flat though, here and there, there are dune-systems with a more usual formation of dunes and slacks. The flat machair is, or has been extensively cultivated, but there are wetter, fenny areas where the machair joins the ‘blackland’ which are bryologically interesting. The dune slacks, where they are well developed, are very rich.

The mountains are Lewisian Gneiss, and are therefore hard and acidic. They are approached across blanket bog most of which is exceedingly dull, probably because it has been burned too frequently. Parts of the upper slopes are very heavily grazed and are similarly of little interest. But the steeper and less accessible parts have areas of tall heather and ledge communities that contain several of the more interesting Atlantic hepatics.

We also visited two of the smaller islands, Berneray and Pabbay.

Machair Sites

1. Loch Hallan (735 225) 6 August

We spent several hours in the fen at the north end of Loch Hallan. Progress was slow because the water was deep and round much of the area there were tall reeds (Phragmites is dominant over an area of about 15 ha). There was also much discussion over the identity of Calliergon and Drepanocladus specimens. The following were recorded: Calliergon cordifolium, C. giganteum, Drepanocladus aduncus, D. lycopodioides, D. sendtneri, Campylium elodes, Plagiomnium elatum, P. ellipticum and Philonotis calcarea. There were large and spectacular patches of Marchantia polymorpha (the old and beautiful var. aquatica).

We returned to Askernish House by a drier route (we had by no means done a complete survey of the fen) and recorded Leptobryum pyriforme and Brachythecium mildeanum on the way. Harold Whitehouse collected specimens of several species of Bryum from fallow cultivated ground including B. dunense*, B. rubens and B. ruderale*.

2. Benbecula Aerodrome (790 570) 6 August

We drove across the runways of the airfield escorted by a rescue vehicle, we then bounced through several hundred yards of dunes and parked close to the site of the wheelhouse at An Tom. Most of this area of dunes is dry and bryologically dull (ragwort, marram grass and Rhytidiadelphus triquetrus). But there is one exceptionally rich slack. This is marked as standing water on the 1:50,000 O.S. and, as you approach it, looks very unprepossessing. It is littered with rusting scrap, old tyres and various other military rubbish; indeed it is difficult to tell whether the slack itself is natural, or whether it has been excavated. The lowest part is Carex nigra/Calliergon cuspidatum and unremarkable, but the slightly higher ground on the SE and SW sides is covered by tufts, patches and sheets of Distichium inclinatum, Catoscopium nigritum and Meesia uliginosa. We also saw Amblyodon dealbatus, Barbula reflexa, Moerckia hibernica and Riccardia incurvata* here. Amblyodon and Moerckia were much less abundant than I noted in 1983 (‘frequent’), but Amblyodon was difficult to spot because its leaves had turned black rather earlier in the season than usual. Meesia and Catoscopium were both more abundant than I remember them.

By the bank at the NE end of the slack, growing on old crumbling tarmac were beautiful sheets of Encalypta rhaptocarpa. Martin Wigginton collected Barbula trifaria* here, a considerable extension beyond its previously known limits in Wigtown and Banff.

3. Baleshare (790 600) 9 August

Baleshare is a small island connected to N. Uist by a ½-mile causeway. The southern half is a dune system, with high dunes to the western edge, and lower dunes and flatter slack-like areas in their lee. The northern part of the machair has been enclosed by fences, and new areas have been cultivated in recent years. Among some of the older turf, and outside the fences at the head of the saltmarsh of the NE shore of Traigh Eachkamish we found Amblyodon dealbatus, Jungermannia atrovirens, J. exsertifolia ssp. cordifolia and, in the saltmarsh, Lejeunea patens and Frullania tamarisci. Further south towards the far end of the enclosed ground we found Moerckia hibernica, Meesia uliginosa (both locally abundant), Catoscopium nigritum and Distichium inclinatum. Beyond the fences a path continues through miniature dunes which open out into a wide flat expanse of slack-like vegetation. On very slightly raised patches of sand either side of the path Tortella inclinata grows. At first it does not stand out well from the Distichium capillaceum with which it grows but when it is dry the straight leaves and the bright, matt, pale green colour are distinctive.

In the lowest-lying area, which is apparently flooded by the sea several times every winter, bryophytes are prominent in the vegetation. Calliergon cuspidatum and Drepanocladus revolvens are, of course, common, but there are quite large areas dominated by Campylium elodes and Cratoneuron filicinum, growing in a close mixture and looking astonishingly alike. We also recorded Campylium polygamum.

4. Balranald and Hougharry (705 705) 9 August

A few of us spent a short time in the fen which extends to the south and west of Loch nam Feithean. Its appearance in August is spectacular because grazing animals are excluded and the plants, in particular Pedicularis sylvatica which is very abundant, are allowed to flower. Drepanocladus sendtneri, D. uncinatus, Campylium elodes, Calliergon cordifolium, C. giganteum and Plagiomnium ellipticum were recorded. Harold Whitehouse looked at an oatfield at Hougharry and collected B. klinggraeffii, B. rubens and B. ruderale.

Mountain Sites

1. Beinn Mhor (809 311) and Allt Volagir (800 295) 8 August

The day of the main mountain excursion was gloriously fine. We climbed Beinn Mhor from Locheynort and the route turned out to be rather steeper than we had expected. We spent much of the morning however in and around the scrap of woodland on the Allt Volagir (800 294). This is the only native woodland in the Outer Hebrides. It consists of a handful of aspen, hazel, rowan and ash trees, clinging to the steep bank of the stream cutting. I am ashamed to admit that I had more or less dismissed its bryological interest on an earlier visit because of its pathetic size and its midge population. The Nick Hodgetts party was much more tenacious and found Frullania fragilifolia, F. microphylla, F. teneriffae, Aphanolejeunea microscopica, Drepanolejeunea hamatifolia, Harpalejeunea ovata, Lejeunea lamacerina, Colura calyptrifolia, Ulota calvescens and Glyphomitrium daviesii. Harold Whitehouse and I found Campylopus brevipilus in an otherwise dull patch of bog to the north of Loch nam Faoileann.

The fragmented party reunited for lunch on the summit of Beinn Mhor, from where we could see all the watery mosaic of the Uists sparkling in the sun, St Kilda to the west and, north and south, the length of the Hebrides.

On the north and north-east slopes of the hill, which are quite different from the dull grassy south-facing slopes, we found a rich assortment of hepatics, growing on banks and ledges or among tall heather and boulders: Anastrepta orcadensis, Bazzania tricrenata, B. pearsonii, Herbertus aduncus, Mastigophora woodsii, Plagiochila carringtonii, Scapania ornithopodioides and S. nimbosa. Harold collected Campylopus schwarzii.

We returned to Loch Eynort by Bealach Crosgard, accompanied by two walkers, she young and silent, he about ten years older, talkative and inquisitive. We found Campylopus shawii near the bealach, (Martin Wigginton also found Pohlia muyldermansii* and Cephalozia macrostachya* during the course of the day) but arrived at the vehicles mentally and physically drained.

2. Hecla (825 345) 11 August

On the last day, after the rest of the party had departed, Harold and I climbed from the deserted village of Lochskipport into Choire na h-Eitich, below Ben Scalavat. We again found Anastrepta orcadensis, Herbertus aduncus, Mastigophora woodsii, Plagiochila carringtonii and Scapania ornithopodioides, growing in tall heather at about 250-300m. Harold took a lot of stereo photographs and we returned in cold, heavy rain.

Smaller Islands

1. Pabbay (890 880) 7 August

Pabbay lies in the Sound of Harris, at the Atlantic end, roughly mid-way between North Uist and Harris. A hundred years ago it had three hundred inhabitants, now it has none. There is one house that the owner uses occasionally, about a thousand sheep, and a small domesticated herd of red deer. It is botanically interesting because the whole of the south slope (more than half of the island) is covered by calcareous blown sand, forming a ‘climbing’ dune system. Much of this sand is damp from water percolating down the slope, and it supports a rich variety of calcicolous plants. We travelled to the island in the boat used to transport the sheep, which is also the reserve boat for the Berneray Ferry. It has a huge engine (reassuring) but no seats (uncomfortable) and cost us £10.00 per head (the equivalent cost for a sheep would be less than 50p).

Among the dunes, flushes, slacks and grassland of the south side of the island we found Amblyodon dealbatus, Barbula reflexa, Distichium inclinatum, Encalypta streptocarpa, Neckera complanata, Orthotrichum cupulatum*, O. rupestre, Leiocolea alpestris*, Meesia uliginosa, Riccardia incurvata, Riccia beyrichiana, Tortella fragilis, Philonotis calcarea and a long list of commoner bryophytes.

We had lunch below the summit of Beinn a Charnain (196m) where we found Archidium alternifolium and, just to the north of the summit, Salix herbacea (this must be one of its lowest sites in Britain). We spent most of the afternoon looking at the north and north-east slopes of the island, where we found Myurium hochstetteri, growing reasonably frequently on rock ledges, in turf and here and there on open peat. Radula aquilegia was also seen growing on wet, almost bare peat. On one exposed line of rock running down towards Brenish Point, we found Frullania fragilifolia, F. teneriffae, Harpalejeunea ovata, Saccogyna viticulosa, Odontoschisma elongatum* and Colura calyptrifolia. Nick Hodgetts found Sphagnum platyphyllum somewhere on the island, and one of us (not me) got lost in the sand dunes on the way back to the boat.

2. Berneray (910 820) 10 August

The ferry to Berneray is a much more sedate affair. Half the party arrived at the jetty after it had departed, but it came back for a second trip. Berneray has a massive dune and machair system, three miles long by a mile wide, more than half the area of the island. A large part of it has been cultivated for a long time (probably several thousand years), but we saw none of it under cultivation in 1992. The slacks and damp, low-lying areas are bryologically rich (it is one of the best machair sites), but it offered little that we had not already seen, so most of us decided to explore the north-east end of the island where, as on Pabbay, sand is blown over the slopes of a hill.

This ground is heavily grazed by sheep, and much of it has been cultivated in the past (the population of Berneray at its maximum was 2,000; now 200 or so). In the furrows of old ridge-and-furrow lines we found Scapania aequiloba, Leiocolea alpestris and abundant Moerckia hibernica. Rock protrudes through the sand around the west side of the foot of the hill. Here we found eight or nine species of Barbula, Orthotrichum rupestre, Gymnostomum recurvirostrum, Porella obtusata and Trichostomum crispulum. Further round the north side of the hill, on the lower slopes we found large quantities of Myurium hochstetteri, growing in beautiful shining tufts. We also looked at several flushes (Leiocolea bantriensis, Philonotis calcarea) and some damp rock outcrops. Some of the rock habitats were particularly interesting. We recorded Amblyodon dealbatus, Radula aquilegia, Leiocolea badensis, Harpalejeunea ovata, Lejeunea lamacerina, Frullania fragilifolia, F. teneriffae, Aphanolejunea microsopica and Platydictya jungermannioides*. Ron Porley visited the sand dunes and saw Catoscopium nigritum, Amblyodon dealbatus, Meesia uliginosa, Drepanocladus revolvens, etc., and walked much further than the rest of us.

I was helped greatly in planning the meeting and finding suitable accommodation by the local staff of Scottish Natural Heritage, Dr Mary Elliott and Miss Norah Macphee. Some of the new vice-county records (*) have still to be confirmed.

Peter Pitkin


The Uists & Benbecula