Managing for Scotland’s mountain plants

Land management recommendations for mountain plants – a summary Maintain light grazing regimes

Too much grazing limits the growth of these plants and causes soil erosion.

Do not burn Mountain plants grow slowly and cannot recover from burning.

Protect against physical damage Maintain footpaths; direct foot and bike traffic; site developments appropriately.

The arctic-alpine world of Scotland

Climb to the highest summits and ridges of the Scottish hills and you come to more than a feeling of achievement or a better view. You are in a different world, high above the enclosed fields and settled glens, and above the tree line. This is a quiet world, where the vegetation is no more than a thin skin of life over the ancient eroded bones of the hills. It is silent apart from the wind, the piping calls of birds, and the sound of running water – a special world with its own qualities of wilderness.

It is also home to a wide range of arctic-alpine mountain plants. This leaflet provides guidance for land managers on looking after the mountain habitat for these species.

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4 Managing for Scotland’s mountain plants 5

Mountain speciesHigh on mountains, the annual growing season is too short and the climate and soils too inhospitable for trees and many shrubs. For mountain plants, however, it’s a different story. Because they are slow-growing, they cannot always compete at lower altitude with faster-growing plants for light and space, but they thrive on the high hills.

Arctic-alpine communities are made up of...Dwarf shrubs such as heather (Calluna vulgaris) and blaeberry (Vaccinium myrtillus).

Grasses such as mat-grass (Nardus stricta) and tufted hair-grass (Deschampsia cespitosa).

Sedges such as stiff sedge (Carex bigelowii).

Mosses, liverworts and lichens, which are more common and conspicuous in these communities than in most other types of vegetation. Some arctic-alpine vegetation consists of mats and patches of these plants and fungi with a mere sprinkling of flowers.

Many of the species growing on the peaks and ridges are equally at home throughout the uplands and upland margins; others are more specialised. As you climb a hill, for example, notice the vegetation around you becoming shorter and sparser. Trees and shrubs give way to heather moorland, blanket bogs and wet, heathy mixtures of deer grass (Trichophorum germanicum) and purple moor-grass (Molinia caerulea). With increasing altitude, heaths are replaced by grasslands and finally you’ll find yourself walking on a springy mat of dwarf heather or blaeberry, or with a soft carpet of mosses or lichens under your boots.

The following species are noticeable indicators that you are above the tree line and in the ‘montane zone’:

Heather (Calluna vulgaris) With its prostrate growth form – where the shoots grow in a thin, wind-pruned layer over the ground rather than as upright little bushes – heather is one of the most obvious indicators of arctic-alpine (montane) vegetation. Alpine clubmoss (Diphasiastrum alpinum) With its pale blue-green, branching, flattened shoots creeping among the dwarfed heather and mosses, this is one of the first characteristic arctic-alpine species you will notice as you reach the upper parts of a hill.Stiff sedge (Carex bigelowii) This sedge grows in short, grey-green tufts and clumps, and has distinctive tight, black flowering heads at the top of stiff, upright stems.

Least willow (Salix herbacea) The smallest of our willows, this diminutive creeping shrub is barely taller than the mountain mosses it grows amongst. The bright green, shining leaves grow crowded together on dark, wiry stems. The catkins are conspicuous in late spring, as are the masses of fluffy seeds after midsummer. Spiked woodrush (Luzula spicata) The grass-like clumps of this species grow in open gravelly places and although the leaves themselves are quite inconspicuous, the dark, drooping flower heads are not hard to spot. Moss campion (Silene acaulis) Moss campion isn’t common everywhere, except in the far northwest and on richer rocks such as the mica-schists of Perthshire, but it is a distinctive and easily recognised plant with its neat cushions of bright green, narrow leaves and brilliant pink flowers in late spring and early summer.

Heather (Calluna vulgaris)

Moss campion (Silene acaulis)

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Montane grasslands and sedge or rush swards In Scotland, we’re used to regarding grassy hills as less natural or less valuable for nature conservation than heathery ones, seeing the grass swards as evidence of excessive burning and hard grazing. At low to moderate altitudes, this is almost always true but above the tree line, some grasslands are near-natural communities, occurring where the climate is too severe or the winter snow-lie is too prolonged for dwarf shrubs to be able to thrive. Look out for:

• Mat-grass (Nardus stricta) forming pale, tussocky swards on high slopes, in hollows and gullies and on plateaux where snow lies late in spring.

• Tufted hair-grass (Deschampsia cespitosa), the rich bright green swards of which clothe the steep back walls and upper slopes of sheltered corries. It also marks out places where snow lies late in spring and which are irrigated by the water from melting snow or dripping cliffs.

• Stiff sedge (Carex bigelowii) growing in damp montane soils.• Three-leaved rush (Juncus trifidus) on exposed summits and

rocky ridges and plateaux.

Where the underlying rocks are rich in calcium, you can find alpine grasslands with a dazzlingly rich array of species, including moss campion (Silene acaulis), alpine lady’s mantle (Alchemilla alpina), mossy cyphel (Minuartia sedoides), alpine bistort (Persicaria vivipara), alpine meadow-rue (Thalictrum alpinum) and, more locally, mountain avens (Dryas octopetala) growing in a short, velvety-green sward of grasses and sedges.

Montane blanket bog Blanket bogs on the high ground look quite different from those of lower ground. They have a shorter, greener sward, with the place of heather taken by blaeberry (Vaccinium myrtillus), bog bilberry (Vaccinium uliginosum) and crowberry (Empetrum nigrum). Many of them also have a thick sprinkling of cloudberry (Rubus chamaemorus) with its distinctive rounded leaves, attractive white flowers and spikes of orange berries in late summer.

Under the flowering plants is a richly coloured quilt of large, conspicuous mosses such as Sphagnum capillifolium, Rhytidiadelphus loreus, Hylocomium splendens and Pleurozium schreberi. The uncommon dwarf birch (Betula nana) is a local rarity in this type of vegetation.

Montane dwarf-shrub heath With increasing altitude and exposure, plants such as heather and blaeberry diminish in size, and on high, wind-exposed summits and ridges, they form a sward barely 5cm high. Among the creeping shoots of heather, blaeberry and crowberry (Empetrum nigrum), you’ll find an array of small plants such as stiff sedge (Carex bigelowii), alpine clubmoss (Diphasiastrum alpinum), mountain everlasting (Antennaria dioica), dwarf azalea (Kalmia procumbens) and arctic bearberry (Arctostaphylos alpinus).

Montane moss heaths Above the altitudinal limit of dwarf shrubs, the high ridges, summits and plateaux are clothed with a soft grey blanket of the woolly fringe-moss (Racomitrium lanuginosum) dotted with small plants such as blaeberry, stiff sedge and least willow. Known as Racomitrium heath, this type of vegetation is widespread in Scotland and also on the high hills of England, Wales and Ireland. It is exceptionally rare in the rest of the world.

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Fir clubmoss (Huperzia selago), crowberry (Empetrum nigrum) and heather (Calluna vulgaris)

Managing for Scotland’s mountain plants

Six key plant communities found on Scotland’s mountains are:

Snow-bedsPlant communities of snow-beds, the hollows and gullies where snow accumulates each winter and lies long into spring, are among the greatest treasures of the Scottish hills. They are extraordinarily varied and diverse although to the casual eye, they appear to be no more than bare ground with a thin sprinkling of flowering plants, sedges and grasses in a broken carpet of mosses and liverworts.

The vegetation in the longest lying snow-beds may be free of snow for only six weeks each year, so the plants that grow there have to make the best use of every minute of their brief growing season. Even as the snow withdraws, the leaves of the characteristic mosses and liverworts unfurl in a dazzling array of green and gold. Within days, there’s a display of capsules on hair-like stems, the annual miracle of renewed life in this most challenging of habitats.

There is enormous diversity here, too. A brief look through a hand lens or through the wrong end of a pair of binoculars reveals the beautifully intricate mixtures of tiny tufts and creeping shoots of mosses and liverworts, with as many as eight species recorded on a square centimetre of ground.

Other plants to look out for include:Least willow (Salix herbacea), a small creeping willow. Fir clubmoss (Huperzia selago), a tufted upright plant that looks a bit like a mini conifer.Starry saxifrage (Saxifraga stellaris), with its 5-10 white flowers on a spike up to 20cm tall. Heath bedstraw (Galium saxatile), a creeping bedstraw with tiny white flowers.Sibbaldia (Sibbaldia procumbens), a very rare, small flowering plant with greenish-yellow flowers.Dwarf cudweed (Gnaphalium supinum), with its small, greyish leaf rosettes. Almost confined to snow-bed vegetation.Alpine lady fern (Athyrium distentifolium) and mountain male-fern (Dryopteris oreades), both characteristic of snow-beds, where the annual covering of snow protects these plants from frosts.

Mires and springsUpland springs are distinctive, with bright cushions of mosses and liverworts at the source of the water. The most common plants are starry saxifrage (Saxifraga stellaris), blinks (Montia fontana), the mosses Philonotis fontana and Dicranella palustris, and the liverwort Scapania undulata.

Mires are tracts of vegetation that mark out the places where water flows on or just below the surface of the ground. Among the most common and conspicuous species here are sedges such as Carex nigra, C. curta and C. rostrata. They grow through a soft and spongy carpet of mosses including some Sphagnum species.

Plantlife’s leaflet on Looking after bryophytes in Scotland’s springs and flushes gives more information on these plant communities. You can download it at www.plantlife.org.uk/uploads/documents/24028_Bryophytes.pdf

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Sibbaldia (Sibbaldia procumbens)

Fountain moss (Philonotis fontana) with alpine lady’s mantle (Alchemilla alpina) and starry saxifrage (Saxifraga stellaris)

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Managing for Scotland’s mountain plants

10 11A management guide

Why are arctic-alpine communities important?Compared with hills on the European mainland, Scotland’s mountain habitats have an oceanic climate with relatively cool summers, mild winters, high and frequent rainfall and persistent low cloud. Above the altitudinal limit of woodland, our montane vegetation is different from that found elsewhere in Europe, with our prostrate heather heaths and Racomitrium lanuginosum heaths in particular being almost confined to Britain and Ireland.

Arctic bearberry (Arctostaphylos alpinus)

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Managing for Scotland’s mountain plants

Arctic-alpine vegetation, and especially snow-bed vegetation, is a remarkable link with the past. Snow-bed vegetation in Scotland is a precious relict of the late-glacial and early post-glacial landscape, when the ice of the last Pleistocene glaciation was beginning to retreat, leaving a scoured landscape of rock and gravel, cold clear lakes and cascading streams.

Arctic-alpine communities are among our most natural landscapes, owing more to the effects of their habitat – ie, climate, aspect, altitude and soil chemistry – than to present or past land management.

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Threats to arctic-alpine vegetationA changing climate can threaten arctic-alpine vegetation all too easily. If the climate becomes warmer or snow-lie less reliable, there is nowhere else here for these plants to go. Besides climate change, threats include...

PollutionDespite the distance from human activities in towns and cities, the effects of atmospheric pollution reach even to the tops of the hills. Sulphates and nitrogen oxides from polluted snow are released in disproportionate amounts in a short time when snow melts, and the high and frequent rainfall means more exposure to dissolved pollutants all year round. Nitrogen from vehicle exhausts has been measured in snow-bed mosses on Bidean nam Bian, over 1,000 metres higher than the traffic-choked A82 in Glen Coe. Excessive levels of these nutrients can disrupt the growth of plants which evolved in times and places where the air and water were clean.

GrazingGrazing of the high ground by deer and sheep, especially in summer when they escape from flies, can also prove challenging to the vegetation. While the direct effects of grazing seem slight over much of the high ground in the Highlands, the more southerly hills of the Southern Uplands and Galloway do show the long-term effects of heavy grazing, with Racomitrium heaths replaced by acid grasslands or swards of Carex bigelowii, and with dwarf shrubs lost from blanket bogs.

However, no grazing at all is as unnatural and potentially damaging as too much. Upland vegetation in Scotland has always been grazed and at some periods in the past by a greater diversity of herbivores than we have today. Grazing is probably partly responsible for the persistence of arctic-alpine vegetation at comparatively low altitudes in the south and west of Scotland, as it reduces the competition from larger plants which would come to predominate in the absence of grazing.

Erosion Physical damage caused by walkers and animals is another problem, specially in snow-beds and on the steep back walls of corries, where the fragile, crumbly, frost-churned soils are easy to disturb and where erosion is easily initiated. Once the skin of vegetation is broken, wind, rain and frost soon strip the soils, leaving bare ground which takes many years to revegetate.Arctic-alpine vegetation can also be damaged by high-altitude recreational facilities – such as ski resorts, mountain railways and access tracks for stalking and shooting – as can inappropriately-sited wind farms and telecommunications masts.

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Eroded track caused by vehicular access

Managing for Scotland’s mountain plants

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Suitable managementBenign neglectThe best management for arctic-alpine vegetation could be described as benign neglect. Light grazing is really all they need to keep them in good condition. The further south, the more important this is. The lower limit of the montane zone does seem to be affected by grazing, keeping the swards short and reducing competition for the smaller, slower-growing species. Although total removal of grazing is done to encourage woodland and scrub regeneration, it has resulted in more prolific growth of the more robust species at some sites, as well as losses or potential losses of characteristic montane communities and species.

Burning Heaths and bogs at high altitudes do not need burning to keep them in good condition: the severe climate restricts the growth of the shrubs and they never become a tall, leggy fire hazard as they can at lower altitudes. Indeed, burning is damaging to these communities, and a single fire can eliminate the characteristic lichens, mosses and liverworts as well as sensitive plants such as dwarf juniper and mountain azalea.

Contacts for further advice and informationPlantlife Scotland Balallan House Allan Park Stirling FK8 2QG Tel: 01786 478509 Email: scotland@plantlife.org.uk www.plantlife.org.uk/scotland

Scottish Natural Heritage www.snh.gov.uk

British Bryological Society www.britishbryologicalsociety.org.uk

The British Lichen Society www.britishlichensociety.org.uk

Physical damageTrampling damage and soil erosion happen more easily at high altitudes, because the vegetation and soils are fragile, the climate severe and the rates of recolonisation slow. Footpaths on popular hills should be well-maintained so that walkers are not tempted to walk to one side in order to by-pass erosion or wet ground. If possible, mountain bikers need to be encouraged to stick to hard trails or rocky ground, and not to ride over vegetation.Wind farms, access tracks for shooting and stalking, and other developments such as mobile phone masts and weather stations should also avoid the high montane ground.

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Managing for Scotland’s mountain plants

We are PlantlifeWild plants and fungi play a fundamental role for wildlife, and their colour and character light up our landscapes. But without our help, this priceless natural heritage is in danger of being lost. Plantlife is the charity that speaks up for Scotland’s wild flowers, plants and fungi. From the open spaces of our nature reserves to the corridors of Holyrood, we’re here to raise their profile, to celebrate their beauty and to protect their future.

Join us in enjoying the very best that nature has to offer Scotland’s countryside. Save it with flowers

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© December 2015

This guide was written by Alison Averis for Plantlife Scotland. Cover photograph: Alpine azalea (Loiseleuria procumbens) ©Laurie CampbellDesign: evansgraphic.co.uk

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