Exploring Quinag: Uidh an Leothaid
The Uidh an Leothaid (burn of the slope) is the main feeder for Loch an Leothaid, in the upper part of Gleann Leireag. It rises from the base of scree slopes north-east of the Bealach Leireag on the west side of Quinag (NC196283), does a smart turn north-west and then flows along the base of a series of crags and into the loch (NC177296). Only the last 0.5km is, strictly, within the fence which marks the boundary of the JMT estate with that of Loch Assynt Lodge to the west, although the river itself may be the real boundary. Parallel to the fence, on its north-east, is the old track between Nedd and Ardvar to the north and Tumore on Loch Assynt to the south.
One of the remaining unexplored 1km squares in our current survey of Quinag was NC1829, on the course of this river a short way up from the loch (map, photo 1), where the underlying Lewisian gneiss is cut by two narrow mafic (basic) dykes. This area is a fair distance from the road, so we waited for reasonable weather, which was forecast for 18th August 2023.
Walking in and making a start
We parked at the northern end of the Nedd path at 0940 hrs (NC156313), and set off. The track is little used nowadays, and was quite overgrown, particularly through the large shieling of Ruigh Dorch (NC161307), where it was hidden under bracken more than a metre high (photo 2, looking back). This shieling used to be largely open grassland, but is much changed (although 2023 has been a bumper year for bracken).
We arrived at the JMT boundary gate at 1050 hrs and the north-west corner of NC1829 at 1130 hrs. Animal life was scarce on the way, apart from a common darter dragonfly Sympetrum striolatum and a couple of windblown Scotch argus butterflies.
A wet crag just east of the track (NC180299), which we had noted before (Exploring Quinag: Loch an Leothaid, posted 24th November 2022), appears to be on the line of one of the dykes. We logged the first 30 species in its vicinity, including northern bedstraw Galium boreale, purging flax Linum catharticum , and yellow saxifrage Saxifraga aizoides, indicating some base-flushing. Nearby, sweet vernal grass Anthoxanthum odoratum bore the fruiting bodies of the ergot fungus Claviceps purpurea.
First tributary
We then walked south-east up the gently-rising track until we met the first substantial tributary burn (NC182296), dropping down through a small gorge cut through the dyke rock (photo 3). We spent the next couple of hours in this area, which had a good variety of habitats, and also provided somewhere comfortable for lunch.
A gravelly fan at the mouth of the gorge supported damp, slightly basic, grassland (photo 4). This had a good variety of grasses, with predictable associates such as sneezewort Achillea ptarmica, flea sedge Carex pulicaris, yellow pimpernel Lysimachia nemoralis, primrose Primula vulgaris and white clover Trifolium repens, many of them uncommon in moorland landscapes. The soils were also fertile enough to have a population of earthworms, the evidence being a single (apparently isolated) mole hill on a steep bank.
Gwen had a look at the rocks outcropping in the gorge, with some small returns, including goldenrod Solidago virgaurea. She also spotted two small holly trees further up the watercourse, presumably bird-sown (photo 5). Other trees were very scarce and, unusually, neither downy birch nor rowan were noted that day.
Flushes and a second tributary
At 1345 hrs we continued south-east up the track (photo 6), passing a couple of stony flushes containing black bog-rush Schoenus nigricans (photo 7), with two of its frequent associates, dioecious sedge Carex dioica and pale butterwort Pinguicula lusitanica. We had already logged elsewhere tawny sedge Carex hostiana, broad-leaved cottongrass Eriophorum latifolium and lesser clubmoss Selaginella selaginoides. That gave us almost the full set of the widespread base-indicators which enliven botanising on the gneiss throughout Assynt. Water leaching from the mafic dykes is the likely source of the relevant minerals.
Shortly afterwards (at NC183294), we forded a second major tributary burn, tumbling down some bouldery falls (photo 8) and flanked by wet grassland, adding species such as opposite-leaved golden saxifrage Chrysosplenium oppositifolium and blinks Montia fontana.
Over to the river
We had originally planned to continue up the track to list a corner of the next 1km square (NC1928) but, given that we had already spent nearly five hours in the field, and still had a longish walk out, we turned round and diverted our attention to the main course of the river (photo 9).
An obvious feature was a 3m high bank eroded by spate waters (NC182294, photo 10). The upper half was solid peat, presumably laid down over a very long period, but just above its base there was a layer of pale fragments of birch wood. This might have been flood debris from even higher up, but more likely the remains of living trees originally rooted in shallow peat lying on the fine silts and sands which occupied the lower half of the profile, and later killed off by more peat deposition.
We will leave the detailed interpretation of this cross-section to experts, but it gave us some impression of events on Quinag extending back perhaps 10,000 years before the present.
Beach, ox-bow and walking out
A stony beach opposite the bank looked promising; it actually yielded nothing new, but did have some of the indicators of local base-richness, such as fairy flax Linum catharticum and wild thyme Thymus polytrichus.
However, a short distance downstream there was a cut-off meander or ox-bow. Its drier parts contained a slightly odd mix of new species including wood horsetail Equisetum sylvaticum, wood soft-grass Holcus mollis and valerian Valeriana officinalis, perhaps relics of former more wooded conditions. The wetter parts (photo 11) had, more predictably, bog pondweed Potamogeton polygonifolius and the dainty lesser bladderwort Utricularia minor.
We then retraced our steps down the track to the first tributary burn for a short tea break and at 1510 hours turned for home, reaching the road, fairly weary, two hours later. Faunal observations on the way back included a caterpillar of the ruby tiger moth and a small toad.
The higher plant total for seven hours in the field was a modest 105 species, but any regrets at not finding more were offset by views of the stunning south-western ramparts of Quinag, rearing up above us.
Ian M. Evans and Gwen Richards
All photos by Gwen Richards