|IPA Factsheet - Ben Alder and Aonach Beag|
Site Description Prior to the nineteenth century the area was farmed and the uplands grazed seasonally, mainly by cattle. When the area was made into farms, the land was grazed by sheep. Sheep were removed from the ground in the southern area in the 1840s and from the northern area 40-50 years ago. Historical references describe a dense scrub of pine, birch, holly, rowan and possibly hazel on southern facing slopes along the side of Loch Ericht. Two small blocks of forestry were planted at the northern end of the site in the mid-twentieth century. There has been some moor gripping (draining) in the blanket bogs in the past. The major land use is stalking of red deer and both major estates hold significant populations of deer. Grouse and ptarmigan are also shot in small numbers. Parts of the area are managed for grouse but not intensively. Fishing for brown trout takes place on Loch Pattack and Loch Ericht, both from the shore and boats. There is no farming or active forestry on the SSSI but several relatively small exclosures have been erected along Loch Ericht to protect tree seed sources and allow natural regeneration of relict native woodland. Conifer woods adjacent to the SSSI have been opened up to provide shelter for deer, reducing the pressure within the SSSI. There are several “Munros” and “tops” in the area` which attract keen walkers, climbers and cross-country skiers. Numbers of users are lower than on many other hills because of the remoteness of the area. Access is by foot or mountain bike, and involves a walk or cycle of at least 10 km before the mountains are reached. Walkers frequently camp or use one of the two bothies on the site. A car park for walkers has been constructed near Dalwhinnie by one of the landowners and there has also been considerable recent investment in sympathetically improving the estate path network for stalking and walkers. Footpath improvement has encouraged walkers to use the paths and has reduced pressure on the surrounding habitat and disturbance to ground nesting birds.
Botanical Significance Ben Alder and Aonach Beag represent Alpine and Boreal heaths in the central Scottish Highlands. A wide range of heaths form extensive stands, including Calluna vulgaris – Cladonia arbuscula, Vaccinium myrtillus – Cladonia arbuscula, Vaccinium myrtillus – Racomitrium lanuginosum and Vaccinium myrtillus – Rubus chamaemorus heaths. The representation of reindeer Cladonia lichens and woolly fringe-moss Racomitrium lanuginosum is intermediate between the eastern and western Highlands. The rockier heaths provide suitable habitat for eastern outlying stations of northern Atlantic liverworts. Ben Alder and Aonach Beag are representative of high-altitude Alpine and subalpine calcareous grasslands in the central Highlands, where the habitat is very local owing to the infrequent occurrence of calcareous rocks at high altitude. Both Festuca ovina – Alchemilla alpina – Silene acaulis dwarf-herb and Dryas octopetala – Silene acaulis ledge communities are well-represented, especially the latter. The widespread arctic-alpines purple saxifrage Saxifraga oppositifolia and yellow saxifrage S. aizoides are frequent, while rarer species that are widespread on the site include cyphel Minuartia sedoides, alpine meadow-grass Poa alpina, hair sedge Carex capillaris, black alpine-sedge C. atrata and alpine speedwell Veronica alpina. This area is particularly rich in plant species including the mountain avens Dryas octopetala, cyphel Minuartia sedioides, sibbaldia Sibbaldia procumbens and starwort mouse-ear. Unusually, grazing levels appear to be low enough to allow the development of mountain avens heath on slopes open to grazing animals. The low grazing levels also allow the exceptional development of moderately large populations of montane willows, including woolly willow Salix lanata, conforming to Sub-Arctic Salix spp. scrub, for which the site is also selected. The transition between these two habitat types is unusual. Ben Alder and Aonach Beag are representative of high altitude flushes in the central Highlands. Both open flushes of Carex demissa – Saxifraga aizoides mire and more closed flushes of Carex saxatilis mire are well-represented. The flushes are well-developed but localised and are notable for the occurrence of the rare hare’s foot sedge Carex lachenalii and scorched alpine-sedge Carex atrofusca, which is known to occur in only two other locations in the SAC series. Other characteristic species include three-flowered rush Juncus triglumis, Scottish asphodel Tofieldia pusilla, sheathed sedge Carex vaginata, alpine bistort Persicaria vivipara and the moss Blindia acuta. Other uncommon species include hair sedge Carex capillaris and alpine cat’s-tail Phleum alpinum. These ranges of hills have the largest area of ground above 1000 m in Britain outside of the Cairngorms and the extent of Siliceous alpine and boreal grassland is correspondingly high. The range of communities is representative of the higher hills of the central Highlands, with all the NVC types associated with the habitat represented. The most extensive communities are Nardus stricta – Carex bigelowii grass-heath and Carex bigelowii – Racomitrium lanuginosum moss-heath, the latter with an unusual occurrence of a species-rich sub-type following a band of high-altitude limestone. This site represents one of only six sites outside of the Cairngorms and Ben Nevis with extensive late-lie mossy snow-beds holding Polytrichum sexangulare – Kiaeria starkei and Salix herbacea – Racomitrium heterostichum snow-bed communities. Various rare plants occur in the snow-beds, including starwort mouse-ear Cerastium cerastoides and the bryophytes Dicranum glaciale, Marsupella condensata and Nardia breidleri. Carex bigelowii – Polytrichum alpinum sedge-heath attains its largest extent outside of the eastern Highlands. This site represents high-altitude (950 m) Sub-Arctic Salix spp. scrub on highly calcareous schist and limestone. It has the largest known population in the UK of woolly willow Salix lanata, the rarest of the sub-Arctic willows. Downy willow S. lapponum and net-leaved willow S. reticulata are frequent, and whortle-leaved willow S. myrsinites is also represented. The willows are associated with an area of Alpine and subalpine calcareous grasslands on steep, rocky and remote ground. The wide range of plant communities contains rare and scarce plants which make up the important vascular plant assemblage. This includes blue heath Phyllodoce caerulea which has only been found in three locations in the United Kingdom all of which are in the Ben Alder and Aonach Beag mountains. The area is considered exceptional for its bryophytes associated with upland habitats and long snow cover, including nationally rare species. Some Northern Atlantic liverworts have their eastern outposts in the Ben Alder range and these include Scapania nimbosa and Herbertus aduncus. The area, particularly the limestone outcrop, supports a rich and diverse lichen assemblage with many rare species present of which four are only found at this site. One very distinct species found on the limestone is goblin lights Catolechia wahlenbergii, which is an eerie yellow-green colour.
General Habitat Description Ben Alder and Aonach Beag IPA represents a large and remote area lying between Lochs Ericht and Laggan, 11km southwest of Dalwhinnie. Ben Alder is 1148 metres above sea level, rising from a plateau with more than 300 hectares of land over 1000 metres. Both Ben Alder and Aonach Beag are surrounded by dramatic corries, lochans, and steep rocky slopes, giving way to blanket bogs and heath on the more gentle slopes. The mountains are composed largely of acidic Dalradian schists with a band of metamorphosed limestone, which outcrops at one location but crosses three coiries. The area exhibits a great diversity of habitats and some fine examples of the vegetation communities associated with prolonged snow cover. These mountains, in comparison with many of the other mountains of western Inverness-shire have suffered less from heavy grazing, and this, together with their isolated position and geology, has resulted in one of the most ecologically varied mountain systems in the western Grampians.
Conservation Issues When monitored between 2001-2005 the following were found to be in unfavourable condition: wet heaths, montane willow scrub (unfavourable and limited in extent), blanket bog habitats (unfavourable due to the extent of bare peat in places- possibly as a result of trampling by deer), vascular plant assemblage (difficulty in locating some rare and scarce plants previously found) The calcareous grasslands and tall herb communities have not yet been monitored (as of March 2010). Deer stalking has a low impact on the site as most deer are removed from the hill by pony. However grazing and trampling by red deer is the most important factor affecting the various features of interest at this site and identifying and achieving appropriate grazing levels are major challenges. Current deer control is beneficial to nearly all interests of the site but may be suppressing or limiting the development of montane scrub and tall herb communities. The effects of climate change may affect the extent and composition of some of the more important arctic-alpine communities.