Meeting Report: The Flora of the Grey Mare's Tail Nature Reserve

18 January 2013
Richard Clarkson (National Trust for Scotland)

On Friday 18th January, members of the Dumfriesshire & Galloway Natural History and Antiquarian Society were given an entertaining and enlightening lecture with stunning photography by Richard Clarkson on the Flora of the Grey Mare's Tail Nature Reserve, owned by the National Trust for Scotland and containing White Coomb, the highest point (821 m, or 2,694 ft) in Dumfriesshire. Richard, a native of Herefordshire in England, moved to Scotland, to Caithness, in 1990, drawn by his interest in Nature. He continued to develop that interest, always in Scotland apart from time spent at Staffordshire University from where he graduated in Ecology, until he was appointed Ranger at the Reserve in 2010.

He began his lecture with the geology of the Grey Mare's Tail area, its underlying rocks being formed 400–500 million years ago far south of the equator before tectonic drift took them to their present location. The Grey Mare's Tail itself, dropping 200 feet and the result of a glacially-formed Hanging Valley, is the fifth highest cascade in the UK. It is fed by Loch Skeen, home to a population of vendace (Coregonus vandesius), Britain's rarest fish, formerly found only at Derwent, Bassenthwaite Lake, and the Castle and Mill Lochs at Lochmaben. It has since become extinct at the last three sites, although not before some of the Bassenthwaite vendace were brought in the 1990s to Loch Skeen, where they now appear to being doing well. In addition to the Grey Mare's Tail, the Reserve has a second waterfall, Dob's Linn, a world famous geological Site of Special Scientific Interest (SSSI) where Charles Lapworth, a Galashiels schoolteacher and a giant of Geology, studied graptolite fossils and proposed (and named) a new geological period, the Ordovician. He was also the first to recognise that older rocks could be thrust over younger, a concept that at the time conflicted with orthodoxy.

Richard then discussed the fauna of the Reserve. It has a number of bird species — peregrine falcons (whose nest can at certain times of the year be viewed by CCTV), meadow pippets and the very rare ring ouzel (the Reserve has only 1–2 nesting pairs of this migrant from North Africa). Other bird species include wheatear, stonechat, red grouse and ravens, as well as transients such as short-eared owls. Grazers include sheep (the NTS does not own the grazing rights to the Reserve), a population of wild goats of ancient lineage and a small number of mountain hares, with occasional roe deer.

He then moved on to the main part of his talk, the flora, beautifully shown on superb slides (with not a love-'em-or-loathe-'em wind turbine in shot!) The Reserve is a European Special Area of Conservation and a Site of Special Scientific Interest with respect to its flora. Plants of the Reserve, the terrain of which allows some rarer montane (alpine/subalpine) species to survive in crevices inaccessible to grazers, are found in eight distinct habitats of European importance. Within the Habitats, there is one Endangered, 17 Nationally Rare and 12 Regionally Rare species. The highest Habitat, Montane Grassland, has Woolly Fringe-moss (Racomitrium lanuginosum) and Heath Bedstraw (Galium saxatile). At a lower level are Alpine and Subalpine Heaths, the principal plants here in the Reserve being Blaeberry, Cloudberry, Crowberry and Dwarf Cornel. Dry Heaths are a third Habitat, comprising mainly heathers — Bell, Brush and Cross-leaved heath — Blaeberry and an orchid, Lesser Twayblade (Listera cordata). This population contrasts with that of the Soligenous Mires Habitat, kept wet by late snow melt and water run-off, and which supports Starry and Golden Saxifrage, the insectivorous Butterwort, Chickweed Willowherb, a declining population of Hairy Stonecrop (now growing in only one flush) and the very rare Alpine Foxtail, found only in the Highlands, the Moffat Hills, a few sites in the Borders and northern Pennines. Outside these sites, it is found only in Svalbard.

Another Habitat in the Reserve is Blanket Bog, comprising sphagnum, heather, Common and Hare's-tail Cottongrass, Cross-leaved Heath, Lousewort and the splendidly named Tormentil (Potentilla erecta), once considered an aphrodisiac and still used as an astringent, a red dye, as the basis for a Black Forest liqueur called Blutwurz and as an anti-diarrhoeal. Acidic Scree, another Habitat, supports Parsley Fern, and then there are the Habitats of Tall Herb Communities and Plants in Crevices, the rarer plants mentioned earlier beyond the reach of grazers.