A survey of the vegetation of Ben Nevis - Scottish Natural Heritage

Scottish Natural Heritage Commissioned Report No. 090 (ROAME No. F02LD01)
1 INTRODUCTION
1.1 The study area
This project was commissioned by Scottish Natural Heritage. The purpose of the project was to collate
existing information on the vegetation and flora of the Ben Nevis Site of Special Scientific Interest (SSSI) and
Special Area of Conservation (SAC), to survey and map the vegetation and to assess the populations of rare
vascular plant species. The SAC is within the SSSI boundary; for the most part the boundaries of the two
are coincident.
The survey area is over 90km2 in area. It includes Ben Nevis (1344m) and its outliers Meall an t-Suidhe
(711m) and the two hills called Carn Dearg (the northern one is 1214m; the southern one is 1020m); the
ridge of Carn Beag Dearg (1010m), Carn Dearg Meadhonach (1179m) and Carn Mór Dearg (1220m);
Aonach Mór (1221m), Aonach Beag (1234m) Sgurr a’ Bhuic (963m), Meall Cumhann (698m), Tom na
Sròine (918m), Stob a’ Chùl Choire (1068m) and the ridge known as the Grey Corries. This ridge rises to
the distinct peaks of Sgurr Chòinnich Beag (963m), Sgurr Chòinnich Mhór (1094m), Stob Coire Easain
(1080m) and its northern outlier Beinn na Socaich (1007m), Stob Coire an Laoigh (1116m), Caisteal
(1106m), Stob Coire Cath na Sìne (1079m), Stob a’ Choire Lèith (1105m), Stob Choire Claurigh (the
highest point on the ridge at 1177m), Stob Coire na Ceannain (1123m) and its northern outliers Stob Coire
Gaibhre (958m) and Beinn Bhàn (843m). The study area is bounded to the west and south by Glen Nevis
and Coire Rath, to the north by the Leanachan Forest, and to the east by the Lairig Leachach. The lowest
part of the site is at the extreme north-western boundary where it descends to 30m above sea level.
Most of the site is owned by ALCAN Smelting & Power UK. A large area in the south-west, including the
summits of Ben Nevis and Aonach Beag, is owned by the John Muir Trust. A small area in the north is owned
by Forestry Commission Scotland. Ownership boundaries are shown in Map D in Appendix 5.
The land is now uninhabited, though there is a bothy at Steall in upper Glen Nevis and another at the fords
of the Allt a’ Cùl Choirean in the Lairig Leacach. There is a hut for the use of climbers in Coire Leis. It is
known as the Charles Inglis Clark or C.I.C. hut, in memory of a climber who was killed in the First World
War. The study area is grazed by sheep, red deer and roe deer as well as by small mammals including
mountain hare and field vole. These hills are popular with walkers and climbers. The ‘Tourist Path’, originally
the pack-pony route, to the top of Ben Nevis ascends from Achintee, in the far west of the study area, to the
summit of Ben Nevis. There are well-used paths along upper Glen Nevis and the Allt a’ Mhuillin glen, and
a bulldozed track along the Lairig Leacach as far as the bothy. There are many bulldozed tracks in
Leanachan Forest to the north, and a few of these continue a short distance out of the forest into the lower
northern parts of the site.
1.2 Geology and geomorphology
The geology in this part of Scotland is complex, with igneous intrusions through a mixture of sedimentary
and metamorphic rocks of both Moine and Dalradian age (British Geological Survey 1979). Most of the
study area consists of Moine and Dalradian schist, slate, phyllite and mica-schist. Some of the schist, notably
on Aonach Beag and Beinn na Socaich, is remarkably base-rich. The summit and the northern cliffs of
Ben Nevis are made of andesite and basaltic lavas and tuffs. A granite intrusion forms the southern slopes
of Ben Nevis and also the ridge of the Carn Dearg peaks. A thin band of Dalradian limestone runs through
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